From f8322dfce5766c8e26d9224cbcaf6fdc0b2eb04d Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Mon, 21 Apr 2014 10:55:45 +0800 Subject: [PATCH] tipc: convert bearer_list to RCU list Convert bearer_list to RCU list. It's protected by RTNL lock on update side, and RCU read lock is applied to read side. 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/bcast.c | 9 ++++++--- net/tipc/bearer.c | 18 +++++++++--------- net/tipc/bearer.h | 4 +++- 3 files changed, 18 insertions(+), 13 deletions(-) diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c index 95ab5ef92920..223a19929024 100644 --- a/net/tipc/bcast.c +++ b/net/tipc/bcast.c @@ -659,6 +659,7 @@ void tipc_bcbearer_sort(void) { struct tipc_bcbearer_pair *bp_temp = bcbearer->bpairs_temp; struct tipc_bcbearer_pair *bp_curr; + struct tipc_bearer *b; int b_index; int pri; @@ -667,8 +668,9 @@ void tipc_bcbearer_sort(void) /* Group bearers by priority (can assume max of two per priority) */ memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp)); + rcu_read_lock(); for (b_index = 0; b_index < MAX_BEARERS; b_index++) { - struct tipc_bearer *b = bearer_list[b_index]; + b = rcu_dereference_rtnl(bearer_list[b_index]); if (!b || !b->nodes.count) continue; @@ -677,6 +679,7 @@ void tipc_bcbearer_sort(void) else bp_temp[b->priority].secondary = b; } + rcu_read_unlock(); /* Create array of bearer pairs for broadcasting */ bp_curr = bcbearer->bpairs; @@ -784,7 +787,7 @@ void tipc_bclink_init(void) bcl->max_pkt = MAX_PKT_DEFAULT_MCAST; tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT); bcl->b_ptr = &bcbearer->bearer; - bearer_list[BCBEARER] = &bcbearer->bearer; + rcu_assign_pointer(bearer_list[MAX_BEARERS], &bcbearer->bearer); bcl->state = WORKING_WORKING; strlcpy(bcl->name, tipc_bclink_name, TIPC_MAX_LINK_NAME); } @@ -795,7 +798,7 @@ void tipc_bclink_stop(void) tipc_link_purge_queues(bcl); spin_unlock_bh(&bc_lock); - bearer_list[BCBEARER] = NULL; + RCU_INIT_POINTER(bearer_list[BCBEARER], NULL); memset(bclink, 0, sizeof(*bclink)); memset(bcbearer, 0, sizeof(*bcbearer)); } diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c index dfb4c7fe4865..65b17639e43d 100644 --- a/net/tipc/bearer.c +++ b/net/tipc/bearer.c @@ -49,7 +49,7 @@ static struct tipc_media * const media_info_array[] = { NULL }; -struct tipc_bearer *bearer_list[MAX_BEARERS + 1]; +struct tipc_bearer __rcu *bearer_list[MAX_BEARERS + 1]; static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down); @@ -178,7 +178,7 @@ struct tipc_bearer *tipc_bearer_find(const char *name) u32 i; for (i = 0; i < MAX_BEARERS; i++) { - b_ptr = bearer_list[i]; + b_ptr = rtnl_dereference(bearer_list[i]); if (b_ptr && (!strcmp(b_ptr->name, name))) return b_ptr; } @@ -201,7 +201,7 @@ struct sk_buff *tipc_bearer_get_names(void) read_lock_bh(&tipc_net_lock); for (i = 0; media_info_array[i] != NULL; i++) { for (j = 0; j < MAX_BEARERS; j++) { - b = bearer_list[j]; + b = rtnl_dereference(bearer_list[j]); if (!b) continue; if (b->media == media_info_array[i]) { @@ -287,7 +287,7 @@ restart: bearer_id = MAX_BEARERS; with_this_prio = 1; for (i = MAX_BEARERS; i-- != 0; ) { - b_ptr = bearer_list[i]; + b_ptr = rtnl_dereference(bearer_list[i]); if (!b_ptr) { bearer_id = i; continue; @@ -344,7 +344,7 @@ restart: goto exit; } - bearer_list[bearer_id] = b_ptr; + rcu_assign_pointer(bearer_list[bearer_id], b_ptr); pr_info("Enabled bearer <%s>, discovery domain %s, priority %u\n", name, @@ -385,12 +385,12 @@ static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down) tipc_disc_delete(b_ptr->link_req); for (i = 0; i < MAX_BEARERS; i++) { - if (b_ptr == bearer_list[i]) { - bearer_list[i] = NULL; + if (b_ptr == rtnl_dereference(bearer_list[i])) { + RCU_INIT_POINTER(bearer_list[i], NULL); break; } } - kfree(b_ptr); + kfree_rcu(b_ptr, rcu); } int tipc_disable_bearer(const char *name) @@ -628,7 +628,7 @@ void tipc_bearer_stop(void) u32 i; for (i = 0; i < MAX_BEARERS; i++) { - b_ptr = bearer_list[i]; + b_ptr = rtnl_dereference(bearer_list[i]); if (b_ptr) { bearer_disable(b_ptr, true); bearer_list[i] = NULL; diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h index ba48145e871d..b67b7ea4cc36 100644 --- a/net/tipc/bearer.h +++ b/net/tipc/bearer.h @@ -113,6 +113,7 @@ struct tipc_media { * @name: bearer name (format = media:interface) * @media: ptr to media structure associated with bearer * @bcast_addr: media address used in broadcasting + * @rcu: rcu struct for tipc_bearer * @priority: default link priority for bearer * @window: default window size for bearer * @tolerance: default link tolerance for bearer @@ -133,6 +134,7 @@ struct tipc_bearer { char name[TIPC_MAX_BEARER_NAME]; struct tipc_media *media; struct tipc_media_addr bcast_addr; + struct rcu_head rcu; u32 priority; u32 window; u32 tolerance; @@ -150,7 +152,7 @@ struct tipc_bearer_names { struct tipc_link; -extern struct tipc_bearer *bearer_list[]; +extern struct tipc_bearer __rcu *bearer_list[]; /* * TIPC routines available to supported media types -- 2.20.1