Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
ec26815a | 2 | /* AFS cell and server record management |
1da177e4 | 3 | * |
989782dc | 4 | * Copyright (C) 2002, 2017 Red Hat, Inc. All Rights Reserved. |
1da177e4 | 5 | * Written by David Howells (dhowells@redhat.com) |
1da177e4 LT |
6 | */ |
7 | ||
1da177e4 | 8 | #include <linux/slab.h> |
00d3b7a4 DH |
9 | #include <linux/key.h> |
10 | #include <linux/ctype.h> | |
07567a55 | 11 | #include <linux/dns_resolver.h> |
e8edc6e0 | 12 | #include <linux/sched.h> |
3838d3ec | 13 | #include <linux/inet.h> |
0da0b7fd | 14 | #include <linux/namei.h> |
00d3b7a4 | 15 | #include <keys/rxrpc-type.h> |
1da177e4 LT |
16 | #include "internal.h" |
17 | ||
fe342cf7 | 18 | static unsigned __read_mostly afs_cell_gc_delay = 10; |
ded2f4c5 DH |
19 | static unsigned __read_mostly afs_cell_min_ttl = 10 * 60; |
20 | static unsigned __read_mostly afs_cell_max_ttl = 24 * 60 * 60; | |
989782dc DH |
21 | |
22 | static void afs_manage_cell(struct work_struct *); | |
23 | ||
24 | static void afs_dec_cells_outstanding(struct afs_net *net) | |
25 | { | |
26 | if (atomic_dec_and_test(&net->cells_outstanding)) | |
ab1fbe32 | 27 | wake_up_var(&net->cells_outstanding); |
989782dc DH |
28 | } |
29 | ||
1da177e4 | 30 | /* |
989782dc DH |
31 | * Set the cell timer to fire after a given delay, assuming it's not already |
32 | * set for an earlier time. | |
1da177e4 | 33 | */ |
989782dc | 34 | static void afs_set_cell_timer(struct afs_net *net, time64_t delay) |
1da177e4 | 35 | { |
989782dc DH |
36 | if (net->live) { |
37 | atomic_inc(&net->cells_outstanding); | |
38 | if (timer_reduce(&net->cells_timer, jiffies + delay * HZ)) | |
39 | afs_dec_cells_outstanding(net); | |
40 | } | |
41 | } | |
42 | ||
43 | /* | |
44 | * Look up and get an activation reference on a cell record under RCU | |
45 | * conditions. The caller must hold the RCU read lock. | |
46 | */ | |
47 | struct afs_cell *afs_lookup_cell_rcu(struct afs_net *net, | |
48 | const char *name, unsigned int namesz) | |
49 | { | |
50 | struct afs_cell *cell = NULL; | |
51 | struct rb_node *p; | |
52 | int n, seq = 0, ret = 0; | |
53 | ||
54 | _enter("%*.*s", namesz, namesz, name); | |
55 | ||
56 | if (name && namesz == 0) | |
57 | return ERR_PTR(-EINVAL); | |
58 | if (namesz > AFS_MAXCELLNAME) | |
59 | return ERR_PTR(-ENAMETOOLONG); | |
60 | ||
61 | do { | |
62 | /* Unfortunately, rbtree walking doesn't give reliable results | |
63 | * under just the RCU read lock, so we have to check for | |
64 | * changes. | |
65 | */ | |
66 | if (cell) | |
67 | afs_put_cell(net, cell); | |
68 | cell = NULL; | |
69 | ret = -ENOENT; | |
70 | ||
71 | read_seqbegin_or_lock(&net->cells_lock, &seq); | |
72 | ||
73 | if (!name) { | |
74 | cell = rcu_dereference_raw(net->ws_cell); | |
75 | if (cell) { | |
76 | afs_get_cell(cell); | |
fe342cf7 | 77 | break; |
989782dc DH |
78 | } |
79 | ret = -EDESTADDRREQ; | |
80 | continue; | |
81 | } | |
82 | ||
83 | p = rcu_dereference_raw(net->cells.rb_node); | |
84 | while (p) { | |
85 | cell = rb_entry(p, struct afs_cell, net_node); | |
86 | ||
87 | n = strncasecmp(cell->name, name, | |
88 | min_t(size_t, cell->name_len, namesz)); | |
89 | if (n == 0) | |
90 | n = cell->name_len - namesz; | |
91 | if (n < 0) { | |
92 | p = rcu_dereference_raw(p->rb_left); | |
93 | } else if (n > 0) { | |
94 | p = rcu_dereference_raw(p->rb_right); | |
95 | } else { | |
96 | if (atomic_inc_not_zero(&cell->usage)) { | |
97 | ret = 0; | |
98 | break; | |
99 | } | |
100 | /* We want to repeat the search, this time with | |
101 | * the lock properly locked. | |
102 | */ | |
103 | } | |
104 | cell = NULL; | |
105 | } | |
1da177e4 | 106 | |
989782dc | 107 | } while (need_seqretry(&net->cells_lock, seq)); |
1da177e4 | 108 | |
989782dc | 109 | done_seqretry(&net->cells_lock, seq); |
1da177e4 | 110 | |
989782dc DH |
111 | return ret == 0 ? cell : ERR_PTR(ret); |
