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4a3388c8 DH |
1 | /* Client connection-specific management code. |
2 | * | |
3 | * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public Licence | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the Licence, or (at your option) any later version. | |
45025bce DH |
10 | * |
11 | * | |
12 | * Client connections need to be cached for a little while after they've made a | |
13 | * call so as to handle retransmitted DATA packets in case the server didn't | |
14 | * receive the final ACK or terminating ABORT we sent it. | |
15 | * | |
16 | * Client connections can be in one of a number of cache states: | |
17 | * | |
18 | * (1) INACTIVE - The connection is not held in any list and may not have been | |
19 | * exposed to the world. If it has been previously exposed, it was | |
20 | * discarded from the idle list after expiring. | |
21 | * | |
22 | * (2) WAITING - The connection is waiting for the number of client conns to | |
23 | * drop below the maximum capacity. Calls may be in progress upon it from | |
24 | * when it was active and got culled. | |
25 | * | |
26 | * The connection is on the rxrpc_waiting_client_conns list which is kept | |
27 | * in to-be-granted order. Culled conns with waiters go to the back of | |
28 | * the queue just like new conns. | |
29 | * | |
30 | * (3) ACTIVE - The connection has at least one call in progress upon it, it | |
31 | * may freely grant available channels to new calls and calls may be | |
32 | * waiting on it for channels to become available. | |
33 | * | |
34 | * The connection is on the rxrpc_active_client_conns list which is kept | |
35 | * in activation order for culling purposes. | |
36 | * | |
37 | * rxrpc_nr_active_client_conns is held incremented also. | |
38 | * | |
39 | * (4) CULLED - The connection got summarily culled to try and free up | |
40 | * capacity. Calls currently in progress on the connection are allowed to | |
41 | * continue, but new calls will have to wait. There can be no waiters in | |
42 | * this state - the conn would have to go to the WAITING state instead. | |
43 | * | |
44 | * (5) IDLE - The connection has no calls in progress upon it and must have | |
45 | * been exposed to the world (ie. the EXPOSED flag must be set). When it | |
46 | * expires, the EXPOSED flag is cleared and the connection transitions to | |
47 | * the INACTIVE state. | |
48 | * | |
49 | * The connection is on the rxrpc_idle_client_conns list which is kept in | |
50 | * order of how soon they'll expire. | |
51 | * | |
52 | * There are flags of relevance to the cache: | |
53 | * | |
54 | * (1) EXPOSED - The connection ID got exposed to the world. If this flag is | |
55 | * set, an extra ref is added to the connection preventing it from being | |
56 | * reaped when it has no calls outstanding. This flag is cleared and the | |
57 | * ref dropped when a conn is discarded from the idle list. | |
58 | * | |
59 | * This allows us to move terminal call state retransmission to the | |
60 | * connection and to discard the call immediately we think it is done | |
61 | * with. It also give us a chance to reuse the connection. | |
62 | * | |
63 | * (2) DONT_REUSE - The connection should be discarded as soon as possible and | |
64 | * should not be reused. This is set when an exclusive connection is used | |
65 | * or a call ID counter overflows. | |
66 | * | |
67 | * The caching state may only be changed if the cache lock is held. | |
68 | * | |
69 | * There are two idle client connection expiry durations. If the total number | |
70 | * of connections is below the reap threshold, we use the normal duration; if | |
71 | * it's above, we use the fast duration. | |
4a3388c8 DH |
72 | */ |
73 | ||
74 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
75 | ||
76 | #include <linux/slab.h> | |
77 | #include <linux/idr.h> | |
78 | #include <linux/timer.h> | |
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; | |
83 | __read_mostly unsigned int rxrpc_conn_idle_client_expiry = 2 * 60 * HZ; | |
84 | __read_mostly unsigned int rxrpc_conn_idle_client_fast_expiry = 2 * HZ; | |
85 | ||
86 | static unsigned int rxrpc_nr_client_conns; | |
87 | static unsigned int rxrpc_nr_active_client_conns; | |
88 | static __read_mostly bool rxrpc_kill_all_client_conns; | |
89 | ||
90 | static DEFINE_SPINLOCK(rxrpc_client_conn_cache_lock); | |
91 | static DEFINE_SPINLOCK(rxrpc_client_conn_discard_mutex); | |
92 | static LIST_HEAD(rxrpc_waiting_client_conns); | |
93 | static LIST_HEAD(rxrpc_active_client_conns); | |
94 | static LIST_HEAD(rxrpc_idle_client_conns); | |
95 | ||
4a3388c8 DH |
96 | /* |
97 | * We use machine-unique IDs for our client connections. | |
98 | */ | |
99 | DEFINE_IDR(rxrpc_client_conn_ids); | |
100 | static DEFINE_SPINLOCK(rxrpc_conn_id_lock); | |
101 | ||
45025bce DH |
102 | static void rxrpc_cull_active_client_conns(void); |
103 | static void rxrpc_discard_expired_client_conns(struct work_struct *); | |
104 | ||
105 | static DECLARE_DELAYED_WORK(rxrpc_client_conn_reap, | |
106 | rxrpc_discard_expired_client_conns); | |
107 | ||
4a3388c8 DH |
108 | /* |
109 | * Get a connection ID and epoch for a client connection from the global pool. | |
