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b4d0d230 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
4a3388c8 DH |
2 | /* Client connection-specific management code. |
3 | * | |
4 | * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. | |
5 | * Written by David Howells (dhowells@redhat.com) | |
6 | * | |
45025bce DH |
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 | * Client connections can be in one of a number of cache states: | |
12 | * | |
13 | * (1) INACTIVE - The connection is not held in any list and may not have been | |
14 | * exposed to the world. If it has been previously exposed, it was | |
15 | * discarded from the idle list after expiring. | |
16 | * | |
17 | * (2) WAITING - The connection is waiting for the number of client conns to | |
18 | * drop below the maximum capacity. Calls may be in progress upon it from | |
19 | * when it was active and got culled. | |
20 | * | |
21 | * The connection is on the rxrpc_waiting_client_conns list which is kept | |
22 | * in to-be-granted order. Culled conns with waiters go to the back of | |
23 | * the queue just like new conns. | |
24 | * | |
25 | * (3) ACTIVE - The connection has at least one call in progress upon it, it | |
26 | * may freely grant available channels to new calls and calls may be | |
27 | * waiting on it for channels to become available. | |
28 | * | |
2baec2c3 | 29 | * The connection is on the rxnet->active_client_conns list which is kept |
45025bce DH |
30 | * in activation order for culling purposes. |
31 | * | |
32 | * rxrpc_nr_active_client_conns is held incremented also. | |
33 | * | |
4e255721 DH |
34 | * (4) UPGRADE - As for ACTIVE, but only one call may be in progress and is |
35 | * being used to probe for service upgrade. | |
36 | * | |
37 | * (5) CULLED - The connection got summarily culled to try and free up | |
45025bce DH |
38 | * capacity. Calls currently in progress on the connection are allowed to |
39 | * continue, but new calls will have to wait. There can be no waiters in | |
40 | * this state - the conn would have to go to the WAITING state instead. | |
41 | * | |
4e255721 | 42 | * (6) IDLE - The connection has no calls in progress upon it and must have |
45025bce DH |
43 | * been exposed to the world (ie. the EXPOSED flag must be set). When it |
44 | * expires, the EXPOSED flag is cleared and the connection transitions to | |
45 | * the INACTIVE state. | |
46 | * | |
2baec2c3 | 47 | * The connection is on the rxnet->idle_client_conns list which is kept in |
45025bce DH |
48 | * order of how soon they'll expire. |
49 | * | |
50 | * There are flags of relevance to the cache: | |
51 | * | |
52 | * (1) EXPOSED - The connection ID got exposed to the world. If this flag is | |
53 | * set, an extra ref is added to the connection preventing it from being | |
54 | * reaped when it has no calls outstanding. This flag is cleared and the | |
55 | * ref dropped when a conn is discarded from the idle list. | |
56 | * | |
57 | * This allows us to move terminal call state retransmission to the | |
58 | * connection and to discard the call immediately we think it is done | |
59 | * with. It also give us a chance to reuse the connection. | |
60 | * | |
61 | * (2) DONT_REUSE - The connection should be discarded as soon as possible and | |
62 | * should not be reused. This is set when an exclusive connection is used | |
63 | * or a call ID counter overflows. | |
64 | * | |
65 | * The caching state may only be changed if the cache lock is held. | |
66 | * | |
67 | * There are two idle client connection expiry durations. If the total number | |
68 | * of connections is below the reap threshold, we use the normal duration; if | |
69 | * it's above, we use the fast duration. | |
4a3388c8 DH |
70 | */ |
71 | ||
72 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
73 | ||
74 | #include <linux/slab.h> | |
75 | #include <linux/idr.h> | |
76 | #include <linux/timer.h> | |
174cd4b1 IM |
77 | #include <linux/sched/signal.h> |
78 | ||
4a3388c8 DH |
79 | #include "ar-internal.h" |
80 | ||
45025bce DH |
81 | __read_mostly unsigned int rxrpc_max_client_connections = 1000; |
82 | __read_mostly unsigned int rxrpc_reap_client_connections = 900; | |
a158bdd3 DH |
83 | __read_mostly unsigned long rxrpc_conn_idle_client_expiry = 2 * 60 * HZ; |
84 | __read_mostly unsigned long rxrpc_conn_idle_client_fast_expiry = 2 * HZ; | |
45025bce | 85 | |
4a3388c8 DH |
86 | /* |
87 | * We use machine-unique IDs for our client connections. | |
88 | */ | |
89 | DEFINE_IDR(rxrpc_client_conn_ids); | |
90 | static DEFINE_SPINLOCK(rxrpc_conn_id_lock); | |
91 | ||
2baec2c3 | 92 | static void rxrpc_cull_active_client_conns(struct rxrpc_net *); |
45025bce | 93 | |
4a3388c8 DH |
94 | /* |
95 | * Get a connection ID and epoch for a client connection from the global pool. | |
96 | * The connection struct pointer is then recorded in the idr radix tree. The | |
090f85de DH |
97 | * epoch doesn't change until the client is rebooted (or, at least, unless the |
98 | * module is unloaded). | |
4a3388c8 | 99 | */ |
c6d2b8d7 DH |
100 | static int rxrpc_get_client_connection_id(struct rxrpc_connection *conn, |
101 | gfp_t gfp) | |
4a3388c8 | 102 | { |
2baec2c3 | 103 | struct rxrpc_net *rxnet = conn->params.local->rxnet; |
4a3388c8 DH |
104 | int id; |
105 | ||
106 | _enter(""); | |
107 | ||
108 | idr_preload(gfp); | |
4a3388c8 DH |
109 | spin_lock(&rxrpc_conn_id_lock); |
110 | ||
090f85de DH |
111 | id = idr_alloc_cyclic(&rxrpc_client_conn_ids, conn, |
112 | 1, 0x40000000, GFP_NOWAIT); | |
113 | if (id < 0) | |
114 | goto error; | |
4a3388c8 DH |
115 | |
116 | spin_unlock(&rxrpc_conn_id_lock); | |
4a3388c8 DH |
117 | idr_preload_end(); |
118 | ||
2baec2c3 | 119 | conn->proto.epoch = rxnet->epoch; |
4a3388c8 DH |
120 | conn->proto.cid = id << RXRPC_CIDSHIFT; |
121 | set_bit(RXRPC_CONN_HAS_IDR, &conn->flags); | |
090f85de | 122 | _leave(" [CID %x]", conn->proto.cid); |
4a3388c8 DH |
123 | return 0; |
124 | ||
125 | error: | |
126 | spin_unlock(&rxrpc_conn_id_lock); | |
4a3388c8 DH |
127 | idr_preload_end(); |
128 | _leave(" = %d", id); | |
129 | return id; | |
130 | } | |
131 | ||
132 | /* | |
133 | * Release a connection ID for a client connection from the global pool. | |
