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Commit 88dcd2da authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

iscsi-target: Convert iscsi_thread_set usage to kthread.h 



This patch converts iscsi-target code to use modern kthread.h API
callers for creating RX/TX threads for each new iscsi_conn descriptor,
and releasing associated RX/TX threads during connection shutdown.

This is done using iscsit_start_kthreads() -> kthread_run() to start
new kthreads from within iscsi_post_login_handler(), and invoking
kthread_stop() from existing iscsit_close_connection() code.

Also, convert iscsit_logout_post_handler_closesession() code to use
cmpxchg when determing when iscsit_cause_connection_reinstatement()
needs to sleep waiting for completion.

Reported-by: default avatarSagi Grimberg <sagig@mellanox.com>
Tested-by: default avatarSagi Grimberg <sagig@mellanox.com>
Cc: Slava Shwartsman <valyushash@gmail.com>
Cc: <stable@vger.kernel.org> # v3.10+
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 5bc6510f

drivers/target/iscsi/iscsi_target.c

+45 −59
Original line number Diff line number Diff line
@@ -537,7 +537,7 @@ static struct iscsit_transport iscsi_target_transport = { 


static int __init iscsi_target_init_module(void)

{

	int ret = 0;

	int ret = 0, size;



	pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");
@@ -546,6 +546,7 @@ static int __init iscsi_target_init_module(void) 
		pr_err("Unable to allocate memory for iscsit_global\n");

		return -1;

	}

	spin_lock_init(&iscsit_global->ts_bitmap_lock);

	mutex_init(&auth_id_lock);

	spin_lock_init(&sess_idr_lock);

	idr_init(&tiqn_idr);
@@ -555,15 +556,11 @@ static int __init iscsi_target_init_module(void) 
	if (ret < 0)

		goto out;



	ret = iscsi_thread_set_init();

	if (ret < 0)

	size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);

	iscsit_global->ts_bitmap = vzalloc(size);

	if (!iscsit_global->ts_bitmap) {

		pr_err("Unable to allocate iscsit_global->ts_bitmap\n");

		goto configfs_out;



	if (iscsi_allocate_thread_sets(TARGET_THREAD_SET_COUNT) !=

			TARGET_THREAD_SET_COUNT) {

		pr_err("iscsi_allocate_thread_sets() returned"

			" unexpected value!\n");

		goto ts_out1;

	}



	lio_qr_cache = kmem_cache_create("lio_qr_cache",
@@ -572,7 +569,7 @@ static int __init iscsi_target_init_module(void) 
	if (!lio_qr_cache) {

		pr_err("nable to kmem_cache_create() for"

				" lio_qr_cache\n");

		goto ts_out2;

		goto bitmap_out;

	}



	lio_dr_cache = kmem_cache_create("lio_dr_cache",
@@ -617,10 +614,8 @@ static int __init iscsi_target_init_module(void) 
	kmem_cache_destroy(lio_dr_cache);

qr_out:

	kmem_cache_destroy(lio_qr_cache);

ts_out2:

	iscsi_deallocate_thread_sets();

ts_out1:

	iscsi_thread_set_free();

bitmap_out:

	vfree(iscsit_global->ts_bitmap);

configfs_out:

	iscsi_target_deregister_configfs();

out:
@@ -630,8 +625,6 @@ static int __init iscsi_target_init_module(void) 


static void __exit iscsi_target_cleanup_module(void)

{

	iscsi_deallocate_thread_sets();

	iscsi_thread_set_free();

	iscsit_release_discovery_tpg();

	iscsit_unregister_transport(&iscsi_target_transport);

	kmem_cache_destroy(lio_qr_cache);
@@ -641,6 +634,7 @@ static void __exit iscsi_target_cleanup_module(void) 


	iscsi_target_deregister_configfs();



	vfree(iscsit_global->ts_bitmap);

	kfree(iscsit_global);

}
@@ -3709,17 +3703,16 @@ static int iscsit_send_reject( 


void iscsit_thread_get_cpumask(struct iscsi_conn *conn)

{

	struct iscsi_thread_set *ts = conn->thread_set;

	int ord, cpu;

	/*

	 * thread_id is assigned from iscsit_global->ts_bitmap from

	 * within iscsi_thread_set.c:iscsi_allocate_thread_sets()

	 * bitmap_id is assigned from iscsit_global->ts_bitmap from

	 * within iscsit_start_kthreads()

	 *

	 * Here we use thread_id to determine which CPU that this

	 * iSCSI connection's iscsi_thread_set will be scheduled to

	 * Here we use bitmap_id to determine which CPU that this

	 * iSCSI connection's RX/TX threads will be scheduled to

	 * execute upon.

