[PATCH-v2 0/4] iscsi-target: Add support for login multi-plexing support

[PATCH-v2 0/4] iscsi-target: Add support for login multi-plexing support

[Nicholas A. Bellinger]

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

Hi folks,

This -v2 series for v3.12-rc1 adds support for login multi-plexing,
that allows subsequent login request/request PDUs beyond the initial 
exchange to be pushed off to workqueue process context, so that other
incoming login requests can be serviced in parallel.

This addresses a long-standing issue with login latency with many (100's)
of parallel login requests to the same network portal being shared
across many (100's) of TargetName+TargetPortalGroup endpoints.

Note that login negotiation to the same TargetName+TargetPortalGroup
endpoint is still sychronized in order to enforce session reinstatement
state machines.

The changes for v2 include:

  - Fix iscsit_transport reference leak during NP thread reset
  - Remove duplicate call to iscsi_post_login_handler() in
    __iscsi_target_login_thread()
  - Drop unused iscsi_np->np_login_tpg
  - Add login_timer in iscsi_target_do_login_rx() to avoid
    possible endless sleep with MSG_WAITALL for traditional
    iscsi-target in certain network configurations.
  - Convert lprintk() -> pr_debug()
  - Remove forward declarations of iscsi_target_set_sock_callbacks(),
    iscsi_target_restore_sock_callbacks() and iscsi_target_sk_data_ready()
  - Make iscsi_target_set_sock_callbacks + iscsi_target_restore_sock_callbacks()
    static (Fengguang)
  - Make iscsi_target_do_login_rx() safe for iser-target w/o conn->sock
  - Updates to iser-target for login negotiation multi-plexing support

The main remaining FIXME is to keep track of connections that are pushed
out to workqueue process context for explicit network portal shutdown
purposes.

Thanks!

--nab

Nicholas Bellinger (4):
  iscsi-target: Fix iscsit_transport reference leak during NP thread
    reset
  iscsi-target: Prepare login code for multi-plexing support
  iscsi-target: Add login negotiation multi-plexing support
  iser-target: Updates for login negotiation multi-plexing support

 drivers/infiniband/ulp/isert/ib_isert.c   |   17 +++-
 drivers/target/iscsi/iscsi_target.c       |   53 ++++----
 drivers/target/iscsi/iscsi_target.h       |    6 +-
 drivers/target/iscsi/iscsi_target_core.h  |   12 ++-
 drivers/target/iscsi/iscsi_target_login.c |  171 +++++++++++++----------
 drivers/target/iscsi/iscsi_target_login.h |    3 +
 drivers/target/iscsi/iscsi_target_nego.c  |  209 +++++++++++++++++++++++++++-
 drivers/target/iscsi/iscsi_target_tpg.c   |   23 +++-
 drivers/target/iscsi/iscsi_target_tpg.h   |    4 +-
 9 files changed, 378 insertions(+), 120 deletions(-)

-- 
1.7.2.5

[PATCH-v2 1/4] iscsi-target: Fix iscsit_transport reference leak during NP thread reset

[Nicholas A. Bellinger]

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

This patch fixes a bug in __iscsi_target_login_thread() where an explicit
network portal thread reset ends up leaking the iscsit_transport module
reference, along with the associated iscsi_conn allocation.

This manifests itself with iser-target where a NP reset causes the extra
iscsit_transport reference to be taken in iscsit_conn_set_transport()
during the reset, which prevents the ib_isert module from being unloaded
after the NP thread shutdown has finished.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/iscsi/iscsi_target_login.c |    9 ++++-----
 1 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 0e85238..4c17f83 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -1171,12 +1171,11 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
 		if (np->np_thread_state == ISCSI_NP_THREAD_RESET) {
 			spin_unlock_bh(&np->np_thread_lock);
 			complete(&np->np_restart_comp);
-			if (ret == -ENODEV) {
-				iscsit_put_transport(conn->conn_transport);
-				kfree(conn);
-				conn = NULL;
+			iscsit_put_transport(conn->conn_transport);
+			kfree(conn);
+			conn = NULL;
+			if (ret == -ENODEV)
 				goto out;
-			}
 			/* Get another socket */
 			return 1;
 		}
-- 
1.7.2.5

[PATCH-v2 2/4] iscsi-target: Prepare login code for multi-plexing support

[Nicholas A. Bellinger]

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

This patch prepares the iscsi-target login code for multi-plexing
support.  This includes:

 - Adding iscsi_tpg_np->tpg_np_kref + iscsit_login_kref_put() for
   handling callback of iscsi_tpg_np->tpg_np_comp
 - Adding kref_put() in iscsit_deaccess_np()
 - Adding kref_put() and wait_for_completion() in
   iscsit_reset_np_thread()
 - Refactor login failure path release logic into
   iscsi_target_login_sess_out()
 - Update __iscsi_target_login_thread() to handle
   iscsi_post_login_handler() asynchronous completion
 - Add shutdown parameter for iscsit_clear_tpg_np_login_thread*()

v2 changes:
 - Remove duplicate call to iscsi_post_login_handler() in
   __iscsi_target_login_thread()
 - Drop unused iscsi_np->np_login_tpg

