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1 | /* | |
2 | * linux/fs/9p/v9fs.c | |
3 | * | |
4 | * This file contains functions assisting in mapping VFS to 9P2000 | |
5 | * | |
6 | * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com> | |
7 | * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 | |
11 | * as published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to: | |
20 | * Free Software Foundation | |
21 | * 51 Franklin Street, Fifth Floor | |
22 | * Boston, MA 02111-1301 USA | |
23 | * | |
24 | */ | |
25 | ||
26 | #include <linux/module.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/fs.h> | |
29 | #include <linux/sched.h> | |
30 | #include <linux/parser.h> | |
31 | #include <linux/idr.h> | |
32 | #include <linux/slab.h> | |
33 | #include <net/9p/9p.h> | |
34 | #include <net/9p/client.h> | |
35 | #include <net/9p/transport.h> | |
36 | #include "v9fs.h" | |
37 | #include "v9fs_vfs.h" | |
38 | #include "cache.h" | |
39 | ||
40 | static DEFINE_SPINLOCK(v9fs_sessionlist_lock); | |
41 | static LIST_HEAD(v9fs_sessionlist); | |
42 | ||
43 | /* | |
44 | * Option Parsing (code inspired by NFS code) | |
45 | * NOTE: each transport will parse its own options | |
46 | */ | |
47 | ||
48 | enum { | |
49 | /* Options that take integer arguments */ | |
50 | Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid, | |
51 | /* String options */ | |
52 | Opt_uname, Opt_remotename, Opt_trans, Opt_cache, Opt_cachetag, | |
53 | /* Options that take no arguments */ | |
54 | Opt_nodevmap, | |
55 | /* Cache options */ | |
56 | Opt_cache_loose, Opt_fscache, | |
57 | /* Access options */ | |
58 | Opt_access, | |
59 | /* Error token */ | |
60 | Opt_err | |
61 | }; | |
62 | ||
63 | static const match_table_t tokens = { | |
64 | {Opt_debug, "debug=%x"}, | |
65 | {Opt_dfltuid, "dfltuid=%u"}, | |
66 | {Opt_dfltgid, "dfltgid=%u"}, | |
67 | {Opt_afid, "afid=%u"}, | |
68 | {Opt_uname, "uname=%s"}, | |
69 | {Opt_remotename, "aname=%s"}, | |
70 | {Opt_nodevmap, "nodevmap"}, | |
71 | {Opt_cache, "cache=%s"}, | |
72 | {Opt_cache_loose, "loose"}, | |
73 | {Opt_fscache, "fscache"}, | |
74 | {Opt_cachetag, "cachetag=%s"}, | |
75 | {Opt_access, "access=%s"}, | |
76 | {Opt_err, NULL} | |
77 | }; | |
78 | ||
79 | /** | |
80 | * v9fs_parse_options - parse mount options into session structure | |
81 | * @v9ses: existing v9fs session information | |
82 | * | |
83 | * Return 0 upon success, -ERRNO upon failure. | |
84 | */ | |
85 | ||
86 | static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts) | |
87 | { | |
88 | char *options, *tmp_options; | |
89 | substring_t args[MAX_OPT_ARGS]; | |
90 | char *p; | |
91 | int option = 0; | |
92 | char *s, *e; | |
93 | int ret = 0; | |
94 | ||
95 | /* setup defaults */ | |
96 | v9ses->afid = ~0; | |
97 | v9ses->debug = 0; | |
98 | v9ses->cache = 0; | |
99 | #ifdef CONFIG_9P_FSCACHE | |
100 | v9ses->cachetag = NULL; | |
101 | #endif | |
102 | ||
103 | if (!opts) | |
104 | return 0; | |
105 | ||
106 | tmp_options = kstrdup(opts, GFP_KERNEL); | |
107 | if (!tmp_options) { | |
108 | ret = -ENOMEM; | |
