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  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 */
 24void 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
 39static 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 */
 49static 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	/* Send out corked data remaining in sndbuf */
 61	smc_tx_pending(&smc->conn);
 62
 63	smc->wait_close_tx_prepared = 1;
 64	add_wait_queue(sk_sleep(sk), &wait);
 65	while (!signal_pending(current) && timeout) {
 66		int rc;
 67
 68		rc = sk_wait_event(sk, &timeout,
 69				   !smc_tx_prepared_sends(&smc->conn) ||
 70				   READ_ONCE(sk->sk_err) == ECONNABORTED ||
 71				   READ_ONCE(sk->sk_err) == ECONNRESET ||
 72				   smc->conn.killed,
 73				   &wait);
 74		if (rc)
 75			break;
 76	}
 77	remove_wait_queue(sk_sleep(sk), &wait);
 78	smc->wait_close_tx_prepared = 0;
 79}
 80
 81void smc_close_wake_tx_prepared(struct smc_sock *smc)
 82{
 83	if (smc->wait_close_tx_prepared)
 84		/* wake up socket closing */
 85		smc->sk.sk_state_change(&smc->sk);
 86}
 87
 88static int smc_close_wr(struct smc_connection *conn)
 89{
 90	conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;
 91
 92	return smc_cdc_get_slot_and_msg_send(conn);
 93}
 94
 95static int smc_close_final(struct smc_connection *conn)
 96{
 97	if (atomic_read(&conn->bytes_to_rcv))
 98		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 99	else
100		conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
101	if (conn->killed)
102		return -EPIPE;
103
104	return smc_cdc_get_slot_and_msg_send(conn);
105}
106
107int smc_close_abort(struct smc_connection *conn)
108{
109	conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
110
111	return smc_cdc_get_slot_and_msg_send(conn);
112}
113
114static void smc_close_cancel_work(struct smc_sock *smc)
115{
116	struct sock *sk = &smc->sk;
117
118	release_sock(sk);
119	if (cancel_work_sync(&smc->conn.close_work))
120		sock_put(sk);
121	cancel_delayed_work_sync(&smc->conn.tx_work);
122	lock_sock(sk);
123}
124
125/* terminate smc socket abnormally - active abort
126 * link group is terminated, i.e. RDMA communication no longer possible
127 */
128void smc_close_active_abort(struct smc_sock *smc)
129{
130	struct sock *sk = &smc->sk;
131	bool release_clcsock = false;
132
133	if (sk->sk_state != SMC_INIT && smc->clcsock && smc->clcsock->sk) {
134		sk->sk_err = ECONNABORTED;
135		if (smc->clcsock && smc->clcsock->sk)
136			tcp_abort(smc->clcsock->sk, ECONNABORTED);
137	}
138	switch (sk->sk_state) {
139	case SMC_ACTIVE:
140	case SMC_APPCLOSEWAIT1:
141	case SMC_APPCLOSEWAIT2:
142		sk->sk_state = SMC_PEERABORTWAIT;
143		smc_close_cancel_work(smc);
144		if (sk->sk_state != SMC_PEERABORTWAIT)
145			break;
146		sk->sk_state = SMC_CLOSED;
147		sock_put(sk); /* (postponed) passive closing */
148		break;
149	case SMC_PEERCLOSEWAIT1:
150	case SMC_PEERCLOSEWAIT2:
151	case SMC_PEERFINCLOSEWAIT:
152		sk->sk_state = SMC_PEERABORTWAIT;
153		smc_close_cancel_work(smc);
154		if (sk->sk_state != SMC_PEERABORTWAIT)
155			break;
156		sk->sk_state = SMC_CLOSED;
157		smc_conn_free(&smc->conn);
158		release_clcsock = true;
159		sock_put(sk); /* passive closing */
160		break;
161	case SMC_PROCESSABORT:
162	case SMC_APPFINCLOSEWAIT:
163		sk->sk_state = SMC_PEERABORTWAIT;
164		smc_close_cancel_work(smc);
165		if (sk->sk_state != SMC_PEERABORTWAIT)
166			break;
167		sk->sk_state = SMC_CLOSED;
168		smc_conn_free(&smc->conn);
169		release_clcsock = true;
170		break;
171	case SMC_INIT:
172	case SMC_PEERABORTWAIT:
173	case SMC_CLOSED:
174		break;
175	}
176
177	smc_sock_set_flag(sk, SOCK_DEAD);
178	sk->sk_state_change(sk);
179
180	if (release_clcsock) {
181		release_sock(sk);
182		smc_clcsock_release(smc);
183		lock_sock(sk);
184	}
185}
186
187static inline bool smc_close_sent_any_close(struct smc_connection *conn)
188{
189	return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
190	       conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
191}
192
193int smc_close_active(struct smc_sock *smc)
194{
195	struct smc_cdc_conn_state_flags *txflags =
196		&smc->conn.local_tx_ctrl.conn_state_flags;
197	struct smc_connection *conn = &smc->conn;
198	struct sock *sk = &smc->sk;
199	int old_state;
200	long timeout;
201	int rc = 0;
202	int rc1 = 0;
203
204	timeout = current->flags & PF_EXITING ?