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/iscsi/iscsi_target.c       |   53 +++++-----
 drivers/target/iscsi/iscsi_target.h       |    6 +-
 drivers/target/iscsi/iscsi_target_core.h  |   11 ++-
 drivers/target/iscsi/iscsi_target_login.c |  162 +++++++++++++++++------------
 drivers/target/iscsi/iscsi_target_login.h |    3 +
 drivers/target/iscsi/iscsi_target_tpg.c   |   16 ++-
 drivers/target/iscsi/iscsi_target_tpg.h   |    2 +-
 7 files changed, 149 insertions(+), 104 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index c4aeac3..7228cc7 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -220,11 +220,6 @@ int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
 		spin_unlock_bh(&np->np_thread_lock);
 		return -1;
 	}
-	if (np->np_login_tpg) {
-		pr_err("np->np_login_tpg() is not NULL!\n");
-		spin_unlock_bh(&np->np_thread_lock);
-		return -1;
-	}
 	spin_unlock_bh(&np->np_thread_lock);
 	/*
 	 * Determine if the portal group is accepting storage traffic.
@@ -243,23 +238,35 @@ int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
 	if ((ret != 0) || signal_pending(current))
 		return -1;
 
-	spin_lock_bh(&np->np_thread_lock);
-	np->np_login_tpg = tpg;
-	spin_unlock_bh(&np->np_thread_lock);
+	spin_lock_bh(&tpg->tpg_state_lock);
+	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
+		spin_unlock_bh(&tpg->tpg_state_lock);
+		mutex_unlock(&tpg->np_login_lock);
+		return -1;
+	}
+	spin_unlock_bh(&tpg->tpg_state_lock);
 
 	return 0;
 }
 
-int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
+void iscsit_login_kref_put(struct kref *kref)
 {
-	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
+	struct iscsi_tpg_np *tpg_np = container_of(kref,
+				struct iscsi_tpg_np, tpg_np_kref);
 
-	spin_lock_bh(&np->np_thread_lock);
-	np->np_login_tpg = NULL;
-	spin_unlock_bh(&np->np_thread_lock);
+	complete(&tpg_np->tpg_np_comp);
+}
+
+int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg,
+		       struct iscsi_tpg_np *tpg_np)
+{
+	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
 
 	mutex_unlock(&tpg->np_login_lock);
 
+	if (tpg_np)
+		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
+
 	if (tiqn)
 		iscsit_put_tiqn_for_login(tiqn);
 
@@ -410,20 +417,10 @@ struct iscsi_np *iscsit_add_np(
 int iscsit_reset_np_thread(
 	struct iscsi_np *np,
 	struct iscsi_tpg_np *tpg_np,
-	struct iscsi_portal_group *tpg)
+	struct iscsi_portal_group *tpg,
+	bool shutdown)
 {
 	spin_lock_bh(&np->np_thread_lock);
-	if (tpg && tpg_np) {
-		/*
-		 * The reset operation need only be performed when the
-		 * passed struct iscsi_portal_group has a login in progress
-		 * to one of the network portals.
-		 */
-		if (tpg_np->tpg_np->np_login_tpg != tpg) {
-			spin_unlock_bh(&np->np_thread_lock);
-			return 0;
-		}
-	}
 	if (np->np_thread_state == ISCSI_NP_THREAD_INACTIVE) {
 		spin_unlock_bh(&np->np_thread_lock);
 		return 0;
@@ -438,6 +435,12 @@ int iscsit_reset_np_thread(
 	}
 	spin_unlock_bh(&np->np_thread_lock);
 
+	if (tpg_np && shutdown) {
+		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
+
+		wait_for_completion(&tpg_np->tpg_np_comp);
+	}
+
 	return 0;
 }
 
diff --git a/drivers/target/iscsi/iscsi_target.h b/drivers/target/iscsi/iscsi_target.h
index 2c437cb..f82f627 100644
--- a/drivers/target/iscsi/iscsi_target.h
+++ b/drivers/target/iscsi/iscsi_target.h
@@ -7,13 +7,15 @@ extern void iscsit_put_tiqn_for_login(struct iscsi_tiqn *);
 extern struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *);
 extern void iscsit_del_tiqn(struct iscsi_tiqn *);
 extern int iscsit_access_np(struct iscsi_np *, struct iscsi_portal_group *);
-extern int iscsit_deaccess_np(struct iscsi_np *, struct iscsi_portal_group *);
+extern void iscsit_login_kref_put(struct kref *);
+extern int iscsit_deaccess_np(struct iscsi_np *, struct iscsi_portal_group *,
+				struct iscsi_tpg_np *);
 extern bool iscsit_check_np_match(struct __kernel_sockaddr_storage *,
 				struct iscsi_np *, int);
 extern struct iscsi_np *iscsit_add_np(struct __kernel_sockaddr_storage *,
 				char *, int);
 extern int iscsit_reset_np_thread(struct iscsi_np *, struct iscsi_tpg_np *,
-				struct iscsi_portal_group *);
+				struct iscsi_portal_group *, bool);
 extern int iscsit_del_np(struct iscsi_np *);
 extern int iscsit_reject_cmd(struct iscsi_cmd *cmd, u8, unsigned char *);
 extern void iscsit_set_unsoliticed_dataout(struct iscsi_cmd *);
diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index 4f77a78..711a028 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -554,6 +554,11 @@ struct iscsi_conn {
 	struct completion	rx_half_close_comp;
 	/* socket used by this connection */
 	struct socket		*sock;
+	void			(*orig_data_ready)(struct sock *, int);
+#define LOGIN_FLAGS_READ_ACTIVE		1
+	unsigned long		login_flags;
+	struct delayed_work	login_work;
+	struct iscsi_login	*login;
 	struct timer_list	nopin_timer;
 	struct timer_list	nopin_response_timer;
 	struct timer_list	transport_timer;
@@ -584,6 +589,7 @@ struct iscsi_conn {
 	void			*context;
 	struct iscsi_login_thread_s *login_thread;
 	struct iscsi_portal_group *tpg;
+	struct iscsi_tpg_np	*tpg_np;
 	/* Pointer to parent session */
 	struct iscsi_session	*sess;
 	/* Pointer to thread_set in use for this conn's threads */
@@ -682,6 +688,7 @@ struct iscsi_login {
 	u8 version_max;
 	u8 login_complete;
 	u8 login_failed;
+	bool zero_tsih;
 	char isid[6];
 	u32 cmd_sn;
 	itt_t init_task_tag;
@@ -694,6 +701,7 @@ struct iscsi_login {
 	char *req_buf;
 	char *rsp_buf;
 	struct iscsi_conn *conn;
+	struct iscsi_np *np;
 } ____cacheline_aligned;
 
