[openib-general] [PATCH] IB/SRP set initiator_extention from user space

[Ishai Rabinovitz]

There is a need for an initiator to connect to the same target
several times, e.g., once from each IB port of the target.

Some targets do not support multichannel. In order to work with them as well:

1) Use port_guid instead of node_guid.
2) Allow the user to set the identifier_extension when providing the
target attributes. 

Signed-off-by: Ishai Rabinovitz <ishai at mellanox.co.il>

---

Roland, Madhu and MST,

I think this summarizes our discussion.

Index: last_stable/drivers/infiniband/ulp/srp/ib_srp.c
===================================================================
--- last_stable.orig/drivers/infiniband/ulp/srp/ib_srp.c	2006-10-03 15:38:16.000000000 +0200
+++ last_stable/drivers/infiniband/ulp/srp/ib_srp.c	2006-10-03 18:10:34.000000000 +0200
@@ -329,25 +329,29 @@ static int srp_send_req(struct srp_targe
 	req->priv.req_it_iu_len = cpu_to_be32(srp_max_iu_len);
 	req->priv.req_buf_fmt 	= cpu_to_be16(SRP_BUF_FORMAT_DIRECT |
 					      SRP_BUF_FORMAT_INDIRECT);
+
 	/*
 	 * In the published SRP specification (draft rev. 16a), the 
 	 * port identifier format is 8 bytes of ID extension followed
-	 * by 8 bytes of GUID.  Older drafts put the two halves in the
-	 * opposite order, so that the GUID comes first.
+	 * by 8 bytes of port GUID.  Older drafts put the two halves in the
+	 * opposite order, so that the port GUID comes first.
 	 *
 	 * Targets conforming to these obsolete drafts can be
 	 * recognized by the I/O Class they report.
 	 */
+
 	if (target->io_class == SRP_REV10_IB_IO_CLASS) {
 		memcpy(req->priv.initiator_port_id,
-		       target->srp_host->initiator_port_id + 8, 8);
+		       &target->path.sgid.global.interface_id, 8);
 		memcpy(req->priv.initiator_port_id + 8,
-		       target->srp_host->initiator_port_id, 8);
+		       &target->initiator_ext, 8);
 		memcpy(req->priv.target_port_id,     &target->ioc_guid, 8);
 		memcpy(req->priv.target_port_id + 8, &target->id_ext, 8);
 	} else {
 		memcpy(req->priv.initiator_port_id,
-		       target->srp_host->initiator_port_id, 16);
+		       &target->initiator_ext, 8);
+		memcpy(req->priv.initiator_port_id + 8,
+		       &target->path.sgid.global.interface_id, 8);
 		memcpy(req->priv.target_port_id,     &target->id_ext, 8);
 		memcpy(req->priv.target_port_id + 8, &target->ioc_guid, 8);
 	}
@@ -1557,6 +1561,7 @@ enum {
 	SRP_OPT_MAX_SECT	= 1 << 5,
 	SRP_OPT_MAX_CMD_PER_LUN	= 1 << 6,
 	SRP_OPT_IO_CLASS	= 1 << 7,
+	SRP_OPT_INITIATOR_EXT	= 1 << 8,
 	SRP_OPT_ALL		= (SRP_OPT_ID_EXT	|
 				   SRP_OPT_IOC_GUID	|
 				   SRP_OPT_DGID		|
@@ -1573,6 +1578,7 @@ static match_table_t srp_opt_tokens = {
 	{ SRP_OPT_MAX_SECT,		"max_sect=%d" 		},
 	{ SRP_OPT_MAX_CMD_PER_LUN,	"max_cmd_per_lun=%d" 	},
 	{ SRP_OPT_IO_CLASS,		"io_class=%x"		},
+	{ SRP_OPT_INITIATOR_EXT,	"initiator_ext=%s"	},
 	{ SRP_OPT_ERR,			NULL 			}
 };
 
@@ -1672,6 +1678,12 @@ static int srp_parse_options(const char 
 			target->io_class = token;
 			break;
 
+		case SRP_OPT_INITIATOR_EXT:
+			p = match_strdup(args);
+			target->initiator_ext = cpu_to_be64(simple_strtoull(p, NULL, 16));
+			kfree(p);
+			break;
+
 		default:
 			printk(KERN_WARNING PFX "unknown parameter or missing value "
 			       "'%s' in target creation request\n", p);
@@ -1820,9 +1832,6 @@ static struct srp_host *srp_add_port(str
 	host->dev  = device;
 	host->port = port;
 
-	host->initiator_port_id[7] = port;
-	memcpy(host->initiator_port_id + 8, &device->dev->node_guid, 8);
-
 	host->class_dev.class = &srp_class;
 	host->class_dev.dev   = device->dev->dma_device;
 	snprintf(host->class_dev.class_id, BUS_ID_SIZE, "srp-%s-%d",
Index: last_stable/drivers/infiniband/ulp/srp/ib_srp.h
===================================================================
--- last_stable.orig/drivers/infiniband/ulp/srp/ib_srp.h	2006-10-03 15:38:16.000000000 +0200
+++ last_stable/drivers/infiniband/ulp/srp/ib_srp.h	2006-10-03 18:05:50.000000000 +0200
@@ -91,7 +91,6 @@ struct srp_device {
 };
 
 struct srp_host {
-	u8			initiator_port_id[16];
 	struct srp_device      *dev;
 	u8			port;
 	struct class_device	class_dev;
@@ -122,6 +121,7 @@ struct srp_target_port {
 	__be64			id_ext;
 	__be64			ioc_guid;
 	__be64			service_id;
+	__be64			initiator_ext;
 	u16			io_class;
 	struct srp_host	       *srp_host;
 	struct Scsi_Host       *scsi_host;
-- 
Ishai Rabinovitz