205		  0 : sock_flag(sk, SOCK_LINGER) ?
206		      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
207
208	old_state = sk->sk_state;
209again:
210	switch (sk->sk_state) {
211	case SMC_INIT:
212		sk->sk_state = SMC_CLOSED;
213		break;
214	case SMC_LISTEN:
215		sk->sk_state = SMC_CLOSED;
216		sk->sk_state_change(sk); /* wake up accept */
217		if (smc->clcsock && smc->clcsock->sk) {
218			write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
219			smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
220					       &smc->clcsk_data_ready);
221			smc->clcsock->sk->sk_user_data = NULL;
222			write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
223			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
224		}
225		smc_close_cleanup_listen(sk);
226		release_sock(sk);
227		flush_work(&smc->tcp_listen_work);
228		lock_sock(sk);
229		break;
230	case SMC_ACTIVE:
231		smc_close_stream_wait(smc, timeout);
232		release_sock(sk);
233		cancel_delayed_work_sync(&conn->tx_work);
234		lock_sock(sk);
235		if (sk->sk_state == SMC_ACTIVE) {
236			/* send close request */
237			rc = smc_close_final(conn);
238			sk->sk_state = SMC_PEERCLOSEWAIT1;
239
240			/* actively shutdown clcsock before peer close it,
241			 * prevent peer from entering TIME_WAIT state.
242			 */
243			if (smc->clcsock && smc->clcsock->sk) {
244				rc1 = kernel_sock_shutdown(smc->clcsock,
245							   SHUT_RDWR);
246				rc = rc ? rc : rc1;
247			}
248		} else {
249			/* peer event has changed the state */
250			goto again;
251		}
252		break;
253	case SMC_APPFINCLOSEWAIT:
254		/* socket already shutdown wr or both (active close) */
255		if (txflags->peer_done_writing &&
256		    !smc_close_sent_any_close(conn)) {
257			/* just shutdown wr done, send close request */
258			rc = smc_close_final(conn);
259		}
260		sk->sk_state = SMC_CLOSED;
261		break;
262	case SMC_APPCLOSEWAIT1:
263	case SMC_APPCLOSEWAIT2:
264		if (!smc_cdc_rxed_any_close(conn))
265			smc_close_stream_wait(smc, timeout);
266		release_sock(sk);
267		cancel_delayed_work_sync(&conn->tx_work);
268		lock_sock(sk);
269		if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
270		    sk->sk_state != SMC_APPCLOSEWAIT2)
271			goto again;
272		/* confirm close from peer */
273		rc = smc_close_final(conn);
274		if (smc_cdc_rxed_any_close(conn)) {
275			/* peer has closed the socket already */
276			sk->sk_state = SMC_CLOSED;
277			sock_put(sk); /* postponed passive closing */
278		} else {
279			/* peer has just issued a shutdown write */
280			sk->sk_state = SMC_PEERFINCLOSEWAIT;
281		}
282		break;
283	case SMC_PEERCLOSEWAIT1:
284	case SMC_PEERCLOSEWAIT2:
285		if (txflags->peer_done_writing &&
286		    !smc_close_sent_any_close(conn)) {
287			/* just shutdown wr done, send close request */
288			rc = smc_close_final(conn);
289		}
290		/* peer sending PeerConnectionClosed will cause transition */
291		break;
292	case SMC_PEERFINCLOSEWAIT:
293		/* peer sending PeerConnectionClosed will cause transition */
294		break;
295	case SMC_PROCESSABORT:
296		rc = smc_close_abort(conn);
297		sk->sk_state = SMC_CLOSED;
298		break;
299	case SMC_PEERABORTWAIT:
300		sk->sk_state = SMC_CLOSED;
301		break;
302	case SMC_CLOSED:
303		/* nothing to do, add tracing in future patch */
304		break;
305	}
306
307	if (old_state != sk->sk_state)
