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); | |
a5fb8e6c | 77 | ret = 0; |
fe342cf7 | 78 | break; |
989782dc DH |
79 | } |
80 | ret = -EDESTADDRREQ; | |
81 | continue; | |
82 | } | |
83 | ||
84 | p = rcu_dereference_raw(net->cells.rb_node); | |
85 | while (p) { | |
86 | cell = rb_entry(p, struct afs_cell, net_node); | |
87 | ||
88 | n = strncasecmp(cell->name, name, | |
89 | min_t(size_t, cell->name_len, namesz)); | |
90 | if (n == 0) | |
91 | n = cell->name_len - namesz; | |
92 | if (n < 0) { | |
93 | p = rcu_dereference_raw(p->rb_left); | |
94 | } else if (n > 0) { | |
95 | p = rcu_dereference_raw(p->rb_right); | |
96 | } else { | |
97 | if (atomic_inc_not_zero(&cell->usage)) { | |
98 | ret = 0; | |
99 | break; | |
100 | } | |
101 | /* We want to repeat the search, this time with | |
102 | * the lock properly locked. | |
103 | */ | |
104 | } | |
105 | cell = NULL; | |
106 | } | |
1da177e4 | 107 | |
989782dc | 108 | } while (need_seqretry(&net->cells_lock, seq)); |
1da177e4 | 109 | |
989782dc | 110 | done_seqretry(&net->cells_lock, seq); |
1da177e4 | 111 | |
a5fb8e6c DH |
112 | if (ret != 0 && cell) |
113 | afs_put_cell(net, cell); | |
114 | ||
989782dc DH |
115 | return ret == 0 ? cell : ERR_PTR(ret); |
116 | } | |
117 | ||
118 | /* | |
119 | * Set up a cell record and fill in its name, VL server address list and | |
120 | * allocate an anonymous key | |
121 | */ | |
122 | static struct afs_cell *afs_alloc_cell(struct afs_net *net, | |
123 | const char *name, unsigned int namelen, | |
0a5143f2 | 124 | const char *addresses) |
989782dc | 125 | { |
ca1cbbdc | 126 | struct afs_vlserver_list *vllist; |
989782dc DH |
127 | struct afs_cell *cell; |
128 | int i, ret; | |
129 | ||
130 | ASSERT(name); | |
131 | if (namelen == 0) | |
132 | return ERR_PTR(-EINVAL); | |
07567a55 WL |
133 | if (namelen > AFS_MAXCELLNAME) { |
134 | _leave(" = -ENAMETOOLONG"); | |
00d3b7a4 | 135 | return ERR_PTR(-ENAMETOOLONG); |
07567a55 | 136 | } |
37ab6368 DH |
137 | if (namelen == 5 && memcmp(name, "@cell", 5) == 0) |
138 | return ERR_PTR(-EINVAL); | |
00d3b7a4 | 139 | |
0a5143f2 | 140 | _enter("%*.*s,%s", namelen, namelen, name, addresses); |
989782dc DH |
141 | |
142 | cell = kzalloc(sizeof(struct afs_cell), GFP_KERNEL); | |
1da177e4 LT |
143 | if (!cell) { |
144 | _leave(" = -ENOMEM"); | |
08e0e7c8 | 145 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
146 | } |
147 | ||
f044c884 | 148 | cell->net = net; |
989782dc DH |
149 | cell->name_len = namelen; |
150 | for (i = 0; i < namelen; i++) | |
151 | cell->name[i] = tolower(name[i]); | |
152 | ||
153 | atomic_set(&cell->usage, 2); | |
154 | INIT_WORK(&cell->manager, afs_manage_cell); | |
d2ddc776 DH |
155 | INIT_LIST_HEAD(&cell->proc_volumes); |
156 | rwlock_init(&cell->proc_lock); | |
0a5143f2 | 157 | rwlock_init(&cell->vl_servers_lock); |
4d9df986 | 158 | |
ca1cbbdc DH |
159 | /* Provide a VL server list, filling it in if we were given a list of |
160 | * addresses to use. | |
989782dc | 161 | */ |
0a5143f2 | 162 | if (addresses) { |
0a5143f2 DH |
163 | vllist = afs_parse_text_addrs(net, |
164 | addresses, strlen(addresses), ':', | |
165 | VL_SERVICE, AFS_VL_PORT); | |
166 | if (IS_ERR(vllist)) { | |
167 | ret = PTR_ERR(vllist); | |
8b2a464c DH |
168 | goto parse_failed; |
169 | } | |
00d3b7a4 | 170 | |
d5c32c89 DH |
171 | vllist->source = DNS_RECORD_FROM_CONFIG; |
172 | vllist->status = DNS_LOOKUP_NOT_DONE; | |
989782dc | 173 | cell->dns_expiry = TIME64_MAX; |
ded2f4c5 | 174 | } else { |
ca1cbbdc DH |
175 | ret = -ENOMEM; |
