u64 data_offset;
        u64 data_len;
        u64 file_offset;
+       /* Pointer to a file extent item of type regular or prealloc. */
        char *extent_buf;
-       u32 item_size;
        /*
         * Set to true when attempting to replace a file range with a new extent
         * described by this structure, set to false when attempting to clone an
 
        key.type = BTRFS_EXTENT_DATA_KEY;
        key.offset = clone_info->file_offset;
        ret = btrfs_insert_empty_item(trans, root, path, &key,
-                                     clone_info->item_size);
+                                     sizeof(struct btrfs_file_extent_item));
        if (ret)
                return ret;
        leaf = path->nodes[0];
        slot = path->slots[0];
        write_extent_buffer(leaf, clone_info->extent_buf,
                            btrfs_item_ptr_offset(leaf, slot),
-                           clone_info->item_size);
+                           sizeof(struct btrfs_file_extent_item));
        extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
+       ASSERT(btrfs_file_extent_type(leaf, extent) != BTRFS_FILE_EXTENT_INLINE);
        btrfs_set_file_extent_offset(leaf, extent, clone_info->data_offset);
        btrfs_set_file_extent_num_bytes(leaf, extent, clone_len);
        if (clone_info->is_new_extent)
 
        extent_info.data_len = len;
        extent_info.file_offset = file_offset;
        extent_info.extent_buf = (char *)&stack_fi;
-       extent_info.item_size = sizeof(stack_fi);
        extent_info.is_new_extent = true;
        extent_info.qgroup_reserved = ret;
        extent_info.insertions = 0;
 
                        clone_info.data_len = datal;
                        clone_info.file_offset = new_key.offset;
                        clone_info.extent_buf = buf;
-                       clone_info.item_size = size;
                        clone_info.is_new_extent = false;
                        ret = btrfs_punch_hole_range(inode, path, drop_start,
                                        new_key.offset + datal - 1, &clone_info,