Re: [PATCH v10 00/12] ceph: support idmapped mounts

[Xiubo Li]

On 8/8/23 14:30, Aleksandr Mikhalitsyn wrote:
> On Tue, Aug 8, 2023 at 2:45 AM Xiubo Li <xiubli@xxxxxxxxxx> wrote:
> > LGTM.
> >
> > Reviewed-by: Xiubo Li <xiubli@xxxxxxxxxx>
> >
> > 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.

I will check it.

Thanks

- Xiubo


> 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 continue
> > > 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 request")
> > > commit. Now we take idmap refcounter just in place where req->r_mnt_idmap
> > > is filled. It's more safer approach and prevents possible refcounter underflow
> > > on error paths where __register_request wasn't called but ceph_mdsc_release_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_inline)
> > >
> > > Changelog for version 7:
> > > - rebased on top of testing branch
> > > - this thing now requires a new cephfs protocol extension CEPHFS_FEATURE_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 userspace 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@xxxxxxxxxx/
> > > v2: https://lore.kernel.org/lkml/20230524153316.476973-1-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/
> > > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v2
> > > v3: https://lore.kernel.org/lkml/20230607152038.469739-1-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/#t
> > > v4: https://lore.kernel.org/lkml/20230607180958.645115-1-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/#t
> > > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v4
> > > v5: https://lore.kernel.org/lkml/20230608154256.562906-1-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/#t
> > > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v5
> > > v6: https://lore.kernel.org/lkml/20230609093125.252186-1-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/
> > > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v6
> > > v7: https://lore.kernel.org/all/20230726141026.307690-1-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/
> > > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v7
> > > v8: https://lore.kernel.org/all/20230803135955.230449-1-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/
> > > tree: -
> > > v9: https://lore.kernel.org/all/20230804084858.126104-1-aleksandr.mikhalitsyn@xxxxxxxxxxxxx/
> > > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v9
> > >
> > > Kind regards,
> > > Alex
> > >
> > > Original description from Christian:
> > > ========================================================================
> > > 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 containers.
> > > 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=ceph
> > > export TEST_DIR=/mnt/test
> > > export TEST_DEV=10.103.182.10:6789:/
> > > export TEST_FS_MOUNT_OPTS="-o name=admin,secret=$password
> > >
> > > and then simply call
> > >
> > > sudo ./check -g idmapped
> > >
> > > ========================================================================
> > >
> > > 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(-)