134 | */ | |
001c1122 | 135 | static void rxrpc_put_client_connection_id(struct rxrpc_connection *conn) |
4a3388c8 DH |
136 | { |
137 | if (test_bit(RXRPC_CONN_HAS_IDR, &conn->flags)) { | |
138 | spin_lock(&rxrpc_conn_id_lock); | |
139 | idr_remove(&rxrpc_client_conn_ids, | |
140 | conn->proto.cid >> RXRPC_CIDSHIFT); | |
141 | spin_unlock(&rxrpc_conn_id_lock); | |
142 | } | |
143 | } | |
eb9b9d22 DH |
144 | |
145 | /* | |
146 | * Destroy the client connection ID tree. | |
147 | */ | |
148 | void rxrpc_destroy_client_conn_ids(void) | |
149 | { | |
150 | struct rxrpc_connection *conn; | |
151 | int id; | |
152 | ||
153 | if (!idr_is_empty(&rxrpc_client_conn_ids)) { | |
154 | idr_for_each_entry(&rxrpc_client_conn_ids, conn, id) { | |
155 | pr_err("AF_RXRPC: Leaked client conn %p {%d}\n", | |
156 | conn, atomic_read(&conn->usage)); | |
157 | } | |
158 | BUG(); | |
159 | } | |
160 | ||
161 | idr_destroy(&rxrpc_client_conn_ids); | |
162 | } | |
c6d2b8d7 DH |
163 | |
164 | /* | |
45025bce | 165 | * Allocate a client connection. |
c6d2b8d7 DH |
166 | */ |
167 | static struct rxrpc_connection * | |
168 | rxrpc_alloc_client_connection(struct rxrpc_conn_parameters *cp, gfp_t gfp) | |
169 | { | |
170 | struct rxrpc_connection *conn; | |
2baec2c3 | 171 | struct rxrpc_net *rxnet = cp->local->rxnet; |
c6d2b8d7 DH |
172 | int ret; |
173 | ||
174 | _enter(""); | |
175 | ||
176 | conn = rxrpc_alloc_connection(gfp); | |
177 | if (!conn) { | |
178 | _leave(" = -ENOMEM"); | |
179 | return ERR_PTR(-ENOMEM); | |
180 | } | |
181 | ||
45025bce | 182 | atomic_set(&conn->usage, 1); |
8732db67 | 183 | if (cp->exclusive) |
45025bce | 184 | __set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags); |
4e255721 DH |
185 | if (cp->upgrade) |
186 | __set_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags); | |
45025bce | 187 | |
c6d2b8d7 | 188 | conn->params = *cp; |
c6d2b8d7 DH |
189 | conn->out_clientflag = RXRPC_CLIENT_INITIATED; |
190 | conn->state = RXRPC_CONN_CLIENT; | |
68d6d1ae | 191 | conn->service_id = cp->service_id; |
c6d2b8d7 | 192 | |
c6d2b8d7 DH |
193 | ret = rxrpc_get_client_connection_id(conn, gfp); |
194 | if (ret < 0) | |
195 | goto error_0; | |
196 | ||
197 | ret = rxrpc_init_client_conn_security(conn); | |
198 | if (ret < 0) | |
199 | goto error_1; | |
200 | ||
201 | ret = conn->security->prime_packet_security(conn); | |
202 | if (ret < 0) | |
203 | goto error_2; | |
204 | ||
31f5f9a1 | 205 | atomic_inc(&rxnet->nr_conns); |
2baec2c3 DH |
206 | write_lock(&rxnet->conn_lock); |
207 | list_add_tail(&conn->proc_link, &rxnet->conn_proc_list); | |
208 | write_unlock(&rxnet->conn_lock); | |
c6d2b8d7 DH |
209 | |
210 | /* We steal the caller's peer ref. */ | |
211 | cp->peer = NULL; | |
212 | rxrpc_get_local(conn->params.local); | |
213 | key_get(conn->params.key); | |
214 | ||
4c1295dc DH |
215 | trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_client, |
216 | atomic_read(&conn->usage), | |
363deeab DH |
217 | __builtin_return_address(0)); |
218 | trace_rxrpc_client(conn, -1, rxrpc_client_alloc); | |
c6d2b8d7 DH |
219 | _leave(" = %p", conn); |
220 | return conn; | |
221 | ||
222 | error_2: | |
223 | conn->security->clear(conn); | |
224 | error_1: | |
225 | rxrpc_put_client_connection_id(conn); | |
226 | error_0: | |
227 | kfree(conn); | |
228 | _leave(" = %d", ret); | |
229 | return ERR_PTR(ret); | |
230 | } | |
231 | ||
232 | /* | |
45025bce | 233 | * Determine if a connection may be reused. |
c6d2b8d7 | 234 | */ |
45025bce DH |
235 | static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn) |
236 | { | |
2baec2c3 | 237 | struct rxrpc_net *rxnet = conn->params.local->rxnet; |
45025bce DH |
238 | int id_cursor, id, distance, limit; |
239 | ||
240 | if (test_bit(RXRPC_CONN_DONT_REUSE, &conn->flags)) | |
241 | goto dont_reuse; | |
242 | ||
2baec2c3 | 243 | if (conn->proto.epoch != rxnet->epoch) |
45025bce DH |
244 | goto mark_dont_reuse; |
245 | ||
246 | /* The IDR tree gets very expensive on memory if the connection IDs are | |
247 | * widely scattered throughout the number space, so we shall want to | |
248 | * kill off connections that, say, have an ID more than about four | |
249 | * times the maximum number of client conns away from the current | |
250 | * allocation point to try and keep the IDs concentrated. | |
251 | */ | |
44430612 | 252 | id_cursor = idr_get_cursor(&rxrpc_client_conn_ids); |
45025bce DH |
253 | id = conn->proto.cid >> RXRPC_CIDSHIFT; |
254 | distance = id - id_cursor; | |
255 | if (distance < 0) | |
256 | distance = -distance; | |
44430612 | 257 | limit = max(rxrpc_max_client_connections * 4, 1024U); |
45025bce DH |
258 | if (distance > limit) |
259 | goto mark_dont_reuse; | |
260 | ||
261 | return true; | |
262 | ||
263 | mark_dont_reuse: | |
264 | set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags); | |
265 | dont_reuse: | |
266 | return false; | |
267 | } | |
268 | ||
269 | /* | |
270 | * Create or find a client connection to use for a call. | |
271 | * | |
272 | * If we return with a connection, the call will be on its waiting list. It's | |
273 | * left to the caller to assign a channel and wake up the call. | |
274 | */ | |
5e33a23b DH |
275 | static int rxrpc_get_client_conn(struct rxrpc_sock *rx, |
276 | struct rxrpc_call *call, | |
45025bce DH |
277 | struct rxrpc_conn_parameters *cp, |
278 | struct sockaddr_rxrpc *srx, | |
279 | gfp_t gfp) | |
c6d2b8d7 DH |
280 | { |
281 | struct rxrpc_connection *conn, *candidate = NULL; | |
282 | struct rxrpc_local *local = cp->local; | |
283 | struct rb_node *p, **pp, *parent; | |
284 | long diff; | |
45025bce | 285 | int ret = -ENOMEM; |
c6d2b8d7 DH |
286 | |
287 | _enter("{%d,%lx},", call->debug_id, call->user_call_ID); | |
288 | ||
5e33a23b | 289 | cp->peer = rxrpc_lookup_peer(rx, cp->local, srx, gfp); |
c6d2b8d7 | 290 | if (!cp->peer) |
45025bce | 291 | goto error; |
c6d2b8d7 | 292 | |
f7aec129 DH |
293 | call->cong_cwnd = cp->peer->cong_cwnd; |
294 | if (call->cong_cwnd >= call->cong_ssthresh) | |
295 | call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE; | |
296 | else | |
297 | call->cong_mode = RXRPC_CALL_SLOW_START; | |
298 | ||
45025bce DH |
