Commit | Line | Data |
---|---|---|
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 | ||
0ae52d6f | 23 | static LIST_HEAD(afs_cells); |
1da177e4 LT |
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; | |
76181c13 | 36 | struct key *key; |
00d3b7a4 DH |
37 | size_t namelen; |
38 | char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp, *next; | |
1da177e4 LT |
39 | int ret; |
40 | ||
08e0e7c8 | 41 | _enter("%s,%s", name, vllist); |
1da177e4 LT |
42 | |
43 | BUG_ON(!name); /* TODO: want to look up "this cell" in the cache */ | |
44 | ||
00d3b7a4 DH |
45 | namelen = strlen(name); |
46 | if (namelen > AFS_MAXCELLNAME) | |
47 | return ERR_PTR(-ENAMETOOLONG); | |
48 | ||
1da177e4 | 49 | /* allocate and initialise a cell record */ |
00d3b7a4 | 50 | cell = kzalloc(sizeof(struct afs_cell) + namelen + 1, GFP_KERNEL); |
1da177e4 LT |
51 | if (!cell) { |
52 | _leave(" = -ENOMEM"); | |
08e0e7c8 | 53 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
54 | } |
55 | ||
00d3b7a4 DH |
56 | memcpy(cell->name, name, namelen); |
57 | cell->name[namelen] = 0; | |
1da177e4 | 58 | |
08e0e7c8 | 59 | atomic_set(&cell->usage, 1); |
1da177e4 | 60 | INIT_LIST_HEAD(&cell->link); |
08e0e7c8 DH |
61 | rwlock_init(&cell->servers_lock); |
62 | INIT_LIST_HEAD(&cell->servers); | |
1da177e4 LT |
63 | init_rwsem(&cell->vl_sem); |
64 | INIT_LIST_HEAD(&cell->vl_list); | |
08e0e7c8 | 65 | spin_lock_init(&cell->vl_lock); |
1da177e4 | 66 | |
1da177e4 | 67 | /* fill in the VL server list from the rest of the string */ |
1da177e4 LT |
68 | do { |
69 | unsigned a, b, c, d; | |
70 | ||
71 | next = strchr(vllist, ':'); | |
72 | if (next) | |
73 | *next++ = 0; | |
74 | ||
75 | if (sscanf(vllist, "%u.%u.%u.%u", &a, &b, &c, &d) != 4) | |
00d3b7a4 | 76 | goto bad_address; |
1da177e4 LT |
77 | |
78 | if (a > 255 || b > 255 || c > 255 || d > 255) | |
00d3b7a4 | 79 | goto bad_address; |
1da177e4 LT |
80 | |
81 | cell->vl_addrs[cell->vl_naddrs++].s_addr = | |
82 | htonl((a << 24) | (b << 16) | (c << 8) | d); | |
83 | ||
00d3b7a4 DH |
84 | } while (cell->vl_naddrs < AFS_CELL_MAX_ADDRS && (vllist = next)); |
85 | ||
86 | /* create a key to represent an anonymous user */ | |
87 | memcpy(keyname, "afs@", 4); | |
88 | dp = keyname + 4; | |
89 | cp = cell->name; | |
90 | do { | |
91 | *dp++ = toupper(*cp); | |
92 | } while (*cp++); | |
00d3b7a4 | 93 | |
76181c13 DH |
94 | key = rxrpc_get_null_key(keyname); |
95 | if (IS_ERR(key)) { | |
96 | _debug("no key"); | |
97 | ret = PTR_ERR(key); | |
00d3b7a4 DH |
98 | goto error; |
99 | } | |
76181c13 | 100 | cell->anonymous_key = key; |
00d3b7a4 DH |
101 | |
102 | _debug("anon key %p{%x}", | |
103 | cell->anonymous_key, key_serial(cell->anonymous_key)); | |
104 | ||
105 | _leave(" = %p", cell); | |
106 | return cell; | |
107 | ||
108 | bad_address: | |
109 | printk(KERN_ERR "kAFS: bad VL server IP address\n"); | |
110 | ret = -EINVAL; | |
111 | error: | |
112 | key_put(cell->anonymous_key); | |
113 | kfree(cell); | |
114 | _leave(" = %d", ret); | |
115 | return ERR_PTR(ret); | |
116 | } | |
1da177e4 | 117 | |
00d3b7a4 DH |
118 | /* |
119 | * create a cell record | |
120 | * - "name" is the name of the cell | |
121 | * - "vllist" is a colon separated list of IP addresses in "a.b.c.d" format | |
