linux_dsm_epyc7002/net/tipc/link.c

2646 lines
72 KiB
C
Raw Normal View History

/*
* net/tipc/link.c: TIPC link code
*
* Copyright (c) 1996-2007, 2012-2016, Ericsson AB
* Copyright (c) 2004-2007, 2010-2013, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "core.h"
tipc: clean up handling of message priorities Messages transferred by TIPC are assigned an "importance priority", -an integer value indicating how to treat the message when there is link or destination socket congestion. There is no separate header field for this value. Instead, the message user values have been chosen in ascending order according to perceived importance, so that the message user field can be used for this. This is not a good solution. First, we have many more users than the needed priority levels, so we end up with treating more priority levels than necessary. Second, the user field cannot always accurately reflect the priority of the message. E.g., a message fragment packet should really have the priority of the enveloped user data message, and not the priority of the MSG_FRAGMENTER user. Until now, we have been working around this problem in different ways, but it is now time to implement a consistent way of handling such priorities, although still within the constraint that we cannot allocate any more bits in the regular data message header for this. In this commit, we define a new priority level, TIPC_SYSTEM_IMPORTANCE, that will be the only one used apart from the four (lower) user data levels. All non-data messages map down to this priority. Furthermore, we take some free bits from the MSG_FRAGMENTER header and allocate them to store the priority of the enveloped message. We then adjust the functions msg_importance()/msg_set_importance() so that they read/set the correct header fields depending on user type. This small protocol change is fully compatible, because the code at the receiving end of a link currently reads the importance level only from user data messages, where there is no change. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-14 03:08:11 +07:00
#include "subscr.h"
#include "link.h"
#include "bcast.h"
#include "socket.h"
#include "name_distr.h"
#include "discover.h"
#include "netlink.h"
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
#include "monitor.h"
tipc: enable tracepoints in tipc As for the sake of debugging/tracing, the commit enables tracepoints in TIPC along with some general trace_events as shown below. It also defines some 'tipc_*_dump()' functions that allow to dump TIPC object data whenever needed, that is, for general debug purposes, ie. not just for the trace_events. The following trace_events are now available: - trace_tipc_skb_dump(): allows to trace and dump TIPC msg & skb data, e.g. message type, user, droppable, skb truesize, cloned skb, etc. - trace_tipc_list_dump(): allows to trace and dump any TIPC buffers or queues, e.g. TIPC link transmq, socket receive queue, etc. - trace_tipc_sk_dump(): allows to trace and dump TIPC socket data, e.g. sk state, sk type, connection type, rmem_alloc, socket queues, etc. - trace_tipc_link_dump(): allows to trace and dump TIPC link data, e.g. link state, silent_intv_cnt, gap, bc_gap, link queues, etc. - trace_tipc_node_dump(): allows to trace and dump TIPC node data, e.g. node state, active links, capabilities, link entries, etc. How to use: Put the trace functions at any places where we want to dump TIPC data or events. Note: a) The dump functions will generate raw data only, that is, to offload the trace event's processing, it can require a tool or script to parse the data but this should be simple. b) The trace_tipc_*_dump() should be reserved for a failure cases only (e.g. the retransmission failure case) or where we do not expect to happen too often, then we can consider enabling these events by default since they will almost not take any effects under normal conditions, but once the rare condition or failure occurs, we get the dumped data fully for post-analysis. For other trace purposes, we can reuse these trace classes as template but different events. c) A trace_event is only effective when we enable it. To enable the TIPC trace_events, echo 1 to 'enable' files in the events/tipc/ directory in the 'debugfs' file system. Normally, they are located at: /sys/kernel/debug/tracing/events/tipc/ For example: To enable the tipc_link_dump event: echo 1 > /sys/kernel/debug/tracing/events/tipc/tipc_link_dump/enable To enable all the TIPC trace_events: echo 1 > /sys/kernel/debug/tracing/events/tipc/enable To collect the trace data: cat trace or cat trace_pipe > /trace.out & To disable all the TIPC trace_events: echo 0 > /sys/kernel/debug/tracing/events/tipc/enable To clear the trace buffer: echo > trace d) Like the other trace_events, the feature like 'filter' or 'trigger' is also usable for the tipc trace_events. For more details, have a look at: Documentation/trace/ftrace.txt MAINTAINERS | add two new files 'trace.h' & 'trace.c' in tipc Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:56 +07:00
#include "trace.h"
#include <linux/pkt_sched.h>
struct tipc_stats {
u32 sent_pkts;
u32 recv_pkts;
u32 sent_states;
u32 recv_states;
u32 sent_probes;
u32 recv_probes;
u32 sent_nacks;
u32 recv_nacks;
u32 sent_acks;
u32 sent_bundled;
u32 sent_bundles;
u32 recv_bundled;
u32 recv_bundles;
u32 retransmitted;
u32 sent_fragmented;
u32 sent_fragments;
u32 recv_fragmented;
u32 recv_fragments;
u32 link_congs; /* # port sends blocked by congestion */
u32 deferred_recv;
u32 duplicates;
u32 max_queue_sz; /* send queue size high water mark */
u32 accu_queue_sz; /* used for send queue size profiling */
u32 queue_sz_counts; /* used for send queue size profiling */
u32 msg_length_counts; /* used for message length profiling */
u32 msg_lengths_total; /* used for message length profiling */
u32 msg_length_profile[7]; /* used for msg. length profiling */
};
/**
* struct tipc_link - TIPC link data structure
* @addr: network address of link's peer node
* @name: link name character string
* @media_addr: media address to use when sending messages over link
* @timer: link timer
* @net: pointer to namespace struct
* @refcnt: reference counter for permanent references (owner node & timer)
* @peer_session: link session # being used by peer end of link
* @peer_bearer_id: bearer id used by link's peer endpoint
* @bearer_id: local bearer id used by link
* @tolerance: minimum link continuity loss needed to reset link [in ms]
* @abort_limit: # of unacknowledged continuity probes needed to reset link
* @state: current state of link FSM
* @peer_caps: bitmap describing capabilities of peer node
* @silent_intv_cnt: # of timer intervals without any reception from peer
* @proto_msg: template for control messages generated by link
* @pmsg: convenience pointer to "proto_msg" field
* @priority: current link priority
* @net_plane: current link network plane ('A' through 'H')
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
* @mon_state: cookie with information needed by link monitor
* @backlog_limit: backlog queue congestion thresholds (indexed by importance)
* @exp_msg_count: # of tunnelled messages expected during link changeover
* @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
* @mtu: current maximum packet size for this link
* @advertised_mtu: advertised own mtu when link is being established
* @transmitq: queue for sent, non-acked messages
* @backlogq: queue for messages waiting to be sent
* @snt_nxt: next sequence number to use for outbound messages
* @prev_from: sequence number of most previous retransmission request
* @stale_limit: time when repeated identical retransmits must force link reset
* @ackers: # of peers that needs to ack each packet before it can be released
* @acked: # last packet acked by a certain peer. Used for broadcast.
* @rcv_nxt: next sequence number to expect for inbound messages
* @deferred_queue: deferred queue saved OOS b'cast message received from node
* @unacked_window: # of inbound messages rx'd without ack'ing back to peer
* @inputq: buffer queue for messages to be delivered upwards
* @namedq: buffer queue for name table messages to be delivered upwards
* @next_out: ptr to first unsent outbound message in queue
* @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
* @long_msg_seq_no: next identifier to use for outbound fragmented messages
* @reasm_buf: head of partially reassembled inbound message fragments
* @bc_rcvr: marks that this is a broadcast receiver link
* @stats: collects statistics regarding link activity
*/
struct tipc_link {
u32 addr;
char name[TIPC_MAX_LINK_NAME];
struct net *net;
/* Management and link supervision data */
u16 peer_session;
u16 session;
u16 snd_nxt_state;
u16 rcv_nxt_state;
u32 peer_bearer_id;
u32 bearer_id;
u32 tolerance;
u32 abort_limit;
u32 state;
u16 peer_caps;
bool in_session;
bool active;
u32 silent_intv_cnt;
char if_name[TIPC_MAX_IF_NAME];
u32 priority;
char net_plane;
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
struct tipc_mon_state mon_state;
u16 rst_cnt;
/* Failover/synch */
u16 drop_point;
struct sk_buff *failover_reasm_skb;
struct sk_buff_head failover_deferdq;
/* Max packet negotiation */
u16 mtu;
u16 advertised_mtu;
/* Sending */
struct sk_buff_head transmq;
struct sk_buff_head backlogq;
struct {
u16 len;
u16 limit;
} backlog[5];
u16 snd_nxt;
u16 prev_from;
u16 window;
unsigned long stale_limit;
/* Reception */
u16 rcv_nxt;
u32 rcv_unacked;
struct sk_buff_head deferdq;
struct sk_buff_head *inputq;
struct sk_buff_head *namedq;
/* Congestion handling */
struct sk_buff_head wakeupq;
/* Fragmentation/reassembly */
struct sk_buff *reasm_buf;
/* Broadcast */
u16 ackers;
u16 acked;
struct tipc_link *bc_rcvlink;
struct tipc_link *bc_sndlink;
u8 nack_state;
bool bc_peer_is_up;
/* Statistics */
struct tipc_stats stats;
};
/*
* Error message prefixes
*/
static const char *link_co_err = "Link tunneling error, ";
static const char *link_rst_msg = "Resetting link ";
/* Send states for broadcast NACKs
*/
enum {
BC_NACK_SND_CONDITIONAL,
BC_NACK_SND_UNCONDITIONAL,
BC_NACK_SND_SUPPRESS,
};
#define TIPC_BC_RETR_LIM msecs_to_jiffies(10) /* [ms] */
tipc: reduce duplicate packets for unicast traffic For unicast transmission, the current NACK sending althorithm is over- active that forces the sending side to retransmit a packet that is not really lost but just arrived at the receiving side with some delay, or even retransmit same packets that have already been retransmitted before. As a result, many duplicates are observed also under normal condition, ie. without packet loss. One example case is: node1 transmits 1 2 3 4 10 5 6 7 8 9, when node2 receives packet #10, it puts into the deferdq. When the packet #5 comes it sends NACK with gap [6 - 9]. However, shortly after that, when packet #6 arrives, it pulls out packet #10 from the deferfq, but it is still out of order, so it makes another NACK with gap [7 - 9] and so on ... Finally, node1 has to retransmit the packets 5 6 7 8 9 a number of times, but in fact all the packets are not lost at all, so duplicates! This commit reduces duplicates by changing the condition to send NACK, also restricting the retransmissions on individual packets via a timer of about 1ms. However, it also needs to say that too tricky condition for NACKs or too long timeout value for retransmissions will result in performance reducing! The criterias in this commit are found to be effective for both the requirements to reduce duplicates but not affect performance. The tipc_link_rcv() is also improved to only dequeue skb from the link deferdq if it is expected (ie. its seqno <= rcv_nxt). Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:52 +07:00
#define TIPC_UC_RETR_TIME (jiffies + msecs_to_jiffies(1))
/*
* Interval between NACKs when packets arrive out of order
*/
#define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
/* Link FSM states:
*/
enum {
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
LINK_ESTABLISHED = 0xe,
LINK_ESTABLISHING = 0xe << 4,
LINK_RESET = 0x1 << 8,
LINK_RESETTING = 0x2 << 12,
LINK_PEER_RESET = 0xd << 16,
LINK_FAILINGOVER = 0xf << 20,
LINK_SYNCHING = 0xc << 24
};
/* Link FSM state checking routines
*/
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
static int link_is_up(struct tipc_link *l)
{
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
}
static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
struct sk_buff_head *xmitq);
static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
bool probe_reply, u16 rcvgap,
int tolerance, int priority,
struct sk_buff_head *xmitq);
static void link_print(struct tipc_link *l, const char *str);
static int tipc_link_build_nack_msg(struct tipc_link *l,
struct sk_buff_head *xmitq);
static void tipc_link_build_bc_init_msg(struct tipc_link *l,
struct sk_buff_head *xmitq);
static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
static u16 tipc_build_gap_ack_blks(struct tipc_link *l, void *data);
static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,
struct tipc_gap_ack_blks *ga,
struct sk_buff_head *xmitq);
/*
* Simple non-static link routines (i.e. referenced outside this file)
*/
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
bool tipc_link_is_up(struct tipc_link *l)
{
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
return link_is_up(l);
}
bool tipc_link_peer_is_down(struct tipc_link *l)
{
return l->state == LINK_PEER_RESET;
}
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
bool tipc_link_is_reset(struct tipc_link *l)
{
return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
}
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
bool tipc_link_is_establishing(struct tipc_link *l)
{
return l->state == LINK_ESTABLISHING;
}
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
bool tipc_link_is_synching(struct tipc_link *l)
{
return l->state == LINK_SYNCHING;
}
bool tipc_link_is_failingover(struct tipc_link *l)
{
return l->state == LINK_FAILINGOVER;
}
bool tipc_link_is_blocked(struct tipc_link *l)
{
return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
}
static bool link_is_bc_sndlink(struct tipc_link *l)
{
return !l->bc_sndlink;
}
static bool link_is_bc_rcvlink(struct tipc_link *l)
{
return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
}
void tipc_link_set_active(struct tipc_link *l, bool active)
{
l->active = active;
}
u32 tipc_link_id(struct tipc_link *l)
{
return l->peer_bearer_id << 16 | l->bearer_id;
}
int tipc_link_window(struct tipc_link *l)
{
return l->window;
}
int tipc_link_prio(struct tipc_link *l)
{
return l->priority;
}
unsigned long tipc_link_tolerance(struct tipc_link *l)
{
return l->tolerance;
}
struct sk_buff_head *tipc_link_inputq(struct tipc_link *l)
{
return l->inputq;
}
char tipc_link_plane(struct tipc_link *l)
{
return l->net_plane;
}
void tipc_link_update_caps(struct tipc_link *l, u16 capabilities)
{
l->peer_caps = capabilities;
}
void tipc_link_add_bc_peer(struct tipc_link *snd_l,
struct tipc_link *uc_l,
struct sk_buff_head *xmitq)
{
struct tipc_link *rcv_l = uc_l->bc_rcvlink;
snd_l->ackers++;
rcv_l->acked = snd_l->snd_nxt - 1;
snd_l->state = LINK_ESTABLISHED;
tipc_link_build_bc_init_msg(uc_l, xmitq);
}
void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
struct tipc_link *rcv_l,
struct sk_buff_head *xmitq)
{
u16 ack = snd_l->snd_nxt - 1;
snd_l->ackers--;
tipc: ensure correct broadcast send buffer release when peer is lost After a new receiver peer has been added to the broadcast transmission link, we allow immediate transmission of new broadcast packets, trusting that the new peer will not accept the packets until it has received the previously sent unicast broadcast initialiation message. In the same way, the sender must not accept any acknowledges until it has itself received the broadcast initialization from the peer, as well as confirmation of the reception of its own initialization message. Furthermore, when a receiver peer goes down, the sender has to produce the missing acknowledges from the lost peer locally, in order ensure correct release of the buffers that were expected to be acknowledged by the said peer. In a highly stressed system we have observed that contact with a peer may come up and be lost before the above mentioned broadcast initial- ization and confirmation have been received. This leads to the locally produced acknowledges being rejected, and the non-acknowledged buffers to linger in the broadcast link transmission queue until it fills up and the link goes into permanent congestion. In this commit, we remedy this by temporarily setting the corresponding broadcast receive link state to ESTABLISHED and the 'bc_peer_is_up' state to true before we issue the local acknowledges. This ensures that those acknowledges will always be accepted. The mentioned state values are restored immediately afterwards when the link is reset. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-12 03:08:36 +07:00
rcv_l->bc_peer_is_up = true;
rcv_l->state = LINK_ESTABLISHED;
tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_link_reset(rcv_l, TIPC_DUMP_ALL, "bclink removed!");
tipc_link_reset(rcv_l);
rcv_l->state = LINK_RESET;
if (!snd_l->ackers) {
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_link_reset(snd_l, TIPC_DUMP_ALL, "zero ackers!");
tipc_link_reset(snd_l);
snd_l->state = LINK_RESET;
__skb_queue_purge(xmitq);
}
}
int tipc_link_bc_peers(struct tipc_link *l)
{
return l->ackers;
}
static u16 link_bc_rcv_gap(struct tipc_link *l)
{
struct sk_buff *skb = skb_peek(&l->deferdq);
u16 gap = 0;
if (more(l->snd_nxt, l->rcv_nxt))
gap = l->snd_nxt - l->rcv_nxt;
if (skb)
gap = buf_seqno(skb) - l->rcv_nxt;
return gap;
}
void tipc_link_set_mtu(struct tipc_link *l, int mtu)
{
l->mtu = mtu;
}
int tipc_link_mtu(struct tipc_link *l)
{
return l->mtu;
}
u16 tipc_link_rcv_nxt(struct tipc_link *l)
{
return l->rcv_nxt;
}
u16 tipc_link_acked(struct tipc_link *l)
{
return l->acked;
}
char *tipc_link_name(struct tipc_link *l)
{
return l->name;
}
u32 tipc_link_state(struct tipc_link *l)
{
return l->state;
}
/**
* tipc_link_create - create a new link
* @n: pointer to associated node
* @if_name: associated interface name
* @bearer_id: id (index) of associated bearer
* @tolerance: link tolerance to be used by link
* @net_plane: network plane (A,B,c..) this link belongs to
* @mtu: mtu to be advertised by link
* @priority: priority to be used by link
* @window: send window to be used by link
* @session: session to be used by link
* @ownnode: identity of own node
* @peer: node id of peer node
* @peer_caps: bitmap describing peer node capabilities
* @bc_sndlink: the namespace global link used for broadcast sending
* @bc_rcvlink: the peer specific link used for broadcast reception
* @inputq: queue to put messages ready for delivery
* @namedq: queue to put binding table update messages ready for delivery
* @link: return value, pointer to put the created link
*
* Returns true if link was created, otherwise false
*/
bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
int tolerance, char net_plane, u32 mtu, int priority,
tipc: handle collisions of 32-bit node address hash values When a 32-bit node address is generated from a 128-bit identifier, there is a risk of collisions which must be discovered and handled. We do this as follows: - We don't apply the generated address immediately to the node, but do instead initiate a 1 sec trial period to allow other cluster members to discover and handle such collisions. - During the trial period the node periodically sends out a new type of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast, to all the other nodes in the cluster. - When a node is receiving such a message, it must check that the presented 32-bit identifier either is unused, or was used by the very same peer in a previous session. In both cases it accepts the request by not responding to it. - If it finds that the same node has been up before using a different address, it responds with a DSC_TRIAL_FAIL_MSG containing that address. - If it finds that the address has already been taken by some other node, it generates a new, unused address and returns it to the requester. - During the trial period the requesting node must always be prepared to accept a failure message, i.e., a message where a peer suggests a different (or equal) address to the one tried. In those cases it must apply the suggested value as trial address and restart the trial period. This algorithm ensures that in the vast majority of cases a node will have the same address before and after a reboot. If a legacy user configures the address explicitly, there will be no trial period and messages, so this protocol addition is completely backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23 02:42:51 +07:00
int window, u32 session, u32 self,
u32 peer, u8 *peer_id, u16 peer_caps,
