Commit | Line | Data |
---|---|---|
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; | |
dca54a7b | 21 | static atomic_t cell_debug_id; |
989782dc | 22 | |
286377f6 | 23 | static void afs_queue_cell_manager(struct afs_net *); |
88c853c3 | 24 | static void afs_manage_cell_work(struct work_struct *); |
989782dc DH |
25 | |
26 | static void afs_dec_cells_outstanding(struct afs_net *net) | |
27 | { | |
28 | if (atomic_dec_and_test(&net->cells_outstanding)) | |
ab1fbe32 | 29 | wake_up_var(&net->cells_outstanding); |
989782dc DH |
30 | } |
31 | ||
1da177e4 | 32 | /* |
989782dc DH |
33 | * Set the cell timer to fire after a given delay, assuming it's not already |
34 | * set for an earlier time. | |
1da177e4 | 35 | */ |
989782dc | 36 | static void afs_set_cell_timer(struct afs_net *net, time64_t delay) |
1da177e4 | 37 | { |
989782dc DH |
38 | if (net->live) { |
39 | atomic_inc(&net->cells_outstanding); | |
40 | if (timer_reduce(&net->cells_timer, jiffies + delay * HZ)) | |
41 | afs_dec_cells_outstanding(net); | |
286377f6 DH |
42 | } else { |
43 | afs_queue_cell_manager(net); | |
989782dc DH |
44 | } |
45 | } | |
46 | ||
47 | /* | |
92e3cc91 DH |
48 | * Look up and get an activation reference on a cell record. The caller must |
49 | * hold net->cells_lock at least read-locked. | |
989782dc | 50 | */ |
92e3cc91 | 51 | static struct afs_cell *afs_find_cell_locked(struct afs_net *net, |
dca54a7b DH |
52 | const char *name, unsigned int namesz, |
53 | enum afs_cell_trace reason) | |
989782dc DH |
54 | { |
55 | struct afs_cell *cell = NULL; | |
56 | struct rb_node *p; | |
92e3cc91 | 57 | int n; |
989782dc DH |
58 | |
59 | _enter("%*.*s", namesz, namesz, name); | |
60 | ||
61 | if (name && namesz == 0) | |
62 | return ERR_PTR(-EINVAL); | |
63 | if (namesz > AFS_MAXCELLNAME) | |
64 | return ERR_PTR(-ENAMETOOLONG); | |
65 | ||
92e3cc91 DH |
66 | if (!name) { |
67 | cell = net->ws_cell; | |
68 | if (!cell) | |
69 | return ERR_PTR(-EDESTADDRREQ); | |
88c853c3 | 70 | goto found; |
92e3cc91 | 71 | } |
989782dc | 72 | |
92e3cc91 DH |
73 | p = net->cells.rb_node; |
74 | while (p) { | |
75 | cell = rb_entry(p, struct afs_cell, net_node); | |
1da177e4 | 76 | |
92e3cc91 DH |
77 | n = strncasecmp(cell->name, name, |
78 | min_t(size_t, cell->name_len, namesz)); | |
79 | if (n == 0) | |
80 | n = cell->name_len - namesz; | |
81 | if (n < 0) | |
82 | p = p->rb_left; | |
83 | else if (n > 0) | |
84 | p = p->rb_right; | |
85 | else | |
86 | goto found; | |
87 | } | |
88 | ||
89 | return ERR_PTR(-ENOENT); | |
1da177e4 | 90 | |
92e3cc91 | 91 | found: |
dca54a7b | 92 | return afs_use_cell(cell, reason); |
92e3cc91 | 93 | } |
a5fb8e6c | 94 | |
88c853c3 DH |
95 | /* |
96 | * Look up and get an activation reference on a cell record. | |
97 | */ | |
92e3cc91 | 98 | struct afs_cell *afs_find_cell(struct afs_net *net, |
dca54a7b DH |
99 | const char *name, unsigned int namesz, |
100 | enum afs_cell_trace reason) | |
92e3cc91 DH |
101 | { |
102 | struct afs_cell *cell; | |
103 | ||
104 | down_read(&net->cells_lock); | |
dca54a7b | 105 | cell = afs_find_cell_locked(net, name, namesz, reason); |
92e3cc91 DH |
106 | up_read(&net->cells_lock); |
107 | return cell; | |
989782dc DH |
108 | } |
109 | ||
110 | /* | |
111 | * Set up a cell record and fill in its name, VL server address list and | |
112 | * allocate an anonymous key | |
113 | */ | |
114 | static struct afs_cell *afs_alloc_cell(struct afs_net *net, | |
115 | const char *name, unsigned int namelen, | |
0a5143f2 | 116 | const char *addresses) |
989782dc | 117 | { |
ca1cbbdc | 118 | struct afs_vlserver_list *vllist; |
989782dc DH |
119 | struct afs_cell *cell; |
120 | int i, ret; | |
121 | ||
122 | ASSERT(name); | |
123 | if (namelen == 0) | |
124 | return ERR_PTR(-EINVAL); | |
07567a55 WL |
125 | if (namelen > AFS_MAXCELLNAME) { |
126 | _leave(" = -ENAMETOOLONG"); | |
00d3b7a4 | 127 | return ERR_PTR(-ENAMETOOLONG); |
07567a55 | 128 | } |
a45ea48e DH |
129 | |
130 | /* Prohibit cell names that contain unprintable chars, '/' and '@' or | |
131 | * that begin with a dot. This also precludes "@cell". | |
132 | */ | |
133 | if (name[0] == '.') | |
37ab6368 | 134 | return ERR_PTR(-EINVAL); |
a45ea48e DH |
135 | for (i = 0; i < namelen; i++) { |
136 | char ch = name[i]; | |
137 | if (!isprint(ch) || ch == '/' || ch == '@') | |
138 | return ERR_PTR(-EINVAL); | |
139 | } | |
00d3b7a4 | 140 | |
0a5143f2 | 141 | _enter("%*.*s,%s", namelen, namelen, name, addresses); |
