queue_type fixups

queue_type fixups

[Christoph Hellwig]

These are a few patches that follow up my previous cleanups for the
queue depth and type handling.

The first patch removes the now pointless write support for the queue_type
sysfs attribute.  The second changes the queue full tracking code to
never drop out of tagged mode, as we can't recover from that, and the
last two are random cleanups.

[PATCH 1/4] scsi: remove ->change_queue_type method

[Christoph Hellwig]

Since we got rid of ordered tag support in 2010 the prime use case of
switching on and off ordered tags has been obsolete.  The other function
of enabling/dsiabling tagging entirely has only been correctly implemented
by the 53c700 driver and isn't generally useful.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/infiniband/ulp/srp/ib_srp.c  |  1 -
 drivers/scsi/53c700.c                | 35 -----------------------------------
 drivers/scsi/aic94xx/aic94xx_init.c  |  1 -
 drivers/scsi/bnx2fc/bnx2fc_fcoe.c    |  1 -
 drivers/scsi/esas2r/esas2r_main.c    |  1 -
 drivers/scsi/fcoe/fcoe.c             |  1 -
 drivers/scsi/fnic/fnic_main.c        |  1 -
 drivers/scsi/ibmvscsi/ibmvfc.c       |  1 -
 drivers/scsi/ipr.c                   | 25 -------------------------
 drivers/scsi/isci/init.c             |  1 -
 drivers/scsi/libsas/sas_scsi_host.c  |  8 --------
 drivers/scsi/lpfc/lpfc_scsi.c        |  2 --
 drivers/scsi/mpt2sas/mpt2sas_scsih.c |  1 -
 drivers/scsi/mpt3sas/mpt3sas_scsih.c |  1 -
 drivers/scsi/mvsas/mv_init.c         |  1 -
 drivers/scsi/pm8001/pm8001_init.c    |  1 -
 drivers/scsi/pmcraid.c               |  1 -
 drivers/scsi/qla2xxx/qla_os.c        |  1 -
 drivers/scsi/scsi.c                  | 16 ----------------
 drivers/scsi/scsi_debug.c            | 27 ---------------------------
 drivers/scsi/scsi_sysfs.c            | 30 ++++--------------------------
 drivers/target/loopback/tcm_loop.c   |  1 -
 include/scsi/libsas.h                |  1 -
 include/scsi/scsi_host.h             | 13 -------------
 include/scsi/scsi_tcq.h              |  3 ---
 25 files changed, 4 insertions(+), 171 deletions(-)

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 5461924..a164036 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -2740,7 +2740,6 @@ static struct scsi_host_template srp_template = {
 	.info				= srp_target_info,
 	.queuecommand			= srp_queuecommand,
 	.change_queue_depth             = srp_change_queue_depth,
-	.change_queue_type              = scsi_change_queue_type,
 	.eh_abort_handler		= srp_abort,
 	.eh_device_reset_handler	= srp_reset_device,
 	.eh_host_reset_handler		= srp_reset_host,
diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
index aa915da..e722911 100644
--- a/drivers/scsi/53c700.c
+++ b/drivers/scsi/53c700.c
@@ -176,7 +176,6 @@ STATIC int NCR_700_slave_alloc(struct scsi_device *SDpnt);
 STATIC int NCR_700_slave_configure(struct scsi_device *SDpnt);
 STATIC void NCR_700_slave_destroy(struct scsi_device *SDpnt);
 static int NCR_700_change_queue_depth(struct scsi_device *SDpnt, int depth);
-static int NCR_700_change_queue_type(struct scsi_device *SDpnt, int depth);
 
 STATIC struct device_attribute *NCR_700_dev_attrs[];
 
@@ -326,7 +325,6 @@ NCR_700_detect(struct scsi_host_template *tpnt,
 	tpnt->slave_destroy = NCR_700_slave_destroy;
 	tpnt->slave_alloc = NCR_700_slave_alloc;
 	tpnt->change_queue_depth = NCR_700_change_queue_depth;
-	tpnt->change_queue_type = NCR_700_change_queue_type;
 	tpnt->use_blk_tags = 1;
 
 	if(tpnt->name == NULL)
@@ -2082,39 +2080,6 @@ NCR_700_change_queue_depth(struct scsi_device *SDp, int depth)
 	return scsi_change_queue_depth(SDp, depth);
 }
 
-static int NCR_700_change_queue_type(struct scsi_device *SDp, int tag_type)
-{
-	int change_tag = ((tag_type ==0 &&  scsi_get_tag_type(SDp) != 0)
-			  || (tag_type != 0 && scsi_get_tag_type(SDp) == 0));
-	struct NCR_700_Host_Parameters *hostdata = 
-		(struct NCR_700_Host_Parameters *)SDp->host->hostdata[0];
-
-	/* We have a global (per target) flag to track whether TCQ is
-	 * enabled, so we'll be turning it off for the entire target here.
-	 * our tag algorithm will fail if we mix tagged and untagged commands,
-	 * so quiesce the device before doing this */
-	if (change_tag)
-		scsi_target_quiesce(SDp->sdev_target);
-
-	scsi_set_tag_type(SDp, tag_type);
-	if (!tag_type) {
-		/* shift back to the default unqueued number of commands
-		 * (the user can still raise this) */
-		scsi_change_queue_depth(SDp, SDp->host->cmd_per_lun);
-		hostdata->tag_negotiated &= ~(1 << sdev_id(SDp));
-	} else {
-		/* Here, we cleared the negotiation flag above, so this
-		 * will force the driver to renegotiate */
-		scsi_change_queue_depth(SDp, SDp->queue_depth);
-		if (change_tag)
-			NCR_700_set_tag_neg_state(SDp, NCR_700_START_TAG_NEGOTIATION);
-	}
-	if (change_tag)
-		scsi_target_resume(SDp->sdev_target);
-
-	return tag_type;
-}
-
 static ssize_t
 NCR_700_show_active_tags(struct device *dev, struct device_attribute *attr, char *buf)
 {
diff --git a/drivers/scsi/aic94xx/aic94xx_init.c b/drivers/scsi/aic94xx/aic94xx_init.c
index a64cf93..617ee73 100644
--- a/drivers/scsi/aic94xx/aic94xx_init.c
+++ b/drivers/scsi/aic94xx/aic94xx_init.c
@@ -71,7 +71,6 @@ static struct scsi_host_template aic94xx_sht = {
 	.scan_finished		= asd_scan_finished,
 	.scan_start		= asd_scan_start,
 	.change_queue_depth	= sas_change_queue_depth,
-	.change_queue_type	= sas_change_queue_type,
 	.bios_param		= sas_bios_param,
 	.can_queue		= 1,
 	.cmd_per_lun		= 1,
diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
index 386c2cf..17a29e9 100644
--- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
+++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c
@@ -2785,7 +2785,6 @@ static struct scsi_host_template bnx2fc_shost_template = {
 	.eh_host_reset_handler	= fc_eh_host_reset,
 	.slave_alloc		= fc_slave_alloc,
 	.change_queue_depth	= scsi_change_queue_depth,
-	.change_queue_type	= scsi_change_queue_type,
 	.this_id		= -1,
 	.cmd_per_lun		= 3,
 	.use_clustering		= ENABLE_CLUSTERING,
diff --git a/drivers/scsi/esas2r/esas2r_main.c b/drivers/scsi/esas2r/esas2r_main.c
index 593ff8a..7e1c21e 100644
--- a/drivers/scsi/esas2r/esas2r_main.c
+++ b/drivers/scsi/esas2r/esas2r_main.c
@@ -255,7 +255,6 @@ static struct scsi_host_template driver_template = {
 	.emulated			= 0,
 	.proc_name			= ESAS2R_DRVR_NAME,
 	.change_queue_depth		= scsi_change_queue_depth,
-	.change_queue_type		= scsi_change_queue_type,
 	.max_sectors			= 0xFFFF,
 	.use_blk_tags			= 1,
 };
diff --git a/drivers/scsi/fcoe/fcoe.c b/drivers/scsi/fcoe/fcoe.c
index 308a016..49df213 100644
--- a/drivers/scsi/fcoe/fcoe.c
+++ b/drivers/scsi/fcoe/fcoe.c
@@ -281,7 +281,6 @@ static struct scsi_host_template fcoe_shost_template = {
 	.eh_host_reset_handler = fc_eh_host_reset,
 	.slave_alloc = fc_slave_alloc,
 	.change_queue_depth = scsi_change_queue_depth,
-	.change_queue_type = scsi_change_queue_type,
 	.this_id = -1,
 	.cmd_per_lun = 3,
 	.can_queue = FCOE_MAX_OUTSTANDING_COMMANDS,
diff --git a/drivers/scsi/fnic/fnic_main.c b/drivers/scsi/fnic/fnic_main.c
index 0c1f817..8a0d4d7 100644
--- a/drivers/scsi/fnic/fnic_main.c
+++ b/drivers/scsi/fnic/fnic_main.c
@@ -111,7 +111,6 @@ static struct scsi_host_template fnic_host_template = {
 	.eh_host_reset_handler = fnic_host_reset,
 	.slave_alloc = fnic_slave_alloc,
 	.change_queue_depth = scsi_change_queue_depth,
-	.change_queue_type = scsi_change_queue_type,
 	.this_id = -1,
 	.cmd_per_lun = 3,
 	.can_queue = FNIC_DFLT_IO_REQ,
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index f58c6d8..6e35964 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -3089,7 +3089,6 @@ static struct scsi_host_template driver_template = {
 	.target_alloc = ibmvfc_target_alloc,
 	.scan_finished = ibmvfc_scan_finished,
 	.change_queue_depth = ibmvfc_change_queue_depth,
-	.change_queue_type = scsi_change_queue_type,
 	.cmd_per_lun = 16,
 	.can_queue = IBMVFC_MAX_REQUESTS_DEFAULT,
 	.this_id = -1,
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index 5402943..c35ef5f 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -4346,30 +4346,6 @@ static int ipr_change_queue_depth(struct scsi_device *sdev, int qdepth)
 }
 
