[dm-devel] Re: dm snapshot: implement .iterate_devices

Mike Snitzer snitzer at redhat.com
Mon Aug 24 22:55:15 UTC 2009


On Mon, Aug 24 2009 at  5:15pm -0400,
Andrew Morton <akpm at linux-foundation.org> wrote:

> On Sun, 23 Aug 2009 02:11:07 -0400
> Mike Snitzer <snitzer at redhat.com> wrote:
> 
> > This patch implements .iterate_devices for the origin and snapshot
> > targets.  dm-snapshot's lack of .iterate_devices resulted in the
> > inability to properly establish queue_limits for both targets.  
> > 
> > With 4K sector drives: an unfortunate side-effect of not establishing
> > proper limits in either targets' DM device was that IO to the devices
> > would fail even though both had been created without error.
> 
> Does this make the patch a regression fix?

Yes.
 
> > Commit af4874e03ed82f050d5872d8c39ce64bf16b5c38 should have implemented
> > .iterate_devices for dm-snap.c's origin and snapshot targets.
> 
> Please use the form af4874e03ed82f050d5872d8c39ce64bf16b5c38 ("dm
> target:s introduce iterate devices fn") when referring to commits. 
> Because commits might have different IDs in different trees (I think
> that's the reason).

OK, thanks for picking this up.  I believe Alasdair is back from
vacation tomorrow and will be pushing other remaining DM fixes for
2.6.31 final.




More information about the dm-devel mailing list