110 | * The connection struct pointer is then recorded in the idr radix tree. The | |
090f85de DH |
111 | * epoch doesn't change until the client is rebooted (or, at least, unless the |
112 | * module is unloaded). | |
4a3388c8 | 113 | */ |
c6d2b8d7 DH |
114 | static int rxrpc_get_client_connection_id(struct rxrpc_connection *conn, |
115 | gfp_t gfp) | |
4a3388c8 | 116 | { |
4a3388c8 DH |
117 | int id; |
118 | ||
119 | _enter(""); | |
120 | ||
121 | idr_preload(gfp); | |
4a3388c8 DH |
122 | spin_lock(&rxrpc_conn_id_lock); |
123 | ||
090f85de DH |
124 | id = idr_alloc_cyclic(&rxrpc_client_conn_ids, conn, |
125 | 1, 0x40000000, GFP_NOWAIT); | |
126 | if (id < 0) | |
127 | goto error; | |
4a3388c8 DH |
128 | |
129 | spin_unlock(&rxrpc_conn_id_lock); | |
4a3388c8 DH |
130 | idr_preload_end(); |
131 | ||
090f85de | 132 | conn->proto.epoch = rxrpc_epoch; |
4a3388c8 DH |
133 | conn->proto.cid = id << RXRPC_CIDSHIFT; |
134 | set_bit(RXRPC_CONN_HAS_IDR, &conn->flags); | |
090f85de | 135 | _leave(" [CID %x]", conn->proto.cid); |
4a3388c8 DH |
136 | return 0; |
137 | ||
138 | error: | |
139 | spin_unlock(&rxrpc_conn_id_lock); | |
4a3388c8 DH |
140 | idr_preload_end(); |
141 | _leave(" = %d", id); | |
142 | return id; | |
143 | } | |
144 | ||
145 | /* | |
146 | * Release a connection ID for a client connection from the global pool. | |
147 | */ | |
001c1122 | 148 | static void rxrpc_put_client_connection_id(struct rxrpc_connection *conn) |
4a3388c8 DH |
149 | { |
150 | if (test_bit(RXRPC_CONN_HAS_IDR, &conn->flags)) { | |
151 | spin_lock(&rxrpc_conn_id_lock); | |
152 | idr_remove(&rxrpc_client_conn_ids, | |
153 | conn->proto.cid >> RXRPC_CIDSHIFT); | |
154 | spin_unlock(&rxrpc_conn_id_lock); | |
155 | } | |
156 | } | |
eb9b9d22 DH |
157 | |
158 | /* | |
159 | * Destroy the client connection ID tree. | |
160 | */ | |
161 | void rxrpc_destroy_client_conn_ids(void) | |
162 | { | |
163 | struct rxrpc_connection *conn; | |
164 | int id; | |
165 | ||
166 | if (!idr_is_empty(&rxrpc_client_conn_ids)) { | |
167 | idr_for_each_entry(&rxrpc_client_conn_ids, conn, id) { | |
168 | pr_err("AF_RXRPC: Leaked client conn %p {%d}\n", | |
169 | conn, atomic_read(&conn->usage)); | |
170 | } | |
171 | BUG(); | |
172 | } | |
173 | ||
174 | idr_destroy(&rxrpc_client_conn_ids); | |
175 | } | |
c6d2b8d7 DH |
176 | |
177 | /* | |
45025bce | 178 | * Allocate a client connection. |
c6d2b8d7 DH |
179 | */ |
180 | static struct rxrpc_connection * | |
181 | rxrpc_alloc_client_connection(struct rxrpc_conn_parameters *cp, gfp_t gfp) | |
182 | { | |
183 | struct rxrpc_connection *conn; | |
184 | int ret; | |
185 | ||
186 | _enter(""); | |
187 | ||
188 | conn = rxrpc_alloc_connection(gfp); | |
189 | if (!conn) { | |
190 | _leave(" = -ENOMEM"); | |
191 | return ERR_PTR(-ENOMEM); | |
192 | } | |
193 | ||
45025bce | 194 | atomic_set(&conn->usage, 1); |
8732db67 | 195 | if (cp->exclusive) |
45025bce DH |
196 | __set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags); |
197 | ||
c6d2b8d7 | 198 | conn->params = *cp; |
c6d2b8d7 DH |
199 | conn->out_clientflag = RXRPC_CLIENT_INITIATED; |
200 | conn->state = RXRPC_CONN_CLIENT; | |
201 | ||
c6d2b8d7 DH |
202 | ret = rxrpc_get_client_connection_id(conn, gfp); |
203 | if (ret < 0) | |
204 | goto error_0; | |
205 | ||
206 | ret = rxrpc_init_client_conn_security(conn); | |
207 | if (ret < 0) | |
208 | goto error_1; | |
209 | ||
210 | ret = conn->security->prime_packet_security(conn); | |
211 | if (ret < 0) | |
212 | goto error_2; | |
213 | ||
214 | write_lock(&rxrpc_connection_lock); | |
4d028b2c | 215 | list_add_tail(&conn->proc_link, &rxrpc_connection_proc_list); |
c6d2b8d7 DH |
216 | write_unlock(&rxrpc_connection_lock); |
217 | ||
218 | /* We steal the caller's peer ref. */ | |
219 | cp->peer = NULL; | |
220 | rxrpc_get_local(conn->params.local); | |
221 | key_get(conn->params.key); | |
222 | ||
363deeab DH |
223 | trace_rxrpc_conn(conn, rxrpc_conn_new_client, atomic_read(&conn->usage), |
224 | __builtin_return_address(0)); | |
225 | trace_rxrpc_client(conn, -1, rxrpc_client_alloc); | |
c6d2b8d7 DH |
226 | _leave(" = %p", conn); |
227 | return conn; | |
228 | ||
229 | error_2: | |
230 | conn->security->clear(conn); | |
231 | error_1: | |
232 | rxrpc_put_client_connection_id(conn); | |
233 | error_0: | |
234 | kfree(conn); | |
235 | _leave(" = %d", ret); | |
236 | return ERR_PTR(ret); | |
237 | } | |
238 | ||
239 | /* | |
45025bce | 240 | * Determine if a connection may be reused. |
c6d2b8d7 | 241 | */ |
45025bce DH |
242 | static bool rxrpc_may_reuse_conn(struct rxrpc_connection *conn) |
243 | { | |
244 | int id_cursor, id, distance, limit; | |
245 | ||
246 | if (test_bit(RXRPC_CONN_DONT_REUSE, &conn->flags)) | |
247 | goto dont_reuse; | |
248 | ||
249 | if (conn->proto.epoch != rxrpc_epoch) | |
250 | goto mark_dont_reuse; | |
251 | ||
252 | /* The IDR tree gets very expensive on memory if the connection IDs are | |
253 | * widely scattered throughout the number space, so we shall want to | |
254 | * kill off connections that, say, have an ID more than about four | |
255 | * times the maximum number of client conns away from the current | |
256 | * allocation point to try and keep the IDs concentrated. | |
257 | */ | |
44430612 | 258 | id_cursor = idr_get_cursor(&rxrpc_client_conn_ids); |
