Re: [dm-devel] dm-thin f.req. : SEEK_DATA / SEEK_HOLE / SEEK_DISCARD

[Christoph Hellwig <hch infradead org>]

On Tue, May 01, 2012 at 02:53:22PM +0200, Spelic wrote:
> Dear dm-thin developers,
> I thought that it would be immensely useful to have a SEEK_DATA /
> SEEK_HOLE implementation for dm-thin and/or even for the older
> non-thin snapshotting mechanism.

You can't implement it direct as device mapper doesn't implement the
file operations.  But I think adding block device operations that back
it would be a good idea, they could also implemented for arrays
implementing thin provisioning using the GET LBA STATUS scsi command.