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From:   Ilya Dryomov <idryomov@gmail.com>
Date:   Mon, 11 Nov 2019 21:51:47 +0100
Message-ID: <CAOi1vP-kFnu_mJaTERHbSjBxQRvfXhFWF=9_nCaaFbh7ACiVhg@mail.gmail.com>
Subject: Re: [RFC PATCH 0/2] ceph: safely use 'copy-from' Op on Octopus OSDs
To:     Luis Henriques <lhenriques@suse.com>
Cc:     Sage Weil <sage@newdream.net>, Jeff Layton <jlayton@kernel.org>,
        "Yan, Zheng" <ukernel@gmail.com>,
        Ceph Development <ceph-devel@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Mon, Nov 11, 2019 at 5:30 PM Luis Henriques <lhenriques@suse.com> wrote:
>
> On Fri, Nov 08, 2019 at 05:31:01PM +0000, Luis Henriques wrote:
> <snip>
> > > - You'll need to add it for both OSDMap::Incremental and OSDMap
> > > - You'll need to make the encoding condition by updating the block like
> > > the one below from OSDMap::encode()
> > >
> > >     uint8_t v = 9;
> > >     if (!HAVE_FEATURE(features, SERVER_LUMINOUS)) {
> > >       v = 3;
> > >     } else if (!HAVE_FEATURE(features, SERVER_MIMIC)) {
> > >       v = 6;
> > >     } else if (!HAVE_FEATURE(features, SERVER_NAUTILUS)) {
> > >       v = 7;
> > >     }
> > >
> > > to include a SERVER_OCTOPUS case too.  Same goes for Incremental::encode()
> >
> > Awesome, thanks!  I'll give it a try, and test it with the appropriate
> > kernel client side changes to use this.
>
> Ok, I've got the patch bellow for the OSD code, which IIRC should do
> exactly what we want: duplicate the require_osd_release in the client
> side.
>
> Now, in order to quickly test this I've started adding flags to the
> CEPH_FEATURES_SUPPORTED_DEFAULT definition.  SERVER_MIMIC *seemed* to be
> Ok, but once I've added SERVER_NAUTILUS I've realized that we'll need to
> handle TYPE_MSGR2 address.  Which is a _big_ thing.  Is anyone already
> looking into adding support for msgr v2 to the kernel client?

It should be easy enough to hack around it for testing purposes.

I made some initial steps and hope to be able to dedicate the 5.6 cycle
to it.

Thanks,

                Ilya