From eab8c045732635e3833a5d58b17c6da08ff71f9e Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Mon, 28 Apr 2014 18:00:10 +0800 Subject: tipc: move the delivery of named messages out of nametbl lock Commit a89778d8baf19cd7e728d81121a294a06cedaad1 ("tipc: add support for link state subscriptions") introduced below possible deadlock scenario: CPU0 CPU1 T0: tipc_publish() link_timeout() T1: tipc_nametbl_publish() [grab node lock]* T2: [grab nametbl write lock]* link_state_event() T3: named_cluster_distribute() link_activate() T4: [grab node lock]* tipc_node_link_up() T5: tipc_nametbl_publish() T6: [grab nametble write lock]* The opposite order of holding nametbl write lock and node lock on above two different paths may result in a deadlock. If we move the the delivery of named messages via link out of name nametbl lock, the reverse order of holding locks will be eliminated, as a result, the deadlock will be killed as well. Signed-off-by: Ying Xue Reviewed-by: Erik Hugne Signed-off-by: David S. Miller --- net/tipc/name_distr.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/tipc/name_distr.h') diff --git a/net/tipc/name_distr.h b/net/tipc/name_distr.h index 9b312ccfd43e..47ff829f9361 100644 --- a/net/tipc/name_distr.h +++ b/net/tipc/name_distr.h @@ -39,8 +39,9 @@ #include "name_table.h" -void tipc_named_publish(struct publication *publ); -void tipc_named_withdraw(struct publication *publ); +struct sk_buff *tipc_named_publish(struct publication *publ); +struct sk_buff *tipc_named_withdraw(struct publication *publ); +void named_cluster_distribute(struct sk_buff *buf); void tipc_named_node_up(unsigned long node); void tipc_named_rcv(struct sk_buff *buf); void tipc_named_reinit(void); -- cgit