176 | vllist = afs_alloc_vlserver_list(0); | |
177 | if (!vllist) | |
178 | goto error; | |
d5c32c89 DH |
179 | vllist->source = DNS_RECORD_UNAVAILABLE; |
180 | vllist->status = DNS_LOOKUP_NOT_DONE; | |
ded2f4c5 | 181 | cell->dns_expiry = ktime_get_real_seconds(); |
00d3b7a4 | 182 | } |
00d3b7a4 | 183 | |
ca1cbbdc DH |
184 | rcu_assign_pointer(cell->vl_servers, vllist); |
185 | ||
d5c32c89 DH |
186 | cell->dns_source = vllist->source; |
187 | cell->dns_status = vllist->status; | |
188 | smp_store_release(&cell->dns_lookup_count, 1); /* vs source/status */ | |
189 | ||
00d3b7a4 DH |
190 | _leave(" = %p", cell); |
191 | return cell; | |
192 | ||
8b2a464c DH |
193 | parse_failed: |
194 | if (ret == -EINVAL) | |
195 | printk(KERN_ERR "kAFS: bad VL server IP address\n"); | |
ca1cbbdc | 196 | error: |
00d3b7a4 DH |
197 | kfree(cell); |
198 | _leave(" = %d", ret); | |
199 | return ERR_PTR(ret); | |
200 | } | |
1da177e4 | 201 | |
00d3b7a4 | 202 | /* |
989782dc | 203 | * afs_lookup_cell - Look up or create a cell record. |
f044c884 | 204 | * @net: The network namespace |
989782dc DH |
205 | * @name: The name of the cell. |
206 | * @namesz: The strlen of the cell name. | |
207 | * @vllist: A colon/comma separated list of numeric IP addresses or NULL. | |
208 | * @excl: T if an error should be given if the cell name already exists. | |
209 | * | |
210 | * Look up a cell record by name and query the DNS for VL server addresses if | |
211 | * needed. Note that that actual DNS query is punted off to the manager thread | |
212 | * so that this function can return immediately if interrupted whilst allowing | |
213 | * cell records to be shared even if not yet fully constructed. | |
00d3b7a4 | 214 | */ |
989782dc DH |
215 | struct afs_cell *afs_lookup_cell(struct afs_net *net, |
216 | const char *name, unsigned int namesz, | |
217 | const char *vllist, bool excl) | |
00d3b7a4 | 218 | { |
989782dc DH |
219 | struct afs_cell *cell, *candidate, *cursor; |
220 | struct rb_node *parent, **pp; | |
d5c32c89 | 221 | enum afs_cell_state state; |
989782dc DH |
222 | int ret, n; |
223 | ||
224 | _enter("%s,%s", name, vllist); | |
225 | ||
226 | if (!excl) { | |
227 | rcu_read_lock(); | |
228 | cell = afs_lookup_cell_rcu(net, name, namesz); | |
229 | rcu_read_unlock(); | |
68327951 | 230 | if (!IS_ERR(cell)) |
989782dc | 231 | goto wait_for_cell; |
989782dc | 232 | } |
00d3b7a4 | 233 | |
989782dc DH |
234 | /* Assume we're probably going to create a cell and preallocate and |
235 | * mostly set up a candidate record. We can then use this to stash the | |
236 | * name, the net namespace and VL server addresses. | |
237 | * | |
238 | * We also want to do this before we hold any locks as it may involve | |
239 | * upcalling to userspace to make DNS queries. | |
240 | */ | |
241 | candidate = afs_alloc_cell(net, name, namesz, vllist); | |
242 | if (IS_ERR(candidate)) { | |
243 | _leave(" = %ld", PTR_ERR(candidate)); | |
244 | return candidate; | |
5214b729 | 245 | } |
5214b729 | 246 | |
989782dc DH |
247 | /* Find the insertion point and check to see if someone else added a |
248 | * cell whilst we were allocating. | |
249 | */ | |
250 | write_seqlock(&net->cells_lock); | |
251 | ||
252 | pp = &net->cells.rb_node; | |
253 | parent = NULL; | |
254 | while (*pp) { | |
255 | parent = *pp; | |
256 | cursor = rb_entry(parent, struct afs_cell, net_node); | |
257 | ||
258 | n = strncasecmp(cursor->name, name, | |
259 | min_t(size_t, cursor->name_len, namesz)); | |
260 | if (n == 0) | |
261 | n = cursor->name_len - namesz; | |