308		sk->sk_state_change(sk);
309	return rc;
310}
311
312static void smc_close_passive_abort_received(struct smc_sock *smc)
313{
314	struct smc_cdc_conn_state_flags *txflags =
315		&smc->conn.local_tx_ctrl.conn_state_flags;
316	struct sock *sk = &smc->sk;
317
318	switch (sk->sk_state) {
319	case SMC_INIT:
320	case SMC_ACTIVE:
321	case SMC_APPCLOSEWAIT1:
322		sk->sk_state = SMC_PROCESSABORT;
323		sock_put(sk); /* passive closing */
324		break;
325	case SMC_APPFINCLOSEWAIT:
326		sk->sk_state = SMC_PROCESSABORT;
327		break;
328	case SMC_PEERCLOSEWAIT1:
329	case SMC_PEERCLOSEWAIT2:
330		if (txflags->peer_done_writing &&
331		    !smc_close_sent_any_close(&smc->conn))
332			/* just shutdown, but not yet closed locally */
333			sk->sk_state = SMC_PROCESSABORT;
334		else
335			sk->sk_state = SMC_CLOSED;
336		sock_put(sk); /* passive closing */
337		break;
338	case SMC_APPCLOSEWAIT2:
339	case SMC_PEERFINCLOSEWAIT:
340		sk->sk_state = SMC_CLOSED;
341		sock_put(sk); /* passive closing */
342		break;
343	case SMC_PEERABORTWAIT:
344		sk->sk_state = SMC_CLOSED;
345		break;
346	case SMC_PROCESSABORT:
347	/* nothing to do, add tracing in future patch */
348		break;
349	}
350}
351
352/* Either some kind of closing has been received: peer_conn_closed,
353 * peer_conn_abort, or peer_done_writing
354 * or the link group of the connection terminates abnormally.
355 */
356static void smc_close_passive_work(struct work_struct *work)
357{
358	struct smc_connection *conn = container_of(work,
359						   struct smc_connection,
360						   close_work);
361	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
362	struct smc_cdc_conn_state_flags *rxflags;
363	bool release_clcsock = false;
364	struct sock *sk = &smc->sk;
365	int old_state;
366
367	lock_sock(sk);
368	old_state = sk->sk_state;
369
370	rxflags = &conn->local_rx_ctrl.conn_state_flags;
371	if (rxflags->peer_conn_abort) {
372		/* peer has not received all data */
373		smc_close_passive_abort_received(smc);
374		release_sock(sk);
375		cancel_delayed_work_sync(&conn->tx_work);
376		lock_sock(sk);
377		goto wakeup;
378	}
379
380	switch (sk->sk_state) {
381	case SMC_INIT:
382		sk->sk_state = SMC_APPCLOSEWAIT1;
383		break;
384	case SMC_ACTIVE:
385		sk->sk_state = SMC_APPCLOSEWAIT1;
386		/* postpone sock_put() for passive closing to cover
387		 * received SEND_SHUTDOWN as well
388		 */
389		break;
390	case SMC_PEERCLOSEWAIT1:
391		if (rxflags->peer_done_writing)
392			sk->sk_state = SMC_PEERCLOSEWAIT2;
393		fallthrough;
394		/* to check for closing */
395	case SMC_PEERCLOSEWAIT2:
396		if (!smc_cdc_rxed_any_close(conn))
397			break;
398		if (sock_flag(sk, SOCK_DEAD) &&
399		    smc_close_sent_any_close(conn)) {
400			/* smc_release has already been called locally */
401			sk->sk_state = SMC_CLOSED;
402		} else {
403			/* just shutdown, but not yet closed locally */
404			sk->sk_state = SMC_APPFINCLOSEWAIT;
405		}
406		sock_put(sk); /* passive closing */
407		break;
408	case SMC_PEERFINCLOSEWAIT:
409		if (smc_cdc_rxed_any_close(conn)) {
410			sk->sk_state = SMC_CLOSED;
411			sock_put(sk); /* passive closing */
412		}
413		break;
414	case SMC_APPCLOSEWAIT1:
415	case SMC_APPCLOSEWAIT2:
416		/* postpone sock_put() for passive closing to cover
417		 * received SEND_SHUTDOWN as well
418		 */
419		break;
420	case SMC_APPFINCLOSEWAIT:
