1// SPDX-License-Identifier: GPL-2.0-or-later 2/* Client connection-specific management code. 3 * 4 * Copyright (C) 2016, 2020 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 * 7 * Client connections need to be cached for a little while after they've made a 8 * call so as to handle retransmitted DATA packets in case the server didn't 9 * receive the final ACK or terminating ABORT we sent it. 10 * 11 * There are flags of relevance to the cache: 12 * 13 * (2) DONT_REUSE - The connection should be discarded as soon as possible and 14 * should not be reused. This is set when an exclusive connection is used 15 * or a call ID counter overflows. 16 * 17 * The caching state may only be changed if the cache lock is held. 18 * 19 * There are two idle client connection expiry durations. If the total number 20 * of connections is below the reap threshold, we use the normal duration; if 21 * it's above, we use the fast duration. 22 */ 23 24#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 25 26#include <linux/slab.h> 27#include <linux/idr.h> 28#include <linux/timer.h> 29#include <linux/sched/signal.h> 30 31#include "ar-internal.h" 32 33__read_mostly unsigned int rxrpc_reap_client_connections = 900; 34__read_mostly unsigned long rxrpc_conn_idle_client_expiry = 2 * 60 * HZ; 35__read_mostly unsigned long rxrpc_conn_idle_client_fast_expiry = 2 * HZ; 36 37static void rxrpc_activate_bundle(struct rxrpc_bundle *bundle) 38{ 39 atomic_inc(&bundle->active); 40} 41 42/* 43 * Release a connection ID for a client connection. 44 */ 45static void rxrpc_put_client_connection_id(struct rxrpc_local *local, 46 struct rxrpc_connection *conn) 47{ 48 idr_remove(&local->conn_ids, conn->proto.cid >> RXRPC_CIDSHIFT); 49} 50 51/* 52 * Destroy the client connection ID tree. 53 */ 54static void rxrpc_destroy_client_conn_ids(struct rxrpc_local *local) 55{ 56 struct rxrpc_connection *conn; 57 int id; 58 59 if (!idr_is_empty(&local->conn_ids)) { 60 idr_for_each_entry(&local->conn_ids, conn, id) { 61 pr_err("AF_RXRPC: Leaked client conn %p {%d}\n", 62 conn, refcount_read(&conn->ref)); 63 } 64 BUG(); 65 } 66 67 idr_destroy(&local->conn_ids); 68} 69 70/* 71 * Allocate a connection bundle. 72 */ 73static struct rxrpc_bundle *rxrpc_alloc_bundle(struct rxrpc_call *call, 74 gfp_t gfp) 75{ 76 static atomic_t rxrpc_bundle_id; 77 struct rxrpc_bundle *bundle; 78 79 bundle = kzalloc(sizeof(*bundle), gfp); 80 if (bundle) { 81 bundle->local = call->local; 82 bundle->peer = rxrpc_get_peer(call->peer, rxrpc_peer_get_bundle); 83 bundle->key = key_get(call->key); 84 bundle->security = call->security; 85 bundle->exclusive = test_bit(RXRPC_CALL_EXCLUSIVE, &call->flags); 86 bundle->upgrade = test_bit(RXRPC_CALL_UPGRADE, &call->flags); 87 bundle->service_id = call->dest_srx.srx_service; 88 bundle->security_level = call->security_level; 89 bundle->debug_id = atomic_inc_return(&rxrpc_bundle_id); 90 refcount_set(&bundle->ref, 1); 91 atomic_set(&bundle->active, 1); 92 INIT_LIST_HEAD(&bundle->waiting_calls); 93 trace_rxrpc_bundle(bundle->debug_id, 1, rxrpc_bundle_new); 94 95 write_lock(&bundle->local->rxnet->conn_lock); 96 