112 | } | |
113 | ||
114 | /* | |
115 | * Set up a cell record and fill in its name, VL server address list and | |
116 | * allocate an anonymous key | |
117 | */ | |
118 | static struct afs_cell *afs_alloc_cell(struct afs_net *net, | |
119 | const char *name, unsigned int namelen, | |
0a5143f2 | 120 | const char *addresses) |
989782dc | 121 | { |
ca1cbbdc | 122 | struct afs_vlserver_list *vllist; |
989782dc DH |
123 | struct afs_cell *cell; |
124 | int i, ret; | |
125 | ||
126 | ASSERT(name); | |
127 | if (namelen == 0) | |
128 | return ERR_PTR(-EINVAL); | |
07567a55 WL |
129 | if (namelen > AFS_MAXCELLNAME) { |
130 | _leave(" = -ENAMETOOLONG"); | |
00d3b7a4 | 131 | return ERR_PTR(-ENAMETOOLONG); |
07567a55 | 132 | } |
37ab6368 DH |
133 | if (namelen == 5 && memcmp(name, "@cell", 5) == 0) |
134 | return ERR_PTR(-EINVAL); | |
00d3b7a4 | 135 | |
0a5143f2 | 136 | _enter("%*.*s,%s", namelen, namelen, name, addresses); |
989782dc DH |
137 | |
138 | cell = kzalloc(sizeof(struct afs_cell), GFP_KERNEL); | |
1da177e4 LT |
139 | if (!cell) { |
140 | _leave(" = -ENOMEM"); | |
08e0e7c8 | 141 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
142 | } |
143 | ||
f044c884 | 144 | cell->net = net; |
989782dc DH |
145 | cell->name_len = namelen; |
146 | for (i = 0; i < namelen; i++) | |
147 | cell->name[i] = tolower(name[i]); | |
148 | ||
149 | atomic_set(&cell->usage, 2); | |
150 | INIT_WORK(&cell->manager, afs_manage_cell); | |
d2ddc776 DH |
151 | INIT_LIST_HEAD(&cell->proc_volumes); |
152 | rwlock_init(&cell->proc_lock); | |
0a5143f2 | 153 | rwlock_init(&cell->vl_servers_lock); |
4d9df986 | 154 | |
ca1cbbdc DH |
155 | /* Provide a VL server list, filling it in if we were given a list of |
156 | * addresses to use. | |
989782dc | 157 | */ |
0a5143f2 | 158 | if (addresses) { |
0a5143f2 DH |
159 | vllist = afs_parse_text_addrs(net, |
160 | addresses, strlen(addresses), ':', | |
161 | VL_SERVICE, AFS_VL_PORT); | |
162 | if (IS_ERR(vllist)) { | |
163 | ret = PTR_ERR(vllist); | |
8b2a464c DH |
164 | goto parse_failed; |
165 | } | |
00d3b7a4 | 166 | |
d5c32c89 DH |
167 | vllist->source = DNS_RECORD_FROM_CONFIG; |
168 | vllist->status = DNS_LOOKUP_NOT_DONE; | |
989782dc | 169 | cell->dns_expiry = TIME64_MAX; |
ded2f4c5 | 170 | } else { |
ca1cbbdc DH |
171 | ret = -ENOMEM; |
172 | vllist = afs_alloc_vlserver_list(0); | |
173 | if (!vllist) | |
174 | goto error; | |
d5c32c89 DH |
175 | vllist->source = DNS_RECORD_UNAVAILABLE; |
176 | vllist->status = DNS_LOOKUP_NOT_DONE; | |
ded2f4c5 | 177 | cell->dns_expiry = ktime_get_real_seconds(); |
00d3b7a4 | 178 | } |
00d3b7a4 | 179 | |
ca1cbbdc DH |
180 | rcu_assign_pointer(cell->vl_servers, vllist); |
181 | ||
d5c32c89 DH |
182 | cell->dns_source = vllist->source; |
183 | cell->dns_status = vllist->status; | |
184 | smp_store_release(&cell->dns_lookup_count, 1); /* vs source/status */ | |
185 | ||
00d3b7a4 DH |
186 | _leave(" = %p", cell); |
187 | return cell; | |
188 | ||
8b2a464c DH |
189 | parse_failed: |
190 | if (ret == -EINVAL) | |
191 | printk(KERN_ERR "kAFS: bad VL server IP address\n"); | |
ca1cbbdc | 192 | error: |
00d3b7a4 DH |
193 | kfree(cell); |
194 | _leave(" = %d", ret); | |
195 | return ERR_PTR(ret); | |
196 | } | |
1da177e4 | 197 | |
00d3b7a4 | 198 | /* |
989782dc | 199 | * afs_lookup_cell - Look up or create a cell record. |
f044c884 | 200 | * @net: The network namespace |
989782dc DH |
201 | * @name: The name of the cell. |
202 | * @namesz: The strlen of the cell name. | |
203 | * @vllist: A colon/comma separated list of numeric IP addresses or NULL. | |
204 | * @excl: T if an error should be given if the cell name already exists. | |
205 | * | |
206 | * Look up a cell record by name and query the DNS for VL server addresses if | |
207 | * needed. Note that that actual DNS query is punted off to the manager thread | |
