[ 081/104] LOCKD: Ensure that nlmclnt_block resets block->b_status after a server reboot

Greg Kroah-Hartman
2013-05-06T23:21:09Z

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

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@us.ibm.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/lockd/clntlock.c | 3 +++
fs/lockd/clntproc.c | 3 ---
2 files changed, 3 insertions(+), 3 deletions(-)

--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -144,6 +144,9 @@ int nlmclnt_block(struct nlm_wait *block
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;
}
--- a/fs/lockd/clntproc.c
+++ b/fs/lockd/clntproc.c
@@ -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;
}