Re: [PATCH v2 2/2] Btrfs: snapshot-aware defrag

[Liu Bo <bo.li.liu@oracle.com>]

On Thu, Sep 06, 2012 at 09:11:53AM -0400, Josef Bacik wrote:
> On Wed, Sep 05, 2012 at 07:10:52PM -0600, Liu Bo wrote:
> > This comes from one of btrfs's project ideas,
> > As we defragment files, we break any sharing from other snapshots.
> > The balancing code will preserve the sharing, and defrag needs to grow this
> > as well.
> > 
> > Now we're able to fill the blank with this patch, in which we make full use of
> > backref walking stuff.
> > 
> > Here is the basic idea,
> > o  set the writeback ranges started by defragment with flag EXTENT_DEFRAG
> > o  at endio, after we finish updating fs tree, we use backref walking to find
> >    all parents of the ranges and re-link them with the new COWed file layout by
> >    adding corresponding backrefs.
> > 
> > Original-Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
> > Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
> > ---
> > v2: rebase against the latest btrfs-repo
> > 
> 
> Heh well it doesn't apply onto btrfs-next, try again please :).  Thanks,
> 
> Josef

oh, sorry for the trouble, I'll redo a btrfs-next version :)

thanks,
liubo