list_add_tail(&bundle->proc_link, &bundle->local->rxnet->bundle_proc_list); 97 write_unlock(&bundle->local->rxnet->conn_lock); 98 } 99 return bundle; 100} 101 102struct rxrpc_bundle *rxrpc_get_bundle(struct rxrpc_bundle *bundle, 103 enum rxrpc_bundle_trace why) 104{ 105 int r; 106 107 __refcount_inc(&bundle->ref, &r); 108 trace_rxrpc_bundle(bundle->debug_id, r + 1, why); 109 return bundle; 110} 111 112static void rxrpc_free_bundle(struct rxrpc_bundle *bundle) 113{ 114 trace_rxrpc_bundle(bundle->debug_id, refcount_read(&bundle->ref), 115 rxrpc_bundle_free); 116 write_lock(&bundle->local->rxnet->conn_lock); 117 list_del(&bundle->proc_link); 118 write_unlock(&bundle->local->rxnet->conn_lock); 119 rxrpc_put_peer(bundle->peer, rxrpc_peer_put_bundle); 120 key_put(bundle->key); 121 kfree(bundle); 122} 123 124void rxrpc_put_bundle(struct rxrpc_bundle *bundle, enum rxrpc_bundle_trace why) 125{ 126 unsigned int id; 127 bool dead; 128 int r; 129 130 if (bundle) { 131 id = bundle->debug_id; 132 dead = __refcount_dec_and_test(&bundle->ref, &r); 133 trace_rxrpc_bundle(id, r - 1, why); 134 if (dead) 135 rxrpc_free_bundle(bundle); 136 } 137} 138 139/* 140 * Get rid of outstanding client connection preallocations when a local 141 * endpoint is destroyed. 142 */ 143void rxrpc_purge_client_connections(struct rxrpc_local *local) 144{ 145 rxrpc_destroy_client_conn_ids(local); 146} 147 148/* 149 * Allocate a client connection. 150 */ 151static struct rxrpc_connection * 152rxrpc_alloc_client_connection(struct rxrpc_bundle *bundle) 153{ 154 struct rxrpc_connection *conn; 155 struct rxrpc_local *local = bundle->local; 156 struct rxrpc_net *rxnet = local->rxnet; 157 int id; 158 159 _enter(""); 160 161 conn = rxrpc_alloc_connection(rxnet, GFP_ATOMIC | __GFP_NOWARN); 162 if (!conn) 163 return ERR_PTR(-ENOMEM); 164 165 id = idr_alloc_cyclic(&local->conn_ids, conn, 1, 0x40000000, 166 GFP_ATOMIC | __GFP_NOWARN); 167 if (id < 0) { 168 kfree(conn); 169 return ERR_PTR(id); 170 } 171 172 refcount_set(&conn->ref, 1); 173 conn->proto.cid = id << RXRPC_CIDSHIFT; 174 conn->proto.epoch = local->rxnet->epoch; 175 conn->out_clientflag = RXRPC_CLIENT_INITIATED; 176 conn->bundle = rxrpc_get_bundle(bundle, rxrpc_bundle_get_client_conn); 177 conn->local = rxrpc_get_local(bundle->local, rxrpc_local_get_client_conn); 178 conn->peer = rxrpc_get_peer(bundle->peer, rxrpc_peer_get_client_conn); 179 conn->key = key_get(bundle->key); 180 conn->security = bundle->security; 181 conn->exclusive = bundle->exclusive; 182 conn->upgrade = bundle->upgrade; 183 conn->orig_service_id = bundle->service_id; 184 conn->security_level = bundle->security_level; 185 conn->state = RXRPC_CONN_CLIENT_UNSECURED; 186 conn->service_id = conn->orig_service_id; 187 188 if (conn->security == &rxrpc_no_security) 189 conn->state = RXRPC_CONN_CLIENT; 190 191 atomic_inc(&rxnet->nr_conns); 192 write_lock(&rxnet->conn_lock); 193 list_add_tail(&conn->proc_link, &rxnet->conn_proc_list); 194 write_unlock(&rxnet->conn_lock); 195 196 rxrpc_see_connection(conn, rxrpc_conn_new_client); 197 198 atomic_inc(&rxnet->nr_client_conns); 199 trace_rxrpc_client(conn, -1, rxrpc_client_alloc); 200 return conn; 201} 202 203/* 204 * Determine if a connection may be reused. 