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1da177e4 LT |
1 | /* cell.c: AFS cell and server record management |
2 | * | |
3 | * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU General Public License | |
8 | * as published by the Free Software Foundation; either version | |
9 | * 2 of the License, or (at your option) any later version. | |
10 | */ | |
11 | ||
12 | #include <linux/module.h> | |
1da177e4 LT |
13 | #include <linux/slab.h> |
14 | #include <rxrpc/peer.h> | |
15 | #include <rxrpc/connection.h> | |
16 | #include "volume.h" | |
17 | #include "cell.h" | |
18 | #include "server.h" | |
19 | #include "transport.h" | |
20 | #include "vlclient.h" | |
21 | #include "kafstimod.h" | |
22 | #include "super.h" | |
23 | #include "internal.h" | |
24 | ||
25 | DECLARE_RWSEM(afs_proc_cells_sem); | |
26 | LIST_HEAD(afs_proc_cells); | |
27 | ||
28 | static struct list_head afs_cells = LIST_HEAD_INIT(afs_cells); | |
29 | static DEFINE_RWLOCK(afs_cells_lock); | |
30 | static DECLARE_RWSEM(afs_cells_sem); /* add/remove serialisation */ | |
31 | static struct afs_cell *afs_cell_root; | |
32 | ||
33 | #ifdef AFS_CACHING_SUPPORT | |
34 | static cachefs_match_val_t afs_cell_cache_match(void *target, | |
35 | const void *entry); | |
36 | static void afs_cell_cache_update(void *source, void *entry); | |
37 | ||
38 | struct cachefs_index_def afs_cache_cell_index_def = { | |
39 | .name = "cell_ix", | |
40 | .data_size = sizeof(struct afs_cache_cell), | |
41 | .keys[0] = { CACHEFS_INDEX_KEYS_ASCIIZ, 64 }, | |
42 | .match = afs_cell_cache_match, | |
43 | .update = afs_cell_cache_update, | |
44 | }; | |
45 | #endif | |
46 | ||
47 | /*****************************************************************************/ | |
48 | /* | |
49 | * create a cell record | |
50 | * - "name" is the name of the cell | |
51 | * - "vllist" is a colon separated list of IP addresses in "a.b.c.d" format | |
52 | */ | |
53 | int afs_cell_create(const char *name, char *vllist, struct afs_cell **_cell) | |
54 | { | |
55 | struct afs_cell *cell; | |
56 | char *next; | |
57 | int ret; | |
58 | ||
59 | _enter("%s", name); | |
60 | ||
61 | BUG_ON(!name); /* TODO: want to look up "this cell" in the cache */ | |
62 | ||
63 | /* allocate and initialise a cell record */ | |
64 | cell = kmalloc(sizeof(struct afs_cell) + strlen(name) + 1, GFP_KERNEL); | |
65 | if (!cell) { | |
66 | _leave(" = -ENOMEM"); | |
67 | return -ENOMEM; | |
68 | } | |
69 | ||
70 | down_write(&afs_cells_sem); | |
71 | ||
72 | memset(cell, 0, sizeof(struct afs_cell)); | |
73 | atomic_set(&cell->usage, 0); | |
74 | ||
75 | INIT_LIST_HEAD(&cell->link); | |
76 | ||
77 | rwlock_init(&cell->sv_lock); | |
78 | INIT_LIST_HEAD(&cell->sv_list); | |
79 | INIT_LIST_HEAD(&cell->sv_graveyard); | |
80 | spin_lock_init(&cell->sv_gylock); | |
81 | ||
82 | init_rwsem(&cell->vl_sem); | |
83 | INIT_LIST_HEAD(&cell->vl_list); | |
84 | INIT_LIST_HEAD(&cell->vl_graveyard); | |
85 | spin_lock_init(&cell->vl_gylock); | |
86 | ||
87 | strcpy(cell->name,name); | |
88 | ||
89 | /* fill in the VL server list from the rest of the string */ | |
90 | ret = -EINVAL; | |
91 | do { | |
92 | unsigned a, b, c, d; | |
93 | ||
94 | next = strchr(vllist, ':'); | |
95 | if (next) | |
96 | *next++ = 0; | |
97 | ||
98 | if (sscanf(vllist, "%u.%u.%u.%u", &a, &b, &c, &d) != 4) | |
99 | goto badaddr; | |
100 | ||
101 | if (a > 255 || b > 255 || c > 255 || d > 255) | |
102 | goto badaddr; | |
103 | ||
104 | cell->vl_addrs[cell->vl_naddrs++].s_addr = | |
105 | htonl((a << 24) | (b << 16) | (c << 8) | d); | |
106 | ||