208 | * so that this function can return immediately if interrupted whilst allowing | |
209 | * cell records to be shared even if not yet fully constructed. | |
00d3b7a4 | 210 | */ |
989782dc DH |
211 | struct afs_cell *afs_lookup_cell(struct afs_net *net, |
212 | const char *name, unsigned int namesz, | |
213 | const char *vllist, bool excl) | |
00d3b7a4 | 214 | { |
989782dc DH |
215 | struct afs_cell *cell, *candidate, *cursor; |
216 | struct rb_node *parent, **pp; | |
d5c32c89 | 217 | enum afs_cell_state state; |
989782dc DH |
218 | int ret, n; |
219 | ||
220 | _enter("%s,%s", name, vllist); | |
221 | ||
222 | if (!excl) { | |
223 | rcu_read_lock(); | |
224 | cell = afs_lookup_cell_rcu(net, name, namesz); | |
225 | rcu_read_unlock(); | |
68327951 | 226 | if (!IS_ERR(cell)) |
989782dc | 227 | goto wait_for_cell; |
989782dc | 228 | } |
00d3b7a4 | 229 | |
989782dc DH |
230 | /* Assume we're probably going to create a cell and preallocate and |
231 | * mostly set up a candidate record. We can then use this to stash the | |
232 | * name, the net namespace and VL server addresses. | |
233 | * | |
234 | * We also want to do this before we hold any locks as it may involve | |
235 | * upcalling to userspace to make DNS queries. | |
236 | */ | |
237 | candidate = afs_alloc_cell(net, name, namesz, vllist); | |
238 | if (IS_ERR(candidate)) { | |
239 | _leave(" = %ld", PTR_ERR(candidate)); | |
240 | return candidate; | |
5214b729 | 241 | } |
5214b729 | 242 | |
989782dc DH |
243 | /* Find the insertion point and check to see if someone else added a |
244 | * cell whilst we were allocating. | |
245 | */ | |
246 | write_seqlock(&net->cells_lock); | |
247 | ||
248 | pp = &net->cells.rb_node; | |
249 | parent = NULL; | |
250 | while (*pp) { | |
251 | parent = *pp; | |
252 | cursor = rb_entry(parent, struct afs_cell, net_node); | |
253 | ||
254 | n = strncasecmp(cursor->name, name, | |
255 | min_t(size_t, cursor->name_len, namesz)); | |
256 | if (n == 0) | |
257 | n = cursor->name_len - namesz; | |
258 | if (n < 0) | |
259 | pp = &(*pp)->rb_left; | |
260 | else if (n > 0) | |
261 | pp = &(*pp)->rb_right; | |
262 | else | |
263 | goto cell_already_exists; | |
00d3b7a4 DH |
264 | } |
265 | ||
989782dc DH |
266 | cell = candidate; |
267 | candidate = NULL; | |
268 | rb_link_node_rcu(&cell->net_node, parent, pp); | |
269 | rb_insert_color(&cell->net_node, &net->cells); | |
270 | atomic_inc(&net->cells_outstanding); | |
271 | write_sequnlock(&net->cells_lock); | |
1da177e4 | 272 | |
989782dc | 273 | queue_work(afs_wq, &cell->manager); |
1da177e4 | 274 | |
989782dc DH |
275 | wait_for_cell: |
276 | _debug("wait_for_cell"); | |
d5c32c89 DH |
277 | wait_var_event(&cell->state, |
278 | ({ | |
279 | state = smp_load_acquire(&cell->state); /* vs error */ | |
280 | state == AFS_CELL_ACTIVE || state == AFS_CELL_FAILED; | |
281 | })); | |
282 | ||
283 | /* Check the state obtained from the wait check. */ | |
284 | if (state == AFS_CELL_FAILED) { | |
989782dc DH |
285 | ret = cell->error; |
286 | goto error; | |
989782dc | 287 | } |
1da177e4 | 288 | |
989782dc | 289 | _leave(" = %p [cell]", cell); |
08e0e7c8 | 290 | return cell; |
1da177e4 | 291 | |
989782dc DH |
292 | cell_already_exists: |
293 | _debug("cell exists"); | |
294 | cell = cursor; | |
295 | if (excl) { | |
296 | ret = -EEXIST; | |
297 | } else { | |
989782dc DH |
298 | afs_get_cell(cursor); |
299 | ret = 0; | |
300 | } | |
301 | write_sequnlock(&net->cells_lock); | |
302 | kfree(candidate); | |
303 | if (ret == 0) | |
304 | goto wait_for_cell; | |
8b2a464c | 305 | goto error_noput; |
ec26815a | 306 | error: |
989782dc | 307 | afs_put_cell(net, cell); |
8b2a464c | 308 | error_noput: |
989782dc | 309 | _leave(" = %d [error]", ret); |
08e0e7c8 | 310 | return ERR_PTR(ret); |
ec26815a | 311 | } |
1da177e4 | 312 | |
1da177e4 | 313 | /* |
08e0e7c8 DH |
314 | * set the root cell information |
