From: Stanislav Kinsbursky <skinsbursky@parallels.com>
Date: Fri, 20 Apr 2012 14:11:02 +0000 (+0400)
Subject: SUNRPC: skip dead but not buried clients on PipeFS events
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a4dff1bc492ee4a2184d384ae8b5bcab5859e150;p=linux-beck.git

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>
---

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;
 	}