205 */ 206static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn) 207{ 208 struct rxrpc_net *rxnet; 209 int id_cursor, id, distance, limit; 210 211 if (!conn) 212 goto dont_reuse; 213 214 rxnet = conn->rxnet; 215 if (test_bit(RXRPC_CONN_DONT_REUSE, &conn->flags)) 216 goto dont_reuse; 217 218 if ((conn->state != RXRPC_CONN_CLIENT_UNSECURED && 219 conn->state != RXRPC_CONN_CLIENT) || 220 conn->proto.epoch != rxnet->epoch) 221 goto mark_dont_reuse; 222 223 /* The IDR tree gets very expensive on memory if the connection IDs are 224 * widely scattered throughout the number space, so we shall want to 225 * kill off connections that, say, have an ID more than about four 226 * times the maximum number of client conns away from the current 227 * allocation point to try and keep the IDs concentrated. 228 */ 229 id_cursor = idr_get_cursor(&conn->local->conn_ids); 230 id = conn->proto.cid >> RXRPC_CIDSHIFT; 231 distance = id - id_cursor; 232 if (distance < 0) 233 distance = -distance; 234 limit = max_t(unsigned long, atomic_read(&rxnet->nr_conns) * 4, 1024); 235 if (distance > limit) 236 goto mark_dont_reuse; 237 238 return true; 239 240mark_dont_reuse: 241 set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags); 242dont_reuse: 243 return false; 244} 245 246/* 247 * Look up the conn bundle that matches the connection parameters, adding it if 248 * it doesn't yet exist. 249 */ 250int rxrpc_look_up_bundle(struct rxrpc_call *call, gfp_t gfp) 251{ 252 struct rxrpc_bundle *bundle, *candidate; 253 struct rxrpc_local *local = call->local; 254 struct rb_node *p, **pp, *parent; 255 long diff; 256 bool upgrade = test_bit(RXRPC_CALL_UPGRADE, &call->flags); 257 258 _enter("{%px,%x,%u,%u}", 259 call->peer, key_serial(call->key), call->security_level, 260 upgrade); 261 262 if (test_bit(RXRPC_CALL_EXCLUSIVE, &call->flags)) { 263 call->bundle = rxrpc_alloc_bundle(call, gfp); 264 return call->bundle ? 0 : -ENOMEM; 265 } 266 267 /* First, see if the bundle is already there. */ 268 _debug("search 1"); 269 spin_lock(&local->client_bundles_lock); 270 p = local->client_bundles.rb_node; 271 while (p) { 272 bundle = rb_entry(p, struct rxrpc_bundle, local_node); 273 274#define cmp(X, Y) ((long)(X) - (long)(Y)) 275 diff = (cmp(bundle->peer, call->peer) ?: 276 cmp(bundle->key, call->key) ?: 277 cmp(bundle->security_level, call->security_level) ?: 278 cmp(bundle->upgrade, upgrade)); 279#undef cmp 280 if (diff < 0) 281 p = p->rb_left; 282 else if (diff > 0) 283 p = p->rb_right; 284 else 285 goto found_bundle; 286 } 287 spin_unlock(&local->client_bundles_lock); 288 _debug("not found"); 289 290 /* It wasn't. We need to add one. */ 291 candidate = rxrpc_alloc_bundle(call, gfp); 292 if (!candidate) 293 return -ENOMEM; 294 295 _debug("search 2"); 296 spin_lock(&local->client_bundles_lock); 297 pp = &local->client_bundles.rb_node; 298 parent = NULL; 299 while (*pp) { 300 parent = *pp; 301 bundle = rb_entry(parent, struct rxrpc_bundle, local_node); 302 303#define cmp(X, Y) ((long)(X) - (long)(Y)) 304 diff = (cmp(bundle->peer, call->peer) ?: 305 cmp(bundle->key, call->key) ?: 