 struct iscsi_node_attrib {
@@ -773,7 +781,6 @@ struct iscsi_np {
 	struct __kernel_sockaddr_storage np_sockaddr;
 	struct task_struct	*np_thread;
 	struct timer_list	np_login_timer;
-	struct iscsi_portal_group *np_login_tpg;
 	void			*np_context;
 	struct iscsit_transport *np_transport;
 	struct list_head	np_list;
@@ -788,6 +795,8 @@ struct iscsi_tpg_np {
 	struct list_head	tpg_np_parent_list;
 	struct se_tpg_np	se_tpg_np;
 	spinlock_t		tpg_np_parent_lock;
+	struct completion	tpg_np_comp;
+	struct kref		tpg_np_kref;
 };
 
 struct iscsi_portal_group {
diff --git a/drivers/target/iscsi/iscsi_target_login.c b/drivers/target/iscsi/iscsi_target_login.c
index 4c17f83..c29fffd 100644
--- a/drivers/target/iscsi/iscsi_target_login.c
+++ b/drivers/target/iscsi/iscsi_target_login.c
@@ -50,6 +50,7 @@ static struct iscsi_login *iscsi_login_init_conn(struct iscsi_conn *conn)
 		pr_err("Unable to allocate memory for struct iscsi_login.\n");
 		return NULL;
 	}
+	conn->login = login;
 	login->conn = conn;
 	login->first_request = 1;
 
@@ -684,7 +685,7 @@ static void iscsi_post_login_start_timers(struct iscsi_conn *conn)
 		iscsit_start_nopin_timer(conn);
 }
 
-static int iscsi_post_login_handler(
+int iscsi_post_login_handler(
 	struct iscsi_np *np,
 	struct iscsi_conn *conn,
 	u8 zero_tsih)
@@ -1124,6 +1125,77 @@ iscsit_conn_set_transport(struct iscsi_conn *conn, struct iscsit_transport *t)
 	return 0;
 }
 
+void iscsi_target_login_sess_out(struct iscsi_conn *conn,
+		struct iscsi_np *np, bool zero_tsih, bool new_sess)
+{
+	if (new_sess == false)
+		goto old_sess_out;
+
+	pr_err("iSCSI Login negotiation failed.\n");
+	iscsit_collect_login_stats(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
+				   ISCSI_LOGIN_STATUS_INIT_ERR);
+	if (!zero_tsih || !conn->sess)
+		goto old_sess_out;
+	if (conn->sess->se_sess)
+		transport_free_session(conn->sess->se_sess);
+	if (conn->sess->session_index != 0) {
+		spin_lock_bh(&sess_idr_lock);
+		idr_remove(&sess_idr, conn->sess->session_index);
+		spin_unlock_bh(&sess_idr_lock);
+	}
+	kfree(conn->sess->sess_ops);
+	kfree(conn->sess);
+
+old_sess_out:
+	iscsi_stop_login_thread_timer(np);
+	/*
+	 * If login negotiation fails check if the Time2Retain timer
+	 * needs to be restarted.
+	 */
+	if (!zero_tsih && conn->sess) {
+		spin_lock_bh(&conn->sess->conn_lock);
+		if (conn->sess->session_state == TARG_SESS_STATE_FAILED) {
+			struct se_portal_group *se_tpg =
+					&ISCSI_TPG_C(conn)->tpg_se_tpg;
+
+			atomic_set(&conn->sess->session_continuation, 0);
+			spin_unlock_bh(&conn->sess->conn_lock);
+			spin_lock_bh(&se_tpg->session_lock);
+			iscsit_start_time2retain_handler(conn->sess);
+			spin_unlock_bh(&se_tpg->session_lock);
+		} else
+			spin_unlock_bh(&conn->sess->conn_lock);
+		iscsit_dec_session_usage_count(conn->sess);
+	}
+
+	if (!IS_ERR(conn->conn_rx_hash.tfm))
+		crypto_free_hash(conn->conn_rx_hash.tfm);
+	if (!IS_ERR(conn->conn_tx_hash.tfm))
+		crypto_free_hash(conn->conn_tx_hash.tfm);
+
+	if (conn->conn_cpumask)
+		free_cpumask_var(conn->conn_cpumask);
+
+	kfree(conn->conn_ops);
+
+	if (conn->param_list) {
+		iscsi_release_param_list(conn->param_list);
+		conn->param_list = NULL;
+	}
+	iscsi_target_nego_release(conn);
+
+	if (conn->sock) {
+		sock_release(conn->sock);
+		conn->sock = NULL;
+	}
+
+	if (conn->conn_transport->iscsit_free_conn)
+		conn->conn_transport->iscsit_free_conn(conn);
+
+	iscsit_put_transport(conn->conn_transport);
+	kfree(conn);
+}
+
 static int __iscsi_target_login_thread(struct iscsi_np *np)
 {
 	u8 *buffer, zero_tsih = 0;
@@ -1132,6 +1204,8 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
 	struct iscsi_login *login;
 	struct iscsi_portal_group *tpg = NULL;
 	struct iscsi_login_req *pdu;
+	struct iscsi_tpg_np *tpg_np;
+	bool new_sess = false;
 
 	flush_signals(current);
 
@@ -1272,6 +1346,7 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
 		tpg = conn->tpg;
 		goto new_sess_out;
 	}
+	login->zero_tsih = zero_tsih;
 
 	tpg = conn->tpg;
 	if (!tpg) {
@@ -1287,7 +1362,8 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
 			goto old_sess_out;
 	}
 
-	if (iscsi_target_start_negotiation(login, conn) < 0)
+	ret = iscsi_target_start_negotiation(login, conn);
+	if (ret < 0)
 		goto new_sess_out;
 
 	if (!conn->sess) {
@@ -1300,84 +1376,32 @@ static int __iscsi_target_login_thread(struct iscsi_np *np)
 	if (signal_pending(current))
 		goto new_sess_out;
 
-	ret = iscsi_post_login_handler(np, conn, zero_tsih);
+	if (ret == 1) {
+		tpg_np = conn->tpg_np;
 
-	if (ret < 0)
-		goto new_sess_out;
+		ret = iscsi_post_login_handler(np, conn, zero_tsih);
+		if (ret < 0)
+			goto new_sess_out;
+
+		iscsit_deaccess_np(np, tpg, tpg_np);
+	}
 
-	iscsit_deaccess_np(np, tpg);
 	tpg = NULL;
+	tpg_np = NULL;
 	/* Get another socket */
 	return 1;
 
 new_sess_out:
-	pr_err("iSCSI Login negotiation failed.\n");
-	iscsit_collect_login_stats(conn, ISCSI_STATUS_CLS_INITIATOR_ERR,
-				  ISCSI_LOGIN_STATUS_INIT_ERR);
-	if (!zero_tsih || !conn->sess)
-		goto old_sess_out;
-	if (conn->sess->se_sess)
-		transport_free_session(conn->sess->se_sess);
-	if (conn->sess->session_index != 0) {
-		spin_lock_bh(&sess_idr_lock);
-		idr_remove(&sess_idr, conn->sess->session_index);
-		spin_unlock_bh(&sess_idr_lock);
-	}
-	kfree(conn->sess->sess_ops);
-	kfree(conn->sess);
+	new_sess = true;
 old_sess_out:
-	iscsi_stop_login_thread_timer(np);
-	/*
-	 * If login negotiation fails check if the Time2Retain timer
-	 * needs to be restarted.
-	 */
-	if (!zero_tsih && conn->sess) {
-		spin_lock_bh(&conn->sess->conn_lock);
-		if (conn->sess->session_state == TARG_SESS_STATE_FAILED) {
-			struct se_portal_group *se_tpg =
-					&ISCSI_TPG_C(conn)->tpg_se_tpg;
-
-			atomic_set(&conn->sess->session_continuation, 0);
-			spin_unlock_bh(&conn->sess->conn_lock);
-			spin_lock_bh(&se_tpg->session_lock);
-			iscsit_start_time2retain_handler(conn->sess);
-			spin_unlock_bh(&se_tpg->session_lock);
-		} else
-			spin_unlock_bh(&conn->sess->conn_lock);
-		iscsit_dec_session_usage_count(conn->sess);
-	}
-
-	if (!IS_ERR(conn->conn_rx_hash.tfm))
-		crypto_free_hash(conn->conn_rx_hash.tfm);
-	if (!IS_ERR(conn->conn_tx_hash.tfm))
-		crypto_free_hash(conn->conn_tx_hash.tfm);
-
-	if (conn->conn_cpumask)
-		free_cpumask_var(conn->conn_cpumask);
-
-	kfree(conn->conn_ops);
-
-	if (conn->param_list) {
-		iscsi_release_param_list(conn->param_list);
-		conn->param_list = NULL;
-	}
-	iscsi_target_nego_release(conn);
-
-	if (conn->sock) {
-		sock_release(conn->sock);
-		conn->sock = NULL;
-	}
-
-	if (conn->conn_transport->iscsit_free_conn)
-		conn->conn_transport->iscsit_free_conn(conn);
-
-	iscsit_put_transport(conn->conn_transport);
-
-	kfree(conn);
+	tpg_np = conn->tpg_np;
+	iscsi_target_login_sess_out(conn, np, zero_tsih, new_sess);
+	new_sess = false;
 
 	if (tpg) {
-		iscsit_deaccess_np(np, tpg);
+		iscsit_deaccess_np(np, tpg, tpg_np);
 		tpg = NULL;
+		tpg_np = NULL;
 	}
 
 out:
diff --git a/drivers/target/iscsi/iscsi_target_login.h b/drivers/target/iscsi/iscsi_target_login.h
index 63efd28..29d0983 100644
--- a/drivers/target/iscsi/iscsi_target_login.h
+++ b/drivers/target/iscsi/iscsi_target_login.h
@@ -12,6 +12,9 @@ extern int iscsit_accept_np(struct iscsi_np *, struct iscsi_conn *);
 extern int iscsit_get_login_rx(struct iscsi_conn *, struct iscsi_login *);
 extern int iscsit_put_login_tx(struct iscsi_conn *, struct iscsi_login *, u32);
 extern void iscsit_free_conn(struct iscsi_np *, struct iscsi_conn *);
+extern int iscsi_post_login_handler(struct iscsi_np *, struct iscsi_conn *, u8);
+extern void iscsi_target_login_sess_out(struct iscsi_conn *, struct iscsi_np *,
+				bool, bool);
 extern int iscsi_target_login_thread(void *);
 extern int iscsi_login_disable_FIM_keys(struct iscsi_param_list *, struct iscsi_conn *);
 
diff --git a/drivers/target/iscsi/iscsi_target_tpg.c b/drivers/target/iscsi/iscsi_target_tpg.c
index 439260b..c1b1067 100644
--- a/drivers/target/iscsi/iscsi_target_tpg.c
+++ b/drivers/target/iscsi/iscsi_target_tpg.c
@@ -175,18 +175,20 @@ void iscsit_put_tpg(struct iscsi_portal_group *tpg)
 
 static void iscsit_clear_tpg_np_login_thread(
 	struct iscsi_tpg_np *tpg_np,
-	struct iscsi_portal_group *tpg)
+	struct iscsi_portal_group *tpg,
+	bool shutdown)
 {
 	if (!tpg_np->tpg_np) {
 		pr_err("struct iscsi_tpg_np->tpg_np is NULL!\n");
 		return;
 	}
 