989782dc DH |
142 | |
143 | cell = kzalloc(sizeof(struct afs_cell), GFP_KERNEL); | |
1da177e4 LT |
144 | if (!cell) { |
145 | _leave(" = -ENOMEM"); | |
08e0e7c8 | 146 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
147 | } |
148 | ||
719fdd32 DH |
149 | cell->name = kmalloc(namelen + 1, GFP_KERNEL); |
150 | if (!cell->name) { | |
151 | kfree(cell); | |
152 | return ERR_PTR(-ENOMEM); | |
153 | } | |
154 | ||
f044c884 | 155 | cell->net = net; |
989782dc DH |
156 | cell->name_len = namelen; |
157 | for (i = 0; i < namelen; i++) | |
158 | cell->name[i] = tolower(name[i]); | |
719fdd32 | 159 | cell->name[i] = 0; |
989782dc | 160 | |
c56f9ec8 | 161 | refcount_set(&cell->ref, 1); |
88c853c3 DH |
162 | atomic_set(&cell->active, 0); |
163 | INIT_WORK(&cell->manager, afs_manage_cell_work); | |
32222f09 | 164 | init_rwsem(&cell->vs_lock); |
20325960 DH |
165 | cell->volumes = RB_ROOT; |
166 | INIT_HLIST_HEAD(&cell->proc_volumes); | |
167 | seqlock_init(&cell->volume_lock); | |
168 | cell->fs_servers = RB_ROOT; | |
169 | seqlock_init(&cell->fs_lock); | |
0a5143f2 | 170 | rwlock_init(&cell->vl_servers_lock); |
8a070a96 | 171 | cell->flags = (1 << AFS_CELL_FL_CHECK_ALIAS); |
4d9df986 | 172 | |
ca1cbbdc DH |
173 | /* Provide a VL server list, filling it in if we were given a list of |
174 | * addresses to use. | |
989782dc | 175 | */ |
0a5143f2 | 176 | if (addresses) { |
0a5143f2 DH |
177 | vllist = afs_parse_text_addrs(net, |
178 | addresses, strlen(addresses), ':', | |
179 | VL_SERVICE, AFS_VL_PORT); | |
180 | if (IS_ERR(vllist)) { | |
181 | ret = PTR_ERR(vllist); | |
8b2a464c DH |
182 | goto parse_failed; |
183 | } | |
00d3b7a4 | 184 | |
d5c32c89 DH |
185 | vllist->source = DNS_RECORD_FROM_CONFIG; |
186 | vllist->status = DNS_LOOKUP_NOT_DONE; | |
989782dc | 187 | cell->dns_expiry = TIME64_MAX; |
ded2f4c5 | 188 | } else { |
ca1cbbdc DH |
189 | ret = -ENOMEM; |
190 | vllist = afs_alloc_vlserver_list(0); | |
191 | if (!vllist) | |
192 | goto error; | |
d5c32c89 DH |
193 | vllist->source = DNS_RECORD_UNAVAILABLE; |
194 | vllist->status = DNS_LOOKUP_NOT_DONE; | |
ded2f4c5 | 195 | cell->dns_expiry = ktime_get_real_seconds(); |
00d3b7a4 | 196 | } |
00d3b7a4 | 197 | |
ca1cbbdc DH |
198 | rcu_assign_pointer(cell->vl_servers, vllist); |
199 | ||
d5c32c89 DH |
200 | cell->dns_source = vllist->source; |
201 | cell->dns_status = vllist->status; | |
202 | smp_store_release(&cell->dns_lookup_count, 1); /* vs source/status */ | |
88c853c3 | 203 | atomic_inc(&net->cells_outstanding); |
dca54a7b DH |
204 | cell->debug_id = atomic_inc_return(&cell_debug_id); |
205 | trace_afs_cell(cell->debug_id, 1, 0, afs_cell_trace_alloc); | |
d5c32c89 | 206 | |
00d3b7a4 DH |
207 | _leave(" = %p", cell); |
208 | return cell; | |
209 | ||
8b2a464c DH |
210 | parse_failed: |
211 | if (ret == -EINVAL) | |
212 | printk(KERN_ERR "kAFS: bad VL server IP address\n"); | |
ca1cbbdc | 213 | error: |
719fdd32 | 214 | kfree(cell->name); |
00d3b7a4 DH |
215 | kfree(cell); |
216 | _leave(" = %d", ret); | |
217 | return ERR_PTR(ret); | |
218 | } | |
1da177e4 | 219 | |
00d3b7a4 | 220 | /* |
989782dc | 221 | * afs_lookup_cell - Look up or create a cell record. |
f044c884 | 222 | * @net: The network namespace |
989782dc DH |
223 | * @name: The name of the cell. |
224 | * @namesz: The strlen of the cell name. | |
225 | * @vllist: A colon/comma separated list of numeric IP addresses or NULL. | |
226 | * @excl: T if an error should be given if the cell name already exists. | |
227 | * | |
228 | * Look up a cell record by name and query the DNS for VL server addresses if | |
229 | * needed. Note that that actual DNS query is punted off to the manager thread | |
230 | * so that this function can return immediately if interrupted whilst allowing | |
231 | * cell records to be shared even if not yet fully constructed. | |
00d3b7a4 | 232 | */ |
989782dc DH |
233 | struct afs_cell *afs_lookup_cell(struct afs_net *net, |
234 | const char *name, unsigned int namesz, | |
235 | const char *vllist, bool excl) | |
00d3b7a4 | 236 | { |
989782dc DH |
237 | struct afs_cell *cell, *candidate, *cursor; |
238 | struct rb_node *parent, **pp; | |
d5c32c89 | 239 | enum afs_cell_state state; |
989782dc DH |
240 | int ret, n; |
241 | ||
242 | _enter("%s,%s", name, vllist); | |
243 | ||
244 | if (!excl) { | |
dca54a7b | 245 | cell = afs_find_cell(net, name, namesz, afs_cell_trace_use_lookup); |
68327951 | 246 | if (!IS_ERR(cell)) |
989782dc | 247 | goto wait_for_cell; |