299 | /* If the connection is not meant to be exclusive, search the available |
300 | * connections to see if the connection we want to use already exists. | |
301 | */ | |
c6d2b8d7 | 302 | if (!cp->exclusive) { |
c6d2b8d7 DH |
303 | _debug("search 1"); |
304 | spin_lock(&local->client_conns_lock); | |
305 | p = local->client_conns.rb_node; | |
306 | while (p) { | |
307 | conn = rb_entry(p, struct rxrpc_connection, client_node); | |
308 | ||
309 | #define cmp(X) ((long)conn->params.X - (long)cp->X) | |
310 | diff = (cmp(peer) ?: | |
311 | cmp(key) ?: | |
4e255721 DH |
312 | cmp(security_level) ?: |
313 | cmp(upgrade)); | |
45025bce DH |
314 | #undef cmp |
315 | if (diff < 0) { | |
c6d2b8d7 | 316 | p = p->rb_left; |
45025bce | 317 | } else if (diff > 0) { |
c6d2b8d7 | 318 | p = p->rb_right; |
45025bce DH |
319 | } else { |
320 | if (rxrpc_may_reuse_conn(conn) && | |
321 | rxrpc_get_connection_maybe(conn)) | |
322 | goto found_extant_conn; | |
323 | /* The connection needs replacing. It's better | |
324 | * to effect that when we have something to | |
325 | * replace it with so that we don't have to | |
326 | * rebalance the tree twice. | |
327 | */ | |
328 | break; | |
329 | } | |
c6d2b8d7 DH |
330 | } |
331 | spin_unlock(&local->client_conns_lock); | |
332 | } | |
333 | ||
45025bce DH |
334 | /* There wasn't a connection yet or we need an exclusive connection. |
335 | * We need to create a candidate and then potentially redo the search | |
336 | * in case we're racing with another thread also trying to connect on a | |
337 | * shareable connection. | |
338 | */ | |
339 | _debug("new conn"); | |
c6d2b8d7 | 340 | candidate = rxrpc_alloc_client_connection(cp, gfp); |
45025bce DH |
341 | if (IS_ERR(candidate)) { |
342 | ret = PTR_ERR(candidate); | |
343 | goto error_peer; | |
c6d2b8d7 DH |
344 | } |
345 | ||
45025bce DH |
346 | /* Add the call to the new connection's waiting list in case we're |
347 | * going to have to wait for the connection to come live. It's our | |
348 | * connection, so we want first dibs on the channel slots. We would | |
349 | * normally have to take channel_lock but we do this before anyone else | |
350 | * can see the connection. | |
351 | */ | |
69ffaebb | 352 | list_add(&call->chan_wait_link, &candidate->waiting_calls); |
45025bce | 353 | |
c6d2b8d7 | 354 | if (cp->exclusive) { |
45025bce | 355 | call->conn = candidate; |
91fcfbe8 | 356 | call->security = candidate->security; |
278ac0cd | 357 | call->security_ix = candidate->security_ix; |
68d6d1ae | 358 | call->service_id = candidate->service_id; |
45025bce DH |
359 | _leave(" = 0 [exclusive %d]", candidate->debug_id); |
360 | return 0; | |
c6d2b8d7 DH |
361 | } |
362 | ||
45025bce DH |
363 | /* Publish the new connection for userspace to find. We need to redo |
364 | * the search before doing this lest we race with someone else adding a | |
365 | * conflicting instance. | |
c6d2b8d7 DH |
366 | */ |
367 | _debug("search 2"); | |
368 | spin_lock(&local->client_conns_lock); | |
369 | ||
370 | pp = &local->client_conns.rb_node; | |
371 | parent = NULL; | |
372 | while (*pp) { | |
373 | parent = *pp; | |
374 | conn = rb_entry(parent, struct rxrpc_connection, client_node); | |
375 | ||
45025bce | 376 | #define cmp(X) ((long)conn->params.X - (long)candidate->params.X) |
c6d2b8d7 DH |
377 | diff = (cmp(peer) ?: |
378 | cmp(key) ?: | |
4e255721 DH |
379 | cmp(security_level) ?: |
380 | cmp(upgrade)); | |
45025bce DH |
381 | #undef cmp |
382 | if (diff < 0) { | |
c6d2b8d7 | 383 | pp = &(*pp)->rb_left; |
45025bce | 384 | } else if (diff > 0) { |
c6d2b8d7 | 385 | pp = &(*pp)->rb_right; |
45025bce DH |
386 | } else { |
387 | if (rxrpc_may_reuse_conn(conn) && | |
388 | rxrpc_get_connection_maybe(conn)) | |
389 | goto found_extant_conn; | |
390 | /* The old connection is from an outdated epoch. */ | |
391 | _debug("replace conn"); | |
392 | clear_bit(RXRPC_CONN_IN_CLIENT_CONNS, &conn->flags); | |
393 | rb_replace_node(&conn->client_node, | |
394 | &candidate->client_node, | |
395 | &local->client_conns); | |
363deeab | 396 | trace_rxrpc_client(conn, -1, rxrpc_client_replace); |
45025bce DH |
397 | goto candidate_published; |
398 | } | |
c6d2b8d7 DH |
399 | } |
400 | ||
c6d2b8d7 | 401 | _debug("new conn"); |
001c1122 DH |
402 | rb_link_node(&candidate->client_node, parent, pp); |
403 | rb_insert_color(&candidate->client_node, &local->client_conns); | |
c6d2b8d7 | 404 | |
45025bce DH |
405 | candidate_published: |
406 | set_bit(RXRPC_CONN_IN_CLIENT_CONNS, &candidate->flags); | |
407 | call->conn = candidate; | |
91fcfbe8 | 408 | call->security = candidate->security; |
278ac0cd | 409 | call->security_ix = candidate->security_ix; |
68d6d1ae | 410 | call->service_id = candidate->service_id; |
c6d2b8d7 | 411 | spin_unlock(&local->client_conns_lock); |
45025bce DH |
412 | _leave(" = 0 [new %d]", candidate->debug_id); |
413 | return 0; | |
c6d2b8d7 | 414 | |
45025bce DH |
415 | /* We come here if we found a suitable connection already in existence. |
416 | * Discard any candidate we may have allocated, and try to get a | |
417 | * channel on this one. | |
418 | */ | |
419 | found_extant_conn: | |
420 | _debug("found conn"); | |
421 | spin_unlock(&local->client_conns_lock); | |
c6d2b8d7 | 422 | |
363deeab DH |
423 | if (candidate) { |
424 | trace_rxrpc_client(candidate, -1, rxrpc_client_duplicate); | |
425 | rxrpc_put_connection(candidate); | |
426 | candidate = NULL; | |
427 | } | |
c6d2b8d7 | 428 | |
45025bce DH |
429 | spin_lock(&conn->channel_lock); |
430 | call->conn = conn; | |
91fcfbe8 | 431 | call->security = conn->security; |
278ac0cd | 432 | call->security_ix = conn->security_ix; |
68d6d1ae | 433 | call->service_id = conn->service_id; |
69ffaebb | 434 | list_add_tail(&call->chan_wait_link, &conn->waiting_calls); |
c6d2b8d7 | 435 | spin_unlock(&conn->channel_lock); |
45025bce DH |
436 | _leave(" = 0 [extant %d]", conn->debug_id); |
437 | return 0; | |
438 | ||
439 | error_peer: | |
c6d2b8d7 DH |
440 | rxrpc_put_peer(cp->peer); |
441 | cp->peer = NULL; | |
45025bce DH |
442 | error: |
443 | _leave(" = %d", ret); | |
444 | return ret; | |
445 | } | |
c6d2b8d7 | 446 | |
45025bce DH |
447 | /* |
448 | * Activate a connection. | |
449 | */ | |
2baec2c3 DH |
