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);
        if (csum_size > sizeof(inline_result)) {
                result = kzalloc(csum_size, GFP_NOFS);
                if (!result)
-                       return 1;
+                       return -ENOMEM;
        } else {
                result = (char *)&inline_result;
        }
                                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);
        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,
                                       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