ocfs2: remove an overly aggressive BUG() in dlmfs
Don't BUG() user_dlm_unblock_lock() on the absence of the USER_LOCK_BLOCKED
flag - this turns out to be a valid case. Make some of the related BUG()
statements print more useful information.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/dlm/userdlm.c b/fs/ocfs2/dlm/userdlm.c
index c3764f4..bac4615 100644
--- a/fs/ocfs2/dlm/userdlm.c
+++ b/fs/ocfs2/dlm/userdlm.c
@@ -268,13 +268,26 @@
spin_lock(&lockres->l_lock);
- BUG_ON(!(lockres->l_flags & USER_LOCK_BLOCKED));
- BUG_ON(!(lockres->l_flags & USER_LOCK_QUEUED));
+ mlog_bug_on_msg(!(lockres->l_flags & USER_LOCK_QUEUED),
+ "Lockres %s, flags 0x%x\n",
+ lockres->l_name, lockres->l_flags);
- /* notice that we don't clear USER_LOCK_BLOCKED here. That's
- * for user_ast to do. */
+ /* notice that we don't clear USER_LOCK_BLOCKED here. If it's
+ * set, we want user_ast clear it. */
lockres->l_flags &= ~USER_LOCK_QUEUED;
+ /* It's valid to get here and no longer be blocked - if we get
+ * several basts in a row, we might be queued by the first
+ * one, the unblock thread might run and clear the queued
+ * flag, and finally we might get another bast which re-queues
+ * us before our ast for the downconvert is called. */
+ if (!(lockres->l_flags & USER_LOCK_BLOCKED)) {
+ mlog(0, "Lockres %s, flags 0x%x: queued but not blocking\n",
+ lockres->l_name, lockres->l_flags);
+ spin_unlock(&lockres->l_lock);
+ goto drop_ref;
+ }
+
if (lockres->l_flags & USER_LOCK_IN_TEARDOWN) {
mlog(0, "lock is in teardown so we do nothing\n");
spin_unlock(&lockres->l_lock);