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From:   Aleksandr Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Date:   Tue, 8 Aug 2023 08:30:55 +0200
Message-ID: <CAEivzxfsj82q2x3C2U6yemB9qRrLnW+fLAAE=e7Tq-LDDfH0-g@mail.gmail.com>
Subject: Re: [PATCH v10 00/12] ceph: support idmapped mounts
To:     Xiubo Li <xiubli@redhat.com>
Cc:     brauner@kernel.org, stgraber@ubuntu.com,
        linux-fsdevel@vger.kernel.org, Ilya Dryomov <idryomov@gmail.com>,
        Jeff Layton <jlayton@kernel.org>, ceph-devel@vger.kernel.org,
        linux-kernel@vger.kernel.org
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On Tue, Aug 8, 2023 at 2:45=E2=80=AFAM Xiubo Li <xiubli@redhat.com> wrote:
>
> LGTM.
>
> Reviewed-by: Xiubo Li <xiubli@redhat.com>
>
> I will queue this to the 'testing' branch and then we will run ceph qa
> tests.

Thanks, Xiubo!

JFYI: commit ordering in
https://github.com/ceph/ceph-client/commits/testing looks a little bit
weird
probably something got wrong during patch application to the tree.

Kind regards,
Alex

>
> Thanks Alex.
>
> - Xiubo
>
> On 8/7/23 21:26, Alexander Mikhalitsyn wrote:
> > Dear friends,
> >
> > This patchset was originally developed by Christian Brauner but I'll co=
ntinue
> > to push it forward. Christian allowed me to do that :)
> >
> > This feature is already actively used/tested with LXD/LXC project.
> >
> > Git tree (based on https://github.com/ceph/ceph-client.git testing):
> > v10: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v10
> > current: https://github.com/mihalicyn/linux/tree/fs.idmapped.ceph
> >
> > In the version 3 I've changed only two commits:
> > - fs: export mnt_idmap_get/mnt_idmap_put
> > - ceph: allow idmapped setattr inode op
> > and added a new one:
> > - ceph: pass idmap to __ceph_setattr
> >
> > In the version 4 I've reworked the ("ceph: stash idmapping in mdsc requ=
est")
> > commit. Now we take idmap refcounter just in place where req->r_mnt_idm=
ap
> > is filled. It's more safer approach and prevents possible refcounter un=
derflow
> > on error paths where __register_request wasn't called but ceph_mdsc_rel=
ease_request is
> > called.
> >
> > Changelog for version 5:
> > - a few commits were squashed into one (as suggested by Xiubo Li)
> > - started passing an idmapping everywhere (if possible), so a caller
> > UID/GID-s will be mapped almost everywhere (as suggested by Xiubo Li)
> >
> > Changelog for version 6:
> > - rebased on top of testing branch
> > - passed an idmapping in a few places (readdir, ceph_netfs_issue_op_inl=
ine)
> >
> > Changelog for version 7:
> > - rebased on top of testing branch
> > - this thing now requires a new cephfs protocol extension CEPHFS_FEATUR=
E_HAS_OWNER_UIDGID
> > https://github.com/ceph/ceph/pull/52575
> >
> > Changelog for version 8:
> > - rebased on top of testing branch
> > - added enable_unsafe_idmap module parameter to make idmapped mounts
> > work with old MDS server versions
> > - properly handled case when old MDS used with new kernel client
> >
> > Changelog for version 9:
> > - added "struct_len" field in struct ceph_mds_request_head as requested=
 by Xiubo Li
> >
> > Changelog for version 10:
> > - fill struct_len field properly (use cpu_to_le32)
> > - add extra checks IS_CEPH_MDS_OP_NEWINODE(..) as requested by Xiubo to=
 match
> >    userspace client behavior
> > - do not set req->r_mnt_idmap for MKSNAP operation
> > - atomic_open: set req->r_mnt_idmap only for CEPH_MDS_OP_CREATE as user=
space client does
> >
> > I can confirm that this version passes xfstests and
> > tested with old MDS (without CEPHFS_FEATURE_HAS_OWNER_UIDGID)
> > and with recent MDS version.
> >
> > Links to previous versions:
> > v1: https://lore.kernel.org/all/20220104140414.155198-1-brauner@kernel.=
org/
> > v2: https://lore.kernel.org/lkml/20230524153316.476973-1-aleksandr.mikh=
alitsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v2
> > v3: https://lore.kernel.org/lkml/20230607152038.469739-1-aleksandr.mikh=
