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Commit defd8848 authored by Nicholas Bellinger's avatar Nicholas Bellinger
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iscsi/iser-target: Fix isert_conn->state hung shutdown issues 



This patch addresses a couple of different hug shutdown issues
related to wait_event() + isert_conn->state.  First, it changes
isert_conn->conn_wait + isert_conn->conn_wait_comp_err from
waitqueues to completions, and sets ISER_CONN_TERMINATING from
within isert_disconnect_work().

Second, it splits isert_free_conn() into isert_wait_conn() that
is called earlier in iscsit_close_connection() to ensure that
all outstanding commands have completed before continuing.

Finally, it breaks isert_cq_comp_err() into seperate TX / RX
related code, and adds logic in isert_cq_rx_comp_err() to wait
for outstanding commands to complete before setting ISER_CONN_DOWN
and calling complete(&isert_conn->conn_wait_comp_err).

Acked-by: default avatarSagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: <stable@vger.kernel.org> #3.10+
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 5159d763

drivers/infiniband/ulp/isert/ib_isert.c

+48 −58
Original line number Diff line number Diff line
@@ -492,8 +492,8 @@ isert_connect_request(struct rdma_cm_id *cma_id, struct rdma_cm_event *event) 
	isert_conn->state = ISER_CONN_INIT;

	INIT_LIST_HEAD(&isert_conn->conn_accept_node);

	init_completion(&isert_conn->conn_login_comp);

	init_waitqueue_head(&isert_conn->conn_wait);

	init_waitqueue_head(&isert_conn->conn_wait_comp_err);

	init_completion(&isert_conn->conn_wait);

	init_completion(&isert_conn->conn_wait_comp_err);

	kref_init(&isert_conn->conn_kref);

	kref_get(&isert_conn->conn_kref);

	mutex_init(&isert_conn->conn_mutex);
@@ -688,11 +688,11 @@ isert_disconnect_work(struct work_struct *work) 


	pr_debug("isert_disconnect_work(): >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");

	mutex_lock(&isert_conn->conn_mutex);

	isert_conn->state = ISER_CONN_DOWN;

	if (isert_conn->state == ISER_CONN_UP)

		isert_conn->state = ISER_CONN_TERMINATING;



	if (isert_conn->post_recv_buf_count == 0 &&

	    atomic_read(&isert_conn->post_send_buf_count) == 0) {

		pr_debug("Calling wake_up(&isert_conn->conn_wait);\n");

		mutex_unlock(&isert_conn->conn_mutex);

		goto wake_up;

	}
@@ -712,7 +712,7 @@ isert_disconnect_work(struct work_struct *work) 
	mutex_unlock(&isert_conn->conn_mutex);



wake_up:

	wake_up(&isert_conn->conn_wait);

	complete(&isert_conn->conn_wait);

	isert_put_conn(isert_conn);

}
@@ -1589,7 +1589,7 @@ isert_do_control_comp(struct work_struct *work) 
		pr_debug("Calling iscsit_logout_post_handler >>>>>>>>>>>>>>\n");

		/*

		 * Call atomic_dec(&isert_conn->post_send_buf_count)

		 * from isert_free_conn()

		 * from isert_wait_conn()

		 */

		isert_conn->logout_posted = true;

		iscsit_logout_post_handler(cmd, cmd->conn);
@@ -1691,11 +1691,9 @@ isert_send_completion(struct iser_tx_desc *tx_desc, 
}



static void

isert_cq_comp_err(struct iser_tx_desc *tx_desc, struct isert_conn *isert_conn)

isert_cq_tx_comp_err(struct iser_tx_desc *tx_desc, struct isert_conn *isert_conn)

{

	struct ib_device *ib_dev = isert_conn->conn_cm_id->device;



	if (tx_desc) {

	struct isert_cmd *isert_cmd = tx_desc->isert_cmd;



	if (!isert_cmd)
@@ -1704,18 +1702,28 @@ isert_cq_comp_err(struct iser_tx_desc *tx_desc, struct isert_conn *isert_conn) 
		isert_completion_put(tx_desc, isert_cmd, ib_dev);

}



	if (isert_conn->post_recv_buf_count == 0 &&

	    atomic_read(&isert_conn->post_send_buf_count) == 0) {

		pr_debug("isert_cq_comp_err >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>\n");

		pr_debug("Calling wake_up from isert_cq_comp_err\n");

static void

isert_cq_rx_comp_err(struct isert_conn *isert_conn)

{

	struct ib_device *ib_dev = isert_conn->conn_cm_id->device;

	struct iscsi_conn *conn = isert_conn->conn;



	if (isert_conn->post_recv_buf_count)

		return;



	if (conn->sess) {

		target_sess_cmd_list_set_waiting(conn->sess->se_sess);

		target_wait_for_sess_cmds(conn->sess->se_sess);

	}



	while (atomic_read(&isert_conn->post_send_buf_count))

		msleep(3000);



	mutex_lock(&isert_conn->conn_mutex);

		if (isert_conn->state != ISER_CONN_DOWN)

			isert_conn->state = ISER_CONN_TERMINATING;

	isert_conn->state = ISER_CONN_DOWN;

	mutex_unlock(&isert_conn->conn_mutex);



		wake_up(&isert_conn->conn_wait_comp_err);

	}

	complete(&isert_conn->conn_wait_comp_err);

}



static void
@@ -1740,8 +1748,9 @@ isert_cq_tx_work(struct work_struct *work) 
			pr_debug("TX wc.status != IB_WC_SUCCESS >>>>>>>>>>>>>>\n");

			pr_debug("TX wc.status: 0x%08x\n", wc.status);

			pr_debug("TX wc.vendor_err: 0x%08x\n", wc.vendor_err);



			atomic_dec(&isert_conn->post_send_buf_count);

			isert_cq_comp_err(tx_desc, isert_conn);

			isert_cq_tx_comp_err(tx_desc, isert_conn);

