xref: /openbmc/linux/fs/9p/v9fs.c (revision de6e9190) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/fs/9p/v9fs.c
4  *
5  *  This file contains functions assisting in mapping VFS to 9P2000
6  *
7  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
8  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
9  */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/module.h>
14 #include <linux/errno.h>
15 #include <linux/fs.h>
16 #include <linux/sched.h>
17 #include <linux/cred.h>
18 #include <linux/parser.h>
19 #include <linux/idr.h>
20 #include <linux/slab.h>
21 #include <linux/seq_file.h>
22 #include <net/9p/9p.h>
23 #include <net/9p/client.h>
24 #include <net/9p/transport.h>
25 #include "v9fs.h"
26 #include "v9fs_vfs.h"
27 #include "cache.h"
28 
29 static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
30 static LIST_HEAD(v9fs_sessionlist);
31 struct kmem_cache *v9fs_inode_cache;
32 
33 /*
34  * Option Parsing (code inspired by NFS code)
35  *  NOTE: each transport will parse its own options
36  */
37 
38 enum {
39 	/* Options that take integer arguments */
40 	Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
41 	/* String options */
42 	Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
43 	/* Options that take no arguments */
44 	Opt_nodevmap,
45 	/* Cache options */
46 	Opt_cache_loose, Opt_fscache, Opt_mmap,
47 	/* Access options */
48 	Opt_access, Opt_posixacl,
49 	/* Lock timeout option */
50 	Opt_locktimeout,
51 	/* Error token */
52 	Opt_err
53 };
54 
55 static const match_table_t tokens = {
56 	{Opt_debug, "debug=%x"},
57 	{Opt_dfltuid, "dfltuid=%u"},
58 	{Opt_dfltgid, "dfltgid=%u"},
59 	{Opt_afid, "afid=%u"},
60 	{Opt_uname, "uname=%s"},
61 	{Opt_remotename, "aname=%s"},
62 	{Opt_nodevmap, "nodevmap"},
63 	{Opt_cache, "cache=%s"},
64 	{Opt_cache_loose, "loose"},
65 	{Opt_fscache, "fscache"},
66 	{Opt_mmap, "mmap"},
67 	{Opt_cachetag, "cachetag=%s"},
68 	{Opt_access, "access=%s"},
69 	{Opt_posixacl, "posixacl"},
70 	{Opt_locktimeout, "locktimeout=%u"},
71 	{Opt_err, NULL}
72 };
73 
74 static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
75 	[CACHE_NONE]	= "none",
76 	[CACHE_MMAP]	= "mmap",
77 	[CACHE_LOOSE]	= "loose",
78 	[CACHE_FSCACHE]	= "fscache",
79 };
80 
81 /* Interpret mount options for cache mode */
82 static int get_cache_mode(char *s)
83 {
84 	int version = -EINVAL;
85 
86 	if (!strcmp(s, "loose")) {
87 		version = CACHE_LOOSE;
88 		p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
89 	} else if (!strcmp(s, "fscache")) {
90 		version = CACHE_FSCACHE;
91 		p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
92 	} else if (!strcmp(s, "mmap")) {
93 		version = CACHE_MMAP;
94 		p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
95 	} else if (!strcmp(s, "none")) {
96 		version = CACHE_NONE;
97 		p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
98 	} else
99 		pr_info("Unknown Cache mode %s\n", s);
100 	return version;
101 }
102 
103 /*
104  * Display the mount options in /proc/mounts.
