Commit 1dfd89af authored Apr 21, 2013 by Trond Myklebust

LOCKD: Ensure that nlmclnt_block resets block->b_status after a server reboot



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@us.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@vger.kernel.org

parent 8e472f33

fs/lockd/clntlock.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

fs/lockd/clntproc.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -550,9 +550,6 @@ 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;
		}