 /**
- * ipr_change_queue_type - Change the device's queue type
- * @dsev:		scsi device struct
- * @tag_type:	type of tags to use
- *
- * Return value:
- * 	actual queue type set
- **/
-static int ipr_change_queue_type(struct scsi_device *sdev, int tag_type)
-{
-	struct ipr_ioa_cfg *ioa_cfg = (struct ipr_ioa_cfg *)sdev->host->hostdata;
-	struct ipr_resource_entry *res;
-	unsigned long lock_flags = 0;
-
-	spin_lock_irqsave(ioa_cfg->host->host_lock, lock_flags);
-	res = (struct ipr_resource_entry *)sdev->hostdata;
-	if (res && ipr_is_gscsi(res))
-		tag_type = scsi_change_queue_type(sdev, tag_type);
-	else
-		tag_type = 0;
-	spin_unlock_irqrestore(ioa_cfg->host->host_lock, lock_flags);
-	return tag_type;
-}
-
-/**
  * ipr_show_adapter_handle - Show the adapter's resource handle for this device
  * @dev:	device struct
  * @attr:	device attribute structure
@@ -6302,7 +6278,6 @@ static struct scsi_host_template driver_template = {
 	.target_alloc = ipr_target_alloc,
 	.target_destroy = ipr_target_destroy,
 	.change_queue_depth = ipr_change_queue_depth,
-	.change_queue_type = ipr_change_queue_type,
 	.bios_param = ipr_biosparam,
 	.can_queue = IPR_MAX_COMMANDS,
 	.this_id = -1,
diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c
index a81e546..4a93002 100644
--- a/drivers/scsi/isci/init.c
+++ b/drivers/scsi/isci/init.c
@@ -158,7 +158,6 @@ static struct scsi_host_template isci_sht = {
 	.scan_finished			= isci_host_scan_finished,
 	.scan_start			= isci_host_start,
 	.change_queue_depth		= sas_change_queue_depth,
-	.change_queue_type		= sas_change_queue_type,
 	.bios_param			= sas_bios_param,
 	.can_queue			= ISCI_CAN_QUEUE_VAL,
 	.cmd_per_lun			= 1,
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index b492293..8f32ec1 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -965,13 +965,6 @@ int sas_change_queue_depth(struct scsi_device *sdev, int depth)
 	return scsi_change_queue_depth(sdev, depth);
 }
 
-int sas_change_queue_type(struct scsi_device *scsi_dev, int type)
-{
-	if (dev_is_sata(sdev_to_domain_dev(scsi_dev)))
-		return -EINVAL;
-	return scsi_change_queue_type(scsi_dev, type);
-}
-
 int sas_bios_param(struct scsi_device *scsi_dev,
 			  struct block_device *bdev,
 			  sector_t capacity, int *hsc)
@@ -1185,7 +1178,6 @@ EXPORT_SYMBOL_GPL(sas_queuecommand);
 EXPORT_SYMBOL_GPL(sas_target_alloc);
 EXPORT_SYMBOL_GPL(sas_slave_configure);
 EXPORT_SYMBOL_GPL(sas_change_queue_depth);
-EXPORT_SYMBOL_GPL(sas_change_queue_type);
 EXPORT_SYMBOL_GPL(sas_bios_param);
 EXPORT_SYMBOL_GPL(sas_task_abort);
 EXPORT_SYMBOL_GPL(sas_phy_reset);
diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index fd85952..4f9222e 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -5879,7 +5879,6 @@ struct scsi_host_template lpfc_template = {
 	.max_sectors		= 0xFFFF,
 	.vendor_id		= LPFC_NL_VENDOR_ID,
 	.change_queue_depth	= scsi_change_queue_depth,
-	.change_queue_type	= scsi_change_queue_type,
 	.use_blk_tags		= 1,
 	.track_queue_depth	= 1,
 };
@@ -5904,7 +5903,6 @@ struct scsi_host_template lpfc_vport_template = {
 	.shost_attrs		= lpfc_vport_attrs,
 	.max_sectors		= 0xFFFF,
 	.change_queue_depth	= scsi_change_queue_depth,
-	.change_queue_type	= scsi_change_queue_type,
 	.use_blk_tags		= 1,
 	.track_queue_depth	= 1,
 };
diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
index 8431eb1..6a1c036 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c
@@ -7592,7 +7592,6 @@ static struct scsi_host_template scsih_driver_template = {
 	.scan_finished			= _scsih_scan_finished,
 	.scan_start			= _scsih_scan_start,
 	.change_queue_depth 		= _scsih_change_queue_depth,
-	.change_queue_type		= scsi_change_queue_type,
 	.eh_abort_handler		= _scsih_abort,
 	.eh_device_reset_handler	= _scsih_dev_reset,
 	.eh_target_reset_handler	= _scsih_target_reset,
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index a2b6099..94261ee 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -7229,7 +7229,6 @@ static struct scsi_host_template scsih_driver_template = {
 	.scan_finished			= _scsih_scan_finished,
 	.scan_start			= _scsih_scan_start,
 	.change_queue_depth		= _scsih_change_queue_depth,
-	.change_queue_type		= scsi_change_queue_type,
 	.eh_abort_handler		= _scsih_abort,
 	.eh_device_reset_handler	= _scsih_dev_reset,
 	.eh_target_reset_handler	= _scsih_target_reset,
diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c
index ac7c030..3cc89be 100644
--- a/drivers/scsi/mvsas/mv_init.c
+++ b/drivers/scsi/mvsas/mv_init.c
@@ -63,7 +63,6 @@ static struct scsi_host_template mvs_sht = {
 	.scan_finished		= mvs_scan_finished,
 	.scan_start		= mvs_scan_start,
 	.change_queue_depth	= sas_change_queue_depth,
-	.change_queue_type	= sas_change_queue_type,
 	.bios_param		= sas_bios_param,
 	.can_queue		= 1,
 	.cmd_per_lun		= 1,
diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index 19ae6ca..134e049 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -76,7 +76,6 @@ static struct scsi_host_template pm8001_sht = {
 	.scan_finished		= pm8001_scan_finished,
 	.scan_start		= pm8001_scan_start,
 	.change_queue_depth	= sas_change_queue_depth,
-	.change_queue_type	= sas_change_queue_type,
 	.bios_param		= sas_bios_param,
 	.can_queue		= 1,
 	.cmd_per_lun		= 1,
diff --git a/drivers/scsi/pmcraid.c b/drivers/scsi/pmcraid.c
index b1b1f66..8c27b6a 100644
--- a/drivers/scsi/pmcraid.c
+++ b/drivers/scsi/pmcraid.c
@@ -4251,7 +4251,6 @@ static struct scsi_host_template pmcraid_host_template = {
 	.slave_configure = pmcraid_slave_configure,
 	.slave_destroy = pmcraid_slave_destroy,
 	.change_queue_depth = pmcraid_change_queue_depth,
-	.change_queue_type  = scsi_change_queue_type,
 	.can_queue = PMCRAID_MAX_IO_CMD,
 	.this_id = -1,
 	.sg_tablesize = PMCRAID_MAX_IOADLS,
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 6b4d923..12ca291 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -258,7 +258,6 @@ struct scsi_host_template qla2xxx_driver_template = {
 	.scan_finished		= qla2xxx_scan_finished,
 	.scan_start		= qla2xxx_scan_start,
 	.change_queue_depth	= scsi_change_queue_depth,
-	.change_queue_type	= scsi_change_queue_type,
 	.this_id		= -1,
 	.cmd_per_lun		= 3,
 	.use_clustering		= ENABLE_CLUSTERING,
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 5ea15fc..72282ae 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -832,22 +832,6 @@ int scsi_track_queue_full(struct scsi_device *sdev, int depth)
 EXPORT_SYMBOL(scsi_track_queue_full);
 
