[v7,0/8] Support fof Casefolding and Encryption

Message

Daniel Rosenberg Feb. 8, 2020, 1:35 a.m. UTC

These patches are all on top of torvalds/master

Ext4 and F2FS currently both support casefolding and encryption, but not at
the same time. These patches aim to rectify that.

I moved the identical casefolding dcache operations for ext4 and f2fs into
fs/libfs.c, as all filesystems using casefolded names will want them.

I've also adjust fscrypt to not set it's d_revalidate operation during it's
prepare lookup, instead having the calling filesystem set it up. This is
done to that the filesystem may have it's own dentry_operations. Also added
a helper function in libfs.c that will work for filesystems supporting both
casefolding and fscrypt.

For Ext4, since the hash for encrypted casefolded directory names cannot be
computed without the key, we need to store the hash on disk. We only do so
for encrypted and casefolded directories to avoid on disk format changes.
Previously encryption and casefolding could not be on the same filesystem,
and we're relaxing that requirement. F2fs is a bit more straightforward
since it already stores hashes on disk.

I've updated the related tools with just enough to enable the feature. I
still need to adjust ext4's fsck's, although without access to the keys,
neither fsck will be able to verify the hashes of casefolded and encrypted
names.

v7 chances:
Moved dentry operations from unicode to libfs, added new iterator function
to unicode to allow this.
Added libfs function for setting dentries to remove code duplication between
ext4 and f2fs.

v6 changes:
Went back to using dentry_operations for casefolding. Provided standard
implementations in fs/unicode, avoiding extra allocation in d_hash op.
Moved fscrypt d_ops setting to be filesystem's responsibility to maintain
compatibility with casefolding and overlayfs if casefolding is not used
fixes some f2fs error handling

v4-5: patches submitted on fscrypt

v3 changes:
fscrypt patch only creates hash key if it will be needed.
Rebased on top of fscrypt branch, reconstified match functions in ext4/f2fs

v2 changes:
fscrypt moved to separate thread to rebase on fscrypt dev branch
addressed feedback, plus some minor fixes


Daniel Rosenberg (8):
  unicode: Add utf8_casefold_iter
  fs: Add standard casefolding support
  f2fs: Use generic casefolding support
  ext4: Use generic casefolding support
  fscrypt: Have filesystems handle their d_ops
  f2fs: Handle casefolding with Encryption
  ext4: Hande casefolding with encryption
  ext4: Optimize match for casefolded encrypted dirs

 Documentation/filesystems/ext4/directory.rst |  27 ++
 fs/crypto/fname.c                            |   7 +-
 fs/crypto/fscrypt_private.h                  |   1 -
 fs/crypto/hooks.c                            |   1 -
 fs/ext4/dir.c                                |  78 +----
 fs/ext4/ext4.h                               |  93 ++++--
 fs/ext4/hash.c                               |  26 +-
 fs/ext4/ialloc.c                             |   5 +-
 fs/ext4/inline.c                             |  41 ++-
 fs/ext4/namei.c                              | 325 ++++++++++++-------
 fs/ext4/super.c                              |  21 +-
 fs/f2fs/dir.c                                | 127 +++-----
 fs/f2fs/f2fs.h                               |  15 +-
 fs/f2fs/hash.c                               |  25 +-
 fs/f2fs/inline.c                             |   9 +-
 fs/f2fs/namei.c                              |   1 +
 fs/f2fs/super.c                              |  17 +-
 fs/f2fs/sysfs.c                              |  10 +-
 fs/libfs.c                                   | 127 ++++++++
 fs/ubifs/dir.c                               |  18 +
 fs/unicode/utf8-core.c                       |  25 +-
 include/linux/f2fs_fs.h                      |   3 -
 include/linux/fs.h                           |  24 ++
 include/linux/fscrypt.h                      |   6 +-
 include/linux/unicode.h                      |  10 +
 25 files changed, 671 insertions(+), 371 deletions(-)

Comments

Eric Biggers Feb. 12, 2020, 6:12 a.m. UTC | #1

On Fri, Feb 07, 2020 at 05:35:44PM -0800, Daniel Rosenberg wrote:
> Support fof Casefolding and Encryption

You should fix the typo in the subject in the next version.  I assumed you'd
notice, but both v6 and v7 have this...

- Eric

Daniel Rosenberg Feb. 13, 2020, 12:01 a.m. UTC | #2

On Tue, Feb 11, 2020 at 10:12 PM Eric Biggers <[e-mail]> wrote:
>
> On Fri, Feb 07, 2020 at 05:35:44PM -0800, Daniel Rosenberg wrote:
> > Support fof Casefolding and Encryption
>
> You should fix the typo in the subject in the next version.  I assumed you'd
> notice, but both v6 and v7 have this...
>
> - Eric

Yeah, noticed just after I sent v7 :'(