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v6.8
  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}
v4.17
  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
 17#include "smc.h"
 18#include "smc_tx.h"
 19#include "smc_cdc.h"
 20#include "smc_close.h"
 21
 22#define SMC_CLOSE_WAIT_LISTEN_CLCSOCK_TIME	(5 * HZ)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 23
 24static void smc_close_cleanup_listen(struct sock *parent)
 25{
 26	struct sock *sk;
 27
 28	/* Close non-accepted connections */
 29	while ((sk = smc_accept_dequeue(parent, NULL)))
 30		smc_close_non_accepted(sk);
 31}
 32
 33/* wait for sndbuf data being transmitted */
 34static void smc_close_stream_wait(struct smc_sock *smc, long timeout)
 35{
 36	DEFINE_WAIT_FUNC(wait, woken_wake_function);
 37	struct sock *sk = &smc->sk;
 38
 39	if (!timeout)
 40		return;
 41
 42	if (!smc_tx_prepared_sends(&smc->conn))
 43		return;
 44
 
 
 
 45	smc->wait_close_tx_prepared = 1;
 46	add_wait_queue(sk_sleep(sk), &wait);
 47	while (!signal_pending(current) && timeout) {
 48		int rc;
 49
 50		rc = sk_wait_event(sk, &timeout,
 51				   !smc_tx_prepared_sends(&smc->conn) ||
 52				   (sk->sk_err == ECONNABORTED) ||
 53				   (sk->sk_err == ECONNRESET),
 
 54				   &wait);
 55		if (rc)
 56			break;
 57	}
 58	remove_wait_queue(sk_sleep(sk), &wait);
 59	smc->wait_close_tx_prepared = 0;
 60}
 61
 62void smc_close_wake_tx_prepared(struct smc_sock *smc)
 63{
 64	if (smc->wait_close_tx_prepared)
 65		/* wake up socket closing */
 66		smc->sk.sk_state_change(&smc->sk);
 67}
 68
 69static int smc_close_wr(struct smc_connection *conn)
 70{
 71	conn->local_tx_ctrl.conn_state_flags.peer_done_writing = 1;
 72
 73	return smc_cdc_get_slot_and_msg_send(conn);
 74}
 75
 76static int smc_close_final(struct smc_connection *conn)
 77{
 78	if (atomic_read(&conn->bytes_to_rcv))
 79		conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 80	else
 81		conn->local_tx_ctrl.conn_state_flags.peer_conn_closed = 1;
 
 
 82
 83	return smc_cdc_get_slot_and_msg_send(conn);
 84}
 85
 86static int smc_close_abort(struct smc_connection *conn)
 87{
 88	conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
 89
 90	return smc_cdc_get_slot_and_msg_send(conn);
 91}
 92
 
 
 
 
 
 
 
 
 
 
 
 93/* terminate smc socket abnormally - active abort
 94 * link group is terminated, i.e. RDMA communication no longer possible
 95 */
 96static void smc_close_active_abort(struct smc_sock *smc)
 97{
 98	struct sock *sk = &smc->sk;
 
 99
100	struct smc_cdc_conn_state_flags *txflags =
101		&smc->conn.local_tx_ctrl.conn_state_flags;
102
103	sk->sk_err = ECONNABORTED;
104	if (smc->clcsock && smc->clcsock->sk) {
105		smc->clcsock->sk->sk_err = ECONNABORTED;
106		smc->clcsock->sk->sk_state_change(smc->clcsock->sk);
107	}
108	switch (sk->sk_state) {
109	case SMC_INIT:
110	case SMC_ACTIVE:
111		sk->sk_state = SMC_PEERABORTWAIT;
112		release_sock(sk);
113		cancel_delayed_work_sync(&smc->conn.tx_work);
114		lock_sock(sk);
115		sock_put(sk); /* passive closing */
116		break;
117	case SMC_APPCLOSEWAIT1:
118	case SMC_APPCLOSEWAIT2:
119		if (!smc_cdc_rxed_any_close(&smc->conn))
120			sk->sk_state = SMC_PEERABORTWAIT;
121		else
122			sk->sk_state = SMC_CLOSED;
123		release_sock(sk);
124		cancel_delayed_work_sync(&smc->conn.tx_work);
125		lock_sock(sk);
126		break;
127	case SMC_PEERCLOSEWAIT1:
128	case SMC_PEERCLOSEWAIT2:
129		if (!txflags->peer_conn_closed) {
130			/* just SHUTDOWN_SEND done */
131			sk->sk_state = SMC_PEERABORTWAIT;
132		} else {
133			sk->sk_state = SMC_CLOSED;
134		}
 
