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 | } |
a45ea48e DH |
137 | |
138 | /* Prohibit cell names that contain unprintable chars, '/' and '@' or | |
139 | * that begin with a dot. This also precludes "@cell". | |
140 | */ | |
141 | if (name[0] == '.') | |
37ab6368 | 142 | return ERR_PTR(-EINVAL); |
a45ea48e DH |
143 | for (i = 0; i < namelen; i++) { |
144 | char ch = name[i]; | |
145 | if (!isprint(ch) || ch == '/' || ch == '@') | |
146 | return ERR_PTR(-EINVAL); | |
147 | } | |
00d3b7a4 | 148 | |
0a5143f2 | 149 | _enter("%*.*s,%s", namelen, namelen, name, addresses); |
989782dc DH |
150 | |
151 | cell = kzalloc(sizeof(struct afs_cell), GFP_KERNEL); | |
1da177e4 LT |
152 | if (!cell) { |
153 | _leave(" = -ENOMEM"); | |
08e0e7c8 | 154 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
155 | } |
156 | ||
f044c884 | 157 | cell->net = net; |
989782dc DH |
158 | cell->name_len = namelen; |
159 | for (i = 0; i < namelen; i++) | |
160 | cell->name[i] = tolower(name[i]); | |
161 | ||
162 | atomic_set(&cell->usage, 2); | |
163 | INIT_WORK(&cell->manager, afs_manage_cell); | |
d2ddc776 DH |
164 | INIT_LIST_HEAD(&cell->proc_volumes); |
165 | rwlock_init(&cell->proc_lock); | |
0a5143f2 | 166 | rwlock_init(&cell->vl_servers_lock); |
4d9df986 | 167 | |
ca1cbbdc DH |
168 | /* Provide a VL server list, filling it in if we were given a list of |
169 | * addresses to use. | |
989782dc | 170 | */ |
0a5143f2 | 171 | if (addresses) { |
0a5143f2 DH |
172 | vllist = afs_parse_text_addrs(net, |
173 | addresses, strlen(addresses), ':', | |
174 | VL_SERVICE, AFS_VL_PORT); | |
175 | if (IS_ERR(vllist)) { | |
176 | ret = PTR_ERR(vllist); | |
8b2a464c DH |
177 | goto parse_failed; |
178 | } | |
00d3b7a4 | 179 | |
d5c32c89 DH |
180 | vllist->source = DNS_RECORD_FROM_CONFIG; |
181 | vllist->status = DNS_LOOKUP_NOT_DONE; | |
989782dc | 182 | cell->dns_expiry = TIME64_MAX; |
ded2f4c5 | 183 | } else { |
ca1cbbdc DH |
184 | ret = -ENOMEM; |
185 | vllist = afs_alloc_vlserver_list(0); | |
186 | if (!vllist) | |
187 | goto error; | |
d5c32c89 DH |
188 | vllist->source = DNS_RECORD_UNAVAILABLE; |
189 | vllist->status = DNS_LOOKUP_NOT_DONE; | |
ded2f4c5 | 190 | cell->dns_expiry = ktime_get_real_seconds(); |
00d3b7a4 | 191 | } |
00d3b7a4 | 192 | |
ca1cbbdc DH |
193 | rcu_assign_pointer(cell->vl_servers, vllist); |
194 | ||
d5c32c89 DH |
195 | cell->dns_source = vllist->source; |
196 | cell->dns_status = vllist->status; | |
197 | smp_store_release(&cell->dns_lookup_count, 1); /* vs source/status */ | |
198 | ||
00d3b7a4 DH |
199 | _leave(" = %p", cell); |
200 | return cell; | |
201 | ||
8b2a464c DH |
202 | parse_failed: |
203 | if (ret == -EINVAL) | |
204 | printk(KERN_ERR "kAFS: bad VL server IP address\n"); | |
ca1cbbdc | 205 | error: |
00d3b7a4 DH |
206 | kfree(cell); |
207 | _leave(" = %d", ret); | |
208 | return ERR_PTR(ret); | |
209 | } | |
1da177e4 | 210 | |
00d3b7a4 | 211 | /* |
989782dc | 212 | * afs_lookup_cell - Look up or create a cell record. |
f044c884 | 213 | * @net: The network namespace |
989782dc DH |
214 | * @name: The name of the cell. |
215 | * @namesz: The strlen of the cell name. | |
216 | * @vllist: A colon/comma separated list of numeric IP addresses or NULL. | |
217 | * @excl: T if an error should be given if the cell name already exists. | |
218 | * | |