122 | */ | |
123 | struct afs_cell *afs_cell_create(const char *name, char *vllist) | |
124 | { | |
125 | struct afs_cell *cell; | |
126 | int ret; | |
127 | ||
128 | _enter("%s,%s", name, vllist); | |
129 | ||
5214b729 SS |
130 | down_write(&afs_cells_sem); |
131 | read_lock(&afs_cells_lock); | |
132 | list_for_each_entry(cell, &afs_cells, link) { | |
133 | if (strcasecmp(cell->name, name) == 0) | |
134 | goto duplicate_name; | |
135 | } | |
136 | read_unlock(&afs_cells_lock); | |
137 | ||
00d3b7a4 DH |
138 | cell = afs_cell_alloc(name, vllist); |
139 | if (IS_ERR(cell)) { | |
140 | _leave(" = %ld", PTR_ERR(cell)); | |
a5f37c32 | 141 | up_write(&afs_cells_sem); |
00d3b7a4 DH |
142 | return cell; |
143 | } | |
144 | ||
08e0e7c8 | 145 | /* add a proc directory for this cell */ |
1da177e4 LT |
146 | ret = afs_proc_cell_setup(cell); |
147 | if (ret < 0) | |
148 | goto error; | |
149 | ||
9b3f26c9 DH |
150 | #ifdef CONFIG_AFS_FSCACHE |
151 | /* put it up for caching (this never returns an error) */ | |
152 | cell->cache = fscache_acquire_cookie(afs_cache_netfs.primary_index, | |
153 | &afs_cell_cache_index_def, | |
154 | cell); | |
1da177e4 LT |
155 | #endif |
156 | ||
157 | /* add to the cell lists */ | |
158 | write_lock(&afs_cells_lock); | |
159 | list_add_tail(&cell->link, &afs_cells); | |
160 | write_unlock(&afs_cells_lock); | |
161 | ||
162 | down_write(&afs_proc_cells_sem); | |
163 | list_add_tail(&cell->proc_link, &afs_proc_cells); | |
164 | up_write(&afs_proc_cells_sem); | |
1da177e4 LT |
165 | up_write(&afs_cells_sem); |
166 | ||
08e0e7c8 DH |
167 | _leave(" = %p", cell); |
168 | return cell; | |
1da177e4 | 169 | |
ec26815a | 170 | error: |
1da177e4 | 171 | up_write(&afs_cells_sem); |
00d3b7a4 | 172 | key_put(cell->anonymous_key); |
1da177e4 LT |
173 | kfree(cell); |
174 | _leave(" = %d", ret); | |
08e0e7c8 | 175 | return ERR_PTR(ret); |
5214b729 SS |
176 | |
177 | duplicate_name: | |
178 | read_unlock(&afs_cells_lock); | |
179 | up_write(&afs_cells_sem); | |
180 | return ERR_PTR(-EEXIST); | |
ec26815a | 181 | } |
1da177e4 | 182 | |
1da177e4 | 183 | /* |
08e0e7c8 DH |
184 | * set the root cell information |
185 | * - can be called with a module parameter string | |
186 | * - can be called from a write to /proc/fs/afs/rootcell | |
1da177e4 LT |
187 | */ |
188 | int afs_cell_init(char *rootcell) | |
189 | { | |
190 | struct afs_cell *old_root, *new_root; | |
191 | char *cp; | |
1da177e4 LT |
192 | |
193 | _enter(""); | |
194 | ||
195 | if (!rootcell) { | |
196 | /* module is loaded with no parameters, or built statically. | |
197 | * - in the future we might initialize cell DB here. | |
198 | */ | |
08e0e7c8 | 199 | _leave(" = 0 [no root]"); |
1da177e4 LT |
200 | return 0; |
201 | } | |
202 | ||
203 | cp = strchr(rootcell, ':'); | |
204 | if (!cp) { | |
205 | printk(KERN_ERR "kAFS: no VL server IP addresses specified\n"); | |
08e0e7c8 | 206 | _leave(" = -EINVAL"); |
1da177e4 LT |
207 | return -EINVAL; |
208 | } | |
209 | ||
210 | /* allocate a cell record for the root cell */ | |
211 | *cp++ = 0; | |
08e0e7c8 DH |
212 | new_root = afs_cell_create(rootcell, cp); |
213 | if (IS_ERR(new_root)) { | |
214 | _leave(" = %ld", PTR_ERR(new_root)); | |
215 | return PTR_ERR(new_root); | |
1da177e4 LT |
216 | } |
