target: Convert demo-mode only drivers to target_alloc_session

This patch converts existing loopback, usb-gadget, and
xen-scsiback demo-mode only fabric drivers to use the
new target_alloc_session API caller.

This includes adding a new alloc_session callback for
fabric driver internal nexus pointer assignments.

(Fixes for early for-next nexus breakage - Dan Carpenter)

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Acked-by: Juergen Gross <jgross@suse.com>
Tested-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Tested-by: Chris Boot <bootc@bootc.net>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/loopback/tcm_loop.c

@@ -802,58 +802,48 @@ static struct configfs_attribute *tcm_loop_tpg_attrib_attrs[] = {
 
 /* Start items for tcm_loop_nexus_cit */
 
+static int tcm_loop_alloc_sess_cb(struct se_portal_group *se_tpg,
+				  struct se_session *se_sess, void *p)
+{
+	struct tcm_loop_tpg *tl_tpg = container_of(se_tpg,
+					struct tcm_loop_tpg, tl_se_tpg);
+
+	tl_tpg->tl_nexus = p;
+	return 0;
+}
+
 static int tcm_loop_make_nexus(
 	struct tcm_loop_tpg *tl_tpg,
 	const char *name)
 {
-	struct se_portal_group *se_tpg;
 	struct tcm_loop_hba *tl_hba = tl_tpg->tl_hba;
 	struct tcm_loop_nexus *tl_nexus;
-	int ret = -ENOMEM;
+	int ret;
 
 	if (tl_tpg->tl_nexus) {
 		pr_debug("tl_tpg->tl_nexus already exists\n");
 		return -EEXIST;
 	}
-	se_tpg = &tl_tpg->tl_se_tpg;
 
 	tl_nexus = kzalloc(sizeof(struct tcm_loop_nexus), GFP_KERNEL);
 	if (!tl_nexus) {
 		pr_err("Unable to allocate struct tcm_loop_nexus\n");
 		return -ENOMEM;
 	}
-	/*
-	 * Initialize the struct se_session pointer
-	 */
-	tl_nexus->se_sess = transport_init_session(
-				TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
+
+	tl_nexus->se_sess = target_alloc_session(&tl_tpg->tl_se_tpg, 0, 0,
+					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
+					name, tl_nexus, tcm_loop_alloc_sess_cb);
 	if (IS_ERR(tl_nexus->se_sess)) {
 		ret = PTR_ERR(tl_nexus->se_sess);
-		goto out;
+		kfree(tl_nexus);
+		return ret;
 	}
-	/*
-	 * Since we are running in 'demo mode' this call with generate a
-	 * struct se_node_acl for the tcm_loop struct se_portal_group with the SCSI
-	 * Initiator port name of the passed configfs group 'name'.
-	 */
-	tl_nexus->se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
-				se_tpg, (unsigned char *)name);
-	if (!tl_nexus->se_sess->se_node_acl) {
-		transport_free_session(tl_nexus->se_sess);
-		goto out;
-	}
-	/* Now, register the I_T Nexus as active. */
-	transport_register_session(se_tpg, tl_nexus->se_sess->se_node_acl,
-			tl_nexus->se_sess, tl_nexus);
-	tl_tpg->tl_nexus = tl_nexus;
+
 	pr_debug("TCM_Loop_ConfigFS: Established I_T Nexus to emulated"
 		" %s Initiator Port: %s\n", tcm_loop_dump_proto_id(tl_hba),
 		name);
 	return 0;
-
-out:
-	kfree(tl_nexus);
-	return ret;
 }
 
 static int tcm_loop_drop_nexus(

drivers/target/sbp/sbp_target.c

@@ -196,45 +196,28 @@ static struct sbp_session *sbp_session_create(
 	struct sbp_session *sess;
 	int ret;
 	char guid_str[17];
-	struct se_node_acl *se_nacl;
+
+	snprintf(guid_str, sizeof(guid_str), "%016llx", guid);
 
 	sess = kmalloc(sizeof(*sess), GFP_KERNEL);
 	if (!sess) {
 		pr_err("failed to allocate session descriptor\n");
 		return ERR_PTR(-ENOMEM);
 	}
+	spin_lock_init(&sess->lock);
+	INIT_LIST_HEAD(&sess->login_list);
+	INIT_DELAYED_WORK(&sess->maint_work, session_maintenance_work);
+	sess->guid = guid;
 