45025bce DH |
259 | id = conn->proto.cid >> RXRPC_CIDSHIFT; |
260 | distance = id - id_cursor; | |
261 | if (distance < 0) | |
262 | distance = -distance; | |
44430612 | 263 | limit = max(rxrpc_max_client_connections * 4, 1024U); |
45025bce DH |
264 | if (distance > limit) |
265 | goto mark_dont_reuse; | |
266 | ||
267 | return true; | |
268 | ||
269 | mark_dont_reuse: | |
270 | set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags); | |
271 | dont_reuse: | |
272 | return false; | |
273 | } | |
274 | ||
275 | /* | |
276 | * Create or find a client connection to use for a call. | |
277 | * | |
278 | * If we return with a connection, the call will be on its waiting list. It's | |
279 | * left to the caller to assign a channel and wake up the call. | |
280 | */ | |
281 | static int rxrpc_get_client_conn(struct rxrpc_call *call, | |
282 | struct rxrpc_conn_parameters *cp, | |
283 | struct sockaddr_rxrpc *srx, | |
284 | gfp_t gfp) | |
c6d2b8d7 DH |
285 | { |
286 | struct rxrpc_connection *conn, *candidate = NULL; | |
287 | struct rxrpc_local *local = cp->local; | |
288 | struct rb_node *p, **pp, *parent; | |
289 | long diff; | |
45025bce | 290 | int ret = -ENOMEM; |
c6d2b8d7 DH |
291 | |
292 | _enter("{%d,%lx},", call->debug_id, call->user_call_ID); | |
293 | ||
294 | cp->peer = rxrpc_lookup_peer(cp->local, srx, gfp); | |
295 | if (!cp->peer) | |
45025bce | 296 | goto error; |
c6d2b8d7 | 297 | |
45025bce DH |
298 | /* If the connection is not meant to be exclusive, search the available |
299 | * connections to see if the connection we want to use already exists. | |
300 | */ | |
c6d2b8d7 | 301 | if (!cp->exclusive) { |
c6d2b8d7 DH |
302 | _debug("search 1"); |
303 | spin_lock(&local->client_conns_lock); | |
304 | p = local->client_conns.rb_node; | |
305 | while (p) { | |
306 | conn = rb_entry(p, struct rxrpc_connection, client_node); | |
307 | ||
308 | #define cmp(X) ((long)conn->params.X - (long)cp->X) | |
309 | diff = (cmp(peer) ?: | |
310 | cmp(key) ?: | |
311 | cmp(security_level)); | |
45025bce DH |
312 | #undef cmp |
313 | if (diff < 0) { | |
c6d2b8d7 | 314 | p = p->rb_left; |
45025bce | 315 | } else if (diff > 0) { |
c6d2b8d7 | 316 | p = p->rb_right; |
45025bce DH |
317 | } else { |
318 | if (rxrpc_may_reuse_conn(conn) && | |
319 | rxrpc_get_connection_maybe(conn)) | |
320 | goto found_extant_conn; | |
321 | /* The connection needs replacing. It's better | |
322 | * to effect that when we have something to | |
323 | * replace it with so that we don't have to | |
324 | * rebalance the tree twice. | |
325 | */ | |
326 | break; | |
327 | } | |
c6d2b8d7 DH |
328 | } |
329 | spin_unlock(&local->client_conns_lock); | |
330 | } | |
331 | ||
45025bce DH |
332 | /* There wasn't a connection yet or we need an exclusive connection. |
333 | * We need to create a candidate and then potentially redo the search | |
334 | * in case we're racing with another thread also trying to connect on a | |
335 | * shareable connection. | |
336 | */ | |
337 | _debug("new conn"); | |
c6d2b8d7 | 338 | candidate = rxrpc_alloc_client_connection(cp, gfp); |
45025bce DH |
339 | if (IS_ERR(candidate)) { |
340 | ret = PTR_ERR(candidate); | |
341 | goto error_peer; | |
c6d2b8d7 DH |
342 | } |
343 | ||
45025bce DH |
344 | /* Add the call to the new connection's waiting list in case we're |
345 | * going to have to wait for the connection to come live. It's our | |
346 | * connection, so we want first dibs on the channel slots. We would | |
347 | * normally have to take channel_lock but we do this before anyone else | |
348 | * can see the connection. | |
349 | */ | |
350 | list_add_tail(&call->chan_wait_link, &candidate->waiting_calls); | |
351 | ||
c6d2b8d7 | 352 | if (cp->exclusive) { |
45025bce | 353 | call->conn = candidate; |
278ac0cd | 354 | call->security_ix = candidate->security_ix; |
45025bce DH |
355 | _leave(" = 0 [exclusive %d]", candidate->debug_id); |
356 | return 0; | |
c6d2b8d7 DH |
357 | } |
358 | ||
45025bce DH |
359 | /* Publish the new connection for userspace to find. We need to redo |
360 | * the search before doing this lest we race with someone else adding a | |
361 | * conflicting instance. | |
c6d2b8d7 DH |
362 | */ |
363 | _debug("search 2"); | |
364 | spin_lock(&local->client_conns_lock); | |
365 | ||
366 | pp = &local->client_conns.rb_node; | |
367 | parent = NULL; | |
368 | while (*pp) { | |
369 | parent = *pp; | |
370 | conn = rb_entry(parent, struct rxrpc_connection, client_node); | |
371 | ||
45025bce | 372 | #define cmp(X) ((long)conn->params.X - (long)candidate->params.X) |
c6d2b8d7 DH |
373 | diff = (cmp(peer) ?: |
374 | cmp(key) ?: | |
375 | cmp(security_level)); | |
45025bce DH |
376 | #undef cmp |
377 | if (diff < 0) { | |
c6d2b8d7 | 378 | pp = &(*pp)->rb_left; |
45025bce | 379 | } else if (diff > 0) { |
c6d2b8d7 | 380 | pp = &(*pp)->rb_right; |
45025bce DH |
381 | } else { |
382 | if (rxrpc_may_reuse_conn(conn) && | |
383 | rxrpc_get_connection_maybe(conn)) | |
384 | goto found_extant_conn; | |
385 | /* The old connection is from an outdated epoch. */ | |
386 | _debug("replace conn"); | |
387 | clear_bit(RXRPC_CONN_IN_CLIENT_CONNS, &conn->flags); | |
388 | rb_replace_node(&conn->client_node, | |
389 | &candidate->client_node, | |