989782dc | 248 | } |
00d3b7a4 | 249 | |
989782dc DH |
250 | /* Assume we're probably going to create a cell and preallocate and |
251 | * mostly set up a candidate record. We can then use this to stash the | |
252 | * name, the net namespace and VL server addresses. | |
253 | * | |
254 | * We also want to do this before we hold any locks as it may involve | |
255 | * upcalling to userspace to make DNS queries. | |
256 | */ | |
257 | candidate = afs_alloc_cell(net, name, namesz, vllist); | |
258 | if (IS_ERR(candidate)) { | |
259 | _leave(" = %ld", PTR_ERR(candidate)); | |
260 | return candidate; | |
5214b729 | 261 | } |
5214b729 | 262 | |
989782dc DH |
263 | /* Find the insertion point and check to see if someone else added a |
264 | * cell whilst we were allocating. | |
265 | */ | |
92e3cc91 | 266 | down_write(&net->cells_lock); |
989782dc DH |
267 | |
268 | pp = &net->cells.rb_node; | |
269 | parent = NULL; | |
270 | while (*pp) { | |
271 | parent = *pp; | |
272 | cursor = rb_entry(parent, struct afs_cell, net_node); | |
273 | ||
274 | n = strncasecmp(cursor->name, name, | |
275 | min_t(size_t, cursor->name_len, namesz)); | |
276 | if (n == 0) | |
277 | n = cursor->name_len - namesz; | |
278 | if (n < 0) | |
279 | pp = &(*pp)->rb_left; | |
280 | else if (n > 0) | |
281 | pp = &(*pp)->rb_right; | |
282 | else | |
283 | goto cell_already_exists; | |
00d3b7a4 DH |
284 | } |
285 | ||
989782dc DH |
286 | cell = candidate; |
287 | candidate = NULL; | |
88c853c3 | 288 | atomic_set(&cell->active, 2); |
c56f9ec8 | 289 | trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), 2, afs_cell_trace_insert); |
989782dc DH |
290 | rb_link_node_rcu(&cell->net_node, parent, pp); |
291 | rb_insert_color(&cell->net_node, &net->cells); | |
92e3cc91 | 292 | up_write(&net->cells_lock); |
1da177e4 | 293 | |
dca54a7b | 294 | afs_queue_cell(cell, afs_cell_trace_get_queue_new); |
1da177e4 | 295 | |
989782dc | 296 | wait_for_cell: |
c56f9ec8 | 297 | trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), atomic_read(&cell->active), |
dca54a7b | 298 | afs_cell_trace_wait); |
989782dc | 299 | _debug("wait_for_cell"); |
d5c32c89 DH |
300 | wait_var_event(&cell->state, |
301 | ({ | |
302 | state = smp_load_acquire(&cell->state); /* vs error */ | |
1d0e850a | 303 | state == AFS_CELL_ACTIVE || state == AFS_CELL_REMOVED; |
d5c32c89 DH |
304 | })); |
305 | ||
306 | /* Check the state obtained from the wait check. */ | |
1d0e850a | 307 | if (state == AFS_CELL_REMOVED) { |
989782dc DH |
308 | ret = cell->error; |
309 | goto error; | |
989782dc | 310 | } |
1da177e4 | 311 | |
989782dc | 312 | _leave(" = %p [cell]", cell); |
08e0e7c8 | 313 | return cell; |
1da177e4 | 314 | |
989782dc DH |
315 | cell_already_exists: |
316 | _debug("cell exists"); | |
317 | cell = cursor; | |
318 | if (excl) { | |
319 | ret = -EEXIST; | |
320 | } else { | |
dca54a7b | 321 | afs_use_cell(cursor, afs_cell_trace_use_lookup); |
989782dc DH |
322 | ret = 0; |
323 | } | |
92e3cc91 | 324 | up_write(&net->cells_lock); |
88c853c3 | 325 | if (candidate) |
dca54a7b | 326 | afs_put_cell(candidate, afs_cell_trace_put_candidate); |
989782dc DH |
327 | if (ret == 0) |
328 | goto wait_for_cell; | |
8b2a464c | 329 | goto error_noput; |
ec26815a | 330 | error: |
dca54a7b | 331 | afs_unuse_cell(net, cell, afs_cell_trace_unuse_lookup); |
8b2a464c | 332 | error_noput: |
989782dc | 333 | _leave(" = %d [error]", ret); |
08e0e7c8 | 334 | return ERR_PTR(ret); |
ec26815a | 335 | } |
1da177e4 | 336 | |
1da177e4 | 337 | /* |
08e0e7c8 DH |
338 | * set the root cell information |
339 | * - can be called with a module parameter string | |
340 | * - can be called from a write to /proc/fs/afs/rootcell | |
1da177e4 | 341 | */ |
989782dc | 342 | int afs_cell_init(struct afs_net *net, const char *rootcell) |
1da177e4 LT |
343 | { |
344 | struct afs_cell *old_root, *new_root; | |
989782dc DH |
345 | const char *cp, *vllist; |
346 | size_t len; | |
1da177e4 LT |
347 | |
348 | _enter(""); | |
349 | ||
350 | if (!rootcell) { | |
351 | /* module is loaded with no parameters, or built statically. | |
352 | * - in the future we might initialize cell DB here. | |
353 | */ | |
08e0e7c8 | 354 | _leave(" = 0 [no root]"); |
1da177e4 LT |
355 | return 0; |
356 | } | |
357 | ||
358 | cp = strchr(rootcell, ':'); | |
989782dc | 359 | if (!cp) { |
07567a55 | 360 | _debug("kAFS: no VL server IP addresses specified"); |
989782dc DH |
361 | vllist = NULL; |
362 | len = strlen(rootcell); | |