-	iscsit_reset_np_thread(tpg_np->tpg_np, tpg_np, tpg);
+	iscsit_reset_np_thread(tpg_np->tpg_np, tpg_np, tpg, shutdown);
 }
 
 void iscsit_clear_tpg_np_login_threads(
-	struct iscsi_portal_group *tpg)
+	struct iscsi_portal_group *tpg,
+	bool shutdown)
 {
 	struct iscsi_tpg_np *tpg_np;
 
@@ -197,7 +199,7 @@ void iscsit_clear_tpg_np_login_threads(
 			continue;
 		}
 		spin_unlock(&tpg->tpg_np_lock);
-		iscsit_clear_tpg_np_login_thread(tpg_np, tpg);
+		iscsit_clear_tpg_np_login_thread(tpg_np, tpg, shutdown);
 		spin_lock(&tpg->tpg_np_lock);
 	}
 	spin_unlock(&tpg->tpg_np_lock);
@@ -268,6 +270,8 @@ int iscsit_tpg_del_portal_group(
 	tpg->tpg_state = TPG_STATE_INACTIVE;
 	spin_unlock(&tpg->tpg_state_lock);
 
+	iscsit_clear_tpg_np_login_threads(tpg, true);
+
 	if (iscsit_release_sessions_for_tpg(tpg, force) < 0) {
 		pr_err("Unable to delete iSCSI Target Portal Group:"
 			" %hu while active sessions exist, and force=0\n",
@@ -368,7 +372,7 @@ int iscsit_tpg_disable_portal_group(struct iscsi_portal_group *tpg, int force)
 	tpg->tpg_state = TPG_STATE_INACTIVE;
 	spin_unlock(&tpg->tpg_state_lock);
 
-	iscsit_clear_tpg_np_login_threads(tpg);
+	iscsit_clear_tpg_np_login_threads(tpg, false);
 
 	if (iscsit_release_sessions_for_tpg(tpg, force) < 0) {
 		spin_lock(&tpg->tpg_state_lock);
@@ -520,7 +524,7 @@ static int iscsit_tpg_release_np(
 	struct iscsi_portal_group *tpg,
 	struct iscsi_np *np)
 {
-	iscsit_clear_tpg_np_login_thread(tpg_np, tpg);
+	iscsit_clear_tpg_np_login_thread(tpg_np, tpg, true);
 
 	pr_debug("CORE[%s] - Removed Network Portal: %s:%hu,%hu on %s\n",
 		tpg->tpg_tiqn->tiqn, np->np_ip, np->np_port, tpg->tpgt,
diff --git a/drivers/target/iscsi/iscsi_target_tpg.h b/drivers/target/iscsi/iscsi_target_tpg.h
index dda48c1..60ef4a9 100644
--- a/drivers/target/iscsi/iscsi_target_tpg.h
+++ b/drivers/target/iscsi/iscsi_target_tpg.h
@@ -8,7 +8,7 @@ extern struct iscsi_portal_group *iscsit_get_tpg_from_np(struct iscsi_tiqn *,
 			struct iscsi_np *);
 extern int iscsit_get_tpg(struct iscsi_portal_group *);
 extern void iscsit_put_tpg(struct iscsi_portal_group *);
-extern void iscsit_clear_tpg_np_login_threads(struct iscsi_portal_group *);
+extern void iscsit_clear_tpg_np_login_threads(struct iscsi_portal_group *, bool);
 extern void iscsit_tpg_dump_params(struct iscsi_portal_group *);
 extern int iscsit_tpg_add_portal_group(struct iscsi_tiqn *, struct iscsi_portal_group *);
 extern int iscsit_tpg_del_portal_group(struct iscsi_tiqn *, struct iscsi_portal_group *,
-- 
1.7.2.5

[PATCH-v2 3/4] iscsi-target: Add login negotiation multi-plexing support

[Nicholas A. Bellinger]

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

This patch adds support for login negotiation multi-plexing in
iscsi-target code.

This involves handling the first login request PDU + payload and
login response PDU + payload within __iscsi_target_login_thread()
process context, and then changing struct sock->sk_data_ready()
so that all subsequent exchanges are handled by workqueue process
context, to allow other incoming login requests to be received
in parallel by __iscsi_target_login_thread().

Upon login negotiation completion (or failure), ->sk_data_ready()
is replaced with the original kernel sockets handler saved in
iscsi_conn->orig_data_ready.

v2 changes:
  - Add login_timer in iscsi_target_do_login_rx() to avoid
    possible endless sleep with MSG_WAITALL for traditional
    iscsi-target in certain network configurations.
  - Convert lprintk() -> pr_debug()
  - Remove forward declarations of iscsi_target_set_sock_callbacks(),
    iscsi_target_restore_sock_callbacks() and iscsi_target_sk_data_ready()
  - Make iscsi_target_set_sock_callbacks + iscsi_target_restore_sock_callbacks()
    static (Fengguang)
  - Make iscsi_target_do_login_rx() safe for iser-target w/o conn->sock

