dlm: improve how bast mode handling

The lkb bastmode value is set in the context of processing the
lock, and read by the dlm_astd thread.  Because it's accessed
in these two separate contexts, the writing/reading ought to
be done under a lock.  This is simple to do by setting it and
reading it when the lkb is added to and removed from dlm_astd's
callback list which is properly locked.

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

1 files changed, 8 insertions, 6 deletions

diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index 09b167d..fbe840d 100644
--- a/fs/dlm/ast.c
+++ b/fs/dlm/ast.c
@@ -2,7 +2,7 @@
 *******************************************************************************
 **
 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
-**  Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
+**  Copyright (C) 2004-2008 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
@@ -33,10 +33,10 @@ void dlm_del_ast(struct dlm_lkb *lkb)
 	spin_unlock(&ast_queue_lock);
 }
 
-void dlm_add_ast(struct dlm_lkb *lkb, int type)
+void dlm_add_ast(struct dlm_lkb *lkb, int type, int bastmode)
 {
 	if (lkb->lkb_flags & DLM_IFL_USER) {
-		dlm_user_add_ast(lkb, type);
+		dlm_user_add_ast(lkb, type, bastmode);
 		return;
 	}
 
@@ -46,6 +46,8 @@ void dlm_add_ast(struct dlm_lkb *lkb, int type)
 		list_add_tail(&lkb->lkb_astqueue, &ast_queue);
 	}
 	lkb->lkb_ast_type |= type;
+	if (bastmode)
+		lkb->lkb_bastmode = bastmode;
 	spin_unlock(&ast_queue_lock);
 
 	set_bit(WAKE_ASTS, &astd_wakeflags);
@@ -59,7 +61,7 @@ static void process_asts(void)
 	struct dlm_lkb *lkb;
 	void (*cast) (void *astparam);
 	void (*bast) (void *astparam, int mode);
-	int type = 0, found, bmode;
+	int type = 0, found, bastmode;
 
 	for (;;) {
 		found = 0;
@@ -74,6 +76,7 @@ static void process_asts(void)
 			list_del(&lkb->lkb_astqueue);
 			type = lkb->lkb_ast_type;
 			lkb->lkb_ast_type = 0;
+			bastmode = lkb->lkb_bastmode;
 			found = 1;
 			break;
 		}
@@ -84,13 +87,12 @@ static void process_asts(void)
 
 		cast = lkb->lkb_astfn;
 		bast = lkb->lkb_bastfn;
-		bmode = lkb->lkb_bastmode;
 
 		if ((type & AST_COMP) && cast)
 			cast(lkb->lkb_astparam);
 
 		if ((type & AST_BAST) && bast)
-			bast(lkb->lkb_astparam, bmode);
+			bast(lkb->lkb_astparam, bastmode);
 
 		/* this removes the reference added by dlm_add_ast
 		   and may result in the lkb being freed */