dlm: fix ordering of bast and cast

When both blocking and completion callbacks are queued for lock,
the dlm would always deliver the completion callback (cast) first.
In some cases the blocking callback (bast) is queued before the
cast, though, and should be delivered first.  This patch keeps
track of the order in which they were queued and delivers them
in that order.

This patch also keeps track of the granted mode in the last cast
and eliminates the following bast if the bast mode is compatible
with the preceding cast mode.  This happens when a remotely mastered
lock is demoted, e.g. EX->NL, in which case the local node queues
a cast immediately after sending the demote message.  In this way
a cast can be queued for a mode, e.g. NL, that makes an in-transit
bast extraneous.

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

1 files changed, 6 insertions, 4 deletions

diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index e73a4bb572aa..a4bfd31ac45b 100644
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006-2009 Red Hat, Inc.  All rights reserved.
+ * Copyright (C) 2006-2010 Red Hat, Inc.  All rights reserved.
  *
  * This copyrighted material is made available to anyone wishing to use,
  * modify, copy, or redistribute it subject to the terms and conditions
@@ -173,7 +173,7 @@ static int lkb_is_endoflife(struct dlm_lkb *lkb, int sb_status, int type)
 /* we could possibly check if the cancel of an orphan has resulted in the lkb
    being removed and then remove that lkb from the orphans list and free it */
 
-void dlm_user_add_ast(struct dlm_lkb *lkb, int type, int bastmode)
+void dlm_user_add_ast(struct dlm_lkb *lkb, int type, int mode)
 {
         struct dlm_ls *ls;
         struct dlm_user_args *ua;
@@ -206,8 +206,10 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type, int bastmode)
 
         ast_type = lkb->lkb_ast_type;
         lkb->lkb_ast_type |= type;
-        if (bastmode)
-                lkb->lkb_bastmode = bastmode;
+        if (type == AST_BAST)
+                lkb->lkb_bastmode = mode;
+        else
+                lkb->lkb_castmode = mode;
 
         if (!ast_type) {
                 kref_get(&lkb->lkb_ref);