217 | ||
08e0e7c8 | 218 | /* install the new cell */ |
1da177e4 | 219 | write_lock(&afs_cells_lock); |
08e0e7c8 | 220 | old_root = afs_cell_root; |
1da177e4 LT |
221 | afs_cell_root = new_root; |
222 | write_unlock(&afs_cells_lock); | |
08e0e7c8 | 223 | afs_put_cell(old_root); |
1da177e4 | 224 | |
08e0e7c8 DH |
225 | _leave(" = 0"); |
226 | return 0; | |
ec26815a | 227 | } |
1da177e4 | 228 | |
1da177e4 LT |
229 | /* |
230 | * lookup a cell record | |
231 | */ | |
08e0e7c8 | 232 | struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz) |
1da177e4 LT |
233 | { |
234 | struct afs_cell *cell; | |
1da177e4 LT |
235 | |
236 | _enter("\"%*.*s\",", namesz, namesz, name ? name : ""); | |
237 | ||
08e0e7c8 DH |
238 | down_read(&afs_cells_sem); |
239 | read_lock(&afs_cells_lock); | |
1da177e4 LT |
240 | |
241 | if (name) { | |
242 | /* if the cell was named, look for it in the cell record list */ | |
1da177e4 LT |
243 | list_for_each_entry(cell, &afs_cells, link) { |
244 | if (strncmp(cell->name, name, namesz) == 0) { | |
245 | afs_get_cell(cell); | |
246 | goto found; | |
247 | } | |
248 | } | |
08e0e7c8 | 249 | cell = ERR_PTR(-ENOENT); |
1da177e4 | 250 | found: |
08e0e7c8 | 251 | ; |
ec26815a | 252 | } else { |
1da177e4 LT |
253 | cell = afs_cell_root; |
254 | if (!cell) { | |
255 | /* this should not happen unless user tries to mount | |
256 | * when root cell is not set. Return an impossibly | |
257 | * bizzare errno to alert the user. Things like | |
258 | * ENOENT might be "more appropriate" but they happen | |
259 | * for other reasons. | |
260 | */ | |
08e0e7c8 | 261 | cell = ERR_PTR(-EDESTADDRREQ); |
ec26815a | 262 | } else { |
1da177e4 | 263 | afs_get_cell(cell); |
1da177e4 LT |
264 | } |
265 | ||
1da177e4 LT |
266 | } |
267 | ||
08e0e7c8 DH |
268 | read_unlock(&afs_cells_lock); |
269 | up_read(&afs_cells_sem); | |
270 | _leave(" = %p", cell); | |
271 | return cell; | |
ec26815a | 272 | } |
1da177e4 | 273 | |
c1206a2c | 274 | #if 0 |
1da177e4 LT |
275 | /* |
276 | * try and get a cell record | |
277 | */ | |
08e0e7c8 | 278 | struct afs_cell *afs_get_cell_maybe(struct afs_cell *cell) |
1da177e4 | 279 | { |
1da177e4 LT |
280 | write_lock(&afs_cells_lock); |
281 | ||
1da177e4 LT |
282 | if (cell && !list_empty(&cell->link)) |
283 | afs_get_cell(cell); | |
284 | else | |
285 | cell = NULL; | |
286 | ||
287 | write_unlock(&afs_cells_lock); | |
1da177e4 | 288 | return cell; |
ec26815a | 289 | } |
c1206a2c | 290 | #endif /* 0 */ |
1da177e4 | 291 | |
1da177e4 LT |
292 | /* |
293 | * destroy a cell record | |
294 | */ | |
295 | void afs_put_cell(struct afs_cell *cell) | |
296 | { | |
297 | if (!cell) | |
298 | return; | |
299 | ||
300 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
301 | ||
08e0e7c8 | 302 | ASSERTCMP(atomic_read(&cell->usage), >, 0); |
1da177e4 LT |
303 | |
304 | /* to prevent a race, the decrement and the dequeue must be effectively | |
305 | * atomic */ | |
306 | write_lock(&afs_cells_lock); | |
307 | ||
308 | if (likely(!atomic_dec_and_test(&cell->usage))) { | |
309 | write_unlock(&afs_cells_lock); | |
310 | _leave(""); | |
311 | return; | |
312 | } | |
313 | ||
08e0e7c8 DH |
314 | ASSERT(list_empty(&cell->servers)); |
315 | ASSERT(list_empty(&cell->vl_list)); | |
316 | ||
