On Fri, 2018-01-19 at 10:32 +0800, Ming Lei wrote: > Now most of times both NVMe and SCSI won't return BLK_STS_RESOURCE, and > it should be DM-only which returns STS_RESOURCE so often. That's wrong at least for SCSI. See also https://marc.info/?l=linux-block&m=151578329417076. Bart.