On Fri, Sep 23, 2016 at 01:44:44PM -0700, Liu Bo wrote: > @@ -3732,15 +3734,21 @@ static noinline_for_stack int write_one_eb(struct > extent_buffer *eb, > if (btrfs_header_owner(eb) == BTRFS_TREE_LOG_OBJECTID) > bio_flags = EXTENT_BIO_TREE_LOG; > > - /* set btree node beyond nritems with 0 to avoid stale content */ > + /* set btree blocks beyond nritems with 0 to avoid stale content. */ > + nritems = btrfs_header_nritems(eb); > if (btrfs_header_level(eb) > 0) { > - u32 nritems; > - unsigned long end; > - > - nritems = btrfs_header_nritems(eb); > end = btrfs_node_key_ptr_offset(nritems); > > memset_extent_buffer(eb, 0, end, eb->len - end); > + } else { > + /* > + * leaf: > + * header 0 1 2 .. N ... data_N .. data_2 data_1 data_0 > + */ > + start = btrfs_item_nr_offset(nritems);
So, AFAICS this also works for empty root nodes (nritems == 0). It's hidden in leaf_data_end that actually looks at nritems and decides. Reviewed-by: David Sterba <dste...@suse.com> > + end = btrfs_leaf_data(eb) + > + leaf_data_end(fs_info->tree_root, eb); > + memset_extent_buffer(eb, 0, start, end - start); -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html