315 | * - can be called with a module parameter string | |
316 | * - can be called from a write to /proc/fs/afs/rootcell | |
1da177e4 | 317 | */ |
989782dc | 318 | int afs_cell_init(struct afs_net *net, const char *rootcell) |
1da177e4 LT |
319 | { |
320 | struct afs_cell *old_root, *new_root; | |
989782dc DH |
321 | const char *cp, *vllist; |
322 | size_t len; | |
1da177e4 LT |
323 | |
324 | _enter(""); | |
325 | ||
326 | if (!rootcell) { | |
327 | /* module is loaded with no parameters, or built statically. | |
328 | * - in the future we might initialize cell DB here. | |
329 | */ | |
08e0e7c8 | 330 | _leave(" = 0 [no root]"); |
1da177e4 LT |
331 | return 0; |
332 | } | |
333 | ||
334 | cp = strchr(rootcell, ':'); | |
989782dc | 335 | if (!cp) { |
07567a55 | 336 | _debug("kAFS: no VL server IP addresses specified"); |
989782dc DH |
337 | vllist = NULL; |
338 | len = strlen(rootcell); | |
339 | } else { | |
340 | vllist = cp + 1; | |
341 | len = cp - rootcell; | |
342 | } | |
1da177e4 LT |
343 | |
344 | /* allocate a cell record for the root cell */ | |
989782dc | 345 | new_root = afs_lookup_cell(net, rootcell, len, vllist, false); |
08e0e7c8 DH |
346 | if (IS_ERR(new_root)) { |
347 | _leave(" = %ld", PTR_ERR(new_root)); | |
348 | return PTR_ERR(new_root); | |
1da177e4 LT |
349 | } |
350 | ||
17814aef DH |
351 | if (!test_and_set_bit(AFS_CELL_FL_NO_GC, &new_root->flags)) |
352 | afs_get_cell(new_root); | |
989782dc | 353 | |
08e0e7c8 | 354 | /* install the new cell */ |
989782dc | 355 | write_seqlock(&net->cells_lock); |
1588def9 DH |
356 | old_root = rcu_access_pointer(net->ws_cell); |
357 | rcu_assign_pointer(net->ws_cell, new_root); | |
989782dc | 358 | write_sequnlock(&net->cells_lock); |
1da177e4 | 359 | |
989782dc | 360 | afs_put_cell(net, old_root); |
08e0e7c8 DH |
361 | _leave(" = 0"); |
362 | return 0; | |
ec26815a | 363 | } |
1da177e4 | 364 | |
1da177e4 | 365 | /* |
989782dc | 366 | * Update a cell's VL server address list from the DNS. |
1da177e4 | 367 | */ |
d5c32c89 | 368 | static int afs_update_cell(struct afs_cell *cell) |
1da177e4 | 369 | { |
d5c32c89 | 370 | struct afs_vlserver_list *vllist, *old = NULL, *p; |
ded2f4c5 DH |
371 | unsigned int min_ttl = READ_ONCE(afs_cell_min_ttl); |
372 | unsigned int max_ttl = READ_ONCE(afs_cell_max_ttl); | |
373 | time64_t now, expiry = 0; | |
d5c32c89 | 374 | int ret = 0; |
1da177e4 | 375 | |
989782dc DH |
376 | _enter("%s", cell->name); |
377 | ||
0a5143f2 | 378 | vllist = afs_dns_query(cell, &expiry); |
d5c32c89 DH |
379 | if (IS_ERR(vllist)) { |
380 | ret = PTR_ERR(vllist); | |
381 | ||
382 | _debug("%s: fail %d", cell->name, ret); | |
383 | if (ret == -ENOMEM) | |
384 | goto out_wake; | |
385 | ||
386 | ret = -ENOMEM; | |
387 | vllist = afs_alloc_vlserver_list(0); | |
388 | if (!vllist) | |
389 | goto out_wake; | |
390 | ||
391 | switch (ret) { | |
392 | case -ENODATA: | |
393 | case -EDESTADDRREQ: | |
394 | vllist->status = DNS_LOOKUP_GOT_NOT_FOUND; | |
395 | break; | |
396 | case -EAGAIN: | |
397 | case -ECONNREFUSED: | |
398 | vllist->status = DNS_LOOKUP_GOT_TEMP_FAILURE; | |
399 | break; | |
400 | default: | |
401 | vllist->status = DNS_LOOKUP_GOT_LOCAL_FAILURE; | |
402 | break; | |
403 | } | |
404 | } | |
405 | ||
406 | _debug("%s: got list %d %d", cell->name, vllist->source, vllist->status); | |
407 | cell->dns_status = vllist->status; | |
ded2f4c5 DH |
408 | |
409 | now = ktime_get_real_seconds(); | |
410 | if (min_ttl > max_ttl) | |
411 | max_ttl = min_ttl; | |
412 | if (expiry < now + min_ttl) | |
413 | expiry = now + min_ttl; | |
414 | else if (expiry > now + max_ttl) | |
415 | expiry = now + max_ttl; | |
416 | ||
d5c32c89 DH |
417 | _debug("%s: status %d", cell->name, vllist->status); |
418 | if (vllist->source == DNS_RECORD_UNAVAILABLE) { | |
419 | switch (vllist->status) { | |
420 | case DNS_LOOKUP_GOT_NOT_FOUND: | |
ded2f4c5 DH |