219 | * Look up a cell record by name and query the DNS for VL server addresses if | |
220 | * needed. Note that that actual DNS query is punted off to the manager thread | |
221 | * so that this function can return immediately if interrupted whilst allowing | |
222 | * cell records to be shared even if not yet fully constructed. | |
00d3b7a4 | 223 | */ |
989782dc DH |
224 | struct afs_cell *afs_lookup_cell(struct afs_net *net, |
225 | const char *name, unsigned int namesz, | |
226 | const char *vllist, bool excl) | |
00d3b7a4 | 227 | { |
989782dc DH |
228 | struct afs_cell *cell, *candidate, *cursor; |
229 | struct rb_node *parent, **pp; | |
d5c32c89 | 230 | enum afs_cell_state state; |
989782dc DH |
231 | int ret, n; |
232 | ||
233 | _enter("%s,%s", name, vllist); | |
234 | ||
235 | if (!excl) { | |
236 | rcu_read_lock(); | |
237 | cell = afs_lookup_cell_rcu(net, name, namesz); | |
238 | rcu_read_unlock(); | |
68327951 | 239 | if (!IS_ERR(cell)) |
989782dc | 240 | goto wait_for_cell; |
989782dc | 241 | } |
00d3b7a4 | 242 | |
989782dc DH |
243 | /* Assume we're probably going to create a cell and preallocate and |
244 | * mostly set up a candidate record. We can then use this to stash the | |
245 | * name, the net namespace and VL server addresses. | |
246 | * | |
247 | * We also want to do this before we hold any locks as it may involve | |
248 | * upcalling to userspace to make DNS queries. | |
249 | */ | |
250 | candidate = afs_alloc_cell(net, name, namesz, vllist); | |
251 | if (IS_ERR(candidate)) { | |
252 | _leave(" = %ld", PTR_ERR(candidate)); | |
253 | return candidate; | |
5214b729 | 254 | } |
5214b729 | 255 | |
989782dc DH |
256 | /* Find the insertion point and check to see if someone else added a |
257 | * cell whilst we were allocating. | |
258 | */ | |
259 | write_seqlock(&net->cells_lock); | |
260 | ||
261 | pp = &net->cells.rb_node; | |
262 | parent = NULL; | |
263 | while (*pp) { | |
264 | parent = *pp; | |
265 | cursor = rb_entry(parent, struct afs_cell, net_node); | |
266 | ||
267 | n = strncasecmp(cursor->name, name, | |
268 | min_t(size_t, cursor->name_len, namesz)); | |
269 | if (n == 0) | |
270 | n = cursor->name_len - namesz; | |
271 | if (n < 0) | |
272 | pp = &(*pp)->rb_left; | |
273 | else if (n > 0) | |
274 | pp = &(*pp)->rb_right; | |
275 | else | |
276 | goto cell_already_exists; | |
00d3b7a4 DH |
277 | } |
278 | ||
989782dc DH |
279 | cell = candidate; |
280 | candidate = NULL; | |
281 | rb_link_node_rcu(&cell->net_node, parent, pp); | |
282 | rb_insert_color(&cell->net_node, &net->cells); | |
283 | atomic_inc(&net->cells_outstanding); | |
284 | write_sequnlock(&net->cells_lock); | |
1da177e4 | 285 | |
989782dc | 286 | queue_work(afs_wq, &cell->manager); |
1da177e4 | 287 | |
989782dc DH |
288 | wait_for_cell: |
289 | _debug("wait_for_cell"); | |
d5c32c89 DH |
290 | wait_var_event(&cell->state, |
291 | ({ | |
292 | state = smp_load_acquire(&cell->state); /* vs error */ | |
293 | state == AFS_CELL_ACTIVE || state == AFS_CELL_FAILED; | |
294 | })); | |
295 | ||
296 | /* Check the state obtained from the wait check. */ | |
297 | if (state == AFS_CELL_FAILED) { | |
989782dc DH |
298 | ret = cell->error; |
299 | goto error; | |
989782dc | 300 | } |
1da177e4 | 301 | |
989782dc | 302 | _leave(" = %p [cell]", cell); |
08e0e7c8 | 303 | return cell; |
1da177e4 | 304 | |
989782dc DH |
