scsi: don't allow setting of queue_depth bigger than can_queue

We won't ever queue more commands than the host allows.  Instead of
letting drivers either reject or ignore this case handle it in
common code.  Note that various driver use internal constant or
variables that are assigned to both shost->can_queue and checked
in ->change_queue_depth - I did remove those checks as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Hannes Reinecke <hare@suse.de>

9 files changed, 3 insertions, 30 deletions

diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 98a30355..8d13a19 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -2410,14 +2410,8 @@ static int srp_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
 static int
 srp_change_queue_depth(struct scsi_device *sdev, int qdepth, int reason)
 {
-	struct Scsi_Host *shost = sdev->host;
-	int max_depth;
-
-	max_depth = shost->can_queue;
 	if (!sdev->tagged_supported)
-		max_depth = 1;
-	if (qdepth > max_depth)
-		qdepth = max_depth;
+		qdepth = 1;
 	scsi_adjust_queue_depth(sdev, qdepth);
 	return sdev->queue_depth;
 }
diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
index 02021f5..1cf3703 100644
--- a/drivers/scsi/3w-9xxx.c
+++ b/drivers/scsi/3w-9xxx.c
@@ -196,8 +196,6 @@ static int twa_change_queue_depth(struct scsi_device *sdev, int queue_depth,
 	if (reason != SCSI_QDEPTH_DEFAULT)
 		return -EOPNOTSUPP;
 
-	if (queue_depth > TW_Q_LENGTH-2)
-		queue_depth = TW_Q_LENGTH-2;
 	scsi_adjust_queue_depth(sdev, queue_depth);
 	return queue_depth;
 } /* End twa_change_queue_depth() */
diff --git a/drivers/scsi/3w-sas.c b/drivers/scsi/3w-sas.c
index ac0c254..547756b 100644
--- a/drivers/scsi/3w-sas.c
+++ b/drivers/scsi/3w-sas.c
@@ -198,8 +198,6 @@ static int twl_change_queue_depth(struct scsi_device *sdev, int queue_depth,
 	if (reason != SCSI_QDEPTH_DEFAULT)
 		return -EOPNOTSUPP;
 
-	if (queue_depth > TW_Q_LENGTH-2)
-		queue_depth = TW_Q_LENGTH-2;
 	scsi_adjust_queue_depth(sdev, queue_depth);
 	return queue_depth;
 } /* End twl_change_queue_depth() */
diff --git a/drivers/scsi/3w-xxxx.c b/drivers/scsi/3w-xxxx.c
index 1ec9ad9..261a4c1 100644
--- a/drivers/scsi/3w-xxxx.c
+++ b/drivers/scsi/3w-xxxx.c
@@ -530,8 +530,6 @@ static int tw_change_queue_depth(struct scsi_device *sdev, int queue_depth,
 	if (reason != SCSI_QDEPTH_DEFAULT)
 		return -EOPNOTSUPP;
 
-	if (queue_depth > TW_Q_LENGTH-2)
-		queue_depth = TW_Q_LENGTH-2;
 	scsi_adjust_queue_depth(sdev, queue_depth);
 	return queue_depth;
 } /* End tw_change_queue_depth() */
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 3569f42..617f218 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -4082,11 +4082,6 @@ static int hpsa_change_queue_depth(struct scsi_device *sdev,
 	if (reason != SCSI_QDEPTH_DEFAULT)
 		return -ENOTSUPP;
 
-	if (qdepth < 1)
-		qdepth = 1;
-	else
-		if (qdepth > h->nr_cmds)
-			qdepth = h->nr_cmds;
 	scsi_adjust_queue_depth(sdev, qdepth);
 	return sdev->queue_depth;
 }
diff --git a/drivers/scsi/megaraid/megaraid_mbox.c b/drivers/scsi/megaraid/megaraid_mbox.c
index 6b077d8..d56eb9d 100644
--- a/drivers/scsi/megaraid/megaraid_mbox.c
+++ b/drivers/scsi/megaraid/megaraid_mbox.c
@@ -347,8 +347,6 @@ static int megaraid_change_queue_depth(struct scsi_device *sdev, int qdepth,
 	if (reason != SCSI_QDEPTH_DEFAULT)
 		return -EOPNOTSUPP;
 
-	if (qdepth > MBOX_MAX_SCSI_CMDS)
-		qdepth = MBOX_MAX_SCSI_CMDS;
 	scsi_adjust_queue_depth(sdev, qdepth);
 	return sdev->queue_depth;
 }
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c
index 3ccfbec..69a9dd6 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -2597,8 +2597,6 @@ static int megasas_change_queue_depth(struct scsi_device *sdev,
 	if (reason != SCSI_QDEPTH_DEFAULT)
 		return -EOPNOTSUPP;
 
-	if (queue_depth > sdev->host->can_queue)
-		queue_depth = sdev->host->can_queue;
 	scsi_adjust_queue_depth(sdev, queue_depth);
 
 	return queue_depth;
diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index 35d93b0..bffd5ab 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -877,7 +877,7 @@ sdev_store_queue_depth(struct device *dev, struct device_attribute *attr,
 
 	depth = simple_strtoul(buf, NULL, 0);
 
-	if (depth < 1)
+	if (depth < 1 || depth > sht->can_queue)
 		return -EINVAL;
 
 	retval = sht->change_queue_depth(sdev, depth,
diff --git a/drivers/scsi/vmw_pvscsi.c b/drivers/scsi/vmw_pvscsi.c
index 4a01c05..03ad24b 100644
--- a/drivers/scsi/vmw_pvscsi.c
+++ b/drivers/scsi/vmw_pvscsi.c
@@ -508,20 +508,14 @@ static int pvscsi_change_queue_depth(struct scsi_device *sdev,
 				     int qdepth,
 				     int reason)
 {
-	int max_depth;
-	struct Scsi_Host *shost = sdev->host;
-
 	if (reason != SCSI_QDEPTH_DEFAULT)
 		/*
 		 * We support only changing default.
 		 */
 		return -EOPNOTSUPP;
 
-	max_depth = shost->can_queue;
 	if (!sdev->tagged_supported)
-		max_depth = 1;
-	if (qdepth > max_depth)
-		qdepth = max_depth;
+		qdepth = 1;
 	scsi_adjust_queue_depth(sdev, qdepth);
 
 	if (sdev->inquiry_len > 7)