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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 | ||
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 | ||
150 | #ifdef AFS_CACHING_SUPPORT | |
151 | /* put it up for caching */ | |
152 | cachefs_acquire_cookie(afs_cache_netfs.primary_index, | |
153 | &afs_vlocation_cache_index_def, | |
154 | cell, | |
155 | &cell->cache); | |
156 | #endif | |
157 | ||
158 | /* add to the cell lists */ | |
159 | write_lock(&afs_cells_lock); | |
160 | list_add_tail(&cell->link, &afs_cells); | |
161 | write_unlock(&afs_cells_lock); | |
162 | ||
163 | down_write(&afs_proc_cells_sem); | |
164 | list_add_tail(&cell->proc_link, &afs_proc_cells); | |
165 | up_write(&afs_proc_cells_sem); | |
1da177e4 LT |
166 | up_write(&afs_cells_sem); |
167 | ||
08e0e7c8 DH |
168 | _leave(" = %p", cell); |
169 | return cell; | |
1da177e4 | 170 | |
ec26815a | 171 | error: |
1da177e4 | 172 | up_write(&afs_cells_sem); |
00d3b7a4 | 173 | key_put(cell->anonymous_key); |
1da177e4 LT |
174 | kfree(cell); |
175 | _leave(" = %d", ret); | |
08e0e7c8 | 176 | return ERR_PTR(ret); |
5214b729 SS |
177 | |
178 | duplicate_name: | |
179 | read_unlock(&afs_cells_lock); | |
180 | up_write(&afs_cells_sem); | |
181 | return ERR_PTR(-EEXIST); | |
ec26815a | 182 | } |
1da177e4 | 183 | |
1da177e4 | 184 | /* |
08e0e7c8 DH |
185 | * set the root cell information |
186 | * - can be called with a module parameter string | |
187 | * - can be called from a write to /proc/fs/afs/rootcell | |
1da177e4 LT |
188 | */ |
189 | int afs_cell_init(char *rootcell) | |
190 | { | |
191 | struct afs_cell *old_root, *new_root; | |
192 | char *cp; | |
1da177e4 LT |
193 | |
194 | _enter(""); | |
195 | ||
196 | if (!rootcell) { | |
197 | /* module is loaded with no parameters, or built statically. | |
198 | * - in the future we might initialize cell DB here. | |
199 | */ | |
08e0e7c8 | 200 | _leave(" = 0 [no root]"); |
1da177e4 LT |
201 | return 0; |
202 | } | |
203 | ||
204 | cp = strchr(rootcell, ':'); | |
205 | if (!cp) { | |
206 | printk(KERN_ERR "kAFS: no VL server IP addresses specified\n"); | |
08e0e7c8 | 207 | _leave(" = -EINVAL"); |
1da177e4 LT |
208 | return -EINVAL; |
209 | } | |
210 | ||
211 | /* allocate a cell record for the root cell */ | |
212 | *cp++ = 0; | |
08e0e7c8 DH |
213 | new_root = afs_cell_create(rootcell, cp); |
214 | if (IS_ERR(new_root)) { | |
215 | _leave(" = %ld", PTR_ERR(new_root)); | |
216 | return PTR_ERR(new_root); | |
1da177e4 LT |
217 | } |
218 | ||
08e0e7c8 | 219 | /* install the new cell */ |
1da177e4 | 220 | write_lock(&afs_cells_lock); |
08e0e7c8 | 221 | old_root = afs_cell_root; |
1da177e4 LT |
222 | afs_cell_root = new_root; |
223 | write_unlock(&afs_cells_lock); | |
08e0e7c8 | 224 | afs_put_cell(old_root); |
1da177e4 | 225 | |
08e0e7c8 DH |
226 | _leave(" = 0"); |
227 | return 0; | |
ec26815a | 228 | } |
1da177e4 | 229 | |
1da177e4 LT |
230 | /* |
231 | * lookup a cell record | |
232 | */ | |