421	case SMC_PEERABORTWAIT:
422	case SMC_PROCESSABORT:
423	case SMC_CLOSED:
424		/* nothing to do, add tracing in future patch */
425		break;
426	}
427
428wakeup:
429	sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
430	sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
431
432	if (old_state != sk->sk_state) {
433		sk->sk_state_change(sk);
434		if ((sk->sk_state == SMC_CLOSED) &&
435		    (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
436			smc_conn_free(conn);
437			if (smc->clcsock)
438				release_clcsock = true;
439		}
440	}
441	release_sock(sk);
442	if (release_clcsock)
443		smc_clcsock_release(smc);
444	sock_put(sk); /* sock_hold done by schedulers of close_work */
445}
446
447int smc_close_shutdown_write(struct smc_sock *smc)
448{
449	struct smc_connection *conn = &smc->conn;
450	struct sock *sk = &smc->sk;
451	int old_state;
452	long timeout;
453	int rc = 0;
454
455	timeout = current->flags & PF_EXITING ?
456		  0 : sock_flag(sk, SOCK_LINGER) ?
457		      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
458
459	old_state = sk->sk_state;
460again:
461	switch (sk->sk_state) {
462	case SMC_ACTIVE:
463		smc_close_stream_wait(smc, timeout);
464		release_sock(sk);
465		cancel_delayed_work_sync(&conn->tx_work);
466		lock_sock(sk);
467		if (sk->sk_state != SMC_ACTIVE)
468			goto again;
469		/* send close wr request */
470		rc = smc_close_wr(conn);
471		sk->sk_state = SMC_PEERCLOSEWAIT1;
472		break;
473	case SMC_APPCLOSEWAIT1:
474		/* passive close */
475		if (!smc_cdc_rxed_any_close(conn))
476			smc_close_stream_wait(smc, timeout);
477		release_sock(sk);
478		cancel_delayed_work_sync(&conn->tx_work);
479		lock_sock(sk);
480		if (sk->sk_state != SMC_APPCLOSEWAIT1)
481			goto again;
482		/* confirm close from peer */
483		rc = smc_close_wr(conn);
484		sk->sk_state = SMC_APPCLOSEWAIT2;
485		break;
486	case SMC_APPCLOSEWAIT2:
487	case SMC_PEERFINCLOSEWAIT:
488	case SMC_PEERCLOSEWAIT1:
489	case SMC_PEERCLOSEWAIT2:
490	case SMC_APPFINCLOSEWAIT:
491	case SMC_PROCESSABORT:
492	case SMC_PEERABORTWAIT:
493		/* nothing to do, add tracing in future patch */
494		break;
495	}
496
497	if (old_state != sk->sk_state)
498		sk->sk_state_change(sk);
499	return rc;
500}
501
502/* Initialize close properties on connection establishment. */
503void smc_close_init(struct smc_sock *smc)
504{
505	INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
506}
  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 */
 24void 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
 39static 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 */
 49static 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	/* Send out corked data remaining in sndbuf */
 61	smc_tx_pending(&smc->conn);
 62
 63	smc->wait_close_tx_prepared = 1;
 64	add_wait_queue(sk_sleep(sk), &wait);
 65	while (!signal_pending(current) && timeout) {
 66		int rc;
 67
 68		rc = sk_wait_event(sk, &timeout,
 69				   !smc_tx_prepared_sends(&smc->conn) ||
 70				   sk->sk_err == ECONNABORTED ||
 71				   sk->sk_err == ECONNRESET ||
 72				   smc->conn.killed,
 73				   &wait);
 74		if (rc)
 75			break;
 76	}
 77	remove_wait_queue(sk_sleep(sk), &wait);
 78	smc->wait_close_tx_prepared = 0;
 79}
 80
 81void smc_close_wake_tx_prepared(struct smc_sock *smc)
 82{
 83	if (smc->wait_close_tx_prepared)