struct tipc_link *bc_sndlink,
struct tipc_link *bc_rcvlink,
struct sk_buff_head *inputq,
struct sk_buff_head *namedq,
struct tipc_link **link)
{
tipc: handle collisions of 32-bit node address hash values When a 32-bit node address is generated from a 128-bit identifier, there is a risk of collisions which must be discovered and handled. We do this as follows: - We don't apply the generated address immediately to the node, but do instead initiate a 1 sec trial period to allow other cluster members to discover and handle such collisions. - During the trial period the node periodically sends out a new type of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast, to all the other nodes in the cluster. - When a node is receiving such a message, it must check that the presented 32-bit identifier either is unused, or was used by the very same peer in a previous session. In both cases it accepts the request by not responding to it. - If it finds that the same node has been up before using a different address, it responds with a DSC_TRIAL_FAIL_MSG containing that address. - If it finds that the address has already been taken by some other node, it generates a new, unused address and returns it to the requester. - During the trial period the requesting node must always be prepared to accept a failure message, i.e., a message where a peer suggests a different (or equal) address to the one tried. In those cases it must apply the suggested value as trial address and restart the trial period. This algorithm ensures that in the vast majority of cases a node will have the same address before and after a reboot. If a legacy user configures the address explicitly, there will be no trial period and messages, so this protocol addition is completely backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23 02:42:51 +07:00
char peer_str[NODE_ID_STR_LEN] = {0,};
char self_str[NODE_ID_STR_LEN] = {0,};
struct tipc_link *l;
l = kzalloc(sizeof(*l), GFP_ATOMIC);
if (!l)
return false;
*link = l;
l->session = session;
tipc: handle collisions of 32-bit node address hash values When a 32-bit node address is generated from a 128-bit identifier, there is a risk of collisions which must be discovered and handled. We do this as follows: - We don't apply the generated address immediately to the node, but do instead initiate a 1 sec trial period to allow other cluster members to discover and handle such collisions. - During the trial period the node periodically sends out a new type of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast, to all the other nodes in the cluster. - When a node is receiving such a message, it must check that the presented 32-bit identifier either is unused, or was used by the very same peer in a previous session. In both cases it accepts the request by not responding to it. - If it finds that the same node has been up before using a different address, it responds with a DSC_TRIAL_FAIL_MSG containing that address. - If it finds that the address has already been taken by some other node, it generates a new, unused address and returns it to the requester. - During the trial period the requesting node must always be prepared to accept a failure message, i.e., a message where a peer suggests a different (or equal) address to the one tried. In those cases it must apply the suggested value as trial address and restart the trial period. This algorithm ensures that in the vast majority of cases a node will have the same address before and after a reboot. If a legacy user configures the address explicitly, there will be no trial period and messages, so this protocol addition is completely backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23 02:42:51 +07:00
/* Set link name for unicast links only */
if (peer_id) {
tipc_nodeid2string(self_str, tipc_own_id(net));
if (strlen(self_str) > 16)
sprintf(self_str, "%x", self);
tipc_nodeid2string(peer_str, peer_id);
if (strlen(peer_str) > 16)
sprintf(peer_str, "%x", peer);
}
/* Peer i/f name will be completed by reset/activate message */
snprintf(l->name, sizeof(l->name), "%s:%s-%s:unknown",
self_str, if_name, peer_str);
tipc: handle collisions of 32-bit node address hash values When a 32-bit node address is generated from a 128-bit identifier, there is a risk of collisions which must be discovered and handled. We do this as follows: - We don't apply the generated address immediately to the node, but do instead initiate a 1 sec trial period to allow other cluster members to discover and handle such collisions. - During the trial period the node periodically sends out a new type of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast, to all the other nodes in the cluster. - When a node is receiving such a message, it must check that the presented 32-bit identifier either is unused, or was used by the very same peer in a previous session. In both cases it accepts the request by not responding to it. - If it finds that the same node has been up before using a different address, it responds with a DSC_TRIAL_FAIL_MSG containing that address. - If it finds that the address has already been taken by some other node, it generates a new, unused address and returns it to the requester. - During the trial period the requesting node must always be prepared to accept a failure message, i.e., a message where a peer suggests a different (or equal) address to the one tried. In those cases it must apply the suggested value as trial address and restart the trial period. This algorithm ensures that in the vast majority of cases a node will have the same address before and after a reboot. If a legacy user configures the address explicitly, there will be no trial period and messages, so this protocol addition is completely backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23 02:42:51 +07:00
strcpy(l->if_name, if_name);
l->addr = peer;
l->peer_caps = peer_caps;
l->net = net;
l->in_session = false;
l->bearer_id = bearer_id;
l->tolerance = tolerance;
if (bc_rcvlink)
bc_rcvlink->tolerance = tolerance;
l->net_plane = net_plane;
l->advertised_mtu = mtu;
l->mtu = mtu;
l->priority = priority;
tipc_link_set_queue_limits(l, window);
l->ackers = 1;
l->bc_sndlink = bc_sndlink;
l->bc_rcvlink = bc_rcvlink;
l->inputq = inputq;
l->namedq = namedq;
l->state = LINK_RESETTING;
__skb_queue_head_init(&l->transmq);
__skb_queue_head_init(&l->backlogq);
__skb_queue_head_init(&l->deferdq);
__skb_queue_head_init(&l->failover_deferdq);
skb_queue_head_init(&l->wakeupq);
skb_queue_head_init(l->inputq);
return true;
}
/**
* tipc_link_bc_create - create new link to be used for broadcast
* @n: pointer to associated node
* @mtu: mtu to be used initially if no peers
* @window: send window to be used
* @inputq: queue to put messages ready for delivery
* @namedq: queue to put binding table update messages ready for delivery
* @link: return value, pointer to put the created link
*
* Returns true if link was created, otherwise false
*/
bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
int mtu, int window, u16 peer_caps,
struct sk_buff_head *inputq,
struct sk_buff_head *namedq,
struct tipc_link *bc_sndlink,
struct tipc_link **link)
{
struct tipc_link *l;
if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
tipc: handle collisions of 32-bit node address hash values When a 32-bit node address is generated from a 128-bit identifier, there is a risk of collisions which must be discovered and handled. We do this as follows: - We don't apply the generated address immediately to the node, but do instead initiate a 1 sec trial period to allow other cluster members to discover and handle such collisions. - During the trial period the node periodically sends out a new type of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast, to all the other nodes in the cluster. - When a node is receiving such a message, it must check that the presented 32-bit identifier either is unused, or was used by the very same peer in a previous session. In both cases it accepts the request by not responding to it. - If it finds that the same node has been up before using a different address, it responds with a DSC_TRIAL_FAIL_MSG containing that address. - If it finds that the address has already been taken by some other node, it generates a new, unused address and returns it to the requester. - During the trial period the requesting node must always be prepared to accept a failure message, i.e., a message where a peer suggests a different (or equal) address to the one tried. In those cases it must apply the suggested value as trial address and restart the trial period. This algorithm ensures that in the vast majority of cases a node will have the same address before and after a reboot. If a legacy user configures the address explicitly, there will be no trial period and messages, so this protocol addition is completely backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-23 02:42:51 +07:00
0, ownnode, peer, NULL, peer_caps, bc_sndlink,
NULL, inputq, namedq, link))
return false;
l = *link;
strcpy(l->name, tipc_bclink_name);
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_link_reset(l, TIPC_DUMP_ALL, "bclink created!");
tipc_link_reset(l);
l->state = LINK_RESET;
l->ackers = 0;
l->bc_rcvlink = l;
/* Broadcast send link is always up */
if (link_is_bc_sndlink(l))
l->state = LINK_ESTABLISHED;
/* Disable replicast if even a single peer doesn't support it */
if (link_is_bc_rcvlink(l) && !(peer_caps & TIPC_BCAST_RCAST))
tipc_bcast_disable_rcast(net);
return true;
}
/**
* tipc_link_fsm_evt - link finite state machine
* @l: pointer to link
* @evt: state machine event to be processed
*/
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
int tipc_link_fsm_evt(struct tipc_link *l, int evt)
{
int rc = 0;
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
int old_state = l->state;
switch (l->state) {
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_RESETTING:
switch (evt) {
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_PEER_RESET_EVT:
l->state = LINK_PEER_RESET;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_RESET_EVT:
l->state = LINK_RESET;
break;
case LINK_FAILURE_EVT:
case LINK_FAILOVER_BEGIN_EVT:
case LINK_ESTABLISH_EVT:
case LINK_FAILOVER_END_EVT:
case LINK_SYNCH_BEGIN_EVT:
case LINK_SYNCH_END_EVT:
default:
goto illegal_evt;
}
break;
case LINK_RESET:
switch (evt) {
case LINK_PEER_RESET_EVT:
l->state = LINK_ESTABLISHING;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_FAILOVER_BEGIN_EVT:
l->state = LINK_FAILINGOVER;
case LINK_FAILURE_EVT:
case LINK_RESET_EVT:
case LINK_ESTABLISH_EVT:
case LINK_FAILOVER_END_EVT:
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_SYNCH_BEGIN_EVT:
case LINK_SYNCH_END_EVT:
default:
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
goto illegal_evt;
}
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_PEER_RESET:
switch (evt) {
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_RESET_EVT:
l->state = LINK_ESTABLISHING;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_PEER_RESET_EVT:
case LINK_ESTABLISH_EVT:
case LINK_FAILURE_EVT:
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_SYNCH_BEGIN_EVT:
case LINK_SYNCH_END_EVT:
case LINK_FAILOVER_BEGIN_EVT:
case LINK_FAILOVER_END_EVT:
default:
goto illegal_evt;
}
break;
case LINK_FAILINGOVER:
switch (evt) {
case LINK_FAILOVER_END_EVT:
l->state = LINK_RESET;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_PEER_RESET_EVT:
case LINK_RESET_EVT:
case LINK_ESTABLISH_EVT:
case LINK_FAILURE_EVT:
break;
case LINK_FAILOVER_BEGIN_EVT:
case LINK_SYNCH_BEGIN_EVT:
case LINK_SYNCH_END_EVT:
default:
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
goto illegal_evt;
}
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_ESTABLISHING:
switch (evt) {
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_ESTABLISH_EVT:
l->state = LINK_ESTABLISHED;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_FAILOVER_BEGIN_EVT:
l->state = LINK_FAILINGOVER;
break;
case LINK_RESET_EVT:
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
l->state = LINK_RESET;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_FAILURE_EVT:
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
case LINK_PEER_RESET_EVT:
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_SYNCH_BEGIN_EVT:
case LINK_FAILOVER_END_EVT:
break;
case LINK_SYNCH_END_EVT:
default:
goto illegal_evt;
}
break;
case LINK_ESTABLISHED:
switch (evt) {
case LINK_PEER_RESET_EVT:
l->state = LINK_PEER_RESET;
rc |= TIPC_LINK_DOWN_EVT;
break;
case LINK_FAILURE_EVT:
l->state = LINK_RESETTING;
rc |= TIPC_LINK_DOWN_EVT;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_RESET_EVT:
l->state = LINK_RESET;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_ESTABLISH_EVT:
case LINK_SYNCH_END_EVT:
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_SYNCH_BEGIN_EVT:
l->state = LINK_SYNCHING;
break;
case LINK_FAILOVER_BEGIN_EVT:
case LINK_FAILOVER_END_EVT:
default:
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
goto illegal_evt;
}
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_SYNCHING:
switch (evt) {
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_PEER_RESET_EVT:
l->state = LINK_PEER_RESET;
rc |= TIPC_LINK_DOWN_EVT;
break;
case LINK_FAILURE_EVT:
l->state = LINK_RESETTING;
rc |= TIPC_LINK_DOWN_EVT;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_RESET_EVT:
l->state = LINK_RESET;
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_ESTABLISH_EVT:
case LINK_SYNCH_BEGIN_EVT:
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_SYNCH_END_EVT:
l->state = LINK_ESTABLISHED;
break;
case LINK_FAILOVER_BEGIN_EVT:
case LINK_FAILOVER_END_EVT:
default:
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
goto illegal_evt;
}
break;
default:
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
}
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_link_fsm(l->name, old_state, l->state, evt);
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
return rc;
illegal_evt:
pr_err("Illegal FSM event %x in state %x on link %s\n",
evt, l->state, l->name);
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_link_fsm(l->name, old_state, l->state, evt);
return rc;
}
/* link_profile_stats - update statistical profiling of traffic
*/
static void link_profile_stats(struct tipc_link *l)
{
struct sk_buff *skb;
struct tipc_msg *msg;
int length;
/* Update counters used in statistical profiling of send traffic */
l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
l->stats.queue_sz_counts++;
skb = skb_peek(&l->transmq);
if (!skb)
return;
msg = buf_msg(skb);
length = msg_size(msg);
if (msg_user(msg) == MSG_FRAGMENTER) {
if (msg_type(msg) != FIRST_FRAGMENT)
return;
length = msg_size(msg_get_wrapped(msg));
}
l->stats.msg_lengths_total += length;
l->stats.msg_length_counts++;
if (length <= 64)
l->stats.msg_length_profile[0]++;
else if (length <= 256)
l->stats.msg_length_profile[1]++;
else if (length <= 1024)
l->stats.msg_length_profile[2]++;
else if (length <= 4096)
l->stats.msg_length_profile[3]++;
else if (length <= 16384)
l->stats.msg_length_profile[4]++;
else if (length <= 32768)
l->stats.msg_length_profile[5]++;
else
l->stats.msg_length_profile[6]++;
}
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
/**
* tipc_link_too_silent - check if link is "too silent"
* @l: tipc link to be checked
*
* Returns true if the link 'silent_intv_cnt' is about to reach the
* 'abort_limit' value, otherwise false
*/
bool tipc_link_too_silent(struct tipc_link *l)
{
return (l->silent_intv_cnt + 2 > l->abort_limit);
}
/* tipc_link_timeout - perform periodic task as instructed from node timeout
*/
int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
{
int mtyp = 0;
int rc = 0;
bool state = false;
bool probe = false;
bool setup = false;
u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
u16 bc_acked = l->bc_rcvlink->acked;
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
struct tipc_mon_state *mstate = &l->mon_state;
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_link_timeout(l, TIPC_DUMP_NONE, " ");
trace_tipc_link_too_silent(l, TIPC_DUMP_ALL, " ");
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
switch (l->state) {
case LINK_ESTABLISHED:
case LINK_SYNCHING:
mtyp = STATE_MSG;
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
link_profile_stats(l);
tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id);
if (mstate->reset || (l->silent_intv_cnt > l->abort_limit))
return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
state = bc_acked != bc_snt;
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
state |= l->bc_rcvlink->rcv_unacked;
state |= l->rcv_unacked;
state |= !skb_queue_empty(&l->transmq);
state |= !skb_queue_empty(&l->deferdq);
probe = mstate->probing;
probe |= l->silent_intv_cnt;
if (probe || mstate->monitoring)
l->silent_intv_cnt++;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
break;
case LINK_RESET:
setup = l->rst_cnt++ <= 4;
setup |= !(l->rst_cnt % 16);
mtyp = RESET_MSG;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
break;
case LINK_ESTABLISHING:
setup = true;
mtyp = ACTIVATE_MSG;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
break;
case LINK_PEER_RESET:
case LINK_RESETTING:
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case LINK_FAILINGOVER:
break;
default:
break;
}
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
if (state || probe || setup)
tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, 0, xmitq);
return rc;
}
/**
* link_schedule_user - schedule a message sender for wakeup after congestion
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
* @l: congested link
* @hdr: header of message that is being sent
* Create pseudo msg to send back to user when congestion abates
*/
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
static int link_schedule_user(struct tipc_link *l, struct tipc_msg *hdr)
{
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
u32 dnode = tipc_own_addr(l->net);
u32 dport = msg_origport(hdr);
struct sk_buff *skb;
/* Create and schedule wakeup pseudo message */
skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
dnode, l->addr, dport, 0, 0);
if (!skb)
return -ENOBUFS;
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
msg_set_dest_droppable(buf_msg(skb), true);
TIPC_SKB_CB(skb)->chain_imp = msg_importance(hdr);
skb_queue_tail(&l->wakeupq, skb);
l->stats.link_congs++;
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_link_conges(l, TIPC_DUMP_ALL, "wakeup scheduled!");
return -ELINKCONG;
}
/**
* link_prepare_wakeup - prepare users for wakeup after congestion
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
* @l: congested link
* Wake up a number of waiting users, as permitted by available space
* in the send queue
*/
static void link_prepare_wakeup(struct tipc_link *l)
{
struct sk_buff *skb, *tmp;
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
int imp, i = 0;
skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
imp = TIPC_SKB_CB(skb)->chain_imp;
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
if (l->backlog[imp].len < l->backlog[imp].limit) {
skb_unlink(skb, &l->wakeupq);
skb_queue_tail(l->inputq, skb);
} else if (i++ > 10) {
break;
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
}
}
}
void tipc_link_reset(struct tipc_link *l)
{
tipc: eliminate possible recursive locking detected by LOCKDEP When booting kernel with LOCKDEP option, below warning info was found: WARNING: possible recursive locking detected 4.19.0-rc7+ #14 Not tainted -------------------------------------------- swapper/0/1 is trying to acquire lock: 00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] 00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850 but task is already holding lock: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&list->lock)->rlock#4); lock(&(&list->lock)->rlock#4); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by swapper/0/1: #0: 00000000f7539d34 (pernet_ops_rwsem){+.+.}, at: register_pernet_subsys+0x19/0x40 net/core/net_namespace.c:1051 #1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] #1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849 stack backtrace: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc7+ #14 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1af/0x295 lib/dump_stack.c:113 print_deadlock_bug kernel/locking/lockdep.c:1759 [inline] check_deadlock kernel/locking/lockdep.c:1803 [inline] validate_chain kernel/locking/lockdep.c:2399 [inline] __lock_acquire+0xf1e/0x3c60 kernel/locking/lockdep.c:3411 lock_acquire+0x1db/0x520 kernel/locking/lockdep.c:3900 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850 tipc_link_bc_create+0xb5/0x1f0 net/tipc/link.c:526 tipc_bcast_init+0x59b/0xab0 net/tipc/bcast.c:521 tipc_init_net+0x472/0x610 net/tipc/core.c:82 ops_init+0xf7/0x520 net/core/net_namespace.c:129 __register_pernet_operations net/core/net_namespace.c:940 [inline] register_pernet_operations+0x453/0xac0 net/core/net_namespace.c:1011 register_pernet_subsys+0x28/0x40 net/core/net_namespace.c:1052 tipc_init+0x83/0x104 net/tipc/core.c:140 do_one_initcall+0x109/0x70a init/main.c:885 do_initcall_level init/main.c:953 [inline] do_initcalls init/main.c:961 [inline] do_basic_setup init/main.c:979 [inline] kernel_init_freeable+0x4bd/0x57f init/main.c:1144 kernel_init+0x13/0x180 init/main.c:1063 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 The reason why the noise above was complained by LOCKDEP is because we nested to hold l->wakeupq.lock and l->inputq->lock in tipc_link_reset function. In fact it's unnecessary to move skb buffer from l->wakeupq queue to l->inputq queue while holding the two locks at the same time. Instead, we can move skb buffers in l->wakeupq queue to a temporary list first and then move the buffers of the temporary list to l->inputq queue, which is also safe for us. Fixes: 3f32d0be6c16 ("tipc: lock wakeup & inputq at tipc_link_reset()") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-11 18:57:56 +07:00