306 cmp(bundle->security_level, call->security_level) ?: 307 cmp(bundle->upgrade, upgrade)); 308#undef cmp 309 if (diff < 0) 310 pp = &(*pp)->rb_left; 311 else if (diff > 0) 312 pp = &(*pp)->rb_right; 313 else 314 goto found_bundle_free; 315 } 316 317 _debug("new bundle"); 318 rb_link_node(&candidate->local_node, parent, pp); 319 rb_insert_color(&candidate->local_node, &local->client_bundles); 320 call->bundle = rxrpc_get_bundle(candidate, rxrpc_bundle_get_client_call); 321 spin_unlock(&local->client_bundles_lock); 322 _leave(" = B=%u [new]", call->bundle->debug_id); 323 return 0; 324 325found_bundle_free: 326 rxrpc_free_bundle(candidate); 327found_bundle: 328 call->bundle = rxrpc_get_bundle(bundle, rxrpc_bundle_get_client_call); 329 rxrpc_activate_bundle(bundle); 330 spin_unlock(&local->client_bundles_lock); 331 _leave(" = B=%u [found]", call->bundle->debug_id); 332 return 0; 333} 334 335/* 336 * Allocate a new connection and add it into a bundle. 337 */ 338static bool rxrpc_add_conn_to_bundle(struct rxrpc_bundle *bundle, 339 unsigned int slot) 340{ 341 struct rxrpc_connection *conn, *old; 342 unsigned int shift = slot * RXRPC_MAXCALLS; 343 unsigned int i; 344 345 old = bundle->conns[slot]; 346 if (old) { 347 bundle->conns[slot] = NULL; 348 bundle->conn_ids[slot] = 0; 349 trace_rxrpc_client(old, -1, rxrpc_client_replace); 350 rxrpc_put_connection(old, rxrpc_conn_put_noreuse); 351 } 352 353 conn = rxrpc_alloc_client_connection(bundle); 354 if (IS_ERR(conn)) { 355 bundle->alloc_error = PTR_ERR(conn); 356 return false; 357 } 358 359 rxrpc_activate_bundle(bundle); 360 conn->bundle_shift = shift; 361 bundle->conns[slot] = conn; 362 bundle->conn_ids[slot] = conn->debug_id; 363 for (i = 0; i < RXRPC_MAXCALLS; i++) 364 set_bit(shift + i, &bundle->avail_chans); 365 return true; 366} 367 368/* 369 * Add a connection to a bundle if there are no usable connections or we have 370 * connections waiting for extra capacity. 371 */ 372static bool rxrpc_bundle_has_space(struct rxrpc_bundle *bundle) 373{ 374 int slot = -1, i, usable; 375 376 _enter(""); 377 378 bundle->alloc_error = 0; 379 380 /* See if there are any usable connections. */ 381 usable = 0; 382 for (i = 0; i < ARRAY_SIZE(bundle->conns); i++) { 383 if (rxrpc_may_reuse_conn(bundle->conns[i])) 384 usable++; 385 else if (slot == -1) 386 slot = i; 387 } 388 389 if (!usable && bundle->upgrade) 390 bundle->try_upgrade = true; 391 392 if (!usable) 393 goto alloc_conn; 394 395 if (!bundle->avail_chans && 396 !bundle->try_upgrade && 397 usable < ARRAY_SIZE(bundle->conns)) 398 goto alloc_conn; 399 400 _leave(""); 401 return usable; 402 403alloc_conn: 404 return slot >= 0 ? rxrpc_add_conn_to_bundle(bundle, slot) : false; 405} 406 407/* 408 * Assign a channel to the call at the front of the queue and wake the call up. 409 * We don't increment the callNumber counter until this number has been exposed 410 * to the world. 