105  */
106 int v9fs_show_options(struct seq_file *m, struct dentry *root)
107 {
108 	struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
109 
110 	if (v9ses->debug)
111 		seq_printf(m, ",debug=%x", v9ses->debug);
112 	if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
113 		seq_printf(m, ",dfltuid=%u",
114 			   from_kuid_munged(&init_user_ns, v9ses->dfltuid));
115 	if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
116 		seq_printf(m, ",dfltgid=%u",
117 			   from_kgid_munged(&init_user_ns, v9ses->dfltgid));
118 	if (v9ses->afid != ~0)
119 		seq_printf(m, ",afid=%u", v9ses->afid);
120 	if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
121 		seq_printf(m, ",uname=%s", v9ses->uname);
122 	if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
123 		seq_printf(m, ",aname=%s", v9ses->aname);
124 	if (v9ses->nodev)
125 		seq_puts(m, ",nodevmap");
126 	if (v9ses->cache)
127 		seq_printf(m, ",%s", v9fs_cache_modes[v9ses->cache]);
128 #ifdef CONFIG_9P_FSCACHE
129 	if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
130 		seq_printf(m, ",cachetag=%s", v9ses->cachetag);
131 #endif
132 
133 	switch (v9ses->flags & V9FS_ACCESS_MASK) {
134 	case V9FS_ACCESS_USER:
135 		seq_puts(m, ",access=user");
136 		break;
137 	case V9FS_ACCESS_ANY:
138 		seq_puts(m, ",access=any");
139 		break;
140 	case V9FS_ACCESS_CLIENT:
141 		seq_puts(m, ",access=client");
142 		break;
143 	case V9FS_ACCESS_SINGLE:
144 		seq_printf(m, ",access=%u",
145 			   from_kuid_munged(&init_user_ns, v9ses->uid));
146 		break;
147 	}
148 
149 	if (v9ses->flags & V9FS_POSIX_ACL)
150 		seq_puts(m, ",posixacl");
151 
152 	return p9_show_client_options(m, v9ses->clnt);
153 }
154 
155 /**
156  * v9fs_parse_options - parse mount options into session structure
157  * @v9ses: existing v9fs session information
158  * @opts: The mount option string
159  *
160  * Return 0 upon success, -ERRNO upon failure.
161  */
162 
163 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
164 {
165 	char *options, *tmp_options;
166 	substring_t args[MAX_OPT_ARGS];
167 	char *p;
168 	int option = 0;
169 	char *s, *e;
170 	int ret = 0;
171 
172 	/* setup defaults */
173 	v9ses->afid = ~0;
174 	v9ses->debug = 0;
175 	v9ses->cache = CACHE_NONE;
176 #ifdef CONFIG_9P_FSCACHE
177 	v9ses->cachetag = NULL;
178 #endif
179 	v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
180 
181 	if (!opts)
182 		return 0;
183 
184 	tmp_options = kstrdup(opts, GFP_KERNEL);
185 	if (!tmp_options) {
186 		ret = -ENOMEM;
187 		goto fail_option_alloc;
188 	}
189 	options = tmp_options;
190 
191 	while ((p = strsep(&options, ",")) != NULL) {
192 		int token, r;
193 		if (!*p)
194 			continue;
195 		token = match_token(p, tokens, args);
196 		switch (token) {
197 		case Opt_debug:
198 			r = match_int(&args[0], &option);
199 			if (r < 0) {
200 				p9_debug(P9_DEBUG_ERROR,
201 					 "integer field, but no integer?\n");
202 				ret = r;
203 			} else {
204 				v9ses->debug = option;
205 #ifdef CONFIG_NET_9P_DEBUG
206 				p9_debug_level = option;
207 #endif
208 			}
209 			break;
210 
211 		case Opt_dfltuid:
212 			r = match_int(&args[0], &option);
213 			if (r < 0) {
214 				p9_debug(P9_DEBUG_ERROR,