109 | goto fail_option_alloc; | |
110 | } | |
111 | options = tmp_options; | |
112 | ||
113 | while ((p = strsep(&options, ",")) != NULL) { | |
114 | int token; | |
115 | if (!*p) | |
116 | continue; | |
117 | token = match_token(p, tokens, args); | |
118 | if (token < Opt_uname) { | |
119 | int r = match_int(&args[0], &option); | |
120 | if (r < 0) { | |
121 | P9_DPRINTK(P9_DEBUG_ERROR, | |
122 | "integer field, but no integer?\n"); | |
123 | ret = r; | |
124 | continue; | |
125 | } | |
126 | } | |
127 | switch (token) { | |
128 | case Opt_debug: | |
129 | v9ses->debug = option; | |
130 | #ifdef CONFIG_NET_9P_DEBUG | |
131 | p9_debug_level = option; | |
132 | #endif | |
133 | break; | |
134 | ||
135 | case Opt_dfltuid: | |
136 | v9ses->dfltuid = option; | |
137 | break; | |
138 | case Opt_dfltgid: | |
139 | v9ses->dfltgid = option; | |
140 | break; | |
141 | case Opt_afid: | |
142 | v9ses->afid = option; | |
143 | break; | |
144 | case Opt_uname: | |
145 | match_strlcpy(v9ses->uname, &args[0], PATH_MAX); | |
146 | break; | |
147 | case Opt_remotename: | |
148 | match_strlcpy(v9ses->aname, &args[0], PATH_MAX); | |
149 | break; | |
150 | case Opt_nodevmap: | |
151 | v9ses->nodev = 1; | |
152 | break; | |
153 | case Opt_cache_loose: | |
154 | v9ses->cache = CACHE_LOOSE; | |
155 | break; | |
156 | case Opt_fscache: | |
157 | v9ses->cache = CACHE_FSCACHE; | |
158 | break; | |
159 | case Opt_cachetag: | |
160 | #ifdef CONFIG_9P_FSCACHE | |
161 | v9ses->cachetag = match_strdup(&args[0]); | |
162 | #endif | |
163 | break; | |
164 | case Opt_cache: | |
165 | s = match_strdup(&args[0]); | |
166 | if (!s) { | |
167 | ret = -ENOMEM; | |
168 | P9_DPRINTK(P9_DEBUG_ERROR, | |
169 | "problem allocating copy of cache arg\n"); | |
170 | goto free_and_return; | |
171 | } | |
172 | ||
173 | if (strcmp(s, "loose") == 0) | |
174 | v9ses->cache = CACHE_LOOSE; | |
175 | else if (strcmp(s, "fscache") == 0) | |
176 | v9ses->cache = CACHE_FSCACHE; | |
177 | else | |
178 | v9ses->cache = CACHE_NONE; | |
179 | kfree(s); | |
180 | break; | |
181 | ||
182 | case Opt_access: | |
183 | s = match_strdup(&args[0]); | |
184 | if (!s) { | |
185 | ret = -ENOMEM; | |
186 | P9_DPRINTK(P9_DEBUG_ERROR, | |
187 | "problem allocating copy of access arg\n"); | |
188 | goto free_and_return; | |
189 | } | |
190 | ||
191 | v9ses->flags &= ~V9FS_ACCESS_MASK; | |
192 | if (strcmp(s, "user") == 0) | |
193 | v9ses->flags |= V9FS_ACCESS_USER; | |
194 | else if (strcmp(s, "any") == 0) | |
195 | v9ses->flags |= V9FS_ACCESS_ANY; | |
196 | else if (strcmp(s, "client") == 0) { | |
197 | #ifdef CONFIG_9P_FS_POSIX_ACL | |
198 | v9ses->flags |= V9FS_ACCESS_CLIENT; | |
199 | #else | |
200 | P9_DPRINTK(P9_DEBUG_ERROR, | |
201 | "access=client option not supported\n"); | |
202 | kfree(s); | |
203 | ret = -EINVAL; | |
204 | goto free_and_return; | |
205 | #endif | |
206 | } else { | |
207 | v9ses->flags |= V9FS_ACCESS_SINGLE; | |
208 | v9ses->uid = simple_strtoul(s, &e, 10); | |
209 | if (*e != '\0') | |
210 | v9ses->uid = ~0; | |
211 | } | |
212 | kfree(s); | |
213 | break; | |