107 | if (cell->vl_naddrs >= AFS_CELL_MAX_ADDRS) | |
108 | break; | |
109 | ||
110 | } while(vllist = next, vllist); | |
111 | ||
112 | /* add a proc dir for this cell */ | |
113 | ret = afs_proc_cell_setup(cell); | |
114 | if (ret < 0) | |
115 | goto error; | |
116 | ||
117 | #ifdef AFS_CACHING_SUPPORT | |
118 | /* put it up for caching */ | |
119 | cachefs_acquire_cookie(afs_cache_netfs.primary_index, | |
120 | &afs_vlocation_cache_index_def, | |
121 | cell, | |
122 | &cell->cache); | |
123 | #endif | |
124 | ||
125 | /* add to the cell lists */ | |
126 | write_lock(&afs_cells_lock); | |
127 | list_add_tail(&cell->link, &afs_cells); | |
128 | write_unlock(&afs_cells_lock); | |
129 | ||
130 | down_write(&afs_proc_cells_sem); | |
131 | list_add_tail(&cell->proc_link, &afs_proc_cells); | |
132 | up_write(&afs_proc_cells_sem); | |
133 | ||
134 | *_cell = cell; | |
135 | up_write(&afs_cells_sem); | |
136 | ||
137 | _leave(" = 0 (%p)", cell); | |
138 | return 0; | |
139 | ||
140 | badaddr: | |
141 | printk(KERN_ERR "kAFS: bad VL server IP address: '%s'\n", vllist); | |
142 | error: | |
143 | up_write(&afs_cells_sem); | |
144 | kfree(cell); | |
145 | _leave(" = %d", ret); | |
146 | return ret; | |
147 | } /* end afs_cell_create() */ | |
148 | ||
149 | /*****************************************************************************/ | |
150 | /* | |
151 | * initialise the cell database from module parameters | |
152 | */ | |
153 | int afs_cell_init(char *rootcell) | |
154 | { | |
155 | struct afs_cell *old_root, *new_root; | |
156 | char *cp; | |
157 | int ret; | |
158 | ||
159 | _enter(""); | |
160 | ||
161 | if (!rootcell) { | |
162 | /* module is loaded with no parameters, or built statically. | |
163 | * - in the future we might initialize cell DB here. | |
164 | */ | |
165 | _leave(" = 0 (but no root)"); | |
166 | return 0; | |
167 | } | |
168 | ||
169 | cp = strchr(rootcell, ':'); | |
170 | if (!cp) { | |
171 | printk(KERN_ERR "kAFS: no VL server IP addresses specified\n"); | |
172 | _leave(" = %d (no colon)", -EINVAL); | |
173 | return -EINVAL; | |
174 | } | |
175 | ||
176 | /* allocate a cell record for the root cell */ | |
177 | *cp++ = 0; | |
178 | ret = afs_cell_create(rootcell, cp, &new_root); | |
179 | if (ret < 0) { | |
180 | _leave(" = %d", ret); | |
181 | return ret; | |
182 | } | |
183 | ||
184 | /* as afs_put_cell() takes locks by itself, we have to do | |
185 | * a little gymnastics to be race-free. | |
186 | */ | |
187 | afs_get_cell(new_root); | |
188 | ||
189 | write_lock(&afs_cells_lock); | |
190 | while (afs_cell_root) { | |
191 | old_root = afs_cell_root; | |
192 | afs_cell_root = NULL; | |
193 | write_unlock(&afs_cells_lock); | |
194 | afs_put_cell(old_root); | |
195 | write_lock(&afs_cells_lock); | |
196 | } | |
197 | afs_cell_root = new_root; | |
198 | write_unlock(&afs_cells_lock); | |
199 | ||
200 | _leave(" = %d", ret); | |
201 | return ret; | |
202 | ||
203 | } /* end afs_cell_init() */ | |
204 | ||
205 | /*****************************************************************************/ | |
206 | /* | |
207 | * lookup a cell record | |
208 | */ | |
209 | int afs_cell_lookup(const char *name, unsigned namesz, struct afs_cell **_cell) | |
210 | { | |
211 | struct afs_cell *cell; | |
212 | int ret; | |
213 | ||
214 | _enter("\"%*.*s\",", namesz, namesz, name ? name : ""); | |
215 | ||
216 | *_cell = NULL; | |
217 | ||
218 | if (name) { | |
219 | /* if the cell was named, look for it in the cell record list */ | |
220 | ret = -ENOENT; | |
221 | cell = NULL; | |
222 | read_lock(&afs_cells_lock); | |