363 | } else { | |
364 | vllist = cp + 1; | |
365 | len = cp - rootcell; | |
366 | } | |
1da177e4 LT |
367 | |
368 | /* allocate a cell record for the root cell */ | |
989782dc | 369 | new_root = afs_lookup_cell(net, rootcell, len, vllist, false); |
08e0e7c8 DH |
370 | if (IS_ERR(new_root)) { |
371 | _leave(" = %ld", PTR_ERR(new_root)); | |
372 | return PTR_ERR(new_root); | |
1da177e4 LT |
373 | } |
374 | ||
17814aef | 375 | if (!test_and_set_bit(AFS_CELL_FL_NO_GC, &new_root->flags)) |
dca54a7b | 376 | afs_use_cell(new_root, afs_cell_trace_use_pin); |
989782dc | 377 | |
08e0e7c8 | 378 | /* install the new cell */ |
92e3cc91 | 379 | down_write(&net->cells_lock); |
dca54a7b | 380 | afs_see_cell(new_root, afs_cell_trace_see_ws); |
92e3cc91 DH |
381 | old_root = net->ws_cell; |
382 | net->ws_cell = new_root; | |
383 | up_write(&net->cells_lock); | |
1da177e4 | 384 | |
dca54a7b | 385 | afs_unuse_cell(net, old_root, afs_cell_trace_unuse_ws); |
08e0e7c8 DH |
386 | _leave(" = 0"); |
387 | return 0; | |
ec26815a | 388 | } |
1da177e4 | 389 | |
1da177e4 | 390 | /* |
989782dc | 391 | * Update a cell's VL server address list from the DNS. |
1da177e4 | 392 | */ |
d5c32c89 | 393 | static int afs_update_cell(struct afs_cell *cell) |
1da177e4 | 394 | { |
d5c32c89 | 395 | struct afs_vlserver_list *vllist, *old = NULL, *p; |
ded2f4c5 DH |
396 | unsigned int min_ttl = READ_ONCE(afs_cell_min_ttl); |
397 | unsigned int max_ttl = READ_ONCE(afs_cell_max_ttl); | |
398 | time64_t now, expiry = 0; | |
d5c32c89 | 399 | int ret = 0; |
1da177e4 | 400 | |
989782dc DH |
401 | _enter("%s", cell->name); |
402 | ||
0a5143f2 | 403 | vllist = afs_dns_query(cell, &expiry); |
d5c32c89 DH |
404 | if (IS_ERR(vllist)) { |
405 | ret = PTR_ERR(vllist); | |
406 | ||
407 | _debug("%s: fail %d", cell->name, ret); | |
408 | if (ret == -ENOMEM) | |
409 | goto out_wake; | |
410 | ||
d5c32c89 | 411 | vllist = afs_alloc_vlserver_list(0); |
a9e01ac8 DH |
412 | if (!vllist) { |
413 | if (ret >= 0) | |
414 | ret = -ENOMEM; | |
d5c32c89 | 415 | goto out_wake; |
a9e01ac8 | 416 | } |
d5c32c89 DH |
417 | |
418 | switch (ret) { | |
419 | case -ENODATA: | |
420 | case -EDESTADDRREQ: | |
421 | vllist->status = DNS_LOOKUP_GOT_NOT_FOUND; | |
422 | break; | |
423 | case -EAGAIN: | |
424 | case -ECONNREFUSED: | |
425 | vllist->status = DNS_LOOKUP_GOT_TEMP_FAILURE; | |
426 | break; | |
427 | default: | |
428 | vllist->status = DNS_LOOKUP_GOT_LOCAL_FAILURE; | |
429 | break; | |
430 | } | |
431 | } | |
432 | ||
433 | _debug("%s: got list %d %d", cell->name, vllist->source, vllist->status); | |
434 | cell->dns_status = vllist->status; | |
ded2f4c5 DH |
435 | |
436 | now = ktime_get_real_seconds(); | |
437 | if (min_ttl > max_ttl) | |
438 | max_ttl = min_ttl; | |
439 | if (expiry < now + min_ttl) | |
440 | expiry = now + min_ttl; | |
441 | else if (expiry > now + max_ttl) | |
442 | expiry = now + max_ttl; | |
443 | ||
d5c32c89 DH |
444 | _debug("%s: status %d", cell->name, vllist->status); |
445 | if (vllist->source == DNS_RECORD_UNAVAILABLE) { | |
446 | switch (vllist->status) { | |
447 | case DNS_LOOKUP_GOT_NOT_FOUND: | |
ded2f4c5 DH |
448 | /* The DNS said that the cell does not exist or there |
449 | * weren't any addresses to be had. | |
450 | */ | |
ded2f4c5 | 451 | cell->dns_expiry = expiry; |
8b2a464c | 452 | break; |
989782dc | 453 | |
d5c32c89 DH |
454 | case DNS_LOOKUP_BAD: |
455 | case DNS_LOOKUP_GOT_LOCAL_FAILURE: | |
456 | case DNS_LOOKUP_GOT_TEMP_FAILURE: | |
457 | case DNS_LOOKUP_GOT_NS_FAILURE: | |
8b2a464c | 458 | default: |
ded2f4c5 | 459 | cell->dns_expiry = now + 10; |
8b2a464c DH |
460 | break; |
461 | } | |
8b2a464c | 462 | } else { |
8b2a464c | 463 | cell->dns_expiry = expiry; |
8b2a464c | 464 | } |
bec5eb61 | 465 | |
d5c32c89 DH |
466 | /* Replace the VL server list if the new record has servers or the old |
467 | * record doesn't. | |
468 | */ | |
469 | write_lock(&cell->vl_servers_lock); | |
470 | p = rcu_dereference_protected(cell->vl_servers, true); | |
471 | if (vllist->nr_servers > 0 || p->nr_servers == 0) { | |
472 | rcu_assign_pointer(cell->vl_servers, vllist); | |
473 | cell->dns_source = vllist->source; | |
474 | old = p; | |
475 | } | |
476 | write_unlock(&cell->vl_servers_lock); | |
477 | afs_put_vlserverlist(cell->net, old); | |
bec5eb61 | 478 | |
d5c32c89 DH |
479 | out_wake: |
480 | smp_store_release(&cell->dns_lookup_count, | |
481 | cell->dns_lookup_count + 1); /* vs source/status */ | |
