xref: /openbmc/linux/fs/9p/v9fs.c (revision e0f6d1a5) 
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
27 
28 #include <linux/module.h>
29 #include <linux/errno.h>
30 #include <linux/fs.h>
31 #include <linux/sched.h>
32 #include <linux/cred.h>
33 #include <linux/parser.h>
34 #include <linux/idr.h>
35 #include <linux/slab.h>
36 #include <linux/seq_file.h>
37 #include <net/9p/9p.h>
38 #include <net/9p/client.h>
39 #include <net/9p/transport.h>
40 #include "v9fs.h"
41 #include "v9fs_vfs.h"
42 #include "cache.h"
43 
44 static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
45 static LIST_HEAD(v9fs_sessionlist);
46 struct kmem_cache *v9fs_inode_cache;
47 
48 /*
49  * Option Parsing (code inspired by NFS code)
50  *  NOTE: each transport will parse its own options
51  */
52 
53 enum {
54 	/* Options that take integer arguments */
55 	Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
56 	/* String options */
57 	Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
58 	/* Options that take no arguments */
59 	Opt_nodevmap,
60 	/* Cache options */
61 	Opt_cache_loose, Opt_fscache, Opt_mmap,
62 	/* Access options */
63 	Opt_access, Opt_posixacl,
64 	/* Error token */
65 	Opt_err
66 };
67 
68 static const match_table_t tokens = {
69 	{Opt_debug, "debug=%x"},
70 	{Opt_dfltuid, "dfltuid=%u"},
71 	{Opt_dfltgid, "dfltgid=%u"},
72 	{Opt_afid, "afid=%u"},
73 	{Opt_uname, "uname=%s"},
74 	{Opt_remotename, "aname=%s"},
75 	{Opt_nodevmap, "nodevmap"},
76 	{Opt_cache, "cache=%s"},
77 	{Opt_cache_loose, "loose"},
78 	{Opt_fscache, "fscache"},
79 	{Opt_mmap, "mmap"},
80 	{Opt_cachetag, "cachetag=%s"},
81 	{Opt_access, "access=%s"},
82 	{Opt_posixacl, "posixacl"},
83 	{Opt_err, NULL}
84 };
85 
86 static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
87 	[CACHE_NONE]	= "none",
88 	[CACHE_MMAP]	= "mmap",
89 	[CACHE_LOOSE]	= "loose",
90 	[CACHE_FSCACHE]	= "fscache",
91 };
92 
93 /* Interpret mount options for cache mode */
94 static int get_cache_mode(char *s)
95 {
96 	int version = -EINVAL;
97 
98 	if (!strcmp(s, "loose")) {
99 		version = CACHE_LOOSE;
100 		p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
101 	} else if (!strcmp(s, "fscache")) {
102 		version = CACHE_FSCACHE;
103 		p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
104 	} else if (!strcmp(s, "mmap")) {
105 		version = CACHE_MMAP;
106 		p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
107 	} else if (!strcmp(s, "none")) {
108 		version = CACHE_NONE;
109 		p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
110 	} else
111 		pr_info("Unknown Cache mode %s\n", s);
112 	return version;
113 }
114 
115 /*
116  * Display the mount options in /proc/mounts.
117  */
118 int v9fs_show_options(struct seq_file *m, struct dentry *root)
119 {
120 	struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
121 
122 	if (v9ses->debug)
123 		seq_printf(m, ",debug=%x", v9ses->debug);
124 	if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
125 		seq_printf(m, ",dfltuid=%u",
126 			   from_kuid_munged(&init_user_ns, v9ses->dfltuid));
127 	if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
128 		seq_printf(m, ",dfltgid=%u",
129 			   from_kgid_munged(&init_user_ns, v9ses->dfltgid));
130 	if (v9ses->afid != ~0)
131 		seq_printf(m, ",afid=%u", v9ses->afid);
132 	if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
133 		seq_printf(m, ",uname=%s", v9ses->uname);
134 	if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
135 		seq_printf(m, ",aname=%s", v9ses->aname);
136 	if (v9ses->nodev)
137 		seq_puts(m, ",nodevmap");
138 	if (v9ses->cache)
139 		seq_printf(m, ",%s", v9fs_cache_modes[v9ses->cache]);
140 #ifdef CONFIG_9P_FSCACHE
141 	if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
142 		seq_printf(m, ",cachetag=%s", v9ses->cachetag);
143 #endif
144 
145 	switch (v9ses->flags & V9FS_ACCESS_MASK) {
146 	case V9FS_ACCESS_USER:
147 		seq_puts(m, ",access=user");
148 		break;
149 	case V9FS_ACCESS_ANY:
150 		seq_puts(m, ",access=any");
151 		break;
152 	case V9FS_ACCESS_CLIENT:
153 		seq_puts(m, ",access=client");
154 		break;
155 	case V9FS_ACCESS_SINGLE:
156 		seq_printf(m, ",access=%u",
157 			   from_kuid_munged(&init_user_ns, v9ses->uid));
158 		break;
159 	}
160 
161 	if (v9ses->flags & V9FS_POSIX_ACL)
162 		seq_puts(m, ",posixacl");
163 
164 	return p9_show_client_options(m, v9ses->clnt);
165 }
166 
167 /**
168  * v9fs_parse_options - parse mount options into session structure
169  * @v9ses: existing v9fs session information
170  *
171  * Return 0 upon success, -ERRNO upon failure.
