[Ocfs2-devel] [LFS/MM TOPIC] fs reflink issues, fs online scrub/check, etc

[Ocfs2-devel] [LFS/MM TOPIC] fs reflink issues, fs online scrub/check, etc

[Darrick J. Wong]

[resend, email exploded, sorry...]

Hi,

I want to discuss a few FS related topics that I haven't already seen on
the mailing lists:

 * Shared pagecache pages for reflinked files (and by extension making dax
   work with reflink on xfs)

 * Providing a simple interface for scrubbing filesystem metadata in the
   background (the online check thing).  Ideally we'd make it easy to discover
   what kind of metadata there is to check and provide a simple interface to
   check the metadata, once discovered.  This is a tricky interface topic
   since FS design differs pretty widely.

 * Rudimentary online repair and rebuilding (xfs) from secondary metadata

 * Working out the variances in the btrfs/xfs/ocfs2/nfs reflink implementations
   and making sure they all get test coverage

I would also like participate in some of the proposed discussions:

 * The ext4 summit (and whatever meeting of XFS devs may happen)

 * Integrating existing filesystems into pmem, or hallway bofs about designing
   new filesystems for pmem

 * Actually seeing the fs developers (well, everyone!) in person again :)

--Darrick

[Ocfs2-devel] [LFS/MM TOPIC] fs reflink issues, fs online scrub/check, etc

[Steve French]

Since SMB3 protocol has at least three ways to do copy offload (server
side copy),
the reflink topic is of interest to me and likely useful to discuss
for Samba server as
well as client (cifs.ko)

On Wed, Feb 10, 2016 at 1:19 PM Darrick J. Wong <darrick.wong@oracle.com> wrote:
>
> [resend, email exploded, sorry...]
>
> Hi,
>
> I want to discuss a few FS related topics that I haven't already seen on
> the mailing lists:
>
>  * Shared pagecache pages for reflinked files (and by extension making dax
>    work with reflink on xfs)
>
>  * Providing a simple interface for scrubbing filesystem metadata in the
>    background (the online check thing).  Ideally we'd make it easy to discover
>    what kind of metadata there is to check and provide a simple interface to
>    check the metadata, once discovered.  This is a tricky interface topic
>    since FS design differs pretty widely.
>
>  * Rudimentary online repair and rebuilding (xfs) from secondary metadata
>
>  * Working out the variances in the btrfs/xfs/ocfs2/nfs reflink implementations
>    and making sure they all get test coverage
>
> I would also like participate in some of the proposed discussions:
>
>  * The ext4 summit (and whatever meeting of XFS devs may happen)
>
>  * Integrating existing filesystems into pmem, or hallway bofs about designing
>    new filesystems for pmem
>
>  * Actually seeing the fs developers (well, everyone!) in person again :)
>
> --Darrick
> --
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-- 
Thanks,

Steve

[Ocfs2-devel] [Lsf-pc] [LFS/MM TOPIC] fs reflink issues, fs online scrub/check, etc

[Darrick J. Wong]

On Tue, Jan 21, 2020 at 09:35:22AM +0200, Amir Goldstein wrote:
> On Tue, Jan 21, 2020 at 3:19 AM Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
> >
> > Didn't see the original mail, so reply here.
> 
> Heh! Original email was from 2016, but most of Darrick's wish list is
> still relevant in 2020 :)

Grumble grumble stable behavior of clonerange/deduperange ioctls across
filesystems grumble grumble.

> I for one would be very interested in getting an update on the
> progress of pagecache
> page sharing if there is anyone working on it.

Me too.  I guess it's the 21st, I should really send in a proposal for
*this year's* LSFMMBPFLOLBBQ.

--D

> Thanks,
> Amir.

[Ocfs2-devel] [Lsf-pc] [LFS/MM TOPIC] fs reflink issues, fs online scrub/check, etc

[Dave Chinner]

On Tue, Jan 21, 2020 at 04:47:27PM -0800, Dan Williams wrote:
> On Tue, Jan 21, 2020 at 2:02 PM Matthew Wilcox <willy@infradead.org> wrote:
> >
> > On Tue, Jan 21, 2020 at 08:18:40AM -0800, Darrick J. Wong wrote:
> > > On Tue, Jan 21, 2020 at 09:35:22AM +0200, Amir Goldstein wrote:
> > > > On Tue, Jan 21, 2020 at 3:19 AM Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
> > > > >
> > > > > Didn't see the original mail, so reply here.
> > > >
> > > > Heh! Original email was from 2016, but most of Darrick's wish list is
> > > > still relevant in 2020 :)
> > >
> > > Grumble grumble stable behavior of clonerange/deduperange ioctls across
> > > filesystems grumble grumble.
> > >
> > > > I for one would be very interested in getting an update on the
> > > > progress of pagecache
> > > > page sharing if there is anyone working on it.
> > >
> > > Me too.  I guess it's the 21st, I should really send in a proposal for
> > > *this year's* LSFMMBPFLOLBBQ.
> >
> > I still have Strong Opinions on how pagecache page sharing should be done
> > ... and half a dozen more important projects ahead of it in my queue.
> > So I have no update on this.
> 
> We should plan to huddle on this especially if I don't get an RFC for
> dax-reflink support out before the summit.

It would be a good idea to share your ideas about how you plan to
solve this problem earlier rather than later so you don't waste time
going down a path that is incompatible with what the filesystems
need to/want to/can do.

Cheers,

Dave.
-- 
Dave Chinner
david at fromorbit.com