mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-25 14:20:52 +07:00
c61dd61dec
In our ongoing effort to simplify the TIPC locking structure,
we see a need to remove the linked list for tipc_links
in the bearer. This can be explained as follows.
Currently, we have three different ways to access a link,
via three different lists/tables:
1: Via a node hash table:
Used by the time-critical outgoing/incoming data paths.
(e.g. link_send_sections_fast() and tipc_recv_msg() ):
grab net_lock(read)
find node from node hash table
grab node_lock
select link
grab bearer_lock
send_msg()
release bearer_lock
release node lock
release net_lock
2: Via a global linked list for nodes:
Used by configuration commands (link_cmd_set_value())
grab net_lock(read)
find node and link from global node list (using link name)
grab node_lock
update link
release node lock
release net_lock
(Same locking order as above. No problem.)
3: Via the bearer's linked link list:
Used by notifications from interface (e.g. tipc_disable_bearer() )
grab net_lock(write)
grab bearer_lock
get link ptr from bearer's link list
get node from link
grab node_lock
delete link
release node lock
release bearer_lock
release net_lock
(Different order from above, but works because we grab the
outer net_lock in write mode first, excluding all other access.)
The first major goal in our simplification effort is to get rid
of the "big" net_lock, replacing it with rcu-locks when accessing
the node list and node hash array. This will come in a later patch
series.
But to get there we first need to rewrite access methods ##2 and 3,
since removal of net_lock would introduce three major problems:
a) In access method #2, we access the link before taking the
protecting node_lock. This will not work once net_lock is gone,
so we will have to change the access order. We will deal with
this in a later commit in this series, "tipc: add node lock
protection to link found by link_find_link()".
b) When the outer protection from net_lock is gone, taking
bearer_lock and node_lock in opposite order of method 1) and 2)
will become an obvious deadlock hazard. This is fixed in the
commit ("tipc: remove bearer_lock from tipc_bearer struct")
later in this series.
c) Similar to what is described in problem a), access method #3
starts with using a link pointer that is unprotected by node_lock,
in order to via that pointer find the correct node struct and
lock it. Before we remove net_lock, this access order must be
altered. This is what we do with this commit.
We can avoid introducing problem problem c) by even here using the
global node list to find the node, before accessing its links. When
we loop though the node list we use the own bearer identity as search
criteria, thus easily finding the links that are associated to the
resetting/disabling bearer. It should be noted that although this
method is somewhat slower than the current list traversal, it is in
no way time critical. This is only about resetting or deleting links,
something that must be considered relatively infrequent events.
As a bonus, we can get rid of the mutual pointers between links and
bearers. After this commit, pointer dependency go in one direction
only: from the link to the bearer.
This commit pre-empts introduction of problem c) as described above.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
198 lines
7.1 KiB
C
198 lines
7.1 KiB
C
/*
|
|
* net/tipc/bearer.h: Include file for TIPC bearer code
|
|
*
|
|
* Copyright (c) 1996-2006, 2013, Ericsson AB
|
|
* Copyright (c) 2005, 2010-2011, 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.
|
|
*/
|
|
|
|
#ifndef _TIPC_BEARER_H
|
|
#define _TIPC_BEARER_H
|
|
|
|
#include "bcast.h"
|
|
|
|
#define MAX_BEARERS 2
|
|
#define MAX_MEDIA 2
|
|
|
|
/*
|
|
* Identifiers associated with TIPC message header media address info
|
|
*
|
|
* - address info field is 20 bytes long
|
|
* - media type identifier located at offset 3
|
|
* - remaining bytes vary according to media type
|
|
*/
|
|
#define TIPC_MEDIA_ADDR_SIZE 20
|
|
#define TIPC_MEDIA_TYPE_OFFSET 3
|
|
|
|
/*
|
|
* Identifiers of supported TIPC media types
|
|
*/
|
|
#define TIPC_MEDIA_TYPE_ETH 1
|
|
#define TIPC_MEDIA_TYPE_IB 2
|
|
|
|
/**
|
|
* struct tipc_media_addr - destination address used by TIPC bearers
|
|
* @value: address info (format defined by media)
|
|
* @media_id: TIPC media type identifier
|
|
* @broadcast: non-zero if address is a broadcast address
|
|
*/
|
|
struct tipc_media_addr {
|
|
u8 value[TIPC_MEDIA_ADDR_SIZE];
|
|
u8 media_id;
|
|
u8 broadcast;
|
|
};
|
|
|
|
struct tipc_bearer;
|
|
|
|
/**
|
|
* struct tipc_media - Media specific info exposed to generic bearer layer
|
|
* @send_msg: routine which handles buffer transmission
|
|
* @enable_media: routine which enables a media