172  */
173 
174 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
175 {
176 	char *options, *tmp_options;
177 	substring_t args[MAX_OPT_ARGS];
178 	char *p;
179 	int option = 0;
180 	char *s, *e;
181 	int ret = 0;
182 
183 	/* setup defaults */
184 	v9ses->afid = ~0;
185 	v9ses->debug = 0;
186 	v9ses->cache = CACHE_NONE;
187 #ifdef CONFIG_9P_FSCACHE
188 	v9ses->cachetag = NULL;
189 #endif
190 
191 	if (!opts)
192 		return 0;
193 
194 	tmp_options = kstrdup(opts, GFP_KERNEL);
195 	if (!tmp_options) {
196 		ret = -ENOMEM;
197 		goto fail_option_alloc;
198 	}
199 	options = tmp_options;
200 
201 	while ((p = strsep(&options, ",")) != NULL) {
202 		int token, r;
203 		if (!*p)
204 			continue;
205 		token = match_token(p, tokens, args);
206 		switch (token) {
207 		case Opt_debug:
208 			r = match_int(&args[0], &option);
209 			if (r < 0) {
210 				p9_debug(P9_DEBUG_ERROR,
211 					 "integer field, but no integer?\n");
212 				ret = r;
213 				continue;
214 			}
215 			v9ses->debug = option;
216 #ifdef CONFIG_NET_9P_DEBUG
217 			p9_debug_level = option;
218 #endif
219 			break;
220 
221 		case Opt_dfltuid:
222 			r = match_int(&args[0], &option);
223 			if (r < 0) {
224 				p9_debug(P9_DEBUG_ERROR,
225 					 "integer field, but no integer?\n");
226 				ret = r;
227 				continue;
228 			}
229 			v9ses->dfltuid = make_kuid(current_user_ns(), option);
230 			if (!uid_valid(v9ses->dfltuid)) {
231 				p9_debug(P9_DEBUG_ERROR,
232 					 "uid field, but not a uid?\n");
233 				ret = -EINVAL;
234 				continue;
235 			}
236 			break;
237 		case Opt_dfltgid:
238 			r = match_int(&args[0], &option);
239 			if (r < 0) {
240 				p9_debug(P9_DEBUG_ERROR,
241 					 "integer field, but no integer?\n");
242 				ret = r;
243 				continue;
244 			}
245 			v9ses->dfltgid = make_kgid(current_user_ns(), option);
246 			if (!gid_valid(v9ses->dfltgid)) {
247 				p9_debug(P9_DEBUG_ERROR,
248 					 "gid field, but not a gid?\n");
249 				ret = -EINVAL;
250 				continue;
251 			}
252 			break;
253 		case Opt_afid:
254 			r = match_int(&args[0], &option);
255 			if (r < 0) {
256 				p9_debug(P9_DEBUG_ERROR,
257 					 "integer field, but no integer?\n");
258 				ret = r;
259 				continue;
260 			}
261 			v9ses->afid = option;
262 			break;
263 		case Opt_uname:
264 			kfree(v9ses->uname);
265 			v9ses->uname = match_strdup(&args[0]);
266 			if (!v9ses->uname) {
267 				ret = -ENOMEM;
268 				goto free_and_return;
269 			}
270 			break;
271 		case Opt_remotename:
272 			kfree(v9ses->aname);
273 			v9ses->aname = match_strdup(&args[0]);
274 			if (!v9ses->aname) {
275 				ret = -ENOMEM;
276 				goto free_and_return;
277 			}
278 			break;
279 		case Opt_nodevmap:
280 			v9ses->nodev = 1;
281 			break;
282 		case Opt_cache_loose:
283 			v9ses->cache = CACHE_LOOSE;
284 			break;
285 		case Opt_fscache:
286 			v9ses->cache = CACHE_FSCACHE;
287 			break;
288 		case Opt_mmap:
289 			v9ses->cache = CACHE_MMAP;
290 			break;
291 		case Opt_cachetag:
292 #ifdef CONFIG_9P_FSCACHE
293 			kfree(v9ses->cachetag);
294 			v9ses->cachetag = match_strdup(&args[0]);
295 			if (!v9ses->cachetag) {
296 				ret = -ENOMEM;
297 				goto free_and_return;
298 			}
299 #endif
300 			break;
301 		case Opt_cache:
302 			s = match_strdup(&args[0]);
303 			if (!s) {