482 | wake_up_var(&cell->dns_lookup_count); | |
483 | _leave(" = %d", ret); | |
484 | return ret; | |
ec26815a | 485 | } |
1da177e4 | 486 | |
1da177e4 | 487 | /* |
989782dc | 488 | * Destroy a cell record |
1da177e4 | 489 | */ |
989782dc | 490 | static void afs_cell_destroy(struct rcu_head *rcu) |
1da177e4 | 491 | { |
989782dc | 492 | struct afs_cell *cell = container_of(rcu, struct afs_cell, rcu); |
88c853c3 | 493 | struct afs_net *net = cell->net; |
c56f9ec8 | 494 | int r; |
1da177e4 | 495 | |
989782dc | 496 | _enter("%p{%s}", cell, cell->name); |
1da177e4 | 497 | |
c56f9ec8 DH |
498 | r = refcount_read(&cell->ref); |
499 | ASSERTCMP(r, ==, 0); | |
500 | trace_afs_cell(cell->debug_id, r, atomic_read(&cell->active), afs_cell_trace_free); | |
989782dc | 501 | |
88c853c3 | 502 | afs_put_vlserverlist(net, rcu_access_pointer(cell->vl_servers)); |
dca54a7b | 503 | afs_unuse_cell(net, cell->alias_of, afs_cell_trace_unuse_alias); |
989782dc | 504 | key_put(cell->anonymous_key); |
719fdd32 | 505 | kfree(cell->name); |
989782dc DH |
506 | kfree(cell); |
507 | ||
88c853c3 | 508 | afs_dec_cells_outstanding(net); |
989782dc | 509 | _leave(" [destroyed]"); |
ec26815a | 510 | } |
1da177e4 | 511 | |
1da177e4 | 512 | /* |
989782dc | 513 | * Queue the cell manager. |
1da177e4 | 514 | */ |
989782dc | 515 | static void afs_queue_cell_manager(struct afs_net *net) |
1da177e4 | 516 | { |
989782dc | 517 | int outstanding = atomic_inc_return(&net->cells_outstanding); |
1da177e4 | 518 | |
989782dc | 519 | _enter("%d", outstanding); |
1da177e4 | 520 | |
989782dc DH |
521 | if (!queue_work(afs_wq, &net->cells_manager)) |
522 | afs_dec_cells_outstanding(net); | |
523 | } | |
524 | ||
525 | /* | |
526 | * Cell management timer. We have an increment on cells_outstanding that we | |
527 | * need to pass along to the work item. | |
528 | */ | |
529 | void afs_cells_timer(struct timer_list *timer) | |
530 | { | |
531 | struct afs_net *net = container_of(timer, struct afs_net, cells_timer); | |
532 | ||
533 | _enter(""); | |
534 | if (!queue_work(afs_wq, &net->cells_manager)) | |
535 | afs_dec_cells_outstanding(net); | |
536 | } | |
1da177e4 | 537 | |
8b2a464c DH |
538 | /* |
539 | * Get a reference on a cell record. | |
540 | */ | |
dca54a7b | 541 | struct afs_cell *afs_get_cell(struct afs_cell *cell, enum afs_cell_trace reason) |
8b2a464c | 542 | { |
c56f9ec8 | 543 | int r; |
dca54a7b | 544 | |
c56f9ec8 DH |
545 | __refcount_inc(&cell->ref, &r); |
546 | trace_afs_cell(cell->debug_id, r + 1, atomic_read(&cell->active), reason); | |
8b2a464c DH |
547 | return cell; |
548 | } | |
549 | ||
989782dc DH |
550 | /* |
551 | * Drop a reference on a cell record. | |
552 | */ | |
dca54a7b | 553 | void afs_put_cell(struct afs_cell *cell, enum afs_cell_trace reason) |
88c853c3 DH |
554 | { |
555 | if (cell) { | |
dca54a7b | 556 | unsigned int debug_id = cell->debug_id; |
c56f9ec8 DH |
557 | unsigned int a; |
558 | bool zero; | |
559 | int r; | |
88c853c3 | 560 | |
dca54a7b | 561 | a = atomic_read(&cell->active); |
c56f9ec8 DH |
562 | zero = __refcount_dec_and_test(&cell->ref, &r); |
563 | trace_afs_cell(debug_id, r - 1, a, reason); | |
564 | if (zero) { | |
88c853c3 DH |
565 | a = atomic_read(&cell->active); |
566 | WARN(a != 0, "Cell active count %u > 0\n", a); | |
567 | call_rcu(&cell->rcu, afs_cell_destroy); | |
568 | } | |
569 | } | |
570 | } | |
571 | ||
572 | /* | |
573 | * Note a cell becoming more active. | |
574 | */ | |
dca54a7b | 575 | struct afs_cell *afs_use_cell(struct afs_cell *cell, enum afs_cell_trace reason) |
88c853c3 | 576 | { |
c56f9ec8 | 577 | int r, a; |
88c853c3 | 578 | |
c56f9ec8 DH |
579 | r = refcount_read(&cell->ref); |
580 | WARN_ON(r == 0); | |
dca54a7b | 581 | a = atomic_inc_return(&cell->active); |
c56f9ec8 | 582 | trace_afs_cell(cell->debug_id, r, a, reason); |
88c853c3 DH |
583 | return cell; |
584 | } | |
585 | ||
586 | /* | |
587 | * Record a cell becoming less active. When the active counter reaches 1, it | |
588 | * is scheduled for destruction, but may get reactivated. | |
589 | */ | |
dca54a7b | 590 | void afs_unuse_cell(struct afs_net *net, struct afs_cell *cell, enum afs_cell_trace reason) |
989782dc | 591 | { |
acc080d1 | 592 | unsigned int debug_id; |
989782dc | 593 | time64_t now, expire_delay; |
c56f9ec8 | 594 | int r, a; |
1da177e4 | 595 | |
989782dc | 596 | if (!cell) |
1da177e4 | 597 | return; |
1da177e4 | 598 | |
989782dc | 599 | _enter("%s", cell->name); |
08e0e7c8 | 600 | |