305 | cell_already_exists: |
306 | _debug("cell exists"); | |
307 | cell = cursor; | |
308 | if (excl) { | |
309 | ret = -EEXIST; | |
310 | } else { | |
989782dc DH |
311 | afs_get_cell(cursor); |
312 | ret = 0; | |
313 | } | |
314 | write_sequnlock(&net->cells_lock); | |
315 | kfree(candidate); | |
316 | if (ret == 0) | |
317 | goto wait_for_cell; | |
8b2a464c | 318 | goto error_noput; |
ec26815a | 319 | error: |
989782dc | 320 | afs_put_cell(net, cell); |
8b2a464c | 321 | error_noput: |
989782dc | 322 | _leave(" = %d [error]", ret); |
08e0e7c8 | 323 | return ERR_PTR(ret); |
ec26815a | 324 | } |
1da177e4 | 325 | |
1da177e4 | 326 | /* |
08e0e7c8 DH |
327 | * set the root cell information |
328 | * - can be called with a module parameter string | |
329 | * - can be called from a write to /proc/fs/afs/rootcell | |
1da177e4 | 330 | */ |
989782dc | 331 | int afs_cell_init(struct afs_net *net, const char *rootcell) |
1da177e4 LT |
332 | { |
333 | struct afs_cell *old_root, *new_root; | |
989782dc DH |
334 | const char *cp, *vllist; |
335 | size_t len; | |
1da177e4 LT |
336 | |
337 | _enter(""); | |
338 | ||
339 | if (!rootcell) { | |
340 | /* module is loaded with no parameters, or built statically. | |
341 | * - in the future we might initialize cell DB here. | |
342 | */ | |
08e0e7c8 | 343 | _leave(" = 0 [no root]"); |
1da177e4 LT |
344 | return 0; |
345 | } | |
346 | ||
347 | cp = strchr(rootcell, ':'); | |
989782dc | 348 | if (!cp) { |
07567a55 | 349 | _debug("kAFS: no VL server IP addresses specified"); |
989782dc DH |
350 | vllist = NULL; |
351 | len = strlen(rootcell); | |
352 | } else { | |
353 | vllist = cp + 1; | |
354 | len = cp - rootcell; | |
355 | } | |
1da177e4 LT |
356 | |
357 | /* allocate a cell record for the root cell */ | |
989782dc | 358 | new_root = afs_lookup_cell(net, rootcell, len, vllist, false); |
08e0e7c8 DH |
359 | if (IS_ERR(new_root)) { |
360 | _leave(" = %ld", PTR_ERR(new_root)); | |
361 | return PTR_ERR(new_root); | |
1da177e4 LT |
362 | } |
363 | ||
17814aef DH |
364 | if (!test_and_set_bit(AFS_CELL_FL_NO_GC, &new_root->flags)) |
365 | afs_get_cell(new_root); | |
989782dc | 366 | |
08e0e7c8 | 367 | /* install the new cell */ |
989782dc | 368 | write_seqlock(&net->cells_lock); |
1588def9 DH |
369 | old_root = rcu_access_pointer(net->ws_cell); |
370 | rcu_assign_pointer(net->ws_cell, new_root); | |
989782dc | 371 | write_sequnlock(&net->cells_lock); |
1da177e4 | 372 | |
989782dc | 373 | afs_put_cell(net, old_root); |
08e0e7c8 DH |
374 | _leave(" = 0"); |
375 | return 0; | |
ec26815a | 376 | } |
1da177e4 | 377 | |
1da177e4 | 378 | /* |
989782dc | 379 | * Update a cell's VL server address list from the DNS. |
1da177e4 | 380 | */ |
d5c32c89 | 381 | static int afs_update_cell(struct afs_cell *cell) |
1da177e4 | 382 | { |
d5c32c89 | 383 | struct afs_vlserver_list *vllist, *old = NULL, *p; |
ded2f4c5 DH |
384 | unsigned int min_ttl = READ_ONCE(afs_cell_min_ttl); |
385 | unsigned int max_ttl = READ_ONCE(afs_cell_max_ttl); | |
386 | time64_t now, expiry = 0; | |
d5c32c89 | 387 | int ret = 0; |
1da177e4 | 388 | |
989782dc DH |
389 | _enter("%s", cell->name); |
390 | ||
0a5143f2 | 391 | vllist = afs_dns_query(cell, &expiry); |
d5c32c89 DH |
392 | if (IS_ERR(vllist)) { |
393 | ret = PTR_ERR(vllist); | |
394 | ||
395 | _debug("%s: fail %d", cell->name, ret); | |