411 */ 412static void rxrpc_activate_one_channel(struct rxrpc_connection *conn, 413 unsigned int channel) 414{ 415 struct rxrpc_channel *chan = &conn->channels[channel]; 416 struct rxrpc_bundle *bundle = conn->bundle; 417 struct rxrpc_call *call = list_entry(bundle->waiting_calls.next, 418 struct rxrpc_call, wait_link); 419 u32 call_id = chan->call_counter + 1; 420 421 _enter("C=%x,%u", conn->debug_id, channel); 422 423 list_del_init(&call->wait_link); 424 425 trace_rxrpc_client(conn, channel, rxrpc_client_chan_activate); 426 427 /* Cancel the final ACK on the previous call if it hasn't been sent yet 428 * as the DATA packet will implicitly ACK it. 429 */ 430 clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags); 431 clear_bit(conn->bundle_shift + channel, &bundle->avail_chans); 432 433 rxrpc_see_call(call, rxrpc_call_see_activate_client); 434 call->conn = rxrpc_get_connection(conn, rxrpc_conn_get_activate_call); 435 call->cid = conn->proto.cid | channel; 436 call->call_id = call_id; 437 call->dest_srx.srx_service = conn->service_id; 438 call->cong_ssthresh = call->peer->cong_ssthresh; 439 if (call->cong_cwnd >= call->cong_ssthresh) 440 call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; 441 else 442 call->cong_mode = RXRPC_CALL_SLOW_START; 443 444 chan->call_id = call_id; 445 chan->call_debug_id = call->debug_id; 446 chan->call = call; 447 448 rxrpc_see_call(call, rxrpc_call_see_connected); 449 trace_rxrpc_connect_call(call); 450 call->tx_last_sent = ktime_get_real(); 451 rxrpc_start_call_timer(call); 452 rxrpc_set_call_state(call, RXRPC_CALL_CLIENT_SEND_REQUEST); 453 wake_up(&call->waitq); 454} 455 456/* 457 * Remove a connection from the idle list if it's on it. 458 */ 459static void rxrpc_unidle_conn(struct rxrpc_connection *conn) 460{ 461 if (!list_empty(&conn->cache_link)) { 462 list_del_init(&conn->cache_link); 463 rxrpc_put_connection(conn, rxrpc_conn_put_unidle); 464 } 465} 466 467/* 468 * Assign channels and callNumbers to waiting calls. 469 */ 470static void rxrpc_activate_channels(struct rxrpc_bundle *bundle) 471{ 472 struct rxrpc_connection *conn; 473 unsigned long avail, mask; 474 unsigned int channel, slot; 475 476 trace_rxrpc_client(NULL, -1, rxrpc_client_activate_chans); 477 478 if (bundle->try_upgrade) 479 mask = 1; 480 else 481 mask = ULONG_MAX; 482 483 while (!list_empty(&bundle->waiting_calls)) { 484 avail = bundle->avail_chans & mask; 485 if (!avail) 486 break; 487 channel = __ffs(avail); 488 clear_bit(channel, &bundle->avail_chans); 489 490 slot = channel / RXRPC_MAXCALLS; 491 conn = bundle->conns[slot]; 492 if (!conn) 493 break; 494 495 if (bundle->try_upgrade) 496 set_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags); 497 rxrpc_unidle_conn(conn); 498 499 channel &= (RXRPC_MAXCALLS - 1); 500 conn->act_chans |= 1 << channel; 501 rxrpc_activate_one_channel(conn, channel); 502 } 503} 504 505/* 506 * Connect waiting channels (called from the I/O thread). 507 */ 508void rxrpc_connect_client_calls(struct rxrpc_local *local) 509{ 510 struct rxrpc_call *call; 511 512 while ((call = list_first_entry_or_null(&local->new_client_calls, 513 struct rxrpc_call, wait_link)) 514 ) { 515 struct rxrpc_bundle *bundle = call->bundle; 516 517 spin_lock(&local->client_call_lock); 518 list_move_tail(&call->wait_link, &bundle->waiting_calls); 519 spin_unlock(&local->client_call_lock); 520 521 if (rxrpc_bundle_has_space(bundle)) 522 rxrpc_activate_channels(bundle); 523 } 524} 525 526/* 527 * Note that a call, and thus a connection, is about to be exposed to the 528 * world. 