215 					 "integer field, but no integer?\n");
216 				ret = r;
217 				continue;
218 			}
219 			v9ses->dfltuid = make_kuid(current_user_ns(), option);
220 			if (!uid_valid(v9ses->dfltuid)) {
221 				p9_debug(P9_DEBUG_ERROR,
222 					 "uid field, but not a uid?\n");
223 				ret = -EINVAL;
224 			}
225 			break;
226 		case Opt_dfltgid:
227 			r = match_int(&args[0], &option);
228 			if (r < 0) {
229 				p9_debug(P9_DEBUG_ERROR,
230 					 "integer field, but no integer?\n");
231 				ret = r;
232 				continue;
233 			}
234 			v9ses->dfltgid = make_kgid(current_user_ns(), option);
235 			if (!gid_valid(v9ses->dfltgid)) {
236 				p9_debug(P9_DEBUG_ERROR,
237 					 "gid field, but not a gid?\n");
238 				ret = -EINVAL;
239 			}
240 			break;
241 		case Opt_afid:
242 			r = match_int(&args[0], &option);
243 			if (r < 0) {
244 				p9_debug(P9_DEBUG_ERROR,
245 					 "integer field, but no integer?\n");
246 				ret = r;
247 			} else {
248 				v9ses->afid = option;
249 			}
250 			break;
251 		case Opt_uname:
252 			kfree(v9ses->uname);
253 			v9ses->uname = match_strdup(&args[0]);
254 			if (!v9ses->uname) {
255 				ret = -ENOMEM;
256 				goto free_and_return;
257 			}
258 			break;
259 		case Opt_remotename:
260 			kfree(v9ses->aname);
261 			v9ses->aname = match_strdup(&args[0]);
262 			if (!v9ses->aname) {
263 				ret = -ENOMEM;
264 				goto free_and_return;
265 			}
266 			break;
267 		case Opt_nodevmap:
268 			v9ses->nodev = 1;
269 			break;
270 		case Opt_cache_loose:
271 			v9ses->cache = CACHE_LOOSE;
272 			break;
273 		case Opt_fscache:
274 			v9ses->cache = CACHE_FSCACHE;
275 			break;
276 		case Opt_mmap:
277 			v9ses->cache = CACHE_MMAP;
278 			break;
279 		case Opt_cachetag:
280 #ifdef CONFIG_9P_FSCACHE
281 			kfree(v9ses->cachetag);
282 			v9ses->cachetag = match_strdup(&args[0]);
283 			if (!v9ses->cachetag) {
284 				ret = -ENOMEM;
285 				goto free_and_return;
286 			}
287 #endif
288 			break;
289 		case Opt_cache:
290 			s = match_strdup(&args[0]);
291 			if (!s) {
292 				ret = -ENOMEM;
293 				p9_debug(P9_DEBUG_ERROR,
294 					 "problem allocating copy of cache arg\n");
295 				goto free_and_return;
296 			}
297 			r = get_cache_mode(s);
298 			if (r < 0)
299 				ret = r;
300 			else
301 				v9ses->cache = r;
302 
303 			kfree(s);
304 			break;
305 
306 		case Opt_access:
307 			s = match_strdup(&args[0]);
308 			if (!s) {
309 				ret = -ENOMEM;
310 				p9_debug(P9_DEBUG_ERROR,
311 					 "problem allocating copy of access arg\n");
312 				goto free_and_return;
313 			}
314 
315 			v9ses->flags &= ~V9FS_ACCESS_MASK;
316 			if (strcmp(s, "user") == 0)
317 				v9ses->flags |= V9FS_ACCESS_USER;
318 			else if (strcmp(s, "any") == 0)
319 				v9ses->flags |= V9FS_ACCESS_ANY;
320 			else if (strcmp(s, "client") == 0) {
321 				v9ses->flags |= V9FS_ACCESS_CLIENT;
322 			} else {
323 				uid_t uid;
324 				v9ses->flags |= V9FS_ACCESS_SINGLE;
325 				uid = simple_strtoul(s, &e, 10);
326 				if (*e != '\0') {
327 					ret = -EINVAL;
328 					pr_info("Unknown access argument %s\n",
329 						s);
330 					kfree(s);
331 					continue;
332 				}
333 				v9ses->uid = make_kuid(current_user_ns(), uid);