 /**
- * scsi_change_queue_type() - Change a device's queue type
- * @sdev:     The SCSI device whose queue depth is to change
- * @tag_type: Identifier for queue type
- */
-int scsi_change_queue_type(struct scsi_device *sdev, int tag_type)
-{
-	if (!sdev->tagged_supported)
-		return 0;
-
-	scsi_set_tag_type(sdev, tag_type);
-	return tag_type;
-
-}
-EXPORT_SYMBOL(scsi_change_queue_type);
-
-/**
  * scsi_vpd_inquiry - Request a device provide us with a VPD page
  * @sdev: The device to ask
  * @buffer: Where to put the result
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index ce71b6d..169c84f 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -4499,32 +4499,6 @@ sdebug_change_qdepth(struct scsi_device *sdev, int qdepth)
 	return sdev->queue_depth;
 }
 
-static int
-sdebug_change_qtype(struct scsi_device *sdev, int qtype)
-{
-	qtype = scsi_change_queue_type(sdev, qtype);
-	if (SCSI_DEBUG_OPT_Q_NOISE & scsi_debug_opts) {
-		const char *cp;
-
-		switch (qtype) {
-		case 0:
-			cp = "untagged";
-			break;
-		case MSG_SIMPLE_TAG:
-			cp = "simple tags";
-			break;
-		case MSG_ORDERED_TAG:
-			cp = "ordered tags";
-			break;
-		default:
-			cp = "unknown";
-			break;
-		}
-		sdev_printk(KERN_INFO, sdev, "%s: to %s\n", __func__, cp);
-	}
-	return qtype;
-}
-
 static struct scsi_host_template sdebug_driver_template = {
 	.show_info =		scsi_debug_show_info,
 	.write_info =		scsi_debug_write_info,
@@ -4537,7 +4511,6 @@ static struct scsi_host_template sdebug_driver_template = {
 	.ioctl =		scsi_debug_ioctl,
 	.queuecommand =		sdebug_queuecommand_lock_or_not,
 	.change_queue_depth =	sdebug_change_qdepth,
-	.change_queue_type =	sdebug_change_qtype,
 	.eh_abort_handler =	scsi_debug_abort,
 	.eh_device_reset_handler = scsi_debug_device_reset,
 	.eh_target_reset_handler = scsi_debug_target_reset,
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 1cb64a8..1ac38e7 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -738,30 +738,12 @@ store_queue_type_field(struct device *dev, struct device_attribute *attr,
 		       const char *buf, size_t count)
 {
 	struct scsi_device *sdev = to_scsi_device(dev);
-	struct scsi_host_template *sht = sdev->host->hostt;
-	int tag_type = 0, retval;
-	int prev_tag_type = scsi_get_tag_type(sdev);
-
-	if (!sdev->tagged_supported || !sht->change_queue_type)
-		return -EINVAL;
 
-	/*
-	 * We're never issueing order tags these days, but allow the value
-	 * for backwards compatibility.
-	 */
-	if (strncmp(buf, "ordered", 7) == 0 ||
-	    strncmp(buf, "simple", 6) == 0)
-		tag_type = MSG_SIMPLE_TAG;
-	else if (strncmp(buf, "none", 4) != 0)
+	if (!sdev->tagged_supported)
 		return -EINVAL;
-
-	if (tag_type == prev_tag_type)
-		return count;
-
-	retval = sht->change_queue_type(sdev, tag_type);
-	if (retval < 0)
-		return retval;
-
+		
+	sdev_printk(KERN_INFO, sdev,
+		    "ignoring write to deprecated queue_type attribute");
 	return count;
 }
 
@@ -938,10 +920,6 @@ static umode_t scsi_sdev_attr_is_visible(struct kobject *kobj,
 	    !sdev->host->hostt->change_queue_depth)
 		return 0;
 
-	if (attr == &dev_attr_queue_type.attr &&
-	    !sdev->host->hostt->change_queue_type)
-		return S_IRUGO;
-
 	return attr->mode;
 }
 
diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 4d1b722..24e2c94 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -385,7 +385,6 @@ static struct scsi_host_template tcm_loop_driver_template = {
 	.name			= "TCM_Loopback",
 	.queuecommand		= tcm_loop_queuecommand,
 	.change_queue_depth	= scsi_change_queue_depth,
-	.change_queue_type	= scsi_change_queue_type,
 	.eh_abort_handler = tcm_loop_abort_task,
 	.eh_device_reset_handler = tcm_loop_device_reset,
 	.eh_target_reset_handler = tcm_loop_target_reset,
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 1f8b33e..6afabbc 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -705,7 +705,6 @@ extern int sas_queuecommand(struct Scsi_Host * ,struct scsi_cmnd *);
 extern int sas_target_alloc(struct scsi_target *);
 extern int sas_slave_configure(struct scsi_device *);
 extern int sas_change_queue_depth(struct scsi_device *, int new_depth);
-extern int sas_change_queue_type(struct scsi_device *, int qt);
 extern int sas_bios_param(struct scsi_device *,
 			  struct block_device *,
 			  sector_t capacity, int *hsc);
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index c8a462e..c2fa8b4 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -278,19 +278,6 @@ struct scsi_host_template {
 	int (* change_queue_depth)(struct scsi_device *, int);
 
 	/*
-	 * Fill in this function to allow the changing of tag types
-	 * (this also allows the enabling/disabling of tag command
-	 * queueing).  An error should only be returned if something
-	 * went wrong in the driver while trying to set the tag type.
-	 * If the driver doesn't support the requested tag type, then
-	 * it should set the closest type it does support without
-	 * returning an error.  Returns the actual tag type set.
-	 *
-	 * Status: OPTIONAL
-	 */
-	int (* change_queue_type)(struct scsi_device *, int);
-
-	/*
 	 * This function determines the BIOS parameters for a given
 	 * harddisk.  These tend to be numbers that are made up by
 	 * the host adapter.  Parameters:
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index fe4a702..59578be 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -15,9 +15,6 @@
 
 
 #ifdef CONFIG_BLOCK
-
-int scsi_change_queue_type(struct scsi_device *sdev, int tag_type);
-
 /**
  * scsi_get_tag_type - get the type of tag the device supports
  * @sdev:	the scsi device
-- 
1.9.1

[PATCH 2/4] scsi: never drop to untagged mode during queue ramp down

[Christoph Hellwig]

Dropping to untagged mode when ramping down a queue due to QUEUE FULL
events has two problems:

 - nothing in the midlayer or drivers ever moves back to tagged mode
   during queue ramp up.
 - cmd_per_lun isn't the untagged queue depth for many modern drivers
   that can handle multiple untagged commands, and this is the only
   place in the midlayer assuming that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/scsi.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 72282ae..6b0d524 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -820,12 +820,6 @@ int scsi_track_queue_full(struct scsi_device *sdev, int depth)
 
 	if (sdev->last_queue_full_count <= 10)
 		return 0;
-	if (sdev->last_queue_full_depth < 8) {
-		/* Drop back to untagged */
-		scsi_set_tag_type(sdev, 0);
-		scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun);
-		return -1;
-	}
 
 	return scsi_change_queue_depth(sdev, depth);
 }
-- 
1.9.1

[PATCH 3/4] scsi: remove scsi_get_tag_type

[Christoph Hellwig]

Both remaining users are better of just checking sdev->simple_tags
directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/53c700.c   |  4 ++--
 drivers/scsi/ipr.c      |  2 +-
 include/scsi/scsi_tcq.h | 13 -------------
 3 files changed, 3 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
index e722911..2c87a7a 100644
--- a/drivers/scsi/53c700.c
+++ b/drivers/scsi/53c700.c
@@ -1816,8 +1816,8 @@ NCR_700_queuecommand_lck(struct scsi_cmnd *SCp, void (*done)(struct scsi_cmnd *)
 		hostdata->tag_negotiated &= ~(1<<scmd_id(SCp));
 	}
 
-	if((hostdata->tag_negotiated &(1<<scmd_id(SCp)))
-	   && scsi_get_tag_type(SCp->device)) {
+	if ((hostdata->tag_negotiated & (1<<scmd_id(SCp))) &&
+	    SCp->device->simple_tags) {
 		slot->tag = SCp->request->tag;
 		CDEBUG(KERN_DEBUG, SCp, "sending out tag %d, slot %p\n",
 		       slot->tag, slot);
diff --git a/drivers/scsi/ipr.c b/drivers/scsi/ipr.c
index c35ef5f..c91c7c5 100644
--- a/drivers/scsi/ipr.c
+++ b/drivers/scsi/ipr.c
@@ -5755,7 +5755,7 @@ static void ipr_erp_cancel_all(struct ipr_cmnd *ipr_cmd)
 
 	ipr_reinit_ipr_cmnd_for_erp(ipr_cmd);
 