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/iscsi/iscsi_target_core.h |    1 +
 drivers/target/iscsi/iscsi_target_nego.c |  209 ++++++++++++++++++++++++++++-
 drivers/target/iscsi/iscsi_target_tpg.c  |    7 +-
 drivers/target/iscsi/iscsi_target_tpg.h  |    2 +-
 4 files changed, 209 insertions(+), 10 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_core.h b/drivers/target/iscsi/iscsi_target_core.h
index 711a028..8a4c32d 100644
--- a/drivers/target/iscsi/iscsi_target_core.h
+++ b/drivers/target/iscsi/iscsi_target_core.h
@@ -562,6 +562,7 @@ struct iscsi_conn {
 	struct timer_list	nopin_timer;
 	struct timer_list	nopin_response_timer;
 	struct timer_list	transport_timer;
+	struct task_struct	*login_kworker;
 	/* Spinlock used for add/deleting cmd's from conn_cmd_list */
 	spinlock_t		cmd_lock;
 	spinlock_t		conn_usage_lock;
diff --git a/drivers/target/iscsi/iscsi_target_nego.c b/drivers/target/iscsi/iscsi_target_nego.c
index c4675b4..daebe32 100644
--- a/drivers/target/iscsi/iscsi_target_nego.c
+++ b/drivers/target/iscsi/iscsi_target_nego.c
@@ -377,14 +377,191 @@ static int iscsi_target_do_tx_login_io(struct iscsi_conn *conn, struct iscsi_log
 	return 0;
 }
 
+static void iscsi_target_sk_data_ready(struct sock *sk, int count)
+{
+	struct iscsi_conn *conn = sk->sk_user_data;
+	bool rc;
+
+	pr_debug("Entering iscsi_target_sk_data_ready: conn: %p\n", conn);
+
+	read_lock_bh(&sk->sk_callback_lock);
+	if (!sk->sk_user_data) {
+		read_unlock_bh(&sk->sk_callback_lock);
+		return;
+	}
+
+	if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) {
+		read_unlock_bh(&sk->sk_callback_lock);
+		pr_debug("Got LOGIN_FLAGS_READ_ACTIVE=1, conn: %p >>>>\n", conn);
+		return;
+	}
+
+	rc = schedule_delayed_work(&conn->login_work, 0);
+	if (rc == false) {
+		pr_debug("iscsi_target_sk_data_ready, schedule_delayed_work"
+			 " got false\n");
+	}
+	read_unlock_bh(&sk->sk_callback_lock);
+}
+
+static void iscsi_target_set_sock_callbacks(struct iscsi_conn *conn)
+{
+	struct sock *sk;
+
+	if (!conn->sock)
+		return;
+
+	sk = conn->sock->sk;
+	pr_debug("Entering iscsi_target_set_sock_callbacks: conn: %p\n", conn);
+
+	write_lock_bh(&sk->sk_callback_lock);
+	sk->sk_user_data = conn;
+	conn->orig_data_ready = sk->sk_data_ready;
+	sk->sk_data_ready = iscsi_target_sk_data_ready;
+	write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static void iscsi_target_restore_sock_callbacks(struct iscsi_conn *conn)
+{
+	struct sock *sk;
+
+	if (!conn->sock)
+		return;
+
+	sk = conn->sock->sk;
+	pr_debug("Entering iscsi_target_restore_sock_callbacks: conn: %p\n", conn);
+
+	write_lock_bh(&sk->sk_callback_lock);
+	if (!sk->sk_user_data) {
+		write_unlock_bh(&sk->sk_callback_lock);
+		return;
+	}
+	sk->sk_user_data = NULL;
+	sk->sk_data_ready = conn->orig_data_ready;
+	write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static int iscsi_target_do_login(struct iscsi_conn *, struct iscsi_login *);
+
+static bool iscsi_target_sk_state_check(struct sock *sk)
+{
+	if (sk->sk_state == TCP_CLOSE_WAIT || sk->sk_state == TCP_CLOSE) {
+		pr_debug("iscsi_target_sk_state_check: TCP_CLOSE_WAIT|TCP_CLOSE,"
+			"returning FALSE\n");
+		return false;
+	}
+	return true;
+}
+
+static void iscsi_target_login_drop(struct iscsi_conn *conn, struct iscsi_login *login)
+{
+	struct iscsi_np *np = login->np;
+	bool zero_tsih = login->zero_tsih;
+
+	iscsi_remove_failed_auth_entry(conn);
+	iscsi_target_nego_release(conn);
+	iscsi_target_login_sess_out(conn, np, zero_tsih, true);
+}
+
+static void iscsi_target_login_timeout(unsigned long data)
+{
+	struct iscsi_conn *conn = (struct iscsi_conn *)data;
+
+	pr_debug("Entering iscsi_target_login_timeout >>>>>>>>>>>>>>>>>>>\n");
+
+	if (conn->login_kworker) {
+		pr_debug("Sending SIGINT to conn->login_kworker %s/%d\n",
+			 conn->login_kworker->comm, conn->login_kworker->pid);
+		send_sig(SIGINT, conn->login_kworker, 1);
+	}
+}
+
+static void iscsi_target_do_login_rx(struct work_struct *work)
+{
+	struct iscsi_conn *conn = container_of(work,
+				struct iscsi_conn, login_work.work);
+	struct iscsi_login *login = conn->login;
+	struct iscsi_np *np = login->np;
+	struct iscsi_portal_group *tpg = conn->tpg;
+	struct iscsi_tpg_np *tpg_np = conn->tpg_np;
+	struct timer_list login_timer;
+	int rc, zero_tsih = login->zero_tsih;
+	bool state;
+
+	pr_debug("entering iscsi_target_do_login_rx, conn: %p, %s:%d\n",
+			conn, current->comm, current->pid);
+
+	spin_lock(&tpg->tpg_state_lock);
+	state = (tpg->tpg_state == TPG_STATE_ACTIVE);
+	spin_unlock(&tpg->tpg_state_lock);
+
+	if (state == false) {
+		pr_debug("iscsi_target_do_login_rx: tpg_state != TPG_STATE_ACTIVE\n");
+		iscsi_target_restore_sock_callbacks(conn);
+		iscsi_target_login_drop(conn, login);
+		iscsit_deaccess_np(np, tpg, tpg_np);
+		return;
+	}
+
+	if (conn->sock) {
+		struct sock *sk = conn->sock->sk;
+
+		read_lock_bh(&sk->sk_callback_lock);
+		state = iscsi_target_sk_state_check(sk);
+		read_unlock_bh(&sk->sk_callback_lock);
+
+		if (state == false) {
+			pr_debug("iscsi_target_do_login_rx, TCP state CLOSE\n");
+			iscsi_target_restore_sock_callbacks(conn);
+			iscsi_target_login_drop(conn, login);
+			iscsit_deaccess_np(np, tpg, tpg_np);
+			return;
+		}
+	}
+
+	conn->login_kworker = current;
+	allow_signal(SIGINT);
+
+	init_timer(&login_timer);
+	login_timer.expires = (get_jiffies_64() + TA_LOGIN_TIMEOUT * HZ);
+	login_timer.data = (unsigned long)conn;
+	login_timer.function = iscsi_target_login_timeout;
+	add_timer(&login_timer);
+	pr_debug("Starting login_timer for %s/%d\n", current->comm, current->pid);
+
+	rc = conn->conn_transport->iscsit_get_login_rx(conn, login);
+	del_timer_sync(&login_timer);
+	flush_signals(current);
+	conn->login_kworker = NULL;
+
+	if (rc < 0) {
+		iscsi_target_restore_sock_callbacks(conn);
+		iscsi_target_login_drop(conn, login);
+		iscsit_deaccess_np(np, tpg, tpg_np);
+		return;
+	}
+
+	pr_debug("iscsi_target_do_login_rx after rx_login_io, %p, %s:%d\n",
+			conn, current->comm, current->pid);
+
+	rc = iscsi_target_do_login(conn, login);
+	clear_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags);
+	if (rc < 0) {
+		iscsi_target_restore_sock_callbacks(conn);
+		iscsi_target_login_drop(conn, login);
+		iscsit_deaccess_np(np, tpg, tpg_np);
+	} else if (rc == 1) {
+		iscsi_target_nego_release(conn);
+		iscsi_post_login_handler(np, conn, zero_tsih);
+		iscsit_deaccess_np(np, tpg, tpg_np);
+	}
+}
+
 static int iscsi_target_do_login_io(struct iscsi_conn *conn, struct iscsi_login *login)
 {
 	if (iscsi_target_do_tx_login_io(conn, login) < 0)
 		return -1;
 
