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authorTrond Myklebust <Trond.Myklebust@netapp.com>2012-04-21 12:31:05 -0400
committerTrond Myklebust <Trond.Myklebust@netapp.com>2012-04-21 12:31:05 -0400
commitc77365c963cf8703ecf1004cd3b298068a3e1b76 (patch)
tree449a02a25c425148a52c5bec073787902ad86fed
parent95b72eb0bdef6476b7e73061f0382adf46c5495a (diff)
downloadlinux-2.6-c77365c963cf8703ecf1004cd3b298068a3e1b76.tar.gz
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 <Trond.Myklebust@netapp.com>
-rw-r--r--fs/nfs/nfs4state.c10
1 files changed, 7 insertions, 3 deletions
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 3b07f094f3a92..b300fb840b216 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);
}
}