396 | if (ret == -ENOMEM) | |
397 | goto out_wake; | |
398 | ||
399 | ret = -ENOMEM; | |
400 | vllist = afs_alloc_vlserver_list(0); | |
401 | if (!vllist) | |
402 | goto out_wake; | |
403 | ||
404 | switch (ret) { | |
405 | case -ENODATA: | |
406 | case -EDESTADDRREQ: | |
407 | vllist->status = DNS_LOOKUP_GOT_NOT_FOUND; | |
408 | break; | |
409 | case -EAGAIN: | |
410 | case -ECONNREFUSED: | |
411 | vllist->status = DNS_LOOKUP_GOT_TEMP_FAILURE; | |
412 | break; | |
413 | default: | |
414 | vllist->status = DNS_LOOKUP_GOT_LOCAL_FAILURE; | |
415 | break; | |
416 | } | |
417 | } | |
418 | ||
419 | _debug("%s: got list %d %d", cell->name, vllist->source, vllist->status); | |
420 | cell->dns_status = vllist->status; | |
ded2f4c5 DH |
421 | |
422 | now = ktime_get_real_seconds(); | |
423 | if (min_ttl > max_ttl) | |
424 | max_ttl = min_ttl; | |
425 | if (expiry < now + min_ttl) | |
426 | expiry = now + min_ttl; | |
427 | else if (expiry > now + max_ttl) | |
428 | expiry = now + max_ttl; | |
429 | ||
d5c32c89 DH |
430 | _debug("%s: status %d", cell->name, vllist->status); |
431 | if (vllist->source == DNS_RECORD_UNAVAILABLE) { | |
432 | switch (vllist->status) { | |
433 | case DNS_LOOKUP_GOT_NOT_FOUND: | |
ded2f4c5 DH |
434 | /* The DNS said that the cell does not exist or there |
435 | * weren't any addresses to be had. | |
436 | */ | |
ded2f4c5 | 437 | cell->dns_expiry = expiry; |
8b2a464c | 438 | break; |
989782dc | 439 | |
d5c32c89 DH |
440 | case DNS_LOOKUP_BAD: |
441 | case DNS_LOOKUP_GOT_LOCAL_FAILURE: | |
442 | case DNS_LOOKUP_GOT_TEMP_FAILURE: | |
443 | case DNS_LOOKUP_GOT_NS_FAILURE: | |
8b2a464c | 444 | default: |
ded2f4c5 | 445 | cell->dns_expiry = now + 10; |
8b2a464c DH |
446 | break; |
447 | } | |
8b2a464c | 448 | } else { |
8b2a464c | 449 | cell->dns_expiry = expiry; |
8b2a464c | 450 | } |
bec5eb61 | 451 | |
d5c32c89 DH |
452 | /* Replace the VL server list if the new record has servers or the old |
453 | * record doesn't. | |
454 | */ | |
455 | write_lock(&cell->vl_servers_lock); | |
456 | p = rcu_dereference_protected(cell->vl_servers, true); | |
457 | if (vllist->nr_servers > 0 || p->nr_servers == 0) { | |
458 | rcu_assign_pointer(cell->vl_servers, vllist); | |
459 | cell->dns_source = vllist->source; | |
460 | old = p; | |
461 | } | |
462 | write_unlock(&cell->vl_servers_lock); | |
463 | afs_put_vlserverlist(cell->net, old); | |
bec5eb61 | 464 | |
d5c32c89 DH |
465 | out_wake: |
466 | smp_store_release(&cell->dns_lookup_count, | |
467 | cell->dns_lookup_count + 1); /* vs source/status */ | |
468 | wake_up_var(&cell->dns_lookup_count); | |
469 | _leave(" = %d", ret); | |
470 | return ret; | |
ec26815a | 471 | } |
1da177e4 | 472 | |
1da177e4 | 473 | /* |
989782dc | 474 | * Destroy a cell record |
1da177e4 | 475 | */ |
989782dc | 476 | static void afs_cell_destroy(struct rcu_head *rcu) |
1da177e4 | 477 | { |
989782dc | 478 | struct afs_cell *cell = container_of(rcu, struct afs_cell, rcu); |
1da177e4 | 479 | |
989782dc | 480 | _enter("%p{%s}", cell, cell->name); |
1da177e4 | 481 | |
989782dc DH |
482 | ASSERTCMP(atomic_read(&cell->usage), ==, 0); |
483 | ||
0a5143f2 | 484 | afs_put_vlserverlist(cell->net, rcu_access_pointer(cell->vl_servers)); |
989782dc DH |
485 | key_put(cell->anonymous_key); |
486 | kfree(cell); | |
487 | ||
488 | _leave(" [destroyed]"); | |
ec26815a | 489 | } |