-	sess->se_sess = transport_init_session(TARGET_PROT_NORMAL);
+	sess->se_sess = target_alloc_session(&tpg->se_tpg, 0, 0, TARGET_PROT_NORMAL,
+					     guid_str, sess, NULL);
 	if (IS_ERR(sess->se_sess)) {
 		pr_err("failed to init se_session\n");
-
 		ret = PTR_ERR(sess->se_sess);
 		kfree(sess);
 		return ERR_PTR(ret);
 	}
 
-	snprintf(guid_str, sizeof(guid_str), "%016llx", guid);
-
-	se_nacl = core_tpg_check_initiator_node_acl(&tpg->se_tpg, guid_str);
-	if (!se_nacl) {
-		pr_warn("Node ACL not found for %s\n", guid_str);
-
-		transport_free_session(sess->se_sess);
-		kfree(sess);
-
-		return ERR_PTR(-EPERM);
-	}
-
-	sess->se_sess->se_node_acl = se_nacl;
-
-	spin_lock_init(&sess->lock);
-	INIT_LIST_HEAD(&sess->login_list);
-	INIT_DELAYED_WORK(&sess->maint_work, session_maintenance_work);
-
-	sess->guid = guid;
-
-	transport_register_session(&tpg->se_tpg, se_nacl, sess->se_sess, sess);
-
 	return sess;
 }
 

drivers/usb/gadget/function/f_tcm.c

@@ -1579,55 +1579,46 @@ static ssize_t tcm_usbg_tpg_nexus_show(struct config_item *item, char *page)
 	return ret;
 }
 
+static int usbg_alloc_sess_cb(struct se_portal_group *se_tpg,
+			      struct se_session *se_sess, void *p)
+{
+	struct usbg_tpg *tpg = container_of(se_tpg,
+				struct usbg_tpg, se_tpg);
+
+	tpg->tpg_nexus = p;
+	return 0;
+}
+
 static int tcm_usbg_make_nexus(struct usbg_tpg *tpg, char *name)
 {
-	struct se_portal_group *se_tpg;
 	struct tcm_usbg_nexus *tv_nexus;
-	int ret;
+	int ret = 0;
 
 	mutex_lock(&tpg->tpg_mutex);
 	if (tpg->tpg_nexus) {
 		ret = -EEXIST;
 		pr_debug("tpg->tpg_nexus already exists\n");
-		goto err_unlock;
+		goto out_unlock;
 	}
-	se_tpg = &tpg->se_tpg;
 
-	ret = -ENOMEM;
 	tv_nexus = kzalloc(sizeof(*tv_nexus), GFP_KERNEL);
-	if (!tv_nexus)
-		goto err_unlock;
-	tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL);
-	if (IS_ERR(tv_nexus->tvn_se_sess))
-		goto err_free;
+	if (!tv_nexus) {
+		ret = -ENOMEM;
+		goto out_unlock;
+	}
 
-	/*
-	 * Since we are running in 'demo mode' this call with generate a
-	 * struct se_node_acl for the tcm_vhost struct se_portal_group with
-	 * the SCSI Initiator port name of the passed configfs group 'name'.
-	 */
-	tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
-			se_tpg, name);
-	if (!tv_nexus->tvn_se_sess->se_node_acl) {
+	tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg, 0, 0,
+						     TARGET_PROT_NORMAL, name,
+						     tv_nexus, usbg_alloc_sess_cb);
+	if (IS_ERR(tv_nexus->tvn_se_sess)) {
 #define MAKE_NEXUS_MSG "core_tpg_check_initiator_node_acl() failed for %s\n"
 		pr_debug(MAKE_NEXUS_MSG, name);
 #undef MAKE_NEXUS_MSG
-		goto err_session;
+		ret = PTR_ERR(tv_nexus->tvn_se_sess);
+		kfree(tv_nexus);
 	}
-	/*
-	 * Now register the TCM vHost virtual I_T Nexus as active.
-	 */
-	transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
-			tv_nexus->tvn_se_sess, tv_nexus);
-	tpg->tpg_nexus = tv_nexus;
-	mutex_unlock(&tpg->tpg_mutex);
-	return 0;
 
