On Mon, Jul 27, 2020 at 12:11:19PM -0700, Ritika Srivastava wrote: > Hence block layer issues write zeroes in blkdev_issue_zeroout() > > In response, the storage returns the following SCSI error > Sense Key : Illegal Request [current] > Add. Sense: Invalid command operation code > > Once this error is received, the write zero capability of the device is disabled and write_zeroes_max_bytes is set to 0. > DM device queue limits are also set to 0 and device-mapper fails the path. > To avoid this, if BLK_STS_NOTSUPP could be returned, then device-mapper would not fail the paths. > > Once the write zero capability has been disabled, blk-lib issues zeroes via __blkdev_issue_zero_pages(). > > Please let me know if I missed something. Oh, the stupid SCSI runtime detection case again. Can you please document this in a comment? Also please switch blk_cloned_rq_check_limits to just return the blk_status_t directly.