struct sk_buff_head list;
__skb_queue_head_init(&list);
l->in_session = false;
tipc: fix link established but not in session According to the link FSM, when a link endpoint got RESET_MSG (- a traditional one without the stopping bit) from its peer, it moves to PEER_RESET state and raises a LINK_DOWN event which then resets the link itself. Its state will become ESTABLISHING after the reset event and the link will be re-established soon after this endpoint starts to send ACTIVATE_MSG to the peer. There is no problem with this mechanism, however the link resetting has cleared the link 'in_session' flag (along with the other important link data such as: the link 'mtu') that was correctly set up at the 1st step (i.e. when this endpoint received the peer RESET_MSG). As a result, the link will become ESTABLISHED, but the 'in_session' flag is not set, and all STATE_MSG from its peer will be dropped at the link_validate_msg(). It means the link not synced and will sooner or later face a failure. Since the link reset action is obviously needed for a new link session (this is also true in the other situations), the problem here is that the link is re-established a bit too early when the link endpoints are not really in-sync yet. The commit forces a resync as already done in the previous commit 91986ee166cf ("tipc: fix link session and re-establish issues") by simply varying the link 'peer_session' value at the link_reset(). Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-16 10:48:07 +07:00
/* Force re-synch of peer session number before establishing */
l->peer_session--;
l->session++;
l->mtu = l->advertised_mtu;
tipc: eliminate possible recursive locking detected by LOCKDEP When booting kernel with LOCKDEP option, below warning info was found: WARNING: possible recursive locking detected 4.19.0-rc7+ #14 Not tainted -------------------------------------------- swapper/0/1 is trying to acquire lock: 00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] 00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850 but task is already holding lock: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&list->lock)->rlock#4); lock(&(&list->lock)->rlock#4); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by swapper/0/1: #0: 00000000f7539d34 (pernet_ops_rwsem){+.+.}, at: register_pernet_subsys+0x19/0x40 net/core/net_namespace.c:1051 #1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] #1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849 stack backtrace: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc7+ #14 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1af/0x295 lib/dump_stack.c:113 print_deadlock_bug kernel/locking/lockdep.c:1759 [inline] check_deadlock kernel/locking/lockdep.c:1803 [inline] validate_chain kernel/locking/lockdep.c:2399 [inline] __lock_acquire+0xf1e/0x3c60 kernel/locking/lockdep.c:3411 lock_acquire+0x1db/0x520 kernel/locking/lockdep.c:3900 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850 tipc_link_bc_create+0xb5/0x1f0 net/tipc/link.c:526 tipc_bcast_init+0x59b/0xab0 net/tipc/bcast.c:521 tipc_init_net+0x472/0x610 net/tipc/core.c:82 ops_init+0xf7/0x520 net/core/net_namespace.c:129 __register_pernet_operations net/core/net_namespace.c:940 [inline] register_pernet_operations+0x453/0xac0 net/core/net_namespace.c:1011 register_pernet_subsys+0x28/0x40 net/core/net_namespace.c:1052 tipc_init+0x83/0x104 net/tipc/core.c:140 do_one_initcall+0x109/0x70a init/main.c:885 do_initcall_level init/main.c:953 [inline] do_initcalls init/main.c:961 [inline] do_basic_setup init/main.c:979 [inline] kernel_init_freeable+0x4bd/0x57f init/main.c:1144 kernel_init+0x13/0x180 init/main.c:1063 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 The reason why the noise above was complained by LOCKDEP is because we nested to hold l->wakeupq.lock and l->inputq->lock in tipc_link_reset function. In fact it's unnecessary to move skb buffer from l->wakeupq queue to l->inputq queue while holding the two locks at the same time. Instead, we can move skb buffers in l->wakeupq queue to a temporary list first and then move the buffers of the temporary list to l->inputq queue, which is also safe for us. Fixes: 3f32d0be6c16 ("tipc: lock wakeup & inputq at tipc_link_reset()") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-11 18:57:56 +07:00
spin_lock_bh(&l->wakeupq.lock);
tipc: eliminate possible recursive locking detected by LOCKDEP When booting kernel with LOCKDEP option, below warning info was found: WARNING: possible recursive locking detected 4.19.0-rc7+ #14 Not tainted -------------------------------------------- swapper/0/1 is trying to acquire lock: 00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] 00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850 but task is already holding lock: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&list->lock)->rlock#4); lock(&(&list->lock)->rlock#4); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by swapper/0/1: #0: 00000000f7539d34 (pernet_ops_rwsem){+.+.}, at: register_pernet_subsys+0x19/0x40 net/core/net_namespace.c:1051 #1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] #1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849 stack backtrace: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc7+ #14 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1af/0x295 lib/dump_stack.c:113 print_deadlock_bug kernel/locking/lockdep.c:1759 [inline] check_deadlock kernel/locking/lockdep.c:1803 [inline] validate_chain kernel/locking/lockdep.c:2399 [inline] __lock_acquire+0xf1e/0x3c60 kernel/locking/lockdep.c:3411 lock_acquire+0x1db/0x520 kernel/locking/lockdep.c:3900 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850 tipc_link_bc_create+0xb5/0x1f0 net/tipc/link.c:526 tipc_bcast_init+0x59b/0xab0 net/tipc/bcast.c:521 tipc_init_net+0x472/0x610 net/tipc/core.c:82 ops_init+0xf7/0x520 net/core/net_namespace.c:129 __register_pernet_operations net/core/net_namespace.c:940 [inline] register_pernet_operations+0x453/0xac0 net/core/net_namespace.c:1011 register_pernet_subsys+0x28/0x40 net/core/net_namespace.c:1052 tipc_init+0x83/0x104 net/tipc/core.c:140 do_one_initcall+0x109/0x70a init/main.c:885 do_initcall_level init/main.c:953 [inline] do_initcalls init/main.c:961 [inline] do_basic_setup init/main.c:979 [inline] kernel_init_freeable+0x4bd/0x57f init/main.c:1144 kernel_init+0x13/0x180 init/main.c:1063 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 The reason why the noise above was complained by LOCKDEP is because we nested to hold l->wakeupq.lock and l->inputq->lock in tipc_link_reset function. In fact it's unnecessary to move skb buffer from l->wakeupq queue to l->inputq queue while holding the two locks at the same time. Instead, we can move skb buffers in l->wakeupq queue to a temporary list first and then move the buffers of the temporary list to l->inputq queue, which is also safe for us. Fixes: 3f32d0be6c16 ("tipc: lock wakeup & inputq at tipc_link_reset()") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-11 18:57:56 +07:00
skb_queue_splice_init(&l->wakeupq, &list);
spin_unlock_bh(&l->wakeupq.lock);
spin_lock_bh(&l->inputq->lock);
tipc: eliminate possible recursive locking detected by LOCKDEP When booting kernel with LOCKDEP option, below warning info was found: WARNING: possible recursive locking detected 4.19.0-rc7+ #14 Not tainted -------------------------------------------- swapper/0/1 is trying to acquire lock: 00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] 00000000dcfc0fc8 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850 but task is already holding lock: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&list->lock)->rlock#4); lock(&(&list->lock)->rlock#4); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by swapper/0/1: #0: 00000000f7539d34 (pernet_ops_rwsem){+.+.}, at: register_pernet_subsys+0x19/0x40 net/core/net_namespace.c:1051 #1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: spin_lock_bh include/linux/spinlock.h:334 [inline] #1: 00000000cbb9b036 (&(&list->lock)->rlock#4){+...}, at: tipc_link_reset+0xfa/0xdf0 net/tipc/link.c:849 stack backtrace: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc7+ #14 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1af/0x295 lib/dump_stack.c:113 print_deadlock_bug kernel/locking/lockdep.c:1759 [inline] check_deadlock kernel/locking/lockdep.c:1803 [inline] validate_chain kernel/locking/lockdep.c:2399 [inline] __lock_acquire+0xf1e/0x3c60 kernel/locking/lockdep.c:3411 lock_acquire+0x1db/0x520 kernel/locking/lockdep.c:3900 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 spin_lock_bh include/linux/spinlock.h:334 [inline] tipc_link_reset+0x125/0xdf0 net/tipc/link.c:850 tipc_link_bc_create+0xb5/0x1f0 net/tipc/link.c:526 tipc_bcast_init+0x59b/0xab0 net/tipc/bcast.c:521 tipc_init_net+0x472/0x610 net/tipc/core.c:82 ops_init+0xf7/0x520 net/core/net_namespace.c:129 __register_pernet_operations net/core/net_namespace.c:940 [inline] register_pernet_operations+0x453/0xac0 net/core/net_namespace.c:1011 register_pernet_subsys+0x28/0x40 net/core/net_namespace.c:1052 tipc_init+0x83/0x104 net/tipc/core.c:140 do_one_initcall+0x109/0x70a init/main.c:885 do_initcall_level init/main.c:953 [inline] do_initcalls init/main.c:961 [inline] do_basic_setup init/main.c:979 [inline] kernel_init_freeable+0x4bd/0x57f init/main.c:1144 kernel_init+0x13/0x180 init/main.c:1063 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 The reason why the noise above was complained by LOCKDEP is because we nested to hold l->wakeupq.lock and l->inputq->lock in tipc_link_reset function. In fact it's unnecessary to move skb buffer from l->wakeupq queue to l->inputq queue while holding the two locks at the same time. Instead, we can move skb buffers in l->wakeupq queue to a temporary list first and then move the buffers of the temporary list to l->inputq queue, which is also safe for us. Fixes: 3f32d0be6c16 ("tipc: lock wakeup & inputq at tipc_link_reset()") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-11 18:57:56 +07:00
skb_queue_splice_init(&list, l->inputq);
spin_unlock_bh(&l->inputq->lock);
__skb_queue_purge(&l->transmq);
__skb_queue_purge(&l->deferdq);
__skb_queue_purge(&l->backlogq);
__skb_queue_purge(&l->failover_deferdq);
l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
kfree_skb(l->reasm_buf);
kfree_skb(l->failover_reasm_skb);
l->reasm_buf = NULL;
l->failover_reasm_skb = NULL;
l->rcv_unacked = 0;
l->snd_nxt = 1;
l->rcv_nxt = 1;
l->snd_nxt_state = 1;
l->rcv_nxt_state = 1;
l->acked = 0;
l->silent_intv_cnt = 0;
l->rst_cnt = 0;
l->bc_peer_is_up = false;
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
memset(&l->mon_state, 0, sizeof(l->mon_state));
tipc_link_reset_stats(l);
}
/**
* tipc_link_xmit(): enqueue buffer list according to queue situation
* @link: link to use
* @list: chain of buffers containing message
* @xmitq: returned list of packets to be sent by caller
*
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
* Consumes the buffer chain.
* Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
* Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
*/
int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
struct sk_buff_head *xmitq)
{
struct tipc_msg *hdr = buf_msg(skb_peek(list));
unsigned int maxwin = l->window;
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
int imp = msg_importance(hdr);
unsigned int mtu = l->mtu;
u16 ack = l->rcv_nxt - 1;
u16 seqno = l->snd_nxt;
u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
struct sk_buff_head *transmq = &l->transmq;
struct sk_buff_head *backlogq = &l->backlogq;
struct sk_buff *skb, *_skb, *bskb;
int pkt_cnt = skb_queue_len(list);
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
int rc = 0;
if (unlikely(msg_size(hdr) > mtu)) {
skb_queue_purge(list);
return -EMSGSIZE;
}
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
/* Allow oversubscription of one data msg per source at congestion */
if (unlikely(l->backlog[imp].len >= l->backlog[imp].limit)) {
if (imp == TIPC_SYSTEM_IMPORTANCE) {
pr_warn("%s<%s>, link overflow", link_rst_msg, l->name);
return -ENOBUFS;
}
rc = link_schedule_user(l, hdr);
}
if (pkt_cnt > 1) {
l->stats.sent_fragmented++;
l->stats.sent_fragments += pkt_cnt;
}
/* Prepare each packet for sending, and add to relevant queue: */
while (skb_queue_len(list)) {
skb = skb_peek(list);
hdr = buf_msg(skb);
msg_set_seqno(hdr, seqno);
msg_set_ack(hdr, ack);
msg_set_bcast_ack(hdr, bc_ack);
if (likely(skb_queue_len(transmq) < maxwin)) {
_skb = skb_clone(skb, GFP_ATOMIC);
if (!_skb) {
skb_queue_purge(list);
return -ENOBUFS;
}
__skb_dequeue(list);
__skb_queue_tail(transmq, skb);
/* next retransmit attempt */
if (link_is_bc_sndlink(l))
TIPC_SKB_CB(skb)->nxt_retr =
jiffies + TIPC_BC_RETR_LIM;
__skb_queue_tail(xmitq, _skb);
TIPC_SKB_CB(skb)->ackers = l->ackers;
l->rcv_unacked = 0;
l->stats.sent_pkts++;
seqno++;
continue;
}
if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
kfree_skb(__skb_dequeue(list));
l->stats.sent_bundled++;
continue;
}
if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
kfree_skb(__skb_dequeue(list));
__skb_queue_tail(backlogq, bskb);
l->backlog[msg_importance(buf_msg(bskb))].len++;
l->stats.sent_bundled++;
l->stats.sent_bundles++;
continue;
}
l->backlog[imp].len += skb_queue_len(list);
skb_queue_splice_tail_init(list, backlogq);
}
l->snd_nxt = seqno;
tipc: reduce risk of user starvation during link congestion The socket code currently handles link congestion by either blocking and trying to send again when the congestion has abated, or just returning to the user with -EAGAIN and let him re-try later. This mechanism is prone to starvation, because the wakeup algorithm is non-atomic. During the time the link issues a wakeup signal, until the socket wakes up and re-attempts sending, other senders may have come in between and occupied the free buffer space in the link. This in turn may lead to a socket having to make many send attempts before it is successful. In extremely loaded systems we have observed latency times of several seconds before a low-priority socket is able to send out a message. In this commit, we simplify this mechanism and reduce the risk of the described scenario happening. When a message is attempted sent via a congested link, we now let it be added to the link's backlog queue anyway, thus permitting an oversubscription of one message per source socket. We still create a wakeup item and return an error code, hence instructing the sender to block or stop sending. Only when enough space has been freed up in the link's backlog queue do we issue a wakeup event that allows the sender to continue with the next message, if any. The fact that a socket now can consider a message sent even when the link returns a congestion code means that the sending socket code can be simplified. Also, since this is a good opportunity to get rid of the obsolete 'mtu change' condition in the three socket send functions, we now choose to refactor those functions completely. Signed-off-by: Parthasarathy Bhuvaragan <parthasarathy.bhuvaragan@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-03 22:55:11 +07:00
return rc;
}
static void tipc_link_advance_backlog(struct tipc_link *l,
struct sk_buff_head *xmitq)
{
struct sk_buff *skb, *_skb;
struct tipc_msg *hdr;
u16 seqno = l->snd_nxt;
u16 ack = l->rcv_nxt - 1;
u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
while (skb_queue_len(&l->transmq) < l->window) {
skb = skb_peek(&l->backlogq);
if (!skb)
break;
_skb = skb_clone(skb, GFP_ATOMIC);
if (!_skb)
break;
__skb_dequeue(&l->backlogq);
hdr = buf_msg(skb);
l->backlog[msg_importance(hdr)].len--;
__skb_queue_tail(&l->transmq, skb);
/* next retransmit attempt */
if (link_is_bc_sndlink(l))
TIPC_SKB_CB(skb)->nxt_retr = jiffies + TIPC_BC_RETR_LIM;
__skb_queue_tail(xmitq, _skb);
TIPC_SKB_CB(skb)->ackers = l->ackers;
msg_set_seqno(hdr, seqno);
msg_set_ack(hdr, ack);
msg_set_bcast_ack(hdr, bc_ack);
l->rcv_unacked = 0;
l->stats.sent_pkts++;
seqno++;
}
l->snd_nxt = seqno;
}
/**
* link_retransmit_failure() - Detect repeated retransmit failures
* @l: tipc link sender
* @r: tipc link receiver (= l in case of unicast)
* @from: seqno of the 1st packet in retransmit request
* @rc: returned code
*
* Return: true if the repeated retransmit failures happens, otherwise
* false
*/
static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r,
u16 from, int *rc)
{
struct sk_buff *skb = skb_peek(&l->transmq);
struct tipc_msg *hdr;
if (!skb)
return false;
hdr = buf_msg(skb);
/* Detect repeated retransmit failures on same packet */
if (r->prev_from != from) {
r->prev_from = from;
r->stale_limit = jiffies + msecs_to_jiffies(r->tolerance);
} else if (time_after(jiffies, r->stale_limit)) {
pr_warn("Retransmission failure on link <%s>\n", l->name);
link_print(l, "State of link ");
pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
msg_user(hdr), msg_type(hdr), msg_size(hdr),
msg_errcode(hdr));
pr_info("sqno %u, prev: %x, src: %x\n",
msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));
trace_tipc_list_dump(&l->transmq, true, "retrans failure!");
trace_tipc_link_dump(l, TIPC_DUMP_NONE, "retrans failure!");
trace_tipc_link_dump(r, TIPC_DUMP_NONE, "retrans failure!");
if (link_is_bc_sndlink(l))
*rc = TIPC_LINK_DOWN_EVT;
*rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
return true;
}
return false;
}
/* tipc_link_bc_retrans() - retransmit zero or more packets
* @l: the link to transmit on
* @r: the receiving link ordering the retransmit. Same as l if unicast
* @from: retransmit from (inclusive) this sequence number
* @to: retransmit to (inclusive) this sequence number
* xmitq: queue for accumulating the retransmitted packets
*/
static int tipc_link_bc_retrans(struct tipc_link *l, struct tipc_link *r,
u16 from, u16 to, struct sk_buff_head *xmitq)
{
struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
u16 ack = l->rcv_nxt - 1;
struct tipc_msg *hdr;
int rc = 0;
if (!skb)
return 0;
if (less(to, from))
return 0;
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_link_retrans(r, from, to, &l->transmq);
if (link_retransmit_failure(l, r, from, &rc))
return rc;
skb_queue_walk(&l->transmq, skb) {
hdr = buf_msg(skb);
if (less(msg_seqno(hdr), from))
continue;
if (more(msg_seqno(hdr), to))
break;
if (link_is_bc_sndlink(l)) {
if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
continue;
TIPC_SKB_CB(skb)->nxt_retr = jiffies + TIPC_BC_RETR_LIM;
}
_skb = __pskb_copy(skb, LL_MAX_HEADER + MIN_H_SIZE, GFP_ATOMIC);
if (!_skb)
return 0;
hdr = buf_msg(_skb);
msg_set_ack(hdr, ack);
msg_set_bcast_ack(hdr, bc_ack);
_skb->priority = TC_PRIO_CONTROL;
__skb_queue_tail(xmitq, _skb);
l->stats.retransmitted++;
}
return 0;
}
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
/* tipc_data_input - deliver data and name distr msgs to upper layer
*
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
* Consumes buffer if message is of right type
* Node lock must be held
*/
static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
struct sk_buff_head *inputq)
{
struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq;
struct tipc_msg *hdr = buf_msg(skb);
switch (msg_user(hdr)) {
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
case TIPC_LOW_IMPORTANCE:
case TIPC_MEDIUM_IMPORTANCE:
case TIPC_HIGH_IMPORTANCE:
case TIPC_CRITICAL_IMPORTANCE:
