Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx> --- Documentation/device-mapper/dm-flakey.txt | 15 ++++++++++++++- 1 files changed, 14 insertions(+), 1 deletions(-) diff --git a/Documentation/device-mapper/dm-flakey.txt b/Documentation/device-mapper/dm-flakey.txt index 6b40f79..6b4df49 100644 --- a/Documentation/device-mapper/dm-flakey.txt +++ b/Documentation/device-mapper/dm-flakey.txt @@ -27,7 +27,20 @@ Mandatory parameters: Optional feature parameters: If no feature parameters are present, during the periods of - unreliability, all I/O returns errors. + unreliability, all I/O returns errors. Optional features may be + combined (e.g. corrupt_bio_byte on READ and drop_writes). Conflicting + features (e.g. corrupt_bio_byte on WRITE and drop_writes) are resolved + according to the following feature precedence (descending order): + + corrupt_bio_byte <Nth byte> <bio_flags> <value>: + Corrupt bios that have specific bi_rw flag(s), e.g.: READ=0 or + REQ_WRITE=1|REQ_META=32, by writing <value> to the <Nth byte> of + bios that have data. + Examples: + 1) corrupt 32nd byte in READ bios with the value 1: + corrupt_bio_byte 32 0 1 + 2) corrupt 224th byte in WRITE|REQ_META bios with the value 0: + corrupt_bio_byte 224 33 0 drop_writes: All write I/O is silently ignored. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
