From a3998799fb4df0b0af8271a7d50c4269032397aa Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Tue, 2 Aug 2011 12:32:06 +0100 Subject: dm flakey: add corrupt_bio_byte feature Add corrupt_bio_byte feature to simulate corruption by overwriting a byte at a specified position with a specified value during intervals when the device is "down". Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- Documentation/device-mapper/dm-flakey.txt | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) (limited to 'Documentation/device-mapper') diff --git a/Documentation/device-mapper/dm-flakey.txt b/Documentation/device-mapper/dm-flakey.txt index 1b66c868ee7e..6ff5c2327227 100644 --- a/Documentation/device-mapper/dm-flakey.txt +++ b/Documentation/device-mapper/dm-flakey.txt @@ -32,3 +32,22 @@ Optional feature parameters: drop_writes: All write I/O is silently ignored. Read I/O is handled correctly. + + corrupt_bio_byte : + During , replace of the data of + each matching bio with . + + : The offset of the byte to replace. + Counting starts at 1, to replace the first byte. + : Either 'r' to corrupt reads or 'w' to corrupt writes. + 'w' is incompatible with drop_writes. + : The value (from 0-255) to write. + : Perform the replacement only if bio->bi_rw has all the + selected flags set. + +Examples: + corrupt_bio_byte 32 r 1 0 + - replaces the 32nd byte of READ bios with the value 1 + + corrupt_bio_byte 224 w 0 32 + - replaces the 224th byte of REQ_META (=32) bios with the value 0 -- cgit v1.2.3-59-g8ed1b