scsi: always assign block layer tags if enabled

Allow a driver to ask for block layer tags by setting .use_blk_tags in the
host template, in which case it will always see a valid value in
request->tag, similar to the behavior when using blk-mq.  This means even
SCSI "untagged" commands will now have a tag, which is especially useful
when using a host-wide tag map.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
This commit is contained in:
Christoph Hellwig
2014-11-03 14:09:02 +01:00
parent e2eddf4d53
commit 2ecb204d07
33 changed files with 86 additions and 168 deletions

View File

@@ -864,16 +864,12 @@ EXPORT_SYMBOL(scsi_track_queue_full);
*/
int scsi_change_queue_type(struct scsi_device *sdev, int tag_type)
{
if (sdev->tagged_supported) {
scsi_set_tag_type(sdev, tag_type);
if (tag_type)
scsi_activate_tcq(sdev, sdev->queue_depth);
else
scsi_deactivate_tcq(sdev, sdev->queue_depth);
} else
tag_type = 0;
if (!sdev->tagged_supported)
return 0;
scsi_adjust_queue_depth(sdev, tag_type, sdev->queue_depth);
return tag_type;
}
EXPORT_SYMBOL(scsi_change_queue_type);