Re: [PATCH 03/15] scsi: implement reserved command handling

Bart Van Assche
2021-11-26T23:17:12Z

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@acm.org>