-	if (conn->conn_transport->iscsit_get_login_rx(conn, login) < 0)
-		return -1;
-
 	return 0;
 }
 
@@ -643,10 +820,11 @@ static int iscsi_target_do_login(struct iscsi_conn *conn, struct iscsi_login *lo
 			if (login_rsp->flags & ISCSI_FLAG_LOGIN_TRANSIT) {
 				login->tsih = conn->sess->tsih;
 				login->login_complete = 1;
+				iscsi_target_restore_sock_callbacks(conn);
 				if (iscsi_target_do_tx_login_io(conn,
 						login) < 0)
 					return -1;
-				return 0;
+				return 1;
 			}
 			break;
 		default:
@@ -663,6 +841,7 @@ static int iscsi_target_do_login(struct iscsi_conn *conn, struct iscsi_login *lo
 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_TRANSIT;
 			login_rsp->flags &= ~ISCSI_FLAG_LOGIN_NEXT_STAGE_MASK;
 		}
+		break;
 	}
 
 	return 0;
@@ -695,10 +874,13 @@ int iscsi_target_locate_portal(
 	char *tmpbuf, *start = NULL, *end = NULL, *key, *value;
 	struct iscsi_session *sess = conn->sess;
 	struct iscsi_tiqn *tiqn;
+	struct iscsi_tpg_np *tpg_np = NULL;
 	struct iscsi_login_req *login_req;
 	u32 payload_length;
 	int sessiontype = 0, ret = 0;
 
+	login->np = np;
+
 	login_req = (struct iscsi_login_req *) login->req;
 	payload_length = ntoh24(login_req->dlength);
 
@@ -822,7 +1004,7 @@ get_target:
 	/*
 	 * Locate Target Portal Group from Storage Node.
 	 */
-	conn->tpg = iscsit_get_tpg_from_np(tiqn, np);
+	conn->tpg = iscsit_get_tpg_from_np(tiqn, np, &tpg_np);
 	if (!conn->tpg) {
 		pr_err("Unable to locate Target Portal Group"
 				" on %s\n", tiqn->tiqn);
@@ -832,12 +1014,16 @@ get_target:
 		ret = -1;
 		goto out;
 	}
+	conn->tpg_np = tpg_np;
 	pr_debug("Located Portal Group Object: %hu\n", conn->tpg->tpgt);
 	/*
 	 * Setup crc32c modules from libcrypto
 	 */
 	if (iscsi_login_setup_crypto(conn) < 0) {
 		pr_err("iscsi_login_setup_crypto() failed\n");
+		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
+		iscsit_put_tiqn_for_login(tiqn);
+		conn->tpg = NULL;
 		ret = -1;
 		goto out;
 	}
@@ -846,11 +1032,12 @@ get_target:
 	 * process login attempt.
 	 */
 	if (iscsit_access_np(np, conn->tpg) < 0) {
+		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
 		iscsit_put_tiqn_for_login(tiqn);
 		iscsit_tx_login_rsp(conn, ISCSI_STATUS_CLS_TARGET_ERR,
 				ISCSI_LOGIN_STATUS_SVC_UNAVAILABLE);
-		ret = -1;
 		conn->tpg = NULL;
+		ret = -1;
 		goto out;
 	}
 
