[mirror_ubuntu-jammy-kernel.git] / net / smc / smc_close.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 *  Socket Closing - normal and abnormal
 *
 *  Copyright IBM Corp. 2016
 *
 *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 */

#include <linux/workqueue.h>
#include <linux/sched/signal.h>

#include <net/sock.h>
#include <net/tcp.h>

#include "smc.h"
#include "smc_tx.h"
#include "smc_cdc.h"
#include "smc_close.h"

/* release the clcsock that is assigned to the smc_sock */
void smc_clcsock_release(struct smc_sock *smc)
{
	struct socket *tcp;

	if (smc->listen_smc && current_work() != &smc->smc_listen_work)
		cancel_work_sync(&smc->smc_listen_work);
	mutex_lock(&smc->clcsock_release_lock);
	if (smc->clcsock) {
		tcp = smc->clcsock;
		smc->clcsock = NULL;
		sock_release(tcp);
	}
	mutex_unlock(&smc->clcsock_release_lock);
}

static void smc_close_cleanup_listen(struct sock *parent)
{
	struct sock *sk;

	/* Close non-accepted connections */
	while ((sk = smc_accept_dequeue(parent, NULL)))
		smc_close_non_accepted(sk);
}

/* wait for sndbuf data being transmitted */
static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
{
	DEFINE_WAIT_FUNC(wait, woken_wake_function);
	struct sock *sk = &smc->sk;

	if (!timeout)
		return;

	if (!smc_tx_prepared_sends(&smc->conn))
		return;

	smc->wait_close_tx_prepared = 1;
	add_wait_queue(sk_sleep(sk), &wait);
	while (!signal_pending(current) && timeout) {
		int rc;

		rc = sk_wait_event(sk, &timeout,
				   !smc_tx_prepared_sends(&smc->conn) ||
				   sk->sk_err == ECONNABORTED ||
				   sk->sk_err == ECONNRESET ||
				   smc->conn.killed,
				   &wait);
		if (rc)
			break;
	}
	remove_wait_queue(sk_sleep(sk), &wait);
	smc->wait_close_tx_prepared = 0;
}

void smc_close_wake_tx_prepared(struct smc_sock *smc)
{
	if (smc->wait_close_tx_prepared)
		/* wake up socket closing */
		smc->sk.sk_state_change(&smc->sk);
}

static int smc_close_wr(struct smc_connection *conn)
{
	conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;

	return smc_cdc_get_slot_and_msg_send(conn);
}

static int smc_close_final(struct smc_connection *conn)
{
	if (atomic_read(&conn->bytes_to_rcv))
		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
	else
		conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
	if (conn->killed)
		return -EPIPE;

	return smc_cdc_get_slot_and_msg_send(conn);
}

int smc_close_abort(struct smc_connection *conn)
{
	conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;

	return smc_cdc_get_slot_and_msg_send(conn);
}

static void smc_close_cancel_work(struct smc_sock *smc)
{
	struct sock *sk = &smc->sk;

	release_sock(sk);
	cancel_work_sync(&smc->conn.close_work);
	cancel_delayed_work_sync(&smc->conn.tx_work);
	lock_sock(sk);
}

/* terminate smc socket abnormally - active abort
 * link group is terminated, i.e. RDMA communication no longer possible
 */
void smc_close_active_abort(struct smc_sock *smc)
{
	struct sock *sk = &smc->sk;
	bool release_clcsock = false;

	if (sk->sk_state != SMC_INIT && smc->clcsock && smc->clcsock->sk) {
		sk->sk_err = ECONNABORTED;
		if (smc->clcsock && smc->clcsock->sk)
			tcp_abort(smc->clcsock->sk, ECONNABORTED);
	}
	switch (sk->sk_state) {
	case SMC_ACTIVE:
	case SMC_APPCLOSEWAIT1:
	case SMC_APPCLOSEWAIT2:
		sk->sk_state = SMC_PEERABORTWAIT;
		smc_close_cancel_work(smc);
		if (sk->sk_state != SMC_PEERABORTWAIT)
			break;
		sk->sk_state = SMC_CLOSED;
		sock_put(sk); /* (postponed) passive closing */
		break;
	case SMC_PEERCLOSEWAIT1:
	case SMC_PEERCLOSEWAIT2:
	case SMC_PEERFINCLOSEWAIT:
		sk->sk_state = SMC_PEERABORTWAIT;
		smc_close_cancel_work(smc);
		if (sk->sk_state != SMC_PEERABORTWAIT)
			break;
		sk->sk_state = SMC_CLOSED;
		smc_conn_free(&smc->conn);
		release_clcsock = true;
		sock_put(sk); /* passive closing */
		break;
	case SMC_PROCESSABORT:
	case SMC_APPFINCLOSEWAIT:
		sk->sk_state = SMC_PEERABORTWAIT;
		smc_close_cancel_work(smc);
		if (sk->sk_state != SMC_PEERABORTWAIT)
			break;
		sk->sk_state = SMC_CLOSED;
		smc_conn_free(&smc->conn);
		release_clcsock = true;
		break;
	case SMC_INIT:
	case SMC_PEERABORTWAIT:
	case SMC_CLOSED:
		break;
	}

