linux-kernel - Re: [f2fs-dev] [PATCH AUTOSEL 5.10 10/31] f2fs: Handle casefolding with Encryption

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Date:   Mon, 4 Jan 2021 09:20:44 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     Eric Biggers <ebiggers@...nel.org>
Cc:     linux-kernel@...r.kernel.org, stable@...r.kernel.org,
        Jaegeuk Kim <jaegeuk@...nel.org>,
        linux-f2fs-devel@...ts.sourceforge.net,
        Daniel Rosenberg <drosen@...gle.com>
Subject: Re: [f2fs-dev] [PATCH AUTOSEL 5.10 10/31] f2fs: Handle casefolding
 with Encryption

On Wed, Dec 30, 2020 at 10:01:56AM -0800, Eric Biggers wrote:
>On Wed, Dec 30, 2020 at 08:02:52AM -0500, Sasha Levin wrote:
>> From: Daniel Rosenberg <drosen@...gle.com>
>>
>> [ Upstream commit 7ad08a58bf67594057362e45cbddd3e27e53e557 ]
>>
>> Expand f2fs's casefolding support to include encrypted directories.  To
>> index casefolded+encrypted directories, we use the SipHash of the
>> casefolded name, keyed by a key derived from the directory's fscrypt
>> master key.  This ensures that the dirhash doesn't leak information
>> about the plaintext filenames.
>>
>> Encryption keys are unavailable during roll-forward recovery, so we
>> can't compute the dirhash when recovering a new dentry in an encrypted +
>> casefolded directory.  To avoid having to force a checkpoint when a new
>> file is fsync'ed, store the dirhash on-disk appended to i_name.
>>
>> This patch incorporates work by Eric Biggers <ebiggers@...gle.com>
>> and Jaegeuk Kim <jaegeuk@...nel.org>.
>>
>> Co-developed-by: Eric Biggers <ebiggers@...gle.com>
>> Signed-off-by: Eric Biggers <ebiggers@...gle.com>
>> Signed-off-by: Daniel Rosenberg <drosen@...gle.com>
>> Reviewed-by: Eric Biggers <ebiggers@...gle.com>
>> Signed-off-by: Jaegeuk Kim <jaegeuk@...nel.org>
>> Signed-off-by: Sasha Levin <sashal@...nel.org>
>
>Please don't backport this to the LTS kernels.  This is a new feature, not a
>fix, and you missed prerequisite patches...

Sure, I'l drop it. Thanks!

-- 
Thanks,
Sasha