450 | static void rxrpc_activate_conn(struct rxrpc_net *rxnet, |
451 | struct rxrpc_connection *conn) | |
45025bce | 452 | { |
4e255721 DH |
453 | if (test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags)) { |
454 | trace_rxrpc_client(conn, -1, rxrpc_client_to_upgrade); | |
455 | conn->cache_state = RXRPC_CONN_CLIENT_UPGRADE; | |
456 | } else { | |
457 | trace_rxrpc_client(conn, -1, rxrpc_client_to_active); | |
458 | conn->cache_state = RXRPC_CONN_CLIENT_ACTIVE; | |
459 | } | |
2baec2c3 DH |
460 | rxnet->nr_active_client_conns++; |
461 | list_move_tail(&conn->cache_link, &rxnet->active_client_conns); | |
45025bce DH |
462 | } |
463 | ||
464 | /* | |
465 | * Attempt to animate a connection for a new call. | |
466 | * | |
467 | * If it's not exclusive, the connection is in the endpoint tree, and we're in | |
468 | * the conn's list of those waiting to grab a channel. There is, however, a | |
469 | * limit on the number of live connections allowed at any one time, so we may | |
470 | * have to wait for capacity to become available. | |
471 | * | |
472 | * Note that a connection on the waiting queue might *also* have active | |
473 | * channels if it has been culled to make space and then re-requested by a new | |
474 | * call. | |
475 | */ | |
2baec2c3 DH |
476 | static void rxrpc_animate_client_conn(struct rxrpc_net *rxnet, |
477 | struct rxrpc_connection *conn) | |
45025bce DH |
478 | { |
479 | unsigned int nr_conns; | |
480 | ||
481 | _enter("%d,%d", conn->debug_id, conn->cache_state); | |
482 | ||
4e255721 DH |
483 | if (conn->cache_state == RXRPC_CONN_CLIENT_ACTIVE || |
484 | conn->cache_state == RXRPC_CONN_CLIENT_UPGRADE) | |
45025bce DH |
485 | goto out; |
486 | ||
2baec2c3 | 487 | spin_lock(&rxnet->client_conn_cache_lock); |
45025bce | 488 | |
2baec2c3 | 489 | nr_conns = rxnet->nr_client_conns; |
363deeab DH |
490 | if (!test_and_set_bit(RXRPC_CONN_COUNTED, &conn->flags)) { |
491 | trace_rxrpc_client(conn, -1, rxrpc_client_count); | |
2baec2c3 | 492 | rxnet->nr_client_conns = nr_conns + 1; |
363deeab | 493 | } |
45025bce DH |
494 | |
495 | switch (conn->cache_state) { | |
496 | case RXRPC_CONN_CLIENT_ACTIVE: | |
4e255721 | 497 | case RXRPC_CONN_CLIENT_UPGRADE: |
45025bce DH |
498 | case RXRPC_CONN_CLIENT_WAITING: |
499 | break; | |
500 | ||
501 | case RXRPC_CONN_CLIENT_INACTIVE: | |
502 | case RXRPC_CONN_CLIENT_CULLED: | |
503 | case RXRPC_CONN_CLIENT_IDLE: | |
504 | if (nr_conns >= rxrpc_max_client_connections) | |
505 | goto wait_for_capacity; | |
506 | goto activate_conn; | |
507 | ||
508 | default: | |
509 | BUG(); | |
001c1122 DH |
510 | } |
511 | ||
45025bce | 512 | out_unlock: |
2baec2c3 | 513 | spin_unlock(&rxnet->client_conn_cache_lock); |
45025bce DH |
514 | out: |
515 | _leave(" [%d]", conn->cache_state); | |
516 | return; | |
c6d2b8d7 | 517 | |
45025bce DH |
518 | activate_conn: |
519 | _debug("activate"); | |
2baec2c3 | 520 | rxrpc_activate_conn(rxnet, conn); |
45025bce DH |
521 | goto out_unlock; |
522 | ||
523 | wait_for_capacity: | |
524 | _debug("wait"); | |
363deeab | 525 | trace_rxrpc_client(conn, -1, rxrpc_client_to_waiting); |
45025bce | 526 | conn->cache_state = RXRPC_CONN_CLIENT_WAITING; |
2baec2c3 | 527 | list_move_tail(&conn->cache_link, &rxnet->waiting_client_conns); |
45025bce DH |
528 | goto out_unlock; |
529 | } | |
530 | ||
531 | /* | |
532 | * Deactivate a channel. | |
533 | */ | |
534 | static void rxrpc_deactivate_one_channel(struct rxrpc_connection *conn, | |
535 | unsigned int channel) | |
536 | { | |
537 | struct rxrpc_channel *chan = &conn->channels[channel]; | |
538 | ||
539 | rcu_assign_pointer(chan->call, NULL); | |
540 | conn->active_chans &= ~(1 << channel); | |
541 | } | |
542 | ||
543 | /* | |
544 | * Assign a channel to the call at the front of the queue and wake the call up. | |
545 | * We don't increment the callNumber counter until this number has been exposed | |
546 | * to the world. | |
547 | */ | |
548 | static void rxrpc_activate_one_channel(struct rxrpc_connection *conn, | |
549 | unsigned int channel) | |
550 | { | |
551 | struct rxrpc_channel *chan = &conn->channels[channel]; | |
552 | struct rxrpc_call *call = list_entry(conn->waiting_calls.next, | |
553 | struct rxrpc_call, chan_wait_link); | |
554 | u32 call_id = chan->call_counter + 1; | |
555 | ||
363deeab DH |
556 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_activate); |
557 | ||
3136ef49 DH |
558 | /* Cancel the final ACK on the previous call if it hasn't been sent yet |
559 | * as the DATA packet will implicitly ACK it. | |
560 | */ | |
561 | clear_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags); | |
562 | ||
af338a9e | 563 | write_lock_bh(&call->state_lock); |
e122d845 | 564 | call->state = RXRPC_CALL_CLIENT_SEND_REQUEST; |
af338a9e DH |
565 | write_unlock_bh(&call->state_lock); |
566 | ||
e34d4234 | 567 | rxrpc_see_call(call); |
45025bce DH |
568 | list_del_init(&call->chan_wait_link); |
569 | conn->active_chans |= 1 << channel; | |
570 | call->peer = rxrpc_get_peer(conn->params.peer); | |
571 | call->cid = conn->proto.cid | channel; | |
572 | call->call_id = call_id; | |
573 | ||
89ca6948 | 574 | trace_rxrpc_connect_call(call); |
45025bce DH |
575 | _net("CONNECT call %08x:%08x as call %d on conn %d", |
576 | call->cid, call->call_id, call->debug_id, conn->debug_id); | |
577 | ||
578 | /* Paired with the read barrier in rxrpc_wait_for_channel(). This | |
579 | * orders cid and epoch in the connection wrt to call_id without the | |
580 | * need to take the channel_lock. | |
581 | * | |
582 | * We provisionally assign a callNumber at this point, but we don't | |
583 | * confirm it until the call is about to be exposed. | |
584 | * | |
585 | * TODO: Pair with a barrier in the data_ready handler when that looks | |
586 | * at the call ID through a connection channel. | |
587 | */ | |
588 | smp_wmb(); | |
589 | chan->call_id = call_id; | |
4764c0da | 590 | chan->call_debug_id = call->debug_id; |
45025bce DH |
591 | rcu_assign_pointer(chan->call, call); |
592 | wake_up(&call->waitq); | |
593 | } | |
594 | ||
2629c7fa DH |
595 | /* |
596 | * Assign channels and callNumbers to waiting calls with channel_lock | |
597 | * held by caller. | |
598 | */ | |