		}

	}
@@ -1784,7 +1793,7 @@ isert_cq_rx_work(struct work_struct *work) 
					 wc.vendor_err);

			}

			isert_conn->post_recv_buf_count--;

			isert_cq_comp_err(NULL, isert_conn);

			isert_cq_rx_comp_err(isert_conn);

		}

	}
@@ -2702,22 +2711,11 @@ isert_free_np(struct iscsi_np *np) 
	kfree(isert_np);

}



static int isert_check_state(struct isert_conn *isert_conn, int state)

{

	int ret;



	mutex_lock(&isert_conn->conn_mutex);

	ret = (isert_conn->state == state);

	mutex_unlock(&isert_conn->conn_mutex);



	return ret;

}



static void isert_free_conn(struct iscsi_conn *conn)

static void isert_wait_conn(struct iscsi_conn *conn)

{

	struct isert_conn *isert_conn = conn->context;



	pr_debug("isert_free_conn: Starting \n");

	pr_debug("isert_wait_conn: Starting \n");

	/*

	 * Decrement post_send_buf_count for special case when called

	 * from isert_do_control_comp() -> iscsit_logout_post_handler()
@@ -2727,38 +2725,29 @@ static void isert_free_conn(struct iscsi_conn *conn) 
		atomic_dec(&isert_conn->post_send_buf_count);



	if (isert_conn->conn_cm_id && isert_conn->state != ISER_CONN_DOWN) {

		pr_debug("Calling rdma_disconnect from isert_free_conn\n");

		pr_debug("Calling rdma_disconnect from isert_wait_conn\n");

		rdma_disconnect(isert_conn->conn_cm_id);

	}

	/*

	 * Only wait for conn_wait_comp_err if the isert_conn made it

	 * into full feature phase..

	 */

	if (isert_conn->state == ISER_CONN_UP) {

		pr_debug("isert_free_conn: Before wait_event comp_err %d\n",

			 isert_conn->state);

		mutex_unlock(&isert_conn->conn_mutex);



		wait_event(isert_conn->conn_wait_comp_err,

			  (isert_check_state(isert_conn, ISER_CONN_TERMINATING)));



		wait_event(isert_conn->conn_wait,

			  (isert_check_state(isert_conn, ISER_CONN_DOWN)));



		isert_put_conn(isert_conn);

		return;

	}

	if (isert_conn->state == ISER_CONN_INIT) {

		mutex_unlock(&isert_conn->conn_mutex);

		isert_put_conn(isert_conn);

		return;

	}

	pr_debug("isert_free_conn: wait_event conn_wait %d\n",

		 isert_conn->state);

	if (isert_conn->state == ISER_CONN_UP)

		isert_conn->state = ISER_CONN_TERMINATING;

	mutex_unlock(&isert_conn->conn_mutex);



	wait_event(isert_conn->conn_wait,

		  (isert_check_state(isert_conn, ISER_CONN_DOWN)));

	wait_for_completion(&isert_conn->conn_wait_comp_err);



	wait_for_completion(&isert_conn->conn_wait);

}



static void isert_free_conn(struct iscsi_conn *conn)

{

	struct isert_conn *isert_conn = conn->context;



	isert_put_conn(isert_conn);

}
@@ -2771,6 +2760,7 @@ static struct iscsit_transport iser_target_transport = { 
	.iscsit_setup_np	= isert_setup_np,

	.iscsit_accept_np	= isert_accept_np,

	.iscsit_free_np		= isert_free_np,

	.iscsit_wait_conn	= isert_wait_conn,

	.iscsit_free_conn	= isert_free_conn,

	.iscsit_get_login_rx	= isert_get_login_rx,

	.iscsit_put_login_tx	= isert_put_login_tx,

drivers/infiniband/ulp/isert/ib_isert.h

+2 −2
Original line number Diff line number Diff line
@@ -116,8 +116,8 @@ struct isert_conn { 
	struct isert_device	*conn_device;

	struct work_struct	conn_logout_work;

	struct mutex		conn_mutex;

	wait_queue_head_t	conn_wait;

	wait_queue_head_t	conn_wait_comp_err;

	struct completion	conn_wait;

	struct completion	conn_wait_comp_err;

	struct kref		conn_kref;

	struct list_head	conn_fr_pool;

	int			conn_fr_pool_size;

drivers/target/iscsi/iscsi_target.c

+4 −0
Original line number Diff line number Diff line
@@ -4196,6 +4196,10 @@ int iscsit_close_connection( 
	iscsit_stop_timers_for_cmds(conn);

	iscsit_stop_nopin_response_timer(conn);

	iscsit_stop_nopin_timer(conn);



	if (conn->conn_transport->iscsit_wait_conn)

		conn->conn_transport->iscsit_wait_conn(conn);



	iscsit_free_queue_reqs_for_conn(conn);



	/*

include/target/iscsi/iscsi_transport.h

+1 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ struct iscsit_transport { 
	int (*iscsit_setup_np)(struct iscsi_np *, struct __kernel_sockaddr_storage *);

	int (*iscsit_accept_np)(struct iscsi_np *, struct iscsi_conn *);

	void (*iscsit_free_np)(struct iscsi_np *);

	void (*iscsit_wait_conn)(struct iscsi_conn *);

	void (*iscsit_free_conn)(struct iscsi_conn *);

	int (*iscsit_get_login_rx)(struct iscsi_conn *, struct iscsi_login *);

	int (*iscsit_put_login_tx)(struct iscsi_conn *, struct iscsi_login *, u32);