1da177e4 | 490 | |
1da177e4 | 491 | /* |
989782dc | 492 | * Queue the cell manager. |
1da177e4 | 493 | */ |
989782dc | 494 | static void afs_queue_cell_manager(struct afs_net *net) |
1da177e4 | 495 | { |
989782dc | 496 | int outstanding = atomic_inc_return(&net->cells_outstanding); |
1da177e4 | 497 | |
989782dc | 498 | _enter("%d", outstanding); |
1da177e4 | 499 | |
989782dc DH |
500 | if (!queue_work(afs_wq, &net->cells_manager)) |
501 | afs_dec_cells_outstanding(net); | |
502 | } | |
503 | ||
504 | /* | |
505 | * Cell management timer. We have an increment on cells_outstanding that we | |
506 | * need to pass along to the work item. | |
507 | */ | |
508 | void afs_cells_timer(struct timer_list *timer) | |
509 | { | |
510 | struct afs_net *net = container_of(timer, struct afs_net, cells_timer); | |
511 | ||
512 | _enter(""); | |
513 | if (!queue_work(afs_wq, &net->cells_manager)) | |
514 | afs_dec_cells_outstanding(net); | |
515 | } | |
1da177e4 | 516 | |
8b2a464c DH |
517 | /* |
518 | * Get a reference on a cell record. | |
519 | */ | |
520 | struct afs_cell *afs_get_cell(struct afs_cell *cell) | |
521 | { | |
522 | atomic_inc(&cell->usage); | |
523 | return cell; | |
524 | } | |
525 | ||
989782dc DH |
526 | /* |
527 | * Drop a reference on a cell record. | |
528 | */ | |
529 | void afs_put_cell(struct afs_net *net, struct afs_cell *cell) | |
530 | { | |
531 | time64_t now, expire_delay; | |
1da177e4 | 532 | |
989782dc | 533 | if (!cell) |
1da177e4 | 534 | return; |
1da177e4 | 535 | |
989782dc | 536 | _enter("%s", cell->name); |
08e0e7c8 | 537 | |
989782dc DH |
538 | now = ktime_get_real_seconds(); |
539 | cell->last_inactive = now; | |
540 | expire_delay = 0; | |
d5c32c89 | 541 | if (cell->vl_servers->nr_servers) |
989782dc | 542 | expire_delay = afs_cell_gc_delay; |
1da177e4 | 543 | |
989782dc DH |
544 | if (atomic_dec_return(&cell->usage) > 1) |
545 | return; | |
1da177e4 | 546 | |
989782dc DH |
547 | /* 'cell' may now be garbage collected. */ |
548 | afs_set_cell_timer(net, expire_delay); | |
ec26815a | 549 | } |
1da177e4 | 550 | |
1da177e4 | 551 | /* |
989782dc | 552 | * Allocate a key to use as a placeholder for anonymous user security. |
1da177e4 | 553 | */ |
989782dc | 554 | static int afs_alloc_anon_key(struct afs_cell *cell) |
1da177e4 | 555 | { |
989782dc DH |
556 | struct key *key; |
557 | char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp; | |
1da177e4 | 558 | |
989782dc DH |
559 | /* Create a key to represent an anonymous user. */ |
560 | memcpy(keyname, "afs@", 4); | |
561 | dp = keyname + 4; | |
562 | cp = cell->name; | |
563 | do { | |
564 | *dp++ = tolower(*cp); | |
565 | } while (*cp++); | |
1da177e4 | 566 | |
989782dc DH |
567 | key = rxrpc_get_null_key(keyname); |
568 | if (IS_ERR(key)) | |
569 | return PTR_ERR(key); | |
1da177e4 | 570 | |
989782dc | 571 | cell->anonymous_key = key; |
1da177e4 | 572 | |
989782dc DH |
573 | _debug("anon key %p{%x}", |
574 | cell->anonymous_key, key_serial(cell->anonymous_key)); | |
575 | return 0; | |
576 | } | |
1da177e4 | 577 | |
989782dc DH |
578 | /* |
579 | * Activate a cell. | |
580 | */ | |
581 | static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell) | |
582 | { | |
6b3944e4 DH |
583 | struct hlist_node **p; |
584 | struct afs_cell *pcell; | |
989782dc DH |
585 | int ret; |
586 | ||
