SUNRPC: skip dead but not buried clients on PipeFS events

These clients can't be safely dereferenced if their counter in 0.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 67972462a543..d10ebc4310f7 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -218,7 +218,8 @@ static struct rpc_clnt *rpc_get_client_for_event(struct net *net, int event)
                 if (((event == RPC_PIPEFS_MOUNT) && clnt->cl_dentry) ||
                     ((event == RPC_PIPEFS_UMOUNT) && !clnt->cl_dentry))
                         continue;
-                atomic_inc(&clnt->cl_count);
+                if (atomic_inc_not_zero(&clnt->cl_count) == 0)
+                        continue;
                 spin_unlock(&sn->rpc_client_lock);
                 return clnt;
         }