390 | &local->client_conns); | |
363deeab | 391 | trace_rxrpc_client(conn, -1, rxrpc_client_replace); |
45025bce DH |
392 | goto candidate_published; |
393 | } | |
c6d2b8d7 DH |
394 | } |
395 | ||
c6d2b8d7 | 396 | _debug("new conn"); |
001c1122 DH |
397 | rb_link_node(&candidate->client_node, parent, pp); |
398 | rb_insert_color(&candidate->client_node, &local->client_conns); | |
c6d2b8d7 | 399 | |
45025bce DH |
400 | candidate_published: |
401 | set_bit(RXRPC_CONN_IN_CLIENT_CONNS, &candidate->flags); | |
402 | call->conn = candidate; | |
278ac0cd | 403 | call->security_ix = candidate->security_ix; |
c6d2b8d7 | 404 | spin_unlock(&local->client_conns_lock); |
45025bce DH |
405 | _leave(" = 0 [new %d]", candidate->debug_id); |
406 | return 0; | |
c6d2b8d7 | 407 | |
45025bce DH |
408 | /* We come here if we found a suitable connection already in existence. |
409 | * Discard any candidate we may have allocated, and try to get a | |
410 | * channel on this one. | |
411 | */ | |
412 | found_extant_conn: | |
413 | _debug("found conn"); | |
414 | spin_unlock(&local->client_conns_lock); | |
c6d2b8d7 | 415 | |
363deeab DH |
416 | if (candidate) { |
417 | trace_rxrpc_client(candidate, -1, rxrpc_client_duplicate); | |
418 | rxrpc_put_connection(candidate); | |
419 | candidate = NULL; | |
420 | } | |
c6d2b8d7 | 421 | |
45025bce DH |
422 | spin_lock(&conn->channel_lock); |
423 | call->conn = conn; | |
278ac0cd | 424 | call->security_ix = conn->security_ix; |
45025bce | 425 | list_add(&call->chan_wait_link, &conn->waiting_calls); |
c6d2b8d7 | 426 | spin_unlock(&conn->channel_lock); |
45025bce DH |
427 | _leave(" = 0 [extant %d]", conn->debug_id); |
428 | return 0; | |
429 | ||
430 | error_peer: | |
c6d2b8d7 DH |
431 | rxrpc_put_peer(cp->peer); |
432 | cp->peer = NULL; | |
45025bce DH |
433 | error: |
434 | _leave(" = %d", ret); | |
435 | return ret; | |
436 | } | |
c6d2b8d7 | 437 | |
45025bce DH |
438 | /* |
439 | * Activate a connection. | |
440 | */ | |
441 | static void rxrpc_activate_conn(struct rxrpc_connection *conn) | |
442 | { | |
363deeab | 443 | trace_rxrpc_client(conn, -1, rxrpc_client_to_active); |
45025bce DH |
444 | conn->cache_state = RXRPC_CONN_CLIENT_ACTIVE; |
445 | rxrpc_nr_active_client_conns++; | |
446 | list_move_tail(&conn->cache_link, &rxrpc_active_client_conns); | |
447 | } | |
448 | ||
449 | /* | |
450 | * Attempt to animate a connection for a new call. | |
451 | * | |
452 | * If it's not exclusive, the connection is in the endpoint tree, and we're in | |
453 | * the conn's list of those waiting to grab a channel. There is, however, a | |
454 | * limit on the number of live connections allowed at any one time, so we may | |
455 | * have to wait for capacity to become available. | |
456 | * | |
457 | * Note that a connection on the waiting queue might *also* have active | |
458 | * channels if it has been culled to make space and then re-requested by a new | |
459 | * call. | |
460 | */ | |
461 | static void rxrpc_animate_client_conn(struct rxrpc_connection *conn) | |
462 | { | |
463 | unsigned int nr_conns; | |
464 | ||
465 | _enter("%d,%d", conn->debug_id, conn->cache_state); | |
466 | ||
467 | if (conn->cache_state == RXRPC_CONN_CLIENT_ACTIVE) | |
468 | goto out; | |
469 | ||
470 | spin_lock(&rxrpc_client_conn_cache_lock); | |
471 | ||
472 | nr_conns = rxrpc_nr_client_conns; | |
363deeab DH |
473 | if (!test_and_set_bit(RXRPC_CONN_COUNTED, &conn->flags)) { |
474 | trace_rxrpc_client(conn, -1, rxrpc_client_count); | |
45025bce | 475 | rxrpc_nr_client_conns = nr_conns + 1; |
363deeab | 476 | } |
45025bce DH |
477 | |
478 | switch (conn->cache_state) { | |
479 | case RXRPC_CONN_CLIENT_ACTIVE: | |
480 | case RXRPC_CONN_CLIENT_WAITING: | |
481 | break; | |
482 | ||
483 | case RXRPC_CONN_CLIENT_INACTIVE: | |
484 | case RXRPC_CONN_CLIENT_CULLED: | |
485 | case RXRPC_CONN_CLIENT_IDLE: | |
486 | if (nr_conns >= rxrpc_max_client_connections) | |
487 | goto wait_for_capacity; | |
488 | goto activate_conn; | |
489 | ||
490 | default: | |
491 | BUG(); | |
001c1122 DH |
492 | } |
493 | ||
45025bce DH |
494 | out_unlock: |
495 | spin_unlock(&rxrpc_client_conn_cache_lock); | |
496 | out: | |
497 | _leave(" [%d]", conn->cache_state); | |
498 | return; | |
c6d2b8d7 | 499 | |
45025bce DH |
500 | activate_conn: |
501 | _debug("activate"); | |
502 | rxrpc_activate_conn(conn); | |
503 | goto out_unlock; | |
504 | ||
505 | wait_for_capacity: | |
506 | _debug("wait"); | |
363deeab | 507 | trace_rxrpc_client(conn, -1, rxrpc_client_to_waiting); |
45025bce DH |
508 | conn->cache_state = RXRPC_CONN_CLIENT_WAITING; |
509 | list_move_tail(&conn->cache_link, &rxrpc_waiting_client_conns); | |
510 | goto out_unlock; | |
511 | } | |
512 | ||
513 | /* | |
514 | * Deactivate a channel. | |
515 | */ | |
516 | static void rxrpc_deactivate_one_channel(struct rxrpc_connection *conn, | |
517 | unsigned int channel) | |
518 | { | |
519 | struct rxrpc_channel *chan = &conn->channels[channel]; | |
520 | ||
521 | rcu_assign_pointer(chan->call, NULL); | |
522 | conn->active_chans &= ~(1 << channel); | |
523 | } | |
524 | ||
525 | /* | |
526 | * Assign a channel to the call at the front of the queue and wake the call up. | |
527 | * We don't increment the callNumber counter until this number has been exposed | |
