Add a parameter to the integritytab file to set the mode in which to
open the integrity volume. The mode can be journaled (the default),
bitmap without a journal, or direct mode without a journal or a bitmap.
This change removes the `no-journal' option because it is redundant,
being replaced with `mode=direct'.
Supercedes commit bcc1ee56c, from a week ago, which implemented
`no-journal'.
Resolves#27587
As documented in integritysetup.8, dm-integrity devices support running
without a journal whatsoever. This change allows the
CRYPT_ACTIVATE_NO_JOURNAL flag (the same as is used with `integritysetup
--integrity-no-journal`) to be passed in during dmsetup by specifying
the `no-journal` option in integritytab.5.
This adds support for dm integrity targets and an associated
/etc/integritytab file which is required as the dm integrity device
super block doesn't include all of the required metadata to bring up
the device correctly. See integritytab man page for details.