599 | static void rxrpc_activate_channels_locked(struct rxrpc_connection *conn) | |
600 | { | |
601 | u8 avail, mask; | |
602 | ||
603 | switch (conn->cache_state) { | |
604 | case RXRPC_CONN_CLIENT_ACTIVE: | |
605 | mask = RXRPC_ACTIVE_CHANS_MASK; | |
606 | break; | |
4e255721 DH |
607 | case RXRPC_CONN_CLIENT_UPGRADE: |
608 | mask = 0x01; | |
609 | break; | |
2629c7fa DH |
610 | default: |
611 | return; | |
612 | } | |
613 | ||
614 | while (!list_empty(&conn->waiting_calls) && | |
615 | (avail = ~conn->active_chans, | |
616 | avail &= mask, | |
617 | avail != 0)) | |
618 | rxrpc_activate_one_channel(conn, __ffs(avail)); | |
619 | } | |
620 | ||
45025bce DH |
621 | /* |
622 | * Assign channels and callNumbers to waiting calls. | |
623 | */ | |
624 | static void rxrpc_activate_channels(struct rxrpc_connection *conn) | |
625 | { | |
45025bce DH |
626 | _enter("%d", conn->debug_id); |
627 | ||
363deeab DH |
628 | trace_rxrpc_client(conn, -1, rxrpc_client_activate_chans); |
629 | ||
2629c7fa | 630 | if (conn->active_chans == RXRPC_ACTIVE_CHANS_MASK) |
45025bce DH |
631 | return; |
632 | ||
633 | spin_lock(&conn->channel_lock); | |
2629c7fa | 634 | rxrpc_activate_channels_locked(conn); |
45025bce DH |
635 | spin_unlock(&conn->channel_lock); |
636 | _leave(""); | |
637 | } | |
638 | ||
639 | /* | |
640 | * Wait for a callNumber and a channel to be granted to a call. | |
641 | */ | |
642 | static int rxrpc_wait_for_channel(struct rxrpc_call *call, gfp_t gfp) | |
643 | { | |
644 | int ret = 0; | |
645 | ||
646 | _enter("%d", call->debug_id); | |
647 | ||
648 | if (!call->call_id) { | |
649 | DECLARE_WAITQUEUE(myself, current); | |
c6d2b8d7 | 650 | |
c6d2b8d7 | 651 | if (!gfpflags_allow_blocking(gfp)) { |
45025bce DH |
652 | ret = -EAGAIN; |
653 | goto out; | |
c6d2b8d7 DH |
654 | } |
655 | ||
45025bce | 656 | add_wait_queue_exclusive(&call->waitq, &myself); |
c6d2b8d7 | 657 | for (;;) { |
e138aa7d DH |
658 | switch (call->interruptibility) { |
659 | case RXRPC_INTERRUPTIBLE: | |
660 | case RXRPC_PREINTERRUPTIBLE: | |
b960a34b | 661 | set_current_state(TASK_INTERRUPTIBLE); |
e138aa7d DH |
662 | break; |
663 | case RXRPC_UNINTERRUPTIBLE: | |
664 | default: | |
b960a34b | 665 | set_current_state(TASK_UNINTERRUPTIBLE); |
e138aa7d DH |
666 | break; |
667 | } | |
45025bce DH |
668 | if (call->call_id) |
669 | break; | |
e138aa7d DH |
670 | if ((call->interruptibility == RXRPC_INTERRUPTIBLE || |
671 | call->interruptibility == RXRPC_PREINTERRUPTIBLE) && | |
b960a34b | 672 | signal_pending(current)) { |
45025bce | 673 | ret = -ERESTARTSYS; |
c6d2b8d7 | 674 | break; |
45025bce | 675 | } |
c6d2b8d7 DH |
676 | schedule(); |
677 | } | |
45025bce | 678 | remove_wait_queue(&call->waitq, &myself); |
c6d2b8d7 DH |
679 | __set_current_state(TASK_RUNNING); |
680 | } | |
681 | ||
45025bce DH |
682 | /* Paired with the write barrier in rxrpc_activate_one_channel(). */ |
683 | smp_rmb(); | |
684 | ||
685 | out: | |
686 | _leave(" = %d", ret); | |
687 | return ret; | |
688 | } | |
689 | ||
690 | /* | |
691 | * find a connection for a call | |
692 | * - called in process context with IRQs enabled | |
693 | */ | |
5e33a23b DH |
694 | int rxrpc_connect_call(struct rxrpc_sock *rx, |
695 | struct rxrpc_call *call, | |
45025bce DH |
696 | struct rxrpc_conn_parameters *cp, |
697 | struct sockaddr_rxrpc *srx, | |
698 | gfp_t gfp) | |
699 | { | |
2baec2c3 | 700 | struct rxrpc_net *rxnet = cp->local->rxnet; |
45025bce DH |
701 | int ret; |
702 | ||
703 | _enter("{%d,%lx},", call->debug_id, call->user_call_ID); | |
704 | ||
3d18cbb7 | 705 | rxrpc_discard_expired_client_conns(&rxnet->client_conn_reaper); |
2baec2c3 | 706 | rxrpc_cull_active_client_conns(rxnet); |
45025bce | 707 | |
5e33a23b | 708 | ret = rxrpc_get_client_conn(rx, call, cp, srx, gfp); |
45025bce | 709 | if (ret < 0) |
c038a58c | 710 | goto out; |
45025bce | 711 | |
2baec2c3 | 712 | rxrpc_animate_client_conn(rxnet, call->conn); |
45025bce DH |
713 | rxrpc_activate_channels(call->conn); |
714 | ||
715 | ret = rxrpc_wait_for_channel(call, gfp); | |
c038a58c | 716 | if (ret < 0) { |
930c9f91 | 717 | trace_rxrpc_client(call->conn, ret, rxrpc_client_chan_wait_failed); |
45025bce | 718 | rxrpc_disconnect_client_call(call); |
c038a58c DH |
719 | goto out; |
720 | } | |
721 | ||
722 | spin_lock_bh(&call->conn->params.peer->lock); | |
f3344303 DH |
723 | hlist_add_head_rcu(&call->error_link, |
724 | &call->conn->params.peer->error_targets); | |
c038a58c | 725 | spin_unlock_bh(&call->conn->params.peer->lock); |
45025bce | 726 | |
c038a58c | 727 | out: |
45025bce DH |
728 | _leave(" = %d", ret); |
729 | return ret; | |
730 | } | |
731 | ||
732 | /* | |
733 | * Note that a connection is about to be exposed to the world. Once it is | |
734 | * exposed, we maintain an extra ref on it that stops it from being summarily | |
735 | * discarded before it's (a) had a chance to deal with retransmission and (b) | |
736 | * had a chance at re-use (the per-connection security negotiation is | |
737 | * expensive). | |
738 | */ | |
363deeab DH |
739 | static void rxrpc_expose_client_conn(struct rxrpc_connection *conn, |
740 | unsigned int channel) | |
45025bce | 741 | { |
363deeab DH |
742 | if (!test_and_set_bit(RXRPC_CONN_EXPOSED, &conn->flags)) { |
743 | trace_rxrpc_client(conn, channel, rxrpc_client_exposed); | |
45025bce | 744 | rxrpc_get_connection(conn); |
363deeab | 745 | } |
45025bce DH |
746 | } |
747 | ||
748 | /* | |
749 | * Note that a call, and thus a connection, is about to be exposed to the | |
750 | * world. | |
751 | */ | |
752 | void rxrpc_expose_client_call(struct rxrpc_call *call) | |
753 | { | |
363deeab | 754 | unsigned int channel = call->cid & RXRPC_CHANNELMASK; |
45025bce | 755 | struct rxrpc_connection *conn = call->conn; |
363deeab | 756 | struct rxrpc_channel *chan = &conn->channels[channel]; |
45025bce DH |
757 | |
758 | if (!test_and_set_bit(RXRPC_CALL_EXPOSED, &call->flags)) { | |
759 | /* Mark the call ID as being used. If the callNumber counter | |
760 | * exceeds ~2 billion, we kill the connection after its | |
761 | * outstanding calls have finished so that the counter doesn't | |
762 | * wrap. | |
763 | */ | |
764 | chan->call_counter++; | |
765 | if (chan->call_counter >= INT_MAX) | |