 84		/* wake up socket closing */
 85		smc->sk.sk_state_change(&smc->sk);
 86}
 87
 88static int smc_close_wr(struct smc_connection *conn)
 89{
 90	conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;
 91
 92	return smc_cdc_get_slot_and_msg_send(conn);
 93}
 94
 95static int smc_close_final(struct smc_connection *conn)
 96{
 97	if (atomic_read(&conn->bytes_to_rcv))
 98		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 99	else
100		conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
101	if (conn->killed)
102		return -EPIPE;
103
104	return smc_cdc_get_slot_and_msg_send(conn);
105}
106
107int smc_close_abort(struct smc_connection *conn)
108{
109	conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
110
111	return smc_cdc_get_slot_and_msg_send(conn);
112}
113
114static void smc_close_cancel_work(struct smc_sock *smc)
115{
116	struct sock *sk = &smc->sk;
117
118	release_sock(sk);
119	cancel_work_sync(&smc->conn.close_work);
 
120	cancel_delayed_work_sync(&smc->conn.tx_work);
121	lock_sock(sk);
122}
123
124/* terminate smc socket abnormally - active abort
125 * link group is terminated, i.e. RDMA communication no longer possible
126 */
127void smc_close_active_abort(struct smc_sock *smc)
128{
129	struct sock *sk = &smc->sk;
130	bool release_clcsock = false;
131
132	if (sk->sk_state != SMC_INIT && smc->clcsock && smc->clcsock->sk) {
133		sk->sk_err = ECONNABORTED;
134		if (smc->clcsock && smc->clcsock->sk)
135			tcp_abort(smc->clcsock->sk, ECONNABORTED);
136	}
137	switch (sk->sk_state) {
138	case SMC_ACTIVE:
139	case SMC_APPCLOSEWAIT1:
140	case SMC_APPCLOSEWAIT2:
141		sk->sk_state = SMC_PEERABORTWAIT;
142		smc_close_cancel_work(smc);
143		if (sk->sk_state != SMC_PEERABORTWAIT)
144			break;
145		sk->sk_state = SMC_CLOSED;
146		sock_put(sk); /* (postponed) passive closing */
147		break;
148	case SMC_PEERCLOSEWAIT1:
149	case SMC_PEERCLOSEWAIT2:
150	case SMC_PEERFINCLOSEWAIT:
151		sk->sk_state = SMC_PEERABORTWAIT;
152		smc_close_cancel_work(smc);
153		if (sk->sk_state != SMC_PEERABORTWAIT)
154			break;
155		sk->sk_state = SMC_CLOSED;
156		smc_conn_free(&smc->conn);
157		release_clcsock = true;
158		sock_put(sk); /* passive closing */
159		break;
160	case SMC_PROCESSABORT:
161	case SMC_APPFINCLOSEWAIT:
162		sk->sk_state = SMC_PEERABORTWAIT;
163		smc_close_cancel_work(smc);
164		if (sk->sk_state != SMC_PEERABORTWAIT)
165			break;
166		sk->sk_state = SMC_CLOSED;
167		smc_conn_free(&smc->conn);
168		release_clcsock = true;
169		break;
170	case SMC_INIT:
171	case SMC_PEERABORTWAIT:
172	case SMC_CLOSED:
173		break;
174	}
175
176	sock_set_flag(sk, SOCK_DEAD);
177	sk->sk_state_change(sk);
178
179	if (release_clcsock) {
180		release_sock(sk);
181		smc_clcsock_release(smc);
182		lock_sock(sk);
183	}
184}
185
186static inline bool smc_close_sent_any_close(struct smc_connection *conn)
187{
188	return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
189	       conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
190}
191
192int smc_close_active(struct smc_sock *smc)
193{
194	struct smc_cdc_conn_state_flags *txflags =
195		&smc->conn.local_tx_ctrl.conn_state_flags;
196	struct smc_connection *conn = &smc->conn;
197	struct sock *sk = &smc->sk;
198	int old_state;
199	long timeout;
200	int rc = 0;
201	int rc1 = 0;
202
203	timeout = current->flags & PF_EXITING ?
