[PATCH 066/139] NLM: Ensure that we resend all pending blocking locks after a reclaim

[Luis Henriques]

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

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

From: Trond Myklebust <Trond.Myklebust at netapp.com>

commit 666b3d803a511fbc9bc5e5ea8ce66010cf03ea13 upstream.

Currently, nlmclnt_lock will break out of the for(;;) loop when
the reclaimer wakes up the blocking lock thread by setting
nlm_lck_denied_grace_period. This causes the lock request to fail
with an ENOLCK error.
The intention was always to ensure that we resend the lock request
after the grace period has expired.

Reported-by: Wangyuan Zhang <Wangyuan.Zhang at netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust at netapp.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/lockd/clntproc.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index 8392cb8..a3a0987 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -551,6 +551,9 @@ again:
 		status = nlmclnt_block(block, req, NLMCLNT_POLL_TIMEOUT);
 		if (status < 0)
 			break;
+		/* Resend the blocking lock request after a server reboot */
+		if (resp->status ==  nlm_lck_denied_grace_period)
+			continue;
 		if (resp->status != nlm_lck_blocked)
 			break;
 	}
-- 
1.8.1.2