[v10,00/12] ceph: support idmapped mounts

  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@kernel.org/
v2: https://lore.kernel.org/lkml/20230524153316.476973-1-aleksandr.mikhalitsyn@canonical.com/
tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v2
v3: https://lore.kernel.org/lkml/20230607152038.469739-1-aleksandr.mikhalitsyn@canonical.com/#t
v4: https://lore.kernel.org/lkml/20230607180958.645115-1-aleksandr.mikhalitsyn@canonical.com/#t
tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v4
v5: https://lore.kernel.org/lkml/20230608154256.562906-1-aleksandr.mikhalitsyn@canonical.com/#t
tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v5
v6: https://lore.kernel.org/lkml/20230609093125.252186-1-aleksandr.mikhalitsyn@canonical.com/
tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v6
v7: https://lore.kernel.org/all/20230726141026.307690-1-aleksandr.mikhalitsyn@canonical.com/
tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v7
v8: https://lore.kernel.org/all/20230803135955.230449-1-aleksandr.mikhalitsyn@canonical.com/
tree: -
v9: https://lore.kernel.org/all/20230804084858.126104-1-aleksandr.mikhalitsyn@canonical.com/
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(-)
  

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 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@kernel.org/
> v2: https://lore.kernel.org/lkml/20230524153316.476973-1-aleksandr.mikhalitsyn@canonical.com/
> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v2
> v3: https://lore.kernel.org/lkml/20230607152038.469739-1-aleksandr.mikhalitsyn@canonical.com/#t
> v4: https://lore.kernel.org/lkml/20230607180958.645115-1-aleksandr.mikhalitsyn@canonical.com/#t
> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v4
> v5: https://lore.kernel.org/lkml/20230608154256.562906-1-aleksandr.mikhalitsyn@canonical.com/#t
> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v5
> v6: https://lore.kernel.org/lkml/20230609093125.252186-1-aleksandr.mikhalitsyn@canonical.com/
> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v6
> v7: https://lore.kernel.org/all/20230726141026.307690-1-aleksandr.mikhalitsyn@canonical.com/
> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v7
> v8: https://lore.kernel.org/all/20230803135955.230449-1-aleksandr.mikhalitsyn@canonical.com/
> tree: -
> v9: https://lore.kernel.org/all/20230804084858.126104-1-aleksandr.mikhalitsyn@canonical.com/
> 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(-)
>
  

On Tue, Aug 8, 2023 at 2:45 AM 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 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@kernel.org/
> > v2: https://lore.kernel.org/lkml/20230524153316.476973-1-aleksandr.mikhalitsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v2
> > v3: https://lore.kernel.org/lkml/20230607152038.469739-1-aleksandr.mikhalitsyn@canonical.com/#t
> > v4: https://lore.kernel.org/lkml/20230607180958.645115-1-aleksandr.mikhalitsyn@canonical.com/#t
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v4
> > v5: https://lore.kernel.org/lkml/20230608154256.562906-1-aleksandr.mikhalitsyn@canonical.com/#t
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v5
> > v6: https://lore.kernel.org/lkml/20230609093125.252186-1-aleksandr.mikhalitsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v6
> > v7: https://lore.kernel.org/all/20230726141026.307690-1-aleksandr.mikhalitsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v7
> > v8: https://lore.kernel.org/all/20230803135955.230449-1-aleksandr.mikhalitsyn@canonical.com/
> > tree: -
> > v9: https://lore.kernel.org/all/20230804084858.126104-1-aleksandr.mikhalitsyn@canonical.com/
> > 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(-)
> >
>
  

On 8/8/23 14:30, Aleksandr Mikhalitsyn wrote:
> On Tue, Aug 8, 2023 at 2:45 AM 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.

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@kernel.org/
>>> v2: https://lore.kernel.org/lkml/20230524153316.476973-1-aleksandr.mikhalitsyn@canonical.com/
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v2
>>> v3: https://lore.kernel.org/lkml/20230607152038.469739-1-aleksandr.mikhalitsyn@canonical.com/#t
>>> v4: https://lore.kernel.org/lkml/20230607180958.645115-1-aleksandr.mikhalitsyn@canonical.com/#t
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v4
>>> v5: https://lore.kernel.org/lkml/20230608154256.562906-1-aleksandr.mikhalitsyn@canonical.com/#t
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v5
>>> v6: https://lore.kernel.org/lkml/20230609093125.252186-1-aleksandr.mikhalitsyn@canonical.com/
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v6
>>> v7: https://lore.kernel.org/all/20230726141026.307690-1-aleksandr.mikhalitsyn@canonical.com/
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v7
>>> v8: https://lore.kernel.org/all/20230803135955.230449-1-aleksandr.mikhalitsyn@canonical.com/
>>> tree: -
>>> v9: https://lore.kernel.org/all/20230804084858.126104-1-aleksandr.mikhalitsyn@canonical.com/
>>> 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(-)
>>>
  

On Tue, Aug 8, 2023 at 2:45 AM 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 Alex.
>
> - Xiubo

Hi Xiubo,

will this series be landed to 6.6?

Userspace part was backported and merged to the Ceph Quincy release
(https://github.com/ceph/ceph/pull/53139)
And waiting to be tested and merged to the Ceph reef and pacific releases.
But the kernel part is still in the testing branch.