-err_session:
-	transport_free_session(tv_nexus->tvn_se_sess);
-err_free:
-	kfree(tv_nexus);
-err_unlock:
+out_unlock:
 	mutex_unlock(&tpg->tpg_mutex);
 	return ret;
 }

drivers/xen/xen-scsiback.c

@@ -1482,61 +1482,47 @@ static struct configfs_attribute *scsiback_param_attrs[] = {
 	NULL,
 };
 
+static int scsiback_alloc_sess_cb(struct se_portal_group *se_tpg,
+				  struct se_session *se_sess, void *p)
+{
+	struct scsiback_tpg *tpg = container_of(se_tpg,
+				struct scsiback_tpg, se_tpg);
+
+	tpg->tpg_nexus = p;
+	return 0;
+}
+
 static int scsiback_make_nexus(struct scsiback_tpg *tpg,
 				const char *name)
 {
-	struct se_portal_group *se_tpg;
-	struct se_session *se_sess;
 	struct scsiback_nexus *tv_nexus;
+	int ret = 0;
 
 	mutex_lock(&tpg->tv_tpg_mutex);
 	if (tpg->tpg_nexus) {
-		mutex_unlock(&tpg->tv_tpg_mutex);
 		pr_debug("tpg->tpg_nexus already exists\n");
-		return -EEXIST;
+		ret = -EEXIST;
+		goto out_unlock;
 	}
-	se_tpg = &tpg->se_tpg;
 
 	tv_nexus = kzalloc(sizeof(struct scsiback_nexus), GFP_KERNEL);
 	if (!tv_nexus) {
-		mutex_unlock(&tpg->tv_tpg_mutex);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_unlock;
 	}
-	/*
-	 * Initialize the struct se_session pointer
-	 */
-	tv_nexus->tvn_se_sess = transport_init_session(TARGET_PROT_NORMAL);
+
+	tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg, 0, 0,
+						     TARGET_PROT_NORMAL, name,
+						     tv_nexus, scsiback_alloc_sess_cb);
 	if (IS_ERR(tv_nexus->tvn_se_sess)) {
-		mutex_unlock(&tpg->tv_tpg_mutex);
 		kfree(tv_nexus);
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto out_unlock;
 	}
-	se_sess = tv_nexus->tvn_se_sess;
-	/*
-	 * Since we are running in 'demo mode' this call with generate a
-	 * struct se_node_acl for the scsiback struct se_portal_group with
-	 * the SCSI Initiator port name of the passed configfs group 'name'.
-	 */
-	tv_nexus->tvn_se_sess->se_node_acl = core_tpg_check_initiator_node_acl(
-				se_tpg, (unsigned char *)name);
-	if (!tv_nexus->tvn_se_sess->se_node_acl) {
-		mutex_unlock(&tpg->tv_tpg_mutex);
-		pr_debug("core_tpg_check_initiator_node_acl() failed for %s\n",
-			 name);
-		goto out;
-	}
-	/* Now register the TCM pvscsi virtual I_T Nexus as active. */
-	transport_register_session(se_tpg, tv_nexus->tvn_se_sess->se_node_acl,
-			tv_nexus->tvn_se_sess, tv_nexus);
-	tpg->tpg_nexus = tv_nexus;
 
+out_unlock:
 	mutex_unlock(&tpg->tv_tpg_mutex);
-	return 0;
-
-out:
-	transport_free_session(se_sess);
-	kfree(tv_nexus);
-	return -ENOMEM;
+	return ret;
 }
 
 static int scsiback_drop_nexus(struct scsiback_tpg *tpg)