262 | if (n < 0) | |
263 | pp = &(*pp)->rb_left; | |
264 | else if (n > 0) | |
265 | pp = &(*pp)->rb_right; | |
266 | else | |
267 | goto cell_already_exists; | |
00d3b7a4 DH |
268 | } |
269 | ||
989782dc DH |
270 | cell = candidate; |
271 | candidate = NULL; | |
272 | rb_link_node_rcu(&cell->net_node, parent, pp); | |
273 | rb_insert_color(&cell->net_node, &net->cells); | |
274 | atomic_inc(&net->cells_outstanding); | |
275 | write_sequnlock(&net->cells_lock); | |
1da177e4 | 276 | |
989782dc | 277 | queue_work(afs_wq, &cell->manager); |
1da177e4 | 278 | |
989782dc DH |
279 | wait_for_cell: |
280 | _debug("wait_for_cell"); | |
d5c32c89 DH |
281 | wait_var_event(&cell->state, |
282 | ({ | |
283 | state = smp_load_acquire(&cell->state); /* vs error */ | |
284 | state == AFS_CELL_ACTIVE || state == AFS_CELL_FAILED; | |
285 | })); | |
286 | ||
287 | /* Check the state obtained from the wait check. */ | |
288 | if (state == AFS_CELL_FAILED) { | |
989782dc DH |
289 | ret = cell->error; |
290 | goto error; | |
989782dc | 291 | } |
1da177e4 | 292 | |
989782dc | 293 | _leave(" = %p [cell]", cell); |
08e0e7c8 | 294 | return cell; |
1da177e4 | 295 | |
989782dc DH |
296 | cell_already_exists: |
297 | _debug("cell exists"); | |
298 | cell = cursor; | |
299 | if (excl) { | |
300 | ret = -EEXIST; | |
301 | } else { | |
989782dc DH |
302 | afs_get_cell(cursor); |
303 | ret = 0; | |
304 | } | |
305 | write_sequnlock(&net->cells_lock); | |
306 | kfree(candidate); | |
307 | if (ret == 0) | |
308 | goto wait_for_cell; | |
8b2a464c | 309 | goto error_noput; |
ec26815a | 310 | error: |
989782dc | 311 | afs_put_cell(net, cell); |
8b2a464c | 312 | error_noput: |
989782dc | 313 | _leave(" = %d [error]", ret); |
08e0e7c8 | 314 | return ERR_PTR(ret); |
ec26815a | 315 | } |
1da177e4 | 316 | |
1da177e4 | 317 | /* |
08e0e7c8 DH |
318 | * set the root cell information |
319 | * - can be called with a module parameter string | |
320 | * - can be called from a write to /proc/fs/afs/rootcell | |
1da177e4 | 321 | */ |
989782dc | 322 | int afs_cell_init(struct afs_net *net, const char *rootcell) |
1da177e4 LT |
323 | { |
324 | struct afs_cell *old_root, *new_root; | |
989782dc DH |
325 | const char *cp, *vllist; |
326 | size_t len; | |
1da177e4 LT |
327 | |
328 | _enter(""); | |
329 | ||
330 | if (!rootcell) { | |
331 | /* module is loaded with no parameters, or built statically. | |
332 | * - in the future we might initialize cell DB here. | |
333 | */ | |
08e0e7c8 | 334 | _leave(" = 0 [no root]"); |
1da177e4 LT |
335 | return 0; |
336 | } | |
337 | ||
338 | cp = strchr(rootcell, ':'); | |
989782dc | 339 | if (!cp) { |
07567a55 | 340 | _debug("kAFS: no VL server IP addresses specified"); |
989782dc DH |
341 | vllist = NULL; |
342 | len = strlen(rootcell); | |
343 | } else { | |
344 | vllist = cp + 1; | |
345 | len = cp - rootcell; | |
346 | } | |
1da177e4 LT |
347 | |
348 | /* allocate a cell record for the root cell */ | |
989782dc | 349 | new_root = afs_lookup_cell(net, rootcell, len, vllist, false); |
08e0e7c8 DH |
350 | if (IS_ERR(new_root)) { |
351 | _leave(" = %ld", PTR_ERR(new_root)); | |
352 | return PTR_ERR(new_root); | |
1da177e4 LT |
353 | } |
354 | ||
17814aef DH |
355 | if (!test_and_set_bit(AFS_CELL_FL_NO_GC, &new_root->flags)) |
356 | afs_get_cell(new_root); | |
989782dc | 357 | |
08e0e7c8 | 358 | /* install the new cell */ |
989782dc | 359 | write_seqlock(&net->cells_lock); |
1588def9 DH |
360 | old_root = rcu_access_pointer(net->ws_cell); |
361 | rcu_assign_pointer(net->ws_cell, new_root); | |
