[GFS2] Remove uneeded endian conversion

In many places GFS2 was calling the endian conversion routines
for an inode even when only a single field, or a few fields might
have changed. As a result we were copying lots of data needlessly.

This patch replaces those calls with conversion of just the
required fields in each case. This should be faster and easier
to understand. There are still other places which suffer from this
problem, but this is a start in the right direction.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/bmap.c

@@ -121,6 +121,7 @@ static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
 int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page)
 {
 	struct buffer_head *bh, *dibh;
+	struct gfs2_dinode *di;
 	u64 block = 0;
 	int isdir = gfs2_is_dir(ip);
 	int error;
@@ -141,8 +142,7 @@ int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page)
 			error = gfs2_dir_get_new_buffer(ip, block, &bh);
 			if (error)
 				goto out_brelse;
-			gfs2_buffer_copy_tail(bh,
-					      sizeof(struct gfs2_meta_header),
+			gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_meta_header),
 					      dibh, sizeof(struct gfs2_dinode));
 			brelse(bh);
 		} else {
@@ -157,18 +157,17 @@ int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page)
 	/*  Set up the pointer to the new block  */
 
 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
-
+	di = (struct gfs2_dinode *)dibh->b_data;
 	gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
 
 	if (ip->i_di.di_size) {
-		*(u64 *)(dibh->b_data + sizeof(struct gfs2_dinode)) =
-			cpu_to_be64(block);
+		*(__be64 *)(di + 1) = cpu_to_be64(block);
 		ip->i_di.di_blocks++;
+		di->di_blocks = cpu_to_be64(ip->i_di.di_blocks);
 	}
 
 	ip->i_di.di_height = 1;
-
-	gfs2_dinode_out(&ip->i_di, dibh->b_data);
+	di->di_height = cpu_to_be16(1);
 
 out_brelse:
 	brelse(dibh);
@@ -229,6 +228,7 @@ static int build_height(struct inode *inode, unsigned height)
 	unsigned new_height = height - ip->i_di.di_height;
 	struct buffer_head *dibh;
 	struct buffer_head *blocks[GFS2_MAX_META_HEIGHT];
+	struct gfs2_dinode *di;
 	int error;
 	u64 *bp;
 	u64 bn;
@@ -267,12 +267,13 @@ static int build_height(struct inode *inode, unsigned height)
 			      dibh, sizeof(struct gfs2_dinode));
 	brelse(blocks[n]);
 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+	di = (struct gfs2_dinode *)dibh->b_data;
 	gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode));
-	bp = (u64 *)(dibh->b_data + sizeof(struct gfs2_dinode));
-	*bp = cpu_to_be64(bn);
+	*(__be64 *)(di + 1) = cpu_to_be64(bn);
 	ip->i_di.di_height += new_height;
 	ip->i_di.di_blocks += new_height;
-	gfs2_dinode_out(&ip->i_di, dibh->b_data);
+	di->di_height = cpu_to_be16(ip->i_di.di_height);
+	di->di_blocks = cpu_to_be64(ip->i_di.di_blocks);
 	brelse(dibh);
 	return error;
 }

fs/gfs2/inode.c

@@ -1166,6 +1166,7 @@ int gfs2_glock_nq_atime(struct gfs2_holder *gh)
 		curtime = get_seconds();
 		if (curtime - ip->i_di.di_atime >= quantum) {
 			struct buffer_head *dibh;
+			struct gfs2_dinode *di;
 
 			error = gfs2_trans_begin(sdp, RES_DINODE, 0);
 			if (error == -EROFS)
@@ -1180,7 +1181,8 @@ int gfs2_glock_nq_atime(struct gfs2_holder *gh)
 			ip->i_di.di_atime = curtime;
 
 			gfs2_trans_add_bh(ip->i_gl, dibh, 1);
-			gfs2_dinode_out(&ip->i_di, dibh->b_data);
+			di = (struct gfs2_dinode *)dibh->b_data;
+			di->di_atime = cpu_to_be64(ip->i_di.di_atime);
 			brelse(dibh);
 
 			gfs2_trans_end(sdp);

fs/gfs2/ops_address.c

@@ -460,7 +460,8 @@ static int gfs2_commit_write(struct file *file, struct page *page,
 	struct gfs2_sbd *sdp = GFS2_SB(inode);
 	int error = -EOPNOTSUPP;
 	struct buffer_head *dibh;
-	struct gfs2_alloc *al = &ip->i_alloc;;
+	struct gfs2_alloc *al = &ip->i_alloc;
+	struct gfs2_dinode *di;
 
 	if (gfs2_assert_withdraw(sdp, gfs2_glock_is_locked_by_me(ip->i_gl)))
                 goto fail_nounlock;
@@ -470,6 +471,7 @@ static int gfs2_commit_write(struct file *file, struct page *page,
 		goto fail_endtrans;
 
 	gfs2_trans_add_bh(ip->i_gl, dibh, 1);
+	di = (struct gfs2_dinode *)dibh->b_data;
 
 	if (gfs2_is_stuffed(ip)) {
 		u64 file_size;
@@ -495,10 +497,16 @@ static int gfs2_commit_write(struct file *file, struct page *page,
 			goto fail;
 	}
 
-	if (ip->i_di.di_size < inode->i_size)
+	if (ip->i_di.di_size < inode->i_size) {
 		ip->i_di.di_size = inode->i_size;
+		di->di_size = cpu_to_be64(inode->i_size);
+	}
+
+	di->di_mode = cpu_to_be32(inode->i_mode);
+	di->di_atime = cpu_to_be64(inode->i_atime.tv_sec);
+	di->di_mtime = cpu_to_be64(inode->i_mtime.tv_sec);
+	di->di_ctime = cpu_to_be64(inode->i_ctime.tv_sec);
 
-	gfs2_dinode_out(&ip->i_di, dibh->b_data);
 	brelse(dibh);
 	gfs2_trans_end(sdp);
 	if (al->al_requested) {