[openib-general] [PATCH 04/12] SRP: Changing ibsrpdm

[Ishai Rabinovitz]

Do not add the same target twice.

Signed-off-by: Ishai Rabinovitz <ishai at mellanox.co.il>
Index: last_stable/drivers/infiniband/ulp/srp/ib_srp.c
===================================================================
--- last_stable.orig/drivers/infiniband/ulp/srp/ib_srp.c	2006-04-25 15:17:34.000000000 +0300
+++ last_stable/drivers/infiniband/ulp/srp/ib_srp.c	2006-04-25 15:19:37.000000000 +0300
@@ -1478,7 +1478,8 @@ static int srp_parse_options(const char 
 				printk(KERN_WARNING PFX "bad max sect parameter '%s'\n", p);
 				goto out;
 			}
-			target->scsi_host->max_sectors = token;
+			if (target->scsi_host != NULL)
+				target->scsi_host->max_sectors = token;
 			break;
 
 		default:
@@ -1503,20 +1504,89 @@ out:
 	return ret;
 }
 
+/* srp_find_target - If the target exists return it in target,
+		      otherwise target is set to NULL.
+		      host->target_mutex should be hold */
+static int srp_find_target(const char *buf, struct srp_host *host,
+			   struct srp_target_port **target)
+{
+	struct srp_target_port *target_to_find, *curr_target;
+	int ret, i;
+
+	target_to_find = kzalloc(sizeof *target_to_find, GFP_KERNEL);
+	ret = srp_parse_options(buf, target_to_find);
+	if (ret)
+	        goto free;
+
+	list_for_each_entry(curr_target, &host->target_list, list)
+	        if (target_to_find->ioc_guid == curr_target->ioc_guid &&
+		    target_to_find->id_ext == curr_target->id_ext &&
+		    target_to_find->path.pkey == curr_target->path.pkey &&
+		    target_to_find->service_id == curr_target->service_id) {
+		        for (i = 0; i < 16; ++i)
+		                if (target_to_find->path.dgid.raw[i] != curr_target->path.dgid.raw[i])
+				        break;
+			if (i == 16) {
+				*target = curr_target;
+				goto free;
+			}
+		}
+
+	*target = NULL;
+
+free:
+	kfree(target_to_find);
+	return 0;
+}
+
 static ssize_t srp_create_target(struct class_device *class_dev,
 				 const char *buf, size_t count)
 {
 	struct srp_host *host =
 		container_of(class_dev, struct srp_host, class_dev);
 	struct Scsi_Host *target_host;
-	struct srp_target_port *target;
+	struct srp_target_port *target, *existing_target = NULL;
 	int ret;
 	int i;
 
+	/* first check if the target already exists */
+
+	mutex_lock(&host->target_mutex);
+	ret = srp_find_target(buf, host, &existing_target);
+	if (ret)
+		goto unlock_mutex;
+
+	if (existing_target) {
+		/* target already exists */
+		spin_lock_irq(existing_target->scsi_host->host_lock);
+		switch (existing_target->state) {
+		case SRP_TARGET_LIVE:
+			printk(KERN_WARNING PFX "target %s already exists\n",
+			       buf);
+			ret = -EEXIST;
+			break;
+		case SRP_TARGET_CONNECTING:
+		        /* It is in the middle of reconnecting */
+			ret = -EALREADY;
+			break;
+		case SRP_TARGET_DEAD:
+		        /* It will be removed soon - create a new one */
+		case SRP_TARGET_REMOVED:
+			/* target is dead, create a new one */
+			break;
+		}
+ 		spin_unlock_irq(existing_target->scsi_host->host_lock);
+		if (ret)
+			goto unlock_mutex;
+	}
+
+	/* really create the target */
 	target_host = scsi_host_alloc(&srp_template,
 				      sizeof (struct srp_target_port));
-	if (!target_host)
-		return -ENOMEM;
+	if (!target_host) {
+		ret = -ENOMEM;
+		goto unlock_mutex;
+	}
 
 	target_host->max_lun = SRP_MAX_LUN;
 
@@ -1533,7 +1603,7 @@ static ssize_t srp_create_target(struct 
 
 	ret = srp_parse_options(buf, target);
 	if (ret)
-		goto err;
+		goto err_put_scsi_host;
 
 	ib_get_cached_gid(host->dev, host->port, 0, &target->path.sgid);
 
@@ -1554,7 +1624,7 @@ static ssize_t srp_create_target(struct 
 
 	ret = srp_create_target_ib(target);
 	if (ret)
-		goto err;
+		goto err_put_scsi_host;
 
 	target->cm_id = ib_create_cm_id(host->dev, srp_cm_handler, target);
 	if (IS_ERR(target->cm_id)) {
@@ -1572,7 +1642,8 @@ static ssize_t srp_create_target(struct 
 	if (ret)
 		goto err_disconnect;
 
-	return count;
+	ret = count;
+	goto unlock_mutex;
 
 err_disconnect:
 	srp_disconnect_target(target);
@@ -1583,9 +1654,12 @@ err_cm_id:
 err_free:
 	srp_free_target_ib(target);
 
-err:
+err_put_scsi_host:
 	scsi_host_put(target_host);
 
+unlock_mutex:
+	mutex_unlock(&host->target_mutex);
+
 	return ret;
 }
 
-- 
Ishai Rabinovitz