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