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path: root/drivers/md/dm-verity-target.c
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* dm verity: switch to using asynchronous hash crypto APIGilad Ben-Yossef2017-04-241-60/+141
| | | | | | | | | | | | | | | | | Use of the synchronous digest API limits dm-verity to using pure CPU based algorithm providers and rules out the use of off CPU algorithm providers which are normally asynchronous by nature, potentially freeing CPU cycles. This can reduce performance per Watt in situations such as during boot time when a lot of concurrent file accesses are made to the protected volume. Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com> CC: Eric Biggers <ebiggers3@gmail.com> CC: Ondrej Mosnáček <omosnacek+linux-crypto@gmail.com> Tested-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm verity: fix incorrect error messageEric Biggers2016-11-211-1/+1
| | | | | Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm: rename target's per_bio_data_size to per_io_data_sizeMike Snitzer2016-02-221-6/+6
| | | | | | Request-based DM will also make use of per_bio_data_size. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm verity: add ignore_zero_blocks featureSami Tolvanen2015-12-101-8/+79
| | | | | | | | If ignore_zero_blocks is enabled dm-verity will return zeroes for blocks matching a zero hash without validating the content. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm verity: add support for forward error correctionSami Tolvanen2015-12-101-7/+48
| | | | | | | | | | | | | | | | | | | | | | | | Add support for correcting corrupted blocks using Reed-Solomon. This code uses RS(255, N) interleaved across data and hash blocks. Each error-correcting block covers N bytes evenly distributed across the combined total data, so that each byte is a maximum distance away from the others. This makes it possible to recover from several consecutive corrupted blocks with relatively small space overhead. In addition, using verity hashes to locate erasures nearly doubles the effectiveness of error correction. Being able to detect corrupted blocks also improves performance, because only corrupted blocks need to corrected. For a 2 GiB partition, RS(255, 253) (two parity bytes for each 253-byte block) can correct up to 16 MiB of consecutive corrupted blocks if erasures can be located, and 8 MiB if they cannot, with 16 MiB space overhead. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm verity: factor out verity_for_bv_block()Sami Tolvanen2015-12-101-23/+49
| | | | | | | verity_for_bv_block() will be re-used by optional dm-verity object. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm verity: factor out structures and functions useful to separate objectSami Tolvanen2015-12-101-100/+16
| | | | | | | | Prepare for an optional verity object to make use of existing dm-verity structures and functions. Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
* dm verity: move dm-verity.c to dm-verity-target.cSami Tolvanen2015-12-101-0/+1039
Prepare for extending dm-verity with an optional object. Follows the naming convention used by other DM targets (e.g. dm-cache and dm-era). Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>