	sock_set_flag(sk, SOCK_DEAD);
	sk->sk_state_change(sk);

	if (release_clcsock) {
		release_sock(sk);
		smc_clcsock_release(smc);
		lock_sock(sk);
	}
}

static inline bool smc_close_sent_any_close(struct smc_connection *conn)
{
	return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
	       conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
}

int smc_close_active(struct smc_sock *smc)
{
	struct smc_cdc_conn_state_flags *txflags =
		&smc->conn.local_tx_ctrl.conn_state_flags;
	struct smc_connection *conn = &smc->conn;
	struct sock *sk = &smc->sk;
	int old_state;
	long timeout;
	int rc = 0;
	int rc1 = 0;

	timeout = current->flags & PF_EXITING ?
		  0 : sock_flag(sk, SOCK_LINGER) ?
		      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;

	old_state = sk->sk_state;
again:
	switch (sk->sk_state) {
	case SMC_INIT:
		sk->sk_state = SMC_CLOSED;
		break;
	case SMC_LISTEN:
		sk->sk_state = SMC_CLOSED;
		sk->sk_state_change(sk); /* wake up accept */
		if (smc->clcsock && smc->clcsock->sk) {
			smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
			smc->clcsock->sk->sk_user_data = NULL;
			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
		}
		smc_close_cleanup_listen(sk);
		release_sock(sk);
		flush_work(&smc->tcp_listen_work);
		lock_sock(sk);
		break;
	case SMC_ACTIVE:
		smc_close_stream_wait(smc, timeout);
		release_sock(sk);
		cancel_delayed_work_sync(&conn->tx_work);
		lock_sock(sk);
		if (sk->sk_state == SMC_ACTIVE) {
			/* send close request */
			rc = smc_close_final(conn);
			sk->sk_state = SMC_PEERCLOSEWAIT1;

			/* actively shutdown clcsock before peer close it,
			 * prevent peer from entering TIME_WAIT state.
			 */
			if (smc->clcsock && smc->clcsock->sk) {
				rc1 = kernel_sock_shutdown(smc->clcsock,
							   SHUT_RDWR);
				rc = rc ? rc : rc1;
			}
		} else {
			/* peer event has changed the state */
			goto again;
		}
		break;
	case SMC_APPFINCLOSEWAIT:
		/* socket already shutdown wr or both (active close) */
		if (txflags->peer_done_writing &&
		    !smc_close_sent_any_close(conn)) {
			/* just shutdown wr done, send close request */
			rc = smc_close_final(conn);
		}
		sk->sk_state = SMC_CLOSED;
		break;
	case SMC_APPCLOSEWAIT1:
	case SMC_APPCLOSEWAIT2:
		if (!smc_cdc_rxed_any_close(conn))
			smc_close_stream_wait(smc, timeout);
		release_sock(sk);
		cancel_delayed_work_sync(&conn->tx_work);
		lock_sock(sk);
		if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
		    sk->sk_state != SMC_APPCLOSEWAIT2)
			goto again;
		/* confirm close from peer */
		rc = smc_close_final(conn);
		if (smc_cdc_rxed_any_close(conn)) {
			/* peer has closed the socket already */
			sk->sk_state = SMC_CLOSED;
			sock_put(sk); /* postponed passive closing */
		} else {
			/* peer has just issued a shutdown write */
			sk->sk_state = SMC_PEERFINCLOSEWAIT;
		}
		break;
	case SMC_PEERCLOSEWAIT1:
	case SMC_PEERCLOSEWAIT2:
		if (txflags->peer_done_writing &&
		    !smc_close_sent_any_close(conn)) {
			/* just shutdown wr done, send close request */
			rc = smc_close_final(conn);
		}
		/* peer sending PeerConnectionClosed will cause transition */
		break;
	case SMC_PEERFINCLOSEWAIT:
		/* peer sending PeerConnectionClosed will cause transition */
		break;
	case SMC_PROCESSABORT:
		rc = smc_close_abort(conn);
		sk->sk_state = SMC_CLOSED;
		break;
	case SMC_PEERABORTWAIT:
		sk->sk_state = SMC_CLOSED;
		break;
	case SMC_CLOSED:
		/* nothing to do, add tracing in future patch */
		break;
	}

