From 7a2f7d18e79b09c5c5a65fb1fa0e31ad046b3116 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Mon, 21 Apr 2014 10:55:46 +0800 Subject: tipc: decouple the relationship between bearer and link Currently on both paths of message transmission and reception, the read lock of tipc_net_lock must be held before bearer is accessed, while the write lock of tipc_net_lock has to be taken before bearer is configured. Although it can ensure that bearer is always valid on the two data paths, link and bearer is closely bound together. So as the part of effort of removing tipc_net_lock, the locking policy of bearer protection will be adjusted as below: on the two data paths, RCU is used, and on the configuration path of bearer, RTNL lock is applied. Now RCU just covers the path of message reception. To make it possible to protect the path of message transmission with RCU, link should not use its stored bearer pointer to access bearer, but it should use the bearer identity of its attached bearer as index to get bearer instance from bearer_list array, which can help us decouple the relationship between bearer and link. As a result, bearer on the path of message transmission can be safely protected by RCU when we access bearer_list array within RCU lock protection. Signed-off-by: Ying Xue Reviewed-by: Jon Maloy Reviewed-by: Erik Hugne Tested-by: Erik Hugne Signed-off-by: David S. Miller --- net/tipc/link.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net/tipc/link.h') diff --git a/net/tipc/link.h b/net/tipc/link.h index 8c0b49b5b2ee..4b556c181bae 100644 --- a/net/tipc/link.h +++ b/net/tipc/link.h @@ -107,7 +107,7 @@ struct tipc_stats { * @checkpoint: reference point for triggering link continuity checking * @peer_session: link session # being used by peer end of link * @peer_bearer_id: bearer id used by link's peer endpoint - * @b_ptr: pointer to bearer used by link + * @bearer_id: local bearer id used by link * @tolerance: minimum link continuity loss needed to reset link [in ms] * @continuity_interval: link continuity testing interval [in ms] * @abort_limit: # of unacknowledged continuity probes needed to reset link @@ -116,6 +116,7 @@ struct tipc_stats { * @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') * @queue_limit: outbound message queue congestion thresholds (indexed by user) * @exp_msg_count: # of tunnelled messages expected during link changeover * @reset_checkpoint: seq # of last acknowledged message at time of link reset @@ -155,7 +156,7 @@ struct tipc_link { u32 checkpoint; u32 peer_session; u32 peer_bearer_id; - struct tipc_bearer *b_ptr; + u32 bearer_id; u32 tolerance; u32 continuity_interval; u32 abort_limit; @@ -167,6 +168,7 @@ struct tipc_link { } proto_msg; struct tipc_msg *pmsg; u32 priority; + char net_plane; u32 queue_limit[15]; /* queue_limit[0]==window limit */ /* Changeover */ -- cgit v1.2.3