btrfs: csum_tree_block: return proper errno value

Signed-off-by: Alex Lyakas <alex@zadarastorage.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -302,7 +302,7 @@ static int csum_tree_block(struct btrfs_fs_info *fs_info,
 		err = map_private_extent_buffer(buf, offset, 32,
 					&kaddr, &map_start, &map_len);
 		if (err)
-			return 1;
+			return err;
 		cur_len = min(len, map_len - (offset - map_start));
 		crc = btrfs_csum_data(kaddr + offset - map_start,
 				      crc, cur_len);
@@ -312,7 +312,7 @@ static int csum_tree_block(struct btrfs_fs_info *fs_info,
 	if (csum_size > sizeof(inline_result)) {
 		result = kzalloc(csum_size, GFP_NOFS);
 		if (!result)
-			return 1;
+			return -ENOMEM;
 	} else {
 		result = (char *)&inline_result;
 	}
@@ -333,7 +333,7 @@ static int csum_tree_block(struct btrfs_fs_info *fs_info,
 				val, found, btrfs_header_level(buf));
 			if (result != (char *)&inline_result)
 				kfree(result);
-			return 1;
+			return -EUCLEAN;
 		}
 	} else {
 		write_extent_buffer(buf, result, 0, csum_size);
@@ -515,8 +515,7 @@ static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page)
 	found_start = btrfs_header_bytenr(eb);
 	if (WARN_ON(found_start != start || !PageUptodate(page)))
 		return 0;
-	csum_tree_block(fs_info, eb, 0);
-	return 0;
+	return csum_tree_block(fs_info, eb, 0);
 }
 
 static int check_tree_block_fsid(struct btrfs_fs_info *fs_info,
@@ -660,10 +659,8 @@ static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
 				       eb, found_level);
 
 	ret = csum_tree_block(fs_info, eb, 1);
-	if (ret) {
-		ret = -EIO;
+	if (ret)
 		goto err;
-	}
 
 	/*
 	 * If this is a leaf block and it is corrupt, set the corrupt bit so