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

2 files changed, 3 insertions, 3 deletions

diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index 0796c45d0d4d..01bfe7662751 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 7e529c3c45c0..9760ecb9b60f 100644
--- 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;
         }