ocfs2/dlm: make existing convertion precedent over new lock

Make existing convertion precedent over new lock. It makes o2dlm locking more
like fair locking.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/ocfs2/dlm/dlmlock.c b/fs/ocfs2/dlm/dlmlock.c
index 69cf369961c4..7009292aac5a 100644
--- a/fs/ocfs2/dlm/dlmlock.c
+++ b/fs/ocfs2/dlm/dlmlock.c
@@ -106,6 +106,9 @@ static int dlm_can_grant_new_lock(struct dlm_lock_resource *res,
 
                 if (!dlm_lock_compatible(tmplock->ml.type, lock->ml.type))
                         return 0;
+                if (!dlm_lock_compatible(tmplock->ml.convert_type,
+                                         lock->ml.type))
+                        return 0;
         }
 
         return 1;