-	if (!scsi_get_tag_type(scsi_cmd->device)) {
+	if (!scsi_cmd->device->simple_tags) {
 		ipr_erp_request_sense(ipr_cmd);
 		return;
 	}
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index 59578be..681e010 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -15,19 +15,6 @@
 
 
 #ifdef CONFIG_BLOCK
-/**
- * scsi_get_tag_type - get the type of tag the device supports
- * @sdev:	the scsi device
- */
-static inline int scsi_get_tag_type(struct scsi_device *sdev)
-{
-	if (!sdev->tagged_supported)
-		return 0;
-	if (sdev->simple_tags)
-		return MSG_SIMPLE_TAG;
-	return 0;
-}
-
 static inline void scsi_set_tag_type(struct scsi_device *sdev, int tag)
 {
 	switch (tag) {
-- 
1.9.1

[PATCH 4/4] scsi: remove scsi_set_tag_type

[Christoph Hellwig]

There is no benefit over just setting sdev->simple_tags directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/53c700.c   |  2 +-
 drivers/scsi/tmscsim.c  |  2 +-
 include/scsi/scsi_tcq.h | 15 ---------------
 3 files changed, 2 insertions(+), 17 deletions(-)

diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
index 2c87a7a..82abfce 100644
--- a/drivers/scsi/53c700.c
+++ b/drivers/scsi/53c700.c
@@ -902,8 +902,8 @@ process_message(struct Scsi_Host *host,	struct NCR_700_Host_Parameters *hostdata
 			hostdata->tag_negotiated &= ~(1<<scmd_id(SCp));
 
 			SCp->device->tagged_supported = 0;
+			SCp->device->simple_tags = 0;
 			scsi_change_queue_depth(SCp->device, host->cmd_per_lun);
-			scsi_set_tag_type(SCp->device, 0);
 		} else {
 			shost_printk(KERN_WARNING, host,
 				"(%d:%d) Unexpected REJECT Message %s\n",
diff --git a/drivers/scsi/tmscsim.c b/drivers/scsi/tmscsim.c
index 6c3c2ce..14ccc9a 100644
--- a/drivers/scsi/tmscsim.c
+++ b/drivers/scsi/tmscsim.c
@@ -2190,7 +2190,7 @@ static int dc390_slave_configure(struct scsi_device *sdev)
 	 * XXX: Note that while this driver used to called scsi_activate_tcq,
 	 * it never actually set a tag type, so emulate the old behavior.
 	 */
-	scsi_set_tag_type(sdev, 0);
+	sdev->simple_tags = 0;
 
 	if (sdev->tagged_supported && (dcb->DevMode & TAG_QUEUEING_)) {
 		dcb->SyncMode |= EN_TAG_QUEUEING;
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index 681e010..e624aca 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -15,21 +15,6 @@
 
 
 #ifdef CONFIG_BLOCK
-static inline void scsi_set_tag_type(struct scsi_device *sdev, int tag)
-{
-	switch (tag) {
-	case MSG_ORDERED_TAG:
-	case MSG_SIMPLE_TAG:
-		sdev->simple_tags = 1;
-		break;
-	case 0:
-		/* fall through */
-	default:
-		sdev->simple_tags = 0;
-		break;
-	}
-}
-
 static inline struct scsi_cmnd *scsi_mq_find_tag(struct Scsi_Host *shost,
 						 int unique_tag)
 {
-- 
1.9.1

[PATCH 5/4] scsi: remove MSG_*_TAG defines

[Christoph Hellwig]

For SPI drivers use the message defintions from scsi.c, and for target
drivers introduce a new TCM_*_TAG namespace.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/infiniband/ulp/srpt/ib_srpt.c      | 10 +++++-----
 drivers/scsi/advansys.c                    |  8 ++++----
 drivers/scsi/qla2xxx/qla_target.c          | 12 ++++++------
 drivers/scsi/scsi_debug.c                  |  1 -
 drivers/scsi/scsi_transport_spi.c          |  2 +-
 drivers/scsi/tmscsim.c                     |  2 +-
 drivers/target/iscsi/iscsi_target.c        | 14 +++++++-------
 drivers/target/loopback/tcm_loop.c         |  4 ++--
 drivers/target/sbp/sbp_target.c            |  2 +-
 drivers/target/target_core_pscsi.c         |  2 +-
 drivers/target/target_core_sbc.c           |  2 +-
 drivers/target/target_core_spc.c           |  4 ++--
 drivers/target/target_core_transport.c     | 16 ++++++++--------
 drivers/target/tcm_fc/tfc_cmd.c            |  8 ++++----
 drivers/usb/gadget/legacy/tcm_usb_gadget.c | 10 +++++-----
 drivers/xen/xen-scsiback.c                 |  2 +-
 include/scsi/scsi_tcq.h                    |  5 -----
 include/target/target_core_base.h          |  6 ++++++
 include/trace/events/target.h              |  8 ++++----
 19 files changed, 59 insertions(+), 59 deletions(-)

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 7206547..3a0ca61 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -1708,17 +1708,17 @@ static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
 
 	switch (srp_cmd->task_attr) {
 	case SRP_CMD_SIMPLE_Q:
-		cmd->sam_task_attr = MSG_SIMPLE_TAG;
+		cmd->sam_task_attr = TCM_SIMPLE_TAG;
 		break;
 	case SRP_CMD_ORDERED_Q:
 	default:
-		cmd->sam_task_attr = MSG_ORDERED_TAG;
+		cmd->sam_task_attr = TCM_ORDERED_TAG;
 		break;
 	case SRP_CMD_HEAD_OF_Q:
-		cmd->sam_task_attr = MSG_HEAD_TAG;
+		cmd->sam_task_attr = TCM_HEAD_TAG;
 		break;
 	case SRP_CMD_ACA:
-		cmd->sam_task_attr = MSG_ACA_TAG;
+		cmd->sam_task_attr = TCM_ACA_TAG;
 		break;
 	}
 
@@ -1733,7 +1733,7 @@ static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
 				       sizeof(srp_cmd->lun));
 	rc = target_submit_cmd(cmd, ch->sess, srp_cmd->cdb,
 			&send_ioctx->sense_data[0], unpacked_lun, data_len,
-			MSG_SIMPLE_TAG, dir, TARGET_SCF_ACK_KREF);
+			TCM_SIMPLE_TAG, dir, TARGET_SCF_ACK_KREF);
 	if (rc != 0) {
 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 		goto send_sense;
diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
index 6719a33..2c5ce48 100644
--- a/drivers/scsi/advansys.c
+++ b/drivers/scsi/advansys.c
@@ -7921,9 +7921,9 @@ static int asc_build_req(struct asc_board *boardp, struct scsi_cmnd *scp,
 	 */
 	if ((asc_dvc->cur_dvc_qng[scp->device->id] > 0) &&
 	    (boardp->reqcnt[scp->device->id] % 255) == 0) {
-		asc_scsi_q->q2.tag_code = MSG_ORDERED_TAG;
+		asc_scsi_q->q2.tag_code = ORDERED_QUEUE_TAG;
 	} else {
-		asc_scsi_q->q2.tag_code = MSG_SIMPLE_TAG;
+		asc_scsi_q->q2.tag_code = SIMPLE_QUEUE_TAG;
 	}
 
 	/* Build ASC_SCSI_Q */
@@ -8351,7 +8351,7 @@ static int AscPutReadyQueue(ASC_DVC_VAR *asc_dvc, ASC_SCSI_Q *scsiq, uchar q_no)
 	}
 	q_addr = ASC_QNO_TO_QADDR(q_no);
 	if ((scsiq->q1.target_id & asc_dvc->use_tagged_qng) == 0) {
-		scsiq->q2.tag_code &= ~MSG_SIMPLE_TAG;
+		scsiq->q2.tag_code &= ~SIMPLE_QUEUE_TAG;
 	}
 	scsiq->q1.status = QS_FREE;
 	AscMemWordCopyPtrToLram(iop_base,
@@ -8669,7 +8669,7 @@ static int AscExeScsiQueue(ASC_DVC_VAR *asc_dvc, ASC_SCSI_Q *scsiq)
 		}
 	}
 	if (disable_syn_offset_one_fix) {
-		scsiq->q2.tag_code &= ~MSG_SIMPLE_TAG;
+		scsiq->q2.tag_code &= ~SIMPLE_QUEUE_TAG;
 		scsiq->q2.tag_code |= (ASC_TAG_FLAG_DISABLE_ASYN_USE_SYN_FIX |
 				       ASC_TAG_FLAG_DISABLE_DISCONNECT);
 	} else {
diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index a902fa1..5741825 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -3218,25 +3218,25 @@ static inline int qlt_get_fcp_task_attr(struct scsi_qla_host *vha,
 
