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ec26815a | 1 | /* AFS cell and server record management |
1da177e4 LT |
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 | 13 | #include <linux/slab.h> |
00d3b7a4 DH |
14 | #include <linux/key.h> |
15 | #include <linux/ctype.h> | |
e8edc6e0 | 16 | #include <linux/sched.h> |
00d3b7a4 | 17 | #include <keys/rxrpc-type.h> |
1da177e4 LT |
18 | #include "internal.h" |
19 | ||
20 | DECLARE_RWSEM(afs_proc_cells_sem); | |
21 | LIST_HEAD(afs_proc_cells); | |
22 | ||
23 | static struct list_head afs_cells = LIST_HEAD_INIT(afs_cells); | |
24 | static DEFINE_RWLOCK(afs_cells_lock); | |
25 | static DECLARE_RWSEM(afs_cells_sem); /* add/remove serialisation */ | |
08e0e7c8 | 26 | static DECLARE_WAIT_QUEUE_HEAD(afs_cells_freeable_wq); |
1da177e4 LT |
27 | static struct afs_cell *afs_cell_root; |
28 | ||
1da177e4 | 29 | /* |
00d3b7a4 DH |
30 | * allocate a cell record and fill in its name, VL server address list and |
31 | * allocate an anonymous key | |
1da177e4 | 32 | */ |
00d3b7a4 | 33 | static struct afs_cell *afs_cell_alloc(const char *name, char *vllist) |
1da177e4 LT |
34 | { |
35 | struct afs_cell *cell; | |
00d3b7a4 DH |
36 | size_t namelen; |
37 | char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp, *next; | |
1da177e4 LT |
38 | int ret; |
39 | ||
08e0e7c8 | 40 | _enter("%s,%s", name, vllist); |
1da177e4 LT |
41 | |
42 | BUG_ON(!name); /* TODO: want to look up "this cell" in the cache */ | |
43 | ||
00d3b7a4 DH |
44 | namelen = strlen(name); |
45 | if (namelen > AFS_MAXCELLNAME) | |
46 | return ERR_PTR(-ENAMETOOLONG); | |
47 | ||
1da177e4 | 48 | /* allocate and initialise a cell record */ |
00d3b7a4 | 49 | cell = kzalloc(sizeof(struct afs_cell) + namelen + 1, GFP_KERNEL); |
1da177e4 LT |
50 | if (!cell) { |
51 | _leave(" = -ENOMEM"); | |
08e0e7c8 | 52 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
53 | } |
54 | ||
00d3b7a4 DH |
55 | memcpy(cell->name, name, namelen); |
56 | cell->name[namelen] = 0; | |
1da177e4 | 57 | |
08e0e7c8 | 58 | atomic_set(&cell->usage, 1); |
1da177e4 | 59 | INIT_LIST_HEAD(&cell->link); |
08e0e7c8 DH |
60 | rwlock_init(&cell->servers_lock); |
61 | INIT_LIST_HEAD(&cell->servers); | |
1da177e4 LT |
62 | init_rwsem(&cell->vl_sem); |
63 | INIT_LIST_HEAD(&cell->vl_list); | |
08e0e7c8 | 64 | spin_lock_init(&cell->vl_lock); |
1da177e4 | 65 | |
1da177e4 | 66 | /* fill in the VL server list from the rest of the string */ |
1da177e4 LT |
67 | do { |
68 | unsigned a, b, c, d; | |
69 | ||
70 | next = strchr(vllist, ':'); | |
71 | if (next) | |
72 | *next++ = 0; | |
73 | ||
74 | if (sscanf(vllist, "%u.%u.%u.%u", &a, &b, &c, &d) != 4) | |
00d3b7a4 | 75 | goto bad_address; |
1da177e4 LT |
76 | |
77 | if (a > 255 || b > 255 || c > 255 || d > 255) | |
00d3b7a4 | 78 | goto bad_address; |
1da177e4 LT |
79 | |
80 | cell->vl_addrs[cell->vl_naddrs++].s_addr = | |
81 | htonl((a << 24) | (b << 16) | (c << 8) | d); | |
82 | ||
00d3b7a4 DH |
83 | } while (cell->vl_naddrs < AFS_CELL_MAX_ADDRS && (vllist = next)); |
84 | ||
85 | /* create a key to represent an anonymous user */ | |
86 | memcpy(keyname, "afs@", 4); | |
87 | dp = keyname + 4; | |
88 | cp = cell->name; | |
89 | do { | |
90 | *dp++ = toupper(*cp); | |
91 | } while (*cp++); | |
92 | cell->anonymous_key = key_alloc(&key_type_rxrpc, keyname, 0, 0, current, | |
93 | KEY_POS_SEARCH, KEY_ALLOC_NOT_IN_QUOTA); | |
94 | if (IS_ERR(cell->anonymous_key)) { | |