204		  0 : sock_flag(sk, SOCK_LINGER) ?
205		      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
206
207	old_state = sk->sk_state;
208again:
209	switch (sk->sk_state) {
210	case SMC_INIT:
211		sk->sk_state = SMC_CLOSED;
212		break;
213	case SMC_LISTEN:
214		sk->sk_state = SMC_CLOSED;
215		sk->sk_state_change(sk); /* wake up accept */
216		if (smc->clcsock && smc->clcsock->sk) {
217			write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
218			smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
219					       &smc->clcsk_data_ready);
220			smc->clcsock->sk->sk_user_data = NULL;
221			write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
222			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
223		}
224		smc_close_cleanup_listen(sk);
225		release_sock(sk);
226		flush_work(&smc->tcp_listen_work);
227		lock_sock(sk);
228		break;
229	case SMC_ACTIVE:
230		smc_close_stream_wait(smc, timeout);
231		release_sock(sk);
232		cancel_delayed_work_sync(&conn->tx_work);
233		lock_sock(sk);
234		if (sk->sk_state == SMC_ACTIVE) {
235			/* send close request */
236			rc = smc_close_final(conn);
237			sk->sk_state = SMC_PEERCLOSEWAIT1;
238
239			/* actively shutdown clcsock before peer close it,
240			 * prevent peer from entering TIME_WAIT state.
241			 */
242			if (smc->clcsock && smc->clcsock->sk) {
243				rc1 = kernel_sock_shutdown(smc->clcsock,
244							   SHUT_RDWR);
245				rc = rc ? rc : rc1;
246			}
247		} else {
248			/* peer event has changed the state */
249			goto again;
250		}
251		break;
252	case SMC_APPFINCLOSEWAIT:
253		/* socket already shutdown wr or both (active close) */
254		if (txflags->peer_done_writing &&
255		    !smc_close_sent_any_close(conn)) {
256			/* just shutdown wr done, send close request */
257			rc = smc_close_final(conn);
258		}
259		sk->sk_state = SMC_CLOSED;
260		break;
261	case SMC_APPCLOSEWAIT1:
262	case SMC_APPCLOSEWAIT2:
263		if (!smc_cdc_rxed_any_close(conn))
264			smc_close_stream_wait(smc, timeout);
265		release_sock(sk);
266		cancel_delayed_work_sync(&conn->tx_work);
267		lock_sock(sk);
268		if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
269		    sk->sk_state != SMC_APPCLOSEWAIT2)
270			goto again;
271		/* confirm close from peer */
272		rc = smc_close_final(conn);
273		if (smc_cdc_rxed_any_close(conn)) {
274			/* peer has closed the socket already */
275			sk->sk_state = SMC_CLOSED;
276			sock_put(sk); /* postponed passive closing */
277		} else {
278			/* peer has just issued a shutdown write */
279			sk->sk_state = SMC_PEERFINCLOSEWAIT;
280		}
281		break;
282	case SMC_PEERCLOSEWAIT1:
283	case SMC_PEERCLOSEWAIT2:
284		if (txflags->peer_done_writing &&
285		    !smc_close_sent_any_close(conn)) {
286			/* just shutdown wr done, send close request */
287			rc = smc_close_final(conn);
288		}
289		/* peer sending PeerConnectionClosed will cause transition */
290		break;
291	case SMC_PEERFINCLOSEWAIT:
292		/* peer sending PeerConnectionClosed will cause transition */
293		break;