 	switch (task_codes) {
 	case ATIO_SIMPLE_QUEUE:
-		fcp_task_attr = MSG_SIMPLE_TAG;
+		fcp_task_attr = TCM_SIMPLE_TAG;
 		break;
 	case ATIO_HEAD_OF_QUEUE:
-		fcp_task_attr = MSG_HEAD_TAG;
+		fcp_task_attr = TCM_HEAD_TAG;
 		break;
 	case ATIO_ORDERED_QUEUE:
-		fcp_task_attr = MSG_ORDERED_TAG;
+		fcp_task_attr = TCM_ORDERED_TAG;
 		break;
 	case ATIO_ACA_QUEUE:
-		fcp_task_attr = MSG_ACA_TAG;
+		fcp_task_attr = TCM_ACA_TAG;
 		break;
 	case ATIO_UNTAGGED:
-		fcp_task_attr = MSG_SIMPLE_TAG;
+		fcp_task_attr = TCM_SIMPLE_TAG;
 		break;
 	default:
 		ql_dbg(ql_dbg_tgt_mgt, vha, 0xf05d,
 		    "qla_target: unknown task code %x, use ORDERED instead\n",
 		    task_codes);
-		fcp_task_attr = MSG_ORDERED_TAG;
+		fcp_task_attr = TCM_ORDERED_TAG;
 		break;
 	}
 
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 169c84f..bac3e62 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -125,7 +125,6 @@ static const char *scsi_debug_version_date = "20140706";
 #define DEF_REMOVABLE false
 #define DEF_SCSI_LEVEL   6    /* INQUIRY, byte2 [6->SPC-4] */
 #define DEF_SECTOR_SIZE 512
-#define DEF_TAGGED_QUEUING 0 /* 0 | MSG_SIMPLE_TAG | MSG_ORDERED_TAG */
 #define DEF_UNMAP_ALIGNMENT 0
 #define DEF_UNMAP_GRANULARITY 1
 #define DEF_UNMAP_MAX_BLOCKS 0xFFFFFFFF
diff --git a/drivers/scsi/scsi_transport_spi.c b/drivers/scsi/scsi_transport_spi.c
index fa2aece..31bbb0d 100644
--- a/drivers/scsi/scsi_transport_spi.c
+++ b/drivers/scsi/scsi_transport_spi.c
@@ -1221,7 +1221,7 @@ EXPORT_SYMBOL_GPL(spi_populate_ppr_msg);
 int spi_populate_tag_msg(unsigned char *msg, struct scsi_cmnd *cmd)
 {
         if (cmd->flags & SCMD_TAGGED) {
-		*msg++ = MSG_SIMPLE_TAG;
+		*msg++ = SIMPLE_QUEUE_TAG;
         	*msg++ = cmd->request->tag;
         	return 2;
 	}
diff --git a/drivers/scsi/tmscsim.c b/drivers/scsi/tmscsim.c
index 14ccc9a..bdfbc27 100644
--- a/drivers/scsi/tmscsim.c
+++ b/drivers/scsi/tmscsim.c
@@ -559,7 +559,7 @@ dc390_StartSCSI( struct dc390_acb* pACB, struct dc390_dcb* pDCB, struct dc390_sr
     DC390_write8 (ScsiFifo, IDENTIFY(disc_allowed, pDCB->TargetLUN));
     /* Change 99/05/31: Don't use tags when not disconnecting (BUSY) */
     if ((pDCB->SyncMode & EN_TAG_QUEUEING) && disc_allowed && (scmd->flags & SCMD_TAGGED)) {
-	DC390_write8(ScsiFifo, MSG_SIMPLE_TAG);
+	DC390_write8(ScsiFifo, SIMPLE_QUEUE_TAG);
 	pDCB->TagMask |= 1 << scmd->request->tag;
 	pSRB->TagNumber = scmd->request->tag;
 	DC390_write8(ScsiFifo, scmd->request->tag);
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index b19e432..67802cc 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -943,17 +943,17 @@ int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
 	 */
 	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
 	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
-		sam_task_attr = MSG_SIMPLE_TAG;
+		sam_task_attr = TCM_SIMPLE_TAG;
 	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
-		sam_task_attr = MSG_ORDERED_TAG;
+		sam_task_attr = TCM_ORDERED_TAG;
 	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
-		sam_task_attr = MSG_HEAD_TAG;
+		sam_task_attr = TCM_HEAD_TAG;
 	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
-		sam_task_attr = MSG_ACA_TAG;
+		sam_task_attr = TCM_ACA_TAG;
 	else {
 		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
-			" MSG_SIMPLE_TAG\n", iscsi_task_attr);
-		sam_task_attr = MSG_SIMPLE_TAG;
+			" TCM_SIMPLE_TAG\n", iscsi_task_attr);
+		sam_task_attr = TCM_SIMPLE_TAG;
 	}
 
 	cmd->iscsi_opcode	= ISCSI_OP_SCSI_CMD;
@@ -1811,7 +1811,7 @@ iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
 		transport_init_se_cmd(&cmd->se_cmd,
 				      &lio_target_fabric_configfs->tf_ops,
 				      conn->sess->se_sess, 0, DMA_NONE,
-				      MSG_SIMPLE_TAG, cmd->sense_buffer + 2);
+				      TCM_SIMPLE_TAG, cmd->sense_buffer + 2);
 
 		target_get_sess_cmd(conn->sess->se_sess, &cmd->se_cmd, true);
 		sess_ref = true;
diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 24e2c94..dda9a08 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -168,7 +168,7 @@ static void tcm_loop_submission_work(struct work_struct *work)
 
 	rc = target_submit_cmd_map_sgls(se_cmd, tl_nexus->se_sess, sc->cmnd,
 			&tl_cmd->tl_sense_buf[0], tl_cmd->sc->device->lun,
-			transfer_length, MSG_SIMPLE_TAG,
+			transfer_length, TCM_SIMPLE_TAG,
 			sc->sc_data_direction, 0,
 			scsi_sglist(sc), scsi_sg_count(sc),
 			sgl_bidi, sgl_bidi_count,
@@ -248,7 +248,7 @@ static int tcm_loop_issue_tmr(struct tcm_loop_tpg *tl_tpg,
 	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
 	 */
 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, 0,
-				DMA_NONE, MSG_SIMPLE_TAG,
+				DMA_NONE, TCM_SIMPLE_TAG,
 				&tl_cmd->tl_sense_buf[0]);
 
 	rc = core_tmr_alloc_req(se_cmd, tl_tmr, tmr, GFP_KERNEL);
diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c
index e7e9372..9512af6 100644
--- a/drivers/target/sbp/sbp_target.c
+++ b/drivers/target/sbp/sbp_target.c
@@ -1237,7 +1237,7 @@ static void sbp_handle_command(struct sbp_target_request *req)
 
 	if (target_submit_cmd(&req->se_cmd, sess->se_sess, req->cmd_buf,
 			      req->sense_buf, unpacked_lun, data_length,
-			      MSG_SIMPLE_TAG, data_dir, 0))
+			      TCM_SIMPLE_TAG, data_dir, 0))
 		goto err;
 
 	return;
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index 7c8291f..caf03d5 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -1094,7 +1094,7 @@ pscsi_execute_cmd(struct se_cmd *cmd)
 	req->retries = PS_RETRY;
 
 	blk_execute_rq_nowait(pdv->pdv_sd->request_queue, NULL, req,
-			(cmd->sam_task_attr == MSG_HEAD_TAG),
+			(cmd->sam_task_attr == TCM_HEAD_TAG),
 			pscsi_req_done);
 
 	return 0;
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index ebe62af..d6e06af 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -485,7 +485,7 @@ static sense_reason_t compare_and_write_callback(struct se_cmd *cmd)
 	cmd->t_data_nents_orig = cmd->t_data_nents;
 	cmd->t_data_nents = 1;
 
-	cmd->sam_task_attr = MSG_HEAD_TAG;
+	cmd->sam_task_attr = TCM_HEAD_TAG;
 	cmd->transport_complete_callback = compare_and_write_post;
 	/*
 	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
diff --git a/drivers/target/target_core_spc.c b/drivers/target/target_core_spc.c
index bc286a6..1307600 100644
--- a/drivers/target/target_core_spc.c
+++ b/drivers/target/target_core_spc.c
@@ -1357,7 +1357,7 @@ spc_parse_cdb(struct se_cmd *cmd, unsigned int *size)
 		 * Do implicit HEAD_OF_QUEUE processing for INQUIRY.
 		 * See spc4r17 section 5.3
 		 */
-		cmd->sam_task_attr = MSG_HEAD_TAG;
+		cmd->sam_task_attr = TCM_HEAD_TAG;
 		cmd->execute_cmd = spc_emulate_inquiry;
 		break;
 	case SECURITY_PROTOCOL_IN:
@@ -1391,7 +1391,7 @@ spc_parse_cdb(struct se_cmd *cmd, unsigned int *size)
 		 * Do implicit HEAD_OF_QUEUE processing for REPORT_LUNS
 		 * See spc4r17 section 5.3
 		 */
-		cmd->sam_task_attr = MSG_HEAD_TAG;
+		cmd->sam_task_attr = TCM_HEAD_TAG;
 		break;
 	case TEST_UNIT_READY:
 		cmd->execute_cmd = spc_emulate_testunitready;
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 9ea0d5f..d9b5010 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1159,7 +1159,7 @@ transport_check_alloc_task_attr(struct se_cmd *cmd)
 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
 		return 0;
 