95 | _debug("no key"); | |
96 | ret = PTR_ERR(cell->anonymous_key); | |
97 | goto error; | |
98 | } | |
99 | ||
100 | ret = key_instantiate_and_link(cell->anonymous_key, NULL, 0, | |
101 | NULL, NULL); | |
102 | if (ret < 0) { | |
103 | _debug("instantiate failed"); | |
104 | goto error; | |
105 | } | |
106 | ||
107 | _debug("anon key %p{%x}", | |
108 | cell->anonymous_key, key_serial(cell->anonymous_key)); | |
109 | ||
110 | _leave(" = %p", cell); | |
111 | return cell; | |
112 | ||
113 | bad_address: | |
114 | printk(KERN_ERR "kAFS: bad VL server IP address\n"); | |
115 | ret = -EINVAL; | |
116 | error: | |
117 | key_put(cell->anonymous_key); | |
118 | kfree(cell); | |
119 | _leave(" = %d", ret); | |
120 | return ERR_PTR(ret); | |
121 | } | |
1da177e4 | 122 | |
00d3b7a4 DH |
123 | /* |
124 | * create a cell record | |
125 | * - "name" is the name of the cell | |
126 | * - "vllist" is a colon separated list of IP addresses in "a.b.c.d" format | |
127 | */ | |
128 | struct afs_cell *afs_cell_create(const char *name, char *vllist) | |
129 | { | |
130 | struct afs_cell *cell; | |
131 | int ret; | |
132 | ||
133 | _enter("%s,%s", name, vllist); | |
134 | ||
135 | cell = afs_cell_alloc(name, vllist); | |
136 | if (IS_ERR(cell)) { | |
137 | _leave(" = %ld", PTR_ERR(cell)); | |
138 | return cell; | |
139 | } | |
140 | ||
141 | down_write(&afs_cells_sem); | |
1da177e4 | 142 | |
08e0e7c8 | 143 | /* add a proc directory for this cell */ |
1da177e4 LT |
144 | ret = afs_proc_cell_setup(cell); |
145 | if (ret < 0) | |
146 | goto error; | |
147 | ||
148 | #ifdef AFS_CACHING_SUPPORT | |
149 | /* put it up for caching */ | |
150 | cachefs_acquire_cookie(afs_cache_netfs.primary_index, | |
151 | &afs_vlocation_cache_index_def, | |
152 | cell, | |
153 | &cell->cache); | |
154 | #endif | |
155 | ||
156 | /* add to the cell lists */ | |
157 | write_lock(&afs_cells_lock); | |
158 | list_add_tail(&cell->link, &afs_cells); | |
159 | write_unlock(&afs_cells_lock); | |
160 | ||
161 | down_write(&afs_proc_cells_sem); | |
162 | list_add_tail(&cell->proc_link, &afs_proc_cells); | |
163 | up_write(&afs_proc_cells_sem); | |
1da177e4 LT |
164 | up_write(&afs_cells_sem); |
165 | ||
08e0e7c8 DH |
166 | _leave(" = %p", cell); |
167 | return cell; | |
1da177e4 | 168 | |
ec26815a | 169 | error: |
1da177e4 | 170 | up_write(&afs_cells_sem); |
00d3b7a4 | 171 | key_put(cell->anonymous_key); |
1da177e4 LT |
172 | kfree(cell); |
173 | _leave(" = %d", ret); | |
08e0e7c8 | 174 | return ERR_PTR(ret); |
ec26815a | 175 | } |
1da177e4 | 176 | |
1da177e4 | 177 | /* |
08e0e7c8 DH |
178 | * set the root cell information |
179 | * - can be called with a module parameter string | |
180 | * - can be called from a write to /proc/fs/afs/rootcell | |
1da177e4 LT |
181 | */ |
182 | int afs_cell_init(char *rootcell) | |
183 | { | |
184 | struct afs_cell *old_root, *new_root; | |
185 | char *cp; | |
1da177e4 LT |
186 | |
187 | _enter(""); | |
188 | ||
189 | if (!rootcell) { | |
190 | /* module is loaded with no parameters, or built statically. | |
191 | * - in the future we might initialize cell DB here. | |
192 | */ | |
08e0e7c8 | 193 | _leave(" = 0 [no root]"); |
1da177e4 LT |
194 | return 0; |
195 | } | |
196 | ||
197 | cp = strchr(rootcell, ':'); | |
198 | if (!cp) { | |
199 | printk(KERN_ERR "kAFS: no VL server IP addresses specified\n"); | |
08e0e7c8 | 200 | _leave(" = -EINVAL"); |
1da177e4 LT |