989782dc | 362 | write_sequnlock(&net->cells_lock); |
1da177e4 | 363 | |
989782dc | 364 | afs_put_cell(net, old_root); |
08e0e7c8 DH |
365 | _leave(" = 0"); |
366 | return 0; | |
ec26815a | 367 | } |
1da177e4 | 368 | |
1da177e4 | 369 | /* |
989782dc | 370 | * Update a cell's VL server address list from the DNS. |
1da177e4 | 371 | */ |
d5c32c89 | 372 | static int afs_update_cell(struct afs_cell *cell) |
1da177e4 | 373 | { |
d5c32c89 | 374 | struct afs_vlserver_list *vllist, *old = NULL, *p; |
ded2f4c5 DH |
375 | unsigned int min_ttl = READ_ONCE(afs_cell_min_ttl); |
376 | unsigned int max_ttl = READ_ONCE(afs_cell_max_ttl); | |
377 | time64_t now, expiry = 0; | |
d5c32c89 | 378 | int ret = 0; |
1da177e4 | 379 | |
989782dc DH |
380 | _enter("%s", cell->name); |
381 | ||
0a5143f2 | 382 | vllist = afs_dns_query(cell, &expiry); |
d5c32c89 DH |
383 | if (IS_ERR(vllist)) { |
384 | ret = PTR_ERR(vllist); | |
385 | ||
386 | _debug("%s: fail %d", cell->name, ret); | |
387 | if (ret == -ENOMEM) | |
388 | goto out_wake; | |
389 | ||
390 | ret = -ENOMEM; | |
391 | vllist = afs_alloc_vlserver_list(0); | |
392 | if (!vllist) | |
393 | goto out_wake; | |
394 | ||
395 | switch (ret) { | |
396 | case -ENODATA: | |
397 | case -EDESTADDRREQ: | |
398 | vllist->status = DNS_LOOKUP_GOT_NOT_FOUND; | |
399 | break; | |
400 | case -EAGAIN: | |
401 | case -ECONNREFUSED: | |
402 | vllist->status = DNS_LOOKUP_GOT_TEMP_FAILURE; | |
403 | break; | |
404 | default: | |
405 | vllist->status = DNS_LOOKUP_GOT_LOCAL_FAILURE; | |
406 | break; | |
407 | } | |
408 | } | |
409 | ||
410 | _debug("%s: got list %d %d", cell->name, vllist->source, vllist->status); | |
411 | cell->dns_status = vllist->status; | |
ded2f4c5 DH |
412 | |
413 | now = ktime_get_real_seconds(); | |
414 | if (min_ttl > max_ttl) | |
415 | max_ttl = min_ttl; | |
416 | if (expiry < now + min_ttl) | |
417 | expiry = now + min_ttl; | |
418 | else if (expiry > now + max_ttl) | |
419 | expiry = now + max_ttl; | |
420 | ||
d5c32c89 DH |
421 | _debug("%s: status %d", cell->name, vllist->status); |
422 | if (vllist->source == DNS_RECORD_UNAVAILABLE) { | |
423 | switch (vllist->status) { | |
424 | case DNS_LOOKUP_GOT_NOT_FOUND: | |
ded2f4c5 DH |
425 | /* The DNS said that the cell does not exist or there |
426 | * weren't any addresses to be had. | |
427 | */ | |
ded2f4c5 | 428 | cell->dns_expiry = expiry; |
8b2a464c | 429 | break; |
989782dc | 430 | |
d5c32c89 DH |
431 | case DNS_LOOKUP_BAD: |
432 | case DNS_LOOKUP_GOT_LOCAL_FAILURE: | |
433 | case DNS_LOOKUP_GOT_TEMP_FAILURE: | |
434 | case DNS_LOOKUP_GOT_NS_FAILURE: | |
8b2a464c | 435 | default: |
ded2f4c5 | 436 | cell->dns_expiry = now + 10; |
8b2a464c DH |
437 | break; |
438 | } | |
8b2a464c | 439 | } else { |
8b2a464c | 440 | cell->dns_expiry = expiry; |
8b2a464c | 441 | } |
bec5eb61 | 442 | |
d5c32c89 DH |
443 | /* Replace the VL server list if the new record has servers or the old |
444 | * record doesn't. | |
445 | */ | |
446 | write_lock(&cell->vl_servers_lock); | |
447 | p = rcu_dereference_protected(cell->vl_servers, true); | |
448 | if (vllist->nr_servers > 0 || p->nr_servers == 0) { | |
449 | rcu_assign_pointer(cell->vl_servers, vllist); | |
450 | cell->dns_source = vllist->source; | |
451 | old = p; | |
452 | } | |
453 | write_unlock(&cell->vl_servers_lock); | |
454 | afs_put_vlserverlist(cell->net, old); | |
bec5eb61 | 455 | |
d5c32c89 DH |
456 | out_wake: |
457 | smp_store_release(&cell->dns_lookup_count, | |
458 | cell->dns_lookup_count + 1); /* vs source/status */ | |