304 				ret = -ENOMEM;
305 				p9_debug(P9_DEBUG_ERROR,
306 					 "problem allocating copy of cache arg\n");
307 				goto free_and_return;
308 			}
309 			ret = get_cache_mode(s);
310 			if (ret == -EINVAL) {
311 				kfree(s);
312 				goto free_and_return;
313 			}
314 
315 			v9ses->cache = ret;
316 			kfree(s);
317 			break;
318 
319 		case Opt_access:
320 			s = match_strdup(&args[0]);
321 			if (!s) {
322 				ret = -ENOMEM;
323 				p9_debug(P9_DEBUG_ERROR,
324 					 "problem allocating copy of access arg\n");
325 				goto free_and_return;
326 			}
327 
328 			v9ses->flags &= ~V9FS_ACCESS_MASK;
329 			if (strcmp(s, "user") == 0)
330 				v9ses->flags |= V9FS_ACCESS_USER;
331 			else if (strcmp(s, "any") == 0)
332 				v9ses->flags |= V9FS_ACCESS_ANY;
333 			else if (strcmp(s, "client") == 0) {
334 				v9ses->flags |= V9FS_ACCESS_CLIENT;
335 			} else {
336 				uid_t uid;
337 				v9ses->flags |= V9FS_ACCESS_SINGLE;
338 				uid = simple_strtoul(s, &e, 10);
339 				if (*e != '\0') {
340 					ret = -EINVAL;
341 					pr_info("Unknown access argument %s\n",
342 						s);
343 					kfree(s);
344 					goto free_and_return;
345 				}
346 				v9ses->uid = make_kuid(current_user_ns(), uid);
347 				if (!uid_valid(v9ses->uid)) {
348 					ret = -EINVAL;
349 					pr_info("Uknown uid %s\n", s);
350 					kfree(s);
351 					goto free_and_return;
352 				}
353 			}
354 
355 			kfree(s);
356 			break;
357 
358 		case Opt_posixacl:
359 #ifdef CONFIG_9P_FS_POSIX_ACL
360 			v9ses->flags |= V9FS_POSIX_ACL;
361 #else
362 			p9_debug(P9_DEBUG_ERROR,
363 				 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
364 #endif
365 			break;
366 
367 		default:
368 			continue;
369 		}
370 	}
371 
372 free_and_return:
373 	kfree(tmp_options);
374 fail_option_alloc:
375 	return ret;
376 }
377 
378 /**
379  * v9fs_session_init - initialize session
380  * @v9ses: session information structure
381  * @dev_name: device being mounted
382  * @data: options
383  *
384  */
385 
386 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
387 		  const char *dev_name, char *data)
388 {
389 	struct p9_fid *fid;
390 	int rc = -ENOMEM;
391 
392 	v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
393 	if (!v9ses->uname)
394 		goto err_names;
395 
396 	v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
397 	if (!v9ses->aname)
398 		goto err_names;
399 	init_rwsem(&v9ses->rename_sem);
400 
401 	v9ses->uid = INVALID_UID;
402 	v9ses->dfltuid = V9FS_DEFUID;
403 	v9ses->dfltgid = V9FS_DEFGID;
404 
405 	v9ses->clnt = p9_client_create(dev_name, data);
406 	if (IS_ERR(v9ses->clnt)) {
407 		rc = PTR_ERR(v9ses->clnt);
408 		p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
409 		goto err_names;
410 	}
411 
412 	v9ses->flags = V9FS_ACCESS_USER;
413 
414 	if (p9_is_proto_dotl(v9ses->clnt)) {
415 		v9ses->flags = V9FS_ACCESS_CLIENT;
416 		v9ses->flags |= V9FS_PROTO_2000L;
417 	} else if (p9_is_proto_dotu(v9ses->clnt)) {
418 		v9ses->flags |= V9FS_PROTO_2000U;
419 	}
420 
421 	rc = v9fs_parse_options(v9ses, data);
422 	if (rc < 0)
423 		goto err_clnt;
424 
425 	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
426 
427 	if (!v9fs_proto_dotl(v9ses) &&
428 	    ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
429 		/*
430 		 * We support ACCESS_CLIENT only for dotl.
