xref: /linux/net/smc/smc_close.c (revision 0ea5c948cb64bab5bc7a5516774eb8536f05aa0d)
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 */
smc_clcsock_release(struct smc_sock * smc)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 
smc_close_cleanup_listen(struct sock * parent)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 */
smc_close_stream_wait(struct smc_sock * smc,long timeout)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 	/* 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 
smc_close_wake_tx_prepared(struct smc_sock * smc)81 void 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 
smc_close_wr(struct smc_connection * conn)88 static 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 
smc_close_final(struct smc_connection * conn)95 static 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 
smc_close_abort(struct smc_connection * conn)107 int 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 
smc_close_cancel_work(struct smc_sock * smc)114 static 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  */
smc_close_active_abort(struct smc_sock * smc)128 void 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 
smc_close_sent_any_close(struct smc_connection * conn)187 static 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 
smc_close_active(struct smc_sock * smc)193 int 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;
209 again:
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 
smc_close_passive_abort_received(struct smc_sock * smc)312 static 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  */
smc_close_passive_work(struct work_struct * work)356 static 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 
428 wakeup:
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 
smc_close_shutdown_write(struct smc_sock * smc)447 int 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;
460 again:
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. */
smc_close_init(struct smc_sock * smc)503 void smc_close_init(struct smc_sock *smc)
504 {
505 	INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
506 }
507