334 				if (!uid_valid(v9ses->uid)) {
335 					ret = -EINVAL;
336 					pr_info("Unknown uid %s\n", s);
337 				}
338 			}
339 
340 			kfree(s);
341 			break;
342 
343 		case Opt_posixacl:
344 #ifdef CONFIG_9P_FS_POSIX_ACL
345 			v9ses->flags |= V9FS_POSIX_ACL;
346 #else
347 			p9_debug(P9_DEBUG_ERROR,
348 				 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
349 #endif
350 			break;
351 
352 		case Opt_locktimeout:
353 			r = match_int(&args[0], &option);
354 			if (r < 0) {
355 				p9_debug(P9_DEBUG_ERROR,
356 					 "integer field, but no integer?\n");
357 				ret = r;
358 				continue;
359 			}
360 			if (option < 1) {
361 				p9_debug(P9_DEBUG_ERROR,
362 					 "locktimeout must be a greater than zero integer.\n");
363 				ret = -EINVAL;
364 				continue;
365 			}
366 			v9ses->session_lock_timeout = (long)option * HZ;
367 			break;
368 
369 		default:
370 			continue;
371 		}
372 	}
373 
374 free_and_return:
375 	kfree(tmp_options);
376 fail_option_alloc:
377 	return ret;
378 }
379 
380 /**
381  * v9fs_session_init - initialize session
382  * @v9ses: session information structure
383  * @dev_name: device being mounted
384  * @data: options
385  *
386  */
387 
388 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
389 		  const char *dev_name, char *data)
390 {
391 	struct p9_fid *fid;
392 	int rc = -ENOMEM;
393 
394 	v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
395 	if (!v9ses->uname)
396 		goto err_names;
397 
398 	v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
399 	if (!v9ses->aname)
400 		goto err_names;
401 	init_rwsem(&v9ses->rename_sem);
402 
403 	v9ses->uid = INVALID_UID;
404 	v9ses->dfltuid = V9FS_DEFUID;
405 	v9ses->dfltgid = V9FS_DEFGID;
406 
407 	v9ses->clnt = p9_client_create(dev_name, data);
408 	if (IS_ERR(v9ses->clnt)) {
409 		rc = PTR_ERR(v9ses->clnt);
410 		p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
411 		goto err_names;
412 	}
413 
414 	v9ses->flags = V9FS_ACCESS_USER;
415 
416 	if (p9_is_proto_dotl(v9ses->clnt)) {
417 		v9ses->flags = V9FS_ACCESS_CLIENT;
418 		v9ses->flags |= V9FS_PROTO_2000L;
419 	} else if (p9_is_proto_dotu(v9ses->clnt)) {
420 		v9ses->flags |= V9FS_PROTO_2000U;
421 	}
422 
423 	rc = v9fs_parse_options(v9ses, data);
424 	if (rc < 0)
425 		goto err_clnt;
426 
427 	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
428 
429 	if (!v9fs_proto_dotl(v9ses) &&
430 	    ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
431 		/*
432 		 * We support ACCESS_CLIENT only for dotl.
433 		 * Fall back to ACCESS_USER
434 		 */
435 		v9ses->flags &= ~V9FS_ACCESS_MASK;
436 		v9ses->flags |= V9FS_ACCESS_USER;
437 	}
438 	/*FIXME !! */
439 	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
440 	if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
441 		((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
442 
443 		v9ses->flags &= ~V9FS_ACCESS_MASK;
444 		v9ses->flags |= V9FS_ACCESS_ANY;
445 		v9ses->uid = INVALID_UID;
446 	}
447 	if (!v9fs_proto_dotl(v9ses) ||
448 		!((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
449 		/*
450 		 * We support ACL checks on clinet only if the protocol is
451 		 * 9P2000.L and access is V9FS_ACCESS_CLIENT.