@@ -896,11 +1083,17 @@ int iscsi_target_start_negotiation(
 {
 	int ret;
 
+	INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx);
+	iscsi_target_set_sock_callbacks(conn);
+
 	ret = iscsi_target_do_login(conn, login);
-	if (ret != 0)
+	if (ret < 0) {
+		iscsi_target_restore_sock_callbacks(conn);
 		iscsi_remove_failed_auth_entry(conn);
+	}
+	if (ret != 0)
+		iscsi_target_nego_release(conn);
 
-	iscsi_target_nego_release(conn);
 	return ret;
 }
 
diff --git a/drivers/target/iscsi/iscsi_target_tpg.c b/drivers/target/iscsi/iscsi_target_tpg.c
index c1b1067..6beed70 100644
--- a/drivers/target/iscsi/iscsi_target_tpg.c
+++ b/drivers/target/iscsi/iscsi_target_tpg.c
@@ -129,7 +129,8 @@ void iscsit_release_discovery_tpg(void)
 
 struct iscsi_portal_group *iscsit_get_tpg_from_np(
 	struct iscsi_tiqn *tiqn,
-	struct iscsi_np *np)
+	struct iscsi_np *np,
+	struct iscsi_tpg_np **tpg_np_out)
 {
 	struct iscsi_portal_group *tpg = NULL;
 	struct iscsi_tpg_np *tpg_np;
@@ -147,6 +148,8 @@ struct iscsi_portal_group *iscsit_get_tpg_from_np(
 		spin_lock(&tpg->tpg_np_lock);
 		list_for_each_entry(tpg_np, &tpg->tpg_gnp_list, tpg_np_list) {
 			if (tpg_np->tpg_np == np) {
+				*tpg_np_out = tpg_np;
+				kref_get(&tpg_np->tpg_np_kref);
 				spin_unlock(&tpg->tpg_np_lock);
 				spin_unlock(&tiqn->tiqn_tpg_lock);
 				return tpg;
@@ -494,6 +497,8 @@ struct iscsi_tpg_np *iscsit_tpg_add_network_portal(
 	INIT_LIST_HEAD(&tpg_np->tpg_np_child_list);
 	INIT_LIST_HEAD(&tpg_np->tpg_np_parent_list);
 	spin_lock_init(&tpg_np->tpg_np_parent_lock);
+	init_completion(&tpg_np->tpg_np_comp);
+	kref_init(&tpg_np->tpg_np_kref);
 	tpg_np->tpg_np		= np;
 	tpg_np->tpg		= tpg;
 
diff --git a/drivers/target/iscsi/iscsi_target_tpg.h b/drivers/target/iscsi/iscsi_target_tpg.h
index 60ef4a9..b77693e 100644
--- a/drivers/target/iscsi/iscsi_target_tpg.h
+++ b/drivers/target/iscsi/iscsi_target_tpg.h
@@ -5,7 +5,7 @@ extern struct iscsi_portal_group *iscsit_alloc_portal_group(struct iscsi_tiqn *,
 extern int iscsit_load_discovery_tpg(void);
 extern void iscsit_release_discovery_tpg(void);
 extern struct iscsi_portal_group *iscsit_get_tpg_from_np(struct iscsi_tiqn *,
-			struct iscsi_np *);
+			struct iscsi_np *, struct iscsi_tpg_np **);
 extern int iscsit_get_tpg(struct iscsi_portal_group *);
 extern void iscsit_put_tpg(struct iscsi_portal_group *);
 extern void iscsit_clear_tpg_np_login_threads(struct iscsi_portal_group *, bool);
-- 
1.7.2.5

[PATCH 4/4] iser-target: Updates for login negotiation multi-plexing support

[Nicholas A. Bellinger]

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

This patch updates iser-target code to support login negotiation
multi-plexing.  This includes only using isert_conn->conn_login_comp
for the first login request PDU, pushing the subsequent processing
to iscsi_conn->login_work -> iscsi_target_do_login_rx(), and turning
isert_get_login_rx() into a NOP.

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/infiniband/ulp/isert/ib_isert.c |   17 ++++++++++++++++-
 1 files changed, 16 insertions(+), 1 deletions(-)

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 3f62041..d17ff13 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -869,7 +869,14 @@ isert_rx_login_req(struct iser_rx_desc *rx_desc, int rx_buflen,
 		 size, rx_buflen, MAX_KEY_VALUE_PAIRS);
 	memcpy(login->req_buf, &rx_desc->data[0], size);
 
-	complete(&isert_conn->conn_login_comp);
+	if (login->first_request) {
+		complete(&isert_conn->conn_login_comp);
+		return;
+	}
+	if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags))
+		return;
+
+	schedule_delayed_work(&conn->login_work, 0);
 }
 
 static void
@@ -2224,6 +2231,14 @@ isert_get_login_rx(struct iscsi_conn *conn, struct iscsi_login *login)
 	int ret;
 
 	pr_debug("isert_get_login_rx before conn_login_comp conn: %p\n", conn);
+	/*
+	 * For login requests after the first PDU, isert_rx_login_req() will
+	 * kick schedule_delayed_work(&conn->login_work) as the packet is
+	 * received, which turns this callback from iscsi_target_do_login_rx()
+	 * into a NOP.
+	 */
+	if (!login->first_request)
+		return 0;
 
 	ret = wait_for_completion_interruptible(&isert_conn->conn_login_comp);
 	if (ret)
-- 
1.7.2.5