UPSTREAM: dm verity: add ignore_zero_blocks feature

If ignore_zero_blocks is enabled dm-verity will return zeroes for blocks
matching a zero hash without validating the content.

Bug: 27175947

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Change-Id: Id92e20a8347d4f7846dffbf5bcf326fad3265eca
4 files changed