	if (old_state != sk->sk_state)
		sk->sk_state_change(sk);
	return rc;
}

static void smc_close_passive_abort_received(struct smc_sock *smc)
{
	struct smc_cdc_conn_state_flags *txflags =
		&smc->conn.local_tx_ctrl.conn_state_flags;
	struct sock *sk = &smc->sk;

	switch (sk->sk_state) {
	case SMC_INIT:
	case SMC_ACTIVE:
	case SMC_APPCLOSEWAIT1:
		sk->sk_state = SMC_PROCESSABORT;
		sock_put(sk); /* passive closing */
		break;
	case SMC_APPFINCLOSEWAIT:
		sk->sk_state = SMC_PROCESSABORT;
		break;
	case SMC_PEERCLOSEWAIT1:
	case SMC_PEERCLOSEWAIT2:
		if (txflags->peer_done_writing &&
		    !smc_close_sent_any_close(&smc->conn))
			/* just shutdown, but not yet closed locally */
			sk->sk_state = SMC_PROCESSABORT;
		else
			sk->sk_state = SMC_CLOSED;
		sock_put(sk); /* passive closing */
		break;
	case SMC_APPCLOSEWAIT2:
	case SMC_PEERFINCLOSEWAIT:
		sk->sk_state = SMC_CLOSED;
		sock_put(sk); /* passive closing */
		break;
	case SMC_PEERABORTWAIT:
		sk->sk_state = SMC_CLOSED;
		break;
	case SMC_PROCESSABORT:
	/* nothing to do, add tracing in future patch */
		break;
	}
}

/* Either some kind of closing has been received: peer_conn_closed,
 * peer_conn_abort, or peer_done_writing
 * or the link group of the connection terminates abnormally.
 */
static void smc_close_passive_work(struct work_struct *work)
{
	struct smc_connection *conn = container_of(work,
						   struct smc_connection,
						   close_work);
	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
	struct smc_cdc_conn_state_flags *rxflags;
	bool release_clcsock = false;
	struct sock *sk = &smc->sk;
	int old_state;

	lock_sock(sk);
	old_state = sk->sk_state;

	rxflags = &conn->local_rx_ctrl.conn_state_flags;
	if (rxflags->peer_conn_abort) {
		/* peer has not received all data */
		smc_close_passive_abort_received(smc);
		release_sock(&smc->sk);
		cancel_delayed_work_sync(&conn->tx_work);
		lock_sock(&smc->sk);
		goto wakeup;
	}

	switch (sk->sk_state) {
	case SMC_INIT:
		sk->sk_state = SMC_APPCLOSEWAIT1;
		break;
	case SMC_ACTIVE:
		sk->sk_state = SMC_APPCLOSEWAIT1;
		/* postpone sock_put() for passive closing to cover
		 * received SEND_SHUTDOWN as well
		 */
		break;
	case SMC_PEERCLOSEWAIT1:
		if (rxflags->peer_done_writing)
			sk->sk_state = SMC_PEERCLOSEWAIT2;
		fallthrough;
		/* to check for closing */
	case SMC_PEERCLOSEWAIT2:
		if (!smc_cdc_rxed_any_close(conn))
			break;
		if (sock_flag(sk, SOCK_DEAD) &&
		    smc_close_sent_any_close(conn)) {
			/* smc_release has already been called locally */
			sk->sk_state = SMC_CLOSED;
		} else {
			/* just shutdown, but not yet closed locally */
			sk->sk_state = SMC_APPFINCLOSEWAIT;
		}
		sock_put(sk); /* passive closing */
		break;
	case SMC_PEERFINCLOSEWAIT:
		if (smc_cdc_rxed_any_close(conn)) {
			sk->sk_state = SMC_CLOSED;
			sock_put(sk); /* passive closing */
		}
		break;
	case SMC_APPCLOSEWAIT1:
	case SMC_APPCLOSEWAIT2:
		/* postpone sock_put() for passive closing to cover
		 * received SEND_SHUTDOWN as well
		 */
		break;
	case SMC_APPFINCLOSEWAIT:
	case SMC_PEERABORTWAIT:
	case SMC_PROCESSABORT:
	case SMC_CLOSED:
		/* nothing to do, add tracing in future patch */
		break;
	}