	 */

	ord = ts->thread_id % cpumask_weight(cpu_online_mask);

	ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);

	for_each_online_cpu(cpu) {

		if (ord-- == 0) {

			cpumask_set_cpu(cpu, conn->conn_cpumask);
@@ -3908,7 +3901,7 @@ iscsit_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state) 
	switch (state) {

	case ISTATE_SEND_LOGOUTRSP:

		if (!iscsit_logout_post_handler(cmd, conn))

			goto restart;

			return -ECONNRESET;

		/* fall through */

	case ISTATE_SEND_STATUS:

	case ISTATE_SEND_ASYNCMSG:
@@ -3936,8 +3929,6 @@ iscsit_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state) 


err:

	return -1;

restart:

	return -EAGAIN;

}



static int iscsit_handle_response_queue(struct iscsi_conn *conn)
@@ -3964,21 +3955,13 @@ static int iscsit_handle_response_queue(struct iscsi_conn *conn) 
int iscsi_target_tx_thread(void *arg)

{

	int ret = 0;

	struct iscsi_conn *conn;

	struct iscsi_thread_set *ts = arg;

	struct iscsi_conn *conn = arg;

	/*

	 * Allow ourselves to be interrupted by SIGINT so that a

	 * connection recovery / failure event can be triggered externally.

	 */

	allow_signal(SIGINT);



restart:

	conn = iscsi_tx_thread_pre_handler(ts);

	if (!conn)

		goto out;



	ret = 0;



	while (!kthread_should_stop()) {

		/*

		 * Ensure that both TX and RX per connection kthreads
@@ -3987,11 +3970,9 @@ int iscsi_target_tx_thread(void *arg) 
		iscsit_thread_check_cpumask(conn, current, 1);



		wait_event_interruptible(conn->queues_wq,

					 !iscsit_conn_all_queues_empty(conn) ||

					 ts->status == ISCSI_THREAD_SET_RESET);

					 !iscsit_conn_all_queues_empty(conn));



		if ((ts->status == ISCSI_THREAD_SET_RESET) ||

		     signal_pending(current))

		if (signal_pending(current))

			goto transport_err;



get_immediate:
@@ -4002,15 +3983,14 @@ int iscsi_target_tx_thread(void *arg) 
		ret = iscsit_handle_response_queue(conn);

		if (ret == 1)

			goto get_immediate;

		else if (ret == -EAGAIN)

			goto restart;

		else if (ret == -ECONNRESET)

			goto out;

		else if (ret < 0)

			goto transport_err;

	}



transport_err:

	iscsit_take_action_for_connection_exit(conn);

	goto restart;

out:

	return 0;

}
@@ -4105,8 +4085,7 @@ int iscsi_target_rx_thread(void *arg) 
	int ret;

	u8 buffer[ISCSI_HDR_LEN], opcode;

	u32 checksum = 0, digest = 0;

	struct iscsi_conn *conn = NULL;

	struct iscsi_thread_set *ts = arg;

	struct iscsi_conn *conn = arg;

	struct kvec iov;

	/*

	 * Allow ourselves to be interrupted by SIGINT so that a
@@ -4114,11 +4093,6 @@ int iscsi_target_rx_thread(void *arg) 
	 */

	allow_signal(SIGINT);



restart:

	conn = iscsi_rx_thread_pre_handler(ts);

	if (!conn)

		goto out;



	if (conn->conn_transport->transport_type == ISCSI_INFINIBAND) {

		struct completion comp;

		int rc;
@@ -4128,7 +4102,7 @@ int iscsi_target_rx_thread(void *arg) 
		if (rc < 0)

			goto transport_err;



		goto out;

		goto transport_err;

	}



	while (!kthread_should_stop()) {
@@ -4204,8 +4178,6 @@ int iscsi_target_rx_thread(void *arg) 
	if (!signal_pending(current))

		atomic_set(&conn->transport_failed, 1);

	iscsit_take_action_for_connection_exit(conn);

	goto restart;

out:

	return 0;