214 | ||
215 | default: | |
216 | continue; | |
217 | } | |
218 | } | |
219 | ||
220 | free_and_return: | |
221 | kfree(tmp_options); | |
222 | fail_option_alloc: | |
223 | return ret; | |
224 | } | |
225 | ||
226 | /** | |
227 | * v9fs_session_init - initialize session | |
228 | * @v9ses: session information structure | |
229 | * @dev_name: device being mounted | |
230 | * @data: options | |
231 | * | |
232 | */ | |
233 | ||
234 | struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses, | |
235 | const char *dev_name, char *data) | |
236 | { | |
237 | int retval = -EINVAL; | |
238 | struct p9_fid *fid; | |
239 | int rc; | |
240 | ||
241 | v9ses->uname = __getname(); | |
242 | if (!v9ses->uname) | |
243 | return ERR_PTR(-ENOMEM); | |
244 | ||
245 | v9ses->aname = __getname(); | |
246 | if (!v9ses->aname) { | |
247 | __putname(v9ses->uname); | |
248 | return ERR_PTR(-ENOMEM); | |
249 | } | |
250 | init_rwsem(&v9ses->rename_sem); | |
251 | ||
252 | rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY); | |
253 | if (rc) { | |
254 | __putname(v9ses->aname); | |
255 | __putname(v9ses->uname); | |
256 | return ERR_PTR(rc); | |
257 | } | |
258 | ||
259 | spin_lock(&v9fs_sessionlist_lock); | |
260 | list_add(&v9ses->slist, &v9fs_sessionlist); | |
261 | spin_unlock(&v9fs_sessionlist_lock); | |
262 | ||
263 | v9ses->flags = V9FS_ACCESS_USER; | |
264 | strcpy(v9ses->uname, V9FS_DEFUSER); | |
265 | strcpy(v9ses->aname, V9FS_DEFANAME); | |
266 | v9ses->uid = ~0; | |
267 | v9ses->dfltuid = V9FS_DEFUID; | |
268 | v9ses->dfltgid = V9FS_DEFGID; | |
269 | ||
270 | rc = v9fs_parse_options(v9ses, data); | |
271 | if (rc < 0) { | |
272 | retval = rc; | |
273 | goto error; | |
274 | } | |
275 | ||
276 | v9ses->clnt = p9_client_create(dev_name, data); | |
277 | if (IS_ERR(v9ses->clnt)) { | |
278 | retval = PTR_ERR(v9ses->clnt); | |
279 | v9ses->clnt = NULL; | |
280 | P9_DPRINTK(P9_DEBUG_ERROR, "problem initializing 9p client\n"); | |
281 | goto error; | |
282 | } | |
283 | ||
284 | if (p9_is_proto_dotl(v9ses->clnt)) | |
285 | v9ses->flags |= V9FS_PROTO_2000L; | |
286 | else if (p9_is_proto_dotu(v9ses->clnt)) | |
287 | v9ses->flags |= V9FS_PROTO_2000U; | |
288 | ||
289 | v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ; | |
290 | ||
291 | if (!v9fs_proto_dotl(v9ses) && | |
292 | ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) { | |
293 | /* | |
294 | * We support ACCESS_CLIENT only for dotl. | |
295 | * Fall back to ACCESS_USER | |
296 | */ | |
297 | v9ses->flags &= ~V9FS_ACCESS_MASK; | |
298 | v9ses->flags |= V9FS_ACCESS_USER; | |
299 | } | |
300 | /*FIXME !! */ | |
301 | /* for legacy mode, fall back to V9FS_ACCESS_ANY */ | |
302 | if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) && | |
303 | ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) { | |
304 | ||
305 | v9ses->flags &= ~V9FS_ACCESS_MASK; | |
306 | v9ses->flags |= V9FS_ACCESS_ANY; | |
307 | v9ses->uid = ~0; | |
308 | } | |
309 | ||
310 | fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, ~0, | |
311 | v9ses->aname); | |
312 | if (IS_ERR(fid)) { | |
