>>>>> "Mike" == Mike Snitzer <snitzer@xxxxxxxxxx> writes: Mike> The math in both blk_stack_limits() and Mike> queue_limit_alignment_offset() assume that a block device's io_min Mike> (aka minimum_io_size) is always a power-of-2. Fix the math such Mike> that it works for non-power-of-2 io_min. Mike> This issue (of alignment_offset != 0) became apparent when testing Mike> dm-thinp with a thinp blocksize that matches a RAID6 stripesize of Mike> 1280K. Commit fdfb4c8c1 ("dm thin: set minimum_io_size to pool's Mike> data block size") unlocked the potential for alignment_offset != 0 Mike> due to the dm-thin-pool's io_min possibly being a non-power-of-2. Looks good to me, Mike. Acked-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> -- Martin K. Petersen Oracle Linux Engineering -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel