[PATCH-for-4.6 0/6] target: Introduce target_alloc_session helper

[PATCH-for-4.6 0/6] target: Introduce target_alloc_session helper

[Nicholas A. Bellinger]

From: Nicholas Bellinger <nab@linux-iscsi.org>

Hi folks,

As per HCH, consolidating se_session init -> lookup -> register
into a single helper has a number of benefits.

This version of the target_alloc_session() helper supports
percpu-ida tag allocation, and a (*callback)() for allowing
fabric driver code to complete internal setup before target
calls transport_register_session() to complete the operation.

That said, here's a first shot for the tree wide-conversion,
which should be considered post v4.5 material at this point,
considering it's purely a mechanical change.

Please review,

--nab

Christoph Hellwig (1):
  target: Convert demo-mode only drivers to target_alloc_session

Nicholas Bellinger (5):
  target: Add target_alloc_session() helper function
  vhost/scsi: Convert to target_alloc_session usage
  tcm_qla2xxx: Convert to target_alloc_session usage
  tcm_fc: Convert to target_alloc_session usage
  ib_srpt: Convert to target_alloc_session usage

 drivers/infiniband/ulp/srpt/ib_srpt.c  | 23 +++-----
 drivers/scsi/qla2xxx/qla_target.c      |  8 +--
 drivers/scsi/qla2xxx/qla_target.h      |  2 +-
 drivers/scsi/qla2xxx/tcm_qla2xxx.c     | 79 +++++++++++++--------------
 drivers/target/loopback/tcm_loop.c     | 35 +++---------
 drivers/target/sbp/sbp_target.c        | 33 +++---------
 drivers/target/target_core_transport.c | 55 +++++++++++++++++++
 drivers/target/tcm_fc/tfc_sess.c       | 47 ++++++++--------
 drivers/usb/gadget/function/f_tcm.c    | 45 +++++-----------
 drivers/vhost/scsi.c                   | 99 ++++++++++++++--------------------
 drivers/xen/xen-scsiback.c             | 51 +++++-------------
 include/target/target_core_fabric.h    |  6 +++
 12 files changed, 218 insertions(+), 265 deletions(-)

-- 
1.9.1

[PATCH-for-4.6 1/6] target: Add target_alloc_session() helper function

[Nicholas A. Bellinger]

From: Nicholas Bellinger <nab@linux-iscsi.org>

Based on HCH's original patch, this adds a full version to
support percpu-ida tag pre-allocation and callback function
pointer into fabric driver code to complete session setup.

Reported-by: Christoph Hellwig <hch@lst.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Andy Grover <agrover@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/target_core_transport.c | 55 ++++++++++++++++++++++++++++++++++
 include/target/target_core_fabric.h    |  6 ++++
 2 files changed, 61 insertions(+)

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index c5035b9..fd4404f6 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -374,6 +374,61 @@ void transport_register_session(
 }
 EXPORT_SYMBOL(transport_register_session);
 
+struct se_session *
+target_alloc_session(struct se_portal_group *tpg,
+		     unsigned int tag_num, unsigned int tag_size,
+		     enum target_prot_op prot_op,
+		     const char *initiatorname, void *private,
+		     int (*callback)(struct se_portal_group *,
+				     struct se_session *, void *))
+{
+	struct se_session *sess;
+
+	if (tag_num != 0 && !tag_size) {
+		pr_err("target_alloc_session called with percpu-ida tag_num:"
+		       " %u, but zero tag_size\n", tag_num);
+		return ERR_PTR(-EINVAL);
+	}
+	if (!tag_num && tag_size) {
+		pr_err("target_alloc_session called with percpu-ida tag_size:"
+		       " %u, but zero tag_num\n", tag_size);
+		return ERR_PTR(-EINVAL);
+	}
+	/*
+	 * If the fabric driver is using percpu-ida based pre allocation
+	 * of I/O descriptor tags, go ahead and perform that setup now..
+	 */
+	if (tag_num != 0)
+		sess = transport_init_session_tags(tag_num, tag_size, prot_op);
+	else
+		sess = transport_init_session(prot_op);
+
+	if (IS_ERR(sess))
+		return sess;
+
+	sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
+					(unsigned char *)initiatorname);
+	if (!sess->se_node_acl) {
+		transport_free_session(sess);
+		return ERR_PTR(-EACCES);
+	}
+	/*
+	 * Go ahead and perform any remaining fabric setup that is
+	 * required before transport_register_session().
+	 */
+	if (callback != NULL) {
+		int rc = callback(tpg, sess, private);
+		if (rc) {
+			transport_free_session(sess);
+			return ERR_PTR(rc);
+		}
+	}
+
+	transport_register_session(tpg, sess->se_node_acl, sess, private);
+	return sess;
+}
+EXPORT_SYMBOL(target_alloc_session);
+
 static void target_release_session(struct kref *kref)
 {
 	struct se_session *se_sess = container_of(kref,
diff --git a/include/target/target_core_fabric.h b/include/target/target_core_fabric.h
index dc6b09e..7d59273 100644
--- a/include/target/target_core_fabric.h
+++ b/include/target/target_core_fabric.h
@@ -108,6 +108,12 @@ void target_unregister_template(const struct target_core_fabric_ops *fo);
 int target_depend_item(struct config_item *item);
 void target_undepend_item(struct config_item *item);
 
+struct se_session *target_alloc_session(struct se_portal_group *,
+		unsigned int, unsigned int, enum target_prot_op prot_op,
+		const char *, void *,
+		int (*callback)(struct se_portal_group *,
+				struct se_session *, void *));
+
 struct se_session *transport_init_session(enum target_prot_op);
 int transport_alloc_session_tags(struct se_session *, unsigned int,
 		unsigned int);
-- 
1.9.1

[PATCH-for-4.6 2/6] target: Convert demo-mode only drivers to target_alloc_session

[Nicholas A. Bellinger]

From: Christoph Hellwig <hch@lst.de>

Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de> # loopback
Cc: Chris Boot <bootc@bootc.net> # sbp-target
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> # usb-gadget
Cc: Andrzej Pietrasiewicz <andrzej.p@samsung.com> # usb-gadget
Cc: Juergen Gross <jgross@suse.com> # xen-scsiback
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/loopback/tcm_loop.c  | 35 +++++--------------------
 drivers/target/sbp/sbp_target.c     | 33 ++++++------------------
 drivers/usb/gadget/function/f_tcm.c | 45 ++++++++++----------------------
 drivers/xen/xen-scsiback.c          | 51 ++++++++++---------------------------
 4 files changed, 42 insertions(+), 122 deletions(-)

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index d41a5c3..0216c75 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -806,54 +806,33 @@ 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;
 
 	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, NULL);
 	if (IS_ERR(tl_nexus->se_sess)) {
-		ret = PTR_ERR(tl_nexus->se_sess);
-		goto out;
-	}
-	/*
-	 * 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;
+		kfree(tl_nexus);
+		return PTR_ERR(tl_nexus->se_sess);
 	}
-	/* 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(
diff --git a/drivers/target/sbp/sbp_target.c b/drivers/target/sbp/sbp_target.c
index 3072f1a..ddd3398 100644
--- a/drivers/target/sbp/sbp_target.c
+++ b/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;
 }
 
diff --git a/drivers/usb/gadget/function/f_tcm.c b/drivers/usb/gadget/function/f_tcm.c
index bad007b5..2e8b91d 100644
--- a/drivers/usb/gadget/function/f_tcm.c
+++ b/drivers/usb/gadget/function/f_tcm.c
@@ -1581,53 +1581,34 @@ out:
 
 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, NULL);
+	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;
+		kfree(tv_nexus);
+		ret = PTR_ERR(tv_nexus->tvn_se_sess);
 	}
-	/*
-	 * 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;
 }
diff --git a/drivers/xen/xen-scsiback.c b/drivers/xen/xen-scsiback.c
index 43bcae8..594f8a7 100644
--- a/drivers/xen/xen-scsiback.c
+++ b/drivers/xen/xen-scsiback.c
@@ -1485,58 +1485,35 @@ static struct configfs_attribute *scsiback_param_attrs[] = {
 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, NULL);
 	if (IS_ERR(tv_nexus->tvn_se_sess)) {
-		mutex_unlock(&tpg->tv_tpg_mutex);
 		kfree(tv_nexus);
-		return -ENOMEM;
-	}
-	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;
+		ret = -ENOMEM;
+		goto out_unlock;
 	}
-	/* 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;
 
+	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)
-- 
1.9.1

[PATCH-for-4.6 3/6] vhost/scsi: Convert to target_alloc_session usage

[Nicholas A. Bellinger]

From: Nicholas Bellinger <nab@linux-iscsi.org>

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/vhost/scsi.c | 99 ++++++++++++++++++++++------------------------------
 1 file changed, 41 insertions(+), 58 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 29cfc57..cd5f20f 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -1664,8 +1664,7 @@ static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
 	mutex_unlock(&vhost_scsi_mutex);
 }
 
-static void vhost_scsi_free_cmd_map_res(struct vhost_scsi_nexus *nexus,
-				       struct se_session *se_sess)
+static void vhost_scsi_free_cmd_map_res(struct se_session *se_sess)
 {
 	struct vhost_scsi_cmd *tv_cmd;
 	unsigned int i;
@@ -1721,98 +1720,82 @@ static struct configfs_attribute *vhost_scsi_tpg_attrib_attrs[] = {
 	NULL,
 };
 
-static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
-				const char *name)
+static int vhost_scsi_nexus_cb(struct se_portal_group *se_tpg,
+			       struct se_session *se_sess, void *p)
 {
-	struct se_portal_group *se_tpg;
-	struct se_session *se_sess;
-	struct vhost_scsi_nexus *tv_nexus;
 	struct vhost_scsi_cmd *tv_cmd;
 	unsigned int i;
 
-	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;
-	}
-	se_tpg = &tpg->se_tpg;
-
-	tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
-	if (!tv_nexus) {
-		mutex_unlock(&tpg->tv_tpg_mutex);
-		pr_err("Unable to allocate struct vhost_scsi_nexus\n");
-		return -ENOMEM;
-	}
-	/*
-	 *  Initialize the struct se_session pointer and setup tagpool
-	 *  for struct vhost_scsi_cmd descriptors
-	 */
-	tv_nexus->tvn_se_sess = transport_init_session_tags(
-					VHOST_SCSI_DEFAULT_TAGS,
-					sizeof(struct vhost_scsi_cmd),
-					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
-	if (IS_ERR(tv_nexus->tvn_se_sess)) {
-		mutex_unlock(&tpg->tv_tpg_mutex);
-		kfree(tv_nexus);
-		return -ENOMEM;
-	}
-	se_sess = tv_nexus->tvn_se_sess;
 	for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
 		tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
 
 		tv_cmd->tvc_sgl = kzalloc(sizeof(struct scatterlist) *
 					VHOST_SCSI_PREALLOC_SGLS, GFP_KERNEL);
 		if (!tv_cmd->tvc_sgl) {
-			mutex_unlock(&tpg->tv_tpg_mutex);
 			pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
 			goto out;
 		}
 
 		tv_cmd->tvc_upages = kzalloc(sizeof(struct page *) *
-					VHOST_SCSI_PREALLOC_UPAGES, GFP_KERNEL);
+				VHOST_SCSI_PREALLOC_UPAGES, GFP_KERNEL);
 		if (!tv_cmd->tvc_upages) {
-			mutex_unlock(&tpg->tv_tpg_mutex);
 			pr_err("Unable to allocate tv_cmd->tvc_upages\n");
 			goto out;
 		}
 
 		tv_cmd->tvc_prot_sgl = kzalloc(sizeof(struct scatterlist) *
-					VHOST_SCSI_PREALLOC_PROT_SGLS, GFP_KERNEL);
+				VHOST_SCSI_PREALLOC_PROT_SGLS, GFP_KERNEL);
 		if (!tv_cmd->tvc_prot_sgl) {
-			mutex_unlock(&tpg->tv_tpg_mutex);
 			pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n");
 			goto out;
 		}
 	}
+	return 0;
+out:
+	vhost_scsi_free_cmd_map_res(se_sess);
+	return -ENOMEM;
+}
+
+static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
+				const char *name)
+{
+	struct se_portal_group *se_tpg;
+	struct vhost_scsi_nexus *tv_nexus;
+
+	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;
+	}
+	se_tpg = &tpg->se_tpg;
+
+	tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
+	if (!tv_nexus) {
+		mutex_unlock(&tpg->tv_tpg_mutex);
+		pr_err("Unable to allocate struct vhost_scsi_nexus\n");
+		return -ENOMEM;
+	}
 	/*
 	 * Since we are running in 'demo mode' this call with generate a
 	 * struct se_node_acl for the vhost_scsi 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) {
+	tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg,
+					VHOST_SCSI_DEFAULT_TAGS,
+					sizeof(struct vhost_scsi_cmd),
+					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
+					(unsigned char *)name, tv_nexus,
+					vhost_scsi_nexus_cb);
+	if (IS_ERR(tv_nexus->tvn_se_sess)) {
 		mutex_unlock(&tpg->tv_tpg_mutex);
-		pr_debug("core_tpg_check_initiator_node_acl() failed"
-				" for %s\n", name);
-		goto out;
+		kfree(tv_nexus);
+		return -ENOMEM;
 	}
-	/*
-	 * 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->tv_tpg_mutex);
 	return 0;
-
-out:
-	vhost_scsi_free_cmd_map_res(tv_nexus, se_sess);
-	transport_free_session(se_sess);
-	kfree(tv_nexus);
-	return -ENOMEM;
 }
 
 static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
@@ -1853,7 +1836,7 @@ static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
 		" %s Initiator Port: %s\n", vhost_scsi_dump_proto_id(tpg->tport),
 		tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
 
-	vhost_scsi_free_cmd_map_res(tv_nexus, se_sess);
+	vhost_scsi_free_cmd_map_res(se_sess);
 	/*
 	 * Release the SCSI I_T Nexus to the emulated vhost Target Port
 	 */
-- 
1.9.1

[PATCH-for-4.6 4/6] tcm_qla2xxx: Convert to target_alloc_session usage

[Nicholas A. Bellinger]

From: Nicholas Bellinger <nab@linux-iscsi.org>

Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>
Cc: Quinn Tran <quinn.tran@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/scsi/qla2xxx/qla_target.c  |  8 +---
 drivers/scsi/qla2xxx/qla_target.h  |  2 +-
 drivers/scsi/qla2xxx/tcm_qla2xxx.c | 79 +++++++++++++++++++-------------------
 3 files changed, 43 insertions(+), 46 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c
index c7ab9e6..80ae367 100644
--- a/drivers/scsi/qla2xxx/qla_target.c
+++ b/drivers/scsi/qla2xxx/qla_target.c
@@ -879,7 +879,6 @@ static struct qla_tgt_sess *qlt_create_sess(
 	struct qla_hw_data *ha = vha->hw;
 	struct qla_tgt_sess *sess;
 	unsigned long flags;
-	unsigned char be_sid[3];
 
 	/* Check to avoid double sessions */
 	spin_lock_irqsave(&ha->tgt.sess_lock, flags);
@@ -948,17 +947,14 @@ static struct qla_tgt_sess *qlt_create_sess(
 	    "Adding sess %p to tgt %p via ->check_initiator_node_acl()\n",
 	    sess, vha->vha_tgt.qla_tgt);
 
-	be_sid[0] = sess->s_id.b.domain;
-	be_sid[1] = sess->s_id.b.area;
-	be_sid[2] = sess->s_id.b.al_pa;
 	/*
 	 * Determine if this fc_port->port_name is allowed to access
 	 * target mode using explict NodeACLs+MappedLUNs, or using
 	 * TPG demo mode.  If this is successful a target mode FC nexus
 	 * is created.
 	 */
-	if (ha->tgt.tgt_ops->check_initiator_node_acl(vha,
-	    &fcport->port_name[0], sess, &be_sid[0], fcport->loop_id) < 0) {
+	if (ha->tgt.tgt_ops->check_initiator_node_acl(vha, &fcport->port_name[0],
+						      sess)) {
 		kfree(sess);
 		return NULL;
 	}
diff --git a/drivers/scsi/qla2xxx/qla_target.h b/drivers/scsi/qla2xxx/qla_target.h
index 71b2865..409bd5f 100644
--- a/drivers/scsi/qla2xxx/qla_target.h
+++ b/drivers/scsi/qla2xxx/qla_target.h
@@ -731,7 +731,7 @@ struct qla_tgt_func_tmpl {
 	void (*free_session)(struct qla_tgt_sess *);
 
 	int (*check_initiator_node_acl)(struct scsi_qla_host *, unsigned char *,
-					void *, uint8_t *, uint16_t);
+					struct qla_tgt_sess *);
 	void (*update_sess)(struct qla_tgt_sess *, port_id_t, uint16_t, bool);
 	struct qla_tgt_sess *(*find_sess_by_loop_id)(struct scsi_qla_host *,
 						const uint16_t);
diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
index b44f397..bf73c6f 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
@@ -1336,6 +1336,39 @@ static void tcm_qla2xxx_free_session(struct qla_tgt_sess *sess)
 	transport_deregister_session(sess->se_sess);
 }
 
+static int tcm_qla2xxx_session_cb(struct se_portal_group *se_tpg,
+				  struct se_session *se_sess, void *p)
+{
+	struct tcm_qla2xxx_tpg *tpg = container_of(se_tpg,
+				struct tcm_qla2xxx_tpg, se_tpg);
+	struct tcm_qla2xxx_lport *lport = tpg->lport;
+	struct qla_hw_data *ha = lport->qla_vha->hw;
+	struct se_node_acl *se_nacl = se_sess->se_node_acl;
+	struct tcm_qla2xxx_nacl *nacl = container_of(se_nacl,
+				struct tcm_qla2xxx_nacl, se_node_acl);
+	struct qla_tgt_sess *qlat_sess = p;
+	uint16_t loop_id = qlat_sess->loop_id;
+	unsigned long flags;
+	unsigned char be_sid[3];
+
+	be_sid[0] = qlat_sess->s_id.b.domain;
+	be_sid[1] = qlat_sess->s_id.b.area;
+	be_sid[2] = qlat_sess->s_id.b.al_pa;
+
+	/*
+	 * And now setup se_nacl and session pointers into HW lport internal
+	 * mappings for fabric S_ID and LOOP_ID.
+	 */
+	spin_lock_irqsave(&ha->tgt.sess_lock, flags);
+	tcm_qla2xxx_set_sess_by_s_id(lport, se_nacl, nacl,
+				     se_sess, qlat_sess, be_sid);
+	tcm_qla2xxx_set_sess_by_loop_id(lport, se_nacl, nacl,
+					se_sess, qlat_sess, loop_id);
+	spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
+
+	return 0;
+}
+
 /*
  * Called via qlt_create_sess():ha->qla2x_tmpl->check_initiator_node_acl()
  * to locate struct se_node_acl
@@ -1343,20 +1376,13 @@ static void tcm_qla2xxx_free_session(struct qla_tgt_sess *sess)
 static int tcm_qla2xxx_check_initiator_node_acl(
 	scsi_qla_host_t *vha,
 	unsigned char *fc_wwpn,
-	void *qla_tgt_sess,
-	uint8_t *s_id,
-	uint16_t loop_id)
+	struct qla_tgt_sess *qlat_sess)
 {
 	struct qla_hw_data *ha = vha->hw;
 	struct tcm_qla2xxx_lport *lport;
 	struct tcm_qla2xxx_tpg *tpg;
-	struct tcm_qla2xxx_nacl *nacl;
-	struct se_portal_group *se_tpg;
-	struct se_node_acl *se_nacl;
 	struct se_session *se_sess;
-	struct qla_tgt_sess *sess = qla_tgt_sess;
 	unsigned char port_name[36];
-	unsigned long flags;
 	int num_tags = (ha->cur_fw_xcb_count) ? ha->cur_fw_xcb_count :
 		       TCM_QLA2XXX_DEFAULT_TAGS;
 
@@ -1374,15 +1400,6 @@ static int tcm_qla2xxx_check_initiator_node_acl(
 		pr_err("Unable to lcoate struct tcm_qla2xxx_lport->tpg_1\n");
 		return -EINVAL;
 	}
-	se_tpg = &tpg->se_tpg;
-
-	se_sess = transport_init_session_tags(num_tags,
-					      sizeof(struct qla_tgt_cmd),
-					      TARGET_PROT_ALL);
-	if (IS_ERR(se_sess)) {
-		pr_err("Unable to initialize struct se_session\n");
-		return PTR_ERR(se_sess);
-	}
 	/*
 	 * Format the FCP Initiator port_name into colon seperated values to
 	 * match the format by tcm_qla2xxx explict ConfigFS NodeACLs.
@@ -1393,28 +1410,12 @@ static int tcm_qla2xxx_check_initiator_node_acl(
 	 * Locate our struct se_node_acl either from an explict NodeACL created
 	 * via ConfigFS, or via running in TPG demo mode.
 	 */
-	se_sess->se_node_acl = core_tpg_check_initiator_node_acl(se_tpg,
-					port_name);
-	if (!se_sess->se_node_acl) {
-		transport_free_session(se_sess);
-		return -EINVAL;
-	}
-	se_nacl = se_sess->se_node_acl;
-	nacl = container_of(se_nacl, struct tcm_qla2xxx_nacl, se_node_acl);
-	/*
-	 * And now setup the new se_nacl and session pointers into our HW lport
-	 * mappings for fabric S_ID and LOOP_ID.
-	 */
-	spin_lock_irqsave(&ha->tgt.sess_lock, flags);
-	tcm_qla2xxx_set_sess_by_s_id(lport, se_nacl, nacl, se_sess,
-			qla_tgt_sess, s_id);
-	tcm_qla2xxx_set_sess_by_loop_id(lport, se_nacl, nacl, se_sess,
-			qla_tgt_sess, loop_id);
-	spin_unlock_irqrestore(&ha->tgt.sess_lock, flags);
-	/*
-	 * Finally register the new FC Nexus with TCM
-	 */
-	transport_register_session(se_nacl->se_tpg, se_nacl, se_sess, sess);
+	se_sess = target_alloc_session(&tpg->se_tpg, num_tags,
+				       sizeof(struct qla_tgt_cmd),
+				       TARGET_PROT_ALL, port_name,
+				       qlat_sess, tcm_qla2xxx_session_cb);
+	if (IS_ERR(se_sess))
+		return PTR_ERR(se_sess);
 
 	return 0;
 }
-- 
1.9.1

[PATCH-for-4.6 5/6] tcm_fc: Convert to target_alloc_session usage

[Nicholas A. Bellinger]

From: Nicholas Bellinger <nab@linux-iscsi.org>

Cc: Vasu Dev <vasu.dev@linux.intel.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/tcm_fc/tfc_sess.c | 47 +++++++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 22 deletions(-)

diff --git a/drivers/target/tcm_fc/tfc_sess.c b/drivers/target/tcm_fc/tfc_sess.c
index b3db638..19bfbda 100644
--- a/drivers/target/tcm_fc/tfc_sess.c
+++ b/drivers/target/tcm_fc/tfc_sess.c
@@ -186,6 +186,20 @@ out:
 	return NULL;
 }
 
+static int ft_sess_alloc_cb(struct se_portal_group *se_tpg,
+			    struct se_session *se_sess, void *p)
+{
+	struct ft_sess *sess = p;
+	struct ft_tport *tport = sess->tport;
+	struct hlist_head *head = &tport->hash[ft_sess_hash(sess->port_id)];
+
+	pr_debug("port_id %x sess %p\n", sess->port_id, sess);
+	hlist_add_head_rcu(&sess->hash, head);
+	tport->sess_count++;
+
+	return 0;
+}
+
 /*
  * Allocate session and enter it in the hash for the local port.
  * Caller holds ft_lport_lock.
@@ -193,9 +207,10 @@ out:
 static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
 				      struct fc_rport_priv *rdata)
 {
+	struct se_portal_group *se_tpg = &tport->tpg->se_tpg;
 	struct ft_sess *sess;
-	struct ft_node_acl *acl;
 	struct hlist_head *head;
+	unsigned char iname[TRANSPORT_IQN_LEN];
 
 	head = &tport->hash[ft_sess_hash(port_id)];
 	hlist_for_each_entry_rcu(sess, head, hash)
@@ -206,32 +221,20 @@ static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
 	if (!sess)
 		return NULL;
 
-	sess->se_sess = transport_init_session_tags(TCM_FC_DEFAULT_TAGS,
-						    sizeof(struct ft_cmd),
-						    TARGET_PROT_NORMAL);
-	if (IS_ERR(sess->se_sess)) {
-		kfree(sess);
-		return NULL;
-	}
+	kref_init(&sess->kref); /* ref for table entry */
+	sess->tport = tport;
+	sess->port_id = port_id;
+	ft_format_wwn(&iname[0], TRANSPORT_IQN_LEN, rdata->ids.port_name);
 
-	acl = ft_acl_get(tport->tpg, rdata);
-	if (!acl) {
-		transport_free_session(sess->se_sess);
+	sess->se_sess = target_alloc_session(se_tpg, TCM_FC_DEFAULT_TAGS,
+					     sizeof(struct ft_cmd),
+					     TARGET_PROT_NORMAL, &iname[0],
+					     sess, ft_sess_alloc_cb);
+	if (IS_ERR(sess->se_sess)) {
 		kfree(sess);
 		return NULL;
 	}
 
-	sess->se_sess->se_node_acl = &acl->se_node_acl;
-	sess->tport = tport;
-	sess->port_id = port_id;
-	kref_init(&sess->kref);	/* ref for table entry */
-	hlist_add_head_rcu(&sess->hash, head);
-	tport->sess_count++;
-
-	pr_debug("port_id %x sess %p\n", port_id, sess);
-
-	transport_register_session(&tport->tpg->se_tpg, &acl->se_node_acl,
-				   sess->se_sess, sess);
 	return sess;
 }
 
-- 
1.9.1

[PATCH-for-4.6 6/6] ib_srpt: Convert to target_alloc_session usage

[Nicholas A. Bellinger]

From: Nicholas Bellinger <nab@linux-iscsi.org>

Cc: Vu Pham <vu@mellanox.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/infiniband/ulp/srpt/ib_srpt.c | 23 ++++++-----------------
 1 file changed, 6 insertions(+), 17 deletions(-)

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
index 2ef6466..44878a3 100644
--- a/drivers/infiniband/ulp/srpt/ib_srpt.c
+++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
@@ -2387,7 +2387,6 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
 	struct srp_login_rej *rej;
 	struct ib_cm_rep_param *rep_param;
 	struct srpt_rdma_ch *ch, *tmp_ch;
-	struct se_node_acl *se_acl;
 	u32 it_iu_len;
 	int i, ret = 0;
 	unsigned char *p;
@@ -2553,19 +2552,12 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
 	pr_debug("registering session %s\n", ch->sess_name);
 	p = &ch->sess_name[0];
 
-	ch->sess = transport_init_session(TARGET_PROT_NORMAL);
-	if (IS_ERR(ch->sess)) {
-		rej->reason = cpu_to_be32(
-				SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
-		pr_debug("Failed to create session\n");
-		goto destroy_ib;
-	}
-
 try_again:
-	se_acl = core_tpg_get_initiator_node_acl(&sport->port_tpg_1, p);
-	if (!se_acl) {
+	ch->sess = target_alloc_session(&sport->port_tpg_1, 0, 0,
+					TARGET_PROT_NORMAL, p, ch, NULL);
+	if (IS_ERR(ch->sess)) {
 		pr_info("Rejected login because no ACL has been"
-			" configured yet for initiator %s.\n", ch->sess_name);
+			" configured yet for initiator %s.\n", p);
 		/*
 		 * XXX: Hack to retry of ch->i_port_id without leading '0x'
 		 */
@@ -2573,14 +2565,11 @@ try_again:
 			p += 2;
 			goto try_again;
 		}
-		rej->reason = cpu_to_be32(
+		rej->reason = cpu_to_be32((PTR_ERR(ch->sess) == -ENOMEM) ?
+				SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES :
 				SRP_LOGIN_REJ_CHANNEL_LIMIT_REACHED);
-		transport_free_session(ch->sess);
 		goto destroy_ib;
 	}
-	ch->sess->se_node_acl = se_acl;
-
-	transport_register_session(&sport->port_tpg_1, se_acl, ch->sess, ch);
 
 	pr_debug("Establish connection sess=%p name=%s cm_id=%p\n", ch->sess,
 		 ch->sess_name, ch->cm_id);
-- 
1.9.1

Re: [PATCH-for-4.6 3/6] vhost/scsi: Convert to target_alloc_session usage

[Michael S. Tsirkin]

On Sun, Jan 10, 2016 at 08:44:25PM +0000, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
> 
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

Pls merge this patch yourself to avoid dependency issues.

> ---
>  drivers/vhost/scsi.c | 99 ++++++++++++++++++++++------------------------------
>  1 file changed, 41 insertions(+), 58 deletions(-)
> 
> diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
> index 29cfc57..cd5f20f 100644
> --- a/drivers/vhost/scsi.c
> +++ b/drivers/vhost/scsi.c
> @@ -1664,8 +1664,7 @@ static void vhost_scsi_port_unlink(struct se_portal_group *se_tpg,
>  	mutex_unlock(&vhost_scsi_mutex);
>  }
>  
> -static void vhost_scsi_free_cmd_map_res(struct vhost_scsi_nexus *nexus,
> -				       struct se_session *se_sess)
> +static void vhost_scsi_free_cmd_map_res(struct se_session *se_sess)
>  {
>  	struct vhost_scsi_cmd *tv_cmd;
>  	unsigned int i;
> @@ -1721,98 +1720,82 @@ static struct configfs_attribute *vhost_scsi_tpg_attrib_attrs[] = {
>  	NULL,
>  };
>  
> -static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
> -				const char *name)
> +static int vhost_scsi_nexus_cb(struct se_portal_group *se_tpg,
> +			       struct se_session *se_sess, void *p)
>  {
> -	struct se_portal_group *se_tpg;
> -	struct se_session *se_sess;
> -	struct vhost_scsi_nexus *tv_nexus;
>  	struct vhost_scsi_cmd *tv_cmd;
>  	unsigned int i;
>  
> -	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;
> -	}
> -	se_tpg = &tpg->se_tpg;
> -
> -	tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
> -	if (!tv_nexus) {
> -		mutex_unlock(&tpg->tv_tpg_mutex);
> -		pr_err("Unable to allocate struct vhost_scsi_nexus\n");
> -		return -ENOMEM;
> -	}
> -	/*
> -	 *  Initialize the struct se_session pointer and setup tagpool
> -	 *  for struct vhost_scsi_cmd descriptors
> -	 */
> -	tv_nexus->tvn_se_sess = transport_init_session_tags(
> -					VHOST_SCSI_DEFAULT_TAGS,
> -					sizeof(struct vhost_scsi_cmd),
> -					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS);
> -	if (IS_ERR(tv_nexus->tvn_se_sess)) {
> -		mutex_unlock(&tpg->tv_tpg_mutex);
> -		kfree(tv_nexus);
> -		return -ENOMEM;
> -	}
> -	se_sess = tv_nexus->tvn_se_sess;
>  	for (i = 0; i < VHOST_SCSI_DEFAULT_TAGS; i++) {
>  		tv_cmd = &((struct vhost_scsi_cmd *)se_sess->sess_cmd_map)[i];
>  
>  		tv_cmd->tvc_sgl = kzalloc(sizeof(struct scatterlist) *
>  					VHOST_SCSI_PREALLOC_SGLS, GFP_KERNEL);
>  		if (!tv_cmd->tvc_sgl) {
> -			mutex_unlock(&tpg->tv_tpg_mutex);
>  			pr_err("Unable to allocate tv_cmd->tvc_sgl\n");
>  			goto out;
>  		}
>  
>  		tv_cmd->tvc_upages = kzalloc(sizeof(struct page *) *
> -					VHOST_SCSI_PREALLOC_UPAGES, GFP_KERNEL);
> +				VHOST_SCSI_PREALLOC_UPAGES, GFP_KERNEL);
>  		if (!tv_cmd->tvc_upages) {
> -			mutex_unlock(&tpg->tv_tpg_mutex);
>  			pr_err("Unable to allocate tv_cmd->tvc_upages\n");
>  			goto out;
>  		}
>  
>  		tv_cmd->tvc_prot_sgl = kzalloc(sizeof(struct scatterlist) *
> -					VHOST_SCSI_PREALLOC_PROT_SGLS, GFP_KERNEL);
> +				VHOST_SCSI_PREALLOC_PROT_SGLS, GFP_KERNEL);
>  		if (!tv_cmd->tvc_prot_sgl) {
> -			mutex_unlock(&tpg->tv_tpg_mutex);
>  			pr_err("Unable to allocate tv_cmd->tvc_prot_sgl\n");
>  			goto out;
>  		}
>  	}
> +	return 0;
> +out:
> +	vhost_scsi_free_cmd_map_res(se_sess);
> +	return -ENOMEM;
> +}
> +
> +static int vhost_scsi_make_nexus(struct vhost_scsi_tpg *tpg,
> +				const char *name)
> +{
> +	struct se_portal_group *se_tpg;
> +	struct vhost_scsi_nexus *tv_nexus;
> +
> +	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;
> +	}
> +	se_tpg = &tpg->se_tpg;
> +
> +	tv_nexus = kzalloc(sizeof(struct vhost_scsi_nexus), GFP_KERNEL);
> +	if (!tv_nexus) {
> +		mutex_unlock(&tpg->tv_tpg_mutex);
> +		pr_err("Unable to allocate struct vhost_scsi_nexus\n");
> +		return -ENOMEM;
> +	}
>  	/*
>  	 * Since we are running in 'demo mode' this call with generate a
>  	 * struct se_node_acl for the vhost_scsi 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) {
> +	tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg,
> +					VHOST_SCSI_DEFAULT_TAGS,
> +					sizeof(struct vhost_scsi_cmd),
> +					TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS,
> +					(unsigned char *)name, tv_nexus,
> +					vhost_scsi_nexus_cb);
> +	if (IS_ERR(tv_nexus->tvn_se_sess)) {
>  		mutex_unlock(&tpg->tv_tpg_mutex);
> -		pr_debug("core_tpg_check_initiator_node_acl() failed"
> -				" for %s\n", name);
> -		goto out;
> +		kfree(tv_nexus);
> +		return -ENOMEM;
>  	}
> -	/*
> -	 * 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->tv_tpg_mutex);
>  	return 0;
> -
> -out:
> -	vhost_scsi_free_cmd_map_res(tv_nexus, se_sess);
> -	transport_free_session(se_sess);
> -	kfree(tv_nexus);
> -	return -ENOMEM;
>  }
>  
>  static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
> @@ -1853,7 +1836,7 @@ static int vhost_scsi_drop_nexus(struct vhost_scsi_tpg *tpg)
>  		" %s Initiator Port: %s\n", vhost_scsi_dump_proto_id(tpg->tport),
>  		tv_nexus->tvn_se_sess->se_node_acl->initiatorname);
>  
> -	vhost_scsi_free_cmd_map_res(tv_nexus, se_sess);
> +	vhost_scsi_free_cmd_map_res(se_sess);
>  	/*
>  	 * Release the SCSI I_T Nexus to the emulated vhost Target Port
>  	 */
> -- 
> 1.9.1