989782dc DH |
601 | now = ktime_get_real_seconds(); |
602 | cell->last_inactive = now; | |
603 | expire_delay = 0; | |
d5c32c89 | 604 | if (cell->vl_servers->nr_servers) |
989782dc | 605 | expire_delay = afs_cell_gc_delay; |
1da177e4 | 606 | |
acc080d1 | 607 | debug_id = cell->debug_id; |
c56f9ec8 | 608 | r = refcount_read(&cell->ref); |
88c853c3 | 609 | a = atomic_dec_return(&cell->active); |
c56f9ec8 | 610 | trace_afs_cell(debug_id, r, a, reason); |
88c853c3 DH |
611 | WARN_ON(a == 0); |
612 | if (a == 1) | |
613 | /* 'cell' may now be garbage collected. */ | |
614 | afs_set_cell_timer(net, expire_delay); | |
615 | } | |
1da177e4 | 616 | |
dca54a7b DH |
617 | /* |
618 | * Note that a cell has been seen. | |
619 | */ | |
620 | void afs_see_cell(struct afs_cell *cell, enum afs_cell_trace reason) | |
621 | { | |
c56f9ec8 | 622 | int r, a; |
dca54a7b | 623 | |
c56f9ec8 | 624 | r = refcount_read(&cell->ref); |
dca54a7b | 625 | a = atomic_read(&cell->active); |
c56f9ec8 | 626 | trace_afs_cell(cell->debug_id, r, a, reason); |
dca54a7b DH |
627 | } |
628 | ||
88c853c3 DH |
629 | /* |
630 | * Queue a cell for management, giving the workqueue a ref to hold. | |
631 | */ | |
dca54a7b | 632 | void afs_queue_cell(struct afs_cell *cell, enum afs_cell_trace reason) |
88c853c3 | 633 | { |
dca54a7b | 634 | afs_get_cell(cell, reason); |
88c853c3 | 635 | if (!queue_work(afs_wq, &cell->manager)) |
dca54a7b | 636 | afs_put_cell(cell, afs_cell_trace_put_queue_fail); |
ec26815a | 637 | } |
1da177e4 | 638 | |
1da177e4 | 639 | /* |
989782dc | 640 | * Allocate a key to use as a placeholder for anonymous user security. |
1da177e4 | 641 | */ |
989782dc | 642 | static int afs_alloc_anon_key(struct afs_cell *cell) |
1da177e4 | 643 | { |
989782dc DH |
644 | struct key *key; |
645 | char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp; | |
1da177e4 | 646 | |
989782dc DH |
647 | /* Create a key to represent an anonymous user. */ |
648 | memcpy(keyname, "afs@", 4); | |
649 | dp = keyname + 4; | |
650 | cp = cell->name; | |
651 | do { | |
652 | *dp++ = tolower(*cp); | |
653 | } while (*cp++); | |
1da177e4 | 654 | |
989782dc DH |
655 | key = rxrpc_get_null_key(keyname); |
656 | if (IS_ERR(key)) | |
657 | return PTR_ERR(key); | |
1da177e4 | 658 | |
989782dc | 659 | cell->anonymous_key = key; |
1da177e4 | 660 | |
989782dc DH |
661 | _debug("anon key %p{%x}", |
662 | cell->anonymous_key, key_serial(cell->anonymous_key)); | |
663 | return 0; | |
664 | } | |
1da177e4 | 665 | |
989782dc DH |
666 | /* |
667 | * Activate a cell. | |
668 | */ | |
669 | static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell) | |
670 | { | |
6b3944e4 DH |
671 | struct hlist_node **p; |
672 | struct afs_cell *pcell; | |
989782dc DH |
673 | int ret; |
674 | ||
675 | if (!cell->anonymous_key) { | |
676 | ret = afs_alloc_anon_key(cell); | |
677 | if (ret < 0) | |
678 | return ret; | |
08e0e7c8 DH |
679 | } |
680 | ||
5b86d4ff | 681 | ret = afs_proc_cell_setup(cell); |
989782dc DH |
682 | if (ret < 0) |
683 | return ret; | |
0da0b7fd DH |
684 | |
685 | mutex_lock(&net->proc_cells_lock); | |
6b3944e4 DH |
686 | for (p = &net->proc_cells.first; *p; p = &(*p)->next) { |
687 | pcell = hlist_entry(*p, struct afs_cell, proc_link); | |
688 | if (strcmp(cell->name, pcell->name) < 0) | |
689 | break; | |
690 | } | |
691 | ||
692 | cell->proc_link.pprev = p; | |
693 | cell->proc_link.next = *p; | |
694 | rcu_assign_pointer(*p, &cell->proc_link.next); | |
695 | if (cell->proc_link.next) | |
696 | cell->proc_link.next->pprev = &cell->proc_link.next; | |
697 | ||
0da0b7fd DH |
698 | afs_dynroot_mkdir(net, cell); |
699 | mutex_unlock(&net->proc_cells_lock); | |
989782dc DH |
700 | return 0; |
701 | } | |
702 | ||
703 | /* | |
704 | * Deactivate a cell. | |
705 | */ | |
706 | static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell) | |
707 | { | |
708 | _enter("%s", cell->name); | |
1da177e4 | 709 | |
5b86d4ff | 710 | afs_proc_cell_remove(cell); |
1da177e4 | 711 | |
0da0b7fd | 712 | mutex_lock(&net->proc_cells_lock); |
6b3944e4 | 713 | hlist_del_rcu(&cell->proc_link); |
0da0b7fd DH |
714 | afs_dynroot_rmdir(net, cell); |
715 | mutex_unlock(&net->proc_cells_lock); | |
1da177e4 | 716 | |
989782dc | 717 | _leave(""); |
ec26815a | 718 | } |
1da177e4 | 719 | |
1da177e4 | 720 | /* |
989782dc DH |
721 | * Manage a cell record, initialising and destroying it, maintaining its DNS |
722 | * records. | |
1da177e4 | 723 | */ |