08e0e7c8 | 233 | struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz) |
1da177e4 LT |
234 | { |
235 | struct afs_cell *cell; | |
1da177e4 LT |
236 | |
237 | _enter("\"%*.*s\",", namesz, namesz, name ? name : ""); | |
238 | ||
08e0e7c8 DH |
239 | down_read(&afs_cells_sem); |
240 | read_lock(&afs_cells_lock); | |
1da177e4 LT |
241 | |
242 | if (name) { | |
243 | /* if the cell was named, look for it in the cell record list */ | |
1da177e4 LT |
244 | list_for_each_entry(cell, &afs_cells, link) { |
245 | if (strncmp(cell->name, name, namesz) == 0) { | |
246 | afs_get_cell(cell); | |
247 | goto found; | |
248 | } | |
249 | } | |
08e0e7c8 | 250 | cell = ERR_PTR(-ENOENT); |
1da177e4 | 251 | found: |
08e0e7c8 | 252 | ; |
ec26815a | 253 | } else { |
1da177e4 LT |
254 | cell = afs_cell_root; |
255 | if (!cell) { | |
256 | /* this should not happen unless user tries to mount | |
257 | * when root cell is not set. Return an impossibly | |
258 | * bizzare errno to alert the user. Things like | |
259 | * ENOENT might be "more appropriate" but they happen | |
260 | * for other reasons. | |
261 | */ | |
08e0e7c8 | 262 | cell = ERR_PTR(-EDESTADDRREQ); |
ec26815a | 263 | } else { |
1da177e4 | 264 | afs_get_cell(cell); |
1da177e4 LT |
265 | } |
266 | ||
1da177e4 LT |
267 | } |
268 | ||
08e0e7c8 DH |
269 | read_unlock(&afs_cells_lock); |
270 | up_read(&afs_cells_sem); | |
271 | _leave(" = %p", cell); | |
272 | return cell; | |
ec26815a | 273 | } |
1da177e4 | 274 | |
c1206a2c | 275 | #if 0 |
1da177e4 LT |
276 | /* |
277 | * try and get a cell record | |
278 | */ | |
08e0e7c8 | 279 | struct afs_cell *afs_get_cell_maybe(struct afs_cell *cell) |
1da177e4 | 280 | { |
1da177e4 LT |
281 | write_lock(&afs_cells_lock); |
282 | ||
1da177e4 LT |
283 | if (cell && !list_empty(&cell->link)) |
284 | afs_get_cell(cell); | |
285 | else | |
286 | cell = NULL; | |
287 | ||
288 | write_unlock(&afs_cells_lock); | |
1da177e4 | 289 | return cell; |
ec26815a | 290 | } |
c1206a2c | 291 | #endif /* 0 */ |
1da177e4 | 292 | |
1da177e4 LT |
293 | /* |
294 | * destroy a cell record | |
295 | */ | |
296 | void afs_put_cell(struct afs_cell *cell) | |
297 | { | |
298 | if (!cell) | |
299 | return; | |
300 | ||
301 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
302 | ||
08e0e7c8 | 303 | ASSERTCMP(atomic_read(&cell->usage), >, 0); |
1da177e4 LT |
304 | |
305 | /* to prevent a race, the decrement and the dequeue must be effectively | |
306 | * atomic */ | |
307 | write_lock(&afs_cells_lock); | |
308 | ||
309 | if (likely(!atomic_dec_and_test(&cell->usage))) { | |
310 | write_unlock(&afs_cells_lock); | |
311 | _leave(""); | |
312 | return; | |
313 | } | |
314 | ||
08e0e7c8 DH |
315 | ASSERT(list_empty(&cell->servers)); |
316 | ASSERT(list_empty(&cell->vl_list)); | |
317 | ||
1da177e4 LT |
318 | write_unlock(&afs_cells_lock); |
319 | ||
08e0e7c8 | 320 | wake_up(&afs_cells_freeable_wq); |
1da177e4 LT |
321 | |
322 | _leave(" [unused]"); | |
ec26815a | 323 | } |
1da177e4 | 324 | |
1da177e4 LT |
325 | /* |
326 | * destroy a cell record | |