tipc: guarantee that group broadcast doesn't bypass group unicast We need a mechanism guaranteeing that group unicasts sent out from a socket are not bypassed by later sent broadcasts from the same socket. We do this as follows: - Each time a unicast is sent, we set a the broadcast method for the socket to "replicast" and "mandatory". This forces the first subsequent broadcast message to follow the same network and data path as the preceding unicast to a destination, hence preventing it from overtaking the latter. - In order to make the 'same data path' statement above true, we let group unicasts pass through the multicast link input queue, instead of as previously through the unicast link input queue. - In the first broadcast following a unicast, we set a new header flag, requiring all recipients to immediately acknowledge its reception. - During the period before all the expected acknowledges are received, the socket refuses to accept any more broadcast attempts, i.e., by blocking or returning EAGAIN. This period should typically not be longer than a few microseconds. - When all acknowledges have been received, the sending socket will open up for subsequent broadcasts, this time giving the link layer freedom to itself select the best transmission method. - The forced and/or abrupt transmission method changes described above may lead to broadcasts arriving out of order to the recipients. We remedy this by introducing code that checks and if necessary re-orders such messages at the receiving end. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-13 16:04:31 +07:00
if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) {
skb_queue_tail(mc_inputq, skb);
return true;
}
/* fall through */
tipc: guarantee that group broadcast doesn't bypass group unicast We need a mechanism guaranteeing that group unicasts sent out from a socket are not bypassed by later sent broadcasts from the same socket. We do this as follows: - Each time a unicast is sent, we set a the broadcast method for the socket to "replicast" and "mandatory". This forces the first subsequent broadcast message to follow the same network and data path as the preceding unicast to a destination, hence preventing it from overtaking the latter. - In order to make the 'same data path' statement above true, we let group unicasts pass through the multicast link input queue, instead of as previously through the unicast link input queue. - In the first broadcast following a unicast, we set a new header flag, requiring all recipients to immediately acknowledge its reception. - During the period before all the expected acknowledges are received, the socket refuses to accept any more broadcast attempts, i.e., by blocking or returning EAGAIN. This period should typically not be longer than a few microseconds. - When all acknowledges have been received, the sending socket will open up for subsequent broadcasts, this time giving the link layer freedom to itself select the best transmission method. - The forced and/or abrupt transmission method changes described above may lead to broadcasts arriving out of order to the recipients. We remedy this by introducing code that checks and if necessary re-orders such messages at the receiving end. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-13 16:04:31 +07:00
case CONN_MANAGER:
skb_queue_tail(inputq, skb);
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
return true;
case GROUP_PROTOCOL:
skb_queue_tail(mc_inputq, skb);
return true;
case NAME_DISTRIBUTOR:
l->bc_rcvlink->state = LINK_ESTABLISHED;
skb_queue_tail(l->namedq, skb);
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
return true;
case MSG_BUNDLER:
case TUNNEL_PROTOCOL:
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
case MSG_FRAGMENTER:
case BCAST_PROTOCOL:
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
return false;
default:
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
pr_warn("Dropping received illegal msg type\n");
kfree_skb(skb);
return true;
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
};
}
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
/* tipc_link_input - process packet that has passed link protocol check
*
* Consumes buffer
*/
static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
struct sk_buff_head *inputq,
struct sk_buff **reasm_skb)
{
struct tipc_msg *hdr = buf_msg(skb);
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
struct sk_buff *iskb;
struct sk_buff_head tmpq;
int usr = msg_user(hdr);
int pos = 0;
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
if (usr == MSG_BUNDLER) {
skb_queue_head_init(&tmpq);
l->stats.recv_bundles++;
l->stats.recv_bundled += msg_msgcnt(hdr);
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
while (tipc_msg_extract(skb, &iskb, &pos))
tipc_data_input(l, iskb, &tmpq);
tipc_skb_queue_splice_tail(&tmpq, inputq);
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
return 0;
} else if (usr == MSG_FRAGMENTER) {
l->stats.recv_fragments++;
if (tipc_buf_append(reasm_skb, &skb)) {
l->stats.recv_fragmented++;
tipc_data_input(l, skb, inputq);
} else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
pr_warn_ratelimited("Unable to build fragment list\n");
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
tipc: resolve race problem at unicast message reception TIPC handles message cardinality and sequencing at the link layer, before passing messages upwards to the destination sockets. During the upcall from link to socket no locks are held. It is therefore possible, and we see it happen occasionally, that messages arriving in different threads and delivered in sequence still bypass each other before they reach the destination socket. This must not happen, since it violates the sequentiality guarantee. We solve this by adding a new input buffer queue to the link structure. Arriving messages are added safely to the tail of that queue by the link, while the head of the queue is consumed, also safely, by the receiving socket. Sequentiality is secured per socket by only allowing buffers to be dequeued inside the socket lock. Since there may be multiple simultaneous readers of the queue, we use a 'filter' parameter to reduce the risk that they peek the same buffer from the queue, hence also reducing the risk of contention on the receiving socket locks. This solves the sequentiality problem, and seems to cause no measurable performance degradation. A nice side effect of this change is that lock handling in the functions tipc_rcv() and tipc_bcast_rcv() now becomes uniform, something that will enable future simplifications of those functions. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 20:36:41 +07:00
}
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
return 0;
} else if (usr == BCAST_PROTOCOL) {
tipc_bcast_lock(l->net);
tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
tipc_bcast_unlock(l->net);
}
kfree_skb(skb);
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
return 0;
}
/* tipc_link_tnl_rcv() - receive TUNNEL_PROTOCOL message, drop or process the
* inner message along with the ones in the old link's
* deferdq
* @l: tunnel link
* @skb: TUNNEL_PROTOCOL message
* @inputq: queue to put messages ready for delivery
*/
static int tipc_link_tnl_rcv(struct tipc_link *l, struct sk_buff *skb,
struct sk_buff_head *inputq)
{
struct sk_buff **reasm_skb = &l->failover_reasm_skb;
struct sk_buff_head *fdefq = &l->failover_deferdq;
struct tipc_msg *hdr = buf_msg(skb);
struct sk_buff *iskb;
int ipos = 0;
int rc = 0;
u16 seqno;
/* SYNCH_MSG */
if (msg_type(hdr) == SYNCH_MSG)
goto drop;
/* FAILOVER_MSG */
if (!tipc_msg_extract(skb, &iskb, &ipos)) {
pr_warn_ratelimited("Cannot extract FAILOVER_MSG, defq: %d\n",
skb_queue_len(fdefq));
return rc;
}
do {
seqno = buf_seqno(iskb);
if (unlikely(less(seqno, l->drop_point))) {
kfree_skb(iskb);
continue;
}
if (unlikely(seqno != l->drop_point)) {
__tipc_skb_queue_sorted(fdefq, seqno, iskb);
continue;
}
l->drop_point++;
if (!tipc_data_input(l, iskb, inputq))
rc |= tipc_link_input(l, iskb, inputq, reasm_skb);
if (unlikely(rc))
break;
} while ((iskb = __tipc_skb_dequeue(fdefq, l->drop_point)));
drop:
kfree_skb(skb);
return rc;
}
static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
{
bool released = false;
struct sk_buff *skb, *tmp;
skb_queue_walk_safe(&l->transmq, skb, tmp) {
if (more(buf_seqno(skb), acked))
break;
__skb_unlink(skb, &l->transmq);
kfree_skb(skb);
released = true;
}
return released;
}
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
/* tipc_build_gap_ack_blks - build Gap ACK blocks
* @l: tipc link that data have come with gaps in sequence if any
* @data: data buffer to store the Gap ACK blocks after built
*
* returns the actual allocated memory size
*/
static u16 tipc_build_gap_ack_blks(struct tipc_link *l, void *data)
{
struct sk_buff *skb = skb_peek(&l->deferdq);
struct tipc_gap_ack_blks *ga = data;
u16 len, expect, seqno = 0;
u8 n = 0;
if (!skb)
goto exit;
expect = buf_seqno(skb);
skb_queue_walk(&l->deferdq, skb) {
seqno = buf_seqno(skb);
if (unlikely(more(seqno, expect))) {
ga->gacks[n].ack = htons(expect - 1);
ga->gacks[n].gap = htons(seqno - expect);
if (++n >= MAX_GAP_ACK_BLKS) {
pr_info_ratelimited("Too few Gap ACK blocks!\n");
goto exit;
}
} else if (unlikely(less(seqno, expect))) {
pr_warn("Unexpected skb in deferdq!\n");
continue;
}
expect = seqno + 1;
}
/* last block */
ga->gacks[n].ack = htons(seqno);
ga->gacks[n].gap = 0;
n++;
exit:
len = tipc_gap_ack_blks_sz(n);
ga->len = htons(len);
ga->gack_cnt = n;
return len;
}
/* tipc_link_advance_transmq - advance TIPC link transmq queue by releasing
* acked packets, also doing retransmissions if
* gaps found
* @l: tipc link with transmq queue to be advanced
* @acked: seqno of last packet acked by peer without any gaps before
* @gap: # of gap packets
* @ga: buffer pointer to Gap ACK blocks from peer
* @xmitq: queue for accumulating the retransmitted packets if any
*
* In case of a repeated retransmit failures, the call will return shortly
* with a returned code (e.g. TIPC_LINK_DOWN_EVT)
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
*/
static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,
struct tipc_gap_ack_blks *ga,
struct sk_buff_head *xmitq)
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
{
struct sk_buff *skb, *_skb, *tmp;
struct tipc_msg *hdr;
u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
u16 ack = l->rcv_nxt - 1;
u16 seqno, n = 0;
int rc = 0;
if (gap && link_retransmit_failure(l, l, acked + 1, &rc))
return rc;
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
skb_queue_walk_safe(&l->transmq, skb, tmp) {
seqno = buf_seqno(skb);
next_gap_ack:
if (less_eq(seqno, acked)) {
/* release skb */
__skb_unlink(skb, &l->transmq);
kfree_skb(skb);
} else if (less_eq(seqno, acked + gap)) {
/* retransmit skb */
tipc: reduce duplicate packets for unicast traffic For unicast transmission, the current NACK sending althorithm is over- active that forces the sending side to retransmit a packet that is not really lost but just arrived at the receiving side with some delay, or even retransmit same packets that have already been retransmitted before. As a result, many duplicates are observed also under normal condition, ie. without packet loss. One example case is: node1 transmits 1 2 3 4 10 5 6 7 8 9, when node2 receives packet #10, it puts into the deferdq. When the packet #5 comes it sends NACK with gap [6 - 9]. However, shortly after that, when packet #6 arrives, it pulls out packet #10 from the deferfq, but it is still out of order, so it makes another NACK with gap [7 - 9] and so on ... Finally, node1 has to retransmit the packets 5 6 7 8 9 a number of times, but in fact all the packets are not lost at all, so duplicates! This commit reduces duplicates by changing the condition to send NACK, also restricting the retransmissions on individual packets via a timer of about 1ms. However, it also needs to say that too tricky condition for NACKs or too long timeout value for retransmissions will result in performance reducing! The criterias in this commit are found to be effective for both the requirements to reduce duplicates but not affect performance. The tipc_link_rcv() is also improved to only dequeue skb from the link deferdq if it is expected (ie. its seqno <= rcv_nxt). Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:52 +07:00
if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
continue;
TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
_skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
if (!_skb)
continue;
hdr = buf_msg(_skb);
msg_set_ack(hdr, ack);
msg_set_bcast_ack(hdr, bc_ack);
_skb->priority = TC_PRIO_CONTROL;
__skb_queue_tail(xmitq, _skb);
l->stats.retransmitted++;
} else {
/* retry with Gap ACK blocks if any */
if (!ga || n >= ga->gack_cnt)
break;
acked = ntohs(ga->gacks[n].ack);
gap = ntohs(ga->gacks[n].gap);
n++;
goto next_gap_ack;
}
}
return 0;
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
}
/* tipc_link_build_state_msg: prepare link state message for transmission
*
* Note that sending of broadcast ack is coordinated among nodes, to reduce
* risk of ack storms towards the sender
*/
int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
{
if (!l)
return 0;
/* Broadcast ACK must be sent via a unicast link => defer to caller */
if (link_is_bc_rcvlink(l)) {
if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
return 0;
l->rcv_unacked = 0;
/* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
l->snd_nxt = l->rcv_nxt;
return TIPC_LINK_SND_STATE;
}
/* Unicast ACK */
l->rcv_unacked = 0;
l->stats.sent_acks++;
tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
return 0;
}
/* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
*/
void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
{
int mtyp = RESET_MSG;
tipc: guarantee peer bearer id exchange after reboot When a link endpoint is going down locally, e.g., because its interface is being stopped, it will spontaneously send out a RESET message to its peer, informing it about this fact. This saves the peer from detecting the failure via probing, and hence gives both speedier and less resource consuming failure detection on the peer side. According to the link FSM, a receiver of a RESET message, ignoring the reason for it, must now consider the sender ready to come back up, and starts periodically sending out ACTIVATE messages to the peer in order to re-establish the link. Also, according to the FSM, the receiver of an ACTIVATE message can now go directly to state ESTABLISHED and start sending regular traffic packets. This is a well-proven and robust FSM. However, in the case of a reboot, there is a small possibilty that link endpoint on the rebooted node may have been re-created with a new bearer identity between the moment it sent its (pre-boot) RESET and the moment it receives the ACTIVATE from the peer. The new bearer identity cannot be known by the peer according to this scenario, since traffic headers don't convey such information. This is a problem, because both endpoints need to know the correct value of the peer's bearer id at any moment in time in order to be able to produce correct link events for their users. The only way to guarantee this is to enforce a full setup message exchange (RESET + ACTIVATE) even after the reboot, since those messages carry the bearer idientity in their header. In this commit we do this by introducing and setting a "stopping" bit in the header of the spontaneously generated RESET messages, informing the peer that the sender will not be immediately ready to re-establish the link. A receiver seeing this bit must act as if this were a locally detected connectivity failure, and hence has to go through a full two- way setup message exchange before any link can be re-established. Although never reported, this problem seems to have always been around. This protocol addition is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-16 00:33:03 +07:00
struct sk_buff *skb;
if (l->state == LINK_ESTABLISHING)
mtyp = ACTIVATE_MSG;
tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, 0, xmitq);
tipc: guarantee peer bearer id exchange after reboot When a link endpoint is going down locally, e.g., because its interface is being stopped, it will spontaneously send out a RESET message to its peer, informing it about this fact. This saves the peer from detecting the failure via probing, and hence gives both speedier and less resource consuming failure detection on the peer side. According to the link FSM, a receiver of a RESET message, ignoring the reason for it, must now consider the sender ready to come back up, and starts periodically sending out ACTIVATE messages to the peer in order to re-establish the link. Also, according to the FSM, the receiver of an ACTIVATE message can now go directly to state ESTABLISHED and start sending regular traffic packets. This is a well-proven and robust FSM. However, in the case of a reboot, there is a small possibilty that link endpoint on the rebooted node may have been re-created with a new bearer identity between the moment it sent its (pre-boot) RESET and the moment it receives the ACTIVATE from the peer. The new bearer identity cannot be known by the peer according to this scenario, since traffic headers don't convey such information. This is a problem, because both endpoints need to know the correct value of the peer's bearer id at any moment in time in order to be able to produce correct link events for their users. The only way to guarantee this is to enforce a full setup message exchange (RESET + ACTIVATE) even after the reboot, since those messages carry the bearer idientity in their header. In this commit we do this by introducing and setting a "stopping" bit in the header of the spontaneously generated RESET messages, informing the peer that the sender will not be immediately ready to re-establish the link. A receiver seeing this bit must act as if this were a locally detected connectivity failure, and hence has to go through a full two- way setup message exchange before any link can be re-established. Although never reported, this problem seems to have always been around. This protocol addition is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-16 00:33:03 +07:00
/* Inform peer that this endpoint is going down if applicable */
skb = skb_peek_tail(xmitq);
if (skb && (l->state == LINK_RESET))
msg_set_peer_stopping(buf_msg(skb), 1);
}
/* tipc_link_build_nack_msg: prepare link nack message for transmission
* Note that sending of broadcast NACK is coordinated among nodes, to
* reduce the risk of NACK storms towards the sender
*/
static int tipc_link_build_nack_msg(struct tipc_link *l,
struct sk_buff_head *xmitq)
{
u32 def_cnt = ++l->stats.deferred_recv;
tipc: reduce duplicate packets for unicast traffic For unicast transmission, the current NACK sending althorithm is over- active that forces the sending side to retransmit a packet that is not really lost but just arrived at the receiving side with some delay, or even retransmit same packets that have already been retransmitted before. As a result, many duplicates are observed also under normal condition, ie. without packet loss. One example case is: node1 transmits 1 2 3 4 10 5 6 7 8 9, when node2 receives packet #10, it puts into the deferdq. When the packet #5 comes it sends NACK with gap [6 - 9]. However, shortly after that, when packet #6 arrives, it pulls out packet #10 from the deferfq, but it is still out of order, so it makes another NACK with gap [7 - 9] and so on ... Finally, node1 has to retransmit the packets 5 6 7 8 9 a number of times, but in fact all the packets are not lost at all, so duplicates! This commit reduces duplicates by changing the condition to send NACK, also restricting the retransmissions on individual packets via a timer of about 1ms. However, it also needs to say that too tricky condition for NACKs or too long timeout value for retransmissions will result in performance reducing! The criterias in this commit are found to be effective for both the requirements to reduce duplicates but not affect performance. The tipc_link_rcv() is also improved to only dequeue skb from the link deferdq if it is expected (ie. its seqno <= rcv_nxt). Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:52 +07:00
u32 defq_len = skb_queue_len(&l->deferdq);
int match1, match2;
if (link_is_bc_rcvlink(l)) {
match1 = def_cnt & 0xf;
match2 = tipc_own_addr(l->net) & 0xf;
if (match1 == match2)
return TIPC_LINK_SND_STATE;
return 0;
}