88c853c3 | 724 | static void afs_manage_cell(struct afs_cell *cell) |
1da177e4 | 725 | { |
989782dc | 726 | struct afs_net *net = cell->net; |
88c853c3 | 727 | int ret, active; |
989782dc DH |
728 | |
729 | _enter("%s", cell->name); | |
730 | ||
731 | again: | |
732 | _debug("state %u", cell->state); | |
733 | switch (cell->state) { | |
734 | case AFS_CELL_INACTIVE: | |
735 | case AFS_CELL_FAILED: | |
92e3cc91 | 736 | down_write(&net->cells_lock); |
88c853c3 | 737 | active = 1; |
1d0e850a | 738 | if (atomic_try_cmpxchg_relaxed(&cell->active, &active, 0)) { |
989782dc | 739 | rb_erase(&cell->net_node, &net->cells); |
c56f9ec8 | 740 | trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), 0, |
dca54a7b | 741 | afs_cell_trace_unuse_delete); |
1d0e850a | 742 | smp_store_release(&cell->state, AFS_CELL_REMOVED); |
88c853c3 | 743 | } |
92e3cc91 | 744 | up_write(&net->cells_lock); |
1d0e850a DH |
745 | if (cell->state == AFS_CELL_REMOVED) { |
746 | wake_up_var(&cell->state); | |
989782dc | 747 | goto final_destruction; |
1d0e850a | 748 | } |
989782dc DH |
749 | if (cell->state == AFS_CELL_FAILED) |
750 | goto done; | |
d5c32c89 DH |
751 | smp_store_release(&cell->state, AFS_CELL_UNSET); |
752 | wake_up_var(&cell->state); | |
989782dc DH |
753 | goto again; |
754 | ||
755 | case AFS_CELL_UNSET: | |
d5c32c89 DH |
756 | smp_store_release(&cell->state, AFS_CELL_ACTIVATING); |
757 | wake_up_var(&cell->state); | |
989782dc DH |
758 | goto again; |
759 | ||
760 | case AFS_CELL_ACTIVATING: | |
761 | ret = afs_activate_cell(net, cell); | |
762 | if (ret < 0) | |
763 | goto activation_failed; | |
764 | ||
d5c32c89 DH |
765 | smp_store_release(&cell->state, AFS_CELL_ACTIVE); |
766 | wake_up_var(&cell->state); | |
989782dc DH |
767 | goto again; |
768 | ||
769 | case AFS_CELL_ACTIVE: | |
88c853c3 | 770 | if (atomic_read(&cell->active) > 1) { |
d5c32c89 DH |
771 | if (test_and_clear_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) { |
772 | ret = afs_update_cell(cell); | |
773 | if (ret < 0) | |
774 | cell->error = ret; | |
775 | } | |
989782dc DH |
776 | goto done; |
777 | } | |
d5c32c89 DH |
778 | smp_store_release(&cell->state, AFS_CELL_DEACTIVATING); |
779 | wake_up_var(&cell->state); | |
989782dc DH |
780 | goto again; |
781 | ||
782 | case AFS_CELL_DEACTIVATING: | |
88c853c3 | 783 | if (atomic_read(&cell->active) > 1) |
989782dc DH |
784 | goto reverse_deactivation; |
785 | afs_deactivate_cell(net, cell); | |
d5c32c89 DH |
786 | smp_store_release(&cell->state, AFS_CELL_INACTIVE); |
787 | wake_up_var(&cell->state); | |
989782dc DH |
788 | goto again; |
789 | ||
1d0e850a DH |
790 | case AFS_CELL_REMOVED: |
791 | goto done; | |
792 | ||
989782dc DH |
793 | default: |
794 | break; | |
795 | } | |
796 | _debug("bad state %u", cell->state); | |
797 | BUG(); /* Unhandled state */ | |
798 | ||
799 | activation_failed: | |
800 | cell->error = ret; | |
801 | afs_deactivate_cell(net, cell); | |
802 | ||
d5c32c89 DH |
803 | smp_store_release(&cell->state, AFS_CELL_FAILED); /* vs error */ |
804 | wake_up_var(&cell->state); | |
989782dc DH |
805 | goto again; |
806 | ||
807 | reverse_deactivation: | |
d5c32c89 DH |
808 | smp_store_release(&cell->state, AFS_CELL_ACTIVE); |
809 | wake_up_var(&cell->state); | |
989782dc DH |
810 | _leave(" [deact->act]"); |
811 | return; | |
812 | ||
813 | done: | |
814 | _leave(" [done %u]", cell->state); | |
815 | return; | |
816 | ||
817 | final_destruction: | |
88c853c3 | 818 | /* The root volume is pinning the cell */ |
445f9b69 | 819 | afs_put_volume(cell->root_volume, afs_volume_trace_put_cell_root); |
88c853c3 | 820 | cell->root_volume = NULL; |
dca54a7b | 821 | afs_put_cell(cell, afs_cell_trace_put_destroy); |
88c853c3 DH |
822 | } |
823 | ||
824 | static void afs_manage_cell_work(struct work_struct *work) | |
825 | { | |
826 | struct afs_cell *cell = container_of(work, struct afs_cell, manager); | |
827 | ||
828 | afs_manage_cell(cell); | |
dca54a7b | 829 | afs_put_cell(cell, afs_cell_trace_put_queue_work); |
989782dc DH |
830 | } |
831 | ||
832 | /* | |
833 | * Manage the records of cells known to a network namespace. This includes | |
834 | * updating the DNS records and garbage collecting unused cells that were | |
835 | * automatically added. | |
836 | * | |
837 | * Note that constructed cell records may only be removed from net->cells by | |
838 | * this work item, so it is safe for this work item to stash a cursor pointing | |
839 | * into the tree and then return to caller (provided it skips cells that are | |
