dlm: fix QUECVT when convert queue is empty

The QUECVT flag should not prevent conversions from
being granted immediately when the convert queue is
empty.

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

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index fa5c07d51dccf2cb1b66d4b2d04a4eec8a92e7da..4c58d4a3adc4f29c6a2829bc54ac4be122c77ae7 100644 (file)
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -1736,6 +1736,18 @@ static int _can_be_granted(struct dlm_rsb *r, struct dlm_lkb *lkb, int now)
        if (now && conv && !(lkb->lkb_exflags & DLM_LKF_QUECVT))
                return 1;
 
+       /*
+        * Even if the convert is compat with all granted locks,
+        * QUECVT forces it behind other locks on the convert queue.
+        */
+
+       if (now && conv && (lkb->lkb_exflags & DLM_LKF_QUECVT)) {
+               if (list_empty(&r->res_convertqueue))
+                       return 1;
+               else
+                       goto out;
+       }
+
        /*
         * The NOORDER flag is set to avoid the standard vms rules on grant
         * order.