528 | * to the world. | |
529 | */ | |
530 | static void rxrpc_activate_one_channel(struct rxrpc_connection *conn, | |
531 | unsigned int channel) | |
532 | { | |
533 | struct rxrpc_channel *chan = &conn->channels[channel]; | |
534 | struct rxrpc_call *call = list_entry(conn->waiting_calls.next, | |
535 | struct rxrpc_call, chan_wait_link); | |
536 | u32 call_id = chan->call_counter + 1; | |
537 | ||
363deeab DH |
538 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_activate); |
539 | ||
af338a9e DH |
540 | write_lock_bh(&call->state_lock); |
541 | call->state = RXRPC_CALL_CLIENT_SEND_REQUEST; | |
542 | write_unlock_bh(&call->state_lock); | |
543 | ||
e34d4234 | 544 | rxrpc_see_call(call); |
45025bce DH |
545 | list_del_init(&call->chan_wait_link); |
546 | conn->active_chans |= 1 << channel; | |
547 | call->peer = rxrpc_get_peer(conn->params.peer); | |
548 | call->cid = conn->proto.cid | channel; | |
549 | call->call_id = call_id; | |
550 | ||
551 | _net("CONNECT call %08x:%08x as call %d on conn %d", | |
552 | call->cid, call->call_id, call->debug_id, conn->debug_id); | |
553 | ||
554 | /* Paired with the read barrier in rxrpc_wait_for_channel(). This | |
555 | * orders cid and epoch in the connection wrt to call_id without the | |
556 | * need to take the channel_lock. | |
557 | * | |
558 | * We provisionally assign a callNumber at this point, but we don't | |
559 | * confirm it until the call is about to be exposed. | |
560 | * | |
561 | * TODO: Pair with a barrier in the data_ready handler when that looks | |
562 | * at the call ID through a connection channel. | |
563 | */ | |
564 | smp_wmb(); | |
565 | chan->call_id = call_id; | |
566 | rcu_assign_pointer(chan->call, call); | |
567 | wake_up(&call->waitq); | |
568 | } | |
569 | ||
2629c7fa DH |
570 | /* |
571 | * Assign channels and callNumbers to waiting calls with channel_lock | |
572 | * held by caller. | |
573 | */ | |
574 | static void rxrpc_activate_channels_locked(struct rxrpc_connection *conn) | |
575 | { | |
576 | u8 avail, mask; | |
577 | ||
578 | switch (conn->cache_state) { | |
579 | case RXRPC_CONN_CLIENT_ACTIVE: | |
580 | mask = RXRPC_ACTIVE_CHANS_MASK; | |
581 | break; | |
582 | default: | |
583 | return; | |
584 | } | |
585 | ||
586 | while (!list_empty(&conn->waiting_calls) && | |
587 | (avail = ~conn->active_chans, | |
588 | avail &= mask, | |
589 | avail != 0)) | |
590 | rxrpc_activate_one_channel(conn, __ffs(avail)); | |
591 | } | |
592 | ||
45025bce DH |
593 | /* |
594 | * Assign channels and callNumbers to waiting calls. | |
595 | */ | |
596 | static void rxrpc_activate_channels(struct rxrpc_connection *conn) | |
597 | { | |
45025bce DH |
598 | _enter("%d", conn->debug_id); |
599 | ||
363deeab DH |
600 | trace_rxrpc_client(conn, -1, rxrpc_client_activate_chans); |
601 | ||
2629c7fa | 602 | if (conn->active_chans == RXRPC_ACTIVE_CHANS_MASK) |
45025bce DH |
603 | return; |
604 | ||
605 | spin_lock(&conn->channel_lock); | |
2629c7fa | 606 | rxrpc_activate_channels_locked(conn); |
45025bce DH |
607 | spin_unlock(&conn->channel_lock); |
608 | _leave(""); | |
609 | } | |
610 | ||
611 | /* | |
612 | * Wait for a callNumber and a channel to be granted to a call. | |
613 | */ | |
614 | static int rxrpc_wait_for_channel(struct rxrpc_call *call, gfp_t gfp) | |
615 | { | |
616 | int ret = 0; | |
617 | ||
618 | _enter("%d", call->debug_id); | |
619 | ||
620 | if (!call->call_id) { | |
621 | DECLARE_WAITQUEUE(myself, current); | |
c6d2b8d7 | 622 | |
c6d2b8d7 | 623 | if (!gfpflags_allow_blocking(gfp)) { |
45025bce DH |
624 | ret = -EAGAIN; |
625 | goto out; | |
c6d2b8d7 DH |
626 | } |
627 | ||
45025bce | 628 | add_wait_queue_exclusive(&call->waitq, &myself); |
c6d2b8d7 DH |
629 | for (;;) { |
630 | set_current_state(TASK_INTERRUPTIBLE); | |
45025bce DH |
631 | if (call->call_id) |
632 | break; | |
633 | if (signal_pending(current)) { | |
634 | ret = -ERESTARTSYS; | |
c6d2b8d7 | 635 | break; |
45025bce | 636 | } |
c6d2b8d7 DH |
637 | schedule(); |
638 | } | |
45025bce | 639 | remove_wait_queue(&call->waitq, &myself); |
c6d2b8d7 DH |
640 | __set_current_state(TASK_RUNNING); |
641 | } | |
642 | ||
45025bce DH |
643 | /* Paired with the write barrier in rxrpc_activate_one_channel(). */ |
644 | smp_rmb(); | |
645 | ||
646 | out: | |
647 | _leave(" = %d", ret); | |
648 | return ret; | |
649 | } | |
650 | ||
651 | /* | |
652 | * find a connection for a call | |
653 | * - called in process context with IRQs enabled | |
654 | */ | |
655 | int rxrpc_connect_call(struct rxrpc_call *call, | |
656 | struct rxrpc_conn_parameters *cp, | |
657 | struct sockaddr_rxrpc *srx, | |
658 | gfp_t gfp) | |
659 | { | |
660 | int ret; | |
661 | ||
662 | _enter("{%d,%lx},", call->debug_id, call->user_call_ID); | |
663 | ||
664 | rxrpc_discard_expired_client_conns(NULL); | |
665 | rxrpc_cull_active_client_conns(); | |
666 | ||
667 | ret = rxrpc_get_client_conn(call, cp, srx, gfp); | |
668 | if (ret < 0) | |
669 | return ret; | |
670 | ||
671 | rxrpc_animate_client_conn(call->conn); | |
672 | rxrpc_activate_channels(call->conn); | |
673 | ||
674 | ret = rxrpc_wait_for_channel(call, gfp); | |
675 | if (ret < 0) | |
676 | rxrpc_disconnect_client_call(call); | |
677 | ||
