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>

1 files changed, 5 insertions, 4 deletions

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index c2890efb0259..fa68e9b93651 100644
--- 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 */