294	case SMC_PROCESSABORT:
295		rc = smc_close_abort(conn);
296		sk->sk_state = SMC_CLOSED;
297		break;
298	case SMC_PEERABORTWAIT:
299		sk->sk_state = SMC_CLOSED;
300		break;
301	case SMC_CLOSED:
302		/* nothing to do, add tracing in future patch */
303		break;
304	}
305
306	if (old_state != sk->sk_state)
307		sk->sk_state_change(sk);
308	return rc;
309}
310
311static void smc_close_passive_abort_received(struct smc_sock *smc)
312{
313	struct smc_cdc_conn_state_flags *txflags =
314		&smc->conn.local_tx_ctrl.conn_state_flags;
315	struct sock *sk = &smc->sk;
316
317	switch (sk->sk_state) {
318	case SMC_INIT:
319	case SMC_ACTIVE:
320	case SMC_APPCLOSEWAIT1:
321		sk->sk_state = SMC_PROCESSABORT;
322		sock_put(sk); /* passive closing */
323		break;
324	case SMC_APPFINCLOSEWAIT:
325		sk->sk_state = SMC_PROCESSABORT;
326		break;
327	case SMC_PEERCLOSEWAIT1:
328	case SMC_PEERCLOSEWAIT2:
329		if (txflags->peer_done_writing &&
330		    !smc_close_sent_any_close(&smc->conn))
331			/* just shutdown, but not yet closed locally */
332			sk->sk_state = SMC_PROCESSABORT;
333		else
334			sk->sk_state = SMC_CLOSED;
335		sock_put(sk); /* passive closing */
336		break;
337	case SMC_APPCLOSEWAIT2:
338	case SMC_PEERFINCLOSEWAIT:
339		sk->sk_state = SMC_CLOSED;
340		sock_put(sk); /* passive closing */
341		break;
342	case SMC_PEERABORTWAIT:
343		sk->sk_state = SMC_CLOSED;
344		break;
345	case SMC_PROCESSABORT:
346	/* nothing to do, add tracing in future patch */
347		break;
348	}
349}
350
351/* Either some kind of closing has been received: peer_conn_closed,
352 * peer_conn_abort, or peer_done_writing
353 * or the link group of the connection terminates abnormally.
354 */
355static void smc_close_passive_work(struct work_struct *work)
356{
357	struct smc_connection *conn = container_of(work,
358						   struct smc_connection,
359						   close_work);
360	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
361	struct smc_cdc_conn_state_flags *rxflags;
362	bool release_clcsock = false;
363	struct sock *sk = &smc->sk;
364	int old_state;
365
366	lock_sock(sk);
367	old_state = sk->sk_state;
368
369	rxflags = &conn->local_rx_ctrl.conn_state_flags;
370	if (rxflags->peer_conn_abort) {
371		/* peer has not received all data */
372		smc_close_passive_abort_received(smc);
373		release_sock(sk);
374		cancel_delayed_work_sync(&conn->tx_work);
375		lock_sock(sk);
376		goto wakeup;
377	}
378
379	switch (sk->sk_state) {
380	case SMC_INIT:
381		sk->sk_state = SMC_APPCLOSEWAIT1;
382		break;
383	case SMC_ACTIVE:
384		sk->sk_state = SMC_APPCLOSEWAIT1;
385		/* postpone sock_put() for passive closing to cover
386		 * received SEND_SHUTDOWN as well
387		 */
388		break;
389	case SMC_PEERCLOSEWAIT1:
390		if (rxflags->peer_done_writing)
391			sk->sk_state = SMC_PEERCLOSEWAIT2;
392		fallthrough;
393		/* to check for closing */
394	case SMC_PEERCLOSEWAIT2:
395		if (!smc_cdc_rxed_any_close(conn))
396			break;
397		if (sock_flag(sk, SOCK_DEAD) &&
398		    smc_close_sent_any_close(conn)) {
