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scsi: don't set tagging state from scsi_adjust_queue_depth

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Remove the tagged argument from scsi_adjust_queue_depth, and just let it
handle the queue depth.  For most drivers those two are fairly separate,
given that most modern drivers don't care about the SCSI "tagged" status
of a command at all, and many old drivers allow queuing of multiple
untagged commands in the driver.

Instead we start out with the ->simple_tags flag set before calling
->slave_configure, which is how all drivers actually looking at
->simple_tags except for one worke anyway.  The one other case looks
broken, but I've kept the behavior as-is for now.

Except for that we only change ->simple_tags from the ->change_queue_type,
and when rejecting a tag message in a single driver, so keeping this
churn out of scsi_adjust_queue_depth is a clear win.

Now that the usage of scsi_adjust_queue_depth is more obvious we can
also remove all the trivial instances in ->slave_alloc or ->slave_configure
that just set it to the cmd_per_lun default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Christoph Hellwig
2014-11-03 20:15:14 +01:00
parent 2ecb204d07
commit c8b09f6fb6
57 changed files with 120 additions and 260 deletions
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25
drivers/scsi/scsi.c
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@@ -744,8 +744,6 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
/**
* scsi_adjust_queue_depth - Let low level drivers change a device's queue depth
* @sdev: SCSI Device in question
* @tagged: Do we use tagged queueing (non-0) or do we treat
* this device as an untagged device (0)
* @tags: Number of tags allowed if tagged queueing enabled,
* or number of commands the low level driver can
* queue up in non-tagged mode (as per cmd_per_lun).
@@ -759,7 +757,7 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
* currently active and whether or not it even has the
* command blocks built yet.
*/
void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
void scsi_adjust_queue_depth(struct scsi_device *sdev, int tags)
{
unsigned long flags;
@@ -787,20 +785,6 @@ void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
}
sdev->queue_depth = tags;
switch (tagged) {
case 0:
sdev->simple_tags = 0;
break;
case MSG_ORDERED_TAG:
case MSG_SIMPLE_TAG:
sdev->simple_tags = 1;
break;
default:
sdev->simple_tags = 0;
sdev_printk(KERN_WARNING, sdev,
"scsi_adjust_queue_depth, bad queue type, "
"disabled\n");
}
out:
spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
}
@@ -848,11 +832,12 @@ int scsi_track_queue_full(struct scsi_device *sdev, int depth)
return 0;
if (sdev->last_queue_full_depth < 8) {
/* Drop back to untagged */
scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
scsi_set_tag_type(sdev, 0);
scsi_adjust_queue_depth(sdev, sdev->host->cmd_per_lun);
return -1;
}
scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
scsi_adjust_queue_depth(sdev, depth);
return depth;
}
EXPORT_SYMBOL(scsi_track_queue_full);
@@ -867,7 +852,7 @@ int scsi_change_queue_type(struct scsi_device *sdev, int tag_type)
if (!sdev->tagged_supported)
return 0;
scsi_adjust_queue_depth(sdev, tag_type, sdev->queue_depth);
scsi_set_tag_type(sdev, tag_type);
return tag_type;
}