587 | if (!cell->anonymous_key) { | |
588 | ret = afs_alloc_anon_key(cell); | |
589 | if (ret < 0) | |
590 | return ret; | |
08e0e7c8 DH |
591 | } |
592 | ||
989782dc DH |
593 | #ifdef CONFIG_AFS_FSCACHE |
594 | cell->cache = fscache_acquire_cookie(afs_cache_netfs.primary_index, | |
595 | &afs_cell_cache_index_def, | |
402cb8dd DH |
596 | cell->name, strlen(cell->name), |
597 | NULL, 0, | |
ee1235a9 | 598 | cell, 0, true); |
989782dc | 599 | #endif |
5b86d4ff | 600 | ret = afs_proc_cell_setup(cell); |
989782dc DH |
601 | if (ret < 0) |
602 | return ret; | |
0da0b7fd DH |
603 | |
604 | mutex_lock(&net->proc_cells_lock); | |
6b3944e4 DH |
605 | for (p = &net->proc_cells.first; *p; p = &(*p)->next) { |
606 | pcell = hlist_entry(*p, struct afs_cell, proc_link); | |
607 | if (strcmp(cell->name, pcell->name) < 0) | |
608 | break; | |
609 | } | |
610 | ||
611 | cell->proc_link.pprev = p; | |
612 | cell->proc_link.next = *p; | |
613 | rcu_assign_pointer(*p, &cell->proc_link.next); | |
614 | if (cell->proc_link.next) | |
615 | cell->proc_link.next->pprev = &cell->proc_link.next; | |
616 | ||
0da0b7fd DH |
617 | afs_dynroot_mkdir(net, cell); |
618 | mutex_unlock(&net->proc_cells_lock); | |
989782dc DH |
619 | return 0; |
620 | } | |
621 | ||
622 | /* | |
623 | * Deactivate a cell. | |
624 | */ | |
625 | static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell) | |
626 | { | |
627 | _enter("%s", cell->name); | |
1da177e4 | 628 | |
5b86d4ff | 629 | afs_proc_cell_remove(cell); |
1da177e4 | 630 | |
0da0b7fd | 631 | mutex_lock(&net->proc_cells_lock); |
6b3944e4 | 632 | hlist_del_rcu(&cell->proc_link); |
0da0b7fd DH |
633 | afs_dynroot_rmdir(net, cell); |
634 | mutex_unlock(&net->proc_cells_lock); | |
1da177e4 | 635 | |
9b3f26c9 | 636 | #ifdef CONFIG_AFS_FSCACHE |
402cb8dd | 637 | fscache_relinquish_cookie(cell->cache, NULL, false); |
989782dc | 638 | cell->cache = NULL; |
1da177e4 | 639 | #endif |
1da177e4 | 640 | |
989782dc | 641 | _leave(""); |
ec26815a | 642 | } |
1da177e4 | 643 | |
1da177e4 | 644 | /* |
989782dc DH |
645 | * Manage a cell record, initialising and destroying it, maintaining its DNS |
646 | * records. | |
1da177e4 | 647 | */ |
989782dc | 648 | static void afs_manage_cell(struct work_struct *work) |
1da177e4 | 649 | { |
989782dc DH |
650 | struct afs_cell *cell = container_of(work, struct afs_cell, manager); |
651 | struct afs_net *net = cell->net; | |
652 | bool deleted; | |
653 | int ret, usage; | |
654 | ||
655 | _enter("%s", cell->name); | |
656 | ||
657 | again: | |
658 | _debug("state %u", cell->state); | |
659 | switch (cell->state) { | |
660 | case AFS_CELL_INACTIVE: | |
661 | case AFS_CELL_FAILED: | |
662 | write_seqlock(&net->cells_lock); | |
663 | usage = 1; | |
664 | deleted = atomic_try_cmpxchg_relaxed(&cell->usage, &usage, 0); | |
665 | if (deleted) | |
666 | rb_erase(&cell->net_node, &net->cells); | |
667 | write_sequnlock(&net->cells_lock); | |
668 | if (deleted) | |
669 | goto final_destruction; | |
670 | if (cell->state == AFS_CELL_FAILED) | |
671 | goto done; | |
d5c32c89 DH |
672 | smp_store_release(&cell->state, AFS_CELL_UNSET); |
673 | wake_up_var(&cell->state); | |
989782dc DH |
674 | goto again; |
675 | ||
676 | case AFS_CELL_UNSET: | |
d5c32c89 DH |
677 | smp_store_release(&cell->state, AFS_CELL_ACTIVATING); |
678 | wake_up_var(&cell->state); | |
989782dc DH |