Re: [PATCH-for-4.6 1/6] target: Add target_alloc_session() helper function

[Bart Van Assche]

On 01/10/2016 12:44 PM, Nicholas A. Bellinger wrote:
> From: Nicholas Bellinger <nab@linux-iscsi.org>
>
> Based on HCH's original patch, this adds a full version to
> support percpu-ida tag pre-allocation and callback function
> pointer into fabric driver code to complete session setup.
>
> Reported-by: Christoph Hellwig <hch@lst.de>
> Cc: Sagi Grimberg <sagig@mellanox.com>
> Cc: Christoph Hellwig <hch@lst.de>
> Cc: Hannes Reinecke <hare@suse.de>
> Cc: Andy Grover <agrover@redhat.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> ---
>   drivers/target/target_core_transport.c | 55 ++++++++++++++++++++++++++++++++++
>   include/target/target_core_fabric.h    |  6 ++++
>   2 files changed, 61 insertions(+)
>
> diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
> index c5035b9..fd4404f6 100644
> --- a/drivers/target/target_core_transport.c
> +++ b/drivers/target/target_core_transport.c
> @@ -374,6 +374,61 @@ void transport_register_session(
>   }
>   EXPORT_SYMBOL(transport_register_session);
>
> +struct se_session *
> +target_alloc_session(struct se_portal_group *tpg,
> +		     unsigned int tag_num, unsigned int tag_size,
> +		     enum target_prot_op prot_op,
> +		     const char *initiatorname, void *private,
> +		     int (*callback)(struct se_portal_group *,
> +				     struct se_session *, void *))

Please use a more descriptive name instead of "callback", e.g. 
"init_session".

> +{
> +	struct se_session *sess;
> +
> +	if (tag_num != 0 && !tag_size) {
> +		pr_err("target_alloc_session called with percpu-ida tag_num:"
> +		       " %u, but zero tag_size\n", tag_num);
> +		return ERR_PTR(-EINVAL);
> +	}
> +	if (!tag_num && tag_size) {
> +		pr_err("target_alloc_session called with percpu-ida tag_size:"
> +		       " %u, but zero tag_num\n", tag_size);
> +		return ERR_PTR(-EINVAL);
> +	}

Please combine the above two tests into a single test, e.g. !!tag_num != 
!!tag_size or (bool)tag_num != (bool)tag_size.

Thanks,

Bart.

Re: [PATCH-for-4.6 1/6] target: Add target_alloc_session() helper function

[Christoph Hellwig]

> +struct se_session *
> +target_alloc_session(struct se_portal_group *tpg,
> +		     unsigned int tag_num, unsigned int tag_size,
> +		     enum target_prot_op prot_op,
> +		     const char *initiatorname, void *private,
> +		     int (*callback)(struct se_portal_group *,
> +				     struct se_session *, void *))
> +{

I'd much rather have the fabrics drivers call transport_alloc_session_tags
directly from the callback than growing even more arguments here.

> +	struct se_session *sess;
> +
> +	if (tag_num != 0 && !tag_size) {
> +		pr_err("target_alloc_session called with percpu-ida tag_num:"
> +		       " %u, but zero tag_size\n", tag_num);
> +		return ERR_PTR(-EINVAL);
> +	}
> +	if (!tag_num && tag_size) {
> +		pr_err("target_alloc_session called with percpu-ida tag_size:"
> +		       " %u, but zero tag_num\n", tag_size);
> +		return ERR_PTR(-EINVAL);
> +	}

These checks should be in transport_alloc_session_tags.

