Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
From:   "NeilBrown" <neilb@suse.de>
To:     "Frank Filz" <ffilzlnx@mindspring.com>
Cc:     "'J. Bruce Fields'" <bfields@fieldses.org>,
        "'Chuck Lever'" <chuck.lever@oracle.com>,
        linux-nfs@vger.kernel.org, "'Josef Bacik'" <josef@toxicpanda.com>
Subject: RE: [PATCH v2] BTRFS/NFSD: provide more unique inode number for btrfs export
In-reply-to: <002901d79b53$41ddba40$c5992ec0$@mindspring.com>
References: <162995209561.7591.4202079352301963089@noble.neil.brown.name>,
 <162995778427.7591.11743795294299207756@noble.neil.brown.name>,
 <20210826201916.GB10730@fieldses.org>,
 <163001583884.7591.13328510041463261313@noble.neil.brown.name>,
 <002901d79b53$41ddba40$c5992ec0$@mindspring.com>
Date:   Sat, 28 Aug 2021 08:57:07 +1000
Message-id: <163010502766.7591.10398654528737145909@noble.neil.brown.name>
Precedence: bulk

On Sat, 28 Aug 2021, Frank Filz wrote:
>=20
> Changing the fsid for sub-volumes is Ganesha's solution (before adding
>  that, we couldn't even export the sub-volumes at all).=20

What does Ganesha use for the mounted-on-fileid? There doesn't seem to
be an "obvious" answer so I wonder what was chosen.

>=20
> Mangling the fileid is definitely the best solution if there will be lots o=
f sub-volumes. For a few sub-volumes changing fsid does create additional mou=
nt points on the client with some issues, but does guarantee there will be no=
 fileid collision.
>=20
> My gut feel is your solution is the best one and Ganesha may need to switch=
 to that solution.

Thanks for the encouragement.  Changing the fsid does seem easier is
many ways, but I don't really like the consequences or implications.

Thanks,
NeilBrown