alitsyn@canonical.com/#t
> > v4: https://lore.kernel.org/lkml/20230607180958.645115-1-aleksandr.mikh=
alitsyn@canonical.com/#t
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v4
> > v5: https://lore.kernel.org/lkml/20230608154256.562906-1-aleksandr.mikh=
alitsyn@canonical.com/#t
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v5
> > v6: https://lore.kernel.org/lkml/20230609093125.252186-1-aleksandr.mikh=
alitsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v6
> > v7: https://lore.kernel.org/all/20230726141026.307690-1-aleksandr.mikha=
litsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v7
> > v8: https://lore.kernel.org/all/20230803135955.230449-1-aleksandr.mikha=
litsyn@canonical.com/
> > tree: -
> > v9: https://lore.kernel.org/all/20230804084858.126104-1-aleksandr.mikha=
litsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v9
> >
> > Kind regards,
> > Alex
> >
> > Original description from Christian:
> > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> > This patch series enables cephfs to support idmapped mounts, i.e. the
> > ability to alter ownership information on a per-mount basis.
> >
> > Container managers such as LXD support sharaing data via cephfs between
> > the host and unprivileged containers and between unprivileged container=
s.
> > They may all use different idmappings. Idmapped mounts can be used to
> > create mounts with the idmapping used for the container (or a different
> > one specific to the use-case).
> >
> > There are in fact more use-cases such as remapping ownership for
> > mountpoints on the host itself to grant or restrict access to different
> > users or to make it possible to enforce that programs running as root
> > will write with a non-zero {g,u}id to disk.
> >
> > The patch series is simple overall and few changes are needed to cephfs=
.
> > There is one cephfs specific issue that I would like to discuss and
> > solve which I explain in detail in:
> >
> > [PATCH 02/12] ceph: handle idmapped mounts in create_request_message()
> >
> > It has to do with how to handle mds serves which have id-based access
> > restrictions configured. I would ask you to please take a look at the
> > explanation in the aforementioned patch.
> >
> > The patch series passes the vfs and idmapped mount testsuite as part of
> > xfstests. To run it you will need a config like:
> >
> > [ceph]
> > export FSTYP=3Dceph
> > export TEST_DIR=3D/mnt/test
> > export TEST_DEV=3D10.103.182.10:6789:/
> > export TEST_FS_MOUNT_OPTS=3D"-o name=3Dadmin,secret=3D$password
> >
> > and then simply call
> >
> > sudo ./check -g idmapped
> >
> > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
> >
> > Alexander Mikhalitsyn (3):
> >    fs: export mnt_idmap_get/mnt_idmap_put
> >    ceph: add enable_unsafe_idmap module parameter
> >    ceph: pass idmap to __ceph_setattr
> >
> > Christian Brauner (9):
> >    ceph: stash idmapping in mdsc request
> >    ceph: handle idmapped mounts in create_request_message()
> >    ceph: pass an idmapping to mknod/symlink/mkdir
> >    ceph: allow idmapped getattr inode op
> >    ceph: allow idmapped permission inode op
> >    ceph: allow idmapped setattr inode op
> >    ceph/acl: allow idmapped set_acl inode op
> >    ceph/file: allow idmapped atomic_open inode op
> >    ceph: allow idmapped mounts
> >
> >   fs/ceph/acl.c                 |  6 +--
> >   fs/ceph/crypto.c              |  2 +-
> >   fs/ceph/dir.c                 |  4 ++
> >   fs/ceph/file.c                | 11 ++++-
> >   fs/ceph/inode.c               | 29 +++++++------
> >   fs/ceph/mds_client.c          | 78 ++++++++++++++++++++++++++++++++--=
-
> >   fs/ceph/mds_client.h          |  8 +++-
> >   fs/ceph/super.c               |  7 +++-
> >   fs/ceph/super.h               |  3 +-
> >   fs/mnt_idmapping.c            |  2 +
> >   include/linux/ceph/ceph_fs.h  | 10 ++++-
> >   include/linux/mnt_idmapping.h |  3 ++
> >   12 files changed, 136 insertions(+), 27 deletions(-)
> >
>