On 11/25/21 07:10, Hannes Reinecke wrote:
Quite some drivers are using management commands internally, which typically use the same hardware tag pool (ie they are being allocated from the same hardware resources) as the 'normal' I/O commands. These commands are set aside before allocating the block-mq tag bitmap, so they'll never show up as busy in the tag map. The block-layer, OTOH, already has 'reserved_tags' to handle precisely this situation. So this patch adds a new field 'nr_reserved_cmds' to the SCSI host template to instruct the block layer to set aside a tag space for these management commands by using reserved tags.
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>