linux-ext4 - Re: [PATCH] e2fsck: allow verity files to have initialized blocks past i

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Message-ID: <20180821202352.GF4723@thunk.org>
Date:   Tue, 21 Aug 2018 16:23:52 -0400
From:   "Theodore Y. Ts'o" <tytso@....edu>
To:     Eric Biggers <ebiggers@...nel.org>
Cc:     linux-ext4@...r.kernel.org
Subject: Re: [PATCH] e2fsck: allow verity files to have initialized blocks
 past i_size

On Tue, Aug 21, 2018 at 10:59:37AM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@...gle.com>
> 
> Since ext4 verity is going to be an RO_COMPAT feature rather than an
> INCOMPAT one, the on-disk i_size of verity inodes needs to be the data
> size rather than the full size.  Consequently, verity inodes will have
> initialized blocks past i_size, containing the Merkle tree and other
> verity metadata.  So e2fsck must not fix the i_size of such inodes as it
> normally would.
> 
> Signed-off-by: Eric Biggers <ebiggers@...gle.com>

Thanks, applied.

We should have some tests, in e2fsprogs and/or xfstests that tests
this.  The work-in-progress verity 9XX xfstests don't seem to have a
problem with this, probably because we weren't unmounting a file
system, and then running fsck.  (Since it's a scratch partition,
the test harness doesn't run fsck after any of the 9XX tests.)

Thanks for catching this!

				- Ted