1 files changed, 8 insertions, 1 deletions

diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index cbf3abe24cdb..54e182a27caf 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -732,14 +732,21 @@ lookup:
         if (tmpres) {
                 int dropping_ref = 0;
 
+                spin_unlock(&dlm->spinlock);
+
                 spin_lock(&tmpres->spinlock);
+                /* We wait for the other thread that is mastering the resource */
+                if (tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN) {
+                        __dlm_wait_on_lockres(tmpres);
+                        BUG_ON(tmpres->owner == DLM_LOCK_RES_OWNER_UNKNOWN);
+                }
+
                 if (tmpres->owner == dlm->node_num) {
                         BUG_ON(tmpres->state & DLM_LOCK_RES_DROPPING_REF);
                         dlm_lockres_grab_inflight_ref(dlm, tmpres);
                 } else if (tmpres->state & DLM_LOCK_RES_DROPPING_REF)
                         dropping_ref = 1;
                 spin_unlock(&tmpres->spinlock);
-                spin_unlock(&dlm->spinlock);
 
                 /* wait until done messaging the master, drop our ref to allow
                  * the lockres to be purged, start over. */