Re: [xfsprogs PATCH] xfs_io/encrypt: support specifying crypto data unit size

[Eric Biggers <ebiggers@kernel.org>]

On Thu, Nov 16, 2023 at 11:04:16AM +0100, Carlos Maiolino wrote:
> On Wed, Nov 15, 2023 at 07:58:46PM -0800, Eric Biggers wrote:
> > On Thu, Oct 12, 2023 at 11:26:39PM -0700, Eric Biggers wrote:
> > > From: Eric Biggers <ebiggers@google.com>
> > >
> > > Add an '-s' option to the 'set_encpolicy' command of xfs_io to allow
> > > exercising the log2_data_unit_size field that is being added to struct
> > > fscrypt_policy_v2 (kernel patch:
> > > https://lore.kernel.org/linux-fscrypt/20230925055451.59499-6-ebiggers@kernel.org).
> > >
> > > The xfs_io support is needed for xfstests
> > > (https://lore.kernel.org/fstests/20231013061403.138425-1-ebiggers@kernel.org),
> > > which currently relies on xfs_io to access the encryption ioctls.
> > >
> > > Signed-off-by: Eric Biggers <ebiggers@google.com>
> > > ---
> > >  configure.ac          |  1 +
> > >  include/builddefs.in  |  4 +++
> > >  io/encrypt.c          | 72 ++++++++++++++++++++++++++++++++-----------
> > >  m4/package_libcdev.m4 | 21 +++++++++++++
> > >  man/man8/xfs_io.8     |  5 ++-
> > >  5 files changed, 84 insertions(+), 19 deletions(-)
> > 
> > Hi!  Any feedback on this patch?
> 
> I've got a limited bandwidth these days, I'll try to review this sometime
> around next week.
> 

Thanks Carlos.

BTW, this is really just for xfstests.  To be honest, it might be a good idea to
remove the encryption commands from xfs_io, and make the encryption tests just
use an xfstests helper program, potentially in combination with fscryptctl
(https://github.com/google/fscryptctl) which now contains most of this
functionality too.  Then the XFS folks would have less to worry about.  Maybe
xfs_io has a backwards compatibility guarantee that makes this impossible, but
if not then it may be worth thinking about if the XFS folks don't want to have
to keep reviewing patches to the encryption commands like this.  The xfs_io
commands were what Dave had requested when I added the first encryption tests
back in 2016, so I did it that way, but maybe preferences have changed.

Anyway, review and/or thoughts are appreciated.

- Eric