679 | goto again; |
680 | ||
681 | case AFS_CELL_ACTIVATING: | |
682 | ret = afs_activate_cell(net, cell); | |
683 | if (ret < 0) | |
684 | goto activation_failed; | |
685 | ||
d5c32c89 DH |
686 | smp_store_release(&cell->state, AFS_CELL_ACTIVE); |
687 | wake_up_var(&cell->state); | |
989782dc DH |
688 | goto again; |
689 | ||
690 | case AFS_CELL_ACTIVE: | |
691 | if (atomic_read(&cell->usage) > 1) { | |
d5c32c89 DH |
692 | if (test_and_clear_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) { |
693 | ret = afs_update_cell(cell); | |
694 | if (ret < 0) | |
695 | cell->error = ret; | |
696 | } | |
989782dc DH |
697 | goto done; |
698 | } | |
d5c32c89 DH |
699 | smp_store_release(&cell->state, AFS_CELL_DEACTIVATING); |
700 | wake_up_var(&cell->state); | |
989782dc DH |
701 | goto again; |
702 | ||
703 | case AFS_CELL_DEACTIVATING: | |
989782dc DH |
704 | if (atomic_read(&cell->usage) > 1) |
705 | goto reverse_deactivation; | |
706 | afs_deactivate_cell(net, cell); | |
d5c32c89 DH |
707 | smp_store_release(&cell->state, AFS_CELL_INACTIVE); |
708 | wake_up_var(&cell->state); | |
989782dc DH |
709 | goto again; |
710 | ||
711 | default: | |
712 | break; | |
713 | } | |
714 | _debug("bad state %u", cell->state); | |
715 | BUG(); /* Unhandled state */ | |
716 | ||
717 | activation_failed: | |
718 | cell->error = ret; | |
719 | afs_deactivate_cell(net, cell); | |
720 | ||
d5c32c89 DH |
721 | smp_store_release(&cell->state, AFS_CELL_FAILED); /* vs error */ |
722 | wake_up_var(&cell->state); | |
989782dc DH |
723 | goto again; |
724 | ||
725 | reverse_deactivation: | |
d5c32c89 DH |
726 | smp_store_release(&cell->state, AFS_CELL_ACTIVE); |
727 | wake_up_var(&cell->state); | |
989782dc DH |
728 | _leave(" [deact->act]"); |
729 | return; | |
730 | ||
731 | done: | |
732 | _leave(" [done %u]", cell->state); | |
733 | return; | |
734 | ||
735 | final_destruction: | |
736 | call_rcu(&cell->rcu, afs_cell_destroy); | |
737 | afs_dec_cells_outstanding(net); | |
738 | _leave(" [destruct %d]", atomic_read(&net->cells_outstanding)); | |
739 | } | |
740 | ||
741 | /* | |
742 | * Manage the records of cells known to a network namespace. This includes | |
743 | * updating the DNS records and garbage collecting unused cells that were | |
744 | * automatically added. | |
745 | * | |
746 | * Note that constructed cell records may only be removed from net->cells by | |
747 | * this work item, so it is safe for this work item to stash a cursor pointing | |
748 | * into the tree and then return to caller (provided it skips cells that are | |
749 | * still under construction). | |
750 | * | |
751 | * Note also that we were given an increment on net->cells_outstanding by | |
752 | * whoever queued us that we need to deal with before returning. | |
753 | */ | |
754 | void afs_manage_cells(struct work_struct *work) | |
755 | { | |
756 | struct afs_net *net = container_of(work, struct afs_net, cells_manager); | |
757 | struct rb_node *cursor; | |
758 | time64_t now = ktime_get_real_seconds(), next_manage = TIME64_MAX; | |
759 | bool purging = !net->live; | |
1da177e4 LT |
760 | |
761 | _enter(""); | |
762 | ||
989782dc DH |
763 | /* Trawl the cell database looking for cells that have expired from |
764 | * lack of use and cells whose DNS results have expired and dispatch | |
765 | * their managers. | |
766 | */ | |