678 | _leave(" = %d", ret); | |
679 | return ret; | |
680 | } | |
681 | ||
682 | /* | |
683 | * Note that a connection is about to be exposed to the world. Once it is | |
684 | * exposed, we maintain an extra ref on it that stops it from being summarily | |
685 | * discarded before it's (a) had a chance to deal with retransmission and (b) | |
686 | * had a chance at re-use (the per-connection security negotiation is | |
687 | * expensive). | |
688 | */ | |
363deeab DH |
689 | static void rxrpc_expose_client_conn(struct rxrpc_connection *conn, |
690 | unsigned int channel) | |
45025bce | 691 | { |
363deeab DH |
692 | if (!test_and_set_bit(RXRPC_CONN_EXPOSED, &conn->flags)) { |
693 | trace_rxrpc_client(conn, channel, rxrpc_client_exposed); | |
45025bce | 694 | rxrpc_get_connection(conn); |
363deeab | 695 | } |
45025bce DH |
696 | } |
697 | ||
698 | /* | |
699 | * Note that a call, and thus a connection, is about to be exposed to the | |
700 | * world. | |
701 | */ | |
702 | void rxrpc_expose_client_call(struct rxrpc_call *call) | |
703 | { | |
363deeab | 704 | unsigned int channel = call->cid & RXRPC_CHANNELMASK; |
45025bce | 705 | struct rxrpc_connection *conn = call->conn; |
363deeab | 706 | struct rxrpc_channel *chan = &conn->channels[channel]; |
45025bce DH |
707 | |
708 | if (!test_and_set_bit(RXRPC_CALL_EXPOSED, &call->flags)) { | |
709 | /* Mark the call ID as being used. If the callNumber counter | |
710 | * exceeds ~2 billion, we kill the connection after its | |
711 | * outstanding calls have finished so that the counter doesn't | |
712 | * wrap. | |
713 | */ | |
714 | chan->call_counter++; | |
715 | if (chan->call_counter >= INT_MAX) | |
716 | set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags); | |
363deeab | 717 | rxrpc_expose_client_conn(conn, channel); |
45025bce DH |
718 | } |
719 | } | |
720 | ||
721 | /* | |
722 | * Disconnect a client call. | |
723 | */ | |
724 | void rxrpc_disconnect_client_call(struct rxrpc_call *call) | |
725 | { | |
726 | unsigned int channel = call->cid & RXRPC_CHANNELMASK; | |
727 | struct rxrpc_connection *conn = call->conn; | |
728 | struct rxrpc_channel *chan = &conn->channels[channel]; | |
729 | ||
363deeab | 730 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_disconnect); |
45025bce DH |
731 | call->conn = NULL; |
732 | ||
c6d2b8d7 DH |
733 | spin_lock(&conn->channel_lock); |
734 | ||
45025bce DH |
735 | /* Calls that have never actually been assigned a channel can simply be |
736 | * discarded. If the conn didn't get used either, it will follow | |
737 | * immediately unless someone else grabs it in the meantime. | |
738 | */ | |
739 | if (!list_empty(&call->chan_wait_link)) { | |
740 | _debug("call is waiting"); | |
741 | ASSERTCMP(call->call_id, ==, 0); | |
742 | ASSERT(!test_bit(RXRPC_CALL_EXPOSED, &call->flags)); | |
743 | list_del_init(&call->chan_wait_link); | |
744 | ||
363deeab DH |
745 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_unstarted); |
746 | ||
45025bce DH |
747 | /* We must deactivate or idle the connection if it's now |
748 | * waiting for nothing. | |
749 | */ | |
750 | spin_lock(&rxrpc_client_conn_cache_lock); | |
751 | if (conn->cache_state == RXRPC_CONN_CLIENT_WAITING && | |
752 | list_empty(&conn->waiting_calls) && | |
753 | !conn->active_chans) | |
754 | goto idle_connection; | |
755 | goto out; | |
756 | } | |
757 | ||
758 | ASSERTCMP(rcu_access_pointer(chan->call), ==, call); | |
45025bce DH |
759 | |
760 | /* If a client call was exposed to the world, we save the result for | |
761 | * retransmission. | |
762 | * | |
763 | * We use a barrier here so that the call number and abort code can be | |
764 | * read without needing to take a lock. | |
765 | * | |
766 | * TODO: Make the incoming packet handler check this and handle | |
767 | * terminal retransmission without requiring access to the call. | |
768 | */ | |
769 | if (test_bit(RXRPC_CALL_EXPOSED, &call->flags)) { | |
f5c17aae | 770 | _debug("exposed %u,%u", call->call_id, call->abort_code); |
45025bce DH |
771 | __rxrpc_disconnect_call(conn, call); |
772 | } | |
773 | ||
774 | /* See if we can pass the channel directly to another call. */ | |
775 | if (conn->cache_state == RXRPC_CONN_CLIENT_ACTIVE && | |
776 | !list_empty(&conn->waiting_calls)) { | |
363deeab | 777 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass); |
45025bce DH |
778 | rxrpc_activate_one_channel(conn, channel); |
779 | goto out_2; | |
780 | } | |
781 | ||
782 | /* Things are more complex and we need the cache lock. We might be | |
783 | * able to simply idle the conn or it might now be lurking on the wait | |
784 | * list. It might even get moved back to the active list whilst we're | |
785 | * waiting for the lock. | |
786 | */ | |
787 | spin_lock(&rxrpc_client_conn_cache_lock); | |
788 | ||
789 | switch (conn->cache_state) { | |
790 | case RXRPC_CONN_CLIENT_ACTIVE: | |
791 | if (list_empty(&conn->waiting_calls)) { | |
792 | rxrpc_deactivate_one_channel(conn, channel); | |
793 | if (!conn->active_chans) { | |
794 | rxrpc_nr_active_client_conns--; | |
795 | goto idle_connection; | |
796 | } | |
797 | goto out; | |
798 | } | |
799 | ||
363deeab | 800 | trace_rxrpc_client(conn, channel, rxrpc_client_chan_pass); |
45025bce DH |