431 		 * Fall back to ACCESS_USER
432 		 */
433 		v9ses->flags &= ~V9FS_ACCESS_MASK;
434 		v9ses->flags |= V9FS_ACCESS_USER;
435 	}
436 	/*FIXME !! */
437 	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
438 	if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
439 		((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
440 
441 		v9ses->flags &= ~V9FS_ACCESS_MASK;
442 		v9ses->flags |= V9FS_ACCESS_ANY;
443 		v9ses->uid = INVALID_UID;
444 	}
445 	if (!v9fs_proto_dotl(v9ses) ||
446 		!((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
447 		/*
448 		 * We support ACL checks on clinet only if the protocol is
449 		 * 9P2000.L and access is V9FS_ACCESS_CLIENT.
450 		 */
451 		v9ses->flags &= ~V9FS_ACL_MASK;
452 	}
453 
454 	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
455 							v9ses->aname);
456 	if (IS_ERR(fid)) {
457 		rc = PTR_ERR(fid);
458 		p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
459 		goto err_clnt;
460 	}
461 
462 	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
463 		fid->uid = v9ses->uid;
464 	else
465 		fid->uid = INVALID_UID;
466 
467 #ifdef CONFIG_9P_FSCACHE
468 	/* register the session for caching */
469 	v9fs_cache_session_get_cookie(v9ses);
470 #endif
471 	spin_lock(&v9fs_sessionlist_lock);
472 	list_add(&v9ses->slist, &v9fs_sessionlist);
473 	spin_unlock(&v9fs_sessionlist_lock);
474 
475 	return fid;
476 
477 err_clnt:
478 #ifdef CONFIG_9P_FSCACHE
479 	kfree(v9ses->cachetag);
480 #endif
481 	p9_client_destroy(v9ses->clnt);
482 err_names:
483 	kfree(v9ses->uname);
484 	kfree(v9ses->aname);
485 	return ERR_PTR(rc);
486 }
487 
488 /**
489  * v9fs_session_close - shutdown a session
490  * @v9ses: session information structure
491  *
492  */
493 
494 void v9fs_session_close(struct v9fs_session_info *v9ses)
495 {
496 	if (v9ses->clnt) {
497 		p9_client_destroy(v9ses->clnt);
498 		v9ses->clnt = NULL;
499 	}
500 
501 #ifdef CONFIG_9P_FSCACHE
502 	if (v9ses->fscache) {
503 		v9fs_cache_session_put_cookie(v9ses);
504 		kfree(v9ses->cachetag);
505 	}
506 #endif
507 	kfree(v9ses->uname);
508 	kfree(v9ses->aname);
509 
510 	spin_lock(&v9fs_sessionlist_lock);
511 	list_del(&v9ses->slist);
512 	spin_unlock(&v9fs_sessionlist_lock);
513 }
514 
515 /**
516  * v9fs_session_cancel - terminate a session
517  * @v9ses: session to terminate
518  *
519  * mark transport as disconnected and cancel all pending requests.
520  */
521 
522 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
523 	p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
524 	p9_client_disconnect(v9ses->clnt);
525 }
526 
527 /**
528  * v9fs_session_begin_cancel - Begin terminate of a session
529  * @v9ses: session to terminate
530  *
531  * After this call we don't allow any request other than clunk.
532  */
533 
534 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
535 {
536 	p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
537 	p9_client_begin_disconnect(v9ses->clnt);
538 }
539 
540 extern int v9fs_error_init(void);
541 
542 static struct kobject *v9fs_kobj;
543 
544 #ifdef CONFIG_9P_FSCACHE
545 /**
546  * caches_show - list caches associated with a session
547  *
548  * Returns the size of buffer written.
