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 | ||
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; | |
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 | ||
130 | cell = afs_cell_alloc(name, vllist); | |
131 | if (IS_ERR(cell)) { | |
132 | _leave(" = %ld", PTR_ERR(cell)); | |
133 | return cell; | |
134 | } | |
135 | ||
136 | down_write(&afs_cells_sem); | |
1da177e4 | 137 | |
08e0e7c8 | 138 | /* add a proc directory for this cell */ |
1da177e4 LT |
139 | ret = afs_proc_cell_setup(cell); |
140 | if (ret < 0) | |
141 | goto error; | |
142 | ||
143 | #ifdef AFS_CACHING_SUPPORT | |
144 | /* put it up for caching */ | |
145 | cachefs_acquire_cookie(afs_cache_netfs.primary_index, | |
146 | &afs_vlocation_cache_index_def, | |
147 | cell, | |
148 | &cell->cache); | |
149 | #endif | |
150 | ||
151 | /* add to the cell lists */ | |
152 | write_lock(&afs_cells_lock); | |
153 | list_add_tail(&cell->link, &afs_cells); | |
154 | write_unlock(&afs_cells_lock); | |
155 | ||
156 | down_write(&afs_proc_cells_sem); | |
157 | list_add_tail(&cell->proc_link, &afs_proc_cells); | |
158 | up_write(&afs_proc_cells_sem); | |
1da177e4 LT |
159 | up_write(&afs_cells_sem); |
160 | ||
08e0e7c8 DH |
161 | _leave(" = %p", cell); |
162 | return cell; | |
1da177e4 | 163 | |
ec26815a | 164 | error: |
1da177e4 | 165 | up_write(&afs_cells_sem); |
00d3b7a4 | 166 | key_put(cell->anonymous_key); |
1da177e4 LT |
167 | kfree(cell); |
168 | _leave(" = %d", ret); | |
08e0e7c8 | 169 | return ERR_PTR(ret); |
ec26815a | 170 | } |
1da177e4 | 171 | |
1da177e4 | 172 | /* |
08e0e7c8 DH |
173 | * set the root cell information |
174 | * - can be called with a module parameter string | |
175 | * - can be called from a write to /proc/fs/afs/rootcell | |
1da177e4 LT |
176 | */ |
177 | int afs_cell_init(char *rootcell) | |
178 | { | |
179 | struct afs_cell *old_root, *new_root; | |
180 | char *cp; | |
1da177e4 LT |
181 | |
182 | _enter(""); | |
183 | ||
184 | if (!rootcell) { | |
185 | /* module is loaded with no parameters, or built statically. | |
186 | * - in the future we might initialize cell DB here. | |
187 | */ | |
08e0e7c8 | 188 | _leave(" = 0 [no root]"); |
1da177e4 LT |
189 | return 0; |
190 | } | |
191 | ||
192 | cp = strchr(rootcell, ':'); | |
193 | if (!cp) { | |
194 | printk(KERN_ERR "kAFS: no VL server IP addresses specified\n"); | |
08e0e7c8 | 195 | _leave(" = -EINVAL"); |
1da177e4 LT |
196 | return -EINVAL; |
197 | } | |
198 | ||
199 | /* allocate a cell record for the root cell */ | |
200 | *cp++ = 0; | |
08e0e7c8 DH |
201 | new_root = afs_cell_create(rootcell, cp); |
202 | if (IS_ERR(new_root)) { | |
203 | _leave(" = %ld", PTR_ERR(new_root)); | |
204 | return PTR_ERR(new_root); | |
1da177e4 LT |
205 | } |
206 | ||
08e0e7c8 | 207 | /* install the new cell */ |
1da177e4 | 208 | write_lock(&afs_cells_lock); |
08e0e7c8 | 209 | old_root = afs_cell_root; |
1da177e4 LT |
210 | afs_cell_root = new_root; |
211 | write_unlock(&afs_cells_lock); | |
08e0e7c8 | 212 | afs_put_cell(old_root); |
1da177e4 | 213 | |
08e0e7c8 DH |
214 | _leave(" = 0"); |
215 | return 0; | |