tipc: reduce duplicate packets for unicast traffic For unicast transmission, the current NACK sending althorithm is over- active that forces the sending side to retransmit a packet that is not really lost but just arrived at the receiving side with some delay, or even retransmit same packets that have already been retransmitted before. As a result, many duplicates are observed also under normal condition, ie. without packet loss. One example case is: node1 transmits 1 2 3 4 10 5 6 7 8 9, when node2 receives packet #10, it puts into the deferdq. When the packet #5 comes it sends NACK with gap [6 - 9]. However, shortly after that, when packet #6 arrives, it pulls out packet #10 from the deferfq, but it is still out of order, so it makes another NACK with gap [7 - 9] and so on ... Finally, node1 has to retransmit the packets 5 6 7 8 9 a number of times, but in fact all the packets are not lost at all, so duplicates! This commit reduces duplicates by changing the condition to send NACK, also restricting the retransmissions on individual packets via a timer of about 1ms. However, it also needs to say that too tricky condition for NACKs or too long timeout value for retransmissions will result in performance reducing! The criterias in this commit are found to be effective for both the requirements to reduce duplicates but not affect performance. The tipc_link_rcv() is also improved to only dequeue skb from the link deferdq if it is expected (ie. its seqno <= rcv_nxt). Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:52 +07:00
if (defq_len >= 3 && !((defq_len - 3) % 16))
tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
return 0;
}
/* tipc_link_rcv - process TIPC packets/messages arriving from off-node
* @l: the link that should handle the message
* @skb: TIPC packet
* @xmitq: queue to place packets to be sent after this call
*/
int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
struct sk_buff_head *xmitq)
{
struct sk_buff_head *defq = &l->deferdq;
tipc: reduce duplicate packets for unicast traffic For unicast transmission, the current NACK sending althorithm is over- active that forces the sending side to retransmit a packet that is not really lost but just arrived at the receiving side with some delay, or even retransmit same packets that have already been retransmitted before. As a result, many duplicates are observed also under normal condition, ie. without packet loss. One example case is: node1 transmits 1 2 3 4 10 5 6 7 8 9, when node2 receives packet #10, it puts into the deferdq. When the packet #5 comes it sends NACK with gap [6 - 9]. However, shortly after that, when packet #6 arrives, it pulls out packet #10 from the deferfq, but it is still out of order, so it makes another NACK with gap [7 - 9] and so on ... Finally, node1 has to retransmit the packets 5 6 7 8 9 a number of times, but in fact all the packets are not lost at all, so duplicates! This commit reduces duplicates by changing the condition to send NACK, also restricting the retransmissions on individual packets via a timer of about 1ms. However, it also needs to say that too tricky condition for NACKs or too long timeout value for retransmissions will result in performance reducing! The criterias in this commit are found to be effective for both the requirements to reduce duplicates but not affect performance. The tipc_link_rcv() is also improved to only dequeue skb from the link deferdq if it is expected (ie. its seqno <= rcv_nxt). Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:52 +07:00
struct tipc_msg *hdr = buf_msg(skb);
u16 seqno, rcv_nxt, win_lim;
int rc = 0;
tipc: reduce duplicate packets for unicast traffic For unicast transmission, the current NACK sending althorithm is over- active that forces the sending side to retransmit a packet that is not really lost but just arrived at the receiving side with some delay, or even retransmit same packets that have already been retransmitted before. As a result, many duplicates are observed also under normal condition, ie. without packet loss. One example case is: node1 transmits 1 2 3 4 10 5 6 7 8 9, when node2 receives packet #10, it puts into the deferdq. When the packet #5 comes it sends NACK with gap [6 - 9]. However, shortly after that, when packet #6 arrives, it pulls out packet #10 from the deferfq, but it is still out of order, so it makes another NACK with gap [7 - 9] and so on ... Finally, node1 has to retransmit the packets 5 6 7 8 9 a number of times, but in fact all the packets are not lost at all, so duplicates! This commit reduces duplicates by changing the condition to send NACK, also restricting the retransmissions on individual packets via a timer of about 1ms. However, it also needs to say that too tricky condition for NACKs or too long timeout value for retransmissions will result in performance reducing! The criterias in this commit are found to be effective for both the requirements to reduce duplicates but not affect performance. The tipc_link_rcv() is also improved to only dequeue skb from the link deferdq if it is expected (ie. its seqno <= rcv_nxt). Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:52 +07:00
/* Verify and update link state */
if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
return tipc_link_proto_rcv(l, skb, xmitq);
/* Don't send probe at next timeout expiration */
l->silent_intv_cnt = 0;
do {
hdr = buf_msg(skb);
seqno = msg_seqno(hdr);
rcv_nxt = l->rcv_nxt;
win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
if (unlikely(!link_is_up(l))) {
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
if (l->state == LINK_ESTABLISHING)
rc = TIPC_LINK_UP_EVT;
goto drop;
}
/* Drop if outside receive window */
if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
l->stats.duplicates++;
goto drop;
}
/* Forward queues and wake up waiting users */
if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
tipc_link_advance_backlog(l, xmitq);
if (unlikely(!skb_queue_empty(&l->wakeupq)))
link_prepare_wakeup(l);
}
/* Defer delivery if sequence gap */
if (unlikely(seqno != rcv_nxt)) {
__tipc_skb_queue_sorted(defq, seqno, skb);
rc |= tipc_link_build_nack_msg(l, xmitq);
break;
}
/* Deliver packet */
l->rcv_nxt++;
l->stats.recv_pkts++;
if (unlikely(msg_user(hdr) == TUNNEL_PROTOCOL))
rc |= tipc_link_tnl_rcv(l, skb, l->inputq);
else if (!tipc_data_input(l, skb, l->inputq))
rc |= tipc_link_input(l, skb, l->inputq, &l->reasm_buf);
if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
rc |= tipc_link_build_state_msg(l, xmitq);
if (unlikely(rc & ~TIPC_LINK_SND_STATE))
break;
tipc: reduce duplicate packets for unicast traffic For unicast transmission, the current NACK sending althorithm is over- active that forces the sending side to retransmit a packet that is not really lost but just arrived at the receiving side with some delay, or even retransmit same packets that have already been retransmitted before. As a result, many duplicates are observed also under normal condition, ie. without packet loss. One example case is: node1 transmits 1 2 3 4 10 5 6 7 8 9, when node2 receives packet #10, it puts into the deferdq. When the packet #5 comes it sends NACK with gap [6 - 9]. However, shortly after that, when packet #6 arrives, it pulls out packet #10 from the deferfq, but it is still out of order, so it makes another NACK with gap [7 - 9] and so on ... Finally, node1 has to retransmit the packets 5 6 7 8 9 a number of times, but in fact all the packets are not lost at all, so duplicates! This commit reduces duplicates by changing the condition to send NACK, also restricting the retransmissions on individual packets via a timer of about 1ms. However, it also needs to say that too tricky condition for NACKs or too long timeout value for retransmissions will result in performance reducing! The criterias in this commit are found to be effective for both the requirements to reduce duplicates but not affect performance. The tipc_link_rcv() is also improved to only dequeue skb from the link deferdq if it is expected (ie. its seqno <= rcv_nxt). Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:52 +07:00
} while ((skb = __tipc_skb_dequeue(defq, l->rcv_nxt)));
return rc;
drop:
kfree_skb(skb);
return rc;
}
static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
bool probe_reply, u16 rcvgap,
int tolerance, int priority,
struct sk_buff_head *xmitq)
{
struct tipc_link *bcl = l->bc_rcvlink;
struct sk_buff *skb;
struct tipc_msg *hdr;
struct sk_buff_head *dfq = &l->deferdq;
bool node_up = link_is_up(bcl);
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
struct tipc_mon_state *mstate = &l->mon_state;
int dlen = 0;
void *data;
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
u16 glen = 0;
/* Don't send protocol message during reset or link failover */
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
if (tipc_link_is_blocked(l))
return;
if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
return;
if (!skb_queue_empty(dfq))
rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
tipc_max_domain_size + MAX_GAP_ACK_BLKS_SZ,
l->addr, tipc_own_addr(l->net), 0, 0, 0);
if (!skb)
return;
hdr = buf_msg(skb);
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
data = msg_data(hdr);
msg_set_session(hdr, l->session);
msg_set_bearer_id(hdr, l->bearer_id);
msg_set_net_plane(hdr, l->net_plane);
msg_set_next_sent(hdr, l->snd_nxt);
msg_set_ack(hdr, l->rcv_nxt - 1);
msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
tipc: fix broadcast link synchronization problem In commit 2d18ac4ba745 ("tipc: extend broadcast link initialization criteria") we tried to fix a problem with the initial synchronization of broadcast link acknowledge values. Unfortunately that solution is not sufficient to solve the issue. We have seen it happen that LINK_PROTOCOL/STATE packets with a valid non-zero unicast acknowledge number may bypass BCAST_PROTOCOL initialization, NAME_DISTRIBUTOR and other STATE packets with invalid broadcast acknowledge numbers, leading to premature opening of the broadcast link. When the bypassed packets finally arrive, they are inadvertently accepted, and the already correctly initialized acknowledge number in the broadcast receive link is overwritten by the invalid (zero) value of the said packets. After this the broadcast link goes stale. We now fix this by marking the packets where we know the acknowledge value is or may be invalid, and then ignoring the acks from those. To this purpose, we claim an unused bit in the header to indicate that the value is invalid. We set the bit to 1 in the initial BCAST_PROTOCOL synchronization packet and all initial ("bulk") NAME_DISTRIBUTOR packets, plus those LINK_PROTOCOL packets sent out before the broadcast links are fully synchronized. This minor protocol update is fully backwards compatible. Reported-by: John Thompson <thompa.atl@gmail.com> Tested-by: John Thompson <thompa.atl@gmail.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-28 05:51:55 +07:00
msg_set_bc_ack_invalid(hdr, !node_up);
msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
msg_set_link_tolerance(hdr, tolerance);
msg_set_linkprio(hdr, priority);
msg_set_redundant_link(hdr, node_up);
msg_set_seq_gap(hdr, 0);
msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
if (mtyp == STATE_MSG) {
if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
msg_set_seqno(hdr, l->snd_nxt_state++);
msg_set_seq_gap(hdr, rcvgap);
msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
msg_set_probe(hdr, probe);
msg_set_is_keepalive(hdr, probe || probe_reply);
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
if (l->peer_caps & TIPC_GAP_ACK_BLOCK)
glen = tipc_build_gap_ack_blks(l, data);
tipc_mon_prep(l->net, data + glen, &dlen, mstate, l->bearer_id);
msg_set_size(hdr, INT_H_SIZE + glen + dlen);
skb_trim(skb, INT_H_SIZE + glen + dlen);
l->stats.sent_states++;
l->rcv_unacked = 0;
} else {
/* RESET_MSG or ACTIVATE_MSG */
tipc: fix link session and re-establish issues When a link endpoint is re-created (e.g. after a node reboot or interface reset), the link session number is varied by random, the peer endpoint will be synced with this new session number before the link is re-established. However, there is a shortcoming in this mechanism that can lead to the link never re-established or faced with a failure then. It happens when the peer endpoint is ready in ESTABLISHING state, the 'peer_session' as well as the 'in_session' flag have been set, but suddenly this link endpoint leaves. When it comes back with a random session number, there are two situations possible: 1/ If the random session number is larger than (or equal to) the previous one, the peer endpoint will be updated with this new session upon receipt of a RESET_MSG from this endpoint, and the link can be re- established as normal. Otherwise, all the RESET_MSGs from this endpoint will be rejected by the peer. In turn, when this link endpoint receives one ACTIVATE_MSG from the peer, it will move to ESTABLISHED and start to send STATE_MSGs, but again these messages will be dropped by the peer due to wrong session. The peer link endpoint can still become ESTABLISHED after receiving a traffic message from this endpoint (e.g. a BCAST_PROTOCOL or NAME_DISTRIBUTOR), but since all the STATE_MSGs are invalid, the link will be forced down sooner or later! Even in case the random session number is larger than the previous one, it can be that the ACTIVATE_MSG from the peer arrives first, and this link endpoint moves quickly to ESTABLISHED without sending out any RESET_MSG yet. Consequently, the peer link will not be updated with the new session number, and the same link failure scenario as above will happen. 2/ Another situation can be that, the peer link endpoint was reset due to any reasons in the meantime, its link state was set to RESET from ESTABLISHING but still in session, i.e. the 'in_session' flag is not reset... Now, if the random session number from this endpoint is less than the previous one, all the RESET_MSGs from this endpoint will be rejected by the peer. In the other direction, when this link endpoint receives a RESET_MSG from the peer, it moves to ESTABLISHING and starts to send ACTIVATE_MSGs, but all these messages will be rejected by the peer too. As a result, the link cannot be re-established but gets stuck with this link endpoint in state ESTABLISHING and the peer in RESET! Solution: =========== This link endpoint should not go directly to ESTABLISHED when getting ACTIVATE_MSG from the peer which may belong to the old session if the link was re-created. To ensure the session to be correct before the link is re-established, the peer endpoint in ESTABLISHING state will send back the last session number in ACTIVATE_MSG for a verification at this endpoint. Then, if needed, a new and more appropriate session number will be regenerated to force a re-synch first. In addition, when a link in ESTABLISHING state is reset, its state will move to RESET according to the link FSM, along with resetting the 'in_session' flag (and the other data) as a normal link reset, it will also be deleted if requested. The solution is backward compatible. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-11 13:29:43 +07:00
if (mtyp == ACTIVATE_MSG) {
msg_set_dest_session_valid(hdr, 1);
msg_set_dest_session(hdr, l->peer_session);
}
msg_set_max_pkt(hdr, l->advertised_mtu);
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
strcpy(data, l->if_name);
msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
}
if (probe)
l->stats.sent_probes++;
if (rcvgap)
l->stats.sent_nacks++;
skb->priority = TC_PRIO_CONTROL;
__skb_queue_tail(xmitq, skb);
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_proto_build(skb, false, l->name);
}
void tipc_link_create_dummy_tnl_msg(struct tipc_link *l,
struct sk_buff_head *xmitq)
{
u32 onode = tipc_own_addr(l->net);
struct tipc_msg *hdr, *ihdr;
struct sk_buff_head tnlq;
struct sk_buff *skb;
u32 dnode = l->addr;
skb_queue_head_init(&tnlq);
skb = tipc_msg_create(TUNNEL_PROTOCOL, FAILOVER_MSG,
INT_H_SIZE, BASIC_H_SIZE,
dnode, onode, 0, 0, 0);
if (!skb) {
pr_warn("%sunable to create tunnel packet\n", link_co_err);
return;
}
hdr = buf_msg(skb);
msg_set_msgcnt(hdr, 1);
msg_set_bearer_id(hdr, l->peer_bearer_id);
ihdr = (struct tipc_msg *)msg_data(hdr);
tipc_msg_init(onode, ihdr, TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
BASIC_H_SIZE, dnode);
msg_set_errcode(ihdr, TIPC_ERR_NO_PORT);
__skb_queue_tail(&tnlq, skb);
tipc_link_xmit(l, &tnlq, xmitq);
}
/* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
* with contents of the link's transmit and backlog queues.
*/
void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
int mtyp, struct sk_buff_head *xmitq)
{
struct sk_buff_head *fdefq = &tnl->failover_deferdq;
struct sk_buff *skb, *tnlskb;
struct tipc_msg *hdr, tnlhdr;
struct sk_buff_head *queue = &l->transmq;
struct sk_buff_head tmpxq, tnlq;
u16 pktlen, pktcnt, seqno = l->snd_nxt;
if (!tnl)
return;
skb_queue_head_init(&tnlq);
skb_queue_head_init(&tmpxq);
/* At least one packet required for safe algorithm => add dummy */
skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
0, 0, TIPC_ERR_NO_PORT);
if (!skb) {
pr_warn("%sunable to create tunnel packet\n", link_co_err);
return;
}
skb_queue_tail(&tnlq, skb);
tipc_link_xmit(l, &tnlq, &tmpxq);
__skb_queue_purge(&tmpxq);
/* Initialize reusable tunnel packet header */
tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
mtyp, INT_H_SIZE, l->addr);
if (mtyp == SYNCH_MSG)
pktcnt = l->snd_nxt - buf_seqno(skb_peek(&l->transmq));
else
pktcnt = skb_queue_len(&l->transmq);
pktcnt += skb_queue_len(&l->backlogq);
msg_set_msgcnt(&tnlhdr, pktcnt);
msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
tnl:
/* Wrap each packet into a tunnel packet */
skb_queue_walk(queue, skb) {
hdr = buf_msg(skb);
if (queue == &l->backlogq)
msg_set_seqno(hdr, seqno++);
pktlen = msg_size(hdr);
msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
if (!tnlskb) {
pr_warn("%sunable to send packet\n", link_co_err);
return;
}
skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
__skb_queue_tail(&tnlq, tnlskb);
}
if (queue != &l->backlogq) {
queue = &l->backlogq;
goto tnl;
2014-02-14 05:29:11 +07:00
}
tipc_link_xmit(tnl, &tnlq, xmitq);
if (mtyp == FAILOVER_MSG) {
tnl->drop_point = l->rcv_nxt;
tnl->failover_reasm_skb = l->reasm_buf;
l->reasm_buf = NULL;
/* Failover the link's deferdq */
if (unlikely(!skb_queue_empty(fdefq))) {
pr_warn("Link failover deferdq not empty: %d!\n",
skb_queue_len(fdefq));
__skb_queue_purge(fdefq);
}
skb_queue_splice_init(&l->deferdq, fdefq);
}
}
tipc: fix missing Name entries due to half-failover TIPC link can temporarily fall into "half-establish" that only one of the link endpoints is ESTABLISHED and starts to send traffic, PROTOCOL messages, whereas the other link endpoint is not up (e.g. immediately when the endpoint receives ACTIVATE_MSG, the network interface goes down...). This is a normal situation and will be settled because the link endpoint will be eventually brought down after the link tolerance time. However, the situation will become worse when the second link is established before the first link endpoint goes down, For example: 1. Both links <1A-2A>, <1B-2B> down 2. Link endpoint 2A up, but 1A still down (e.g. due to network disturbance, wrong session, etc.) 3. Link <1B-2B> up 4. Link endpoint 2A down (e.g. due to link tolerance timeout) 5. Node B starts failover onto link <1B-2B> ==> Node A does never start link failover. When the "half-failover" situation happens, two consequences have been observed: a) Peer link/node gets stuck in FAILINGOVER state; b) Traffic or user messages that peer node is trying to failover onto the second link can be partially or completely dropped by this node. The consequence a) was actually solved by commit c140eb166d68 ("tipc: fix failover problem"), but that commit didn't cover the b). It's due to the fact that the tunnel link endpoint has never been prepared for a failover, so the 'l->drop_point' (and the other data...) is not set correctly. When a TUNNEL_MSG from peer node arrives on the link, depending on the inner message's seqno and the current 'l->drop_point' value, the message can be dropped (- treated as a duplicate message) or processed. At this early stage, the traffic messages from peer are likely to be NAME_DISTRIBUTORs, this means some name table entries will be missed on the node forever! The commit resolves the issue by starting the FAILOVER process on this node as well. Another benefit from this solution is that we ensure the link will not be re-established until the failover ends. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-02 17:23:23 +07:00
/**
* tipc_link_failover_prepare() - prepare tnl for link failover
*
* This is a special version of the precursor - tipc_link_tnl_prepare(),
* see the tipc_node_link_failover() for details
*
* @l: failover link
* @tnl: tunnel link
* @xmitq: queue for messages to be xmited
*/
void tipc_link_failover_prepare(struct tipc_link *l, struct tipc_link *tnl,
struct sk_buff_head *xmitq)
{
struct sk_buff_head *fdefq = &tnl->failover_deferdq;
tipc_link_create_dummy_tnl_msg(tnl, xmitq);
/* This failover link enpoint was never established before,
* so it has not received anything from peer.
* Otherwise, it must be a normal failover situation or the
* node has entered SELF_DOWN_PEER_LEAVING and both peer nodes
* would have to start over from scratch instead.