421 | /* The DNS said that the cell does not exist or there |
422 | * weren't any addresses to be had. | |
423 | */ | |
ded2f4c5 | 424 | cell->dns_expiry = expiry; |
8b2a464c | 425 | break; |
989782dc | 426 | |
d5c32c89 DH |
427 | case DNS_LOOKUP_BAD: |
428 | case DNS_LOOKUP_GOT_LOCAL_FAILURE: | |
429 | case DNS_LOOKUP_GOT_TEMP_FAILURE: | |
430 | case DNS_LOOKUP_GOT_NS_FAILURE: | |
8b2a464c | 431 | default: |
ded2f4c5 | 432 | cell->dns_expiry = now + 10; |
8b2a464c DH |
433 | break; |
434 | } | |
8b2a464c | 435 | } else { |
8b2a464c | 436 | cell->dns_expiry = expiry; |
8b2a464c | 437 | } |
bec5eb61 | 438 | |
d5c32c89 DH |
439 | /* Replace the VL server list if the new record has servers or the old |
440 | * record doesn't. | |
441 | */ | |
442 | write_lock(&cell->vl_servers_lock); | |
443 | p = rcu_dereference_protected(cell->vl_servers, true); | |
444 | if (vllist->nr_servers > 0 || p->nr_servers == 0) { | |
445 | rcu_assign_pointer(cell->vl_servers, vllist); | |
446 | cell->dns_source = vllist->source; | |
447 | old = p; | |
448 | } | |
449 | write_unlock(&cell->vl_servers_lock); | |
450 | afs_put_vlserverlist(cell->net, old); | |
bec5eb61 | 451 | |
d5c32c89 DH |
452 | out_wake: |
453 | smp_store_release(&cell->dns_lookup_count, | |
454 | cell->dns_lookup_count + 1); /* vs source/status */ | |
455 | wake_up_var(&cell->dns_lookup_count); | |
456 | _leave(" = %d", ret); | |
457 | return ret; | |
ec26815a | 458 | } |
1da177e4 | 459 | |
1da177e4 | 460 | /* |
989782dc | 461 | * Destroy a cell record |
1da177e4 | 462 | */ |
989782dc | 463 | static void afs_cell_destroy(struct rcu_head *rcu) |
1da177e4 | 464 | { |
989782dc | 465 | struct afs_cell *cell = container_of(rcu, struct afs_cell, rcu); |
1da177e4 | 466 | |
989782dc | 467 | _enter("%p{%s}", cell, cell->name); |
1da177e4 | 468 | |
989782dc DH |
469 | ASSERTCMP(atomic_read(&cell->usage), ==, 0); |
470 | ||
0a5143f2 | 471 | afs_put_vlserverlist(cell->net, rcu_access_pointer(cell->vl_servers)); |
989782dc DH |
472 | key_put(cell->anonymous_key); |
473 | kfree(cell); | |
474 | ||
475 | _leave(" [destroyed]"); | |
ec26815a | 476 | } |
1da177e4 | 477 | |
1da177e4 | 478 | /* |
989782dc | 479 | * Queue the cell manager. |
1da177e4 | 480 | */ |
989782dc | 481 | static void afs_queue_cell_manager(struct afs_net *net) |
1da177e4 | 482 | { |
989782dc | 483 | int outstanding = atomic_inc_return(&net->cells_outstanding); |
1da177e4 | 484 | |
989782dc | 485 | _enter("%d", outstanding); |
1da177e4 | 486 | |
989782dc DH |
487 | if (!queue_work(afs_wq, &net->cells_manager)) |
488 | afs_dec_cells_outstanding(net); | |
489 | } | |
490 | ||
491 | /* | |
492 | * Cell management timer. We have an increment on cells_outstanding that we | |
493 | * need to pass along to the work item. | |
494 | */ | |
495 | void afs_cells_timer(struct timer_list *timer) | |
496 | { | |
497 | struct afs_net *net = container_of(timer, struct afs_net, cells_timer); | |
498 | ||
499 | _enter(""); | |
500 | if (!queue_work(afs_wq, &net->cells_manager)) | |
501 | afs_dec_cells_outstanding(net); | |
502 | } | |
1da177e4 | 503 | |
8b2a464c DH |
504 | /* |
505 | * Get a reference on a cell record. | |
506 | */ | |
507 | struct afs_cell *afs_get_cell(struct afs_cell *cell) | |
508 | { | |
509 | atomic_inc(&cell->usage); | |
510 | return cell; | |
511 | } | |
512 | ||
989782dc DH |
513 | /* |
514 | * Drop a reference on a cell record. | |
515 | */ | |
516 | void afs_put_cell(struct afs_net *net, struct afs_cell *cell) | |
517 | { | |
518 | time64_t now, expire_delay; | |
1da177e4 | 519 | |
989782dc | 520 | if (!cell) |
1da177e4 | 521 | return; |
1da177e4 | 522 | |
989782dc | 523 | _enter("%s", cell->name); |
08e0e7c8 | 524 | |
989782dc DH |
525 | now = ktime_get_real_seconds(); |
526 | cell->last_inactive = now; | |
527 | expire_delay = 0; | |
d5c32c89 | 528 | if (cell->vl_servers->nr_servers) |