ec26815a | 216 | } |
1da177e4 | 217 | |
1da177e4 LT |
218 | /* |
219 | * lookup a cell record | |
220 | */ | |
08e0e7c8 | 221 | struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz) |
1da177e4 LT |
222 | { |
223 | struct afs_cell *cell; | |
1da177e4 LT |
224 | |
225 | _enter("\"%*.*s\",", namesz, namesz, name ? name : ""); | |
226 | ||
08e0e7c8 DH |
227 | down_read(&afs_cells_sem); |
228 | read_lock(&afs_cells_lock); | |
1da177e4 LT |
229 | |
230 | if (name) { | |
231 | /* if the cell was named, look for it in the cell record list */ | |
1da177e4 LT |
232 | list_for_each_entry(cell, &afs_cells, link) { |
233 | if (strncmp(cell->name, name, namesz) == 0) { | |
234 | afs_get_cell(cell); | |
235 | goto found; | |
236 | } | |
237 | } | |
08e0e7c8 | 238 | cell = ERR_PTR(-ENOENT); |
1da177e4 | 239 | found: |
08e0e7c8 | 240 | ; |
ec26815a | 241 | } else { |
1da177e4 LT |
242 | cell = afs_cell_root; |
243 | if (!cell) { | |
244 | /* this should not happen unless user tries to mount | |
245 | * when root cell is not set. Return an impossibly | |
246 | * bizzare errno to alert the user. Things like | |
247 | * ENOENT might be "more appropriate" but they happen | |
248 | * for other reasons. | |
249 | */ | |
08e0e7c8 | 250 | cell = ERR_PTR(-EDESTADDRREQ); |
ec26815a | 251 | } else { |
1da177e4 | 252 | afs_get_cell(cell); |
1da177e4 LT |
253 | } |
254 | ||
1da177e4 LT |
255 | } |
256 | ||
08e0e7c8 DH |
257 | read_unlock(&afs_cells_lock); |
258 | up_read(&afs_cells_sem); | |
259 | _leave(" = %p", cell); | |
260 | return cell; | |
ec26815a | 261 | } |
1da177e4 | 262 | |
c1206a2c | 263 | #if 0 |
1da177e4 LT |
264 | /* |
265 | * try and get a cell record | |
266 | */ | |
08e0e7c8 | 267 | struct afs_cell *afs_get_cell_maybe(struct afs_cell *cell) |
1da177e4 | 268 | { |
1da177e4 LT |
269 | write_lock(&afs_cells_lock); |
270 | ||
1da177e4 LT |
271 | if (cell && !list_empty(&cell->link)) |
272 | afs_get_cell(cell); | |
273 | else | |
274 | cell = NULL; | |
275 | ||
276 | write_unlock(&afs_cells_lock); | |
1da177e4 | 277 | return cell; |
ec26815a | 278 | } |
c1206a2c | 279 | #endif /* 0 */ |
1da177e4 | 280 | |
1da177e4 LT |
281 | /* |
282 | * destroy a cell record | |
283 | */ | |
284 | void afs_put_cell(struct afs_cell *cell) | |
285 | { | |
286 | if (!cell) | |
287 | return; | |
288 | ||
289 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
290 | ||
08e0e7c8 | 291 | ASSERTCMP(atomic_read(&cell->usage), >, 0); |
1da177e4 LT |
292 | |
293 | /* to prevent a race, the decrement and the dequeue must be effectively | |
294 | * atomic */ | |
295 | write_lock(&afs_cells_lock); | |
296 | ||
297 | if (likely(!atomic_dec_and_test(&cell->usage))) { | |
298 | write_unlock(&afs_cells_lock); | |
299 | _leave(""); | |
300 | return; | |
301 | } | |
302 | ||
08e0e7c8 DH |
303 | ASSERT(list_empty(&cell->servers)); |
304 | ASSERT(list_empty(&cell->vl_list)); | |
305 | ||
1da177e4 LT |
306 | write_unlock(&afs_cells_lock); |
307 | ||
08e0e7c8 | 308 | wake_up(&afs_cells_freeable_wq); |
1da177e4 LT |
309 | |
310 | _leave(" [unused]"); | |
ec26815a | 311 | } |
