Add "drop_writes", "corrupt_bio_byte" and "debug" features to the flakey target. This work was motivated by a need to test the checksum support of the new DM multisnapshot target. I was able to successfully test multisnap checksums with the following: load a previously created multisnapshot pool that has a valid multisnap metadata superblock, when reading write 1 to the 352rd byte of the bio (352 happens to the offset to an unused compat_flags field in 'struct multisnap_super_block; the change causes the multisnap crc code to notice): echo "0 20971520 flakey 254:16 2048 0 5 5 corrupt_bio_byte 352 0 1 debug" | dmsetup create multisnap-metadata echo "0 209715200 multisnap-pool 253:0 253:1 128 32" | dmsetup create pool device-mapper: reload ioctl failed: Cannot allocate memory Command failed (NOTE: I need to cleanup the multisnapshot code so it doesn't throw errors on the floor, checksum failure returns -EILSEQ not -ENOMEM) The kernel log showed: corrupting data bio=ffff88007c8d5140 by writing 1 to byte 352 (rw=0 flags=0 bi_sector=2056 cur_bytes=4096) multisnap sb_check failed csum 4189028790 wanted 227629054 superblock validator check failed for block 0 couldn't lock superblock tm_open_with_sm failed device-mapper: table: 253:2: multisnap-pool: Error creating metadata object device-mapper: ioctl: error adding target to table Mike Snitzer (9): dm: factor out target argument parsing helpers dm flakey: use dm_target_offset() and support discards dm flakey: start of adding features dm flakey: add drop_writes feature dm flakey: add corrupt_bio_byte feature dm flakey: add corrupt_bio_byte read support dm flakey: switch corrupt_bio_data_dir to corrupt_bio_flags dm flakey: add ability to specify the corrupting value to be written dm flakey: add debug feature to control debug output drivers/md/dm-flakey.c | 203 +++++++++++++++++++++++++++++++++++++--- drivers/md/dm-mpath.c | 119 ++++++++----------------- drivers/md/dm-table.c | 40 ++++++++ include/linux/device-mapper.h | 18 ++++ 4 files changed, 282 insertions(+), 98 deletions(-) -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
