[PATCH 3.11 049/144] NFSv4: nfs4_stateid_is_current should return 'true' for an invalid stateid

[Luis Henriques]

3.11.10.7 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Trond Myklebust <trond.myklebust at primarydata.com>

commit e1253be0ece1a95a02c7f5843194877471af8179 upstream.

When nfs4_set_rw_stateid() can fails by returning EIO to indicate that
the stateid is completely invalid, then it makes no sense to have it
trigger a retry of the READ or WRITE operation. Instead, we should just
have it fall through and attempt a recovery.

This fixes an infinite loop in which the client keeps replaying the same
bad stateid back to the server.

Reported-by: Andy Adamson <andros at netapp.com>
Link: http://lkml.kernel.org/r/1393954269-3974-1-git-send-email-andros@netapp.com
Signed-off-by: Trond Myklebust <trond.myklebust at primarydata.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/nfs/nfs4proc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 64dd7c6..7690917 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -3825,8 +3825,9 @@ static bool nfs4_stateid_is_current(nfs4_stateid *stateid,
 {
 	nfs4_stateid current_stateid;
 
-	if (nfs4_set_rw_stateid(&current_stateid, ctx, l_ctx, fmode))
-		return false;
+	/* If the current stateid represents a lost lock, then exit */
+	if (nfs4_set_rw_stateid(&current_stateid, ctx, l_ctx, fmode) == -EIO)
+		return true;
 	return nfs4_stateid_match(stateid, &current_stateid);
 }
 
-- 
1.9.1