diff options
| author | Mike Snitzer <snitzer@redhat.com> | 2011-08-02 12:32:06 +0100 |
|---|---|---|
| committer | Alasdair G Kergon <agk@redhat.com> | 2011-08-02 12:32:06 +0100 |
| commit | a3998799fb4df0b0af8271a7d50c4269032397aa (patch) | |
| tree | 2a0dc0a082519afd70cc991da36f620bc21272fe /Documentation/device-mapper/dm-flakey.txt | |
| parent | b26f5e3d7127487e934758c1fbe05d683b082cb0 (diff) | |
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 <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'Documentation/device-mapper/dm-flakey.txt')
| -rw-r--r-- | Documentation/device-mapper/dm-flakey.txt | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/device-mapper/dm-flakey.txt b/Documentation/device-mapper/dm-flakey.txt index 1b66c868ee7..6ff5c232722 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 <Nth_byte> <direction> <value> <flags>: + During <down interval>, replace <Nth_byte> of the data of + each matching bio with <value>. + + <Nth_byte>: The offset of the byte to replace. + Counting starts at 1, to replace the first byte. + <direction>: Either 'r' to corrupt reads or 'w' to corrupt writes. + 'w' is incompatible with drop_writes. + <value>: The value (from 0-255) to write. + <flags>: 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 |