989782dc | 529 | expire_delay = afs_cell_gc_delay; |
1da177e4 | 530 | |
989782dc DH |
531 | if (atomic_dec_return(&cell->usage) > 1) |
532 | return; | |
1da177e4 | 533 | |
989782dc DH |
534 | /* 'cell' may now be garbage collected. */ |
535 | afs_set_cell_timer(net, expire_delay); | |
ec26815a | 536 | } |
1da177e4 | 537 | |
1da177e4 | 538 | /* |
989782dc | 539 | * Allocate a key to use as a placeholder for anonymous user security. |
1da177e4 | 540 | */ |
989782dc | 541 | static int afs_alloc_anon_key(struct afs_cell *cell) |
1da177e4 | 542 | { |
989782dc DH |
543 | struct key *key; |
544 | char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp; | |
1da177e4 | 545 | |
989782dc DH |
546 | /* Create a key to represent an anonymous user. */ |
547 | memcpy(keyname, "afs@", 4); | |
548 | dp = keyname + 4; | |
549 | cp = cell->name; | |
550 | do { | |
551 | *dp++ = tolower(*cp); | |
552 | } while (*cp++); | |
1da177e4 | 553 | |
989782dc DH |
554 | key = rxrpc_get_null_key(keyname); |
555 | if (IS_ERR(key)) | |
556 | return PTR_ERR(key); | |
1da177e4 | 557 | |
989782dc | 558 | cell->anonymous_key = key; |
1da177e4 | 559 | |
989782dc DH |
560 | _debug("anon key %p{%x}", |
561 | cell->anonymous_key, key_serial(cell->anonymous_key)); | |
562 | return 0; | |
563 | } | |
1da177e4 | 564 | |
989782dc DH |
565 | /* |
566 | * Activate a cell. | |
567 | */ | |
568 | static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell) | |
569 | { | |
6b3944e4 DH |
570 | struct hlist_node **p; |
571 | struct afs_cell *pcell; | |
989782dc DH |
572 | int ret; |
573 | ||
574 | if (!cell->anonymous_key) { | |
575 | ret = afs_alloc_anon_key(cell); | |
576 | if (ret < 0) | |
577 | return ret; | |
08e0e7c8 DH |
578 | } |
579 | ||
989782dc DH |
580 | #ifdef CONFIG_AFS_FSCACHE |
581 | cell->cache = fscache_acquire_cookie(afs_cache_netfs.primary_index, | |
582 | &afs_cell_cache_index_def, | |
402cb8dd DH |
583 | cell->name, strlen(cell->name), |
584 | NULL, 0, | |
ee1235a9 | 585 | cell, 0, true); |
989782dc | 586 | #endif |
5b86d4ff | 587 | ret = afs_proc_cell_setup(cell); |
989782dc DH |
588 | if (ret < 0) |
589 | return ret; | |
0da0b7fd DH |
590 | |
591 | mutex_lock(&net->proc_cells_lock); | |
6b3944e4 DH |
592 | for (p = &net->proc_cells.first; *p; p = &(*p)->next) { |
593 | pcell = hlist_entry(*p, struct afs_cell, proc_link); | |
594 | if (strcmp(cell->name, pcell->name) < 0) | |
595 | break; | |
596 | } | |
597 | ||
598 | cell->proc_link.pprev = p; | |
599 | cell->proc_link.next = *p; | |
600 | rcu_assign_pointer(*p, &cell->proc_link.next); | |
601 | if (cell->proc_link.next) | |
602 | cell->proc_link.next->pprev = &cell->proc_link.next; | |
603 | ||
0da0b7fd DH |
604 | afs_dynroot_mkdir(net, cell); |
605 | mutex_unlock(&net->proc_cells_lock); | |
989782dc DH |
606 | return 0; |
607 | } | |
608 | ||
609 | /* | |
610 | * Deactivate a cell. | |
611 | */ | |
612 | static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell) | |
613 | { | |
614 | _enter("%s", cell->name); | |
1da177e4 | 615 | |
5b86d4ff | 616 | afs_proc_cell_remove(cell); |
1da177e4 | 617 | |
0da0b7fd | 618 | mutex_lock(&net->proc_cells_lock); |
6b3944e4 | 619 | hlist_del_rcu(&cell->proc_link); |
0da0b7fd DH |
620 | afs_dynroot_rmdir(net, cell); |
621 | mutex_unlock(&net->proc_cells_lock); | |
1da177e4 | 622 | |
9b3f26c9 | 623 | #ifdef CONFIG_AFS_FSCACHE |
402cb8dd | 624 | fscache_relinquish_cookie(cell->cache, NULL, false); |
989782dc | 625 | cell->cache = NULL; |
1da177e4 | 626 | #endif |
1da177e4 | 627 | |
989782dc | 628 | _leave(""); |
ec26815a | 629 | } |
1da177e4 | 630 | |
1da177e4 | 631 | /* |
989782dc DH |
632 | * Manage a cell record, initialising and destroying it, maintaining its DNS |
633 | * records. | |
1da177e4 | 634 | */ |
989782dc | 635 | static void afs_manage_cell(struct work_struct *work) |
1da177e4 | 636 | { |
989782dc DH |