-	if (cmd->sam_task_attr == MSG_ACA_TAG) {
+	if (cmd->sam_task_attr == TCM_ACA_TAG) {
 		pr_debug("SAM Task Attribute ACA"
 			" emulation is not supported\n");
 		return TCM_INVALID_CDB_FIELD;
@@ -1531,7 +1531,7 @@ int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
 	BUG_ON(!se_tpg);
 
 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
-			      0, DMA_NONE, MSG_SIMPLE_TAG, sense);
+			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
 	/*
 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
 	 * allocation failure.
@@ -1718,12 +1718,12 @@ static bool target_handle_task_attr(struct se_cmd *cmd)
 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
 	 */
 	switch (cmd->sam_task_attr) {
-	case MSG_HEAD_TAG:
+	case TCM_HEAD_TAG:
 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
 			 "se_ordered_id: %u\n",
 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
 		return false;
-	case MSG_ORDERED_TAG:
+	case TCM_ORDERED_TAG:
 		atomic_inc_mb(&dev->dev_ordered_sync);
 
 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
@@ -1828,7 +1828,7 @@ static void target_restart_delayed_cmds(struct se_device *dev)
 
 		__target_execute_cmd(cmd);
 
-		if (cmd->sam_task_attr == MSG_ORDERED_TAG)
+		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
 			break;
 	}
 }
@@ -1844,18 +1844,18 @@ static void transport_complete_task_attr(struct se_cmd *cmd)
 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
 		return;
 
-	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
+	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
 		atomic_dec_mb(&dev->simple_cmds);
 		dev->dev_cur_ordered_id++;
 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
 			cmd->se_ordered_id);
-	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
+	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
 		dev->dev_cur_ordered_id++;
 		pr_debug("Incremented dev_cur_ordered_id: %u for"
 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
 			cmd->se_ordered_id);
-	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
+	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
 		atomic_dec_mb(&dev->dev_ordered_sync);
 
 		dev->dev_cur_ordered_id++;
diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index be0c0d0..edcafa4 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -554,17 +554,17 @@ static void ft_send_work(struct work_struct *work)
 	 */
 	switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
 	case FCP_PTA_HEADQ:
-		task_attr = MSG_HEAD_TAG;
+		task_attr = TCM_HEAD_TAG;
 		break;
 	case FCP_PTA_ORDERED:
-		task_attr = MSG_ORDERED_TAG;
+		task_attr = TCM_ORDERED_TAG;
 		break;
 	case FCP_PTA_ACA:
-		task_attr = MSG_ACA_TAG;
+		task_attr = TCM_ACA_TAG;
 		break;
 	case FCP_PTA_SIMPLE: /* Fallthrough */
 	default:
-		task_attr = MSG_SIMPLE_TAG;
+		task_attr = TCM_SIMPLE_TAG;
 	}
 
 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
diff --git a/drivers/usb/gadget/legacy/tcm_usb_gadget.c b/drivers/usb/gadget/legacy/tcm_usb_gadget.c
index 6cdb7a5..283ee14 100644
--- a/drivers/usb/gadget/legacy/tcm_usb_gadget.c
+++ b/drivers/usb/gadget/legacy/tcm_usb_gadget.c
@@ -1131,19 +1131,19 @@ static int usbg_submit_command(struct f_uas *fu,
 
 	switch (cmd_iu->prio_attr & 0x7) {
 	case UAS_HEAD_TAG:
-		cmd->prio_attr = MSG_HEAD_TAG;
+		cmd->prio_attr = TCM_HEAD_TAG;
 		break;
 	case UAS_ORDERED_TAG:
-		cmd->prio_attr = MSG_ORDERED_TAG;
+		cmd->prio_attr = TCM_ORDERED_TAG;
 		break;
 	case UAS_ACA:
-		cmd->prio_attr = MSG_ACA_TAG;
+		cmd->prio_attr = TCM_ACA_TAG;
 		break;
 	default:
 		pr_debug_once("Unsupported prio_attr: %02x.\n",
 				cmd_iu->prio_attr);
 	case UAS_SIMPLE_TAG:
-		cmd->prio_attr = MSG_SIMPLE_TAG;
+		cmd->prio_attr = TCM_SIMPLE_TAG;
 		break;
 	}
 
@@ -1240,7 +1240,7 @@ static int bot_submit_command(struct f_uas *fu,
 		goto err;
 	}
 
-	cmd->prio_attr = MSG_SIMPLE_TAG;
+	cmd->prio_attr = TCM_SIMPLE_TAG;
 	se_cmd = &cmd->se_cmd;
 	cmd->unpacked_lun = cbw->Lun;
 	cmd->is_read = cbw->Flags & US_BULK_FLAG_IN ? 1 : 0;
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 50610a6..e999496e 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -606,7 +606,7 @@ static void scsiback_device_action(struct vscsibk_pend *pending_req,
 	init_waitqueue_head(&tmr->tmr_wait);
 
 	transport_init_se_cmd(se_cmd, tpg->se_tpg.se_tpg_tfo,
-		tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, MSG_SIMPLE_TAG,
+		tpg->tpg_nexus->tvn_se_sess, 0, DMA_NONE, TCM_SIMPLE_TAG,
 		&pending_req->sense_buffer[0]);
 
 	rc = core_tmr_alloc_req(se_cmd, tmr, act, GFP_KERNEL);
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index e624aca..9708b28 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -6,11 +6,6 @@
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
 
-#define MSG_SIMPLE_TAG	0x20
-#define MSG_HEAD_TAG	0x21
-#define MSG_ORDERED_TAG	0x22
-#define MSG_ACA_TAG	0x24	/* unsupported */
-
 #define SCSI_NO_TAG	(-1)    /* identify no tag in use */
 
 
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 23c518a..397fb63 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -476,6 +476,12 @@ struct se_dif_v1_tuple {
 	__be32			ref_tag;
 };
 
+/* for sam_task_attr */
+#define TCM_SIMPLE_TAG	0x20
+#define TCM_HEAD_TAG	0x21
+#define TCM_ORDERED_TAG	0x22
+#define TCM_ACA_TAG	0x24
+
 struct se_cmd {
 	/* SAM response code being sent to initiator */
 	u8			scsi_status;
diff --git a/include/trace/events/target.h b/include/trace/events/target.h
index da9cc0f..a456680 100644
--- a/include/trace/events/target.h
+++ b/include/trace/events/target.h
@@ -109,10 +109,10 @@
 
 #define show_task_attribute_name(val)				\
 	__print_symbolic(val,					\
-		{ MSG_SIMPLE_TAG,	"SIMPLE"	},	\
-		{ MSG_HEAD_TAG,		"HEAD"		},	\
-		{ MSG_ORDERED_TAG,	"ORDERED"	},	\
-		{ MSG_ACA_TAG,		"ACA"		} )
+		{ TCM_SIMPLE_TAG,	"SIMPLE"	},	\
+		{ TCM_HEAD_TAG,		"HEAD"		},	\
+		{ TCM_ORDERED_TAG,	"ORDERED"	},	\
+		{ TCM_ACA_TAG,		"ACA"		} )
 
 #define show_scsi_status_name(val)				\
 	__print_symbolic(val,					\
-- 
1.9.1

Re: [PATCH 5/4] scsi: remove MSG_*_TAG defines

[Bart Van Assche]

