LU-11199 mdt: Attempt lookup lock on open

[fs/lustre-release.git] / lustre / mdt / mdt_open.c

diff --git a/lustre/mdt/mdt_open.c b/lustre/mdt/mdt_open.c
index cc0faf9..28d0656 100644 (file)
--- a/lustre/mdt/mdt_open.c
+++ b/lustre/mdt/mdt_open.c
@@ -909,9 +909,15 @@ static int mdt_object_open_lock(struct mdt_thread_info *info,
 
        mdt_lock_reg_init(lhc, lm);
 
-       /* one problem to return layout lock on open is that it may result
-        * in too many layout locks cached on the client side. */
+       /* Return lookup lock to validate inode at the client side.
+        * This is pretty important otherwise MDT will return layout
+        * lock for each open.
+        * However this is a double-edged sword because changing
+        * permission will revoke a huge number of LOOKUP locks.
+        */
        if (!OBD_FAIL_CHECK(OBD_FAIL_MDS_NO_LL_OPEN) && try_layout) {
+               if (!(*ibits & MDS_INODELOCK_LOOKUP))
+                       trybits |= MDS_INODELOCK_LOOKUP;
                trybits |= MDS_INODELOCK_LAYOUT;
        }