*/
tnl->drop_point = 1;
tnl->failover_reasm_skb = NULL;
/* Initiate the link's failover deferdq */
if (unlikely(!skb_queue_empty(fdefq))) {
pr_warn("Link failover deferdq not empty: %d!\n",
skb_queue_len(fdefq));
__skb_queue_purge(fdefq);
}
}
/* tipc_link_validate_msg(): validate message against current link state
* Returns true if message should be accepted, otherwise false
*/
bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr)
{
u16 curr_session = l->peer_session;
u16 session = msg_session(hdr);
int mtyp = msg_type(hdr);
if (msg_user(hdr) != LINK_PROTOCOL)
return true;
switch (mtyp) {
case RESET_MSG:
if (!l->in_session)
return true;
/* Accept only RESET with new session number */
return more(session, curr_session);
case ACTIVATE_MSG:
if (!l->in_session)
return true;
/* Accept only ACTIVATE with new or current session number */
return !less(session, curr_session);
case STATE_MSG:
/* Accept only STATE with current session number */
if (!l->in_session)
return false;
if (session != curr_session)
return false;
/* Extra sanity check */
if (!link_is_up(l) && msg_ack(hdr))
return false;
if (!(l->peer_caps & TIPC_LINK_PROTO_SEQNO))
return true;
/* Accept only STATE with new sequence number */
return !less(msg_seqno(hdr), l->rcv_nxt_state);
default:
return false;
}
}
/* tipc_link_proto_rcv(): receive link level protocol message :
* Note that network plane id propagates through the network, and may
* change at any time. The node with lowest numerical id determines
* network plane
*/
static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
struct sk_buff_head *xmitq)
{
struct tipc_msg *hdr = buf_msg(skb);
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
struct tipc_gap_ack_blks *ga = NULL;
u16 rcvgap = 0;
u16 ack = msg_ack(hdr);
u16 gap = msg_seq_gap(hdr);
u16 peers_snd_nxt = msg_next_sent(hdr);
u16 peers_tol = msg_link_tolerance(hdr);
u16 peers_prio = msg_linkprio(hdr);
tipc: fix stale link problem during synchronization Recent changes to the link synchronization means that we can now just drop packets arriving on the synchronizing link before the synch point is reached. This has lead to significant simplifications to the implementation, but also turns out to have a flip side that we need to consider. Under unlucky circumstances, the two endpoints may end up repeatedly dropping each other's packets, while immediately asking for retransmission of the same packets, just to drop them once more. This pattern will eventually be broken when the synch point is reached on the other link, but before that, the endpoints may have arrived at the retransmission limit (stale counter) that indicates that the link should be broken. We see this happen at rare occasions. The fix for this is to not ask for retransmissions when a link is in state LINK_SYNCHING. The fact that the link has reached this state means that it has already received the first SYNCH packet, and that it knows the synch point. Hence, it doesn't need any more packets until the other link has reached the synch point, whereafter it can go ahead and ask for the missing packets. However, because of the reduced traffic on the synching link that follows this change, it may now take longer to discover that the synch point has been reached. We compensate for this by letting all packets, on any of the links, trig a check for synchronization termination. This is possible because the packets themselves don't contain any information that is needed for discovering this condition. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-20 13:12:56 +07:00
u16 rcv_nxt = l->rcv_nxt;
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
u16 dlen = msg_data_sz(hdr);
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
int mtyp = msg_type(hdr);
bool reply = msg_probe(hdr);
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
u16 glen = 0;
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
void *data;
char *if_name;
int rc = 0;
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_proto_rcv(skb, false, l->name);
if (tipc_link_is_blocked(l) || !xmitq)
goto exit;
if (tipc_own_addr(l->net) > msg_prevnode(hdr))
l->net_plane = msg_net_plane(hdr);
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
skb_linearize(skb);
hdr = buf_msg(skb);
data = msg_data(hdr);
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
if (!tipc_link_validate_msg(l, hdr)) {
trace_tipc_skb_dump(skb, false, "PROTO invalid (1)!");
trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (1)!");
goto exit;
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
}
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
switch (mtyp) {
case RESET_MSG:
case ACTIVATE_MSG:
/* Complete own link name with peer's interface name */
if_name = strrchr(l->name, ':') + 1;
if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
break;
if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
break;
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
strncpy(if_name, data, TIPC_MAX_IF_NAME);
/* Update own tolerance if peer indicates a non-zero value */
if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
l->tolerance = peers_tol;
l->bc_rcvlink->tolerance = peers_tol;
}
/* Update own priority if peer's priority is higher */
if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
l->priority = peers_prio;
tipc: fix link re-establish failure When a link failure is detected locally, the link is reset, the flag link->in_session is set to false, and a RESET_MSG with the 'stopping' bit set is sent to the peer. The purpose of this bit is to inform the peer that this endpoint just is going down, and that the peer should handle the reception of this particular RESET message as a local failure. This forces the peer to accept another RESET or ACTIVATE message from this endpoint before it can re-establish the link. This again is necessary to ensure that link session numbers are properly exchanged before the link comes up again. If a failure is detected locally at the same time at the peer endpoint this will do the same, which is also a correct behavior. However, when receiving such messages, the endpoints will not distinguish between 'stopping' RESETs and ordinary ones when it comes to updating session numbers. Both endpoints will copy the received session number and set their 'in_session' flags to true at the reception, while they are still expecting another RESET from the peer before they can go ahead and re-establish. This is contradictory, since, after applying the validation check referred to below, the 'in_session' flag will cause rejection of all such messages, and the link will never come up again. We now fix this by not only handling received RESET/STOPPING messages as a local failure, but also by omitting to set a new session number and the 'in_session' flag in such cases. Fixes: 7ea817f4e832 ("tipc: check session number before accepting link protocol messages") Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-11 05:30:24 +07:00
/* If peer is going down we want full re-establish cycle */
if (msg_peer_stopping(hdr)) {
tipc: guarantee peer bearer id exchange after reboot When a link endpoint is going down locally, e.g., because its interface is being stopped, it will spontaneously send out a RESET message to its peer, informing it about this fact. This saves the peer from detecting the failure via probing, and hence gives both speedier and less resource consuming failure detection on the peer side. According to the link FSM, a receiver of a RESET message, ignoring the reason for it, must now consider the sender ready to come back up, and starts periodically sending out ACTIVATE messages to the peer in order to re-establish the link. Also, according to the FSM, the receiver of an ACTIVATE message can now go directly to state ESTABLISHED and start sending regular traffic packets. This is a well-proven and robust FSM. However, in the case of a reboot, there is a small possibilty that link endpoint on the rebooted node may have been re-created with a new bearer identity between the moment it sent its (pre-boot) RESET and the moment it receives the ACTIVATE from the peer. The new bearer identity cannot be known by the peer according to this scenario, since traffic headers don't convey such information. This is a problem, because both endpoints need to know the correct value of the peer's bearer id at any moment in time in order to be able to produce correct link events for their users. The only way to guarantee this is to enforce a full setup message exchange (RESET + ACTIVATE) even after the reboot, since those messages carry the bearer idientity in their header. In this commit we do this by introducing and setting a "stopping" bit in the header of the spontaneously generated RESET messages, informing the peer that the sender will not be immediately ready to re-establish the link. A receiver seeing this bit must act as if this were a locally detected connectivity failure, and hence has to go through a full two- way setup message exchange before any link can be re-established. Although never reported, this problem seems to have always been around. This protocol addition is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-16 00:33:03 +07:00
rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
tipc: fix link re-establish failure When a link failure is detected locally, the link is reset, the flag link->in_session is set to false, and a RESET_MSG with the 'stopping' bit set is sent to the peer. The purpose of this bit is to inform the peer that this endpoint just is going down, and that the peer should handle the reception of this particular RESET message as a local failure. This forces the peer to accept another RESET or ACTIVATE message from this endpoint before it can re-establish the link. This again is necessary to ensure that link session numbers are properly exchanged before the link comes up again. If a failure is detected locally at the same time at the peer endpoint this will do the same, which is also a correct behavior. However, when receiving such messages, the endpoints will not distinguish between 'stopping' RESETs and ordinary ones when it comes to updating session numbers. Both endpoints will copy the received session number and set their 'in_session' flags to true at the reception, while they are still expecting another RESET from the peer before they can go ahead and re-establish. This is contradictory, since, after applying the validation check referred to below, the 'in_session' flag will cause rejection of all such messages, and the link will never come up again. We now fix this by not only handling received RESET/STOPPING messages as a local failure, but also by omitting to set a new session number and the 'in_session' flag in such cases. Fixes: 7ea817f4e832 ("tipc: check session number before accepting link protocol messages") Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-11 05:30:24 +07:00
break;
}
tipc: fix link session and re-establish issues When a link endpoint is re-created (e.g. after a node reboot or interface reset), the link session number is varied by random, the peer endpoint will be synced with this new session number before the link is re-established. However, there is a shortcoming in this mechanism that can lead to the link never re-established or faced with a failure then. It happens when the peer endpoint is ready in ESTABLISHING state, the 'peer_session' as well as the 'in_session' flag have been set, but suddenly this link endpoint leaves. When it comes back with a random session number, there are two situations possible: 1/ If the random session number is larger than (or equal to) the previous one, the peer endpoint will be updated with this new session upon receipt of a RESET_MSG from this endpoint, and the link can be re- established as normal. Otherwise, all the RESET_MSGs from this endpoint will be rejected by the peer. In turn, when this link endpoint receives one ACTIVATE_MSG from the peer, it will move to ESTABLISHED and start to send STATE_MSGs, but again these messages will be dropped by the peer due to wrong session. The peer link endpoint can still become ESTABLISHED after receiving a traffic message from this endpoint (e.g. a BCAST_PROTOCOL or NAME_DISTRIBUTOR), but since all the STATE_MSGs are invalid, the link will be forced down sooner or later! Even in case the random session number is larger than the previous one, it can be that the ACTIVATE_MSG from the peer arrives first, and this link endpoint moves quickly to ESTABLISHED without sending out any RESET_MSG yet. Consequently, the peer link will not be updated with the new session number, and the same link failure scenario as above will happen. 2/ Another situation can be that, the peer link endpoint was reset due to any reasons in the meantime, its link state was set to RESET from ESTABLISHING but still in session, i.e. the 'in_session' flag is not reset... Now, if the random session number from this endpoint is less than the previous one, all the RESET_MSGs from this endpoint will be rejected by the peer. In the other direction, when this link endpoint receives a RESET_MSG from the peer, it moves to ESTABLISHING and starts to send ACTIVATE_MSGs, but all these messages will be rejected by the peer too. As a result, the link cannot be re-established but gets stuck with this link endpoint in state ESTABLISHING and the peer in RESET! Solution: =========== This link endpoint should not go directly to ESTABLISHED when getting ACTIVATE_MSG from the peer which may belong to the old session if the link was re-created. To ensure the session to be correct before the link is re-established, the peer endpoint in ESTABLISHING state will send back the last session number in ACTIVATE_MSG for a verification at this endpoint. Then, if needed, a new and more appropriate session number will be regenerated to force a re-synch first. In addition, when a link in ESTABLISHING state is reset, its state will move to RESET according to the link FSM, along with resetting the 'in_session' flag (and the other data) as a normal link reset, it will also be deleted if requested. The solution is backward compatible. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-11 13:29:43 +07:00
/* If this endpoint was re-created while peer was ESTABLISHING
* it doesn't know current session number. Force re-synch.
*/
if (mtyp == ACTIVATE_MSG && msg_dest_session_valid(hdr) &&
l->session != msg_dest_session(hdr)) {
if (less(l->session, msg_dest_session(hdr)))
l->session = msg_dest_session(hdr) + 1;
break;
}
tipc: fix link re-establish failure When a link failure is detected locally, the link is reset, the flag link->in_session is set to false, and a RESET_MSG with the 'stopping' bit set is sent to the peer. The purpose of this bit is to inform the peer that this endpoint just is going down, and that the peer should handle the reception of this particular RESET message as a local failure. This forces the peer to accept another RESET or ACTIVATE message from this endpoint before it can re-establish the link. This again is necessary to ensure that link session numbers are properly exchanged before the link comes up again. If a failure is detected locally at the same time at the peer endpoint this will do the same, which is also a correct behavior. However, when receiving such messages, the endpoints will not distinguish between 'stopping' RESETs and ordinary ones when it comes to updating session numbers. Both endpoints will copy the received session number and set their 'in_session' flags to true at the reception, while they are still expecting another RESET from the peer before they can go ahead and re-establish. This is contradictory, since, after applying the validation check referred to below, the 'in_session' flag will cause rejection of all such messages, and the link will never come up again. We now fix this by not only handling received RESET/STOPPING messages as a local failure, but also by omitting to set a new session number and the 'in_session' flag in such cases. Fixes: 7ea817f4e832 ("tipc: check session number before accepting link protocol messages") Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-11 05:30:24 +07:00
/* ACTIVATE_MSG serves as PEER_RESET if link is already down */
if (mtyp == RESET_MSG || !link_is_up(l))
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
/* ACTIVATE_MSG takes up link if it was already locally reset */
tipc: fix link re-establish failure When a link failure is detected locally, the link is reset, the flag link->in_session is set to false, and a RESET_MSG with the 'stopping' bit set is sent to the peer. The purpose of this bit is to inform the peer that this endpoint just is going down, and that the peer should handle the reception of this particular RESET message as a local failure. This forces the peer to accept another RESET or ACTIVATE message from this endpoint before it can re-establish the link. This again is necessary to ensure that link session numbers are properly exchanged before the link comes up again. If a failure is detected locally at the same time at the peer endpoint this will do the same, which is also a correct behavior. However, when receiving such messages, the endpoints will not distinguish between 'stopping' RESETs and ordinary ones when it comes to updating session numbers. Both endpoints will copy the received session number and set their 'in_session' flags to true at the reception, while they are still expecting another RESET from the peer before they can go ahead and re-establish. This is contradictory, since, after applying the validation check referred to below, the 'in_session' flag will cause rejection of all such messages, and the link will never come up again. We now fix this by not only handling received RESET/STOPPING messages as a local failure, but also by omitting to set a new session number and the 'in_session' flag in such cases. Fixes: 7ea817f4e832 ("tipc: check session number before accepting link protocol messages") Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-11 05:30:24 +07:00
if (mtyp == ACTIVATE_MSG && l->state == LINK_ESTABLISHING)
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
rc = TIPC_LINK_UP_EVT;
l->peer_session = msg_session(hdr);
l->in_session = true;
l->peer_bearer_id = msg_bearer_id(hdr);
if (l->mtu > msg_max_pkt(hdr))
l->mtu = msg_max_pkt(hdr);
break;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
case STATE_MSG:
l->rcv_nxt_state = msg_seqno(hdr) + 1;
/* Update own tolerance if peer indicates a non-zero value */
if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
l->tolerance = peers_tol;
l->bc_rcvlink->tolerance = peers_tol;
}
/* Update own prio if peer indicates a different value */
if ((peers_prio != l->priority) &&
in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) {
l->priority = peers_prio;
rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
}
l->silent_intv_cnt = 0;
l->stats.recv_states++;
if (msg_probe(hdr))
l->stats.recv_probes++;
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
if (!link_is_up(l)) {
if (l->state == LINK_ESTABLISHING)
rc = TIPC_LINK_UP_EVT;
break;
tipc: delay ESTABLISH state event when link is established Link establishing, just like link teardown, is a non-atomic action, in the sense that discovering that conditions are right to establish a link, and the actual adding of the link to one of the node's send slots is done in two different lock contexts. The link FSM is designed to help bridging the gap between the two contexts in a safe manner. We have now discovered a weakness in the implementaton of this FSM. Because we directly let the link go from state LINK_ESTABLISHING to state LINK_ESTABLISHED already in the first lock context, we are unable to distinguish between a fully established link, i.e., a link that has been added to its slot, and a link that has not yet reached the second lock context. It may hence happen that a manual intervention, e.g., when disabling an interface, causes the function tipc_node_link_down() to try removing the link from the node slots, decrementing its active link counter etc, although the link was never added there in the first place. We solve this by delaying the actual state change until we reach the second lock context, inside the function tipc_node_link_up(). This makes it possible for potentail callers of __tipc_node_link_down() to know if they should proceed or not, and the problem is solved. Unforunately, the situation described above also has a second problem. Since there by necessity is a tipc_node_link_up() call pending once the node lock has been released, we must defuse that call by setting the link back from LINK_ESTABLISHING to LINK_RESET state. This forces us to make a slight modification to the link FSM, which will now look as follows. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | +----------------+ | | | RESET_EVT| |RESET_EVT | | | | | | | | | | |ESTABLISH_EVT | | | | +-------------+ | | | | | | RESET_EVT | | | | | | | | | | | V V V | | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-16 01:52:44 +07:00
}
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
/* Receive Gap ACK blocks from peer if any */
if (l->peer_caps & TIPC_GAP_ACK_BLOCK) {
ga = (struct tipc_gap_ack_blks *)data;
glen = ntohs(ga->len);
/* sanity check: if failed, ignore Gap ACK blocks */
if (glen != tipc_gap_ack_blks_sz(ga->gack_cnt))
ga = NULL;
}
tipc_mon_rcv(l->net, data + glen, dlen - glen, l->addr,
tipc: add neighbor monitoring framework TIPC based clusters are by default set up with full-mesh link connectivity between all nodes. Those links are expected to provide a short failure detection time, by default set to 1500 ms. Because of this, the background load for neighbor monitoring in an N-node cluster increases with a factor N on each node, while the overall monitoring traffic through the network infrastructure increases at a ~(N * (N - 1)) rate. Experience has shown that such clusters don't scale well beyond ~100 nodes unless we significantly increase failure discovery tolerance. This commit introduces a framework and an algorithm that drastically reduces this background load, while basically maintaining the original failure detection times across the whole cluster. Using this algorithm, background load will now grow at a rate of ~(2 * sqrt(N)) per node, and at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will now have to actively monitor 38 neighbors in a 400-node cluster, instead of as before 399. This "Overlapping Ring Supervision Algorithm" is completely distributed and employs no centralized or coordinated state. It goes as follows: - Each node makes up a linearly ascending, circular list of all its N known neighbors, based on their TIPC node identity. This algorithm must be the same on all nodes. - The node then selects the next M = sqrt(N) - 1 nodes downstream from itself in the list, and chooses to actively monitor those. This is called its "local monitoring domain". - It creates a domain record describing the monitoring domain, and piggy-backs this in the data area of all neighbor monitoring messages (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in the cluster eventually (default within 400 ms) will learn about its monitoring domain. - Whenever a node discovers a change in its local domain, e.g., a node has been added or has gone down, it creates and sends out a new version of its node record to inform all neighbors about the change. - A node receiving a domain record from anybody outside its local domain matches this against its own list (which may not look the same), and chooses to not actively monitor those members of the received domain record that are also present in its own list. Instead, it relies on indications from the direct monitoring nodes if an indirectly monitored node has gone up or down. If a node is indicated lost, the receiving node temporarily activates its own direct monitoring towards that node in order to confirm, or not, that it is actually gone. - Since each node is actively monitoring sqrt(N) downstream neighbors, each node is also actively monitored by the same number of upstream neighbors. This means that all non-direct monitoring nodes normally will receive sqrt(N) indications that a node is gone. - A major drawback with ring monitoring is how it handles failures that cause massive network partitionings. If both a lost node and all its direct monitoring neighbors are inside the lost partition, the nodes in the remaining partition will never receive indications about the loss. To overcome this, each node also chooses to actively monitor some nodes outside its local domain. Those nodes are called remote domain "heads", and are selected in such a way that no node in the cluster will be more than two direct monitoring hops away. Because of this, each node, apart from monitoring the member of its local domain, will also typically monitor sqrt(N) remote head nodes. - As an optimization, local list status, domain status and domain records are marked with a generation number. This saves senders from unnecessarily conveying unaltered domain records, and receivers from performing unneeded re-adaptations of their node monitoring list, such as re-assigning domain heads. - As a measure of caution we have added the possibility to disable the new algorithm through configuration. We do this by keeping a threshold value for the cluster size; a cluster that grows beyond this value will switch from full-mesh to ring monitoring, and vice versa when it shrinks below the value. This means that if the threshold is set to a value larger than any anticipated cluster size (default size is 32) the new algorithm is effectively disabled. A patch set for altering the threshold value and for listing the table contents will follow shortly. - This change is fully backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-14 07:46:22 +07:00
&l->mon_state, l->bearer_id);
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
/* Send NACK if peer has sent pkts we haven't received yet */
tipc: fix stale link problem during synchronization Recent changes to the link synchronization means that we can now just drop packets arriving on the synchronizing link before the synch point is reached. This has lead to significant simplifications to the implementation, but also turns out to have a flip side that we need to consider. Under unlucky circumstances, the two endpoints may end up repeatedly dropping each other's packets, while immediately asking for retransmission of the same packets, just to drop them once more. This pattern will eventually be broken when the synch point is reached on the other link, but before that, the endpoints may have arrived at the retransmission limit (stale counter) that indicates that the link should be broken. We see this happen at rare occasions. The fix for this is to not ask for retransmissions when a link is in state LINK_SYNCHING. The fact that the link has reached this state means that it has already received the first SYNCH packet, and that it knows the synch point. Hence, it doesn't need any more packets until the other link has reached the synch point, whereafter it can go ahead and ask for the missing packets. However, because of the reduced traffic on the synching link that follows this change, it may now take longer to discover that the synch point has been reached. We compensate for this by letting all packets, on any of the links, trig a check for synchronization termination. This is possible because the packets themselves don't contain any information that is needed for discovering this condition. Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-20 13:12:56 +07:00
if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
rcvgap = peers_snd_nxt - l->rcv_nxt;
if (rcvgap || reply)
tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,
rcvgap, 0, 0, xmitq);
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
rc |= tipc_link_advance_transmq(l, ack, gap, ga, xmitq);
/* If NACK, retransmit will now start at right position */
tipc: improve TIPC throughput by Gap ACK blocks During unicast link transmission, it's observed very often that because of one or a few lost/dis-ordered packets, the sending side will fastly reach the send window limit and must wait for the packets to be arrived at the receiving side or in the worst case, a retransmission must be done first. The sending side cannot release a lot of subsequent packets in its transmq even though all of them might have already been received by the receiving side. That is, one or two packets dis-ordered/lost and dozens of packets have to wait, this obviously reduces the overall throughput! This commit introduces an algorithm to overcome this by using "Gap ACK blocks". Basically, a Gap ACK block will consist of <ack, gap> numbers that describes the link deferdq where packets have been got by the receiving side but with gaps, for example: link deferdq: [1 2 3 4 10 11 13 14 15 20] --> Gap ACK blocks: <4, 5>, <11, 1>, <15, 4>, <20, 0> The Gap ACK blocks will be sent to the sending side along with the traditional ACK or NACK message. Immediately when receiving the message the sending side will now not only release from its transmq the packets ack-ed by the ACK but also by the Gap ACK blocks! So, more packets can be enqueued and transmitted. In addition, the sending side can now do "multi-retransmissions" according to the Gaps reported in the Gap ACK blocks. The new algorithm as verified helps greatly improve the TIPC throughput especially under packet loss condition. So far, a maximum of 32 blocks is quite enough without any "Too few Gap ACK blocks" reports with a 5.0% packet loss rate, however this number can be increased in the furture if needed. Also, the patch is backward compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-04 11:09:51 +07:00
if (gap)
l->stats.recv_nacks++;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
tipc_link_advance_backlog(l, xmitq);
if (unlikely(!skb_queue_empty(&l->wakeupq)))
link_prepare_wakeup(l);
}
exit:
kfree_skb(skb);
return rc;
}
/* tipc_link_build_bc_proto_msg() - create broadcast protocol message
*/
static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
u16 peers_snd_nxt,
struct sk_buff_head *xmitq)
{
struct sk_buff *skb;
struct tipc_msg *hdr;
struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
u16 ack = l->rcv_nxt - 1;
u16 gap_to = peers_snd_nxt - 1;
skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
if (!skb)
return false;
hdr = buf_msg(skb);
msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
msg_set_bcast_ack(hdr, ack);
msg_set_bcgap_after(hdr, ack);
if (dfrd_skb)
gap_to = buf_seqno(dfrd_skb) - 1;
msg_set_bcgap_to(hdr, gap_to);
msg_set_non_seq(hdr, bcast);
__skb_queue_tail(xmitq, skb);
return true;
}
/* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
*
* Give a newly added peer node the sequence number where it should
* start receiving and acking broadcast packets.
