tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 smc->clcsock->sk->sk_data_ready = smc->clcsk_data_ready;
218 smc->clcsock->sk->sk_user_data = NULL;
219 rc = kernel_sock_shutdown(smc->clcsock, SHUT_RDWR);
220 }
221 smc_close_cleanup_listen(sk);
222 release_sock(sk);
223 flush_work(&smc->tcp_listen_work);
224 lock_sock(sk);
225 break;
226 case SMC_ACTIVE:
227 smc_close_stream_wait(smc, timeout);
228 release_sock(sk);
229 cancel_delayed_work_sync(&conn->tx_work);
230 lock_sock(sk);
231 if (sk->sk_state == SMC_ACTIVE) {
232 /* send close request */
233 rc = smc_close_final(conn);
234 sk->sk_state = SMC_PEERCLOSEWAIT1;
235
236 /* actively shutdown clcsock before peer close it,
237 * prevent peer from entering TIME_WAIT state.
238 */
239 if (smc->clcsock && smc->clcsock->sk) {
240 rc1 = kernel_sock_shutdown(smc->clcsock,
241 SHUT_RDWR);
242 rc = rc ? rc : rc1;
243 }
244 } else {
245 /* peer event has changed the state */
246 goto again;
247 }
248 break;
249 case SMC_APPFINCLOSEWAIT:
250 /* socket already shutdown wr or both (active close) */
251 if (txflags->peer_done_writing &&
252 !smc_close_sent_any_close(conn)) {
253 /* just shutdown wr done, send close request */
254 rc = smc_close_final(conn);
255 }
256 sk->sk_state = SMC_CLOSED;
257 break;
258 case SMC_APPCLOSEWAIT1:
259 case SMC_APPCLOSEWAIT2:
260 if (!smc_cdc_rxed_any_close(conn))
261 smc_close_stream_wait(smc, timeout);
262 release_sock(sk);
263 cancel_delayed_work_sync(&conn->tx_work);
264 lock_sock(sk);
265 if (sk->sk_state != SMC_APPCLOSEWAIT1 &&
266 sk->sk_state != SMC_APPCLOSEWAIT2)
267 goto again;
268 /* confirm close from peer */
269 rc = smc_close_final(conn);
270 if (smc_cdc_rxed_any_close(conn)) {
271 /* peer has closed the socket already */
272 sk->sk_state = SMC_CLOSED;
273 sock_put(sk); /* postponed passive closing */
274 } else {
275 /* peer has just issued a shutdown write */
276 sk->sk_state = SMC_PEERFINCLOSEWAIT;
277 }
278 break;
279 case SMC_PEERCLOSEWAIT1:
280 case SMC_PEERCLOSEWAIT2:
281 if (txflags->peer_done_writing &&
282 !smc_close_sent_any_close(conn)) {
283 /* just shutdown wr done, send close request */
284 rc = smc_close_final(conn);
285 }
286 /* peer sending PeerConnectionClosed will cause transition */
287 break;
288 case SMC_PEERFINCLOSEWAIT:
289 /* peer sending PeerConnectionClosed will cause transition */
290 break;
291 case SMC_PROCESSABORT:
292 rc = smc_close_abort(conn);
293 sk->sk_state = SMC_CLOSED;
294 break;
295 case SMC_PEERABORTWAIT:
296 sk->sk_state = SMC_CLOSED;
297 break;
298 case SMC_CLOSED:
299 /* nothing to do, add tracing in future patch */
300 break;
301 }
302
303 if (old_state != sk->sk_state)
304 sk->sk_state_change(sk);
305 return rc;
306}
307
308static void smc_close_passive_abort_received(struct smc_sock *smc)
309{
310 struct smc_cdc_conn_state_flags *txflags =
311 &smc->conn.local_tx_ctrl.conn_state_flags;
312 struct sock *sk = &smc->sk;
313
314 switch (sk->sk_state) {
315 case SMC_INIT:
316 case SMC_ACTIVE:
317 case SMC_APPCLOSEWAIT1:
318 sk->sk_state = SMC_PROCESSABORT;
319 sock_put(sk); /* passive closing */
320 break;
321 case SMC_APPFINCLOSEWAIT:
322 sk->sk_state = SMC_PROCESSABORT;
323 break;
324 case SMC_PEERCLOSEWAIT1:
325 case SMC_PEERCLOSEWAIT2:
326 if (txflags->peer_done_writing &&
327 !smc_close_sent_any_close(&smc->conn))
328 /* just shutdown, but not yet closed locally */
329 sk->sk_state = SMC_PROCESSABORT;
330 else
331 sk->sk_state = SMC_CLOSED;
332 sock_put(sk); /* passive closing */
333 break;
334 case SMC_APPCLOSEWAIT2:
335 case SMC_PEERFINCLOSEWAIT:
336 sk->sk_state = SMC_CLOSED;
337 sock_put(sk); /* passive closing */
338 break;
339 case SMC_PEERABORTWAIT:
340 sk->sk_state = SMC_CLOSED;
341 break;
342 case SMC_PROCESSABORT:
343 /* nothing to do, add tracing in future patch */
344 break;
345 }
346}
347
348/* Either some kind of closing has been received: peer_conn_closed,
349 * peer_conn_abort, or peer_done_writing
350 * or the link group of the connection terminates abnormally.