313 | retval = PTR_ERR(fid); | |
314 | fid = NULL; | |
315 | P9_DPRINTK(P9_DEBUG_ERROR, "cannot attach\n"); | |
316 | goto error; | |
317 | } | |
318 | ||
319 | if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE) | |
320 | fid->uid = v9ses->uid; | |
321 | else | |
322 | fid->uid = ~0; | |
323 | ||
324 | #ifdef CONFIG_9P_FSCACHE | |
325 | /* register the session for caching */ | |
326 | v9fs_cache_session_get_cookie(v9ses); | |
327 | #endif | |
328 | ||
329 | return fid; | |
330 | ||
331 | error: | |
332 | bdi_destroy(&v9ses->bdi); | |
333 | return ERR_PTR(retval); | |
334 | } | |
335 | ||
336 | /** | |
337 | * v9fs_session_close - shutdown a session | |
338 | * @v9ses: session information structure | |
339 | * | |
340 | */ | |
341 | ||
342 | void v9fs_session_close(struct v9fs_session_info *v9ses) | |
343 | { | |
344 | if (v9ses->clnt) { | |
345 | p9_client_destroy(v9ses->clnt); | |
346 | v9ses->clnt = NULL; | |
347 | } | |
348 | ||
349 | #ifdef CONFIG_9P_FSCACHE | |
350 | if (v9ses->fscache) { | |
351 | v9fs_cache_session_put_cookie(v9ses); | |
352 | kfree(v9ses->cachetag); | |
353 | } | |
354 | #endif | |
355 | __putname(v9ses->uname); | |
356 | __putname(v9ses->aname); | |
357 | ||
358 | bdi_destroy(&v9ses->bdi); | |
359 | ||
360 | spin_lock(&v9fs_sessionlist_lock); | |
361 | list_del(&v9ses->slist); | |
362 | spin_unlock(&v9fs_sessionlist_lock); | |
363 | } | |
364 | ||
365 | /** | |
366 | * v9fs_session_cancel - terminate a session | |
367 | * @v9ses: session to terminate | |
368 | * | |
369 | * mark transport as disconnected and cancel all pending requests. | |
370 | */ | |
371 | ||
372 | void v9fs_session_cancel(struct v9fs_session_info *v9ses) { | |
373 | P9_DPRINTK(P9_DEBUG_ERROR, "cancel session %p\n", v9ses); | |
374 | p9_client_disconnect(v9ses->clnt); | |
375 | } | |
376 | ||
377 | /** | |
378 | * v9fs_session_begin_cancel - Begin terminate of a session | |
379 | * @v9ses: session to terminate | |
380 | * | |
381 | * After this call we don't allow any request other than clunk. | |
382 | */ | |
383 | ||
384 | void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses) | |
385 | { | |
386 | P9_DPRINTK(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses); | |
387 | p9_client_begin_disconnect(v9ses->clnt); | |
388 | } | |
389 | ||
390 | extern int v9fs_error_init(void); | |
391 | ||
392 | static struct kobject *v9fs_kobj; | |
393 | ||
394 | #ifdef CONFIG_9P_FSCACHE | |
395 | /** | |
396 | * caches_show - list caches associated with a session | |
397 | * | |
398 | * Returns the size of buffer written. | |
399 | */ | |
400 | ||
401 | static ssize_t caches_show(struct kobject *kobj, | |
402 | struct kobj_attribute *attr, | |
403 | char *buf) | |
404 | { | |
405 | ssize_t n = 0, count = 0, limit = PAGE_SIZE; | |
406 | struct v9fs_session_info *v9ses; | |
407 | ||
408 | spin_lock(&v9fs_sessionlist_lock); | |
409 | list_for_each_entry(v9ses, &v9fs_sessionlist, slist) { | |
410 | if (v9ses->cachetag) { | |
411 | n = snprintf(buf, limit, "%s\n", v9ses->cachetag); | |
412 | if (n < 0) { | |