223 | ||
224 | list_for_each_entry(cell, &afs_cells, link) { | |
225 | if (strncmp(cell->name, name, namesz) == 0) { | |
226 | afs_get_cell(cell); | |
227 | goto found; | |
228 | } | |
229 | } | |
230 | cell = NULL; | |
231 | found: | |
232 | ||
233 | read_unlock(&afs_cells_lock); | |
234 | ||
235 | if (cell) | |
236 | ret = 0; | |
237 | } | |
238 | else { | |
239 | read_lock(&afs_cells_lock); | |
240 | ||
241 | cell = afs_cell_root; | |
242 | if (!cell) { | |
243 | /* this should not happen unless user tries to mount | |
244 | * when root cell is not set. Return an impossibly | |
245 | * bizzare errno to alert the user. Things like | |
246 | * ENOENT might be "more appropriate" but they happen | |
247 | * for other reasons. | |
248 | */ | |
249 | ret = -EDESTADDRREQ; | |
250 | } | |
251 | else { | |
252 | afs_get_cell(cell); | |
253 | ret = 0; | |
254 | } | |
255 | ||
256 | read_unlock(&afs_cells_lock); | |
257 | } | |
258 | ||
259 | *_cell = cell; | |
260 | _leave(" = %d (%p)", ret, cell); | |
261 | return ret; | |
262 | ||
263 | } /* end afs_cell_lookup() */ | |
264 | ||
265 | /*****************************************************************************/ | |
266 | /* | |
267 | * try and get a cell record | |
268 | */ | |
269 | struct afs_cell *afs_get_cell_maybe(struct afs_cell **_cell) | |
270 | { | |
271 | struct afs_cell *cell; | |
272 | ||
273 | write_lock(&afs_cells_lock); | |
274 | ||
275 | cell = *_cell; | |
276 | if (cell && !list_empty(&cell->link)) | |
277 | afs_get_cell(cell); | |
278 | else | |
279 | cell = NULL; | |
280 | ||
281 | write_unlock(&afs_cells_lock); | |
282 | ||
283 | return cell; | |
284 | } /* end afs_get_cell_maybe() */ | |
285 | ||
286 | /*****************************************************************************/ | |
287 | /* | |
288 | * destroy a cell record | |
289 | */ | |
290 | void afs_put_cell(struct afs_cell *cell) | |
291 | { | |
292 | if (!cell) | |
293 | return; | |
294 | ||
295 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
296 | ||
297 | /* sanity check */ | |
298 | BUG_ON(atomic_read(&cell->usage) <= 0); | |
299 | ||
300 | /* to prevent a race, the decrement and the dequeue must be effectively | |
301 | * atomic */ | |
302 | write_lock(&afs_cells_lock); | |
303 | ||
304 | if (likely(!atomic_dec_and_test(&cell->usage))) { | |
305 | write_unlock(&afs_cells_lock); | |
306 | _leave(""); | |
307 | return; | |
308 | } | |
309 | ||
310 | write_unlock(&afs_cells_lock); | |
311 | ||
312 | BUG_ON(!list_empty(&cell->sv_list)); | |
313 | BUG_ON(!list_empty(&cell->sv_graveyard)); | |
314 | BUG_ON(!list_empty(&cell->vl_list)); | |
315 | BUG_ON(!list_empty(&cell->vl_graveyard)); | |
316 | ||
317 | _leave(" [unused]"); | |
318 | } /* end afs_put_cell() */ | |
319 | ||
320 | /*****************************************************************************/ | |
321 | /* | |
322 | * destroy a cell record | |
323 | */ | |
324 | static void afs_cell_destroy(struct afs_cell *cell) | |
325 | { | |
326 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
327 | ||
328 | /* to prevent a race, the decrement and the dequeue must be effectively | |
329 | * atomic */ | |
330 | write_lock(&afs_cells_lock); | |
331 | ||
332 | /* sanity check */ | |
333 | BUG_ON(atomic_read(&cell->usage) != 0); | |
334 | ||
335 | list_del_init(&cell->link); | |
336 | ||
337 | write_unlock(&afs_cells_lock); | |
338 | ||
339 | down_write(&afs_cells_sem); | |
340 | ||
341 | afs_proc_cell_remove(cell); | |
342 | ||
343 | down_write(&afs_proc_cells_sem); | |
344 | list_del_init(&cell->proc_link); | |
