linux-ext4 - Re: [PATCH v7 00/10] Set casefold/fscrypt dentry operations through sb->s_d

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Date: Tue, 27 Feb 2024 16:28:23 -0500
From: Gabriel Krisman Bertazi <krisman@...e.de>
To: Eric Biggers <ebiggers@...nel.org>
Cc: viro@...iv.linux.org.uk,  jaegeuk@...nel.org,  tytso@....edu,
  amir73il@...il.com,  linux-ext4@...r.kernel.org,
  linux-f2fs-devel@...ts.sourceforge.net,  linux-fsdevel@...r.kernel.org,
  brauner@...nel.org
Subject: Re: [PATCH v7 00/10] Set casefold/fscrypt dentry operations through
 sb->s_d_op

Eric Biggers <ebiggers@...nel.org> writes:

> On Wed, Feb 21, 2024 at 12:14:02PM -0500, Gabriel Krisman Bertazi wrote:
>> 
>> When case-insensitive and fscrypt were adapted to work together, we moved the
>> code that sets the dentry operations for case-insensitive dentries(d_hash and
>> d_compare) to happen from a helper inside ->lookup.  This is because fscrypt
>> wants to set d_revalidate only on some dentries, so it does it only for them in
>> d_revalidate.
>> 
>> But, case-insensitive hooks are actually set on all dentries in the filesystem,
>> so the natural place to do it is through s_d_op and let d_alloc handle it [1].
>> In addition, doing it inside the ->lookup is a problem for case-insensitive
>> dentries that are not created through ->lookup, like those coming
>> open-by-fhandle[2], which will not see the required d_ops.
>> 
>> This patchset therefore reverts to using sb->s_d_op to set the dentry operations
>> for case-insensitive filesystems.  In order to set case-insensitive hooks early
>> and not require every dentry to have d_revalidate in case-insensitive
>> filesystems, it introduces a patch suggested by Al Viro to disable d_revalidate
>> on some dentries on the fly.
>> 
>> It survives fstests encrypt and quick groups without regressions.  Based on
>> v6.7-rc1.
>> 
>> [1] https://lore.kernel.org/linux-fsdevel/20231123195327.GP38156@ZenIV/
>> [2] https://lore.kernel.org/linux-fsdevel/20231123171255.GN38156@ZenIV/
>> 
>> Gabriel Krisman Bertazi (10):
>>   ovl: Always reject mounting over case-insensitive directories
>>   fscrypt: Factor out a helper to configure the lookup dentry
>>   fscrypt: Drop d_revalidate for valid dentries during lookup
>>   fscrypt: Drop d_revalidate once the key is added
>>   libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
>>   libfs: Add helper to choose dentry operations at mount-time
>>   ext4: Configure dentry operations at dentry-creation time
>>   f2fs: Configure dentry operations at dentry-creation time
>>   ubifs: Configure dentry operations at dentry-creation time
>>   libfs: Drop generic_set_encrypted_ci_d_ops
>> 
>>  fs/crypto/hooks.c       | 15 ++++------
>>  fs/ext4/namei.c         |  1 -
>>  fs/ext4/super.c         |  1 +
>>  fs/f2fs/namei.c         |  1 -
>>  fs/f2fs/super.c         |  1 +
>>  fs/libfs.c              | 62 +++++++++++---------------------------
>>  fs/overlayfs/params.c   | 14 +++++++--
>>  fs/ubifs/dir.c          |  1 -
>>  fs/ubifs/super.c        |  1 +
>>  include/linux/fs.h      | 11 ++++++-
>>  include/linux/fscrypt.h | 66 ++++++++++++++++++++++++++++++++++++-----
>>  11 files changed, 105 insertions(+), 69 deletions(-)
>> 
>
> Looks good,
>
> Reviewed-by: Eric Biggers <ebiggers@...gle.com>

Thank you for you reviews, Eric. I really appreciate them.

Since this been on the list for a while, I pushed it to get some
linux-next testing and, should nothing arise or no one else comments,
will get to Linus soon.

Thanks,

-- 
Gabriel Krisman Bertazi