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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 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 <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 |