801 | rxrpc_activate_one_channel(conn, channel); |
802 | goto out; | |
803 | ||
804 | case RXRPC_CONN_CLIENT_CULLED: | |
805 | rxrpc_deactivate_one_channel(conn, channel); | |
806 | ASSERT(list_empty(&conn->waiting_calls)); | |
807 | if (!conn->active_chans) | |
808 | goto idle_connection; | |
809 | goto out; | |
810 | ||
811 | case RXRPC_CONN_CLIENT_WAITING: | |
812 | rxrpc_deactivate_one_channel(conn, channel); | |
813 | goto out; | |
814 | ||
815 | default: | |
816 | BUG(); | |
817 | } | |
c6d2b8d7 | 818 | |
45025bce DH |
819 | out: |
820 | spin_unlock(&rxrpc_client_conn_cache_lock); | |
821 | out_2: | |
822 | spin_unlock(&conn->channel_lock); | |
c6d2b8d7 | 823 | rxrpc_put_connection(conn); |
45025bce DH |
824 | _leave(""); |
825 | return; | |
826 | ||
827 | idle_connection: | |
828 | /* As no channels remain active, the connection gets deactivated | |
829 | * immediately or moved to the idle list for a short while. | |
830 | */ | |
831 | if (test_bit(RXRPC_CONN_EXPOSED, &conn->flags)) { | |
363deeab | 832 | trace_rxrpc_client(conn, channel, rxrpc_client_to_idle); |
45025bce DH |
833 | conn->idle_timestamp = jiffies; |
834 | conn->cache_state = RXRPC_CONN_CLIENT_IDLE; | |
835 | list_move_tail(&conn->cache_link, &rxrpc_idle_client_conns); | |
836 | if (rxrpc_idle_client_conns.next == &conn->cache_link && | |
837 | !rxrpc_kill_all_client_conns) | |
838 | queue_delayed_work(rxrpc_workqueue, | |
839 | &rxrpc_client_conn_reap, | |
840 | rxrpc_conn_idle_client_expiry); | |
841 | } else { | |
363deeab | 842 | trace_rxrpc_client(conn, channel, rxrpc_client_to_inactive); |
45025bce DH |
843 | conn->cache_state = RXRPC_CONN_CLIENT_INACTIVE; |
844 | list_del_init(&conn->cache_link); | |
845 | } | |
846 | goto out; | |
c6d2b8d7 | 847 | } |
001c1122 DH |
848 | |
849 | /* | |
45025bce | 850 | * Clean up a dead client connection. |
001c1122 | 851 | */ |
45025bce DH |
852 | static struct rxrpc_connection * |
853 | rxrpc_put_one_client_conn(struct rxrpc_connection *conn) | |
001c1122 | 854 | { |
66d58af7 | 855 | struct rxrpc_connection *next = NULL; |
001c1122 | 856 | struct rxrpc_local *local = conn->params.local; |
45025bce | 857 | unsigned int nr_conns; |
001c1122 | 858 | |
363deeab DH |
859 | trace_rxrpc_client(conn, -1, rxrpc_client_cleanup); |
860 | ||
45025bce DH |
861 | if (test_bit(RXRPC_CONN_IN_CLIENT_CONNS, &conn->flags)) { |
862 | spin_lock(&local->client_conns_lock); | |
863 | if (test_and_clear_bit(RXRPC_CONN_IN_CLIENT_CONNS, | |
864 | &conn->flags)) | |
865 | rb_erase(&conn->client_node, &local->client_conns); | |
866 | spin_unlock(&local->client_conns_lock); | |
867 | } | |
001c1122 DH |
868 | |
869 | rxrpc_put_client_connection_id(conn); | |
45025bce DH |
870 | |
871 | ASSERTCMP(conn->cache_state, ==, RXRPC_CONN_CLIENT_INACTIVE); | |
872 | ||
66d58af7 | 873 | if (test_bit(RXRPC_CONN_COUNTED, &conn->flags)) { |
363deeab | 874 | trace_rxrpc_client(conn, -1, rxrpc_client_uncount); |
66d58af7 DH |
875 | spin_lock(&rxrpc_client_conn_cache_lock); |
876 | nr_conns = --rxrpc_nr_client_conns; | |
877 | ||
878 | if (nr_conns < rxrpc_max_client_connections && | |
879 | !list_empty(&rxrpc_waiting_client_conns)) { | |
880 | next = list_entry(rxrpc_waiting_client_conns.next, | |
881 | struct rxrpc_connection, cache_link); | |
882 | rxrpc_get_connection(next); | |
883 | rxrpc_activate_conn(next); | |
884 | } | |
45025bce | 885 | |
66d58af7 | 886 | spin_unlock(&rxrpc_client_conn_cache_lock); |
45025bce DH |
887 | } |
888 | ||
45025bce | 889 | rxrpc_kill_connection(conn); |
45025bce DH |
890 | if (next) |
891 | rxrpc_activate_channels(next); | |
892 | ||
893 | /* We need to get rid of the temporary ref we took upon next, but we | |
894 | * can't call rxrpc_put_connection() recursively. | |
895 | */ | |
896 | return next; | |
897 | } | |
898 | ||
899 | /* | |
900 | * Clean up a dead client connections. | |
901 | */ | |
902 | void rxrpc_put_client_conn(struct rxrpc_connection *conn) | |
903 | { | |
363deeab DH |
904 | const void *here = __builtin_return_address(0); |
905 | int n; | |
45025bce DH |
906 | |
907 | do { | |
363deeab DH |
908 | n = atomic_dec_return(&conn->usage); |
909 | trace_rxrpc_conn(conn, rxrpc_conn_put_client, n, here); | |
910 | if (n > 0) | |
911 | return; | |
912 | ASSERTCMP(n, >=, 0); | |
913 | ||
914 | conn = rxrpc_put_one_client_conn(conn); | |
915 | } while (conn); | |
45025bce DH |
916 | } |
917 | ||
918 | /* | |
919 | * Kill the longest-active client connections to make room for new ones. | |
920 | */ | |
921 | static void rxrpc_cull_active_client_conns(void) | |
922 | { | |
923 | struct rxrpc_connection *conn; | |
924 | unsigned int nr_conns = rxrpc_nr_client_conns; | |
925 | unsigned int nr_active, limit; | |
926 | ||
927 | _enter(""); | |
928 | ||
929 | ASSERTCMP(nr_conns, >=, 0); | |
930 | if (nr_conns < rxrpc_max_client_connections) { | |
931 | _leave(" [ok]"); | |
932 | return; | |
933 | } | |
934 | limit = rxrpc_reap_client_connections; | |
935 | ||
936 | spin_lock(&rxrpc_client_conn_cache_lock); | |
937 | nr_active = rxrpc_nr_active_client_conns; | |
938 | ||
939 | while (nr_active > limit) { | |
940 | ASSERT(!list_empty(&rxrpc_active_client_conns)); | |
941 | conn = list_entry(rxrpc_active_client_conns.next, | |
942 | struct rxrpc_connection, cache_link); | |