Re: [PATCH-for-4.6 1/6] target: Add target_alloc_session() helper function

[Nicholas A. Bellinger]

On Tue, 2016-01-12 at 16:11 +0100, Christoph Hellwig wrote:
> > +struct se_session *
> > +target_alloc_session(struct se_portal_group *tpg,
> > +		     unsigned int tag_num, unsigned int tag_size,
> > +		     enum target_prot_op prot_op,
> > +		     const char *initiatorname, void *private,
> > +		     int (*callback)(struct se_portal_group *,
> > +				     struct se_session *, void *))
> > +{
> 
> I'd much rather have the fabrics drivers call transport_alloc_session_tags
> directly from the callback than growing even more arguments here.
> 

What's the point..?

Only vhost-scsi currently needs to allocate extra resources for
se_session percpu-ida tag pre-allocation.

The rest of the consumers can just use this common code.

> > +	struct se_session *sess;
> > +
> > +	if (tag_num != 0 && !tag_size) {
> > +		pr_err("target_alloc_session called with percpu-ida tag_num:"
> > +		       " %u, but zero tag_size\n", tag_num);
> > +		return ERR_PTR(-EINVAL);
> > +	}
> > +	if (!tag_num && tag_size) {
> > +		pr_err("target_alloc_session called with percpu-ida tag_size:"
> > +		       " %u, but zero tag_num\n", tag_size);
> > +		return ERR_PTR(-EINVAL);
> > +	}
> 
> These checks should be in transport_alloc_session_tags.
> 

Done.

Re: [PATCH-for-4.6 1/6] target: Add target_alloc_session() helper function

[Christoph Hellwig]

On Wed, Jan 13, 2016 at 12:09:26AM -0800, Nicholas A. Bellinger wrote:
> > I'd much rather have the fabrics drivers call transport_alloc_session_tags
> > directly from the callback than growing even more arguments here.
> > 
> 
> What's the point..?
> 
> Only vhost-scsi currently needs to allocate extra resources for
> se_session percpu-ida tag pre-allocation.

The point is that allocating "tags" (or better command structures) isn't
fundamentally related to allocating a session, and in fact not even
used by many drivers.  A flow where drivers that need these "tags"
explicitly allocate them is a lot more obvious than forcing more
arguments to a function that already has a lot and isn't related to
these "tags" otherwise.

Re: [PATCH-for-4.6 1/6] target: Add target_alloc_session() helper function

[Nicholas A. Bellinger]

On Wed, 2016-01-13 at 09:17 +0100, Christoph Hellwig wrote:
> On Wed, Jan 13, 2016 at 12:09:26AM -0800, Nicholas A. Bellinger wrote:
> > > I'd much rather have the fabrics drivers call transport_alloc_session_tags
> > > directly from the callback than growing even more arguments here.
> > > 
> > 
> > What's the point..?
> > 
> > Only vhost-scsi currently needs to allocate extra resources for
> > se_session percpu-ida tag pre-allocation.
> 
> The point is that allocating "tags" (or better command structures) isn't
> fundamentally related to allocating a session, and in fact not even
> used by many drivers.

Huh..?  It's used by iscsi-target, ib_isert, tcm_qla2xxx, vhost-scsi and
tcm_fc.

That's the majority of the drivers people care about.

>  A flow where drivers that need these "tags"
> explicitly allocate them is a lot more obvious than forcing more
> arguments to a function that already has a lot and isn't related to
> these "tags" otherwise.

The goal is to get to the point where all fabric drivers use tag
pre-allocation, and not vice-versa.

That said, I think it makes sense to leave it as is instead of adding
new callbacks for iscsi-target, ib_isert, and tcm_fc to just handle
se_session tag pre-allocation.

Re: [PATCH-for-4.6 1/6] target: Add target_alloc_session() helper function

[Christoph Hellwig]

On Wed, Jan 13, 2016 at 01:22:49AM -0800, Nicholas A. Bellinger wrote:
> Huh..?  It's used by iscsi-target, ib_isert, tcm_qla2xxx, vhost-scsi and
> tcm_fc.
> 
> That's the majority of the drivers people care about.

ib_isert never calls transport_init_session / transport_init_session_tags
directly.

We've got 3 callers to transport_init_session_tags vs 6 to
transport_init_session.

iSCSI already works roughly the way I suggest everything should
work in the future - it uses transport_init_session but manually
allocates the tags.

Re: [PATCH-for-4.6 1/6] target: Add target_alloc_session() helper function

[Nicholas A. Bellinger]

On Wed, 2016-01-13 at 10:33 +0100, Christoph Hellwig wrote:
> On Wed, Jan 13, 2016 at 01:22:49AM -0800, Nicholas A. Bellinger wrote:
> > Huh..?  It's used by iscsi-target, ib_isert, tcm_qla2xxx, vhost-scsi and
> > tcm_fc.
> > 
> > That's the majority of the drivers people care about.
> 
> ib_isert never calls transport_init_session / transport_init_session_tags
> directly.
> 

Yes.

Not to mention, there is a new struct iscsit_transport based driver on
the way that assumes percpu-ida tag preallocation using this same
method.

> We've got 3 callers to transport_init_session_tags vs 6 to
> transport_init_session.
> 

In that case, I'll look into converting sbp-target, usb-gadget and
xen-scsiback to use percpu-ida like the other consumers here for v4.6
code. 

> iSCSI already works roughly the way I suggest everything should
> work in the future - it uses transport_init_session but manually
> allocates the tags.

iscsi-target needs it open-coded for discovery purposes, because
se_node_acl lookup does not occur.

However for the normal session login se_node_acl lookup back, I don't
see a reason why iscsi-target can't use target_alloc_session() here too.