459 | wake_up_var(&cell->dns_lookup_count); | |
460 | _leave(" = %d", ret); | |
461 | return ret; | |
ec26815a | 462 | } |
1da177e4 | 463 | |
1da177e4 | 464 | /* |
989782dc | 465 | * Destroy a cell record |
1da177e4 | 466 | */ |
989782dc | 467 | static void afs_cell_destroy(struct rcu_head *rcu) |
1da177e4 | 468 | { |
989782dc | 469 | struct afs_cell *cell = container_of(rcu, struct afs_cell, rcu); |
1da177e4 | 470 | |
989782dc | 471 | _enter("%p{%s}", cell, cell->name); |
1da177e4 | 472 | |
989782dc DH |
473 | ASSERTCMP(atomic_read(&cell->usage), ==, 0); |
474 | ||
0a5143f2 | 475 | afs_put_vlserverlist(cell->net, rcu_access_pointer(cell->vl_servers)); |
989782dc DH |
476 | key_put(cell->anonymous_key); |
477 | kfree(cell); | |
478 | ||
479 | _leave(" [destroyed]"); | |
ec26815a | 480 | } |
1da177e4 | 481 | |
1da177e4 | 482 | /* |
989782dc | 483 | * Queue the cell manager. |
1da177e4 | 484 | */ |
989782dc | 485 | static void afs_queue_cell_manager(struct afs_net *net) |
1da177e4 | 486 | { |
989782dc | 487 | int outstanding = atomic_inc_return(&net->cells_outstanding); |
1da177e4 | 488 | |
989782dc | 489 | _enter("%d", outstanding); |
1da177e4 | 490 | |
989782dc DH |
491 | if (!queue_work(afs_wq, &net->cells_manager)) |
492 | afs_dec_cells_outstanding(net); | |
493 | } | |
494 | ||
495 | /* | |
496 | * Cell management timer. We have an increment on cells_outstanding that we | |
497 | * need to pass along to the work item. | |
498 | */ | |
499 | void afs_cells_timer(struct timer_list *timer) | |
500 | { | |
501 | struct afs_net *net = container_of(timer, struct afs_net, cells_timer); | |
502 | ||
503 | _enter(""); | |
504 | if (!queue_work(afs_wq, &net->cells_manager)) | |
505 | afs_dec_cells_outstanding(net); | |
506 | } | |
1da177e4 | 507 | |
8b2a464c DH |
508 | /* |
509 | * Get a reference on a cell record. | |
510 | */ | |
511 | struct afs_cell *afs_get_cell(struct afs_cell *cell) | |
512 | { | |
513 | atomic_inc(&cell->usage); | |
514 | return cell; | |
515 | } | |
516 | ||
989782dc DH |
517 | /* |
518 | * Drop a reference on a cell record. | |
519 | */ | |
520 | void afs_put_cell(struct afs_net *net, struct afs_cell *cell) | |
521 | { | |
522 | time64_t now, expire_delay; | |
1da177e4 | 523 | |
989782dc | 524 | if (!cell) |
1da177e4 | 525 | return; |
1da177e4 | 526 | |
989782dc | 527 | _enter("%s", cell->name); |
08e0e7c8 | 528 | |
989782dc DH |
529 | now = ktime_get_real_seconds(); |
530 | cell->last_inactive = now; | |
531 | expire_delay = 0; | |
d5c32c89 | 532 | if (cell->vl_servers->nr_servers) |
989782dc | 533 | expire_delay = afs_cell_gc_delay; |
1da177e4 | 534 | |
989782dc DH |
535 | if (atomic_dec_return(&cell->usage) > 1) |
536 | return; | |
1da177e4 | 537 | |
989782dc DH |
538 | /* 'cell' may now be garbage collected. */ |
539 | afs_set_cell_timer(net, expire_delay); | |
ec26815a | 540 | } |
1da177e4 | 541 | |
1da177e4 | 542 | /* |
989782dc | 543 | * Allocate a key to use as a placeholder for anonymous user security. |
1da177e4 | 544 | */ |
989782dc | 545 | static int afs_alloc_anon_key(struct afs_cell *cell) |
1da177e4 | 546 | { |
989782dc DH |
547 | struct key *key; |
548 | char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp; | |
1da177e4 | 549 | |
989782dc DH |
550 | /* Create a key to represent an anonymous user. */ |
551 | memcpy(keyname, "afs@", 4); | |
552 | dp = keyname + 4; | |
553 | cp = cell->name; | |
554 | do { | |
555 | *dp++ = tolower(*cp); | |
556 | } while (*cp++); | |
1da177e4 | 557 | |
989782dc DH |
558 | key = rxrpc_get_null_key(keyname); |