On 11/24/14 16:07, Christoph Hellwig wrote:
> index 6719a33..2c5ce48 100644
> --- a/drivers/scsi/advansys.c
> +++ b/drivers/scsi/advansys.c
> @@ -7921,9 +7921,9 @@ static int asc_build_req(struct asc_board *boardp, struct scsi_cmnd *scp,
>   	 */
>   	if ((asc_dvc->cur_dvc_qng[scp->device->id] > 0) &&
>   	    (boardp->reqcnt[scp->device->id] % 255) == 0) {
> -		asc_scsi_q->q2.tag_code = MSG_ORDERED_TAG;
> +		asc_scsi_q->q2.tag_code = ORDERED_QUEUE_TAG;
>   	} else {
> -		asc_scsi_q->q2.tag_code = MSG_SIMPLE_TAG;
> +		asc_scsi_q->q2.tag_code = SIMPLE_QUEUE_TAG;
>   	}
>
>   	/* Build ASC_SCSI_Q */
> @@ -8351,7 +8351,7 @@ static int AscPutReadyQueue(ASC_DVC_VAR *asc_dvc, ASC_SCSI_Q *scsiq, uchar q_no)
>   	}
>   	q_addr = ASC_QNO_TO_QADDR(q_no);
>   	if ((scsiq->q1.target_id & asc_dvc->use_tagged_qng) == 0) {
> -		scsiq->q2.tag_code &= ~MSG_SIMPLE_TAG;
> +		scsiq->q2.tag_code &= ~SIMPLE_QUEUE_TAG;
>   	}
>   	scsiq->q1.status = QS_FREE;
>   	AscMemWordCopyPtrToLram(iop_base,
> @@ -8669,7 +8669,7 @@ static int AscExeScsiQueue(ASC_DVC_VAR *asc_dvc, ASC_SCSI_Q *scsiq)
>   		}
>   	}
>   	if (disable_syn_offset_one_fix) {
> -		scsiq->q2.tag_code &= ~MSG_SIMPLE_TAG;
> +		scsiq->q2.tag_code &= ~SIMPLE_QUEUE_TAG;
>   		scsiq->q2.tag_code |= (ASC_TAG_FLAG_DISABLE_ASYN_USE_SYN_FIX |
>   				       ASC_TAG_FLAG_DISABLE_DISCONNECT);
>   	} else {

One of the statements in advansys.c (tag_code &= 0xDC) makes assumptions 
about the numeric value of MSG_SIMPLE_TAG. This makes me wonder whether 
it is safe to change MSG_SIMPLE_TAG into another value ?

Bart.

Re: [PATCH 1/4] scsi: remove ->change_queue_type method

[Bart Van Assche]

On 11/24/14 15:36, Christoph Hellwig wrote:
> Since we got rid of ordered tag support in 2010 the prime use case of
> switching on and off ordered tags has been obsolete.  The other function
> of enabling/dsiabling tagging entirely has only been correctly implemented
> by the 53c700 driver and isn't generally useful.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH 2/4] scsi: never drop to untagged mode during queue ramp down

[Bart Van Assche]

On 11/24/14 15:36, Christoph Hellwig wrote:
> Dropping to untagged mode when ramping down a queue due to QUEUE FULL
> events has two problems:
>
>   - nothing in the midlayer or drivers ever moves back to tagged mode
>     during queue ramp up.
>   - cmd_per_lun isn't the untagged queue depth for many modern drivers
>     that can handle multiple untagged commands, and this is the only
>     place in the midlayer assuming that.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH 3/4] scsi: remove scsi_get_tag_type

[Bart Van Assche]

On 11/24/14 15:36, Christoph Hellwig wrote:
> Both remaining users are better of just checking sdev->simple_tags
> directly.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH 4/4] scsi: remove scsi_set_tag_type

[Bart Van Assche]

On 11/24/14 15:36, Christoph Hellwig wrote:
> There is no benefit over just setting sdev->simple_tags directly.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH 5/4] scsi: remove MSG_*_TAG defines

[Christoph Hellwig]

On Fri, Nov 28, 2014 at 10:58:58AM +0100, Bart Van Assche wrote:
> >  	if (disable_syn_offset_one_fix) {
> >-		scsiq->q2.tag_code &= ~MSG_SIMPLE_TAG;
> >+		scsiq->q2.tag_code &= ~SIMPLE_QUEUE_TAG;
> >  		scsiq->q2.tag_code |= (ASC_TAG_FLAG_DISABLE_ASYN_USE_SYN_FIX |
> >  				       ASC_TAG_FLAG_DISABLE_DISCONNECT);
> >  	} else {
> 
> One of the statements in advansys.c (tag_code &= 0xDC) makes assumptions
> about the numeric value of MSG_SIMPLE_TAG. This makes me wonder whether it
> is safe to change MSG_SIMPLE_TAG into another value ?

MSG_SIMPLE_TAG and SIMPLE_QUEUE_TAG are two different symbolic names
for the 0x20 value assigned to the SCSI-2 protocol "SIMPLE QUEUE TAG"
message.  Having both is confusing, so I decided to only keep the one
that is named closer to the spec, and in the same namespace as the
symbolic names we use for other SCSI-2 messages.

Re: [PATCH 5/4] scsi: remove MSG_*_TAG defines

[Bart Van Assche]

On 12/01/14 10:03, Christoph Hellwig wrote:
> On Fri, Nov 28, 2014 at 10:58:58AM +0100, Bart Van Assche wrote:
>>>   	if (disable_syn_offset_one_fix) {
>>> -		scsiq->q2.tag_code &= ~MSG_SIMPLE_TAG;
>>> +		scsiq->q2.tag_code &= ~SIMPLE_QUEUE_TAG;
>>>   		scsiq->q2.tag_code |= (ASC_TAG_FLAG_DISABLE_ASYN_USE_SYN_FIX |
>>>   				       ASC_TAG_FLAG_DISABLE_DISCONNECT);
>>>   	} else {
>>
>> One of the statements in advansys.c (tag_code &= 0xDC) makes assumptions
>> about the numeric value of MSG_SIMPLE_TAG. This makes me wonder whether it
>> is safe to change MSG_SIMPLE_TAG into another value ?
>
> MSG_SIMPLE_TAG and SIMPLE_QUEUE_TAG are two different symbolic names
> for the 0x20 value assigned to the SCSI-2 protocol "SIMPLE QUEUE TAG"
> message.  Having both is confusing, so I decided to only keep the one
> that is named closer to the spec, and in the same namespace as the
> symbolic names we use for other SCSI-2 messages.

Thanks for the clarification. Using different namespaces for symbolic 
constants for initiator and target drivers definitely looks like a good 
idea to me. The patch itself also looks fine to me. Hence:

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: queue_type fixups

[Christoph Hellwig]

Any chance to get another review for these to complete the queue depth /
type changes for this merge window?

On Mon, Nov 24, 2014 at 03:36:17PM +0100, Christoph Hellwig wrote:
> These are a few patches that follow up my previous cleanups for the
> queue depth and type handling.
> 
> The first patch removes the now pointless write support for the queue_type
> sysfs attribute.  The second changes the queue full tracking code to
> never drop out of tagged mode, as we can't recover from that, and the
> last two are random cleanups.
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
---end quoted text---

Re: [PATCH 1/4] scsi: remove ->change_queue_type method

[Hannes Reinecke]

On 11/24/2014 03:36 PM, Christoph Hellwig wrote:
> Since we got rid of ordered tag support in 2010 the prime use case of
> switching on and off ordered tags has been obsolete.  The other function
> of enabling/dsiabling tagging entirely has only been correctly implemented
> by the 53c700 driver and isn't generally useful.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/infiniband/ulp/srp/ib_srp.c  |  1 -
>  drivers/scsi/53c700.c                | 35 -----------------------------------
>  drivers/scsi/aic94xx/aic94xx_init.c  |  1 -
>  drivers/scsi/bnx2fc/bnx2fc_fcoe.c    |  1 -
>  drivers/scsi/esas2r/esas2r_main.c    |  1 -
>  drivers/scsi/fcoe/fcoe.c             |  1 -
>  drivers/scsi/fnic/fnic_main.c        |  1 -
>  drivers/scsi/ibmvscsi/ibmvfc.c       |  1 -
>  drivers/scsi/ipr.c                   | 25 -------------------------
>  drivers/scsi/isci/init.c             |  1 -
>  drivers/scsi/libsas/sas_scsi_host.c  |  8 --------
>  drivers/scsi/lpfc/lpfc_scsi.c        |  2 --
>  drivers/scsi/mpt2sas/mpt2sas_scsih.c |  1 -
>  drivers/scsi/mpt3sas/mpt3sas_scsih.c |  1 -
>  drivers/scsi/mvsas/mv_init.c         |  1 -
>  drivers/scsi/pm8001/pm8001_init.c    |  1 -
>  drivers/scsi/pmcraid.c               |  1 -
>  drivers/scsi/qla2xxx/qla_os.c        |  1 -
>  drivers/scsi/scsi.c                  | 16 ----------------
>  drivers/scsi/scsi_debug.c            | 27 ---------------------------
>  drivers/scsi/scsi_sysfs.c            | 30 ++++--------------------------
>  drivers/target/loopback/tcm_loop.c   |  1 -
>  include/scsi/libsas.h                |  1 -
>  include/scsi/scsi_host.h             | 13 -------------
>  include/scsi/scsi_tcq.h              |  3 ---
>  25 files changed, 4 insertions(+), 171 deletions(-)
> 

[ .. ]

> diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
> index 1cb64a8..1ac38e7 100644
> --- a/drivers/scsi/scsi_sysfs.c
> +++ b/drivers/scsi/scsi_sysfs.c
> @@ -738,30 +738,12 @@ store_queue_type_field(struct device *dev, struct device_attribute *attr,
>  		       const char *buf, size_t count)
>  {
>  	struct scsi_device *sdev = to_scsi_device(dev);
> -	struct scsi_host_template *sht = sdev->host->hostt;
> -	int tag_type = 0, retval;
> -	int prev_tag_type = scsi_get_tag_type(sdev);
> -
> -	if (!sdev->tagged_supported || !sht->change_queue_type)
> -		return -EINVAL;
>  
> -	/*
> -	 * We're never issueing order tags these days, but allow the value
> -	 * for backwards compatibility.
> -	 */
> -	if (strncmp(buf, "ordered", 7) == 0 ||
> -	    strncmp(buf, "simple", 6) == 0)
> -		tag_type = MSG_SIMPLE_TAG;
> -	else if (strncmp(buf, "none", 4) != 0)
> +	if (!sdev->tagged_supported)
>  		return -EINVAL;
> -
> -	if (tag_type == prev_tag_type)
> -		return count;
> -
> -	retval = sht->change_queue_type(sdev, tag_type);
> -	if (retval < 0)
> -		return retval;
> -
> +		
> +	sdev_printk(KERN_INFO, sdev,
> +		    "ignoring write to deprecated queue_type attribute");
>  	return count;
>  }
>  
> @@ -938,10 +920,6 @@ static umode_t scsi_sdev_attr_is_visible(struct kobject *kobj,
>  	    !sdev->host->hostt->change_queue_depth)
>  		return 0;
>  
> -	if (attr == &dev_attr_queue_type.attr &&
> -	    !sdev->host->hostt->change_queue_type)
> -		return S_IRUGO;
> -
>  	return attr->mode;
>  }
>  
Why not setting the attribute to S_IRUGO always and drop the 'store'
method altogether?

Otherwise:

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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Re: [PATCH 2/4] scsi: never drop to untagged mode during queue ramp down

[Hannes Reinecke]

On 11/24/2014 03:36 PM, Christoph Hellwig wrote:
> Dropping to untagged mode when ramping down a queue due to QUEUE FULL
> events has two problems:
> 
>  - nothing in the midlayer or drivers ever moves back to tagged mode
>    during queue ramp up.
>  - cmd_per_lun isn't the untagged queue depth for many modern drivers
>    that can handle multiple untagged commands, and this is the only
>    place in the midlayer assuming that.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/scsi/scsi.c | 6 ------
>  1 file changed, 6 deletions(-)
> 
> diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
> index 72282ae..6b0d524 100644
> --- a/drivers/scsi/scsi.c
> +++ b/drivers/scsi/scsi.c
> @@ -820,12 +820,6 @@ int scsi_track_queue_full(struct scsi_device *sdev, int depth)
>  
>  	if (sdev->last_queue_full_count <= 10)
>  		return 0;
> -	if (sdev->last_queue_full_depth < 8) {
> -		/* Drop back to untagged */
> -		scsi_set_tag_type(sdev, 0);
> -		scsi_change_queue_depth(sdev, sdev->host->cmd_per_lun);
> -		return -1;
> -	}
>  
>  	return scsi_change_queue_depth(sdev, depth);
>  }
> 
Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 21284 (AG Nürnberg)
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Re: [PATCH 3/4] scsi: remove scsi_get_tag_type

[Hannes Reinecke]

On 11/24/2014 03:36 PM, Christoph Hellwig wrote:
> Both remaining users are better of just checking sdev->simple_tags
> directly.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 21284 (AG Nürnberg)
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Re: [PATCH 4/4] scsi: remove scsi_set_tag_type

[Hannes Reinecke]

On 11/24/2014 03:36 PM, Christoph Hellwig wrote:
> There is no benefit over just setting sdev->simple_tags directly.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  drivers/scsi/53c700.c   |  2 +-
>  drivers/scsi/tmscsim.c  |  2 +-
>  include/scsi/scsi_tcq.h | 15 ---------------
>  3 files changed, 2 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/scsi/53c700.c b/drivers/scsi/53c700.c
> index 2c87a7a..82abfce 100644
> --- a/drivers/scsi/53c700.c
> +++ b/drivers/scsi/53c700.c
> @@ -902,8 +902,8 @@ process_message(struct Scsi_Host *host,	struct NCR_700_Host_Parameters *hostdata
>  			hostdata->tag_negotiated &= ~(1<<scmd_id(SCp));
>  
>  			SCp->device->tagged_supported = 0;
> +			SCp->device->simple_tags = 0;
>  			scsi_change_queue_depth(SCp->device, host->cmd_per_lun);
> -			scsi_set_tag_type(SCp->device, 0);
>  		} else {
>  			shost_printk(KERN_WARNING, host,
>  				"(%d:%d) Unexpected REJECT Message %s\n",
> diff --git a/drivers/scsi/tmscsim.c b/drivers/scsi/tmscsim.c
> index 6c3c2ce..14ccc9a 100644
> --- a/drivers/scsi/tmscsim.c
> +++ b/drivers/scsi/tmscsim.c
> @@ -2190,7 +2190,7 @@ static int dc390_slave_configure(struct scsi_device *sdev)
>  	 * XXX: Note that while this driver used to called scsi_activate_tcq,
>  	 * it never actually set a tag type, so emulate the old behavior.
>  	 */
> -	scsi_set_tag_type(sdev, 0);
> +	sdev->simple_tags = 0;
>  
>  	if (sdev->tagged_supported && (dcb->DevMode & TAG_QUEUEING_)) {
>  		dcb->SyncMode |= EN_TAG_QUEUEING;
> diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
> index 681e010..e624aca 100644
> --- a/include/scsi/scsi_tcq.h
> +++ b/include/scsi/scsi_tcq.h
> @@ -15,21 +15,6 @@
>  
>  
>  #ifdef CONFIG_BLOCK
> -static inline void scsi_set_tag_type(struct scsi_device *sdev, int tag)
> -{
> -	switch (tag) {
> -	case MSG_ORDERED_TAG:
> -	case MSG_SIMPLE_TAG:
> -		sdev->simple_tags = 1;
> -		break;
> -	case 0:
> -		/* fall through */
> -	default:
> -		sdev->simple_tags = 0;
> -		break;
> -	}
> -}
> -
>  static inline struct scsi_cmnd *scsi_mq_find_tag(struct Scsi_Host *shost,
>  						 int unique_tag)
>  {
> 
Probably needs to be adjusted now that's tmscsim is gone, but
nevertheless:

Reviewed-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 21284 (AG Nürnberg)
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Re: [PATCH 1/4] scsi: remove ->change_queue_type method

[Martin K. Petersen]

>>>>> "Christoph" == Christoph Hellwig <hch@lst.de> writes:

Christoph> Since we got rid of ordered tag support in 2010 the prime use
Christoph> case of switching on and off ordered tags has been obsolete.
Christoph> The other function of enabling/dsiabling tagging entirely has
Christoph> only been correctly implemented by the 53c700 driver and
Christoph> isn't generally useful.

s/dsiabling/disabling/

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 2/4] scsi: never drop to untagged mode during queue ramp down

[Martin K. Petersen]

>>>>> "Christoph" == Christoph Hellwig <hch@lst.de> writes:

Christoph> Dropping to untagged mode when ramping down a queue due to
Christoph> QUEUE FULL events has two problems:

Christoph>  - nothing in the midlayer or drivers ever moves back to
Christoph> tagged mode during queue ramp up.  - cmd_per_lun isn't the
Christoph> untagged queue depth for many modern drivers that can handle
Christoph> multiple untagged commands, and this is the only place in the
Christoph> midlayer assuming that.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 3/4] scsi: remove scsi_get_tag_type

[Martin K. Petersen]

>>>>> "Christoph" == Christoph Hellwig <hch@lst.de> writes:

Christoph> Both remaining users are better of just checking
Christoph> sdev->simple_tags directly.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 4/4] scsi: remove scsi_set_tag_type

[Martin K. Petersen]

>>>>> "Christoph" == Christoph Hellwig <hch@lst.de> writes:

Christoph> There is no benefit over just setting sdev->simple_tags
Christoph> directly.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 5/4] scsi: remove MSG_*_TAG defines

[Martin K. Petersen]

>>>>> "Christoph" == Christoph Hellwig <hch@infradead.org> writes:

Christoph> For SPI drivers use the message defintions from scsi.c, and
Christoph> for target drivers introduce a new TCM_*_TAG namespace.

s/defintions/definitions/

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 1/4] scsi: remove ->change_queue_type method

[Christoph Hellwig]

On Wed, Dec 03, 2014 at 02:32:04PM +0100, Hannes Reinecke wrote:
> Why not setting the attribute to S_IRUGO always and drop the 'store'
> method altogether?

For now I'm printing a warning if someone writes to it.  I the long
run we can simply mark it r/o.