Some coding style changes.
Fix a bug that the array test_tag has insufficient size if the digest
size of internal has is bigger than the tag size.
The function __fls is undefined for zero argument, this patch fixes
undefined behavior if the user sets zero interleave_sectors.
Fix the limit of optional arguments to 8.
Don't allocate crypt_data on the stack to avoid a BUG with debug kernel.
Rename all optional argument names to have underscores rather than
dashes.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
In recovery mode, we don't:
- replay the journal
- check checksums
- allow writes to the device
This mode can be used as a last resort for data recovery. The
motivation for recovery mode is that when there is a single error in the
journal, the user should not lose access to the whole device.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The dm-integrity target emulates a block device that has additional
per-sector tags that can be used for storing integrity information.
A general problem with storing integrity tags with every sector is that
writing the sector and the integrity tag must be atomic - i.e. in case of
crash, either both sector and integrity tag or none of them is written.
To guarantee write atomicity the dm-integrity target uses a journal. It
writes sector data and integrity tags into a journal, commits the journal
and then copies the data and integrity tags to their respective location.
The dm-integrity target can be used with the dm-crypt target - in this
situation the dm-crypt target creates the integrity data and passes them
to the dm-integrity target via bio_integrity_payload attached to the bio.
In this mode, the dm-crypt and dm-integrity targets provide authenticated
disk encryption - if the attacker modifies the encrypted device, an I/O
error is returned instead of random data.
The dm-integrity target can also be used as a standalone target, in this
mode it calculates and verifies the integrity tag internally. In this
mode, the dm-integrity target can be used to detect silent data
corruption on the disk or in the I/O path.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Milan Broz <gmazyland@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Mikulas Patocka