[Cluster-devel] [GFS2] Add bh_to_bufdata() function

[Steven Whitehouse]

>From efc837e7d13dd81ea7f9b75919c00e0f98b6ddba Mon Sep 17 00:00:00 2001
From: Steven Whitehouse <swhiteho at redhat.com>
Date: Fri, 30 Nov 2007 14:14:51 +0000
Subject: [PATCH] [GFS2] Add bh_to_bufdata() function

This adds an inline function through which all accesses of
bh->b_private go for journaled data and metadata buffers.
A future patch will update this function so that its more
than just a dereference.

Signed-off-by: Steven Whitehouse <swhiteho at redhat.com>

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 743ebba..4030e30 100644
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -128,6 +128,11 @@ struct gfs2_bufdata {
 	struct list_head bd_ail_gl_list;
 };
 
+static inline struct gfs2_bufdata *bh_to_bufdata(const struct buffer_head *bh)
+{
+	return bh->b_private;
+}
+
 struct gfs2_glock_operations {
 	void (*go_xmote_th) (struct gfs2_glock *gl);
 	void (*go_xmote_bh) (struct gfs2_glock *gl);
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
index 9bece94..7fea147 100644
--- a/fs/gfs2/log.c
+++ b/fs/gfs2/log.c
@@ -504,7 +504,7 @@ struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
 static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate)
 {
 	struct buffer_head *real_bh = bh->b_private;
-	struct gfs2_bufdata *bd = real_bh->b_private;
+	struct gfs2_bufdata *bd = bh_to_bufdata(real_bh);
 	struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd;
 
 	end_buffer_write_sync(bh, uptodate);
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 6b6ae8a..ceae8cf 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -45,7 +45,7 @@ static void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
 		gfs2_assert_withdraw(sdp, 0);
 	if (!buffer_uptodate(bh))
 		gfs2_io_error_bh(sdp, bh);
-	bd = bh->b_private;
+	bd = bh_to_bufdata(bh);
 	/* If this buffer is in the AIL and it has already been written
 	 * to in-place disk block, remove it from the AIL.
 	 */
@@ -66,7 +66,7 @@ static void gfs2_pin(struct gfs2_sbd *sdp, struct buffer_head *bh)
 static void gfs2_unpin(struct gfs2_sbd *sdp, struct buffer_head *bh,
 		       struct gfs2_ail *ai)
 {
-	struct gfs2_bufdata *bd = bh->b_private;
+	struct gfs2_bufdata *bd = bh_to_bufdata(bh);
 	struct gfs2_glock *gl = bd->bd_gl;
 
 	gfs2_assert_withdraw(sdp, buffer_uptodate(bh));
diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
index 9688785..7410514 100644
--- a/fs/gfs2/meta_io.c
+++ b/fs/gfs2/meta_io.c
@@ -277,7 +277,7 @@ void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
 	if (meta)
 		lock_page(bh->b_page);
 
-	if (bh->b_private) {
+	if (bh_to_bufdata(bh)) {
 		if (meta)
 			unlock_page(bh->b_page);
 		return;
@@ -301,7 +301,7 @@ void gfs2_attach_bufdata(struct gfs2_glock *gl, struct buffer_head *bh,
 void gfs2_remove_from_journal(struct buffer_head *bh, struct gfs2_trans *tr, int meta)
 {
 	struct gfs2_sbd *sdp = GFS2_SB(bh->b_page->mapping->host);
-	struct gfs2_bufdata *bd = bh->b_private;
+	struct gfs2_bufdata *bd = bh_to_bufdata(bh);
 	if (test_clear_buffer_pinned(bh)) {
 		atomic_dec(&sdp->sd_log_pinned);
 		list_del_init(&bd->bd_le.le_list);
diff --git a/fs/gfs2/ops_address.c b/fs/gfs2/ops_address.c
index 8f94e30..cf8ef9e 100644
--- a/fs/gfs2/ops_address.c
+++ b/fs/gfs2/ops_address.c
@@ -921,7 +921,7 @@ static void gfs2_discard(struct gfs2_sbd *sdp, struct buffer_head *bh)
 	lock_buffer(bh);
 	gfs2_log_lock(sdp);
 	clear_buffer_dirty(bh);
-	bd = bh->b_private;
+	bd = bh_to_bufdata(bh);
 	if (bd) {
 		if (!list_empty(&bd->bd_le.le_list) && !buffer_pinned(bh))
 			list_del_init(&bd->bd_le.le_list);
@@ -1047,7 +1047,7 @@ int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
 	do {
 		if (atomic_read(&bh->b_count))
 			goto cannot_release;
-		bd = bh->b_private;
+		bd = bh_to_bufdata(bh);
 		if (bd && bd->bd_ail)
 			goto cannot_release;
 		gfs2_assert_warn(sdp, !buffer_pinned(bh));
@@ -1059,7 +1059,7 @@ int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
 	head = bh = page_buffers(page);
 	do {
 		gfs2_log_lock(sdp);
-		bd = bh->b_private;
+		bd = bh_to_bufdata(bh);
 		if (bd) {
 			gfs2_assert_warn(sdp, bd->bd_bh == bh);
 			gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
diff --git a/fs/gfs2/trans.c b/fs/gfs2/trans.c
index cebca7b..c1fdc1d 100644
--- a/fs/gfs2/trans.c
+++ b/fs/gfs2/trans.c
@@ -143,12 +143,12 @@ void gfs2_trans_add_bh(struct gfs2_glock *gl, struct buffer_head *bh, int meta)
 	struct gfs2_sbd *sdp = gl->gl_sbd;
 	struct gfs2_bufdata *bd;
 
-	bd = bh->b_private;
+	bd = bh_to_bufdata(bh);
 	if (bd)
 		gfs2_assert(sdp, bd->bd_gl == gl);
 	else {
 		gfs2_attach_bufdata(gl, bh, meta);
-		bd = bh->b_private;
+		bd = bh_to_bufdata(bh);
 	}
 	lops_add(sdp, &bd->bd_le);
 }
-- 
1.5.1.2