[PATCH] iscsi tcp set queue dma alignment to zero

[Pete Wyckoff <pw@osc.edu>]

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>
---
 drivers/scsi/iscsi_tcp.c |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 4376840..f48eedd 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -2132,6 +2132,16 @@ static void iscsi_tcp_session_destroy(struct iscsi_cls_session *cls_session)
 	iscsi_session_teardown(cls_session);
 }
 
+/*
+ * New device attached.  Turn off the DMA alignment restriction on
+ * the request queue.
+ */
+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,
@@ -2142,6 +2152,7 @@ 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,
 };
-- 
1.5.0.2