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

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Date: Mon, 26 Feb 2024 22:36:14 -0800
From: Eric Biggers <ebiggers@...nel.org>
To: Gabriel Krisman Bertazi <krisman@...e.de>
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

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>

- Eric