1da177e4 | 312 | |
1da177e4 LT |
313 | /* |
314 | * destroy a cell record | |
08e0e7c8 DH |
315 | * - must be called with the afs_cells_sem write-locked |
316 | * - cell->link should have been broken by the caller | |
1da177e4 LT |
317 | */ |
318 | static void afs_cell_destroy(struct afs_cell *cell) | |
319 | { | |
320 | _enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name); | |
321 | ||
08e0e7c8 DH |
322 | ASSERTCMP(atomic_read(&cell->usage), >=, 0); |
323 | ASSERT(list_empty(&cell->link)); | |
1da177e4 | 324 | |
08e0e7c8 DH |
325 | /* wait for everyone to stop using the cell */ |
326 | if (atomic_read(&cell->usage) > 0) { | |
327 | DECLARE_WAITQUEUE(myself, current); | |
1da177e4 | 328 | |
08e0e7c8 DH |
329 | _debug("wait for cell %s", cell->name); |
330 | set_current_state(TASK_UNINTERRUPTIBLE); | |
331 | add_wait_queue(&afs_cells_freeable_wq, &myself); | |
1da177e4 | 332 | |
08e0e7c8 DH |
333 | while (atomic_read(&cell->usage) > 0) { |
334 | schedule(); | |
335 | set_current_state(TASK_UNINTERRUPTIBLE); | |
336 | } | |
1da177e4 | 337 | |
08e0e7c8 DH |
338 | remove_wait_queue(&afs_cells_freeable_wq, &myself); |
339 | set_current_state(TASK_RUNNING); | |
340 | } | |
341 | ||
342 | _debug("cell dead"); | |
343 | ASSERTCMP(atomic_read(&cell->usage), ==, 0); | |
344 | ASSERT(list_empty(&cell->servers)); | |
345 | ASSERT(list_empty(&cell->vl_list)); | |
1da177e4 LT |
346 | |
347 | afs_proc_cell_remove(cell); | |
348 | ||
349 | down_write(&afs_proc_cells_sem); | |
350 | list_del_init(&cell->proc_link); | |
351 | up_write(&afs_proc_cells_sem); | |
352 | ||
353 | #ifdef AFS_CACHING_SUPPORT | |
354 | cachefs_relinquish_cookie(cell->cache, 0); | |
355 | #endif | |
356 | ||
00d3b7a4 | 357 | key_put(cell->anonymous_key); |
1da177e4 LT |
358 | kfree(cell); |
359 | ||
360 | _leave(" [destroyed]"); | |
ec26815a | 361 | } |
1da177e4 | 362 | |
1da177e4 LT |
363 | /* |
364 | * purge in-memory cell database on module unload or afs_init() failure | |
365 | * - the timeout daemon is stopped before calling this | |
366 | */ | |
367 | void afs_cell_purge(void) | |
368 | { | |
1da177e4 LT |
369 | struct afs_cell *cell; |
370 | ||
371 | _enter(""); | |
372 | ||
373 | afs_put_cell(afs_cell_root); | |
374 | ||
08e0e7c8 DH |
375 | down_write(&afs_cells_sem); |
376 | ||
1da177e4 LT |
377 | while (!list_empty(&afs_cells)) { |
378 | cell = NULL; | |
379 | ||
380 | /* remove the next cell from the front of the list */ | |
381 | write_lock(&afs_cells_lock); | |
382 | ||
383 | if (!list_empty(&afs_cells)) { | |
384 | cell = list_entry(afs_cells.next, | |
385 | struct afs_cell, link); | |
386 | list_del_init(&cell->link); | |
387 | } | |
388 | ||
389 | write_unlock(&afs_cells_lock); | |
390 | ||
391 | if (cell) { | |
392 | _debug("PURGING CELL %s (%d)", | |
393 | cell->name, atomic_read(&cell->usage)); | |
394 | ||
1da177e4 LT |
395 | /* now the cell should be left with no references */ |
396 | afs_cell_destroy(cell); | |
397 | } | |
398 | } | |
399 | ||
08e0e7c8 | 400 | up_write(&afs_cells_sem); |
1da177e4 | 401 | _leave(""); |
ec26815a | 402 | } |