wakeup:
	sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
	sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */

	if (old_state != sk->sk_state) {
		sk->sk_state_change(sk);
		if ((sk->sk_state == SMC_CLOSED) &&
		    (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
			smc_conn_free(conn);
			if (smc->clcsock)
				release_clcsock = true;
		}
	}
	release_sock(sk);
	if (release_clcsock)
		smc_clcsock_release(smc);
	sock_put(sk); /* sock_hold done by schedulers of close_work */
}

int smc_close_shutdown_write(struct smc_sock *smc)
{
	struct smc_connection *conn = &smc->conn;
	struct sock *sk = &smc->sk;
	int old_state;
	long timeout;
	int rc = 0;

	timeout = current->flags & PF_EXITING ?
		  0 : sock_flag(sk, SOCK_LINGER) ?
		      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;

	old_state = sk->sk_state;
again:
	switch (sk->sk_state) {
	case SMC_ACTIVE:
		smc_close_stream_wait(smc, timeout);
		release_sock(sk);
		cancel_delayed_work_sync(&conn->tx_work);
		lock_sock(sk);
		if (sk->sk_state != SMC_ACTIVE)
			goto again;
		/* send close wr request */
		rc = smc_close_wr(conn);
		sk->sk_state = SMC_PEERCLOSEWAIT1;
		break;
	case SMC_APPCLOSEWAIT1:
		/* passive close */
		if (!smc_cdc_rxed_any_close(conn))
			smc_close_stream_wait(smc, timeout);
		release_sock(sk);
		cancel_delayed_work_sync(&conn->tx_work);
		lock_sock(sk);
		if (sk->sk_state != SMC_APPCLOSEWAIT1)
			goto again;
		/* confirm close from peer */
		rc = smc_close_wr(conn);
		sk->sk_state = SMC_APPCLOSEWAIT2;
		break;
	case SMC_APPCLOSEWAIT2:
	case SMC_PEERFINCLOSEWAIT:
	case SMC_PEERCLOSEWAIT1:
	case SMC_PEERCLOSEWAIT2:
	case SMC_APPFINCLOSEWAIT:
	case SMC_PROCESSABORT:
	case SMC_PEERABORTWAIT:
		/* nothing to do, add tracing in future patch */
		break;
	}