Kind regards,
Alex

>
> 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@kernel.org/
> > v2: https://lore.kernel.org/lkml/20230524153316.476973-1-aleksandr.mikhalitsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v2
> > v3: https://lore.kernel.org/lkml/20230607152038.469739-1-aleksandr.mikhalitsyn@canonical.com/#t
> > v4: https://lore.kernel.org/lkml/20230607180958.645115-1-aleksandr.mikhalitsyn@canonical.com/#t
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v4
> > v5: https://lore.kernel.org/lkml/20230608154256.562906-1-aleksandr.mikhalitsyn@canonical.com/#t
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v5
> > v6: https://lore.kernel.org/lkml/20230609093125.252186-1-aleksandr.mikhalitsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v6
> > v7: https://lore.kernel.org/all/20230726141026.307690-1-aleksandr.mikhalitsyn@canonical.com/
> > tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v7
> > v8: https://lore.kernel.org/all/20230803135955.230449-1-aleksandr.mikhalitsyn@canonical.com/
> > tree: -
> > v9: https://lore.kernel.org/all/20230804084858.126104-1-aleksandr.mikhalitsyn@canonical.com/
> > 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(-)
> >
>
  

On 10/17/23 17:20, Aleksandr Mikhalitsyn wrote:
> On Tue, Aug 8, 2023 at 2:45 AM 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 Alex.
>>
>> - Xiubo
> Hi Xiubo,
>
> will this series be landed to 6.6?
>
> Userspace part was backported and merged to the Ceph Quincy release
> (https://github.com/ceph/ceph/pull/53139)
> And waiting to be tested and merged to the Ceph reef and pacific releases.
> But the kernel part is still in the testing branch.

This changes have been in the 'testing' branch for more than two mounts 
and well test, till now we haven't seen any issue.

IMO it should be ready.

Ilya ?

Thanks

- Xiubo


> Kind regards,
> Alex
>
>> 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@kernel.org/
>>> v2: https://lore.kernel.org/lkml/20230524153316.476973-1-aleksandr.mikhalitsyn@canonical.com/
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v2
>>> v3: https://lore.kernel.org/lkml/20230607152038.469739-1-aleksandr.mikhalitsyn@canonical.com/#t
>>> v4: https://lore.kernel.org/lkml/20230607180958.645115-1-aleksandr.mikhalitsyn@canonical.com/#t
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v4
>>> v5: https://lore.kernel.org/lkml/20230608154256.562906-1-aleksandr.mikhalitsyn@canonical.com/#t
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v5
>>> v6: https://lore.kernel.org/lkml/20230609093125.252186-1-aleksandr.mikhalitsyn@canonical.com/
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v6
>>> v7: https://lore.kernel.org/all/20230726141026.307690-1-aleksandr.mikhalitsyn@canonical.com/
>>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v7
>>> v8: https://lore.kernel.org/all/20230803135955.230449-1-aleksandr.mikhalitsyn@canonical.com/
>>> tree: -
>>> v9: https://lore.kernel.org/all/20230804084858.126104-1-aleksandr.mikhalitsyn@canonical.com/
>>> 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(-)
>>>
  

On Thu, Oct 19, 2023 at 7:42 AM Xiubo Li <xiubli@redhat.com> wrote:
>
>
> On 10/17/23 17:20, Aleksandr Mikhalitsyn wrote:
> > On Tue, Aug 8, 2023 at 2:45 AM 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 Alex.
> >>
> >> - Xiubo
> > Hi Xiubo,
> >
> > will this series be landed to 6.6?
> >
> > Userspace part was backported and merged to the Ceph Quincy release
> > (https://github.com/ceph/ceph/pull/53139)
> > And waiting to be tested and merged to the Ceph reef and pacific releases.
> > But the kernel part is still in the testing branch.
>
> This changes have been in the 'testing' branch for more than two mounts
> and well test, till now we haven't seen any issue.
>
> IMO it should be ready.

Thanks, Xiubo!
It would be awesome to have this in v.6.6.

Kind regards,
Alex

>
> Ilya ?
>
> Thanks
>
> - Xiubo
>
>
> > Kind regards,
> > Alex
> >
> >> 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@kernel.org/
> >>> v2: https://lore.kernel.org/lkml/20230524153316.476973-1-aleksandr.mikhalitsyn@canonical.com/
> >>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v2
> >>> v3: https://lore.kernel.org/lkml/20230607152038.469739-1-aleksandr.mikhalitsyn@canonical.com/#t
> >>> v4: https://lore.kernel.org/lkml/20230607180958.645115-1-aleksandr.mikhalitsyn@canonical.com/#t
> >>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v4
> >>> v5: https://lore.kernel.org/lkml/20230608154256.562906-1-aleksandr.mikhalitsyn@canonical.com/#t
> >>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v5
> >>> v6: https://lore.kernel.org/lkml/20230609093125.252186-1-aleksandr.mikhalitsyn@canonical.com/
> >>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v6
> >>> v7: https://lore.kernel.org/all/20230726141026.307690-1-aleksandr.mikhalitsyn@canonical.com/
> >>> tree: https://github.com/mihalicyn/linux/commits/fs.idmapped.ceph.v7
> >>> v8: https://lore.kernel.org/all/20230803135955.230449-1-aleksandr.mikhalitsyn@canonical.com/
> >>> tree: -
> >>> v9: https://lore.kernel.org/all/20230804084858.126104-1-aleksandr.mikhalitsyn@canonical.com/
> >>> 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(-)
> >>>
>