766 | set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags); | |
363deeab | 767 | rxrpc_expose_client_conn(conn, channel); |
45025bce DH |
768 | } |
769 | } | |
770 | ||
3d18cbb7 DH |
771 | /* |
772 | * Set the reap timer. | |
773 | */ | |
774 | static void rxrpc_set_client_reap_timer(struct rxrpc_net *rxnet) | |
775 | { | |
776 | unsigned long now = jiffies; | |
777 | unsigned long reap_at = now + rxrpc_conn_idle_client_expiry; | |
778 | ||
779 | if (rxnet->live) | |
780 | timer_reduce(&rxnet->client_conn_reap_timer, reap_at); | |
781 | } | |
782 | ||
45025bce DH |
783 | /* |
784 | * Disconnect a client call. | |
785 | */ | |
786 | void rxrpc_disconnect_client_call(struct rxrpc_call *call) | |
787 | { | |
45025bce | 788 | struct rxrpc_connection *conn = call->conn; |
930c9f91 | 789 | struct rxrpc_channel *chan = NULL; |
88f2a825 | 790 | struct rxrpc_net *rxnet = conn->params.local->rxnet; |
930c9f91 DH |
791 | unsigned int channel = -1; |
792 | u32 cid; | |
45025bce | 793 | |
930c9f91 | 794 | spin_lock(&conn->channel_lock); |
5273a191 | 795 | set_bit(RXRPC_CALL_DISCONNECTED, &call->flags); |
930c9f91 DH |
796 | |
797 | cid = call->cid; | |
798 | if (cid) { | |
799 | channel = cid & RXRPC_CHANNELMASK; | |
800 | chan = &conn->channels[channel]; | |
801 | } | |
363deeab | 802 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_disconnect); |
45025bce | 803 | |
45025bce DH |
804 | /* Calls that have never actually been assigned a channel can simply be |
805 | * discarded. If the conn didn't get used either, it will follow | |
806 | * immediately unless someone else grabs it in the meantime. | |
807 | */ | |
808 | if (!list_empty(&call->chan_wait_link)) { | |
809 | _debug("call is waiting"); | |
810 | ASSERTCMP(call->call_id, ==, 0); | |
811 | ASSERT(!test_bit(RXRPC_CALL_EXPOSED, &call->flags)); | |
812 | list_del_init(&call->chan_wait_link); | |
813 | ||
363deeab DH |
814 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_unstarted); |
815 | ||
45025bce DH |
816 | /* We must deactivate or idle the connection if it's now |
817 | * waiting for nothing. | |
818 | */ | |
2baec2c3 | 819 | spin_lock(&rxnet->client_conn_cache_lock); |
45025bce DH |
820 | if (conn->cache_state == RXRPC_CONN_CLIENT_WAITING && |
821 | list_empty(&conn->waiting_calls) && | |
822 | !conn->active_chans) | |
823 | goto idle_connection; | |
824 | goto out; | |
825 | } | |
826 | ||
930c9f91 DH |
827 | if (rcu_access_pointer(chan->call) != call) { |
828 | spin_unlock(&conn->channel_lock); | |
829 | BUG(); | |
830 | } | |
45025bce DH |
831 | |
832 | /* If a client call was exposed to the world, we save the result for | |
833 | * retransmission. | |
834 | * | |
835 | * We use a barrier here so that the call number and abort code can be | |
836 | * read without needing to take a lock. | |
837 | * | |
838 | * TODO: Make the incoming packet handler check this and handle | |
839 | * terminal retransmission without requiring access to the call. | |
840 | */ | |
841 | if (test_bit(RXRPC_CALL_EXPOSED, &call->flags)) { | |
f5c17aae | 842 | _debug("exposed %u,%u", call->call_id, call->abort_code); |
45025bce DH |
843 | __rxrpc_disconnect_call(conn, call); |
844 | } | |
845 | ||
846 | /* See if we can pass the channel directly to another call. */ | |
847 | if (conn->cache_state == RXRPC_CONN_CLIENT_ACTIVE && | |
848 | !list_empty(&conn->waiting_calls)) { | |
363deeab | 849 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass); |
45025bce DH |
850 | rxrpc_activate_one_channel(conn, channel); |
851 | goto out_2; | |
852 | } | |
853 | ||
3136ef49 DH |
854 | /* Schedule the final ACK to be transmitted in a short while so that it |
855 | * can be skipped if we find a follow-on call. The first DATA packet | |
856 | * of the follow on call will implicitly ACK this call. | |
857 | */ | |
17e9e23b DH |
858 | if (call->completion == RXRPC_CALL_SUCCEEDED && |
859 | test_bit(RXRPC_CALL_EXPOSED, &call->flags)) { | |
3136ef49 DH |
860 | unsigned long final_ack_at = jiffies + 2; |
861 | ||
862 | WRITE_ONCE(chan->final_ack_at, final_ack_at); | |
863 | smp_wmb(); /* vs rxrpc_process_delayed_final_acks() */ | |
864 | set_bit(RXRPC_CONN_FINAL_ACK_0 + channel, &conn->flags); | |
865 | rxrpc_reduce_conn_timer(conn, final_ack_at); | |
866 | } | |
867 | ||
45025bce DH |
868 | /* Things are more complex and we need the cache lock. We might be |
869 | * able to simply idle the conn or it might now be lurking on the wait | |
870 | * list. It might even get moved back to the active list whilst we're | |
871 | * waiting for the lock. | |
872 | */ | |
2baec2c3 | 873 | spin_lock(&rxnet->client_conn_cache_lock); |
45025bce DH |
874 | |
875 | switch (conn->cache_state) { | |
4e255721 DH |
876 | case RXRPC_CONN_CLIENT_UPGRADE: |
877 | /* Deal with termination of a service upgrade probe. */ | |
878 | if (test_bit(RXRPC_CONN_EXPOSED, &conn->flags)) { | |
879 | clear_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags); | |
880 | trace_rxrpc_client(conn, channel, rxrpc_client_to_active); | |
881 | conn->cache_state = RXRPC_CONN_CLIENT_ACTIVE; | |
882 | rxrpc_activate_channels_locked(conn); | |
883 | } | |
df561f66 | 884 | fallthrough; |
45025bce DH |
885 | case RXRPC_CONN_CLIENT_ACTIVE: |
886 | if (list_empty(&conn->waiting_calls)) { | |
887 | rxrpc_deactivate_one_channel(conn, channel); | |
888 | if (!conn->active_chans) { | |
2baec2c3 | 889 | rxnet->nr_active_client_conns--; |
45025bce DH |
890 | goto idle_connection; |
891 | } | |
892 | goto out; | |
893 | } | |
894 | ||
363deeab | 895 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass); |
45025bce DH |
896 | rxrpc_activate_one_channel(conn, channel); |
897 | goto out; | |
898 | ||
899 | case RXRPC_CONN_CLIENT_CULLED: | |
900 | rxrpc_deactivate_one_channel(conn, channel); | |
901 | ASSERT(list_empty(&conn->waiting_calls)); | |
902 | if (!conn->active_chans) | |
903 | goto idle_connection; | |
904 | goto out; | |
905 | ||
906 | case RXRPC_CONN_CLIENT_WAITING: | |
907 | rxrpc_deactivate_one_channel(conn, channel); | |
908 | goto out; | |
909 | ||
910 | default: | |
911 | BUG(); | |
912 | } | |
c6d2b8d7 | 913 | |
45025bce | 914 | out: |
2baec2c3 | 915 | spin_unlock(&rxnet->client_conn_cache_lock); |
