ceph: pass idmap to __ceph_setattr

Just pass down the mount's idmapping to __ceph_setattr,
because we will need it later.

Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: print cluster fsid and client global_id in all debug logs

Multiple CephFS mounts on a host is increasingly common so
disambiguating messages like this is necessary and will make it easier
to debug issues.

At the same this will improve the debug logs to make them easier to
troubleshooting issues, such as print the ino# instead only printing
the memory addresses of the corresponding inodes and print the dentry
names instead of the corresponding memory addresses for the dentry,etc.

Link: https://tracker.ceph.com/issues/61590
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: rename _to_client() to _to_fs_client()

We need to covert the inode to ceph_client in the following commit,
and will add one new helper for that, here we rename the old helper
to _fs_client().

Link: https://tracker.ceph.com/issues/61590
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Patrick Donnelly <pdonnell@redhat.com>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fscrypt: make the bounce page pool opt-in instead of opt-out

Replace FS_CFLG_OWN_PAGES with a bit flag 'needs_bounce_pages' which has
the opposite meaning. I.e., filesystems now opt into the bounce page
pool instead of opt out. Make fscrypt_alloc_bounce_page() check that
the bounce page pool has been initialized.

I believe the opt-in makes more sense, since nothing else in
fscrypt_operations is opt-out, and these days filesystems can choose to
use blk-crypto which doesn't need the fscrypt bounce page pool. Also, I
happen to be planning to add two more flags, and I wanted to fix the
"FS_CFLG_" name anyway as it wasn't prefixed with "FSCRYPT_".

Link: https://lore.kernel.org/r/20230925055451.59499-3-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>

ceph: remove unnecessary IS_ERR() check in ceph_fname_to_usr()

Before returning, function ceph_fname_to_usr() does a final IS_ERR() check
in 'dir':

if ((dir != fname->dir) && !IS_ERR(dir)) {...}

This check is unnecessary because, if the 'dir' variable has changed to
something other than 'fname->dir' (it's initial value), that error check has
been performed already and, if there was indeed an error, it would have
been returned immediately.

Besides, this useless IS_ERR() is also confusing static analysis tools.

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202309282202.xZxGdvS3-lkp@intel.com/
Signed-off-by: Luis Henriques <lhenriques@suse.de>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: remove unnecessary check for NULL in parse_longname()

Function ceph_get_inode() never returns NULL; instead it returns an
ERR_PTR() if something fails. Thus, the check for NULL in parse_longname()
is useless and can be dropped. Instead, move there the debug code that
does the error checking so that it's only executed if ceph_get_inode() is
called.

Fixes: dd66df0053ef ("ceph: add support for encrypted snapshot names")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: add support for encrypted snapshot names

Since filenames in encrypted directories are encrypted and shown as
a base64-encoded string when the directory is locked, make snapshot
names show a similar behaviour.

When creating a snapshot, .snap directories for every subdirectory will
show the snapshot name in the "long format":

# mkdir .snap/my-snap
# ls my-dir/.snap/
_my-snap_1099511627782

Encrypted snapshots will need to be able to handle these by
encrypting/decrypting only the snapshot part of the string ('my-snap').

Also, since the MDS prevents snapshot names to be bigger than 240
characters it is necessary to adapt CEPH_NOHASH_NAME_MAX to accommodate
this extra limitation.

[ idryomov: drop const on !CONFIG_FS_ENCRYPTION branch too ]

Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: add infrastructure for file encryption and decryption

...and allow test_dummy_encryption to bypass content encryption
if mounted with test_dummy_encryption=clear.

[ xiubli: remove test_dummy_encryption=clear support per Ilya ]

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: mark directory as non-complete after loading key

When setting a directory's crypt context, ceph_dir_clear_complete()
needs to be called otherwise if it was complete before, any existing
(old) dentry will still be valid.

This patch adds a wrapper around __fscrypt_prepare_readdir() which will
ensure a directory is marked as non-complete if key status changes.

[ xiubli: revise commit title per Milind ]

Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: add support to readdir for encrypted names

To make it simpler to decrypt names in a readdir reply (i.e. before
we have a dentry), add a new ceph_encode_encrypted_fname()-like helper
that takes a qstr pointer instead of a dentry pointer.

Once we've decrypted the names in a readdir reply, we no longer need the
crypttext, so overwrite them in ceph_mds_reply_dir_entry with the
unencrypted names. Then in both ceph_readdir_prepopulate() and
ceph_readdir() we will use the dencrypted name directly.

[ jlayton: convert some BUG_ONs into error returns ]

Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: add helpers for converting names for userland presentation

Define a new ceph_fname struct that we can use to carry information
about encrypted dentry names. Add helpers for working with these
objects, including ceph_fname_to_usr which formats an encrypted filename
for userland presentation.

[ xiubli: fix resulting name length check -- neither name_len nor
ctext_len should exceed NAME_MAX ]

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: encode encrypted name in ceph_mdsc_build_path and dentry release

Allow ceph_mdsc_build_path to encrypt and base64 encode the filename
when the parent is encrypted and we're sending the path to the MDS. In
a similar fashion, encode encrypted dentry names if including a dentry
release in a request.

In most cases, we just encrypt the filenames and base64 encode them,
but when the name is longer than CEPH_NOHASH_NAME_MAX, we use a similar
scheme to fscrypt proper, and hash the remaning bits with sha256.

When doing this, we then send along the full crypttext of the name in
the new alternate_name field of the MClientRequest. The MDS can then
send that along in readdir responses and traces.

[ idryomov: drop duplicate include reported by Abaci Robot ]

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: add base64 endcoding routines for encrypted names

The base64url encoding used by fscrypt includes the '_' character, which
may cause problems in snapshot names (if the name starts with '_').
Thus, use the base64 encoding defined for IMAP mailbox names (RFC 3501),
which uses '+' and ',' instead of '-' and '_'.

Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: implement -o test_dummy_encryption mount option

Add support for the test_dummy_encryption mount option. This allows us
to test the encrypted codepaths in ceph without having to manually set
keys, etc.

[ lhenriques: fix potential fsc->fsc_dummy_enc_policy memory leak in
ceph_real_mount() ]

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

ceph: fscrypt_auth handling for ceph

Most fscrypt-enabled filesystems store the crypto context in an xattr,
but that's problematic for ceph as xatts are governed by the XATTR cap,
but we really want the crypto context as part of the AUTH cap.

Because of this, the MDS has added two new inode metadata fields:
fscrypt_auth and fscrypt_file. The former is used to hold the crypto
context, and the latter is used to track the real file size.

Parse new fscrypt_auth and fscrypt_file fields in inode traces. For now,
we don't use fscrypt_file, but fscrypt_auth is used to hold the fscrypt
context.

Allow the client to use a setattr request for setting the fscrypt_auth
field. Since this is not a standard setattr request from the VFS, we add
a new field to __ceph_setattr that carries ceph-specific inode attrs.

Have the set_context op do a setattr that sets the fscrypt_auth value,
and get_context just return the contents of that field (since it should
always be available).

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Reviewed-and-tested-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Milind Changire <mchangir@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>