559 | if (IS_ERR(key)) | |
560 | return PTR_ERR(key); | |
1da177e4 | 561 | |
989782dc | 562 | cell->anonymous_key = key; |
1da177e4 | 563 | |
989782dc DH |
564 | _debug("anon key %p{%x}", |
565 | cell->anonymous_key, key_serial(cell->anonymous_key)); | |
566 | return 0; | |
567 | } | |
1da177e4 | 568 | |
989782dc DH |
569 | /* |
570 | * Activate a cell. | |
571 | */ | |
572 | static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell) | |
573 | { | |
6b3944e4 DH |
574 | struct hlist_node **p; |
575 | struct afs_cell *pcell; | |
989782dc DH |
576 | int ret; |
577 | ||
578 | if (!cell->anonymous_key) { | |
579 | ret = afs_alloc_anon_key(cell); | |
580 | if (ret < 0) | |
581 | return ret; | |
08e0e7c8 DH |
582 | } |
583 | ||
989782dc DH |
584 | #ifdef CONFIG_AFS_FSCACHE |
585 | cell->cache = fscache_acquire_cookie(afs_cache_netfs.primary_index, | |
586 | &afs_cell_cache_index_def, | |
402cb8dd DH |
587 | cell->name, strlen(cell->name), |
588 | NULL, 0, | |
ee1235a9 | 589 | cell, 0, true); |
989782dc | 590 | #endif |
5b86d4ff | 591 | ret = afs_proc_cell_setup(cell); |
989782dc DH |
592 | if (ret < 0) |
593 | return ret; | |
0da0b7fd DH |
594 | |
595 | mutex_lock(&net->proc_cells_lock); | |
6b3944e4 DH |
596 | for (p = &net->proc_cells.first; *p; p = &(*p)->next) { |
597 | pcell = hlist_entry(*p, struct afs_cell, proc_link); | |
598 | if (strcmp(cell->name, pcell->name) < 0) | |
599 | break; | |
600 | } | |
601 | ||
602 | cell->proc_link.pprev = p; | |
603 | cell->proc_link.next = *p; | |
604 | rcu_assign_pointer(*p, &cell->proc_link.next); | |
605 | if (cell->proc_link.next) | |
606 | cell->proc_link.next->pprev = &cell->proc_link.next; | |
607 | ||
0da0b7fd DH |
608 | afs_dynroot_mkdir(net, cell); |
609 | mutex_unlock(&net->proc_cells_lock); | |
989782dc DH |
610 | return 0; |
611 | } | |
612 | ||
613 | /* | |
614 | * Deactivate a cell. | |
615 | */ | |
616 | static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell) | |
617 | { | |
618 | _enter("%s", cell->name); | |
1da177e4 | 619 | |
5b86d4ff | 620 | afs_proc_cell_remove(cell); |
1da177e4 | 621 | |
0da0b7fd | 622 | mutex_lock(&net->proc_cells_lock); |
6b3944e4 | 623 | hlist_del_rcu(&cell->proc_link); |
0da0b7fd DH |
624 | afs_dynroot_rmdir(net, cell); |
625 | mutex_unlock(&net->proc_cells_lock); | |
1da177e4 | 626 | |
9b3f26c9 | 627 | #ifdef CONFIG_AFS_FSCACHE |
402cb8dd | 628 | fscache_relinquish_cookie(cell->cache, NULL, false); |
989782dc | 629 | cell->cache = NULL; |
1da177e4 | 630 | #endif |
1da177e4 | 631 | |
989782dc | 632 | _leave(""); |
ec26815a | 633 | } |
1da177e4 | 634 | |
1da177e4 | 635 | /* |
989782dc DH |
636 | * Manage a cell record, initialising and destroying it, maintaining its DNS |
637 | * records. | |
1da177e4 | 638 | */ |
989782dc | 639 | static void afs_manage_cell(struct work_struct *work) |
1da177e4 | 640 | { |
989782dc DH |
641 | struct afs_cell *cell = container_of(work, struct afs_cell, manager); |
642 | struct afs_net *net = cell->net; | |
643 | bool deleted; | |
644 | int ret, usage; | |
645 | ||
646 | _enter("%s", cell->name); | |
647 | ||
648 | again: | |
649 | _debug("state %u", cell->state); | |
650 | switch (cell->state) { | |
651 | case AFS_CELL_INACTIVE: | |
652 | case AFS_CELL_FAILED: | |
653 | write_seqlock(&net->cells_lock); | |
654 | usage = 1; | |
655 | deleted = atomic_try_cmpxchg_relaxed(&cell->usage, &usage, 0); | |
656 | if (deleted) | |
657 | rb_erase(&cell->net_node, &net->cells); | |
658 | write_sequnlock(&net->cells_lock); | |
659 | if (deleted) | |
660 | goto final_destruction; | |