	if (old_state != sk->sk_state)
		sk->sk_state_change(sk);
	return rc;
}

/* Initialize close properties on connection establishment. */
void smc_close_init(struct smc_sock *smc)
{
	INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
}
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Shared Memory Communications over RDMA (SMC-R) and RoCE
	4	*
	5	* Socket Closing - normal and abnormal
	6	*
	7	* Copyright IBM Corp. 2016
	8	*
	9	* Author(s): Ursula Braun <ubraun@linux.vnet.ibm.com>
	10	*/
	11
	12	#include <linux/workqueue.h>
	13	#include <linux/sched/signal.h>
	14
	15	#include <net/sock.h>
	16	#include <net/tcp.h>
	17
	18	#include "smc.h"
	19	#include "smc_tx.h"
	20	#include "smc_cdc.h"
	21	#include "smc_close.h"
	22
	23	/* release the clcsock that is assigned to the smc_sock */
	24	void smc_clcsock_release(struct smc_sock *smc)
	25	{
	26	struct socket *tcp;
	27
	28	if (smc->listen_smc && current_work() != &smc->smc_listen_work)
	29	cancel_work_sync(&smc->smc_listen_work);
	30	mutex_lock(&smc->clcsock_release_lock);
	31	if (smc->clcsock) {
	32	tcp = smc->clcsock;
	33	smc->clcsock = NULL;
	34	sock_release(tcp);
	35	}
	36	mutex_unlock(&smc->clcsock_release_lock);
	37	}
	38
	39	static void smc_close_cleanup_listen(struct sock *parent)
	40	{
	41	struct sock *sk;
	42
	43	/* Close non-accepted connections */
	44	while ((sk = smc_accept_dequeue(parent, NULL)))
	45	smc_close_non_accepted(sk);
	46	}
	47
	48	/* wait for sndbuf data being transmitted */
	49	static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
	50	{
	51	DEFINE_WAIT_FUNC(wait, woken_wake_function);
	52	struct sock *sk = &smc->sk;
	53
	54	if (!timeout)
	55	return;
	56
	57	if (!smc_tx_prepared_sends(&smc->conn))
	58	return;
	59
	60	smc->wait_close_tx_prepared = 1;
	61	add_wait_queue(sk_sleep(sk), &wait);
	62	while (!signal_pending(current) && timeout) {
	63	int rc;
	64
	65	rc = sk_wait_event(sk, &timeout,
	66	!smc_tx_prepared_sends(&smc->conn) \|\|
	67	sk->sk_err == ECONNABORTED \|\|
	68	sk->sk_err == ECONNRESET \|\|
	69	smc->conn.killed,
	70	&wait);
	71	if (rc)
	72	break;
	73	}
	74	remove_wait_queue(sk_sleep(sk), &wait);
	75	smc->wait_close_tx_prepared = 0;
	76	}
	77
	78	void smc_close_wake_tx_prepared(struct smc_sock *smc)
	79	{
	80	if (smc->wait_close_tx_prepared)
	81	/* wake up socket closing */
	82	smc->sk.sk_state_change(&smc->sk);
	83	}
	84
	85	static int smc_close_wr(struct smc_connection *conn)
	86	{
	87	conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;
	88
	89	return smc_cdc_get_slot_and_msg_send(conn);
	90	}
	91
	92	static int smc_close_final(struct smc_connection *conn)
	93	{
	94	if (atomic_read(&conn->bytes_to_rcv))
	95	conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
	96	else
	97	conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
	98	if (conn->killed)
	99	return -EPIPE;
	100
	101	return smc_cdc_get_slot_and_msg_send(conn);
	102	}
	103
	104	int smc_close_abort(struct smc_connection *conn)
	105	{
	106	conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
	107
	108	return smc_cdc_get_slot_and_msg_send(conn);
	109	}
	110
	111	static void smc_close_cancel_work(struct smc_sock *smc)
	112	{
	113	struct sock *sk = &smc->sk;
	114
	115	release_sock(sk);
	116	cancel_work_sync(&smc->conn.close_work);
	117	cancel_delayed_work_sync(&smc->conn.tx_work);
	118	lock_sock(sk);
	119	}
	120
	121	/* terminate smc socket abnormally - active abort
	122	* link group is terminated, i.e. RDMA communication no longer possible
	123	*/
	124	void smc_close_active_abort(struct smc_sock *smc)
	125	{
	126	struct sock *sk = &smc->sk;
	127	bool release_clcsock = false;
	128