452 		 */
453 		v9ses->flags &= ~V9FS_ACL_MASK;
454 	}
455 
456 	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
457 							v9ses->aname);
458 	if (IS_ERR(fid)) {
459 		rc = PTR_ERR(fid);
460 		p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
461 		goto err_clnt;
462 	}
463 
464 	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
465 		fid->uid = v9ses->uid;
466 	else
467 		fid->uid = INVALID_UID;
468 
469 #ifdef CONFIG_9P_FSCACHE
470 	/* register the session for caching */
471 	v9fs_cache_session_get_cookie(v9ses);
472 #endif
473 	spin_lock(&v9fs_sessionlist_lock);
474 	list_add(&v9ses->slist, &v9fs_sessionlist);
475 	spin_unlock(&v9fs_sessionlist_lock);
476 
477 	return fid;
478 
479 err_clnt:
480 #ifdef CONFIG_9P_FSCACHE
481 	kfree(v9ses->cachetag);
482 #endif
483 	p9_client_destroy(v9ses->clnt);
484 err_names:
485 	kfree(v9ses->uname);
486 	kfree(v9ses->aname);
487 	return ERR_PTR(rc);
488 }
489 
490 /**
491  * v9fs_session_close - shutdown a session
492  * @v9ses: session information structure
493  *
494  */
495 
496 void v9fs_session_close(struct v9fs_session_info *v9ses)
497 {
498 	if (v9ses->clnt) {
499 		p9_client_destroy(v9ses->clnt);
500 		v9ses->clnt = NULL;
501 	}
502 
503 #ifdef CONFIG_9P_FSCACHE
504 	if (v9ses->fscache)
505 		v9fs_cache_session_put_cookie(v9ses);
506 	kfree(v9ses->cachetag);
507 #endif
508 	kfree(v9ses->uname);
509 	kfree(v9ses->aname);
510 
511 	spin_lock(&v9fs_sessionlist_lock);
512 	list_del(&v9ses->slist);
513 	spin_unlock(&v9fs_sessionlist_lock);
514 }
515 
516 /**
517  * v9fs_session_cancel - terminate a session
518  * @v9ses: session to terminate
519  *
520  * mark transport as disconnected and cancel all pending requests.
521  */
522 
523 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
524 	p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
525 	p9_client_disconnect(v9ses->clnt);
526 }
527 
528 /**
529  * v9fs_session_begin_cancel - Begin terminate of a session
530  * @v9ses: session to terminate
531  *
532  * After this call we don't allow any request other than clunk.
533  */
534 
535 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
536 {
537 	p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
538 	p9_client_begin_disconnect(v9ses->clnt);
539 }
540 
541 extern int v9fs_error_init(void);
542 
543 static struct kobject *v9fs_kobj;
544 
545 #ifdef CONFIG_9P_FSCACHE
546 /*
547  * List caches associated with a session
548  */
549 static ssize_t caches_show(struct kobject *kobj,
550 			   struct kobj_attribute *attr,
551 			   char *buf)
552 {
553 	ssize_t n = 0, count = 0, limit = PAGE_SIZE;
554 	struct v9fs_session_info *v9ses;
555 
556 	spin_lock(&v9fs_sessionlist_lock);
557 	list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
558 		if (v9ses->cachetag) {
559 			n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
560 			if (n < 0) {
561 				count = n;
562 				break;
563 			}
564 
565 			count += n;
566 			limit -= n;
567 		}
568 	}
569 
570 	spin_unlock(&v9fs_sessionlist_lock);
571 	return count;
572 }
573 
574 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
575 #endif /* CONFIG_9P_FSCACHE */
576 
577 static struct attribute *v9fs_attrs[] = {
578 #ifdef CONFIG_9P_FSCACHE
579 	&v9fs_attr_cache.attr,
580 #endif
581 	NULL,
582 };
583 
584 static const struct attribute_group v9fs_attr_group = {
585 	.attrs = v9fs_attrs,
586 };
587 
588 /**
589  * v9fs_sysfs_init - Initialize the v9fs sysfs interface
590  *
591  */
592 
593 static int __init v9fs_sysfs_init(void)
594 {
595 	v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
596 	if (!v9fs_kobj)
597 		return -ENOMEM;
598 
599 	if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
600 		kobject_put(v9fs_kobj);
601 		return -ENOMEM;
602 	}
603 
604 	return 0;
605 }
606 
607 /**
608  * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
609  *
610  */
611 
612 static void v9fs_sysfs_cleanup(void)
613 {
614 	sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
615 	kobject_put(v9fs_kobj);
616 }
617 
618 static void v9fs_inode_init_once(void *foo)
619 {
620 	struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
621 #ifdef CONFIG_9P_FSCACHE
622 	v9inode->fscache = NULL;
623 #endif
624 	memset(&v9inode->qid, 0, sizeof(v9inode->qid));
625 	inode_init_once(&v9inode->vfs_inode);
626 }
627 
628 /**
629  * v9fs_init_inode_cache - initialize a cache for 9P
630  * Returns 0 on success.
