From: "Theodore Ts'o" <tytso@mit.edu>
To: Andreas Dilger <adilger@dilger.ca>
Cc: Daniel Rosenberg <drosen@google.com>,
Eric Biggers <ebiggers@kernel.org>,
Andreas Dilger <adilger.kernel@dilger.ca>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
Gabriel Krisman Bertazi <krisman@collabora.com>,
kernel-team@android.com, Paul Lawrence <paullawrence@google.com>
Subject: Re: [PATCH 1/2] ext4: Handle casefolding with encryption
Date: Tue, 9 Feb 2021 18:22:50 -0500 [thread overview]
Message-ID: <YCMZSjgUDtxaVem3@mit.edu> (raw)
In-Reply-To: <YBrP4NXAsvveIpwA@mit.edu>
On Wed, Feb 03, 2021 at 11:31:28AM -0500, Theodore Ts'o wrote:
> On Wed, Feb 03, 2021 at 03:55:06AM -0700, Andreas Dilger wrote:
> >
> > It looks like this change will break the dirdata feature, which is similarly
> > storing a data field beyond the end of the dirent. However, that feature also
> > provides for flags stored in the high bits of the type field to indicate
> > which of the fields are in use there.
> > The first byte of each field stores
> > the length, so it can be skipped even if the content is not understood.
>
> Daniel, for context, the dirdata field is an out-of-tree feature which
> is used by Lustre, and so has fairly large deployed base. So if there
> is a way that we can accomodate not breaking dirdata, that would be
> good.
>
> Did the ext4 casefold+encryption implementation escape out to any
> Android handsets?
So from an OOB chat with Daniel, it appears that the ext4
casefold+encryption implementation did in fact escape out to Android
handsets. So I think what we will need to do, ultiumately, is support
one way of supporting the casefold IV in the case where "encryption &&
casefold", and another way when "encryption && casefold && dirdata".
That's going to be a bit sucky, but I don't think it should be that
complex. Daniel, Andreas, does that make sense to you?
- Ted
next prev parent reply other threads:[~2021-02-10 1:37 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-03 9:07 [PATCH 0/2] Reconcile Encryption and Casefolding in Ext4 Daniel Rosenberg
2021-02-03 9:07 ` [PATCH 1/2] ext4: Handle casefolding with encryption Daniel Rosenberg
[not found] ` <56BC7E2D-A303-45AE-93B6-D8921189F604@dilger.ca>
2021-02-03 16:31 ` Theodore Ts'o
2021-02-09 23:22 ` Theodore Ts'o [this message]
2021-02-10 3:03 ` Andreas Dilger
2021-02-10 4:03 ` Theodore Ts'o
2021-02-17 4:01 ` Daniel Rosenberg
2021-02-17 16:08 ` Theodore Ts'o
2021-02-17 22:48 ` Andreas Dilger
2021-02-18 23:21 ` Daniel Rosenberg
2021-02-26 5:14 ` Andreas Dilger
2021-02-19 15:21 ` Theodore Ts'o
2021-02-03 9:07 ` [PATCH 2/2] ext4: Optimize match for casefolded encrypted dirs Daniel Rosenberg
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