[ 3.5.y.z extended stable ] Patch "LOCKD: Ensure that nlmclnt_block resets block->b_status after" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    LOCKD: Ensure that nlmclnt_block resets block->b_status after

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From bb6b9104366e5aad93c24cdca78f82845bc9c00a Mon Sep 17 00:00:00 2001
From: Trond Myklebust <Trond.Myklebust at netapp.com>
Date: Sun, 21 Apr 2013 18:01:06 -0400
Subject: [PATCH] LOCKD: Ensure that nlmclnt_block resets block->b_status after
 a server reboot

commit 1dfd89af8697a299e7982ae740d4695ecd917eef upstream.

After a server reboot, the reclaimer thread will recover all the existing
locks. For locks that are blocked, however, it will change the value
of block->b_status to nlm_lck_denied_grace_period in order to signal that
they need to wake up and resend the original blocking lock request.

Due to a bug, however, the block->b_status never gets reset after the
blocked locks have been woken up, and so the process goes into an
infinite loop of resends until the blocked lock is satisfied.

Reported-by: Marc Eshel <eshel at us.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust at netapp.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/lockd/clntlock.c | 3 +++
 fs/lockd/clntproc.c | 3 ---
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index ca0a080..193f04c 100644
--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -144,6 +144,9 @@ int nlmclnt_block(struct nlm_wait *block, struct nlm_rqst *req, long timeout)
 			timeout);
 	if (ret < 0)
 		return -ERESTARTSYS;
+	/* Reset the lock status after a server reboot so we resend */
+	if (block->b_status == nlm_lck_denied_grace_period)
+		block->b_status = nlm_lck_blocked;
 	req->a_res.status = block->b_status;
 	return 0;
 }
diff --git a/fs/lockd/clntproc.c b/fs/lockd/clntproc.c
index a3a0987..8392cb8 100644
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -551,9 +551,6 @@ 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