661 | if (cell->state == AFS_CELL_FAILED) | |
662 | goto done; | |
d5c32c89 DH |
663 | smp_store_release(&cell->state, AFS_CELL_UNSET); |
664 | wake_up_var(&cell->state); | |
989782dc DH |
665 | goto again; |
666 | ||
667 | case AFS_CELL_UNSET: | |
d5c32c89 DH |
668 | smp_store_release(&cell->state, AFS_CELL_ACTIVATING); |
669 | wake_up_var(&cell->state); | |
989782dc DH |
670 | goto again; |
671 | ||
672 | case AFS_CELL_ACTIVATING: | |
673 | ret = afs_activate_cell(net, cell); | |
674 | if (ret < 0) | |
675 | goto activation_failed; | |
676 | ||
d5c32c89 DH |
677 | smp_store_release(&cell->state, AFS_CELL_ACTIVE); |
678 | wake_up_var(&cell->state); | |
989782dc DH |
679 | goto again; |
680 | ||
681 | case AFS_CELL_ACTIVE: | |
682 | if (atomic_read(&cell->usage) > 1) { | |
d5c32c89 DH |
683 | if (test_and_clear_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) { |
684 | ret = afs_update_cell(cell); | |
685 | if (ret < 0) | |
686 | cell->error = ret; | |
687 | } | |
989782dc DH |
688 | goto done; |
689 | } | |
d5c32c89 DH |
690 | smp_store_release(&cell->state, AFS_CELL_DEACTIVATING); |
691 | wake_up_var(&cell->state); | |
989782dc DH |
692 | goto again; |
693 | ||
694 | case AFS_CELL_DEACTIVATING: | |
989782dc DH |
695 | if (atomic_read(&cell->usage) > 1) |
696 | goto reverse_deactivation; | |
697 | afs_deactivate_cell(net, cell); | |
d5c32c89 DH |
698 | smp_store_release(&cell->state, AFS_CELL_INACTIVE); |
699 | wake_up_var(&cell->state); | |
989782dc DH |
700 | goto again; |
701 | ||
702 | default: | |
703 | break; | |
704 | } | |
705 | _debug("bad state %u", cell->state); | |
706 | BUG(); /* Unhandled state */ | |
707 | ||
708 | activation_failed: | |
709 | cell->error = ret; | |
710 | afs_deactivate_cell(net, cell); | |
711 | ||
d5c32c89 DH |
712 | smp_store_release(&cell->state, AFS_CELL_FAILED); /* vs error */ |
713 | wake_up_var(&cell->state); | |
989782dc DH |
714 | goto again; |
715 | ||
716 | reverse_deactivation: | |
d5c32c89 DH |
717 | smp_store_release(&cell->state, AFS_CELL_ACTIVE); |
718 | wake_up_var(&cell->state); | |
989782dc DH |
719 | _leave(" [deact->act]"); |
720 | return; | |
721 | ||
722 | done: | |
723 | _leave(" [done %u]", cell->state); | |
724 | return; | |
725 | ||
726 | final_destruction: | |
727 | call_rcu(&cell->rcu, afs_cell_destroy); | |
728 | afs_dec_cells_outstanding(net); | |
729 | _leave(" [destruct %d]", atomic_read(&net->cells_outstanding)); | |
730 | } | |
731 | ||
732 | /* | |
733 | * Manage the records of cells known to a network namespace. This includes | |
734 | * updating the DNS records and garbage collecting unused cells that were | |
735 | * automatically added. | |
736 | * | |
737 | * Note that constructed cell records may only be removed from net->cells by | |
738 | * this work item, so it is safe for this work item to stash a cursor pointing | |
739 | * into the tree and then return to caller (provided it skips cells that are | |
740 | * still under construction). | |
741 | * | |
742 | * Note also that we were given an increment on net->cells_outstanding by | |
743 | * whoever queued us that we need to deal with before returning. | |
744 | */ | |
745 | void afs_manage_cells(struct work_struct *work) | |
746 | { | |
747 | struct afs_net *net = container_of(work, struct afs_net, cells_manager); | |
748 | struct rb_node *cursor; | |
749 | time64_t now = ktime_get_real_seconds(), next_manage = TIME64_MAX; | |
750 | bool purging = !net->live; | |
1da177e4 LT |
751 | |
752 | _enter(""); | |
753 | ||
989782dc DH |
