[SCSI] cxgb3i, iser, iscsi_tcp: set target can queue

Set target can queue limit to the number of preallocated
session tasks we have.

This along with the cxgb3i can_queue patch will fix a throughput
problem where it could only queue one LU worth of data at a time.
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

drivers/infiniband/ulp/iser/iscsi_iser.c

@@ -599,6 +599,7 @@ static struct scsi_host_template iscsi_iser_sht = {
 	.eh_abort_handler       = iscsi_eh_abort,
 	.eh_device_reset_handler= iscsi_eh_device_reset,
 	.eh_target_reset_handler= iscsi_eh_target_reset,
+	.target_alloc		= iscsi_target_alloc,
 	.use_clustering         = DISABLE_CLUSTERING,
 	.proc_name              = "iscsi_iser",
 	.this_id                = -1,

drivers/scsi/cxgb3i/cxgb3i_iscsi.c

@@ -883,6 +883,7 @@ static struct scsi_host_template cxgb3i_host_template = {
 	.eh_abort_handler	= iscsi_eh_abort,
 	.eh_device_reset_handler = iscsi_eh_device_reset,
 	.eh_target_reset_handler = iscsi_eh_target_reset,
+	.target_alloc		= iscsi_target_alloc,
 	.use_clustering		= DISABLE_CLUSTERING,
 	.this_id		= -1,
 };

drivers/scsi/iscsi_tcp.c

@@ -851,6 +851,7 @@ static struct scsi_host_template iscsi_sw_tcp_sht = {
 	.use_clustering         = DISABLE_CLUSTERING,
 	.slave_alloc            = iscsi_sw_tcp_slave_alloc,
 	.slave_configure        = iscsi_sw_tcp_slave_configure,
+	.target_alloc		= iscsi_target_alloc,
 	.proc_name		= "iscsi_tcp",
 	.this_id		= -1,
 };

drivers/scsi/libiscsi.c

@@ -1463,6 +1463,16 @@ int iscsi_change_queue_depth(struct scsi_device *sdev, int depth)
 }
 EXPORT_SYMBOL_GPL(iscsi_change_queue_depth);
 
+int iscsi_target_alloc(struct scsi_target *starget)
+{
+	struct iscsi_cls_session *cls_session = starget_to_session(starget);
+	struct iscsi_session *session = cls_session->dd_data;
+
+	starget->can_queue = session->scsi_cmds_max;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(iscsi_target_alloc);
+
 void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
 {
 	struct iscsi_session *session = cls_session->dd_data;

include/scsi/libiscsi.h

@@ -36,6 +36,7 @@ struct scsi_transport_template;
 struct scsi_host_template;
 struct scsi_device;
 struct Scsi_Host;
+struct scsi_target;
 struct scsi_cmnd;
 struct socket;
 struct iscsi_transport;
@@ -350,6 +351,7 @@ extern struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
 					  bool xmit_can_sleep);
 extern void iscsi_host_remove(struct Scsi_Host *shost);
 extern void iscsi_host_free(struct Scsi_Host *shost);
+extern int iscsi_target_alloc(struct scsi_target *starget);
 
 /*
  * session management