45025bce DH |
916 | out_2: |
917 | spin_unlock(&conn->channel_lock); | |
45025bce DH |
918 | _leave(""); |
919 | return; | |
920 | ||
921 | idle_connection: | |
922 | /* As no channels remain active, the connection gets deactivated | |
923 | * immediately or moved to the idle list for a short while. | |
924 | */ | |
925 | if (test_bit(RXRPC_CONN_EXPOSED, &conn->flags)) { | |
363deeab | 926 | trace_rxrpc_client(conn, channel, rxrpc_client_to_idle); |
45025bce DH |
927 | conn->idle_timestamp = jiffies; |
928 | conn->cache_state = RXRPC_CONN_CLIENT_IDLE; | |
2baec2c3 DH |
929 | list_move_tail(&conn->cache_link, &rxnet->idle_client_conns); |
930 | if (rxnet->idle_client_conns.next == &conn->cache_link && | |
931 | !rxnet->kill_all_client_conns) | |
3d18cbb7 | 932 | rxrpc_set_client_reap_timer(rxnet); |
45025bce | 933 | } else { |
363deeab | 934 | trace_rxrpc_client(conn, channel, rxrpc_client_to_inactive); |
45025bce DH |
935 | conn->cache_state = RXRPC_CONN_CLIENT_INACTIVE; |
936 | list_del_init(&conn->cache_link); | |
937 | } | |
938 | goto out; | |
c6d2b8d7 | 939 | } |
001c1122 DH |
940 | |
941 | /* | |
45025bce | 942 | * Clean up a dead client connection. |
001c1122 | 943 | */ |
45025bce DH |
944 | static struct rxrpc_connection * |
945 | rxrpc_put_one_client_conn(struct rxrpc_connection *conn) | |
001c1122 | 946 | { |
66d58af7 | 947 | struct rxrpc_connection *next = NULL; |
001c1122 | 948 | struct rxrpc_local *local = conn->params.local; |
2baec2c3 | 949 | struct rxrpc_net *rxnet = local->rxnet; |
45025bce | 950 | unsigned int nr_conns; |
001c1122 | 951 | |
363deeab DH |
952 | trace_rxrpc_client(conn, -1, rxrpc_client_cleanup); |
953 | ||
45025bce DH |
954 | if (test_bit(RXRPC_CONN_IN_CLIENT_CONNS, &conn->flags)) { |
955 | spin_lock(&local->client_conns_lock); | |
956 | if (test_and_clear_bit(RXRPC_CONN_IN_CLIENT_CONNS, | |
957 | &conn->flags)) | |
958 | rb_erase(&conn->client_node, &local->client_conns); | |
959 | spin_unlock(&local->client_conns_lock); | |
960 | } | |
001c1122 DH |
961 | |
962 | rxrpc_put_client_connection_id(conn); | |
45025bce DH |
963 | |
964 | ASSERTCMP(conn->cache_state, ==, RXRPC_CONN_CLIENT_INACTIVE); | |
965 | ||
66d58af7 | 966 | if (test_bit(RXRPC_CONN_COUNTED, &conn->flags)) { |
363deeab | 967 | trace_rxrpc_client(conn, -1, rxrpc_client_uncount); |
2baec2c3 DH |
968 | spin_lock(&rxnet->client_conn_cache_lock); |
969 | nr_conns = --rxnet->nr_client_conns; | |
66d58af7 DH |
970 | |
971 | if (nr_conns < rxrpc_max_client_connections && | |
2baec2c3 DH |
972 | !list_empty(&rxnet->waiting_client_conns)) { |
973 | next = list_entry(rxnet->waiting_client_conns.next, | |
66d58af7 DH |
974 | struct rxrpc_connection, cache_link); |
975 | rxrpc_get_connection(next); | |
2baec2c3 | 976 | rxrpc_activate_conn(rxnet, next); |
66d58af7 | 977 | } |
45025bce | 978 | |
2baec2c3 | 979 | spin_unlock(&rxnet->client_conn_cache_lock); |
45025bce DH |
980 | } |
981 | ||
45025bce | 982 | rxrpc_kill_connection(conn); |
45025bce DH |
983 | if (next) |
984 | rxrpc_activate_channels(next); | |
985 | ||
986 | /* We need to get rid of the temporary ref we took upon next, but we | |
987 | * can't call rxrpc_put_connection() recursively. | |
988 | */ | |
989 | return next; | |
990 | } | |
991 | ||
992 | /* | |
993 | * Clean up a dead client connections. | |
994 | */ | |
995 | void rxrpc_put_client_conn(struct rxrpc_connection *conn) | |
996 | { | |
363deeab | 997 | const void *here = __builtin_return_address(0); |
4c1295dc | 998 | unsigned int debug_id = conn->debug_id; |
363deeab | 999 | int n; |
45025bce DH |
1000 | |
1001 | do { | |
363deeab | 1002 | n = atomic_dec_return(&conn->usage); |
4c1295dc | 1003 | trace_rxrpc_conn(debug_id, rxrpc_conn_put_client, n, here); |
363deeab DH |
1004 | if (n > 0) |
1005 | return; | |
1006 | ASSERTCMP(n, >=, 0); | |
1007 | ||
1008 | conn = rxrpc_put_one_client_conn(conn); | |
1009 | } while (conn); | |
45025bce DH |
1010 | } |
1011 | ||
1012 | /* | |
1013 | * Kill the longest-active client connections to make room for new ones. | |
1014 | */ | |
2baec2c3 | 1015 | static void rxrpc_cull_active_client_conns(struct rxrpc_net *rxnet) |
45025bce DH |
1016 | { |
1017 | struct rxrpc_connection *conn; | |
2baec2c3 | 1018 | unsigned int nr_conns = rxnet->nr_client_conns; |
45025bce DH |
1019 | unsigned int nr_active, limit; |
1020 | ||
1021 | _enter(""); | |
1022 | ||
1023 | ASSERTCMP(nr_conns, >=, 0); | |
1024 | if (nr_conns < rxrpc_max_client_connections) { | |
1025 | _leave(" [ok]"); | |
1026 | return; | |
1027 | } | |
1028 | limit = rxrpc_reap_client_connections; | |
1029 | ||
2baec2c3 DH |
1030 | spin_lock(&rxnet->client_conn_cache_lock); |
1031 | nr_active = rxnet->nr_active_client_conns; | |
45025bce DH |
1032 | |
1033 | while (nr_active > limit) { | |
2baec2c3 DH |
1034 | ASSERT(!list_empty(&rxnet->active_client_conns)); |
1035 | conn = list_entry(rxnet->active_client_conns.next, | |
45025bce | 1036 | struct rxrpc_connection, cache_link); |
4e255721 DH |
1037 | ASSERTIFCMP(conn->cache_state != RXRPC_CONN_CLIENT_ACTIVE, |
1038 | conn->cache_state, ==, RXRPC_CONN_CLIENT_UPGRADE); | |
45025bce DH |
1039 | |
1040 | if (list_empty(&conn->waiting_calls)) { | |
363deeab | 1041 | trace_rxrpc_client(conn, -1, rxrpc_client_to_culled); |
45025bce DH |
1042 | conn->cache_state = RXRPC_CONN_CLIENT_CULLED; |
1043 | list_del_init(&conn->cache_link); | |
1044 | } else { | |
363deeab | 1045 | trace_rxrpc_client(conn, -1, rxrpc_client_to_waiting); |
45025bce DH |
1046 | conn->cache_state = RXRPC_CONN_CLIENT_WAITING; |
1047 | list_move_tail(&conn->cache_link, | |
2baec2c3 | 1048 | &rxnet->waiting_client_conns); |
45025bce DH |
1049 | } |
1050 | ||
1051 | nr_active--; | |
1052 | } | |
1053 | ||
2baec2c3 DH |
1054 | rxnet->nr_active_client_conns = nr_active; |
1055 | spin_unlock(&rxnet->client_conn_cache_lock); | |
45025bce DH |
1056 | ASSERTCMP(nr_active, >=, 0); |
1057 | _leave(" [culled]"); | |
1058 | } | |
1059 | ||
1060 | /* | |
1061 | * Discard expired client connections from the idle list. Each conn in the | |
1062 | * idle list has been exposed and holds an extra ref because of that. | |
1063 | * | |
1064 | * This may be called from conn setup or from a work item so cannot be | |