631  */
632 static int v9fs_init_inode_cache(void)
633 {
634 	v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
635 					  sizeof(struct v9fs_inode),
636 					  0, (SLAB_RECLAIM_ACCOUNT|
637 					      SLAB_MEM_SPREAD|SLAB_ACCOUNT),
638 					  v9fs_inode_init_once);
639 	if (!v9fs_inode_cache)
640 		return -ENOMEM;
641 
642 	return 0;
643 }
644 
645 /**
646  * v9fs_destroy_inode_cache - destroy the cache of 9P inode
647  *
648  */
649 static void v9fs_destroy_inode_cache(void)
650 {
651 	/*
652 	 * Make sure all delayed rcu free inodes are flushed before we
653 	 * destroy cache.
654 	 */
655 	rcu_barrier();
656 	kmem_cache_destroy(v9fs_inode_cache);
657 }
658 
659 static int v9fs_cache_register(void)
660 {
661 	int ret;
662 	ret = v9fs_init_inode_cache();
663 	if (ret < 0)
664 		return ret;
665 #ifdef CONFIG_9P_FSCACHE
666 	ret = fscache_register_netfs(&v9fs_cache_netfs);
667 	if (ret < 0)
668 		v9fs_destroy_inode_cache();
669 #endif
670 	return ret;
671 }
672 
673 static void v9fs_cache_unregister(void)
674 {
675 	v9fs_destroy_inode_cache();
676 #ifdef CONFIG_9P_FSCACHE
677 	fscache_unregister_netfs(&v9fs_cache_netfs);
678 #endif
679 }
680 
681 /**
682  * init_v9fs - Initialize module
683  *
684  */
685 
686 static int __init init_v9fs(void)
687 {
688 	int err;
689 	pr_info("Installing v9fs 9p2000 file system support\n");
690 	/* TODO: Setup list of registered trasnport modules */
691 
692 	err = v9fs_cache_register();
693 	if (err < 0) {
694 		pr_err("Failed to register v9fs for caching\n");
695 		return err;
696 	}
697 
698 	err = v9fs_sysfs_init();
699 	if (err < 0) {
700 		pr_err("Failed to register with sysfs\n");
701 		goto out_cache;
702 	}
703 	err = register_filesystem(&v9fs_fs_type);
704 	if (err < 0) {
705 		pr_err("Failed to register filesystem\n");
706 		goto out_sysfs_cleanup;
707 	}
708 
709 	return 0;
710 
711 out_sysfs_cleanup:
712 	v9fs_sysfs_cleanup();
713 
714 out_cache:
715 	v9fs_cache_unregister();
716 
717 	return err;
718 }
719 
720 /**
721  * exit_v9fs - shutdown module
722  *
723  */
724 
725 static void __exit exit_v9fs(void)
726 {
727 	v9fs_sysfs_cleanup();
728 	v9fs_cache_unregister();
729 	unregister_filesystem(&v9fs_fs_type);
730 }
731 
732 module_init(init_v9fs)
733 module_exit(exit_v9fs)
734 
735 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
736 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
737 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
738 MODULE_LICENSE("GPL");
739