413 | count = n; | |
414 | break; | |
415 | } | |
416 | ||
417 | count += n; | |
418 | limit -= n; | |
419 | } | |
420 | } | |
421 | ||
422 | spin_unlock(&v9fs_sessionlist_lock); | |
423 | return count; | |
424 | } | |
425 | ||
426 | static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches); | |
427 | #endif /* CONFIG_9P_FSCACHE */ | |
428 | ||
429 | static struct attribute *v9fs_attrs[] = { | |
430 | #ifdef CONFIG_9P_FSCACHE | |
431 | &v9fs_attr_cache.attr, | |
432 | #endif | |
433 | NULL, | |
434 | }; | |
435 | ||
436 | static struct attribute_group v9fs_attr_group = { | |
437 | .attrs = v9fs_attrs, | |
438 | }; | |
439 | ||
440 | /** | |
441 | * v9fs_sysfs_init - Initialize the v9fs sysfs interface | |
442 | * | |
443 | */ | |
444 | ||
445 | static int v9fs_sysfs_init(void) | |
446 | { | |
447 | v9fs_kobj = kobject_create_and_add("9p", fs_kobj); | |
448 | if (!v9fs_kobj) | |
449 | return -ENOMEM; | |
450 | ||
451 | if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) { | |
452 | kobject_put(v9fs_kobj); | |
453 | return -ENOMEM; | |
454 | } | |
455 | ||
456 | return 0; | |
457 | } | |
458 | ||
459 | /** | |
460 | * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface | |
461 | * | |
462 | */ | |
463 | ||
464 | static void v9fs_sysfs_cleanup(void) | |
465 | { | |
466 | sysfs_remove_group(v9fs_kobj, &v9fs_attr_group); | |
467 | kobject_put(v9fs_kobj); | |
468 | } | |
469 | ||
470 | /** | |
471 | * init_v9fs - Initialize module | |
472 | * | |
473 | */ | |
474 | ||
475 | static int __init init_v9fs(void) | |
476 | { | |
477 | int err; | |
478 | printk(KERN_INFO "Installing v9fs 9p2000 file system support\n"); | |
479 | /* TODO: Setup list of registered trasnport modules */ | |
480 | err = register_filesystem(&v9fs_fs_type); | |
481 | if (err < 0) { | |
482 | printk(KERN_ERR "Failed to register filesystem\n"); | |
483 | return err; | |
484 | } | |
485 | ||
486 | err = v9fs_cache_register(); | |
487 | if (err < 0) { | |
488 | printk(KERN_ERR "Failed to register v9fs for caching\n"); | |
489 | goto out_fs_unreg; | |
490 | } | |
491 | ||
492 | err = v9fs_sysfs_init(); | |
493 | if (err < 0) { | |
494 | printk(KERN_ERR "Failed to register with sysfs\n"); | |
495 | goto out_sysfs_cleanup; | |
496 | } | |
497 | ||
498 | return 0; | |
499 | ||
500 | out_sysfs_cleanup: | |
501 | v9fs_sysfs_cleanup(); | |
502 | ||
503 | out_fs_unreg: | |
504 | unregister_filesystem(&v9fs_fs_type); | |
505 | ||
506 | return err; | |
507 | } | |
508 | ||
509 | /** | |
510 | * exit_v9fs - shutdown module | |
511 | * | |
512 | */ | |
513 | ||
514 | static void __exit exit_v9fs(void) | |
515 | { | |
516 | v9fs_sysfs_cleanup(); | |
517 | v9fs_cache_unregister(); | |
518 | unregister_filesystem(&v9fs_fs_type); | |
519 | } | |
520 | ||
521 | module_init(init_v9fs) | |
522 | module_exit(exit_v9fs) | |
523 | ||
524 | MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>"); | |
525 | MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>"); | |
526 | MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>"); | |
527 | MODULE_LICENSE("GPL"); |