201 | return -EINVAL; |
202 | } | |
203 | ||
204 | /* allocate a cell record for the root cell */ | |
205 | *cp++ = 0; | |
08e0e7c8 DH |
206 | new_root = afs_cell_create(rootcell, cp); |
207 | if (IS_ERR(new_root)) { | |
208 | _leave(" = %ld", PTR_ERR(new_root)); | |
209 | return PTR_ERR(new_root); | |
1da177e4 LT |
210 | } |
211 | ||
08e0e7c8 | 212 | /* install the new cell */ |
1da177e4 | 213 | write_lock(&afs_cells_lock); |
08e0e7c8 | 214 | old_root = afs_cell_root; |
1da177e4 LT |
215 | afs_cell_root = new_root; |
216 | write_unlock(&afs_cells_lock); | |
08e0e7c8 | 217 | afs_put_cell(old_root); |
1da177e4 | 218 | |
08e0e7c8 DH |
219 | _leave(" = 0"); |
220 | return 0; | |
ec26815a | 221 | } |
1da177e4 | 222 | |
1da177e4 LT |
223 | /* |
224 | * lookup a cell record | |
225 | */ | |
08e0e7c8 | 226 | struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz) |
1da177e4 LT |
227 | { |
228 | struct afs_cell *cell; | |
1da177e4 LT |
229 | |
230 | _enter("\"%*.*s\",", namesz, namesz, name ? name : ""); | |
231 | ||
08e0e7c8 DH |
232 | down_read(&afs_cells_sem); |
233 | read_lock(&afs_cells_lock); | |
1da177e4 LT |
234 | |
235 | if (name) { | |
236 | /* if the cell was named, look for it in the cell record list */ | |
1da177e4 LT |
237 | list_for_each_entry(cell, &afs_cells, link) { |
238 | if (strncmp(cell->name, name, namesz) == 0) { | |
239 | afs_get_cell(cell); | |
240 | goto found; | |
241 | } | |
242 | } | |
08e0e7c8 | 243 | cell = ERR_PTR(-ENOENT); |
1da177e4 | 244 | found: |
08e0e7c8 | 245 | ; |
ec26815a | 246 | } else { |
1da177e4 LT |
247 | cell = afs_cell_root; |
248 | if (!cell) { | |
249 | /* this should not happen unless user tries to mount | |
250 | * when root cell is not set. Return an impossibly | |
251 | * bizzare errno to alert the user. Things like | |
252 | * ENOENT might be "more appropriate" but they happen | |
253 | * for other reasons. | |
254 | */ | |
08e0e7c8 | 255 | cell = ERR_PTR(-EDESTADDRREQ); |
ec26815a | 256 | } else { |
1da177e4 | 257 | afs_get_cell(cell); |
1da177e4 LT |
258 | } |
259 | ||
1da177e4 LT |
260 | } |
261 | ||
08e0e7c8 DH |
262 | read_unlock(&afs_cells_lock); |
263 | up_read(&afs_cells_sem); | |
264 | _leave(" = %p", cell); | |
265 | return cell; | |
ec26815a | 266 | } |
1da177e4 | 267 | |
c1206a2c | 268 | #if 0 |
1da177e4 LT |
269 | /* |
270 | * try and get a cell record | |
271 | */ | |
08e0e7c8 | 272 | struct afs_cell *afs_get_cell_maybe(struct afs_cell *cell) |
1da177e4 | 273 | { |
1da177e4 LT |
274 | write_lock(&afs_cells_lock); |
275 | ||
1da177e4 LT |
276 | if (cell && !list_empty(&cell->link)) |
277 | afs_get_cell(cell); | |
278 | else | |
279 | cell = NULL; | |
280 | ||
281 | write_unlock(&afs_cells_lock); | |
1da177e4 | 282 | return cell; |
ec26815a | 283 | } |
c1206a2c | 284 | #endif /* 0 */ |
1da177e4 | 285 | |
1da177e4 LT |
286 | /* |
287 | * destroy a cell record | |
288 | */ | |
289 | void afs_put_cell(struct afs_cell *cell) | |
290 | { | |
291 | if (!cell) | |
292 | return; | |
293 | ||
294 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
295 | ||
08e0e7c8 | 296 | ASSERTCMP(atomic_read(&cell->usage), >, 0); |
1da177e4 LT |
297 | |
298 | /* to prevent a race, the decrement and the dequeue must be effectively | |
299 | * atomic */ | |
300 | write_lock(&afs_cells_lock); | |
301 | ||
302 | if (likely(!atomic_dec_and_test(&cell->usage))) { | |
303 | write_unlock(&afs_cells_lock); | |