840 | * still under construction). | |
841 | * | |
842 | * Note also that we were given an increment on net->cells_outstanding by | |
843 | * whoever queued us that we need to deal with before returning. | |
844 | */ | |
845 | void afs_manage_cells(struct work_struct *work) | |
846 | { | |
847 | struct afs_net *net = container_of(work, struct afs_net, cells_manager); | |
848 | struct rb_node *cursor; | |
849 | time64_t now = ktime_get_real_seconds(), next_manage = TIME64_MAX; | |
850 | bool purging = !net->live; | |
1da177e4 LT |
851 | |
852 | _enter(""); | |
853 | ||
989782dc DH |
854 | /* Trawl the cell database looking for cells that have expired from |
855 | * lack of use and cells whose DNS results have expired and dispatch | |
856 | * their managers. | |
857 | */ | |
92e3cc91 | 858 | down_read(&net->cells_lock); |
1da177e4 | 859 | |
989782dc DH |
860 | for (cursor = rb_first(&net->cells); cursor; cursor = rb_next(cursor)) { |
861 | struct afs_cell *cell = | |
862 | rb_entry(cursor, struct afs_cell, net_node); | |
88c853c3 | 863 | unsigned active; |
989782dc | 864 | bool sched_cell = false; |
08e0e7c8 | 865 | |
88c853c3 | 866 | active = atomic_read(&cell->active); |
c56f9ec8 | 867 | trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), |
dca54a7b | 868 | active, afs_cell_trace_manage); |
989782dc | 869 | |
88c853c3 | 870 | ASSERTCMP(active, >=, 1); |
989782dc DH |
871 | |
872 | if (purging) { | |
dca54a7b DH |
873 | if (test_and_clear_bit(AFS_CELL_FL_NO_GC, &cell->flags)) { |
874 | active = atomic_dec_return(&cell->active); | |
c56f9ec8 | 875 | trace_afs_cell(cell->debug_id, refcount_read(&cell->ref), |
dca54a7b DH |
876 | active, afs_cell_trace_unuse_pin); |
877 | } | |
989782dc | 878 | } |
1da177e4 | 879 | |
88c853c3 | 880 | if (active == 1) { |
d5c32c89 | 881 | struct afs_vlserver_list *vllist; |
989782dc | 882 | time64_t expire_at = cell->last_inactive; |
1da177e4 | 883 | |
d5c32c89 DH |
884 | read_lock(&cell->vl_servers_lock); |
885 | vllist = rcu_dereference_protected( | |
886 | cell->vl_servers, | |
887 | lockdep_is_held(&cell->vl_servers_lock)); | |
888 | if (vllist->nr_servers > 0) | |
989782dc | 889 | expire_at += afs_cell_gc_delay; |
d5c32c89 | 890 | read_unlock(&cell->vl_servers_lock); |
989782dc DH |
891 | if (purging || expire_at <= now) |
892 | sched_cell = true; | |
893 | else if (expire_at < next_manage) | |
894 | next_manage = expire_at; | |
1da177e4 LT |
895 | } |
896 | ||
989782dc | 897 | if (!purging) { |
d5c32c89 | 898 | if (test_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) |
989782dc | 899 | sched_cell = true; |
989782dc DH |
900 | } |
901 | ||
902 | if (sched_cell) | |
dca54a7b | 903 | afs_queue_cell(cell, afs_cell_trace_get_queue_manage); |
989782dc DH |
904 | } |
905 | ||
92e3cc91 | 906 | up_read(&net->cells_lock); |
1da177e4 | 907 | |
989782dc DH |
908 | /* Update the timer on the way out. We have to pass an increment on |
909 | * cells_outstanding in the namespace that we are in to the timer or | |
910 | * the work scheduler. | |
911 | */ | |
912 | if (!purging && next_manage < TIME64_MAX) { | |
913 | now = ktime_get_real_seconds(); | |
1da177e4 | 914 | |
989782dc DH |
915 | if (next_manage - now <= 0) { |
916 | if (queue_work(afs_wq, &net->cells_manager)) | |
917 | atomic_inc(&net->cells_outstanding); | |
918 | } else { | |
919 | afs_set_cell_timer(net, next_manage - now); | |
1da177e4 LT |
920 | } |
921 | } | |
922 | ||
989782dc DH |
923 | afs_dec_cells_outstanding(net); |
924 | _leave(" [%d]", atomic_read(&net->cells_outstanding)); | |
925 | } | |
926 | ||
927 | /* | |
928 | * Purge in-memory cell database. | |
929 | */ | |
930 | void afs_cell_purge(struct afs_net *net) | |
931 | { | |
932 | struct afs_cell *ws; | |
933 | ||
934 | _enter(""); | |
935 | ||
92e3cc91 DH |
936 | down_write(&net->cells_lock); |
937 | ws = net->ws_cell; | |
938 | net->ws_cell = NULL; | |
939 | up_write(&net->cells_lock); | |
dca54a7b | 940 | afs_unuse_cell(net, ws, afs_cell_trace_unuse_ws); |
989782dc DH |
941 | |
942 | _debug("del timer"); | |
943 | if (del_timer_sync(&net->cells_timer)) | |
944 | atomic_dec(&net->cells_outstanding); | |
945 | ||
946 | _debug("kick mgr"); | |
947 | afs_queue_cell_manager(net); | |
948 | ||
949 | _debug("wait"); | |
ab1fbe32 PZ |
950 | wait_var_event(&net->cells_outstanding, |
951 | !atomic_read(&net->cells_outstanding)); | |
1da177e4 | 952 | _leave(""); |
ec26815a | 953 | } |