 
135		sock_put(sk); /* passive closing */
136		break;
137	case SMC_PROCESSABORT:
138	case SMC_APPFINCLOSEWAIT:
 
 
 
 
139		sk->sk_state = SMC_CLOSED;
 
 
140		break;
141	case SMC_PEERFINCLOSEWAIT:
142		sock_put(sk); /* passive closing */
143		break;
144	case SMC_PEERABORTWAIT:
145	case SMC_CLOSED:
146		break;
147	}
148
149	sock_set_flag(sk, SOCK_DEAD);
150	sk->sk_state_change(sk);
 
 
 
 
 
 
151}
152
153static inline bool smc_close_sent_any_close(struct smc_connection *conn)
154{
155	return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
156	       conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
157}
158
159int smc_close_active(struct smc_sock *smc)
160{
161	struct smc_cdc_conn_state_flags *txflags =
162		&smc->conn.local_tx_ctrl.conn_state_flags;
163	struct smc_connection *conn = &smc->conn;
164	struct sock *sk = &smc->sk;
165	int old_state;
166	long timeout;
167	int rc = 0;
 
168
169	timeout = current->flags & PF_EXITING ?
170		  0 : sock_flag(sk, SOCK_LINGER) ?
171		      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
172
173	old_state = sk->sk_state;
174again:
175	switch (sk->sk_state) {
176	case SMC_INIT:
177		sk->sk_state = SMC_CLOSED;
178		break;
179	case SMC_LISTEN:
180		sk->sk_state = SMC_CLOSED;
181		sk->sk_state_change(sk); /* wake up accept */
182		if (smc->clcsock && smc->clcsock->sk) {
 
 
 
 
 
183			rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
184			/* wake up kernel_accept of smc_tcp_listen_worker */
185			smc->clcsock->sk->sk_data_ready(smc->clcsock->sk);
186		}
187		smc_close_cleanup_listen(sk);
188		release_sock(sk);
189		flush_work(&smc->tcp_listen_work);
190		lock_sock(sk);
191		break;
192	case SMC_ACTIVE:
193		smc_close_stream_wait(smc, timeout);
194		release_sock(sk);
195		cancel_delayed_work_sync(&conn->tx_work);
196		lock_sock(sk);
197		if (sk->sk_state == SMC_ACTIVE) {
198			/* send close request */
199			rc = smc_close_final(conn);
200			if (rc)
201				break;
202			sk->sk_state = SMC_PEERCLOSEWAIT1;
 
 
 
 
 
 
 
 
 
203		} else {
204			/* peer event has changed the state */
205			goto again;
206		}
207		break;
208	case SMC_APPFINCLOSEWAIT:
209		/* socket already shutdown wr or both (active close) */
210		if (txflags->peer_done_writing &&
211		    !smc_close_sent_any_close(conn)) {
212			/* just shutdown wr done, send close request */
213			rc = smc_close_final(conn);
214			if (rc)
215				break;
216		}
217		sk->sk_state = SMC_CLOSED;
218		break;
219	case SMC_APPCLOSEWAIT1:
220	case SMC_APPCLOSEWAIT2:
221		if (!smc_cdc_rxed_any_close(conn))
222			smc_close_stream_wait(smc, timeout);
223		release_sock(sk);
224		cancel_delayed_work_sync(&conn->tx_work);
225		lock_sock(sk);
226		if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
227		    sk->sk_state != SMC_APPCLOSEWAIT2)
228			goto again;
229		/* confirm close from peer */
230		rc = smc_close_final(conn);
231		if (rc)
232			break;
233		if (smc_cdc_rxed_any_close(conn)) {
234			/* peer has closed the socket already */
235			sk->sk_state = SMC_CLOSED;
236			sock_put(sk); /* postponed passive closing */
237		} else {
238			/* peer has just issued a shutdown write */
239			sk->sk_state = SMC_PEERFINCLOSEWAIT;
240		}
241		break;
242	case SMC_PEERCLOSEWAIT1:
243	case SMC_PEERCLOSEWAIT2:
244		if (txflags->peer_done_writing &&
245		    !smc_close_sent_any_close(conn)) {
246			/* just shutdown wr done, send close request */
247			rc = smc_close_final(conn);
248			if (rc)
249				break;
250		}
251		/* peer sending PeerConnectionClosed will cause transition */
252		break;
253	case SMC_PEERFINCLOSEWAIT:
254		/* peer sending PeerConnectionClosed will cause transition */
255		break;
256	case SMC_PROCESSABORT:
257		smc_close_abort(conn);
258		sk->sk_state = SMC_CLOSED;
259		break;
260	case SMC_PEERABORTWAIT:
 