345 | up_write(&afs_proc_cells_sem); | |
346 | ||
347 | #ifdef AFS_CACHING_SUPPORT | |
348 | cachefs_relinquish_cookie(cell->cache, 0); | |
349 | #endif | |
350 | ||
351 | up_write(&afs_cells_sem); | |
352 | ||
353 | BUG_ON(!list_empty(&cell->sv_list)); | |
354 | BUG_ON(!list_empty(&cell->sv_graveyard)); | |
355 | BUG_ON(!list_empty(&cell->vl_list)); | |
356 | BUG_ON(!list_empty(&cell->vl_graveyard)); | |
357 | ||
358 | /* finish cleaning up the cell */ | |
359 | kfree(cell); | |
360 | ||
361 | _leave(" [destroyed]"); | |
362 | } /* end afs_cell_destroy() */ | |
363 | ||
364 | /*****************************************************************************/ | |
365 | /* | |
366 | * lookup the server record corresponding to an Rx RPC peer | |
367 | */ | |
368 | int afs_server_find_by_peer(const struct rxrpc_peer *peer, | |
369 | struct afs_server **_server) | |
370 | { | |
371 | struct afs_server *server; | |
372 | struct afs_cell *cell; | |
373 | ||
374 | _enter("%p{a=%08x},", peer, ntohl(peer->addr.s_addr)); | |
375 | ||
376 | /* search the cell list */ | |
377 | read_lock(&afs_cells_lock); | |
378 | ||
379 | list_for_each_entry(cell, &afs_cells, link) { | |
380 | ||
381 | _debug("? cell %s",cell->name); | |
382 | ||
383 | write_lock(&cell->sv_lock); | |
384 | ||
385 | /* check the active list */ | |
386 | list_for_each_entry(server, &cell->sv_list, link) { | |
387 | _debug("?? server %08x", ntohl(server->addr.s_addr)); | |
388 | ||
389 | if (memcmp(&server->addr, &peer->addr, | |
390 | sizeof(struct in_addr)) == 0) | |
391 | goto found_server; | |
392 | } | |
393 | ||
394 | /* check the inactive list */ | |
395 | spin_lock(&cell->sv_gylock); | |
396 | list_for_each_entry(server, &cell->sv_graveyard, link) { | |
397 | _debug("?? dead server %08x", | |
398 | ntohl(server->addr.s_addr)); | |
399 | ||
400 | if (memcmp(&server->addr, &peer->addr, | |
401 | sizeof(struct in_addr)) == 0) | |
402 | goto found_dead_server; | |
403 | } | |
404 | spin_unlock(&cell->sv_gylock); | |
405 | ||
406 | write_unlock(&cell->sv_lock); | |
407 | } | |
408 | read_unlock(&afs_cells_lock); | |
409 | ||
410 | _leave(" = -ENOENT"); | |
411 | return -ENOENT; | |
412 | ||
413 | /* we found it in the graveyard - resurrect it */ | |
414 | found_dead_server: | |
f116629d | 415 | list_move_tail(&server->link, &cell->sv_list); |
1da177e4 LT |
416 | afs_get_server(server); |
417 | afs_kafstimod_del_timer(&server->timeout); | |
418 | spin_unlock(&cell->sv_gylock); | |
419 | goto success; | |
420 | ||
421 | /* we found it - increment its ref count and return it */ | |
422 | found_server: | |
423 | afs_get_server(server); | |
424 | ||
425 | success: | |
426 | write_unlock(&cell->sv_lock); | |
427 | read_unlock(&afs_cells_lock); | |
428 | ||
429 | *_server = server; | |
430 | _leave(" = 0 (s=%p c=%p)", server, cell); | |
431 | return 0; | |
432 | ||
433 | } /* end afs_server_find_by_peer() */ | |
434 | ||
435 | /*****************************************************************************/ | |
436 | /* | |
437 | * purge in-memory cell database on module unload or afs_init() failure | |
438 | * - the timeout daemon is stopped before calling this | |
439 | */ | |
440 | void afs_cell_purge(void) | |
441 | { | |
442 | struct afs_vlocation *vlocation; | |
443 | struct afs_cell *cell; | |
444 | ||
445 | _enter(""); | |
446 | ||
447 | afs_put_cell(afs_cell_root); | |
448 | ||
449 | while (!list_empty(&afs_cells)) { | |
450 | cell = NULL; | |
451 | ||
452 | /* remove the next cell from the front of the list */ | |
453 | write_lock(&afs_cells_lock); | |