399			/* smc_release has already been called locally */
400			sk->sk_state = SMC_CLOSED;
401		} else {
402			/* just shutdown, but not yet closed locally */
403			sk->sk_state = SMC_APPFINCLOSEWAIT;
404		}
405		sock_put(sk); /* passive closing */
406		break;
407	case SMC_PEERFINCLOSEWAIT:
408		if (smc_cdc_rxed_any_close(conn)) {
409			sk->sk_state = SMC_CLOSED;
410			sock_put(sk); /* passive closing */
411		}
412		break;
413	case SMC_APPCLOSEWAIT1:
414	case SMC_APPCLOSEWAIT2:
415		/* postpone sock_put() for passive closing to cover
416		 * received SEND_SHUTDOWN as well
417		 */
418		break;
419	case SMC_APPFINCLOSEWAIT:
420	case SMC_PEERABORTWAIT:
421	case SMC_PROCESSABORT:
422	case SMC_CLOSED:
423		/* nothing to do, add tracing in future patch */
424		break;
425	}
426
427wakeup:
428	sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
429	sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
430
431	if (old_state != sk->sk_state) {
432		sk->sk_state_change(sk);
433		if ((sk->sk_state == SMC_CLOSED) &&
434		    (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
435			smc_conn_free(conn);
436			if (smc->clcsock)
437				release_clcsock = true;
438		}
439	}
440	release_sock(sk);
441	if (release_clcsock)
442		smc_clcsock_release(smc);
443	sock_put(sk); /* sock_hold done by schedulers of close_work */
444}
445
446int smc_close_shutdown_write(struct smc_sock *smc)
447{
448	struct smc_connection *conn = &smc->conn;
449	struct sock *sk = &smc->sk;
450	int old_state;
451	long timeout;
452	int rc = 0;
453
454	timeout = current->flags & PF_EXITING ?
455		  0 : sock_flag(sk, SOCK_LINGER) ?
456		      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
457
458	old_state = sk->sk_state;
459again:
460	switch (sk->sk_state) {
461	case SMC_ACTIVE:
462		smc_close_stream_wait(smc, timeout);
463		release_sock(sk);
464		cancel_delayed_work_sync(&conn->tx_work);
465		lock_sock(sk);
466		if (sk->sk_state != SMC_ACTIVE)
467			goto again;
468		/* send close wr request */
469		rc = smc_close_wr(conn);
470		sk->sk_state = SMC_PEERCLOSEWAIT1;
471		break;
472	case SMC_APPCLOSEWAIT1:
473		/* passive close */
474		if (!smc_cdc_rxed_any_close(conn))
475			smc_close_stream_wait(smc, timeout);
476		release_sock(sk);
477		cancel_delayed_work_sync(&conn->tx_work);
478		lock_sock(sk);
479		if (sk->sk_state != SMC_APPCLOSEWAIT1)
480			goto again;
481		/* confirm close from peer */
482		rc = smc_close_wr(conn);
483		sk->sk_state = SMC_APPCLOSEWAIT2;
484		break;
485	case SMC_APPCLOSEWAIT2:
486	case SMC_PEERFINCLOSEWAIT:
487	case SMC_PEERCLOSEWAIT1:
488	case SMC_PEERCLOSEWAIT2:
489	case SMC_APPFINCLOSEWAIT:
490	case SMC_PROCESSABORT:
491	case SMC_PEERABORTWAIT:
492		/* nothing to do, add tracing in future patch */
493		break;
494	}
495
496	if (old_state != sk->sk_state)
497		sk->sk_state_change(sk);
498	return rc;
499}
500
501/* Initialize close properties on connection establishment. */
502void smc_close_init(struct smc_sock *smc)
503{
504	INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
505}