[ 23/53] NLM: Ensure that we resend all pending blocking locks after a reclaim

From: Greg Kroah-Hartman
Date: Tue Feb 26 2013 - 19:01:32 EST


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

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

From: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/lockd/clntproc.c | 3 +++
1 file changed, 3 insertions(+)

--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -550,6 +550,9 @@ 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;
}


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