	129	if (sk->sk_state != SMC_INIT && smc->clcsock && smc->clcsock->sk) {
	130	sk->sk_err = ECONNABORTED;
	131	if (smc->clcsock && smc->clcsock->sk)
	132	tcp_abort(smc->clcsock->sk, ECONNABORTED);
	133	}
	134	switch (sk->sk_state) {
	135	case SMC_ACTIVE:
	136	case SMC_APPCLOSEWAIT1:
	137	case SMC_APPCLOSEWAIT2:
	138	sk->sk_state = SMC_PEERABORTWAIT;
	139	smc_close_cancel_work(smc);
	140	if (sk->sk_state != SMC_PEERABORTWAIT)
	141	break;
	142	sk->sk_state = SMC_CLOSED;
	143	sock_put(sk); /* (postponed) passive closing */
	144	break;
	145	case SMC_PEERCLOSEWAIT1:
	146	case SMC_PEERCLOSEWAIT2:
	147	case SMC_PEERFINCLOSEWAIT:
	148	sk->sk_state = SMC_PEERABORTWAIT;
	149	smc_close_cancel_work(smc);
	150	if (sk->sk_state != SMC_PEERABORTWAIT)
	151	break;
	152	sk->sk_state = SMC_CLOSED;
	153	smc_conn_free(&smc->conn);
	154	release_clcsock = true;
	155	sock_put(sk); /* passive closing */
	156	break;
	157	case SMC_PROCESSABORT:
	158	case SMC_APPFINCLOSEWAIT:
	159	sk->sk_state = SMC_PEERABORTWAIT;
	160	smc_close_cancel_work(smc);
	161	if (sk->sk_state != SMC_PEERABORTWAIT)
	162	break;
	163	sk->sk_state = SMC_CLOSED;
	164	smc_conn_free(&smc->conn);
	165	release_clcsock = true;
	166	break;
	167	case SMC_INIT:
	168	case SMC_PEERABORTWAIT:
	169	case SMC_CLOSED:
	170	break;
	171	}
	172
	173	sock_set_flag(sk, SOCK_DEAD);
	174	sk->sk_state_change(sk);
	175
	176	if (release_clcsock) {
	177	release_sock(sk);
	178	smc_clcsock_release(smc);
	179	lock_sock(sk);
	180	}
	181	}
	182
	183	static inline bool smc_close_sent_any_close(struct smc_connection *conn)
	184	{
	185	return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort \|\|
	186	conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
	187	}
	188
	189	int smc_close_active(struct smc_sock *smc)
	190	{
	191	struct smc_cdc_conn_state_flags *txflags =
	192	&smc->conn.local_tx_ctrl.conn_state_flags;
	193	struct smc_connection *conn = &smc->conn;
	194	struct sock *sk = &smc->sk;
	195	int old_state;
	196	long timeout;
	197	int rc = 0;
	198	int rc1 = 0;
	199
	200	timeout = current->flags & PF_EXITING ?
	201	0 : sock_flag(sk, SOCK_LINGER) ?
	202	sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
	203
	204	old_state = sk->sk_state;
	205	again:
	206	switch (sk->sk_state) {
	207	case SMC_INIT:
	208	sk->sk_state = SMC_CLOSED;
	209	break;
	210	case SMC_LISTEN:
	211	sk->sk_state = SMC_CLOSED;
	212	sk->sk_state_change(sk); /* wake up accept */
	213	if (smc->clcsock && smc->clcsock->sk) {
	214	smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
	215	smc->clcsock->sk->sk_user_data = NULL;
	216	rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
	217	}
	218	smc_close_cleanup_listen(sk);
	219	release_sock(sk);
	220	flush_work(&smc->tcp_listen_work);
	221	lock_sock(sk);
	222	break;
	223	case SMC_ACTIVE:
	224	smc_close_stream_wait(smc, timeout);
	225	release_sock(sk);
	226	cancel_delayed_work_sync(&conn->tx_work);
	227	lock_sock(sk);
	228	if (sk->sk_state == SMC_ACTIVE) {
	229	/* send close request */
	230	rc = smc_close_final(conn);
	231	sk->sk_state = SMC_PEERCLOSEWAIT1;
	232
	233	/* actively shutdown clcsock before peer close it,
	234	* prevent peer from entering TIME_WAIT state.
	235	*/
	236	if (smc->clcsock && smc->clcsock->sk) {
	237	rc1 = kernel_sock_shutdown(smc->clcsock,
	238	SHUT_RDWR);
	239	rc = rc ? rc : rc1;
	240	}
	241	} else {
	242	/* peer event has changed the state */
	243	goto again;
	244	}
	245	break;
	246	case SMC_APPFINCLOSEWAIT:
	247	/* socket already shutdown wr or both (active close) */
	248	if (txflags->peer_done_writing &&
	249	!smc_close_sent_any_close(conn)) {
	250	/* just shutdown wr done, send close request */
	251	rc = smc_close_final(conn);
