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>

diff --git a/fs/dlm/ast.c b/fs/dlm/ast.c
index 09b167d..fbe840d 100644 (file)
--- 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 */

diff --git a/fs/dlm/ast.h b/fs/dlm/ast.h
index 6ee276c..1b5fc5f 100644 (file)
--- a/fs/dlm/ast.h
+++ b/fs/dlm/ast.h
@@ -1,7 +1,7 @@
 /******************************************************************************
 *******************************************************************************
 **
-**  Copyright (C) 2005 Red Hat, Inc.  All rights reserved.
+**  Copyright (C) 2005-2008 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
@@ -13,7 +13,7 @@
 #ifndef __ASTD_DOT_H__
 #define __ASTD_DOT_H__
 
-void dlm_add_ast(struct dlm_lkb *lkb, int type);
+void dlm_add_ast(struct dlm_lkb *lkb, int type, int bastmode);
 void dlm_del_ast(struct dlm_lkb *lkb);
 
 void dlm_astd_wake(void);

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 724ddac..7b758da 100644 (file)
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -307,7 +307,7 @@ static void queue_cast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rv)
        lkb->lkb_lksb->sb_status = rv;
        lkb->lkb_lksb->sb_flags = lkb->lkb_sbflags;
 
-       dlm_add_ast(lkb, AST_COMP);
+       dlm_add_ast(lkb, AST_COMP, 0);
 }
 
 static inline void queue_cast_overlap(struct dlm_rsb *r, struct dlm_lkb *lkb)
@@ -320,10 +320,8 @@ static void queue_bast(struct dlm_rsb *r, struct dlm_lkb *lkb, int rqmode)
 {
        if (is_master_copy(lkb))
                send_bast(r, lkb, rqmode);
-       else {
-               lkb->lkb_bastmode = rqmode;
-               dlm_add_ast(lkb, AST_BAST);
-       }
+       else
+               dlm_add_ast(lkb, AST_BAST, rqmode);
 }
 
 /*

diff --git a/fs/dlm/user.c b/fs/dlm/user.c
index b3832c6..065149e 100644 (file)
--- a/fs/dlm/user.c
+++ b/fs/dlm/user.c
@@ -175,7 +175,7 @@ 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)
+void dlm_user_add_ast(struct dlm_lkb *lkb, int type, int bastmode)
 {
        struct dlm_ls *ls;
        struct dlm_user_args *ua;
@@ -208,6 +208,8 @@ void dlm_user_add_ast(struct dlm_lkb *lkb, int type)
 
        ast_type = lkb->lkb_ast_type;
        lkb->lkb_ast_type |= type;
+       if (bastmode)
+               lkb->lkb_bastmode = bastmode;
 
        if (!ast_type) {
                kref_get(&lkb->lkb_ref);

diff --git a/fs/dlm/user.h b/fs/dlm/user.h
index 35eb6a1..1c96864 100644 (file)
--- a/fs/dlm/user.h
+++ b/fs/dlm/user.h
@@ -9,7 +9,7 @@
 #ifndef __USER_DOT_H__
 #define __USER_DOT_H__
 
-void dlm_user_add_ast(struct dlm_lkb *lkb, int type);
+void dlm_user_add_ast(struct dlm_lkb *lkb, int type, int bastmode);
 int dlm_user_init(void);
 void dlm_user_exit(void);
 int dlm_device_deregister(struct dlm_ls *ls);