767 | read_seqlock_excl(&net->cells_lock); | |
1da177e4 | 768 | |
989782dc DH |
769 | for (cursor = rb_first(&net->cells); cursor; cursor = rb_next(cursor)) { |
770 | struct afs_cell *cell = | |
771 | rb_entry(cursor, struct afs_cell, net_node); | |
772 | unsigned usage; | |
773 | bool sched_cell = false; | |
08e0e7c8 | 774 | |
989782dc DH |
775 | usage = atomic_read(&cell->usage); |
776 | _debug("manage %s %u", cell->name, usage); | |
777 | ||
778 | ASSERTCMP(usage, >=, 1); | |
779 | ||
780 | if (purging) { | |
781 | if (test_and_clear_bit(AFS_CELL_FL_NO_GC, &cell->flags)) | |
782 | usage = atomic_dec_return(&cell->usage); | |
783 | ASSERTCMP(usage, ==, 1); | |
784 | } | |
1da177e4 | 785 | |
989782dc | 786 | if (usage == 1) { |
d5c32c89 | 787 | struct afs_vlserver_list *vllist; |
989782dc | 788 | time64_t expire_at = cell->last_inactive; |
1da177e4 | 789 | |
d5c32c89 DH |
790 | read_lock(&cell->vl_servers_lock); |
791 | vllist = rcu_dereference_protected( | |
792 | cell->vl_servers, | |
793 | lockdep_is_held(&cell->vl_servers_lock)); | |
794 | if (vllist->nr_servers > 0) | |
989782dc | 795 | expire_at += afs_cell_gc_delay; |
d5c32c89 | 796 | read_unlock(&cell->vl_servers_lock); |
989782dc DH |
797 | if (purging || expire_at <= now) |
798 | sched_cell = true; | |
799 | else if (expire_at < next_manage) | |
800 | next_manage = expire_at; | |
1da177e4 LT |
801 | } |
802 | ||
989782dc | 803 | if (!purging) { |
d5c32c89 | 804 | if (test_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) |
989782dc | 805 | sched_cell = true; |
989782dc DH |
806 | } |
807 | ||
808 | if (sched_cell) | |
809 | queue_work(afs_wq, &cell->manager); | |
810 | } | |
811 | ||
812 | read_sequnlock_excl(&net->cells_lock); | |
1da177e4 | 813 | |
989782dc DH |
814 | /* Update the timer on the way out. We have to pass an increment on |
815 | * cells_outstanding in the namespace that we are in to the timer or | |
816 | * the work scheduler. | |
817 | */ | |
818 | if (!purging && next_manage < TIME64_MAX) { | |
819 | now = ktime_get_real_seconds(); | |
1da177e4 | 820 | |
989782dc DH |
821 | if (next_manage - now <= 0) { |
822 | if (queue_work(afs_wq, &net->cells_manager)) | |
823 | atomic_inc(&net->cells_outstanding); | |
824 | } else { | |
825 | afs_set_cell_timer(net, next_manage - now); | |
1da177e4 LT |
826 | } |
827 | } | |
828 | ||
989782dc DH |
829 | afs_dec_cells_outstanding(net); |
830 | _leave(" [%d]", atomic_read(&net->cells_outstanding)); | |
831 | } | |
832 | ||
833 | /* | |
834 | * Purge in-memory cell database. | |
835 | */ | |
836 | void afs_cell_purge(struct afs_net *net) | |
837 | { | |
838 | struct afs_cell *ws; | |
839 | ||
840 | _enter(""); | |
841 | ||
842 | write_seqlock(&net->cells_lock); | |
1588def9 DH |
843 | ws = rcu_access_pointer(net->ws_cell); |
844 | RCU_INIT_POINTER(net->ws_cell, NULL); | |
989782dc DH |
845 | write_sequnlock(&net->cells_lock); |
846 | afs_put_cell(net, ws); | |
847 | ||
848 | _debug("del timer"); | |
849 | if (del_timer_sync(&net->cells_timer)) | |
850 | atomic_dec(&net->cells_outstanding); | |
851 | ||
852 | _debug("kick mgr"); | |
853 | afs_queue_cell_manager(net); | |
854 | ||
855 | _debug("wait"); | |
ab1fbe32 PZ |
856 | wait_var_event(&net->cells_outstanding, |
857 | !atomic_read(&net->cells_outstanding)); | |
1da177e4 | 858 | _leave(""); |
ec26815a | 859 | } |