[dm-devel] Re: [PATCH v2] dm snapshot: revise snapshot_resume's exception handover

[Mike Snitzer]

On Wed, Nov 04 2009 at  5:20pm -0500,
Mike Snitzer <snitzer at redhat.com> wrote:

> On Wed, Nov 04 2009 at  5:11pm -0500,
> Mike Snitzer <snitzer at redhat.com> wrote:
> 
> > Until now snapshot_resume only allowed the resuming snapshot to get the
> > exception store from another snapshot.
> > 
> > Revise snapshot_resume's exception handover to allow a snapshot to
> > handover its exceptions to another snapshot prior to resuming.
> > 
> > This is needed to accomodate the following sequence:
> > new_snapshot->ctr
> > old_snapshot->suspend
> > old_snapshot->resume
> > new_snapshot->resume
> > 
> > lvm2 relies on this sequence if 'lvchange --refresh' is used to start a
> > snapshot merge that was deferred until both origin and snapshot were not
> > in use.
> 
> FYI, the above is the last of 3 patches in the "exception handover"
> series, the patch order is:

Ok, actually this 'suspended' flag patch is the first; so its 4 patches:

dm snapshot: add suspended flag to dm_snapshot
http://patchwork.kernel.org/patch/55021/
 
> dm snapshot: initial support for exception handover
> http://patchwork.kernel.org/patch/55022/
> 
> dm snapshot: exception handover improvements
> http://patchwork.kernel.org/patch/55569/
> 
> dm snapshot: revise snapshot_resume's exception handover
> http://patchwork.kernel.org/patch/57787/