On Mon, Nov 14, 2016 at 11:47:15PM -0800, Darrick J. Wong wrote: > XFS doesn't split the extent either, internally. The FIEMAP > implementation cross-references extent data with the refcount records, > using extra struct fiemap_extent to report precisely which blocks are > shared and which aren't. ocfs2 exhibits the same behavior. And I think exact reporting of already shared extents in FIEMAP is extremely important - independent of the internal implementation btrfs should report the extents correctly. -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html