08e0e7c8 DH |
327 | * - must be called with the afs_cells_sem write-locked |
328 | * - cell->link should have been broken by the caller | |
1da177e4 LT |
329 | */ |
330 | static void afs_cell_destroy(struct afs_cell *cell) | |
331 | { | |
332 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
333 | ||
08e0e7c8 DH |
334 | ASSERTCMP(atomic_read(&cell->usage), >=, 0); |
335 | ASSERT(list_empty(&cell->link)); | |
1da177e4 | 336 | |
08e0e7c8 DH |
337 | /* wait for everyone to stop using the cell */ |
338 | if (atomic_read(&cell->usage) > 0) { | |
339 | DECLARE_WAITQUEUE(myself, current); | |
1da177e4 | 340 | |
08e0e7c8 DH |
341 | _debug("wait for cell %s", cell->name); |
342 | set_current_state(TASK_UNINTERRUPTIBLE); | |
343 | add_wait_queue(&afs_cells_freeable_wq, &myself); | |
1da177e4 | 344 | |
08e0e7c8 DH |
345 | while (atomic_read(&cell->usage) > 0) { |
346 | schedule(); | |
347 | set_current_state(TASK_UNINTERRUPTIBLE); | |
348 | } | |
1da177e4 | 349 | |
08e0e7c8 DH |
350 | remove_wait_queue(&afs_cells_freeable_wq, &myself); |
351 | set_current_state(TASK_RUNNING); | |
352 | } | |
353 | ||
354 | _debug("cell dead"); | |
355 | ASSERTCMP(atomic_read(&cell->usage), ==, 0); | |
356 | ASSERT(list_empty(&cell->servers)); | |
357 | ASSERT(list_empty(&cell->vl_list)); | |
1da177e4 LT |
358 | |
359 | afs_proc_cell_remove(cell); | |
360 | ||
361 | down_write(&afs_proc_cells_sem); | |
362 | list_del_init(&cell->proc_link); | |
363 | up_write(&afs_proc_cells_sem); | |
364 | ||
365 | #ifdef AFS_CACHING_SUPPORT | |
366 | cachefs_relinquish_cookie(cell->cache, 0); | |
367 | #endif | |
368 | ||
00d3b7a4 | 369 | key_put(cell->anonymous_key); |
1da177e4 LT |
370 | kfree(cell); |
371 | ||
372 | _leave(" [destroyed]"); | |
ec26815a | 373 | } |
1da177e4 | 374 | |
1da177e4 LT |
375 | /* |
376 | * purge in-memory cell database on module unload or afs_init() failure | |
377 | * - the timeout daemon is stopped before calling this | |
378 | */ | |
379 | void afs_cell_purge(void) | |
380 | { | |
1da177e4 LT |
381 | struct afs_cell *cell; |
382 | ||
383 | _enter(""); | |
384 | ||
385 | afs_put_cell(afs_cell_root); | |
386 | ||
08e0e7c8 DH |
387 | down_write(&afs_cells_sem); |
388 | ||
1da177e4 LT |
389 | while (!list_empty(&afs_cells)) { |
390 | cell = NULL; | |
391 | ||
392 | /* remove the next cell from the front of the list */ | |
393 | write_lock(&afs_cells_lock); | |
394 | ||
395 | if (!list_empty(&afs_cells)) { | |
396 | cell = list_entry(afs_cells.next, | |
397 | struct afs_cell, link); | |
398 | list_del_init(&cell->link); | |
399 | } | |
400 | ||
401 | write_unlock(&afs_cells_lock); | |
402 | ||
403 | if (cell) { | |
404 | _debug("PURGING CELL %s (%d)", | |
405 | cell->name, atomic_read(&cell->usage)); | |
406 | ||
1da177e4 LT |
407 | /* now the cell should be left with no references */ |
408 | afs_cell_destroy(cell); | |
409 | } | |
410 | } | |
411 | ||
08e0e7c8 | 412 | up_write(&afs_cells_sem); |
1da177e4 | 413 | _leave(""); |
ec26815a | 414 | } |