linux_dsm_epyc7002/net/tipc/link.c

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/*
* 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"
#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
* @last_retransmitted: sequence number of most recently retransmitted message
* @stale_count: # of identical retransmit requests made by peer
* @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 */
u32 peer_session;
u32 session;
u32 peer_bearer_id;
u32 bearer_id;
u32 tolerance;
u32 abort_limit;
u32 state;
u16 peer_caps;
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;
/* 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 last_retransm;
u16 window;
u32 stale_count;
/* 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;
unsigned long prev_retr;
u16 prev_from;
u16 prev_to;
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_LIMIT 10 /* [ms] */
/*
* Interval between NACKs when packets arrive out of order
*/
#define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
/* Wildcard value for link session numbers. When it is known that
* peer endpoint is down, any session number must be accepted.
*/
#define ANY_SESSION 0x10000
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);
/*
* 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));
}
int tipc_link_is_active(struct tipc_link *l)
{
return l->active;
}
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_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_link_reset(rcv_l);
rcv_l->state = LINK_RESET;
if (!snd_l->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;
}
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;
}
/**
* 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,
int window, u32 session, u32 ownnode, u32 peer,
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)
{
struct tipc_link *l;
l = kzalloc(sizeof(*l), GFP_ATOMIC);
if (!l)
return false;
*link = l;
l->session = session;
/* Note: peer i/f name is completed by reset/activate message */
sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
strcpy(l->if_name, if_name);
l->addr = peer;
l->peer_caps = peer_caps;
l->net = net;
l->peer_session = ANY_SESSION;
l->bearer_id = bearer_id;
l->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->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,
0, ownnode, peer, peer_caps, bc_sndlink,
NULL, inputq, namedq, link))
return false;
l = *link;
strcpy(l->name, tipc_bclink_name);
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;
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: 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);
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_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: 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++;
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
*/
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)
{
l->peer_session = ANY_SESSION;
l->session++;
l->mtu = l->advertised_mtu;
__skb_queue_purge(&l->transmq);
__skb_queue_purge(&l->deferdq);
skb_queue_splice_init(&l->wakeupq, l->inputq);
__skb_queue_purge(&l->backlogq);
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->acked = 0;
l->silent_intv_cnt = 0;
l->rst_cnt = 0;
l->stale_count = 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);
__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;
}
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);
__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;
}
static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)
{
struct tipc_msg *hdr = buf_msg(skb);
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));
}
int tipc_link_retrans(struct tipc_link *l, struct tipc_link *nacker,
u16 from, u16 to, struct sk_buff_head *xmitq)
{
struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
struct tipc_msg *hdr;
u16 ack = l->rcv_nxt - 1;
u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
if (!skb)
return 0;
/* Detect repeated retransmit failures on same packet */
if (nacker->last_retransm != buf_seqno(skb)) {
nacker->last_retransm = buf_seqno(skb);
nacker->stale_count = 1;
} else if (++nacker->stale_count > 100) {
link_retransmit_failure(l, skb);
nacker->stale_count = 0;
if (link_is_bc_sndlink(l))
return TIPC_LINK_DOWN_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 tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
}
/* Move forward to where retransmission should start */
skb_queue_walk(&l->transmq, skb) {
if (!less(buf_seqno(skb), from))
break;
}
skb_queue_walk_from(&l->transmq, skb) {
if (more(buf_seqno(skb), to))
break;
hdr = buf_msg(skb);
_skb = __pskb_copy(skb, 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;
}
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 false;
};
}
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 tipc_msg *hdr = buf_msg(skb);
struct sk_buff **reasm_skb = &l->reasm_buf;
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 rc = 0;
int pos = 0;
int ipos = 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 (unlikely(usr == TUNNEL_PROTOCOL)) {
if (msg_type(hdr) == SYNCH_MSG) {
__skb_queue_purge(&l->deferdq);
goto drop;
}
if (!tipc_msg_extract(skb, &iskb, &ipos))
return rc;
kfree_skb(skb);
skb = iskb;
hdr = buf_msg(skb);
if (less(msg_seqno(hdr), l->drop_point))
goto drop;
if (tipc_data_input(l, skb, inputq))
return rc;
usr = msg_user(hdr);
reasm_skb = &l->failover_reasm_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
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);
}
drop:
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;
}