1da177e4 LT |
317 | write_unlock(&afs_cells_lock); |
318 | ||
08e0e7c8 | 319 | wake_up(&afs_cells_freeable_wq); |
1da177e4 LT |
320 | |
321 | _leave(" [unused]"); | |
ec26815a | 322 | } |
1da177e4 | 323 | |
1da177e4 LT |
324 | /* |
325 | * destroy a cell record | |
08e0e7c8 DH |
326 | * - must be called with the afs_cells_sem write-locked |
327 | * - cell->link should have been broken by the caller | |
1da177e4 LT |
328 | */ |
329 | static void afs_cell_destroy(struct afs_cell *cell) | |
330 | { | |
331 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
332 | ||
08e0e7c8 DH |
333 | ASSERTCMP(atomic_read(&cell->usage), >=, 0); |
334 | ASSERT(list_empty(&cell->link)); | |
1da177e4 | 335 | |
08e0e7c8 DH |
336 | /* wait for everyone to stop using the cell */ |
337 | if (atomic_read(&cell->usage) > 0) { | |
338 | DECLARE_WAITQUEUE(myself, current); | |
1da177e4 | 339 | |
08e0e7c8 DH |
340 | _debug("wait for cell %s", cell->name); |
341 | set_current_state(TASK_UNINTERRUPTIBLE); | |
342 | add_wait_queue(&afs_cells_freeable_wq, &myself); | |
1da177e4 | 343 | |
08e0e7c8 DH |
344 | while (atomic_read(&cell->usage) > 0) { |
345 | schedule(); | |
346 | set_current_state(TASK_UNINTERRUPTIBLE); | |
347 | } | |
1da177e4 | 348 | |
08e0e7c8 DH |
349 | remove_wait_queue(&afs_cells_freeable_wq, &myself); |
350 | set_current_state(TASK_RUNNING); | |
351 | } | |
352 | ||
353 | _debug("cell dead"); | |
354 | ASSERTCMP(atomic_read(&cell->usage), ==, 0); | |
355 | ASSERT(list_empty(&cell->servers)); | |
356 | ASSERT(list_empty(&cell->vl_list)); | |
1da177e4 LT |
357 | |
358 | afs_proc_cell_remove(cell); | |
359 | ||
360 | down_write(&afs_proc_cells_sem); | |
361 | list_del_init(&cell->proc_link); | |
362 | up_write(&afs_proc_cells_sem); | |
363 | ||
9b3f26c9 DH |
364 | #ifdef CONFIG_AFS_FSCACHE |
365 | fscache_relinquish_cookie(cell->cache, 0); | |
1da177e4 | 366 | #endif |
00d3b7a4 | 367 | key_put(cell->anonymous_key); |
1da177e4 LT |
368 | kfree(cell); |
369 | ||
370 | _leave(" [destroyed]"); | |
ec26815a | 371 | } |
1da177e4 | 372 | |
1da177e4 LT |
373 | /* |
374 | * purge in-memory cell database on module unload or afs_init() failure | |
375 | * - the timeout daemon is stopped before calling this | |
376 | */ | |
377 | void afs_cell_purge(void) | |
378 | { | |
1da177e4 LT |
379 | struct afs_cell *cell; |
380 | ||
381 | _enter(""); | |
382 | ||
383 | afs_put_cell(afs_cell_root); | |
384 | ||
08e0e7c8 DH |
385 | down_write(&afs_cells_sem); |
386 | ||
1da177e4 LT |
387 | while (!list_empty(&afs_cells)) { |
388 | cell = NULL; | |
389 | ||
390 | /* remove the next cell from the front of the list */ | |
391 | write_lock(&afs_cells_lock); | |
392 | ||
393 | if (!list_empty(&afs_cells)) { | |
394 | cell = list_entry(afs_cells.next, | |
395 | struct afs_cell, link); | |
396 | list_del_init(&cell->link); | |
397 | } | |
398 | ||
399 | write_unlock(&afs_cells_lock); | |
400 | ||
401 | if (cell) { | |
402 | _debug("PURGING CELL %s (%d)", | |
403 | cell->name, atomic_read(&cell->usage)); | |
404 | ||
1da177e4 LT |
405 | /* now the cell should be left with no references */ |
406 | afs_cell_destroy(cell); | |
407 | } | |
408 | } | |
409 | ||
08e0e7c8 | 410 | up_write(&afs_cells_sem); |
1da177e4 | 411 | _leave(""); |
ec26815a | 412 | } |