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Commit d381a801 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

iscsi-target: Add login negotiation multi-plexing support 



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.

v3 changes:
  - Convert iscsi_target_sk_data_ready() lock access to
    write[lock,unlock]_bh()
  - Only clear LOGIN_FLAGS_READ_ACTIVE when iscsi_target_do_login()
    returns zero
  - Add LOGIN_FLAGS_READY + LOGIN_FLAGS_CLOSED bit checks to
    iscsi_target_sk_data_ready()
  - Make INIT_DELAYED_WORK() + iscsi_target_set_sock_callbacks() setup
    happen earlier by moving from iscsi_target_start_negotiation() into
    iscsi_target_locate_portal()
  - Set LOGIN_FLAGS_READY bit in iscsi_target_start_negotiation()
    after iscsi_target_do_login() returns zero.

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: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent a91eb7d9

drivers/target/iscsi/iscsi_target_core.h

+1 −0
Original line number Diff line number Diff line
@@ -564,6 +564,7 @@ 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;

drivers/target/iscsi/iscsi_target_nego.c

+226 −8
Original line number Diff line number Diff line
@@ -377,14 +377,207 @@ 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);



	write_lock_bh(&sk->sk_callback_lock);

	if (!sk->sk_user_data) {

		write_unlock_bh(&sk->sk_callback_lock);

		return;

	}

	if (!test_bit(LOGIN_FLAGS_READY, &conn->login_flags)) {

		write_unlock_bh(&sk->sk_callback_lock);

		pr_debug("Got LOGIN_FLAGS_READY=0, conn: %p >>>>\n", conn);

		return;

	}

	if (test_bit(LOGIN_FLAGS_CLOSED, &conn->login_flags)) {

		write_unlock_bh(&sk->sk_callback_lock);

		pr_debug("Got LOGIN_FLAGS_CLOSED=1, conn: %p >>>>\n", conn);

		return;

	}

	if (test_and_set_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags)) {

		write_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");

	}

	write_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);

	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) {

		if (conn->sock) {

			struct sock *sk = conn->sock->sk;



			write_lock_bh(&sk->sk_callback_lock);

			clear_bit(LOGIN_FLAGS_READ_ACTIVE, &conn->login_flags);

			write_unlock_bh(&sk->sk_callback_lock);

		}

	} 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 +836,11 @@ 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 +857,7 @@ 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 +890,16 @@ 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;



	INIT_DELAYED_WORK(&conn->login_work, iscsi_target_do_login_rx);

	iscsi_target_set_sock_callbacks(conn);



	login->np = np;



	login_req = (struct iscsi_login_req *) login->req;

	payload_length = ntoh24(login_req->dlength);
@@ -822,7 +1023,7 @@ int iscsi_target_locate_portal( 
	/*

	 * 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 +1033,16 @@ int iscsi_target_locate_portal( 
		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 +1051,12 @@ int iscsi_target_locate_portal( 
	 * 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;

	}
@@ -897,10 +1103,22 @@ int iscsi_target_start_negotiation( 
	int ret;



	ret = iscsi_target_do_login(conn, login);

	if (ret != 0)

		iscsi_remove_failed_auth_entry(conn);

	if (!ret) {

		if (conn->sock) {

			struct sock *sk = conn->sock->sk;



			write_lock_bh(&sk->sk_callback_lock);

			set_bit(LOGIN_FLAGS_READY, &conn->login_flags);

			write_unlock_bh(&sk->sk_callback_lock);

		}

	} else if (ret < 0) {

		cancel_delayed_work_sync(&conn->login_work);

		iscsi_target_restore_sock_callbacks(conn);

		iscsi_remove_failed_auth_entry(conn);

	}

	if (ret != 0)

		iscsi_target_nego_release(conn);



	return ret;

}

drivers/target/iscsi/iscsi_target_tpg.c

+6 −1
Original line number Diff line number Diff line
@@ -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;

drivers/target/iscsi/iscsi_target_tpg.h

+1 −1
Original line number Diff line number Diff line
@@ -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);