}
@@ -4261,7 +4233,24 @@ int iscsit_close_connection( 
	 */

	complete(&conn->conn_logout_comp);



	iscsi_release_thread_set(conn);

	if (!strcmp(current->comm, ISCSI_RX_THREAD_NAME)) {

		if (conn->tx_thread &&

		    cmpxchg(&conn->tx_thread_active, true, false)) {

			send_sig(SIGINT, conn->tx_thread, 1);

			kthread_stop(conn->tx_thread);

		}

	} else if (!strcmp(current->comm, ISCSI_TX_THREAD_NAME)) {

		if (conn->rx_thread &&

		    cmpxchg(&conn->rx_thread_active, true, false)) {

			send_sig(SIGINT, conn->rx_thread, 1);

			kthread_stop(conn->rx_thread);

		}

	}



	spin_lock(&iscsit_global->ts_bitmap_lock);

	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,

			      get_order(1));

	spin_unlock(&iscsit_global->ts_bitmap_lock);



	iscsit_stop_timers_for_cmds(conn);

	iscsit_stop_nopin_response_timer(conn);
@@ -4539,15 +4528,13 @@ static void iscsit_logout_post_handler_closesession( 
	struct iscsi_conn *conn)

{

	struct iscsi_session *sess = conn->sess;



	iscsi_set_thread_clear(conn, ISCSI_CLEAR_TX_THREAD);

	iscsi_set_thread_set_signal(conn, ISCSI_SIGNAL_TX_THREAD);

	int sleep = cmpxchg(&conn->tx_thread_active, true, false);



	atomic_set(&conn->conn_logout_remove, 0);

	complete(&conn->conn_logout_comp);



	iscsit_dec_conn_usage_count(conn);

	iscsit_stop_session(sess, 1, 1);

	iscsit_stop_session(sess, sleep, sleep);

	iscsit_dec_session_usage_count(sess);

	target_put_session(sess->se_sess);

}
@@ -4555,13 +4542,12 @@ static void iscsit_logout_post_handler_closesession( 
static void iscsit_logout_post_handler_samecid(

	struct iscsi_conn *conn)

{

	iscsi_set_thread_clear(conn, ISCSI_CLEAR_TX_THREAD);

	iscsi_set_thread_set_signal(conn, ISCSI_SIGNAL_TX_THREAD);

	int sleep = cmpxchg(&conn->tx_thread_active, true, false);



	atomic_set(&conn->conn_logout_remove, 0);

	complete(&conn->conn_logout_comp);



	iscsit_cause_connection_reinstatement(conn, 1);

	iscsit_cause_connection_reinstatement(conn, sleep);

	iscsit_dec_conn_usage_count(conn);

}

drivers/target/iscsi/iscsi_target_erl0.c

+8 −5
Original line number Diff line number Diff line
@@ -861,7 +861,10 @@ void iscsit_connection_reinstatement_rcfr(struct iscsi_conn *conn) 
	}

	spin_unlock_bh(&conn->state_lock);



	iscsi_thread_set_force_reinstatement(conn);

	if (conn->tx_thread && conn->tx_thread_active)

		send_sig(SIGINT, conn->tx_thread, 1);

	if (conn->rx_thread && conn->rx_thread_active)

		send_sig(SIGINT, conn->rx_thread, 1);



sleep:

	wait_for_completion(&conn->conn_wait_rcfr_comp);
@@ -886,10 +889,10 @@ void iscsit_cause_connection_reinstatement(struct iscsi_conn *conn, int sleep) 
		return;

	}



	if (iscsi_thread_set_force_reinstatement(conn) < 0) {

		spin_unlock_bh(&conn->state_lock);

		return;

	}

	if (conn->tx_thread && conn->tx_thread_active)

		send_sig(SIGINT, conn->tx_thread, 1);

	if (conn->rx_thread && conn->rx_thread_active)

		send_sig(SIGINT, conn->rx_thread, 1);



	atomic_set(&conn->connection_reinstatement, 1);

	if (!sleep) {

drivers/target/iscsi/iscsi_target_login.c

+54 −5
Original line number Diff line number Diff line
@@ -699,6 +699,51 @@ static void iscsi_post_login_start_timers(struct iscsi_conn *conn) 
		iscsit_start_nopin_timer(conn);

}



int iscsit_start_kthreads(struct iscsi_conn *conn)

{

	int ret = 0;



	spin_lock(&iscsit_global->ts_bitmap_lock);

	conn->bitmap_id = bitmap_find_free_region(iscsit_global->ts_bitmap,

					ISCSIT_BITMAP_BITS, get_order(1));

	spin_unlock(&iscsit_global->ts_bitmap_lock);



	if (conn->bitmap_id < 0) {

		pr_err("bitmap_find_free_region() failed for"

