On Tue, Aug 23, 2016 at 03:22:58PM -0700, Liu Bo wrote:

Right now we treat leaf which has zero item as a valid one
because we could have an empty tree, that is, a root that is
also a leaf without any item, however, in the same case but
when the leaf is not a root, we can end up with hitting the
BUG_ON(1) in btrfs_extend_item() called by
setup_inline_extent_backref().

This makes us check the situation as a corruption if leaf is
not its own root.

Signed-off-by: Liu Bo <redacted>

Reviewed-by: David Sterba <dsterba@suse.com>