549  */
550 
551 static ssize_t caches_show(struct kobject *kobj,
552 			   struct kobj_attribute *attr,
553 			   char *buf)
554 {
555 	ssize_t n = 0, count = 0, limit = PAGE_SIZE;
556 	struct v9fs_session_info *v9ses;
557 
558 	spin_lock(&v9fs_sessionlist_lock);
559 	list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
560 		if (v9ses->cachetag) {
561 			n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
562 			if (n < 0) {
563 				count = n;
564 				break;
565 			}
566 
567 			count += n;
568 			limit -= n;
569 		}
570 	}
571 
572 	spin_unlock(&v9fs_sessionlist_lock);
573 	return count;
574 }
575 
576 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
577 #endif /* CONFIG_9P_FSCACHE */
578 
579 static struct attribute *v9fs_attrs[] = {
580 #ifdef CONFIG_9P_FSCACHE
581 	&v9fs_attr_cache.attr,
582 #endif
583 	NULL,
584 };
585 
586 static struct attribute_group v9fs_attr_group = {
587 	.attrs = v9fs_attrs,
588 };
589 
590 /**
591  * v9fs_sysfs_init - Initialize the v9fs sysfs interface
592  *
593  */
594 
595 static int __init v9fs_sysfs_init(void)
596 {
597 	v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
598 	if (!v9fs_kobj)
599 		return -ENOMEM;
600 
601 	if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
602 		kobject_put(v9fs_kobj);
603 		return -ENOMEM;
604 	}
605 
606 	return 0;
607 }
608 
609 /**
610  * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
611  *
612  */
613 
614 static void v9fs_sysfs_cleanup(void)
615 {
616 	sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
617 	kobject_put(v9fs_kobj);
618 }
619 
620 static void v9fs_inode_init_once(void *foo)
621 {
622 	struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
623 #ifdef CONFIG_9P_FSCACHE
624 	v9inode->fscache = NULL;
625 #endif
626 	memset(&v9inode->qid, 0, sizeof(v9inode->qid));
627 	inode_init_once(&v9inode->vfs_inode);
628 }
629 
630 /**
631  * v9fs_init_inode_cache - initialize a cache for 9P
632  * Returns 0 on success.
633  */
634 static int v9fs_init_inode_cache(void)
635 {
636 	v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
637 					  sizeof(struct v9fs_inode),
638 					  0, (SLAB_RECLAIM_ACCOUNT|
639 					      SLAB_MEM_SPREAD|SLAB_ACCOUNT),
640 					  v9fs_inode_init_once);
641 	if (!v9fs_inode_cache)
642 		return -ENOMEM;
643 
644 	return 0;
645 }
646 
647 /**
648  * v9fs_destroy_inode_cache - destroy the cache of 9P inode
649  *
650  */
651 static void v9fs_destroy_inode_cache(void)
652 {
653 	/*
654 	 * Make sure all delayed rcu free inodes are flushed before we
655 	 * destroy cache.
656 	 */
657 	rcu_barrier();
658 	kmem_cache_destroy(v9fs_inode_cache);
659 }
660 
661 static int v9fs_cache_register(void)
662 {
663 	int ret;
664 	ret = v9fs_init_inode_cache();
665 	if (ret < 0)
666 		return ret;
667 #ifdef CONFIG_9P_FSCACHE
668 	ret = fscache_register_netfs(&v9fs_cache_netfs);
669 	if (ret < 0)
670 		v9fs_destroy_inode_cache();
671 #endif
672 	return ret;
673 }
674 
675 static void v9fs_cache_unregister(void)
676 {
677 	v9fs_destroy_inode_cache();
678 #ifdef CONFIG_9P_FSCACHE
679 	fscache_unregister_netfs(&v9fs_cache_netfs);
680 #endif
681 }
682 
683 /**
684  * init_v9fs - Initialize module
685  *
686  */
687 
688 static int __init init_v9fs(void)
689 {
690 	int err;
691 	pr_info("Installing v9fs 9p2000 file system support\n");
692 	/* TODO: Setup list of registered trasnport modules */
693 
694 	err = v9fs_cache_register();
695 	if (err < 0) {
696 		pr_err("Failed to register v9fs for caching\n");
697 		return err;
698 	}
699 
700 	err = v9fs_sysfs_init();
701 	if (err < 0) {
702 		pr_err("Failed to register with sysfs\n");
703 		goto out_cache;
704 	}
705 	err = register_filesystem(&v9fs_fs_type);
706 	if (err < 0) {
707 		pr_err("Failed to register filesystem\n");
708 		goto out_sysfs_cleanup;
709 	}
710 
711 	return 0;
712 
713 out_sysfs_cleanup:
714 	v9fs_sysfs_cleanup();
715 
716 out_cache:
717 	v9fs_cache_unregister();
718 
719 	return err;
720 }
721 
722 /**
723  * exit_v9fs - shutdown module
724  *
725  */
726 
727 static void __exit exit_v9fs(void)
728 {
729 	v9fs_sysfs_cleanup();
730 	v9fs_cache_unregister();
731 	unregister_filesystem(&v9fs_fs_type);
732 }
733 
734 module_init(init_v9fs)
735 module_exit(exit_v9fs)
736 
737 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
738 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
739 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
740 MODULE_LICENSE("GPL");
741