dlm: reject normal unlock when lock is waiting for lookup

Non-forced unlocks should be rejected if the lock is waiting on the
rsb_lookup list for another lock to establish the master node.

Signed-off-by: David Teigland <teigland@redhat.com>

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index c2890ef..fa68e9b 100644 (file)
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -2110,17 +2110,18 @@ static int validate_unlock_args(struct dlm_lkb *lkb, struct dlm_args *args)
        /* an lkb may be waiting for an rsb lookup to complete where the
           lookup was initiated by another lock */
 
-       if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) {
-               if (!list_empty(&lkb->lkb_rsb_lookup)) {
+       if (!list_empty(&lkb->lkb_rsb_lookup)) {
+               if (args->flags & (DLM_LKF_CANCEL | DLM_LKF_FORCEUNLOCK)) {
                        log_debug(ls, "unlock on rsb_lookup %x", lkb->lkb_id);
                        list_del_init(&lkb->lkb_rsb_lookup);
                        queue_cast(lkb->lkb_resource, lkb,
                                   args->flags & DLM_LKF_CANCEL ?
                                   -DLM_ECANCEL : -DLM_EUNLOCK);
                        unhold_lkb(lkb); /* undoes create_lkb() */
-                       rv = -EBUSY;
-                       goto out;
                }
+               /* caller changes -EBUSY to 0 for CANCEL and FORCEUNLOCK */
+               rv = -EBUSY;
+               goto out;
        }
 
        /* cancel not allowed with another cancel/unlock in progress */