 
261	case SMC_CLOSED:
262		/* nothing to do, add tracing in future patch */
263		break;
264	}
265
266	if (old_state != sk->sk_state)
267		sk->sk_state_change(sk);
268	return rc;
269}
270
271static void smc_close_passive_abort_received(struct smc_sock *smc)
272{
273	struct smc_cdc_conn_state_flags *txflags =
274		&smc->conn.local_tx_ctrl.conn_state_flags;
275	struct sock *sk = &smc->sk;
276
277	switch (sk->sk_state) {
278	case SMC_INIT:
279	case SMC_ACTIVE:
280	case SMC_APPCLOSEWAIT1:
281		sk->sk_state = SMC_PROCESSABORT;
282		sock_put(sk); /* passive closing */
283		break;
284	case SMC_APPFINCLOSEWAIT:
285		sk->sk_state = SMC_PROCESSABORT;
286		break;
287	case SMC_PEERCLOSEWAIT1:
288	case SMC_PEERCLOSEWAIT2:
289		if (txflags->peer_done_writing &&
290		    !smc_close_sent_any_close(&smc->conn))
291			/* just shutdown, but not yet closed locally */
292			sk->sk_state = SMC_PROCESSABORT;
293		else
294			sk->sk_state = SMC_CLOSED;
295		sock_put(sk); /* passive closing */
296		break;
297	case SMC_APPCLOSEWAIT2:
298	case SMC_PEERFINCLOSEWAIT:
299		sk->sk_state = SMC_CLOSED;
300		sock_put(sk); /* passive closing */
301		break;
302	case SMC_PEERABORTWAIT:
303		sk->sk_state = SMC_CLOSED;
304		break;
305	case SMC_PROCESSABORT:
306	/* nothing to do, add tracing in future patch */
307		break;
308	}
309}
310
311/* Either some kind of closing has been received: peer_conn_closed,
312 * peer_conn_abort, or peer_done_writing
313 * or the link group of the connection terminates abnormally.
314 */
315static void smc_close_passive_work(struct work_struct *work)
316{
317	struct smc_connection *conn = container_of(work,
318						   struct smc_connection,
319						   close_work);
320	struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
321	struct smc_cdc_conn_state_flags *rxflags;
 
