ocfs2: return ENOMEM when sb_getblk() fails

The only reason for sb_getblk() failing is if it can't allocate the
buffer_head.  So return ENOMEM instead when it fails.

[joseph.qi@huawei.com: ocfs2_symlink_get_block() and ocfs2_read_blocks_sync() and ocfs2_read_blocks() need the same change]
Signed-off-by: Rui Xiang <rui.xiang@huawei.com>
Reviewed-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/dir.c

@@ -2349,7 +2349,7 @@ static int ocfs2_dx_dir_attach_index(struct ocfs2_super *osb,
 
 	dx_root_bh = sb_getblk(osb->sb, dr_blkno);
 	if (dx_root_bh == NULL) {
-		ret = -EIO;
+		ret = -ENOMEM;
 		goto out;
 	}
 	ocfs2_set_new_buffer_uptodate(INODE_CACHE(dir), dx_root_bh);
@@ -2422,7 +2422,7 @@ static int ocfs2_dx_dir_format_cluster(struct ocfs2_super *osb,
 	for (i = 0; i < num_dx_leaves; i++) {
 		bh = sb_getblk(osb->sb, start_blk + i);
 		if (bh == NULL) {
-			ret = -EIO;
+			ret = -ENOMEM;
 			goto out;
 		}
 		dx_leaves[i] = bh;
@@ -2929,7 +2929,7 @@ static int ocfs2_expand_inline_dir(struct inode *dir, struct buffer_head *di_bh,
 	blkno = ocfs2_clusters_to_blocks(dir->i_sb, bit_off);
 	dirdata_bh = sb_getblk(sb, blkno);
 	if (!dirdata_bh) {
-		ret = -EIO;
+		ret = -ENOMEM;
 		mlog_errno(ret);
 		goto out_commit;
 	}
@@ -3159,7 +3159,7 @@ static int ocfs2_do_extend_dir(struct super_block *sb,
 
 	*new_bh = sb_getblk(sb, p_blkno);
 	if (!*new_bh) {
-		status = -EIO;
+		status = -ENOMEM;
 		mlog_errno(status);
 		goto bail;
 	}