From c77365c963cf8703ecf1004cd3b298068a3e1b76 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sat, 21 Apr 2012 12:31:05 -0400 Subject: [PATCH] NFSv4: Ensure that we don't drop a state owner more than once Retest the RB_EMPTY_NODE() condition under the spin lock to ensure that we don't call rb_erase() more than once on the same state owner. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 3b07f094f3a9..b300fb840b21 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -435,13 +435,17 @@ nfs4_alloc_state_owner(struct nfs_server *server, static void nfs4_drop_state_owner(struct nfs4_state_owner *sp) { - if (!RB_EMPTY_NODE(&sp->so_server_node)) { + struct rb_node *rb_node = &sp->so_server_node; + + if (!RB_EMPTY_NODE(rb_node)) { struct nfs_server *server = sp->so_server; struct nfs_client *clp = server->nfs_client; spin_lock(&clp->cl_lock); - rb_erase(&sp->so_server_node, &server->state_owners); - RB_CLEAR_NODE(&sp->so_server_node); + if (!RB_EMPTY_NODE(rb_node)) { + rb_erase(rb_node, &server->state_owners); + RB_CLEAR_NODE(rb_node); + } spin_unlock(&clp->cl_lock); } }