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.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/Documentation/device-mapper/verity.txt b/Documentation/device-mapper/verity.txt
index d602c80..89fd8f9 100644
--- a/Documentation/device-mapper/verity.txt
+++ b/Documentation/device-mapper/verity.txt
@@ -79,6 +79,11 @@
not compatible with ignore_corruption and requires user space support to
avoid restart loops.
+ignore_zero_blocks
+ Do not verify blocks that are expected to contain zeroes and always return
+ zeroes instead. This may be useful if the partition contains unused blocks
+ that are not guaranteed to contain zeroes.
+
use_fec_from_device <fec_dev>
Use forward error correction (FEC) to recover from corruption if hash
verification fails. Use encoding data from the specified device. This