322	struct sock *sk = &smc->sk;
323	int old_state;
324
325	lock_sock(sk);
326	old_state = sk->sk_state;
327
328	if (!conn->alert_token_local) {
329		/* abnormal termination */
330		smc_close_active_abort(smc);
331		goto wakeup;
332	}
333
334	rxflags = &conn->local_rx_ctrl.conn_state_flags;
335	if (rxflags->peer_conn_abort) {
336		/* peer has not received all data */
337		smc_close_passive_abort_received(smc);
338		release_sock(&smc->sk);
339		cancel_delayed_work_sync(&conn->tx_work);
340		lock_sock(&smc->sk);
341		goto wakeup;
342	}
343
344	switch (sk->sk_state) {
345	case SMC_INIT:
346		if (atomic_read(&conn->bytes_to_rcv) ||
347		    (rxflags->peer_done_writing &&
348		     !smc_cdc_rxed_any_close(conn))) {
349			sk->sk_state = SMC_APPCLOSEWAIT1;
350		} else {
351			sk->sk_state = SMC_CLOSED;
352			sock_put(sk); /* passive closing */
353		}
354		break;
355	case SMC_ACTIVE:
356		sk->sk_state = SMC_APPCLOSEWAIT1;
357		/* postpone sock_put() for passive closing to cover
358		 * received SEND_SHUTDOWN as well
359		 */
360		break;
361	case SMC_PEERCLOSEWAIT1:
362		if (rxflags->peer_done_writing)
363			sk->sk_state = SMC_PEERCLOSEWAIT2;
364		/* fall through */
365		/* to check for closing */
366	case SMC_PEERCLOSEWAIT2:
367		if (!smc_cdc_rxed_any_close(conn))
368			break;
369		if (sock_flag(sk, SOCK_DEAD) &&
370		    smc_close_sent_any_close(conn)) {
371			/* smc_release has already been called locally */
372			sk->sk_state = SMC_CLOSED;
373		} else {
374			/* just shutdown, but not yet closed locally */
375			sk->sk_state = SMC_APPFINCLOSEWAIT;
376		}
377		sock_put(sk); /* passive closing */
378		break;
379	case SMC_PEERFINCLOSEWAIT:
380		if (smc_cdc_rxed_any_close(conn)) {
381			sk->sk_state = SMC_CLOSED;
382			sock_put(sk); /* passive closing */
383		}
384		break;
385	case SMC_APPCLOSEWAIT1:
386	case SMC_APPCLOSEWAIT2:
387		/* postpone sock_put() for passive closing to cover
388		 * received SEND_SHUTDOWN as well
389		 */
390		break;
391	case SMC_APPFINCLOSEWAIT:
392	case SMC_PEERABORTWAIT:
393	case SMC_PROCESSABORT:
394	case SMC_CLOSED:
395		/* nothing to do, add tracing in future patch */
396		break;
397	}
398
399wakeup:
400	sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
401	sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
402
403	if (old_state != sk->sk_state) {
404		sk->sk_state_change(sk);
405		if ((sk->sk_state == SMC_CLOSED) &&
406		    (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket))
407			smc_conn_free(conn);
 
 
 
408	}
409	release_sock(sk);
 
 
410	sock_put(sk); /* sock_hold done by schedulers of close_work */
411}
412
413int smc_close_shutdown_write(struct smc_sock *smc)
414{
415	struct smc_connection *conn = &smc->conn;
416	struct sock *sk = &smc->sk;
417	int old_state;
418	long timeout;
419	int rc = 0;
420
421	timeout = current->flags & PF_EXITING ?
422		  0 : sock_flag(sk, SOCK_LINGER) ?
423		      sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
424
425	old_state = sk->sk_state;
426again:
427	switch (sk->sk_state) {
428	case SMC_ACTIVE:
429		smc_close_stream_wait(smc, timeout);
430		release_sock(sk);
431		cancel_delayed_work_sync(&conn->tx_work);
432		lock_sock(sk);
433		if (sk->sk_state != SMC_ACTIVE)
434			goto again;
435		/* send close wr request */
436		rc = smc_close_wr(conn);
437		if (rc)
438			break;
439		sk->sk_state = SMC_PEERCLOSEWAIT1;
440		break;
441	case SMC_APPCLOSEWAIT1:
442		/* passive close */
443		if (!smc_cdc_rxed_any_close(conn))
444			smc_close_stream_wait(smc, timeout);
445		release_sock(sk);
446		cancel_delayed_work_sync(&conn->tx_work);
447		lock_sock(sk);
448		if (sk->sk_state != SMC_APPCLOSEWAIT1)
449			goto again;
450		/* confirm close from peer */
451		rc = smc_close_wr(conn);
452		if (rc)
453			break;
454		sk->sk_state = SMC_APPCLOSEWAIT2;
455		break;
456	case SMC_APPCLOSEWAIT2:
457	case SMC_PEERFINCLOSEWAIT:
458	case SMC_PEERCLOSEWAIT1:
459	case SMC_PEERCLOSEWAIT2:
460	case SMC_APPFINCLOSEWAIT:
461	case SMC_PROCESSABORT:
462	case SMC_PEERABORTWAIT:
463		/* nothing to do, add tracing in future patch */
464		break;
465	}
466
467	if (old_state != sk->sk_state)
468		sk->sk_state_change(sk);
469	return rc;
470}
471
472/* Initialize close properties on connection establishment. */
473void smc_close_init(struct smc_sock *smc)
474{
475	INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
476}