754 | /* Trawl the cell database looking for cells that have expired from |
755 | * lack of use and cells whose DNS results have expired and dispatch | |
756 | * their managers. | |
757 | */ | |
758 | read_seqlock_excl(&net->cells_lock); | |
1da177e4 | 759 | |
989782dc DH |
760 | for (cursor = rb_first(&net->cells); cursor; cursor = rb_next(cursor)) { |
761 | struct afs_cell *cell = | |
762 | rb_entry(cursor, struct afs_cell, net_node); | |
763 | unsigned usage; | |
764 | bool sched_cell = false; | |
08e0e7c8 | 765 | |
989782dc DH |
766 | usage = atomic_read(&cell->usage); |
767 | _debug("manage %s %u", cell->name, usage); | |
768 | ||
769 | ASSERTCMP(usage, >=, 1); | |
770 | ||
771 | if (purging) { | |
772 | if (test_and_clear_bit(AFS_CELL_FL_NO_GC, &cell->flags)) | |
773 | usage = atomic_dec_return(&cell->usage); | |
774 | ASSERTCMP(usage, ==, 1); | |
775 | } | |
1da177e4 | 776 | |
989782dc | 777 | if (usage == 1) { |
d5c32c89 | 778 | struct afs_vlserver_list *vllist; |
989782dc | 779 | time64_t expire_at = cell->last_inactive; |
1da177e4 | 780 | |
d5c32c89 DH |
781 | read_lock(&cell->vl_servers_lock); |
782 | vllist = rcu_dereference_protected( | |
783 | cell->vl_servers, | |
784 | lockdep_is_held(&cell->vl_servers_lock)); | |
785 | if (vllist->nr_servers > 0) | |
989782dc | 786 | expire_at += afs_cell_gc_delay; |
d5c32c89 | 787 | read_unlock(&cell->vl_servers_lock); |
989782dc DH |
788 | if (purging || expire_at <= now) |
789 | sched_cell = true; | |
790 | else if (expire_at < next_manage) | |
791 | next_manage = expire_at; | |
1da177e4 LT |
792 | } |
793 | ||
989782dc | 794 | if (!purging) { |
d5c32c89 | 795 | if (test_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) |
989782dc | 796 | sched_cell = true; |
989782dc DH |
797 | } |
798 | ||
799 | if (sched_cell) | |
800 | queue_work(afs_wq, &cell->manager); | |
801 | } | |
802 | ||
803 | read_sequnlock_excl(&net->cells_lock); | |
1da177e4 | 804 | |
989782dc DH |
805 | /* Update the timer on the way out. We have to pass an increment on |
806 | * cells_outstanding in the namespace that we are in to the timer or | |
807 | * the work scheduler. | |
808 | */ | |
809 | if (!purging && next_manage < TIME64_MAX) { | |
810 | now = ktime_get_real_seconds(); | |
1da177e4 | 811 | |
989782dc DH |
812 | if (next_manage - now <= 0) { |
813 | if (queue_work(afs_wq, &net->cells_manager)) | |
814 | atomic_inc(&net->cells_outstanding); | |
815 | } else { | |
816 | afs_set_cell_timer(net, next_manage - now); | |
1da177e4 LT |
817 | } |
818 | } | |
819 | ||
989782dc DH |
820 | afs_dec_cells_outstanding(net); |
821 | _leave(" [%d]", atomic_read(&net->cells_outstanding)); | |
822 | } | |
823 | ||
824 | /* | |
825 | * Purge in-memory cell database. | |
826 | */ | |
827 | void afs_cell_purge(struct afs_net *net) | |
828 | { | |
829 | struct afs_cell *ws; | |
830 | ||
831 | _enter(""); | |
832 | ||
833 | write_seqlock(&net->cells_lock); | |
1588def9 DH |
834 | ws = rcu_access_pointer(net->ws_cell); |
835 | RCU_INIT_POINTER(net->ws_cell, NULL); | |
989782dc DH |
836 | write_sequnlock(&net->cells_lock); |
837 | afs_put_cell(net, ws); | |
838 | ||
839 | _debug("del timer"); | |
840 | if (del_timer_sync(&net->cells_timer)) | |
841 | atomic_dec(&net->cells_outstanding); | |
842 | ||
843 | _debug("kick mgr"); | |
844 | afs_queue_cell_manager(net); | |
845 | ||
846 | _debug("wait"); | |
ab1fbe32 PZ |
847 | wait_var_event(&net->cells_outstanding, |
848 | !atomic_read(&net->cells_outstanding)); | |
1da177e4 | 849 | _leave(""); |
ec26815a | 850 | } |