		       " iscsit_start_kthreads()\n");

		return -ENOMEM;

	}



	conn->tx_thread = kthread_run(iscsi_target_tx_thread, conn,

				      "%s", ISCSI_TX_THREAD_NAME);

	if (IS_ERR(conn->tx_thread)) {

		pr_err("Unable to start iscsi_target_tx_thread\n");

		ret = PTR_ERR(conn->tx_thread);

		goto out_bitmap;

	}

	conn->tx_thread_active = true;



	conn->rx_thread = kthread_run(iscsi_target_rx_thread, conn,

				      "%s", ISCSI_RX_THREAD_NAME);

	if (IS_ERR(conn->rx_thread)) {

		pr_err("Unable to start iscsi_target_rx_thread\n");

		ret = PTR_ERR(conn->rx_thread);

		goto out_tx;

	}

	conn->rx_thread_active = true;



	return 0;

out_tx:

	kthread_stop(conn->tx_thread);

	conn->tx_thread_active = false;

out_bitmap:

	spin_lock(&iscsit_global->ts_bitmap_lock);

	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,

			      get_order(1));

	spin_unlock(&iscsit_global->ts_bitmap_lock);

	return ret;

}



int iscsi_post_login_handler(

	struct iscsi_np *np,

	struct iscsi_conn *conn,
@@ -709,7 +754,7 @@ int iscsi_post_login_handler( 
	struct se_session *se_sess = sess->se_sess;

	struct iscsi_portal_group *tpg = sess->tpg;

	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;

	struct iscsi_thread_set *ts;

	int rc;



	iscsit_inc_conn_usage_count(conn);
@@ -724,7 +769,6 @@ int iscsi_post_login_handler( 
	/*

	 * SCSI Initiator -> SCSI Target Port Mapping

	 */

	ts = iscsi_get_thread_set();

	if (!zero_tsih) {

		iscsi_set_session_parameters(sess->sess_ops,

				conn->param_list, 0);
@@ -751,9 +795,11 @@ int iscsi_post_login_handler( 
			sess->sess_ops->InitiatorName);

		spin_unlock_bh(&sess->conn_lock);



		iscsi_post_login_start_timers(conn);

		rc = iscsit_start_kthreads(conn);

		if (rc)

			return rc;



		iscsi_activate_thread_set(conn, ts);

		iscsi_post_login_start_timers(conn);

		/*

		 * Determine CPU mask to ensure connection's RX and TX kthreads

		 * are scheduled on the same CPU.
@@ -810,8 +856,11 @@ int iscsi_post_login_handler( 
		" iSCSI Target Portal Group: %hu\n", tpg->nsessions, tpg->tpgt);

	spin_unlock_bh(&se_tpg->session_lock);



	rc = iscsit_start_kthreads(conn);

	if (rc)

		return rc;



	iscsi_post_login_start_timers(conn);

	iscsi_activate_thread_set(conn, ts);

	/*

	 * Determine CPU mask to ensure connection's RX and TX kthreads

	 * are scheduled on the same CPU.

include/target/iscsi/iscsi_target_core.h

+7 −0
Original line number Diff line number Diff line
@@ -602,6 +602,11 @@ struct iscsi_conn { 
	struct iscsi_session	*sess;

	/* Pointer to thread_set in use for this conn's threads */

	struct iscsi_thread_set	*thread_set;

	int			bitmap_id;

	int			rx_thread_active;

	struct task_struct	*rx_thread;

	int			tx_thread_active;

	struct task_struct	*tx_thread;

	/* list_head for session connection list */

	struct list_head	conn_list;

} ____cacheline_aligned;
@@ -871,10 +876,12 @@ struct iscsit_global { 
	/* Unique identifier used for the authentication daemon */

	u32			auth_id;

	u32			inactive_ts;

#define ISCSIT_BITMAP_BITS	262144

	/* Thread Set bitmap count */

	int			ts_bitmap_count;

	/* Thread Set bitmap pointer */

	unsigned long		*ts_bitmap;

	spinlock_t		ts_bitmap_lock;

	/* Used for iSCSI discovery session authentication */

	struct iscsi_node_acl	discovery_acl;

	struct iscsi_portal_group	*discovery_tpg;