637 | struct afs_cell *cell = container_of(work, struct afs_cell, manager); |
638 | struct afs_net *net = cell->net; | |
639 | bool deleted; | |
640 | int ret, usage; | |
641 | ||
642 | _enter("%s", cell->name); | |
643 | ||
644 | again: | |
645 | _debug("state %u", cell->state); | |
646 | switch (cell->state) { | |
647 | case AFS_CELL_INACTIVE: | |
648 | case AFS_CELL_FAILED: | |
649 | write_seqlock(&net->cells_lock); | |
650 | usage = 1; | |
651 | deleted = atomic_try_cmpxchg_relaxed(&cell->usage, &usage, 0); | |
652 | if (deleted) | |
653 | rb_erase(&cell->net_node, &net->cells); | |
654 | write_sequnlock(&net->cells_lock); | |
655 | if (deleted) | |
656 | goto final_destruction; | |
657 | if (cell->state == AFS_CELL_FAILED) | |
658 | goto done; | |
d5c32c89 DH |
659 | smp_store_release(&cell->state, AFS_CELL_UNSET); |
660 | wake_up_var(&cell->state); | |
989782dc DH |
661 | goto again; |
662 | ||
663 | case AFS_CELL_UNSET: | |
d5c32c89 DH |
664 | smp_store_release(&cell->state, AFS_CELL_ACTIVATING); |
665 | wake_up_var(&cell->state); | |
989782dc DH |
666 | goto again; |
667 | ||
668 | case AFS_CELL_ACTIVATING: | |
669 | ret = afs_activate_cell(net, cell); | |
670 | if (ret < 0) | |
671 | goto activation_failed; | |
672 | ||
d5c32c89 DH |
673 | smp_store_release(&cell->state, AFS_CELL_ACTIVE); |
674 | wake_up_var(&cell->state); | |
989782dc DH |
675 | goto again; |
676 | ||
677 | case AFS_CELL_ACTIVE: | |
678 | if (atomic_read(&cell->usage) > 1) { | |
d5c32c89 DH |
679 | if (test_and_clear_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) { |
680 | ret = afs_update_cell(cell); | |
681 | if (ret < 0) | |
682 | cell->error = ret; | |
683 | } | |
989782dc DH |
684 | goto done; |
685 | } | |
d5c32c89 DH |
686 | smp_store_release(&cell->state, AFS_CELL_DEACTIVATING); |
687 | wake_up_var(&cell->state); | |
989782dc DH |
688 | goto again; |
689 | ||
690 | case AFS_CELL_DEACTIVATING: | |
989782dc DH |
691 | if (atomic_read(&cell->usage) > 1) |
692 | goto reverse_deactivation; | |
693 | afs_deactivate_cell(net, cell); | |
d5c32c89 DH |
694 | smp_store_release(&cell->state, AFS_CELL_INACTIVE); |
695 | wake_up_var(&cell->state); | |
989782dc DH |
696 | goto again; |
697 | ||
698 | default: | |
699 | break; | |
700 | } | |
701 | _debug("bad state %u", cell->state); | |
702 | BUG(); /* Unhandled state */ | |
703 | ||
704 | activation_failed: | |
705 | cell->error = ret; | |
706 | afs_deactivate_cell(net, cell); | |
707 | ||
d5c32c89 DH |
708 | smp_store_release(&cell->state, AFS_CELL_FAILED); /* vs error */ |
709 | wake_up_var(&cell->state); | |
989782dc DH |
710 | goto again; |
711 | ||
712 | reverse_deactivation: | |
d5c32c89 DH |
713 | smp_store_release(&cell->state, AFS_CELL_ACTIVE); |
714 | wake_up_var(&cell->state); | |
989782dc DH |
715 | _leave(" [deact->act]"); |
716 | return; | |
717 | ||
718 | done: | |
719 | _leave(" [done %u]", cell->state); | |
720 | return; | |
721 | ||
722 | final_destruction: | |
723 | call_rcu(&cell->rcu, afs_cell_destroy); | |
724 | afs_dec_cells_outstanding(net); | |
725 | _leave(" [destruct %d]", atomic_read(&net->cells_outstanding)); | |
726 | } | |
727 | ||
728 | /* | |
729 | * Manage the records of cells known to a network namespace. This includes | |
730 | * updating the DNS records and garbage collecting unused cells that were | |
731 | * automatically added. | |
732 | * | |
733 | * Note that constructed cell records may only be removed from net->cells by | |
734 | * this work item, so it is safe for this work item to stash a cursor pointing | |
735 | * into the tree and then return to caller (provided it skips cells that are | |
736 | * still under construction). | |
737 | * | |
738 | * Note also that we were given an increment on net->cells_outstanding by | |
739 | * whoever queued us that we need to deal with before returning. | |
740 | */ | |
741 | void afs_manage_cells(struct work_struct *work) | |