454 | ||
455 | if (!list_empty(&afs_cells)) { | |
456 | cell = list_entry(afs_cells.next, | |
457 | struct afs_cell, link); | |
458 | list_del_init(&cell->link); | |
459 | } | |
460 | ||
461 | write_unlock(&afs_cells_lock); | |
462 | ||
463 | if (cell) { | |
464 | _debug("PURGING CELL %s (%d)", | |
465 | cell->name, atomic_read(&cell->usage)); | |
466 | ||
467 | BUG_ON(!list_empty(&cell->sv_list)); | |
468 | BUG_ON(!list_empty(&cell->vl_list)); | |
469 | ||
470 | /* purge the cell's VL graveyard list */ | |
471 | _debug(" - clearing VL graveyard"); | |
472 | ||
473 | spin_lock(&cell->vl_gylock); | |
474 | ||
475 | while (!list_empty(&cell->vl_graveyard)) { | |
476 | vlocation = list_entry(cell->vl_graveyard.next, | |
477 | struct afs_vlocation, | |
478 | link); | |
479 | list_del_init(&vlocation->link); | |
480 | ||
481 | afs_kafstimod_del_timer(&vlocation->timeout); | |
482 | ||
483 | spin_unlock(&cell->vl_gylock); | |
484 | ||
485 | afs_vlocation_do_timeout(vlocation); | |
486 | /* TODO: race if move to use krxtimod instead | |
487 | * of kafstimod */ | |
488 | ||
489 | spin_lock(&cell->vl_gylock); | |
490 | } | |
491 | ||
492 | spin_unlock(&cell->vl_gylock); | |
493 | ||
494 | /* purge the cell's server graveyard list */ | |
495 | _debug(" - clearing server graveyard"); | |
496 | ||
497 | spin_lock(&cell->sv_gylock); | |
498 | ||
499 | while (!list_empty(&cell->sv_graveyard)) { | |
500 | struct afs_server *server; | |
501 | ||
502 | server = list_entry(cell->sv_graveyard.next, | |
503 | struct afs_server, link); | |
504 | list_del_init(&server->link); | |
505 | ||
506 | afs_kafstimod_del_timer(&server->timeout); | |
507 | ||
508 | spin_unlock(&cell->sv_gylock); | |
509 | ||
510 | afs_server_do_timeout(server); | |
511 | ||
512 | spin_lock(&cell->sv_gylock); | |
513 | } | |
514 | ||
515 | spin_unlock(&cell->sv_gylock); | |
516 | ||
517 | /* now the cell should be left with no references */ | |
518 | afs_cell_destroy(cell); | |
519 | } | |
520 | } | |
521 | ||
522 | _leave(""); | |
523 | } /* end afs_cell_purge() */ | |
524 | ||
525 | /*****************************************************************************/ | |
526 | /* | |
527 | * match a cell record obtained from the cache | |
528 | */ | |
529 | #ifdef AFS_CACHING_SUPPORT | |
530 | static cachefs_match_val_t afs_cell_cache_match(void *target, | |
531 | const void *entry) | |
532 | { | |
533 | const struct afs_cache_cell *ccell = entry; | |
534 | struct afs_cell *cell = target; | |
535 | ||
536 | _enter("{%s},{%s}", ccell->name, cell->name); | |
537 | ||
538 | if (strncmp(ccell->name, cell->name, sizeof(ccell->name)) == 0) { | |
539 | _leave(" = SUCCESS"); | |
540 | return CACHEFS_MATCH_SUCCESS; | |
541 | } | |
542 | ||
543 | _leave(" = FAILED"); | |
544 | return CACHEFS_MATCH_FAILED; | |
545 | } /* end afs_cell_cache_match() */ | |
546 | #endif | |
547 | ||
548 | /*****************************************************************************/ | |
549 | /* | |
550 | * update a cell record in the cache | |
551 | */ | |
552 | #ifdef AFS_CACHING_SUPPORT | |
553 | static void afs_cell_cache_update(void *source, void *entry) | |
554 | { | |
555 | struct afs_cache_cell *ccell = entry; | |
556 | struct afs_cell *cell = source; | |
557 | ||
558 | _enter("%p,%p", source, entry); | |
559 | ||
560 | strncpy(ccell->name, cell->name, sizeof(ccell->name)); | |
561 | ||
562 | memcpy(ccell->vl_servers, | |
563 | cell->vl_addrs, | |
564 | min(sizeof(ccell->vl_servers), sizeof(cell->vl_addrs))); | |
565 | ||
566 | } /* end afs_cell_cache_update() */ | |
567 | #endif |