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, 8 insertions, 2 deletions

diff --git a/fs/dlm/dlm_internal.h b/fs/dlm/dlm_internal.h
index 826d3dc6e0ab..f632b58cd222 100644
--- a/fs/dlm/dlm_internal.h
+++ b/fs/dlm/dlm_internal.h
@@ -2,7 +2,7 @@
 *******************************************************************************
 **
 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
-**  Copyright (C) 2004-2008 Red Hat, Inc.  All rights reserved.
+**  Copyright (C) 2004-2010 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
@@ -232,11 +232,17 @@ struct dlm_lkb {
         int8_t                  lkb_status;     /* granted, waiting, convert */
         int8_t                  lkb_rqmode;     /* requested lock mode */
         int8_t                  lkb_grmode;     /* granted lock mode */
-        int8_t                  lkb_bastmode;   /* requested mode */
         int8_t                  lkb_highbast;   /* highest mode bast sent for */
+
         int8_t                  lkb_wait_type;  /* type of reply waiting for */
         int8_t                  lkb_wait_count;
         int8_t                  lkb_ast_type;   /* type of ast queued for */
+        int8_t                  lkb_ast_first;  /* type of first ast queued */
+
+        int8_t                  lkb_bastmode;   /* req mode of queued bast */
+        int8_t                  lkb_castmode;   /* gr mode of queued cast */
+        int8_t                  lkb_bastmode_done; /* last delivered bastmode */
+        int8_t                  lkb_castmode_done; /* last delivered castmode */
 
         struct list_head        lkb_idtbl_list; /* lockspace lkbtbl */
         struct list_head        lkb_statequeue; /* rsb g/c/w list */