742 | { | |
743 | struct afs_net *net = container_of(work, struct afs_net, cells_manager); | |
744 | struct rb_node *cursor; | |
745 | time64_t now = ktime_get_real_seconds(), next_manage = TIME64_MAX; | |
746 | bool purging = !net->live; | |
1da177e4 LT |
747 | |
748 | _enter(""); | |
749 | ||
989782dc DH |
750 | /* Trawl the cell database looking for cells that have expired from |
751 | * lack of use and cells whose DNS results have expired and dispatch | |
752 | * their managers. | |
753 | */ | |
754 | read_seqlock_excl(&net->cells_lock); | |
1da177e4 | 755 | |
989782dc DH |
756 | for (cursor = rb_first(&net->cells); cursor; cursor = rb_next(cursor)) { |
757 | struct afs_cell *cell = | |
758 | rb_entry(cursor, struct afs_cell, net_node); | |
759 | unsigned usage; | |
760 | bool sched_cell = false; | |
08e0e7c8 | 761 | |
989782dc DH |
762 | usage = atomic_read(&cell->usage); |
763 | _debug("manage %s %u", cell->name, usage); | |
764 | ||
765 | ASSERTCMP(usage, >=, 1); | |
766 | ||
767 | if (purging) { | |
768 | if (test_and_clear_bit(AFS_CELL_FL_NO_GC, &cell->flags)) | |
769 | usage = atomic_dec_return(&cell->usage); | |
770 | ASSERTCMP(usage, ==, 1); | |
771 | } | |
1da177e4 | 772 | |
989782dc | 773 | if (usage == 1) { |
d5c32c89 | 774 | struct afs_vlserver_list *vllist; |
989782dc | 775 | time64_t expire_at = cell->last_inactive; |
1da177e4 | 776 | |
d5c32c89 DH |
777 | read_lock(&cell->vl_servers_lock); |
778 | vllist = rcu_dereference_protected( | |
779 | cell->vl_servers, | |
780 | lockdep_is_held(&cell->vl_servers_lock)); | |
781 | if (vllist->nr_servers > 0) | |
989782dc | 782 | expire_at += afs_cell_gc_delay; |
d5c32c89 | 783 | read_unlock(&cell->vl_servers_lock); |
989782dc DH |
784 | if (purging || expire_at <= now) |
785 | sched_cell = true; | |
786 | else if (expire_at < next_manage) | |
787 | next_manage = expire_at; | |
1da177e4 LT |
788 | } |
789 | ||
989782dc | 790 | if (!purging) { |
d5c32c89 | 791 | if (test_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) |
989782dc | 792 | sched_cell = true; |
989782dc DH |
793 | } |
794 | ||
795 | if (sched_cell) | |
796 | queue_work(afs_wq, &cell->manager); | |
797 | } | |
798 | ||
799 | read_sequnlock_excl(&net->cells_lock); | |
1da177e4 | 800 | |
989782dc DH |
801 | /* Update the timer on the way out. We have to pass an increment on |
802 | * cells_outstanding in the namespace that we are in to the timer or | |
803 | * the work scheduler. | |
804 | */ | |
805 | if (!purging && next_manage < TIME64_MAX) { | |
806 | now = ktime_get_real_seconds(); | |
1da177e4 | 807 | |
989782dc DH |
808 | if (next_manage - now <= 0) { |
809 | if (queue_work(afs_wq, &net->cells_manager)) | |
810 | atomic_inc(&net->cells_outstanding); | |
811 | } else { | |
812 | afs_set_cell_timer(net, next_manage - now); | |
1da177e4 LT |
813 | } |
814 | } | |
815 | ||
989782dc DH |
816 | afs_dec_cells_outstanding(net); |
817 | _leave(" [%d]", atomic_read(&net->cells_outstanding)); | |
818 | } | |
819 | ||
820 | /* | |
821 | * Purge in-memory cell database. | |
822 | */ | |
823 | void afs_cell_purge(struct afs_net *net) | |
824 | { | |
825 | struct afs_cell *ws; | |
826 | ||
827 | _enter(""); | |
828 | ||
829 | write_seqlock(&net->cells_lock); | |
1588def9 DH |
830 | ws = rcu_access_pointer(net->ws_cell); |
831 | RCU_INIT_POINTER(net->ws_cell, NULL); | |
989782dc DH |
832 | write_sequnlock(&net->cells_lock); |
833 | afs_put_cell(net, ws); | |
834 | ||
835 | _debug("del timer"); | |
836 | if (del_timer_sync(&net->cells_timer)) | |
837 | atomic_dec(&net->cells_outstanding); | |
838 | ||
839 | _debug("kick mgr"); | |
840 | afs_queue_cell_manager(net); | |
841 | ||
842 | _debug("wait"); | |
ab1fbe32 PZ |
843 | wait_var_event(&net->cells_outstanding, |
844 | !atomic_read(&net->cells_outstanding)); | |
1da177e4 | 845 | _leave(""); |
ec26815a | 846 | } |