103 Commits

Author	SHA1	Message	Date
Mikulas Patocka	c2bcb2b702	dm integrity: add recovery mode ... 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>	2017-03-24 15:54:23 -04:00
Mike Snitzer	1aa0efd421	dm integrity: factor out create_journal() from dm_integrity_ctr() ... Preparation for next commit that makes call to create_journal() optional. Signed-off-by: Mike Snitzer <snitzer@redhat.com>	2017-03-24 15:54:22 -04:00
Mikulas Patocka	7eada909bf	dm: add integrity target ... 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>	2017-03-24 15:49:07 -04:00