1065 | * considered non-reentrant. | |
1066 | */ | |
2baec2c3 | 1067 | void rxrpc_discard_expired_client_conns(struct work_struct *work) |
45025bce DH |
1068 | { |
1069 | struct rxrpc_connection *conn; | |
2baec2c3 | 1070 | struct rxrpc_net *rxnet = |
3d18cbb7 | 1071 | container_of(work, struct rxrpc_net, client_conn_reaper); |
45025bce DH |
1072 | unsigned long expiry, conn_expires_at, now; |
1073 | unsigned int nr_conns; | |
45025bce | 1074 | |
2baec2c3 | 1075 | _enter(""); |
45025bce | 1076 | |
2baec2c3 | 1077 | if (list_empty(&rxnet->idle_client_conns)) { |
45025bce DH |
1078 | _leave(" [empty]"); |
1079 | return; | |
1080 | } | |
1081 | ||
1082 | /* Don't double up on the discarding */ | |
2baec2c3 | 1083 | if (!spin_trylock(&rxnet->client_conn_discard_lock)) { |
45025bce DH |
1084 | _leave(" [already]"); |
1085 | return; | |
1086 | } | |
1087 | ||
1088 | /* We keep an estimate of what the number of conns ought to be after | |
1089 | * we've discarded some so that we don't overdo the discarding. | |
1090 | */ | |
2baec2c3 | 1091 | nr_conns = rxnet->nr_client_conns; |
45025bce DH |
1092 | |
1093 | next: | |
2baec2c3 | 1094 | spin_lock(&rxnet->client_conn_cache_lock); |
45025bce | 1095 | |
2baec2c3 | 1096 | if (list_empty(&rxnet->idle_client_conns)) |
45025bce DH |
1097 | goto out; |
1098 | ||
2baec2c3 | 1099 | conn = list_entry(rxnet->idle_client_conns.next, |
45025bce DH |
1100 | struct rxrpc_connection, cache_link); |
1101 | ASSERT(test_bit(RXRPC_CONN_EXPOSED, &conn->flags)); | |
1102 | ||
2baec2c3 | 1103 | if (!rxnet->kill_all_client_conns) { |
45025bce DH |
1104 | /* If the number of connections is over the reap limit, we |
1105 | * expedite discard by reducing the expiry timeout. We must, | |
1106 | * however, have at least a short grace period to be able to do | |
1107 | * final-ACK or ABORT retransmission. | |
1108 | */ | |
1109 | expiry = rxrpc_conn_idle_client_expiry; | |
1110 | if (nr_conns > rxrpc_reap_client_connections) | |
1111 | expiry = rxrpc_conn_idle_client_fast_expiry; | |
f859ab61 DH |
1112 | if (conn->params.local->service_closed) |
1113 | expiry = rxrpc_closed_conn_expiry * HZ; | |
45025bce DH |
1114 | |
1115 | conn_expires_at = conn->idle_timestamp + expiry; | |
1116 | ||
1117 | now = READ_ONCE(jiffies); | |
1118 | if (time_after(conn_expires_at, now)) | |
1119 | goto not_yet_expired; | |
1120 | } | |
1121 | ||
363deeab | 1122 | trace_rxrpc_client(conn, -1, rxrpc_client_discard); |
45025bce DH |
1123 | if (!test_and_clear_bit(RXRPC_CONN_EXPOSED, &conn->flags)) |
1124 | BUG(); | |
1125 | conn->cache_state = RXRPC_CONN_CLIENT_INACTIVE; | |
1126 | list_del_init(&conn->cache_link); | |
1127 | ||
2baec2c3 | 1128 | spin_unlock(&rxnet->client_conn_cache_lock); |
45025bce DH |
1129 | |
1130 | /* When we cleared the EXPOSED flag, we took on responsibility for the | |
1131 | * reference that that had on the usage count. We deal with that here. | |
1132 | * If someone re-sets the flag and re-gets the ref, that's fine. | |
1133 | */ | |
1134 | rxrpc_put_connection(conn); | |
45025bce DH |
1135 | nr_conns--; |
1136 | goto next; | |
1137 | ||
1138 | not_yet_expired: | |
1139 | /* The connection at the front of the queue hasn't yet expired, so | |
1140 | * schedule the work item for that point if we discarded something. | |
1141 | * | |
1142 | * We don't worry if the work item is already scheduled - it can look | |
1143 | * after rescheduling itself at a later time. We could cancel it, but | |
1144 | * then things get messier. | |
1145 | */ | |
1146 | _debug("not yet"); | |
2baec2c3 | 1147 | if (!rxnet->kill_all_client_conns) |
3d18cbb7 DH |
1148 | timer_reduce(&rxnet->client_conn_reap_timer, |
1149 | conn_expires_at); | |
45025bce DH |
1150 | |
1151 | out: | |
2baec2c3 DH |
1152 | spin_unlock(&rxnet->client_conn_cache_lock); |
1153 | spin_unlock(&rxnet->client_conn_discard_lock); | |
45025bce DH |
1154 | _leave(""); |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * Preemptively destroy all the client connection records rather than waiting | |
1159 | * for them to time out | |
1160 | */ | |
2baec2c3 | 1161 | void rxrpc_destroy_all_client_connections(struct rxrpc_net *rxnet) |
45025bce DH |
1162 | { |
1163 | _enter(""); | |
1164 | ||
2baec2c3 DH |
1165 | spin_lock(&rxnet->client_conn_cache_lock); |
1166 | rxnet->kill_all_client_conns = true; | |
1167 | spin_unlock(&rxnet->client_conn_cache_lock); | |
45025bce | 1168 | |
3d18cbb7 | 1169 | del_timer_sync(&rxnet->client_conn_reap_timer); |
45025bce | 1170 | |
3d18cbb7 | 1171 | if (!rxrpc_queue_work(&rxnet->client_conn_reaper)) |
45025bce DH |
1172 | _debug("destroy: queue failed"); |
1173 | ||
1174 | _leave(""); | |
001c1122 | 1175 | } |
d12040b6 DH |
1176 | |
1177 | /* | |
1178 | * Clean up the client connections on a local endpoint. | |
1179 | */ | |
1180 | void rxrpc_clean_up_local_conns(struct rxrpc_local *local) | |
1181 | { | |
1182 | struct rxrpc_connection *conn, *tmp; | |
1183 | struct rxrpc_net *rxnet = local->rxnet; | |
1184 | unsigned int nr_active; | |
1185 | LIST_HEAD(graveyard); | |
1186 | ||
1187 | _enter(""); | |
1188 | ||
1189 | spin_lock(&rxnet->client_conn_cache_lock); | |
1190 | nr_active = rxnet->nr_active_client_conns; | |
1191 | ||
1192 | list_for_each_entry_safe(conn, tmp, &rxnet->idle_client_conns, | |
1193 | cache_link) { | |
1194 | if (conn->params.local == local) { | |
1195 | ASSERTCMP(conn->cache_state, ==, RXRPC_CONN_CLIENT_IDLE); | |
1196 | ||
1197 | trace_rxrpc_client(conn, -1, rxrpc_client_discard); | |
1198 | if (!test_and_clear_bit(RXRPC_CONN_EXPOSED, &conn->flags)) | |
1199 | BUG(); | |
1200 | conn->cache_state = RXRPC_CONN_CLIENT_INACTIVE; | |
1201 | list_move(&conn->cache_link, &graveyard); | |
1202 | nr_active--; | |
1203 | } | |
1204 | } | |
1205 | ||
1206 | rxnet->nr_active_client_conns = nr_active; | |
1207 | spin_unlock(&rxnet->client_conn_cache_lock); | |
1208 | ASSERTCMP(nr_active, >=, 0); | |
1209 | ||
1210 | while (!list_empty(&graveyard)) { | |
1211 | conn = list_entry(graveyard.next, | |
1212 | struct rxrpc_connection, cache_link); | |
1213 | list_del_init(&conn->cache_link); | |
1214 | ||
1215 | rxrpc_put_connection(conn); | |
1216 | } | |
1217 | ||
1218 | _leave(" [culled]"); | |
1219 | } |