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 /* 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
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
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
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
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
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 */
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
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
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
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 */
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
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. */
503 void smc_close_init(struct smc_sock *smc)
504 {
505 INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
506 }
507
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