943 | ASSERTCMP(conn->cache_state, ==, RXRPC_CONN_CLIENT_ACTIVE); | |
944 | ||
945 | if (list_empty(&conn->waiting_calls)) { | |
363deeab | 946 | trace_rxrpc_client(conn, -1, rxrpc_client_to_culled); |
45025bce DH |
947 | conn->cache_state = RXRPC_CONN_CLIENT_CULLED; |
948 | list_del_init(&conn->cache_link); | |
949 | } else { | |
363deeab | 950 | trace_rxrpc_client(conn, -1, rxrpc_client_to_waiting); |
45025bce DH |
951 | conn->cache_state = RXRPC_CONN_CLIENT_WAITING; |
952 | list_move_tail(&conn->cache_link, | |
953 | &rxrpc_waiting_client_conns); | |
954 | } | |
955 | ||
956 | nr_active--; | |
957 | } | |
958 | ||
959 | rxrpc_nr_active_client_conns = nr_active; | |
960 | spin_unlock(&rxrpc_client_conn_cache_lock); | |
961 | ASSERTCMP(nr_active, >=, 0); | |
962 | _leave(" [culled]"); | |
963 | } | |
964 | ||
965 | /* | |
966 | * Discard expired client connections from the idle list. Each conn in the | |
967 | * idle list has been exposed and holds an extra ref because of that. | |
968 | * | |
969 | * This may be called from conn setup or from a work item so cannot be | |
970 | * considered non-reentrant. | |
971 | */ | |
972 | static void rxrpc_discard_expired_client_conns(struct work_struct *work) | |
973 | { | |
974 | struct rxrpc_connection *conn; | |
975 | unsigned long expiry, conn_expires_at, now; | |
976 | unsigned int nr_conns; | |
977 | bool did_discard = false; | |
978 | ||
979 | _enter("%c", work ? 'w' : 'n'); | |
980 | ||
981 | if (list_empty(&rxrpc_idle_client_conns)) { | |
982 | _leave(" [empty]"); | |
983 | return; | |
984 | } | |
985 | ||
986 | /* Don't double up on the discarding */ | |
987 | if (!spin_trylock(&rxrpc_client_conn_discard_mutex)) { | |
988 | _leave(" [already]"); | |
989 | return; | |
990 | } | |
991 | ||
992 | /* We keep an estimate of what the number of conns ought to be after | |
993 | * we've discarded some so that we don't overdo the discarding. | |
994 | */ | |
995 | nr_conns = rxrpc_nr_client_conns; | |
996 | ||
997 | next: | |
998 | spin_lock(&rxrpc_client_conn_cache_lock); | |
999 | ||
1000 | if (list_empty(&rxrpc_idle_client_conns)) | |
1001 | goto out; | |
1002 | ||
1003 | conn = list_entry(rxrpc_idle_client_conns.next, | |
1004 | struct rxrpc_connection, cache_link); | |
1005 | ASSERT(test_bit(RXRPC_CONN_EXPOSED, &conn->flags)); | |
1006 | ||
1007 | if (!rxrpc_kill_all_client_conns) { | |
1008 | /* If the number of connections is over the reap limit, we | |
1009 | * expedite discard by reducing the expiry timeout. We must, | |
1010 | * however, have at least a short grace period to be able to do | |
1011 | * final-ACK or ABORT retransmission. | |
1012 | */ | |
1013 | expiry = rxrpc_conn_idle_client_expiry; | |
1014 | if (nr_conns > rxrpc_reap_client_connections) | |
1015 | expiry = rxrpc_conn_idle_client_fast_expiry; | |
1016 | ||
1017 | conn_expires_at = conn->idle_timestamp + expiry; | |
1018 | ||
1019 | now = READ_ONCE(jiffies); | |
1020 | if (time_after(conn_expires_at, now)) | |
1021 | goto not_yet_expired; | |
1022 | } | |
1023 | ||
363deeab | 1024 | trace_rxrpc_client(conn, -1, rxrpc_client_discard); |
45025bce DH |
1025 | if (!test_and_clear_bit(RXRPC_CONN_EXPOSED, &conn->flags)) |
1026 | BUG(); | |
1027 | conn->cache_state = RXRPC_CONN_CLIENT_INACTIVE; | |
1028 | list_del_init(&conn->cache_link); | |
1029 | ||
1030 | spin_unlock(&rxrpc_client_conn_cache_lock); | |
1031 | ||
1032 | /* When we cleared the EXPOSED flag, we took on responsibility for the | |
1033 | * reference that that had on the usage count. We deal with that here. | |
1034 | * If someone re-sets the flag and re-gets the ref, that's fine. | |
1035 | */ | |
1036 | rxrpc_put_connection(conn); | |
1037 | did_discard = true; | |
1038 | nr_conns--; | |
1039 | goto next; | |
1040 | ||
1041 | not_yet_expired: | |
1042 | /* The connection at the front of the queue hasn't yet expired, so | |
1043 | * schedule the work item for that point if we discarded something. | |
1044 | * | |
1045 | * We don't worry if the work item is already scheduled - it can look | |
1046 | * after rescheduling itself at a later time. We could cancel it, but | |
1047 | * then things get messier. | |
1048 | */ | |
1049 | _debug("not yet"); | |
1050 | if (!rxrpc_kill_all_client_conns) | |
1051 | queue_delayed_work(rxrpc_workqueue, | |
1052 | &rxrpc_client_conn_reap, | |
1053 | conn_expires_at - now); | |
1054 | ||
1055 | out: | |
1056 | spin_unlock(&rxrpc_client_conn_cache_lock); | |
1057 | spin_unlock(&rxrpc_client_conn_discard_mutex); | |
1058 | _leave(""); | |
1059 | } | |
1060 | ||
1061 | /* | |
1062 | * Preemptively destroy all the client connection records rather than waiting | |
1063 | * for them to time out | |
1064 | */ | |
1065 | void __exit rxrpc_destroy_all_client_connections(void) | |
1066 | { | |
1067 | _enter(""); | |
1068 | ||
1069 | spin_lock(&rxrpc_client_conn_cache_lock); | |
1070 | rxrpc_kill_all_client_conns = true; | |
1071 | spin_unlock(&rxrpc_client_conn_cache_lock); | |
1072 | ||
1073 | cancel_delayed_work(&rxrpc_client_conn_reap); | |
1074 | ||
1075 | if (!queue_delayed_work(rxrpc_workqueue, &rxrpc_client_conn_reap, 0)) | |
1076 | _debug("destroy: queue failed"); | |
1077 | ||
1078 | _leave(""); | |
001c1122 | 1079 | } |