304 | _leave(""); | |
305 | return; | |
306 | } | |
307 | ||
08e0e7c8 DH |
308 | ASSERT(list_empty(&cell->servers)); |
309 | ASSERT(list_empty(&cell->vl_list)); | |
310 | ||
1da177e4 LT |
311 | write_unlock(&afs_cells_lock); |
312 | ||
08e0e7c8 | 313 | wake_up(&afs_cells_freeable_wq); |
1da177e4 LT |
314 | |
315 | _leave(" [unused]"); | |
ec26815a | 316 | } |
1da177e4 | 317 | |
1da177e4 LT |
318 | /* |
319 | * destroy a cell record | |
08e0e7c8 DH |
320 | * - must be called with the afs_cells_sem write-locked |
321 | * - cell->link should have been broken by the caller | |
1da177e4 LT |
322 | */ |
323 | static void afs_cell_destroy(struct afs_cell *cell) | |
324 | { | |
325 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
326 | ||
08e0e7c8 DH |
327 | ASSERTCMP(atomic_read(&cell->usage), >=, 0); |
328 | ASSERT(list_empty(&cell->link)); | |
1da177e4 | 329 | |
08e0e7c8 DH |
330 | /* wait for everyone to stop using the cell */ |
331 | if (atomic_read(&cell->usage) > 0) { | |
332 | DECLARE_WAITQUEUE(myself, current); | |
1da177e4 | 333 | |
08e0e7c8 DH |
334 | _debug("wait for cell %s", cell->name); |
335 | set_current_state(TASK_UNINTERRUPTIBLE); | |
336 | add_wait_queue(&afs_cells_freeable_wq, &myself); | |
1da177e4 | 337 | |
08e0e7c8 DH |
338 | while (atomic_read(&cell->usage) > 0) { |
339 | schedule(); | |
340 | set_current_state(TASK_UNINTERRUPTIBLE); | |
341 | } | |
1da177e4 | 342 | |
08e0e7c8 DH |
343 | remove_wait_queue(&afs_cells_freeable_wq, &myself); |
344 | set_current_state(TASK_RUNNING); | |
345 | } | |
346 | ||
347 | _debug("cell dead"); | |
348 | ASSERTCMP(atomic_read(&cell->usage), ==, 0); | |
349 | ASSERT(list_empty(&cell->servers)); | |
350 | ASSERT(list_empty(&cell->vl_list)); | |
1da177e4 LT |
351 | |
352 | afs_proc_cell_remove(cell); | |
353 | ||
354 | down_write(&afs_proc_cells_sem); | |
355 | list_del_init(&cell->proc_link); | |
356 | up_write(&afs_proc_cells_sem); | |
357 | ||
358 | #ifdef AFS_CACHING_SUPPORT | |
359 | cachefs_relinquish_cookie(cell->cache, 0); | |
360 | #endif | |
361 | ||
00d3b7a4 | 362 | key_put(cell->anonymous_key); |
1da177e4 LT |
363 | kfree(cell); |
364 | ||
365 | _leave(" [destroyed]"); | |
ec26815a | 366 | } |
1da177e4 | 367 | |
1da177e4 LT |
368 | /* |
369 | * purge in-memory cell database on module unload or afs_init() failure | |
370 | * - the timeout daemon is stopped before calling this | |
371 | */ | |
372 | void afs_cell_purge(void) | |
373 | { | |
1da177e4 LT |
374 | struct afs_cell *cell; |
375 | ||
376 | _enter(""); | |
377 | ||
378 | afs_put_cell(afs_cell_root); | |
379 | ||
08e0e7c8 DH |
380 | down_write(&afs_cells_sem); |
381 | ||
1da177e4 LT |
382 | while (!list_empty(&afs_cells)) { |
383 | cell = NULL; | |
384 | ||
385 | /* remove the next cell from the front of the list */ | |
386 | write_lock(&afs_cells_lock); | |
387 | ||
388 | if (!list_empty(&afs_cells)) { | |
389 | cell = list_entry(afs_cells.next, | |
390 | struct afs_cell, link); | |
391 | list_del_init(&cell->link); | |
392 | } | |
393 | ||
394 | write_unlock(&afs_cells_lock); | |
395 | ||
396 | if (cell) { | |
397 | _debug("PURGING CELL %s (%d)", | |
398 | cell->name, atomic_read(&cell->usage)); | |
399 | ||
1da177e4 LT |
400 | /* now the cell should be left with no references */ |
401 | afs_cell_destroy(cell); | |
402 | } | |
403 | } | |
404 | ||
08e0e7c8 | 405 | up_write(&afs_cells_sem); |
1da177e4 | 406 | _leave(""); |
ec26815a | 407 | } |