|
|
* @disable_media: routine which disables a media
|
|
* @addr2str: routine which converts media address to string
|
|
* @addr2msg: routine which converts media address to protocol message area
|
|
* @msg2addr: routine which converts media address from protocol message area
|
|
* @priority: default link (and bearer) priority
|
|
* @tolerance: default time (in ms) before declaring link failure
|
|
* @window: default window (in packets) before declaring link congestion
|
|
* @type_id: TIPC media identifier
|
|
* @hwaddr_len: TIPC media address len
|
|
* @name: media name
|
|
*/
|
|
struct tipc_media {
|
|
int (*send_msg)(struct sk_buff *buf,
|
|
struct tipc_bearer *b_ptr,
|
|
struct tipc_media_addr *dest);
|
|
int (*enable_media)(struct tipc_bearer *b_ptr);
|
|
void (*disable_media)(struct tipc_bearer *b_ptr);
|
|
int (*addr2str)(struct tipc_media_addr *a, char *str_buf, int str_size);
|
|
int (*addr2msg)(struct tipc_media_addr *a, char *msg_area);
|
|
int (*msg2addr)(const struct tipc_bearer *b_ptr,
|
|
struct tipc_media_addr *a, char *msg_area);
|
|
u32 priority;
|
|
u32 tolerance;
|
|
u32 window;
|
|
u32 type_id;
|
|
u32 hwaddr_len;
|
|
char name[TIPC_MAX_MEDIA_NAME];
|
|
};
|
|
|
|
/**
|
|
* struct tipc_bearer - Generic TIPC bearer structure
|
|
* @dev: ptr to associated network device
|
|
* @usr_handle: pointer to additional media-specific information about bearer
|
|
* @mtu: max packet size bearer can support
|
|
* @lock: spinlock for controlling access to bearer
|
|
* @addr: media-specific address associated with bearer
|
|
* @name: bearer name (format = media:interface)
|
|
* @media: ptr to media structure associated with bearer
|
|
* @bcast_addr: media address used in broadcasting
|
|
* @priority: default link priority for bearer
|
|
* @window: default window size for bearer
|
|
* @tolerance: default link tolerance for bearer
|
|
* @identity: array index of this bearer within TIPC bearer array
|
|
* @link_req: ptr to (optional) structure making periodic link setup requests
|
|
* @active: non-zero if bearer structure is represents a bearer
|
|
* @net_plane: network plane ('A' through 'H') currently associated with bearer
|
|
* @nodes: indicates which nodes in cluster can be reached through bearer
|
|
*
|
|
* Note: media-specific code is responsible for initialization of the fields
|
|
* indicated below when a bearer is enabled; TIPC's generic bearer code takes
|
|
* care of initializing all other fields.
|
|
*/
|
|
struct tipc_bearer {
|
|
void *media_ptr; /* initalized by media */
|
|
u32 mtu; /* initalized by media */
|
|
struct tipc_media_addr addr; /* initalized by media */
|
|
char name[TIPC_MAX_BEARER_NAME];
|
|
spinlock_t lock;
|
|
struct tipc_media *media;
|
|
struct tipc_media_addr bcast_addr;
|
|
u32 priority;
|
|
u32 window;
|
|
u32 tolerance;
|
|
u32 identity;
|
|
struct tipc_link_req *link_req;
|
|
int active;
|
|
char net_plane;
|
|
struct tipc_node_map nodes;
|
|
};
|
|
|
|
struct tipc_bearer_names {
|
|
char media_name[TIPC_MAX_MEDIA_NAME];
|
|
char if_name[TIPC_MAX_IF_NAME];
|
|
};
|
|
|
|
struct tipc_link;
|
|
|
|
extern struct tipc_bearer tipc_bearers[];
|
|
|
|
/*
|
|
* TIPC routines available to supported media types
|
|
*/
|
|
|
|
void tipc_rcv(struct sk_buff *buf, struct tipc_bearer *tb_ptr);
|
|
int tipc_enable_bearer(const char *bearer_name, u32 disc_domain, u32 priority);
|
|
int tipc_disable_bearer(const char *name);
|
|
|
|
/*
|
|
* Routines made available to TIPC by supported media types
|
|
*/
|
|
extern struct tipc_media eth_media_info;
|
|
|
|
#ifdef CONFIG_TIPC_MEDIA_IB
|
|
extern struct tipc_media ib_media_info;
|
|
#endif
|
|
|
|
int tipc_media_set_priority(const char *name, u32 new_value);
|
|
int tipc_media_set_window(const char *name, u32 new_value);
|
|
void tipc_media_addr_printf(char *buf, int len, struct tipc_media_addr *a);
|
|
struct sk_buff *tipc_media_get_names(void);
|
|
void tipc_l2_media_addr_set(const struct tipc_bearer *b,
|
|
struct tipc_media_addr *a, char *mac);
|
|
int tipc_enable_l2_media(struct tipc_bearer *b);
|
|
void tipc_disable_l2_media(struct tipc_bearer *b);
|
|
int tipc_l2_send_msg(struct sk_buff *buf, struct tipc_bearer *b,
|
|
struct tipc_media_addr *dest);
|
|
|
|
struct sk_buff *tipc_bearer_get_names(void);
|
|
void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest);
|
|
void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest);
|
|
struct tipc_bearer *tipc_bearer_find(const char *name);
|
|
struct tipc_media *tipc_media_find(const char *name);
|
|
int tipc_bearer_setup(void);
|
|
void tipc_bearer_cleanup(void);
|
|
void tipc_bearer_stop(void);
|
|
void tipc_bearer_send(struct tipc_bearer *b, struct sk_buff *buf,
|
|
struct tipc_media_addr *dest);
|
|
|
|
#endif /* _TIPC_BEARER_H */
|