[SCSI] iscsi_tcp: remove DMA alignment restriction

Add a slave_configure function to iSCSI TCP to remove any DMA
alignment restriction.  This permits the use of direct IO from
arbitrary addresses.

Signed-off-by: Pete Wyckoff <pw@osc.edu>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/iscsi_tcp.c

@@ -36,6 +36,7 @@
 #include <linux/scatterlist.h>
 #include <net/tcp.h>
 #include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_transport_iscsi.h>
@@ -2184,6 +2185,12 @@ static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 	iscsi_session_teardown(cls_session);
 }
 
+static int iscsi_tcp_slave_configure(struct scsi_device *sdev)
+{
+	blk_queue_dma_alignment(sdev->request_queue, 0);
+	return 0;
+}
+
 static struct scsi_host_template iscsi_sht = {
 	.name			= "iSCSI Initiator over TCP/IP",
 	.queuecommand           = iscsi_queuecommand,
@@ -2195,6 +2202,7 @@ static struct scsi_host_template iscsi_sht = {
 	.eh_abort_handler       = iscsi_eh_abort,
 	.eh_host_reset_handler	= iscsi_eh_host_reset,
 	.use_clustering         = DISABLE_CLUSTERING,
+	.slave_configure        = iscsi_tcp_slave_configure,
 	.proc_name		= "iscsi_tcp",
 	.this_id		= -1,
 };