	252	}
	253	sk->sk_state = SMC_CLOSED;
	254	break;
	255	case SMC_APPCLOSEWAIT1:
	256	case SMC_APPCLOSEWAIT2:
	257	if (!smc_cdc_rxed_any_close(conn))
	258	smc_close_stream_wait(smc, timeout);
	259	release_sock(sk);
	260	cancel_delayed_work_sync(&conn->tx_work);
	261	lock_sock(sk);
	262	if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
	263	sk->sk_state != SMC_APPCLOSEWAIT2)
	264	goto again;
	265	/* confirm close from peer */
	266	rc = smc_close_final(conn);
	267	if (smc_cdc_rxed_any_close(conn)) {
	268	/* peer has closed the socket already */
	269	sk->sk_state = SMC_CLOSED;
	270	sock_put(sk); /* postponed passive closing */
	271	} else {
	272	/* peer has just issued a shutdown write */
	273	sk->sk_state = SMC_PEERFINCLOSEWAIT;
	274	}
	275	break;
	276	case SMC_PEERCLOSEWAIT1:
	277	case SMC_PEERCLOSEWAIT2:
	278	if (txflags->peer_done_writing &&
	279	!smc_close_sent_any_close(conn)) {
	280	/* just shutdown wr done, send close request */
	281	rc = smc_close_final(conn);
	282	}
	283	/* peer sending PeerConnectionClosed will cause transition */
	284	break;
	285	case SMC_PEERFINCLOSEWAIT:
	286	/* peer sending PeerConnectionClosed will cause transition */
	287	break;
	288	case SMC_PROCESSABORT:
	289	rc = smc_close_abort(conn);
	290	sk->sk_state = SMC_CLOSED;
	291	break;
	292	case SMC_PEERABORTWAIT:
	293	sk->sk_state = SMC_CLOSED;
	294	break;
	295	case SMC_CLOSED:
	296	/* nothing to do, add tracing in future patch */
	297	break;
	298	}
	299
	300	if (old_state != sk->sk_state)
	301	sk->sk_state_change(sk);
	302	return rc;
	303	}
	304
	305	static void smc_close_passive_abort_received(struct smc_sock *smc)
	306	{
	307	struct smc_cdc_conn_state_flags *txflags =
	308	&smc->conn.local_tx_ctrl.conn_state_flags;
	309	struct sock *sk = &smc->sk;
	310
	311	switch (sk->sk_state) {
	312	case SMC_INIT:
	313	case SMC_ACTIVE:
	314	case SMC_APPCLOSEWAIT1:
	315	sk->sk_state = SMC_PROCESSABORT;
	316	sock_put(sk); /* passive closing */
	317	break;
	318	case SMC_APPFINCLOSEWAIT:
	319	sk->sk_state = SMC_PROCESSABORT;
	320	break;
	321	case SMC_PEERCLOSEWAIT1:
	322	case SMC_PEERCLOSEWAIT2:
	323	if (txflags->peer_done_writing &&
	324	!smc_close_sent_any_close(&smc->conn))
	325	/* just shutdown, but not yet closed locally */
	326	sk->sk_state = SMC_PROCESSABORT;
	327	else
	328	sk->sk_state = SMC_CLOSED;
	329	sock_put(sk); /* passive closing */
	330	break;
	331	case SMC_APPCLOSEWAIT2:
	332	case SMC_PEERFINCLOSEWAIT:
	333	sk->sk_state = SMC_CLOSED;
	334	sock_put(sk); /* passive closing */
	335	break;
	336	case SMC_PEERABORTWAIT:
	337	sk->sk_state = SMC_CLOSED;
	338	break;
	339	case SMC_PROCESSABORT:
	340	/* nothing to do, add tracing in future patch */
	341	break;
	342	}
	343	}
	344
	345	/* Either some kind of closing has been received: peer_conn_closed,
	346	* peer_conn_abort, or peer_done_writing
	347	* or the link group of the connection terminates abnormally.
	348	*/
	349	static void smc_close_passive_work(struct work_struct *work)
	350	{
	351	struct smc_connection *conn = container_of(work,
	352	struct smc_connection,
	353	close_work);
	354	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
	355	struct smc_cdc_conn_state_flags *rxflags;
	356	bool release_clcsock = false;
	357	struct sock *sk = &smc->sk;
	358	int old_state;
	359
	360	lock_sock(sk);
	361	old_state = sk->sk_state;
	362
	363	rxflags = &conn->local_rx_ctrl.conn_state_flags;
	364	if (rxflags->peer_conn_abort) {
	365	/* peer has not received all data */
	366	smc_close_passive_abort_received(smc);
	367	release_sock(&smc->sk);
	368	cancel_delayed_work_sync(&conn->tx_work);
	369	lock_sock(&smc->sk);
	370	goto wakeup;
	371	}
	372
