ocfs2: Remove overzealous BUG_ON during blocked lock processing

During blocked lock processing, we should consider the possibility that the
lock is no longer blocking.

Joel Becker <joel.becker@oracle.com> assisted in fixing this issue.

Reported-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 10 insertions, 2 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index ac24f49ae2fb..ce8e061c9a22 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -3392,9 +3392,17 @@ static int ocfs2_unblock_lock(struct ocfs2_super *osb,
 
         spin_lock_irqsave(&lockres->l_lock, flags);
 
-        BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
-
 recheck:
+        /*
+         * Is it still blocking? If not, we have no more work to do.
+         */
+        if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) {
+                BUG_ON(lockres->l_blocking != DLM_LOCK_NL);
+                spin_unlock_irqrestore(&lockres->l_lock, flags);
+                ret = 0;
+                goto leave;
+        }
+
         if (lockres->l_flags & OCFS2_LOCK_BUSY) {
                 /* XXX
                  * This is a *big* race.  The OCFS2_LOCK_PENDING flag