529 */ 530void rxrpc_expose_client_call(struct rxrpc_call *call) 531{ 532 unsigned int channel = call->cid & RXRPC_CHANNELMASK; 533 struct rxrpc_connection *conn = call->conn; 534 struct rxrpc_channel *chan = &conn->channels[channel]; 535 536 if (!test_and_set_bit(RXRPC_CALL_EXPOSED, &call->flags)) { 537 /* Mark the call ID as being used. If the callNumber counter 538 * exceeds ~2 billion, we kill the connection after its 539 * outstanding calls have finished so that the counter doesn't 540 * wrap. 541 */ 542 chan->call_counter++; 543 if (chan->call_counter >= INT_MAX) 544 set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags); 545 trace_rxrpc_client(conn, channel, rxrpc_client_exposed); 546 547 spin_lock(&call->peer->lock); 548 hlist_add_head(&call->error_link, &call->peer->error_targets); 549 spin_unlock(&call->peer->lock); 550 } 551} 552 553/* 554 * Set the reap timer. 555 */ 556static void rxrpc_set_client_reap_timer(struct rxrpc_local *local) 557{ 558 if (!local->kill_all_client_conns) { 559 unsigned long now = jiffies; 560 unsigned long reap_at = now + rxrpc_conn_idle_client_expiry; 561 562 if (local->rxnet->live) 563 timer_reduce(&local->client_conn_reap_timer, reap_at); 564 } 565} 566 567/* 568 * Disconnect a client call. 569 */ 570void rxrpc_disconnect_client_call(struct rxrpc_bundle *bundle, struct rxrpc_call *call) 571{ 572 struct rxrpc_connection *conn; 573 struct rxrpc_channel *chan = NULL; 574 struct rxrpc_local *local = bundle->local; 575 unsigned int channel; 576 bool may_reuse; 577 u32 cid; 578 579 _enter("c=%x", call->debug_id); 580 581 /* Calls that have never actually been assigned a channel can simply be 582 * discarded. 583 */ 584 conn = call->conn; 585 if (!conn) { 586 _debug("call is waiting"); 587 ASSERTCMP(call->call_id, ==, 0); 588 ASSERT(!test_bit(RXRPC_CALL_EXPOSED, &call->flags)); 589 list_del_init(&call->wait_link); 590 return; 591 } 592 593 cid = call->cid; 594 channel = cid & RXRPC_CHANNELMASK; 595 chan = &conn->channels[channel]; 596 trace_rxrpc_client(conn, channel, rxrpc_client_chan_disconnect); 597 598 if (WARN_ON(chan->call != call)) 599 return; 600 601 may_reuse = rxrpc_may_reuse_conn(conn); 602 603 /* If a client call was exposed to the world, we save the result for 604 * retransmission. 605 * 606 * We use a barrier here so that the call number and abort code can be 607 * read without needing to take a lock. 608 * 609 * TODO: Make the incoming packet handler check this and handle 610 * terminal retransmission without requiring access to the call. 611 */ 612 if (test_bit(RXRPC_CALL_EXPOSED, &call->flags)) { 613 _debug("exposed %u,%u", call->call_id, call->abort_code); 614 __rxrpc_disconnect_call(conn, call); 615 616 if (test_and_clear_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) { 617 trace_rxrpc_client(conn, channel, rxrpc_client_to_active); 618 bundle->try_upgrade = false; 619 if (may_reuse) 620 rxrpc_activate_channels(bundle); 621 } 622 } 623 624 /* See if we can pass the