351 */
352static void smc_close_passive_work(struct work_struct *work)
353{
354 struct smc_connection *conn = container_of(work,
355 struct smc_connection,
356 close_work);
357 struct smc_sock *smc = container_of(conn, struct smc_sock, conn);
358 struct smc_cdc_conn_state_flags *rxflags;
359 bool release_clcsock = false;
360 struct sock *sk = &smc->sk;
361 int old_state;
362
363 lock_sock(sk);
364 old_state = sk->sk_state;
365
366 rxflags = &conn->local_rx_ctrl.conn_state_flags;
367 if (rxflags->peer_conn_abort) {
368 /* peer has not received all data */
369 smc_close_passive_abort_received(smc);
370 release_sock(sk);
371 cancel_delayed_work_sync(&conn->tx_work);
372 lock_sock(sk);
373 goto wakeup;
374 }
375
376 switch (sk->sk_state) {
377 case SMC_INIT:
378 sk->sk_state = SMC_APPCLOSEWAIT1;
379 break;
380 case SMC_ACTIVE:
381 sk->sk_state = SMC_APPCLOSEWAIT1;
382 /* postpone sock_put() for passive closing to cover
383 * received SEND_SHUTDOWN as well
384 */
385 break;
386 case SMC_PEERCLOSEWAIT1:
387 if (rxflags->peer_done_writing)
388 sk->sk_state = SMC_PEERCLOSEWAIT2;
389 fallthrough;
390 /* to check for closing */
391 case SMC_PEERCLOSEWAIT2:
392 if (!smc_cdc_rxed_any_close(conn))
393 break;
394 if (sock_flag(sk, SOCK_DEAD) &&
395 smc_close_sent_any_close(conn)) {
396 /* smc_release has already been called locally */
397 sk->sk_state = SMC_CLOSED;
398 } else {
399 /* just shutdown, but not yet closed locally */
400 sk->sk_state = SMC_APPFINCLOSEWAIT;
401 }
402 sock_put(sk); /* passive closing */
403 break;
404 case SMC_PEERFINCLOSEWAIT:
405 if (smc_cdc_rxed_any_close(conn)) {
406 sk->sk_state = SMC_CLOSED;
407 sock_put(sk); /* passive closing */
408 }
409 break;
410 case SMC_APPCLOSEWAIT1:
411 case SMC_APPCLOSEWAIT2:
412 /* postpone sock_put() for passive closing to cover
413 * received SEND_SHUTDOWN as well
414 */
415 break;
416 case SMC_APPFINCLOSEWAIT:
417 case SMC_PEERABORTWAIT:
418 case SMC_PROCESSABORT:
419 case SMC_CLOSED:
420 /* nothing to do, add tracing in future patch */
421 break;
422 }
423
424wakeup:
425 sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
426 sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
427
428 if (old_state != sk->sk_state) {
429 sk->sk_state_change(sk);
430 if ((sk->sk_state == SMC_CLOSED) &&
431 (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
432 smc_conn_free(conn);
433 if (smc->clcsock)
434 release_clcsock = true;
435 }
436 }
437 release_sock(sk);
438 if (release_clcsock)
439 smc_clcsock_release(smc);
440 sock_put(sk); /* sock_hold done by schedulers of close_work */
441}
442
443int smc_close_shutdown_write(struct smc_sock *smc)
444{
445 struct smc_connection *conn = &smc->conn;
446 struct sock *sk = &smc->sk;
447 int old_state;
448 long timeout;
449 int rc = 0;
450
451 timeout = current->flags & PF_EXITING ?
452 0 : sock_flag(sk, SOCK_LINGER) ?
453 sk->sk_lingertime : SMC_MAX_STREAM_WAIT_TIMEOUT;
454
455 old_state = sk->sk_state;
456again:
457 switch (sk->sk_state) {
458 case SMC_ACTIVE:
459 smc_close_stream_wait(smc, timeout);
460 release_sock(sk);
461 cancel_delayed_work_sync(&conn->tx_work);
462 lock_sock(sk);
463 if (sk->sk_state != SMC_ACTIVE)
464 goto again;
465 /* send close wr request */
466 rc = smc_close_wr(conn);
467 sk->sk_state = SMC_PEERCLOSEWAIT1;
468 break;
469 case SMC_APPCLOSEWAIT1:
470 /* passive close */
471 if (!smc_cdc_rxed_any_close(conn))
472 smc_close_stream_wait(smc, timeout);
473 release_sock(sk);
474 cancel_delayed_work_sync(&conn->tx_work);
475 lock_sock(sk);
476 if (sk->sk_state != SMC_APPCLOSEWAIT1)
477 goto again;
478 /* confirm close from peer */
479 rc = smc_close_wr(conn);
480 sk->sk_state = SMC_APPCLOSEWAIT2;
481 break;
482 case SMC_APPCLOSEWAIT2:
483 case SMC_PEERFINCLOSEWAIT:
484 case SMC_PEERCLOSEWAIT1:
485 case SMC_PEERCLOSEWAIT2:
486 case SMC_APPFINCLOSEWAIT:
487 case SMC_PROCESSABORT:
488 case SMC_PEERABORTWAIT:
489 /* nothing to do, add tracing in future patch */
490 break;
491 }
492
493 if (old_state != sk->sk_state)
494 sk->sk_state_change(sk);
495 return rc;
496}
497
498/* Initialize close properties on connection establishment. */
499void smc_close_init(struct smc_sock *smc)
500{
501 INIT_WORK(&smc->conn.close_work, smc_close_passive_work);
502}