*/
static void tipc_link_build_bc_init_msg(struct tipc_link *l,
struct sk_buff_head *xmitq)
{
struct sk_buff_head list;
__skb_queue_head_init(&list);
if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
return;
tipc: fix broadcast link synchronization problem In commit 2d18ac4ba745 ("tipc: extend broadcast link initialization criteria") we tried to fix a problem with the initial synchronization of broadcast link acknowledge values. Unfortunately that solution is not sufficient to solve the issue. We have seen it happen that LINK_PROTOCOL/STATE packets with a valid non-zero unicast acknowledge number may bypass BCAST_PROTOCOL initialization, NAME_DISTRIBUTOR and other STATE packets with invalid broadcast acknowledge numbers, leading to premature opening of the broadcast link. When the bypassed packets finally arrive, they are inadvertently accepted, and the already correctly initialized acknowledge number in the broadcast receive link is overwritten by the invalid (zero) value of the said packets. After this the broadcast link goes stale. We now fix this by marking the packets where we know the acknowledge value is or may be invalid, and then ignoring the acks from those. To this purpose, we claim an unused bit in the header to indicate that the value is invalid. We set the bit to 1 in the initial BCAST_PROTOCOL synchronization packet and all initial ("bulk") NAME_DISTRIBUTOR packets, plus those LINK_PROTOCOL packets sent out before the broadcast links are fully synchronized. This minor protocol update is fully backwards compatible. Reported-by: John Thompson <thompa.atl@gmail.com> Tested-by: John Thompson <thompa.atl@gmail.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-28 05:51:55 +07:00
msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true);
tipc_link_xmit(l, &list, xmitq);
}
/* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
*/
void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
{
int mtyp = msg_type(hdr);
u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
if (link_is_up(l))
return;
if (msg_user(hdr) == BCAST_PROTOCOL) {
l->rcv_nxt = peers_snd_nxt;
l->state = LINK_ESTABLISHED;
return;
}
if (l->peer_caps & TIPC_BCAST_SYNCH)
return;
if (msg_peer_node_is_up(hdr))
return;
/* Compatibility: accept older, less safe initial synch data */
if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
l->rcv_nxt = peers_snd_nxt;
}
/* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
*/
int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
struct sk_buff_head *xmitq)
{
struct tipc_link *snd_l = l->bc_sndlink;
u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
u16 from = msg_bcast_ack(hdr) + 1;
u16 to = from + msg_bc_gap(hdr) - 1;
int rc = 0;
if (!link_is_up(l))
return rc;
if (!msg_peer_node_is_up(hdr))
return rc;
/* Open when peer ackowledges our bcast init msg (pkt #1) */
if (msg_ack(hdr))
l->bc_peer_is_up = true;
if (!l->bc_peer_is_up)
return rc;
l->stats.recv_nacks++;
/* Ignore if peers_snd_nxt goes beyond receive window */
if (more(peers_snd_nxt, l->rcv_nxt + l->window))
return rc;
rc = tipc_link_bc_retrans(snd_l, l, from, to, xmitq);
l->snd_nxt = peers_snd_nxt;
if (link_bc_rcv_gap(l))
rc |= TIPC_LINK_SND_STATE;
/* Return now if sender supports nack via STATE messages */
if (l->peer_caps & TIPC_BCAST_STATE_NACK)
return rc;
/* Otherwise, be backwards compatible */
if (!more(peers_snd_nxt, l->rcv_nxt)) {
l->nack_state = BC_NACK_SND_CONDITIONAL;
return 0;
}
/* Don't NACK if one was recently sent or peeked */
if (l->nack_state == BC_NACK_SND_SUPPRESS) {
l->nack_state = BC_NACK_SND_UNCONDITIONAL;
return 0;
}
/* Conditionally delay NACK sending until next synch rcv */
if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
l->nack_state = BC_NACK_SND_UNCONDITIONAL;
if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
return 0;
}
/* Send NACK now but suppress next one */
tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
l->nack_state = BC_NACK_SND_SUPPRESS;
return 0;
}
void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
struct sk_buff_head *xmitq)
{
struct sk_buff *skb, *tmp;
struct tipc_link *snd_l = l->bc_sndlink;
if (!link_is_up(l) || !l->bc_peer_is_up)
return;
if (!more(acked, l->acked))
return;
tipc: add trace_events for tipc link The commit adds the new trace_events for TIPC link object: trace_tipc_link_timeout() trace_tipc_link_fsm() trace_tipc_link_reset() trace_tipc_link_too_silent() trace_tipc_link_retrans() trace_tipc_link_bc_ack() trace_tipc_link_conges() And the traces for PROTOCOL messages at building and receiving: trace_tipc_proto_build() trace_tipc_proto_rcv() Note: a) The 'tipc_link_too_silent' event will only happen when the 'silent_intv_cnt' is about to reach the 'abort_limit' value (and the event is enabled). The benefit for this kind of event is that we can get an early indication about TIPC link loss issue due to timeout, then can do some necessary actions for troubleshooting. For example: To trigger the 'tipc_proto_rcv' when the 'too_silent' event occurs: echo 'enable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_too_silent/trigger And disable it when TIPC link is reset: echo 'disable_event:tipc:tipc_proto_rcv' > \ events/tipc/tipc_link_reset/trigger b) The 'tipc_link_retrans' or 'tipc_link_bc_ack' event is useful to trace TIPC retransmission issues. In addition, the commit adds the 'trace_tipc_list/link_dump()' at the 'retransmission failure' case. Then, if the issue occurs, the link 'transmq' along with the link data can be dumped for post-analysis. These dump events should be enabled by default since it will only take effect when the failure happens. The same approach is also applied for the faulty case that the validation of protocol message is failed. Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:57 +07:00
trace_tipc_link_bc_ack(l, l->acked, acked, &snd_l->transmq);
/* Skip over packets peer has already acked */
skb_queue_walk(&snd_l->transmq, skb) {
if (more(buf_seqno(skb), l->acked))
break;
}
/* Update/release the packets peer is acking now */
skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
if (more(buf_seqno(skb), acked))
break;
if (!--TIPC_SKB_CB(skb)->ackers) {
__skb_unlink(skb, &snd_l->transmq);
kfree_skb(skb);
}
}
l->acked = acked;
tipc_link_advance_backlog(snd_l, xmitq);
if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
link_prepare_wakeup(snd_l);
}
/* tipc_link_bc_nack_rcv(): receive broadcast nack message
* This function is here for backwards compatibility, since
* no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
*/
int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
struct sk_buff_head *xmitq)
{
struct tipc_msg *hdr = buf_msg(skb);
u32 dnode = msg_destnode(hdr);
int mtyp = msg_type(hdr);
u16 acked = msg_bcast_ack(hdr);
u16 from = acked + 1;
u16 to = msg_bcgap_to(hdr);
u16 peers_snd_nxt = to + 1;
int rc = 0;
kfree_skb(skb);
if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
return 0;
if (mtyp != STATE_MSG)
return 0;
if (dnode == tipc_own_addr(l->net)) {
tipc_link_bc_ack_rcv(l, acked, xmitq);
rc = tipc_link_bc_retrans(l->bc_sndlink, l, from, to, xmitq);
l->stats.recv_nacks++;
return rc;
}
/* Msg for other node => suppress own NACK at next sync if applicable */
if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
l->nack_state = BC_NACK_SND_SUPPRESS;
return 0;
}
tipc: clean up handling of message priorities Messages transferred by TIPC are assigned an "importance priority", -an integer value indicating how to treat the message when there is link or destination socket congestion. There is no separate header field for this value. Instead, the message user values have been chosen in ascending order according to perceived importance, so that the message user field can be used for this. This is not a good solution. First, we have many more users than the needed priority levels, so we end up with treating more priority levels than necessary. Second, the user field cannot always accurately reflect the priority of the message. E.g., a message fragment packet should really have the priority of the enveloped user data message, and not the priority of the MSG_FRAGMENTER user. Until now, we have been working around this problem in different ways, but it is now time to implement a consistent way of handling such priorities, although still within the constraint that we cannot allocate any more bits in the regular data message header for this. In this commit, we define a new priority level, TIPC_SYSTEM_IMPORTANCE, that will be the only one used apart from the four (lower) user data levels. All non-data messages map down to this priority. Furthermore, we take some free bits from the MSG_FRAGMENTER header and allocate them to store the priority of the enveloped message. We then adjust the functions msg_importance()/msg_set_importance() so that they read/set the correct header fields depending on user type. This small protocol change is fully compatible, because the code at the receiving end of a link currently reads the importance level only from user data messages, where there is no change. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-14 03:08:11 +07:00
void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
{
int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE);
tipc: clean up handling of message priorities Messages transferred by TIPC are assigned an "importance priority", -an integer value indicating how to treat the message when there is link or destination socket congestion. There is no separate header field for this value. Instead, the message user values have been chosen in ascending order according to perceived importance, so that the message user field can be used for this. This is not a good solution. First, we have many more users than the needed priority levels, so we end up with treating more priority levels than necessary. Second, the user field cannot always accurately reflect the priority of the message. E.g., a message fragment packet should really have the priority of the enveloped user data message, and not the priority of the MSG_FRAGMENTER user. Until now, we have been working around this problem in different ways, but it is now time to implement a consistent way of handling such priorities, although still within the constraint that we cannot allocate any more bits in the regular data message header for this. In this commit, we define a new priority level, TIPC_SYSTEM_IMPORTANCE, that will be the only one used apart from the four (lower) user data levels. All non-data messages map down to this priority. Furthermore, we take some free bits from the MSG_FRAGMENTER header and allocate them to store the priority of the enveloped message. We then adjust the functions msg_importance()/msg_set_importance() so that they read/set the correct header fields depending on user type. This small protocol change is fully compatible, because the code at the receiving end of a link currently reads the importance level only from user data messages, where there is no change. Reviewed-by: Erik Hugne <erik.hugne@ericsson.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-14 03:08:11 +07:00
l->window = win;
l->backlog[TIPC_LOW_IMPORTANCE].limit = max_t(u16, 50, win);
l->backlog[TIPC_MEDIUM_IMPORTANCE].limit = max_t(u16, 100, win * 2);
l->backlog[TIPC_HIGH_IMPORTANCE].limit = max_t(u16, 150, win * 3);
l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = max_t(u16, 200, win * 4);
l->backlog[TIPC_SYSTEM_IMPORTANCE].limit = max_bulk;
}
/**
* link_reset_stats - reset link statistics
* @l: pointer to link
*/
void tipc_link_reset_stats(struct tipc_link *l)
{
memset(&l->stats, 0, sizeof(l->stats));
}
tipc: introduce node contact FSM The logics for determining when a node is permitted to establish and maintain contact with its peer node becomes non-trivial in the presence of multiple parallel links that may come and go independently. A known failure scenario is that one endpoint registers both its links to the peer lost, cleans up it binding table, and prepares for a table update once contact is re-establihed, while the other endpoint may see its links reset and re-established one by one, hence seeing no need to re-synchronize the binding table. To avoid this, a node must not allow re-establishing contact until it has confirmation that even the peer has lost both links. Currently, the mechanism for handling this consists of setting and resetting two state flags from different locations in the code. This solution is hard to understand and maintain. A closer analysis even reveals that it is not completely safe. In this commit we do instead introduce an FSM that keeps track of the conditions for when the node can establish and maintain links. It has six states and four events, and is strictly based on explicit knowledge about the own node's and the peer node's contact states. Only events leading to state change are shown as edges in the figure below. +--------------+ | SELF_UP/ | +---------------->| PEER_COMING |-----------------+ SELF_ | +--------------+ |PEER_ ESTBL_ | | |ESTBL_ CONTACT| SELF_LOST_CONTACT | |CONTACT | v | | +--------------+ | | PEER_ | SELF_DOWN/ | SELF_ | | LOST_ +--| PEER_LEAVING |<--+ LOST_ v +-------------+ CONTACT | +--------------+ | CONTACT +-----------+ | SELF_DOWN/ |<----------+ +----------| SELF_UP/ | | PEER_DOWN |<----------+ +----------| PEER_UP | +-------------+ SELF_ | +--------------+ | PEER_ +-----------+ | LOST_ +--| SELF_LEAVING/|<--+ LOST_ A | CONTACT | PEER_DOWN | CONTACT | | +--------------+ | | A | PEER_ | PEER_LOST_CONTACT | |SELF_ ESTBL_ | | |ESTBL_ CONTACT| +--------------+ |CONTACT +---------------->| PEER_UP/ |-----------------+ | SELF_COMING | +--------------+ Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-17 03:54:30 +07:00
static void link_print(struct tipc_link *l, const char *str)
{
tipc: introduce node contact FSM The logics for determining when a node is permitted to establish and maintain contact with its peer node becomes non-trivial in the presence of multiple parallel links that may come and go independently. A known failure scenario is that one endpoint registers both its links to the peer lost, cleans up it binding table, and prepares for a table update once contact is re-establihed, while the other endpoint may see its links reset and re-established one by one, hence seeing no need to re-synchronize the binding table. To avoid this, a node must not allow re-establishing contact until it has confirmation that even the peer has lost both links. Currently, the mechanism for handling this consists of setting and resetting two state flags from different locations in the code. This solution is hard to understand and maintain. A closer analysis even reveals that it is not completely safe. In this commit we do instead introduce an FSM that keeps track of the conditions for when the node can establish and maintain links. It has six states and four events, and is strictly based on explicit knowledge about the own node's and the peer node's contact states. Only events leading to state change are shown as edges in the figure below. +--------------+ | SELF_UP/ | +---------------->| PEER_COMING |-----------------+ SELF_ | +--------------+ |PEER_ ESTBL_ | | |ESTBL_ CONTACT| SELF_LOST_CONTACT | |CONTACT | v | | +--------------+ | | PEER_ | SELF_DOWN/ | SELF_ | | LOST_ +--| PEER_LEAVING |<--+ LOST_ v +-------------+ CONTACT | +--------------+ | CONTACT +-----------+ | SELF_DOWN/ |<----------+ +----------| SELF_UP/ | | PEER_DOWN |<----------+ +----------| PEER_UP | +-------------+ SELF_ | +--------------+ | PEER_ +-----------+ | LOST_ +--| SELF_LEAVING/|<--+ LOST_ A | CONTACT | PEER_DOWN | CONTACT | | +--------------+ | | A | PEER_ | PEER_LOST_CONTACT | |SELF_ ESTBL_ | | |ESTBL_ CONTACT| +--------------+ |CONTACT +---------------->| PEER_UP/ |-----------------+ | SELF_COMING | +--------------+ Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-17 03:54:30 +07:00
struct sk_buff *hskb = skb_peek(&l->transmq);
u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
tipc: introduce node contact FSM The logics for determining when a node is permitted to establish and maintain contact with its peer node becomes non-trivial in the presence of multiple parallel links that may come and go independently. A known failure scenario is that one endpoint registers both its links to the peer lost, cleans up it binding table, and prepares for a table update once contact is re-establihed, while the other endpoint may see its links reset and re-established one by one, hence seeing no need to re-synchronize the binding table. To avoid this, a node must not allow re-establishing contact until it has confirmation that even the peer has lost both links. Currently, the mechanism for handling this consists of setting and resetting two state flags from different locations in the code. This solution is hard to understand and maintain. A closer analysis even reveals that it is not completely safe. In this commit we do instead introduce an FSM that keeps track of the conditions for when the node can establish and maintain links. It has six states and four events, and is strictly based on explicit knowledge about the own node's and the peer node's contact states. Only events leading to state change are shown as edges in the figure below. +--------------+ | SELF_UP/ | +---------------->| PEER_COMING |-----------------+ SELF_ | +--------------+ |PEER_ ESTBL_ | | |ESTBL_ CONTACT| SELF_LOST_CONTACT | |CONTACT | v | | +--------------+ | | PEER_ | SELF_DOWN/ | SELF_ | | LOST_ +--| PEER_LEAVING |<--+ LOST_ v +-------------+ CONTACT | +--------------+ | CONTACT +-----------+ | SELF_DOWN/ |<----------+ +----------| SELF_UP/ | | PEER_DOWN |<----------+ +----------| PEER_UP | +-------------+ SELF_ | +--------------+ | PEER_ +-----------+ | LOST_ +--| SELF_LEAVING/|<--+ LOST_ A | CONTACT | PEER_DOWN | CONTACT | | +--------------+ | | A | PEER_ | PEER_LOST_CONTACT | |SELF_ ESTBL_ | | |ESTBL_ CONTACT| +--------------+ |CONTACT +---------------->| PEER_UP/ |-----------------+ | SELF_COMING | +--------------+ Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-17 03:54:30 +07:00
u16 tail = l->snd_nxt - 1;
tipc: merge link->exec_mode and link->state into one FSM Until now, we have been handling link failover and synchronization by using an additional link state variable, "exec_mode". This variable is not independent of the link FSM state, something causing a risk of inconsistencies, apart from the fact that it clutters the code. The conditions are now in place to define a new link FSM that covers all existing use cases, including failover and synchronization, and eliminate the "exec_mode" field altogether. The FSM must also support non-atomic resetting of links, which will be introduced later. The new link FSM is shown below, with 7 states and 8 events. Only events leading to state change are shown as edges. +------------------------------------+ |RESET_EVT | | | | +--------------+ | +-----------------| SYNCHING |-----------------+ | |FAILURE_EVT +--------------+ PEER_RESET_EVT| | | A | | | | | | | | | | | | | | |SYNCH_ |SYNCH_ | | | |BEGIN_EVT |END_EVT | | | | | | | V | V V | +-------------+ +--------------+ +------------+ | | RESETTING |<---------| ESTABLISHED |--------->| PEER_RESET | | +-------------+ FAILURE_ +--------------+ PEER_ +------------+ | | EVT | A RESET_EVT | | | | | | | | | | | | | +--------------+ | | | RESET_EVT| |RESET_EVT |ESTABLISH_EVT | | | | | | | | | | | | V V | | | +-------------+ +--------------+ RESET_EVT| +--->| RESET |--------->| ESTABLISHING |<----------------+ +-------------+ PEER_ +--------------+ | A RESET_EVT | | | | | | | |FAILOVER_ |FAILOVER_ |FAILOVER_ |BEGIN_EVT |END_EVT |BEGIN_EVT | | | V | | +-------------+ | | FAILINGOVER |<----------------+ +-------------+ These changes are fully backwards compatible. Tested-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-31 05:24:21 +07:00
pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
tipc: introduce node contact FSM The logics for determining when a node is permitted to establish and maintain contact with its peer node becomes non-trivial in the presence of multiple parallel links that may come and go independently. A known failure scenario is that one endpoint registers both its links to the peer lost, cleans up it binding table, and prepares for a table update once contact is re-establihed, while the other endpoint may see its links reset and re-established one by one, hence seeing no need to re-synchronize the binding table. To avoid this, a node must not allow re-establishing contact until it has confirmation that even the peer has lost both links. Currently, the mechanism for handling this consists of setting and resetting two state flags from different locations in the code. This solution is hard to understand and maintain. A closer analysis even reveals that it is not completely safe. In this commit we do instead introduce an FSM that keeps track of the conditions for when the node can establish and maintain links. It has six states and four events, and is strictly based on explicit knowledge about the own node's and the peer node's contact states. Only events leading to state change are shown as edges in the figure below. +--------------+ | SELF_UP/ | +---------------->| PEER_COMING |-----------------+ SELF_ | +--------------+ |PEER_ ESTBL_ | | |ESTBL_ CONTACT| SELF_LOST_CONTACT | |CONTACT | v | | +--------------+ | | PEER_ | SELF_DOWN/ | SELF_ | | LOST_ +--| PEER_LEAVING |<--+ LOST_ v +-------------+ CONTACT | +--------------+ | CONTACT +-----------+ | SELF_DOWN/ |<----------+ +----------| SELF_UP/ | | PEER_DOWN |<----------+ +----------| PEER_UP | +-------------+ SELF_ | +--------------+ | PEER_ +-----------+ | LOST_ +--| SELF_LEAVING/|<--+ LOST_ A | CONTACT | PEER_DOWN | CONTACT | | +--------------+ | | A | PEER_ | PEER_LOST_CONTACT | |SELF_ ESTBL_ | | |ESTBL_ CONTACT| +--------------+ |CONTACT +---------------->| PEER_UP/ |-----------------+ | SELF_COMING | +--------------+ Reviewed-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-07-17 03:54:30 +07:00
pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
skb_queue_len(&l->transmq), head, tail,
skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
}
/* Parse and validate nested (link) properties valid for media, bearer and link
*/
int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
{
int err;
netlink: make validation more configurable for future strictness We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 19:07:28 +07:00
err = nla_parse_nested_deprecated(props, TIPC_NLA_PROP_MAX, prop,
tipc_nl_prop_policy, NULL);
if (err)
return err;
if (props[TIPC_NLA_PROP_PRIO]) {
u32 prio;
prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
if (prio > TIPC_MAX_LINK_PRI)
return -EINVAL;
}
if (props[TIPC_NLA_PROP_TOL]) {
u32 tol;
tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
return -EINVAL;
}
if (props[TIPC_NLA_PROP_WIN]) {
u32 win;
win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
return -EINVAL;
}
return 0;
}
static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
{
int i;
struct nlattr *stats;
struct nla_map {
u32 key;
u32 val;
};
struct nla_map map[] = {
{TIPC_NLA_STATS_RX_INFO, 0},
{TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
{TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
{TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
{TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
{TIPC_NLA_STATS_TX_INFO, 0},
{TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
{TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
{TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
{TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
{TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
s->msg_length_counts : 1},
{TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
{TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
{TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
{TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
{TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
{TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
{TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
{TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
{TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
{TIPC_NLA_STATS_RX_STATES, s->recv_states},
{TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
{TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
{TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
{TIPC_NLA_STATS_TX_STATES, s->sent_states},
{TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
{TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
{TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
{TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
{TIPC_NLA_STATS_DUPLICATES, s->duplicates},
{TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
{TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
{TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
(s->accu_queue_sz / s->queue_sz_counts) : 0}
};
stats = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
if (!stats)
return -EMSGSIZE;
for (i = 0; i < ARRAY_SIZE(map); i++)
if (nla_put_u32(skb, map[i].key, map[i].val))
goto msg_full;
nla_nest_end(skb, stats);
return 0;
msg_full:
nla_nest_cancel(skb, stats);
return -EMSGSIZE;
}
/* Caller should hold appropriate locks to protect the link */
int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
struct tipc_link *link, int nlflags)
{
u32 self = tipc_own_addr(net);
struct nlattr *attrs;
struct nlattr *prop;
void *hdr;
int err;
hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
nlflags, TIPC_NL_LINK_GET);
if (!hdr)
return -EMSGSIZE;
attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
if (!attrs)
goto msg_full;
if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
goto attr_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, tipc_cluster_mask(self)))
goto attr_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
goto attr_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
goto attr_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
goto attr_msg_full;
if (tipc_link_is_up(link))
if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
goto attr_msg_full;
if (link->active)
if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
goto attr_msg_full;
prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
if (!prop)
goto attr_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
goto prop_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
goto prop_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
link->window))
goto prop_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
goto prop_msg_full;
nla_nest_end(msg->skb, prop);
err = __tipc_nl_add_stats(msg->skb, &link->stats);
if (err)
goto attr_msg_full;
nla_nest_end(msg->skb, attrs);
genlmsg_end(msg->skb, hdr);
return 0;
prop_msg_full:
nla_nest_cancel(msg->skb, prop);
attr_msg_full:
nla_nest_cancel(msg->skb, attrs);
msg_full:
genlmsg_cancel(msg->skb, hdr);
return -EMSGSIZE;
}
static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
struct tipc_stats *stats)
{
int i;
struct nlattr *nest;
struct nla_map {
__u32 key;
__u32 val;
};
struct nla_map map[] = {
{TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
{TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
{TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
{TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
{TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
{TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
{TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
{TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
{TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
{TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
{TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
{TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
{TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
{TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
{TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
{TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
{TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
{TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
{TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
(stats->accu_queue_sz / stats->queue_sz_counts) : 0}
};
nest = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
if (!nest)
return -EMSGSIZE;
for (i = 0; i < ARRAY_SIZE(map); i++)
if (nla_put_u32(skb, map[i].key, map[i].val))
goto msg_full;
nla_nest_end(skb, nest);
return 0;
msg_full:
nla_nest_cancel(skb, nest);
return -EMSGSIZE;
}
int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
{
int err;
void *hdr;
struct nlattr *attrs;
struct nlattr *prop;
struct tipc_net *tn = net_generic(net, tipc_net_id);
tipc: support broadcast/replicast configurable for bc-link Currently, a multicast stream uses either broadcast or replicast as transmission method, based on the ratio between number of actual destinations nodes and cluster size. However, when an L2 interface (e.g., VXLAN) provides pseudo broadcast support, this becomes very inefficient, as it blindly replicates multicast packets to all cluster/subnet nodes, irrespective of whether they host actual target sockets or not. The TIPC multicast algorithm is able to distinguish real destination nodes from other nodes, and hence provides a smarter and more efficient method for transferring multicast messages than pseudo broadcast can do. Because of this, we now make it possible for users to force the broadcast link to permanently switch to using replicast, irrespective of which capabilities the bearer provides, or pretend to provide. Conversely, we also make it possible to force the broadcast link to always use true broadcast. While maybe less useful in deployed systems, this may at least be useful for testing the broadcast algorithm in small clusters. We retain the current AUTOSELECT ability, i.e., to let the broadcast link automatically select which algorithm to use, and to switch back and forth between broadcast and replicast as the ratio between destination node number and cluster size changes. This remains the default method. Furthermore, we make it possible to configure the threshold ratio for such switches. The default ratio is now set to 10%, down from 25% in the earlier implementation. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-19 18:49:48 +07:00
u32 bc_mode = tipc_bcast_get_broadcast_mode(net);
u32 bc_ratio = tipc_bcast_get_broadcast_ratio(net);
struct tipc_link *bcl = tn->bcl;
if (!bcl)
return 0;
tipc_bcast_lock(net);
hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
NLM_F_MULTI, TIPC_NL_LINK_GET);
if (!hdr) {
tipc_bcast_unlock(net);
return -EMSGSIZE;
}
attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
if (!attrs)
goto msg_full;
/* The broadcast link is always up */
if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
goto attr_msg_full;
if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
goto attr_msg_full;
if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
goto attr_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
goto attr_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
goto attr_msg_full;
prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
if (!prop)
goto attr_msg_full;
if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->window))
goto prop_msg_full;
tipc: support broadcast/replicast configurable for bc-link Currently, a multicast stream uses either broadcast or replicast as transmission method, based on the ratio between number of actual destinations nodes and cluster size. However, when an L2 interface (e.g., VXLAN) provides pseudo broadcast support, this becomes very inefficient, as it blindly replicates multicast packets to all cluster/subnet nodes, irrespective of whether they host actual target sockets or not. The TIPC multicast algorithm is able to distinguish real destination nodes from other nodes, and hence provides a smarter and more efficient method for transferring multicast messages than pseudo broadcast can do. Because of this, we now make it possible for users to force the broadcast link to permanently switch to using replicast, irrespective of which capabilities the bearer provides, or pretend to provide. Conversely, we also make it possible to force the broadcast link to always use true broadcast. While maybe less useful in deployed systems, this may at least be useful for testing the broadcast algorithm in small clusters. We retain the current AUTOSELECT ability, i.e., to let the broadcast link automatically select which algorithm to use, and to switch back and forth between broadcast and replicast as the ratio between destination node number and cluster size changes. This remains the default method. Furthermore, we make it possible to configure the threshold ratio for such switches. The default ratio is now set to 10%, down from 25% in the earlier implementation. Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-19 18:49:48 +07:00
if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST, bc_mode))
goto prop_msg_full;
if (bc_mode & BCLINK_MODE_SEL)
if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST_RATIO,
bc_ratio))
goto prop_msg_full;
nla_nest_end(msg->skb, prop);
err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
if (err)
goto attr_msg_full;
tipc_bcast_unlock(net);
nla_nest_end(msg->skb, attrs);
genlmsg_end(msg->skb, hdr);
return 0;
prop_msg_full:
nla_nest_cancel(msg->skb, prop);
attr_msg_full:
nla_nest_cancel(msg->skb, attrs);
msg_full:
tipc_bcast_unlock(net);
genlmsg_cancel(msg->skb, hdr);
return -EMSGSIZE;
}
void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
struct sk_buff_head *xmitq)
{
l->tolerance = tol;
if (l->bc_rcvlink)
l->bc_rcvlink->tolerance = tol;
if (link_is_up(l))
tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
}
void tipc_link_set_prio(struct tipc_link *l, u32 prio,
struct sk_buff_head *xmitq)
{
l->priority = prio;
tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, prio, xmitq);
}
void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
{
l->abort_limit = limit;
}
tipc: enable tracepoints in tipc As for the sake of debugging/tracing, the commit enables tracepoints in TIPC along with some general trace_events as shown below. It also defines some 'tipc_*_dump()' functions that allow to dump TIPC object data whenever needed, that is, for general debug purposes, ie. not just for the trace_events. The following trace_events are now available: - trace_tipc_skb_dump(): allows to trace and dump TIPC msg & skb data, e.g. message type, user, droppable, skb truesize, cloned skb, etc. - trace_tipc_list_dump(): allows to trace and dump any TIPC buffers or queues, e.g. TIPC link transmq, socket receive queue, etc. - trace_tipc_sk_dump(): allows to trace and dump TIPC socket data, e.g. sk state, sk type, connection type, rmem_alloc, socket queues, etc. - trace_tipc_link_dump(): allows to trace and dump TIPC link data, e.g. link state, silent_intv_cnt, gap, bc_gap, link queues, etc. - trace_tipc_node_dump(): allows to trace and dump TIPC node data, e.g. node state, active links, capabilities, link entries, etc. How to use: Put the trace functions at any places where we want to dump TIPC data or events. Note: a) The dump functions will generate raw data only, that is, to offload the trace event's processing, it can require a tool or script to parse the data but this should be simple. b) The trace_tipc_*_dump() should be reserved for a failure cases only (e.g. the retransmission failure case) or where we do not expect to happen too often, then we can consider enabling these events by default since they will almost not take any effects under normal conditions, but once the rare condition or failure occurs, we get the dumped data fully for post-analysis. For other trace purposes, we can reuse these trace classes as template but different events. c) A trace_event is only effective when we enable it. To enable the TIPC trace_events, echo 1 to 'enable' files in the events/tipc/ directory in the 'debugfs' file system. Normally, they are located at: /sys/kernel/debug/tracing/events/tipc/ For example: To enable the tipc_link_dump event: echo 1 > /sys/kernel/debug/tracing/events/tipc/tipc_link_dump/enable To enable all the TIPC trace_events: echo 1 > /sys/kernel/debug/tracing/events/tipc/enable To collect the trace data: cat trace or cat trace_pipe > /trace.out & To disable all the TIPC trace_events: echo 0 > /sys/kernel/debug/tracing/events/tipc/enable To clear the trace buffer: echo > trace d) Like the other trace_events, the feature like 'filter' or 'trigger' is also usable for the tipc trace_events. For more details, have a look at: Documentation/trace/ftrace.txt MAINTAINERS | add two new files 'trace.h' & 'trace.c' in tipc Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:56 +07:00
char *tipc_link_name_ext(struct tipc_link *l, char *buf)
{
if (!l)
scnprintf(buf, TIPC_MAX_LINK_NAME, "null");
else if (link_is_bc_sndlink(l))
scnprintf(buf, TIPC_MAX_LINK_NAME, "broadcast-sender");
else if (link_is_bc_rcvlink(l))
scnprintf(buf, TIPC_MAX_LINK_NAME,
"broadcast-receiver, peer %x", l->addr);
else
memcpy(buf, l->name, TIPC_MAX_LINK_NAME);
return buf;
}
/**
* tipc_link_dump - dump TIPC link data
* @l: tipc link to be dumped
* @dqueues: bitmask to decide if any link queue to be dumped?
* - TIPC_DUMP_NONE: don't dump link queues
* - TIPC_DUMP_TRANSMQ: dump link transmq queue
* - TIPC_DUMP_BACKLOGQ: dump link backlog queue
* - TIPC_DUMP_DEFERDQ: dump link deferd queue
* - TIPC_DUMP_INPUTQ: dump link input queue
* - TIPC_DUMP_WAKEUP: dump link wakeup queue
* - TIPC_DUMP_ALL: dump all the link queues above
* @buf: returned buffer of dump data in format
*/
int tipc_link_dump(struct tipc_link *l, u16 dqueues, char *buf)
{
int i = 0;
size_t sz = (dqueues) ? LINK_LMAX : LINK_LMIN;
struct sk_buff_head *list;
struct sk_buff *hskb, *tskb;
u32 len;
if (!l) {
i += scnprintf(buf, sz, "link data: (null)\n");
return i;
}
i += scnprintf(buf, sz, "link data: %x", l->addr);
i += scnprintf(buf + i, sz - i, " %x", l->state);
i += scnprintf(buf + i, sz - i, " %u", l->in_session);
i += scnprintf(buf + i, sz - i, " %u", l->session);
i += scnprintf(buf + i, sz - i, " %u", l->peer_session);
i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt);
i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt);
i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt_state);
i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt_state);
i += scnprintf(buf + i, sz - i, " %x", l->peer_caps);
i += scnprintf(buf + i, sz - i, " %u", l->silent_intv_cnt);
i += scnprintf(buf + i, sz - i, " %u", l->rst_cnt);
i += scnprintf(buf + i, sz - i, " %u", l->prev_from);
i += scnprintf(buf + i, sz - i, " %u", 0);
tipc: enable tracepoints in tipc As for the sake of debugging/tracing, the commit enables tracepoints in TIPC along with some general trace_events as shown below. It also defines some 'tipc_*_dump()' functions that allow to dump TIPC object data whenever needed, that is, for general debug purposes, ie. not just for the trace_events. The following trace_events are now available: - trace_tipc_skb_dump(): allows to trace and dump TIPC msg & skb data, e.g. message type, user, droppable, skb truesize, cloned skb, etc. - trace_tipc_list_dump(): allows to trace and dump any TIPC buffers or queues, e.g. TIPC link transmq, socket receive queue, etc. - trace_tipc_sk_dump(): allows to trace and dump TIPC socket data, e.g. sk state, sk type, connection type, rmem_alloc, socket queues, etc. - trace_tipc_link_dump(): allows to trace and dump TIPC link data, e.g. link state, silent_intv_cnt, gap, bc_gap, link queues, etc. - trace_tipc_node_dump(): allows to trace and dump TIPC node data, e.g. node state, active links, capabilities, link entries, etc. How to use: Put the trace functions at any places where we want to dump TIPC data or events. Note: a) The dump functions will generate raw data only, that is, to offload the trace event's processing, it can require a tool or script to parse the data but this should be simple. b) The trace_tipc_*_dump() should be reserved for a failure cases only (e.g. the retransmission failure case) or where we do not expect to happen too often, then we can consider enabling these events by default since they will almost not take any effects under normal conditions, but once the rare condition or failure occurs, we get the dumped data fully for post-analysis. For other trace purposes, we can reuse these trace classes as template but different events. c) A trace_event is only effective when we enable it. To enable the TIPC trace_events, echo 1 to 'enable' files in the events/tipc/ directory in the 'debugfs' file system. Normally, they are located at: /sys/kernel/debug/tracing/events/tipc/ For example: To enable the tipc_link_dump event: echo 1 > /sys/kernel/debug/tracing/events/tipc/tipc_link_dump/enable To enable all the TIPC trace_events: echo 1 > /sys/kernel/debug/tracing/events/tipc/enable To collect the trace data: cat trace or cat trace_pipe > /trace.out & To disable all the TIPC trace_events: echo 0 > /sys/kernel/debug/tracing/events/tipc/enable To clear the trace buffer: echo > trace d) Like the other trace_events, the feature like 'filter' or 'trigger' is also usable for the tipc trace_events. For more details, have a look at: Documentation/trace/ftrace.txt MAINTAINERS | add two new files 'trace.h' & 'trace.c' in tipc Acked-by: Ying Xue <ying.xue@windriver.com> Tested-by: Ying Xue <ying.xue@windriver.com> Acked-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: Tuong Lien <tuong.t.lien@dektech.com.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 09:17:56 +07:00
i += scnprintf(buf + i, sz - i, " %u", l->acked);
list = &l->transmq;
len = skb_queue_len(list);
hskb = skb_peek(list);
tskb = skb_peek_tail(list);
i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
(hskb) ? msg_seqno(buf_msg(hskb)) : 0,
(tskb) ? msg_seqno(buf_msg(tskb)) : 0);
list = &l->deferdq;
len = skb_queue_len(list);
hskb = skb_peek(list);
tskb = skb_peek_tail(list);
i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
(hskb) ? msg_seqno(buf_msg(hskb)) : 0,
(tskb) ? msg_seqno(buf_msg(tskb)) : 0);
list = &l->backlogq;
len = skb_queue_len(list);
hskb = skb_peek(list);
tskb = skb_peek_tail(list);
i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
(hskb) ? msg_seqno(buf_msg(hskb)) : 0,
(tskb) ? msg_seqno(buf_msg(tskb)) : 0);
list = l->inputq;
len = skb_queue_len(list);
hskb = skb_peek(list);
tskb = skb_peek_tail(list);
i += scnprintf(buf + i, sz - i, " | %u %u %u\n", len,
(hskb) ? msg_seqno(buf_msg(hskb)) : 0,
(tskb) ? msg_seqno(buf_msg(tskb)) : 0);
if (dqueues & TIPC_DUMP_TRANSMQ) {
i += scnprintf(buf + i, sz - i, "transmq: ");
i += tipc_list_dump(&l->transmq, false, buf + i);
}
if (dqueues & TIPC_DUMP_BACKLOGQ) {
i += scnprintf(buf + i, sz - i,
"backlogq: <%u %u %u %u %u>, ",
l->backlog[TIPC_LOW_IMPORTANCE].len,
l->backlog[TIPC_MEDIUM_IMPORTANCE].len,
l->backlog[TIPC_HIGH_IMPORTANCE].len,
l->backlog[TIPC_CRITICAL_IMPORTANCE].len,
l->backlog[TIPC_SYSTEM_IMPORTANCE].len);
i += tipc_list_dump(&l->backlogq, false, buf + i);
}
if (dqueues & TIPC_DUMP_DEFERDQ) {
i += scnprintf(buf + i, sz - i, "deferdq: ");
i += tipc_list_dump(&l->deferdq, false, buf + i);
}
if (dqueues & TIPC_DUMP_INPUTQ) {
i += scnprintf(buf + i, sz - i, "inputq: ");
i += tipc_list_dump(l->inputq, false, buf + i);
}
if (dqueues & TIPC_DUMP_WAKEUP) {
i += scnprintf(buf + i, sz - i, "wakeup: ");
i += tipc_list_dump(&l->wakeupq, false, buf + i);
}
return i;
}