channel directly to another call. */ 625 if (may_reuse && !list_empty(&bundle->waiting_calls)) { 626 trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass); 627 rxrpc_activate_one_channel(conn, channel); 628 return; 629 } 630 631 /* Schedule the final ACK to be transmitted in a short while so that it 632 * can be skipped if we find a follow-on call. The first DATA packet 633 * of the follow on call will implicitly ACK this call. 634 */ 635 if (call->completion == RXRPC_CALL_SUCCEEDED && 636 test_bit(RXRPC_CALL_EXPOSED, &call->flags)) { 637 unsigned long final_ack_at = jiffies + 2; 638 639 chan->final_ack_at = final_ack_at; 640 smp_wmb(); /* vs rxrpc_process_delayed_final_acks() */ 641 set_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags); 642 rxrpc_reduce_conn_timer(conn, final_ack_at); 643 } 644 645 /* Deactivate the channel. */ 646 chan->call = NULL; 647 set_bit(conn->bundle_shift + channel, &conn->bundle->avail_chans); 648 conn->act_chans &= ~(1 << channel); 649 650 /* If no channels remain active, then put the connection on the idle 651 * list for a short while. Give it a ref to stop it going away if it 652 * becomes unbundled. 653 */ 654 if (!conn->act_chans) { 655 trace_rxrpc_client(conn, channel, rxrpc_client_to_idle); 656 conn->idle_timestamp = jiffies; 657 658 rxrpc_get_connection(conn, rxrpc_conn_get_idle); 659 list_move_tail(&conn->cache_link, &local->idle_client_conns); 660 661 rxrpc_set_client_reap_timer(local); 662 } 663} 664 665/* 666 * Remove a connection from a bundle. 667 */ 668static void rxrpc_unbundle_conn(struct rxrpc_connection *conn) 669{ 670 struct rxrpc_bundle *bundle = conn->bundle; 671 unsigned int bindex; 672 int i; 673 674 _enter("C=%x", conn->debug_id); 675 676 if (conn->flags & RXRPC_CONN_FINAL_ACK_MASK) 677 rxrpc_process_delayed_final_acks(conn, true); 678 679 bindex = conn->bundle_shift / RXRPC_MAXCALLS; 680 if (bundle->conns[bindex] == conn) { 681 _debug("clear slot %u", bindex); 682 bundle->conns[bindex] = NULL; 683 bundle->conn_ids[bindex] = 0; 684 for (i = 0; i < RXRPC_MAXCALLS; i++) 685 clear_bit(conn->bundle_shift + i, &bundle->avail_chans); 686 rxrpc_put_client_connection_id(bundle->local, conn); 687 rxrpc_deactivate_bundle(bundle); 688 rxrpc_put_connection(conn, rxrpc_conn_put_unbundle); 689 } 690} 691 692/* 693 * Drop the active count on a bundle. 694 */ 695void rxrpc_deactivate_bundle(struct rxrpc_bundle *bundle) 696{ 697 struct rxrpc_local *local; 698 bool need_put = false; 699 700 if (!bundle) 701 return; 702 703 local = bundle->local; 704 if (atomic_dec_and_lock(&bundle->active, &local->client_bundles_lock)) { 705 if (!bundle->exclusive) { 706 _debug("erase bundle"); 707 rb_erase(&bundle->local_node, &local->client_bundles); 708 need_put = true; 709 } 710 711 spin_unlock(&local->client_bundles_lock); 712 if (need_put) 713 rxrpc_put_bundle(bundle, rxrpc_bundle_put_discard); 714 } 715} 716 717/* 718 * Clean up a dead client connection. 