	373	switch (sk->sk_state) {
	374	case SMC_INIT:
	375	sk->sk_state = SMC_APPCLOSEWAIT1;
	376	break;
	377	case SMC_ACTIVE:
	378	sk->sk_state = SMC_APPCLOSEWAIT1;
	379	/* postpone sock_put() for passive closing to cover
	380	* received SEND_SHUTDOWN as well
	381	*/
	382	break;
	383	case SMC_PEERCLOSEWAIT1:
	384	if (rxflags->peer_done_writing)
	385	sk->sk_state = SMC_PEERCLOSEWAIT2;
	386	fallthrough;
	387	/* to check for closing */
	388	case SMC_PEERCLOSEWAIT2:
	389	if (!smc_cdc_rxed_any_close(conn))
	390	break;
	391	if (sock_flag(sk, SOCK_DEAD) &&
	392	smc_close_sent_any_close(conn)) {
	393	/* smc_release has already been called locally */
	394	sk->sk_state = SMC_CLOSED;
	395	} else {
	396	/* just shutdown, but not yet closed locally */
	397	sk->sk_state = SMC_APPFINCLOSEWAIT;
	398	}
	399	sock_put(sk); /* passive closing */
	400	break;
	401	case SMC_PEERFINCLOSEWAIT:
	402	if (smc_cdc_rxed_any_close(conn)) {
	403	sk->sk_state = SMC_CLOSED;
	404	sock_put(sk); /* passive closing */
	405	}
	406	break;
	407	case SMC_APPCLOSEWAIT1:
	408	case SMC_APPCLOSEWAIT2:
	409	/* postpone sock_put() for passive closing to cover
	410	* received SEND_SHUTDOWN as well
	411	*/
	412	break;
	413	case SMC_APPFINCLOSEWAIT:
	414	case SMC_PEERABORTWAIT:
	415	case SMC_PROCESSABORT:
	416	case SMC_CLOSED:
	417	/* nothing to do, add tracing in future patch */
	418	break;
	419	}
	420
	421	wakeup:
	422	sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
	423	sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
	424
	425	if (old_state != sk->sk_state) {
	426	sk->sk_state_change(sk);
	427	if ((sk->sk_state == SMC_CLOSED) &&
	428	(sock_flag(sk, SOCK_DEAD) \|\| !sk->sk_socket)) {
	429	smc_conn_free(conn);
	430	if (smc->clcsock)
	431	release_clcsock = true;
	432	}
	433	}
	434	release_sock(sk);
	435	if (release_clcsock)
	436	smc_clcsock_release(smc);
	437	sock_put(sk); /* sock_hold done by schedulers of close_work */
	438	}
	439
	440	int smc_close_shutdown_write(struct smc_sock *smc)
	441	{
	442	struct smc_connection *conn = &smc->conn;
	443	struct sock *sk = &smc->sk;
	444	int old_state;
	445	long timeout;
	446	int rc = 0;
	447
	448	timeout = current->flags & PF_EXITING ?
	449	0 : sock_flag(sk, SOCK_LINGER) ?
	450	sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
	451
	452	old_state = sk->sk_state;
	453	again:
	454	switch (sk->sk_state) {
	455	case SMC_ACTIVE:
	456	smc_close_stream_wait(smc, timeout);
	457	release_sock(sk);
	458	cancel_delayed_work_sync(&conn->tx_work);
	459	lock_sock(sk);
	460	if (sk->sk_state != SMC_ACTIVE)
	461	goto again;
	462	/* send close wr request */
	463	rc = smc_close_wr(conn);
	464	sk->sk_state = SMC_PEERCLOSEWAIT1;
	465	break;
	466	case SMC_APPCLOSEWAIT1:
	467	/* passive close */
	468	if (!smc_cdc_rxed_any_close(conn))
	469	smc_close_stream_wait(smc, timeout);
	470	release_sock(sk);
	471	cancel_delayed_work_sync(&conn->tx_work);
	472	lock_sock(sk);
	473	if (sk->sk_state != SMC_APPCLOSEWAIT1)
	474	goto again;
	475	/* confirm close from peer */
	476	rc = smc_close_wr(conn);
	477	sk->sk_state = SMC_APPCLOSEWAIT2;
	478	break;
	479	case SMC_APPCLOSEWAIT2:
	480	case SMC_PEERFINCLOSEWAIT:
	481	case SMC_PEERCLOSEWAIT1:
	482	case SMC_PEERCLOSEWAIT2:
	483	case SMC_APPFINCLOSEWAIT:
	484	case SMC_PROCESSABORT:
	485	case SMC_PEERABORTWAIT:
	486	/* nothing to do, add tracing in future patch */
	487	break;
	488	}
	489
	490	if (old_state != sk->sk_state)
	491	sk->sk_state_change(sk);
	492	return rc;
	493	}
	494
	495	/* Initialize close properties on connection establishment. */
	496	void smc_close_init(struct smc_sock *smc)
	497	{
	498	INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
	499	}