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_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;
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;
}
if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
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;
struct tipc_msg *hdr;
u16 seqno, rcv_nxt, win_lim;
int rc = 0;
do {
hdr = buf_msg(skb);
seqno = msg_seqno(hdr);
rcv_nxt = l->rcv_nxt;
win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
/* Verify and update link state */
if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
return tipc_link_proto_rcv(l, skb, xmitq);
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;
}
/* Don't send probe at next timeout expiration */
l->silent_intv_cnt = 0;
/* 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 (!tipc_data_input(l, skb, l->inputq))
rc |= tipc_link_input(l, skb, l->inputq);
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;
} while ((skb = __skb_dequeue(defq)));
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;
/* 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: 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
tipc_max_domain_size, 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) {
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: 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
tipc_mon_prep(l->net, data, &dlen, mstate, l->bearer_id);
msg_set_size(hdr, INT_H_SIZE + dlen);
skb_trim(skb, INT_H_SIZE + dlen);
l->stats.sent_states++;
l->rcv_unacked = 0;
} else {
/* RESET_MSG or ACTIVATE_MSG */
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_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 *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);
pktcnt = skb_queue_len(&l->transmq) + 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;
}
}
/* 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);
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: 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;
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: 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:
/* Ignore duplicate RESET with old session number */
if ((less_eq(msg_session(hdr), l->peer_session)) &&
(l->peer_session != ANY_SESSION))
break;
/* fall thru' */
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 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;
/* 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: 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
/* ACTIVATE_MSG serves as PEER_RESET if link is already down */
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
if (msg_peer_stopping(hdr))
rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
else 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 */
if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
rc = TIPC_LINK_UP_EVT;
l->peer_session = msg_session(hdr);
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:
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
/* 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;
/* 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: 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
tipc_mon_rcv(l->net, data, dlen, l->addr,
&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_link_release_pkts(l, ack);
/* If NACK, retransmit will now start at right position */
if (gap) {
rc = tipc_link_retrans(l, l, ack + 1, ack + gap, xmitq);
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;
}
/* link_bc_retr eval()- check if the indicated range can be retransmitted now
* - Adjust permitted range if there is overlap with previous retransmission
*/
static bool link_bc_retr_eval(struct tipc_link *l, u16 *from, u16 *to)
{
unsigned long elapsed = jiffies_to_msecs(jiffies - l->prev_retr);
if (less(*to, *from))
return false;
/* New retransmission request */
if ((elapsed > TIPC_BC_RETR_LIMIT) ||
less(*to, l->prev_from) || more(*from, l->prev_to)) {
l->prev_from = *from;
l->prev_to = *to;
l->prev_retr = jiffies;
return true;
}
/* Inside range of previous retransmit */
if (!less(*from, l->prev_from) && !more(*to, l->prev_to))
return false;
/* Fully or partially outside previous range => exclude overlap */
if (less(*from, l->prev_from)) {
*to = l->prev_from - 1;
l->prev_from = *from;
}
if (more(*to, l->prev_to)) {
*from = l->prev_to + 1;
l->prev_to = *to;
}
l->prev_retr = jiffies;
return true;
}
/* 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;
if (link_bc_retr_eval(snd_l, &from, &to))
rc = tipc_link_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;
/* 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_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_PUBLICATIONS / (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;
err = nla_parse_nested(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(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)
{
int err;
void *hdr;
struct nlattr *attrs;
struct nlattr *prop;
struct tipc_net *tn = net_generic(net, tipc_net_id);
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(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(tn->own_addr)))
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(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(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);
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(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(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;
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;
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;
}