719 */ 720void rxrpc_kill_client_conn(struct rxrpc_connection *conn) 721{ 722 struct rxrpc_local *local = conn->local; 723 struct rxrpc_net *rxnet = local->rxnet; 724 725 _enter("C=%x", conn->debug_id); 726 727 trace_rxrpc_client(conn, -1, rxrpc_client_cleanup); 728 atomic_dec(&rxnet->nr_client_conns); 729 730 rxrpc_put_client_connection_id(local, conn); 731} 732 733/* 734 * Discard expired client connections from the idle list. Each conn in the 735 * idle list has been exposed and holds an extra ref because of that. 736 * 737 * This may be called from conn setup or from a work item so cannot be 738 * considered non-reentrant. 739 */ 740void rxrpc_discard_expired_client_conns(struct rxrpc_local *local) 741{ 742 struct rxrpc_connection *conn; 743 unsigned long expiry, conn_expires_at, now; 744 unsigned int nr_conns; 745 746 _enter(""); 747 748 /* We keep an estimate of what the number of conns ought to be after 749 * we've discarded some so that we don't overdo the discarding. 750 */ 751 nr_conns = atomic_read(&local->rxnet->nr_client_conns); 752 753next: 754 conn = list_first_entry_or_null(&local->idle_client_conns, 755 struct rxrpc_connection, cache_link); 756 if (!conn) 757 return; 758 759 if (!local->kill_all_client_conns) { 760 /* If the number of connections is over the reap limit, we 761 * expedite discard by reducing the expiry timeout. We must, 762 * however, have at least a short grace period to be able to do 763 * final-ACK or ABORT retransmission. 764 */ 765 expiry = rxrpc_conn_idle_client_expiry; 766 if (nr_conns > rxrpc_reap_client_connections) 767 expiry = rxrpc_conn_idle_client_fast_expiry; 768 if (conn->local->service_closed) 769 expiry = rxrpc_closed_conn_expiry * HZ; 770 771 conn_expires_at = conn->idle_timestamp + expiry; 772 773 now = jiffies; 774 if (time_after(conn_expires_at, now)) 775 goto not_yet_expired; 776 } 777 778 atomic_dec(&conn->active); 779 trace_rxrpc_client(conn, -1, rxrpc_client_discard); 780 list_del_init(&conn->cache_link); 781 782 rxrpc_unbundle_conn(conn); 783 /* Drop the ->cache_link ref */ 784 rxrpc_put_connection(conn, rxrpc_conn_put_discard_idle); 785 786 nr_conns--; 787 goto next; 788 789not_yet_expired: 790 /* The connection at the front of the queue hasn't yet expired, so 791 * schedule the work item for that point if we discarded something. 792 * 793 * We don't worry if the work item is already scheduled - it can look 794 * after rescheduling itself at a later time. We could cancel it, but 795 * then things get messier. 796 */ 797 _debug("not yet"); 798 if (!local->kill_all_client_conns) 799 timer_reduce(&local->client_conn_reap_timer, conn_expires_at); 800 801 _leave(""); 802} 803 804/* 805 * Clean up the client connections on a local endpoint. 806 */ 807void rxrpc_clean_up_local_conns(struct rxrpc_local *local) 808{ 809 struct rxrpc_connection *conn; 810 811 _enter(""); 812 813 local->kill_all_client_conns = true; 814 815 del_timer_sync(&local->client_conn_reap_timer); 816 817 while ((conn = list_first_entry_or_null(&local->idle_client_conns, 818 struct rxrpc_connection, cache_link))) { 819 list_del_init(&conn->cache_link); 820 atomic_dec(&conn->active); 821 trace_rxrpc_client(conn, -1, rxrpc_client_discard); 822 rxrpc_unbundle_conn(conn); 823 rxrpc_put_connection(conn, rxrpc_conn_put_local_dead); 824 } 825 826 _leave(" [culled]"); 827} 828