On Thu, Mar 08, 2012 at 06:15:17PM +0100, Paolo Bonzini wrote: > SEEK_DATA and SEEK_HOLE can be used to implement the is_allocated > callback for raw files. These currently work on btrfs, with an XFS > implementation also coming soon.
Btw - if you're interested in a bit more kernel hacking it would be cool to implement it for block devices using GET LBA STATUS.
