On 2020-05-13 22:56, Damien Le Moal wrote: > Currently, a namespace io_opt queue limit is set by default to the > physical sector size of the namespace and to the the write optimal > size (NOWS) when the namespace reports optimal IO sizes. This causes > problems with block limits stacking in blk_stack_limits() when a > namespace block device is combined with an HDD which generally do not > report any optimal transfer size (io_opt limit is 0). The code: Reviewed-by: Bart van Assche <bvanassche@xxxxxxx>