[v4,0/4] ceph: add support for snapshot names encryption

Message

Luis Henriques April 14, 2022, 1:51 p.m. UTC

Hi!

Time for another iteration on the encrypted snapshots names, which is
mostly a rebase to the wip-fscrypt branch.  To test this, I've used ceph
with the following PRs:

  mds: add protection from clients without fscrypt support #45073
  mds: use the whole string as the snapshot long name #45192
  mds: support alternate names for snapshots #45224
  mds: limit the snapshot names to 240 characters #45312

Changes since v3:

- Fixed WARN_ON() in ceph_encode_encrypted_dname()

- Updated documentation and copyright notice for the base64
  encoding/decoding implementaiton which was taken from the fscrypt base.

Changes since v2:

- Use ceph_find_inode() instead of ceph_get_inode() for finding a snapshot
  parent in function parse_longname().  I've also added a fallback to
  ceph_get_inode() in case we fail to find the inode.  This may happen if,
  for example, the mount root doesn't include that inode.  The iput() was
  also complemented by a discard_new_inode() if the inode is in the I_NEW
  state. (patch 0002)

- Move the check for '_' snapshots further up in the ceph_fname_to_usr()
  and ceph_encode_encrypted_dname().  This fixes the case pointed out by
  Xiubo in v2. (patch 0002)

- Use NAME_MAX for tmp arrays (patch 0002)

- Added an extra patch for replacing the base64url encoding by a different
  encoding standard, the one used for IMAP mailboxes (which uses '+' and
  ',' instead of '-' and '_').  This should fix the issue with snapshot
  names starting with '_'. (patch 0003)

Changes since v1:

- Dropped the dentry->d_flags change in ceph_mkdir().  Thanks to Xiubo
  suggestion, patch 0001 now skips calling ceph_fscrypt_prepare_context()
  if we're handling a snapshot.

- Added error handling to ceph_get_snapdir() in patch 0001 (Jeff had
  already pointed that out but I forgot to include that change in previous
  revision).

- Rebased patch 0002 to the latest wip-fscrypt branch.

- Added some documentation regarding snapshots naming restrictions.


Luís Henriques (4):
  ceph: add support for encrypted snapshot names
  ceph: add support for handling encrypted snapshot names
  ceph: update documentation regarding snapshot naming limitations
  ceph: replace base64url by the encoding used for mailbox names

 Documentation/filesystems/ceph.rst |  10 ++
 fs/ceph/crypto.c                   | 252 +++++++++++++++++++++++++----
 fs/ceph/crypto.h                   |  14 +-
 fs/ceph/dir.c                      |   2 +-
 fs/ceph/inode.c                    |  33 +++-
 5 files changed, 273 insertions(+), 38 deletions(-)

Comments

Xiubo Li April 18, 2022, 2:08 a.m. UTC | #1

On 4/14/22 9:51 PM, Luís Henriques wrote:
> Hi!
>
> Time for another iteration on the encrypted snapshots names, which is
> mostly a rebase to the wip-fscrypt branch.  To test this, I've used ceph
> with the following PRs:
>
>    mds: add protection from clients without fscrypt support #45073
>    mds: use the whole string as the snapshot long name #45192
>    mds: support alternate names for snapshots #45224
>    mds: limit the snapshot names to 240 characters #45312
>
> Changes since v3:
>
> - Fixed WARN_ON() in ceph_encode_encrypted_dname()
>
> - Updated documentation and copyright notice for the base64
>    encoding/decoding implementaiton which was taken from the fscrypt base.
>
> Changes since v2:
>
> - Use ceph_find_inode() instead of ceph_get_inode() for finding a snapshot
>    parent in function parse_longname().  I've also added a fallback to
>    ceph_get_inode() in case we fail to find the inode.  This may happen if,
>    for example, the mount root doesn't include that inode.  The iput() was
>    also complemented by a discard_new_inode() if the inode is in the I_NEW
>    state. (patch 0002)
>
> - Move the check for '_' snapshots further up in the ceph_fname_to_usr()
>    and ceph_encode_encrypted_dname().  This fixes the case pointed out by
>    Xiubo in v2. (patch 0002)
>
> - Use NAME_MAX for tmp arrays (patch 0002)
>
> - Added an extra patch for replacing the base64url encoding by a different
>    encoding standard, the one used for IMAP mailboxes (which uses '+' and
>    ',' instead of '-' and '_').  This should fix the issue with snapshot
>    names starting with '_'. (patch 0003)
>
> Changes since v1:
>
> - Dropped the dentry->d_flags change in ceph_mkdir().  Thanks to Xiubo
>    suggestion, patch 0001 now skips calling ceph_fscrypt_prepare_context()
>    if we're handling a snapshot.
>
> - Added error handling to ceph_get_snapdir() in patch 0001 (Jeff had
>    already pointed that out but I forgot to include that change in previous
>    revision).
>
> - Rebased patch 0002 to the latest wip-fscrypt branch.
>
> - Added some documentation regarding snapshots naming restrictions.
>
>
> Luís Henriques (4):
>    ceph: add support for encrypted snapshot names
>    ceph: add support for handling encrypted snapshot names
>    ceph: update documentation regarding snapshot naming limitations
>    ceph: replace base64url by the encoding used for mailbox names
>
>   Documentation/filesystems/ceph.rst |  10 ++
>   fs/ceph/crypto.c                   | 252 +++++++++++++++++++++++++----
>   fs/ceph/crypto.h                   |  14 +-
>   fs/ceph/dir.c                      |   2 +-
>   fs/ceph/inode.c                    |  33 +++-
>   5 files changed, 273 insertions(+), 38 deletions(-)
>
This patch series LGTM.  Thanks Luis !

Reviewed-by: Xiubo Li <[e-mail]>