xref: /openbmc/linux/fs/9p/v9fs.c (revision cfbb9be8) 
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 #endif
296 			break;
297 		case Opt_cache:
298 			s = match_strdup(&args[0]);
299 			if (!s) {
300 				ret = -ENOMEM;
301 				p9_debug(P9_DEBUG_ERROR,
302 					 "problem allocating copy of cache arg\n");
303 				goto free_and_return;
304 			}
305 			ret = get_cache_mode(s);
306 			if (ret == -EINVAL) {
307 				kfree(s);
308 				goto free_and_return;
309 			}
310 
311 			v9ses->cache = ret;
312 			kfree(s);
313 			break;
314 
315 		case Opt_access:
316 			s = match_strdup(&args[0]);
317 			if (!s) {
318 				ret = -ENOMEM;
319 				p9_debug(P9_DEBUG_ERROR,
320 					 "problem allocating copy of access arg\n");
321 				goto free_and_return;
322 			}
323 
324 			v9ses->flags &= ~V9FS_ACCESS_MASK;
325 			if (strcmp(s, "user") == 0)
326 				v9ses->flags |= V9FS_ACCESS_USER;
327 			else if (strcmp(s, "any") == 0)
328 				v9ses->flags |= V9FS_ACCESS_ANY;
329 			else if (strcmp(s, "client") == 0) {
330 				v9ses->flags |= V9FS_ACCESS_CLIENT;
331 			} else {
332 				uid_t uid;
333 				v9ses->flags |= V9FS_ACCESS_SINGLE;
334 				uid = simple_strtoul(s, &e, 10);
335 				if (*e != '\0') {
336 					ret = -EINVAL;
337 					pr_info("Unknown access argument %s\n",
338 						s);
339 					kfree(s);
340 					goto free_and_return;
341 				}
342 				v9ses->uid = make_kuid(current_user_ns(), uid);
343 				if (!uid_valid(v9ses->uid)) {
344 					ret = -EINVAL;
345 					pr_info("Uknown uid %s\n", s);
346 					kfree(s);
347 					goto free_and_return;
348 				}
349 			}
350 
351 			kfree(s);
352 			break;
353 
354 		case Opt_posixacl:
355 #ifdef CONFIG_9P_FS_POSIX_ACL
356 			v9ses->flags |= V9FS_POSIX_ACL;
357 #else
358 			p9_debug(P9_DEBUG_ERROR,
359 				 "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
360 #endif
361 			break;
362 
363 		default:
364 			continue;
365 		}
366 	}
367 
368 free_and_return:
369 	kfree(tmp_options);
370 fail_option_alloc:
371 	return ret;
372 }
373 
374 /**
375  * v9fs_session_init - initialize session
376  * @v9ses: session information structure
377  * @dev_name: device being mounted
378  * @data: options
379  *
380  */
381 
382 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
383 		  const char *dev_name, char *data)
384 {
385 	struct p9_fid *fid;
386 	int rc = -ENOMEM;
387 
388 	v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
389 	if (!v9ses->uname)
390 		goto err_names;
391 
392 	v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
393 	if (!v9ses->aname)
394 		goto err_names;
395 	init_rwsem(&v9ses->rename_sem);
396 
397 	v9ses->uid = INVALID_UID;
398 	v9ses->dfltuid = V9FS_DEFUID;
399 	v9ses->dfltgid = V9FS_DEFGID;
400 
401 	v9ses->clnt = p9_client_create(dev_name, data);
402 	if (IS_ERR(v9ses->clnt)) {
403 		rc = PTR_ERR(v9ses->clnt);
404 		p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
405 		goto err_names;
406 	}
407 
408 	v9ses->flags = V9FS_ACCESS_USER;
409 
410 	if (p9_is_proto_dotl(v9ses->clnt)) {
411 		v9ses->flags = V9FS_ACCESS_CLIENT;
412 		v9ses->flags |= V9FS_PROTO_2000L;
413 	} else if (p9_is_proto_dotu(v9ses->clnt)) {
414 		v9ses->flags |= V9FS_PROTO_2000U;
415 	}
416 
417 	rc = v9fs_parse_options(v9ses, data);
418 	if (rc < 0)
419 		goto err_clnt;
420 
421 	v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
422 
423 	if (!v9fs_proto_dotl(v9ses) &&
424 	    ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
425 		/*
426 		 * We support ACCESS_CLIENT only for dotl.
427 		 * Fall back to ACCESS_USER
428 		 */
429 		v9ses->flags &= ~V9FS_ACCESS_MASK;
430 		v9ses->flags |= V9FS_ACCESS_USER;
431 	}
432 	/*FIXME !! */
433 	/* for legacy mode, fall back to V9FS_ACCESS_ANY */
434 	if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
435 		((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
436 
437 		v9ses->flags &= ~V9FS_ACCESS_MASK;
438 		v9ses->flags |= V9FS_ACCESS_ANY;
439 		v9ses->uid = INVALID_UID;
440 	}
441 	if (!v9fs_proto_dotl(v9ses) ||
442 		!((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
443 		/*
444 		 * We support ACL checks on clinet only if the protocol is
445 		 * 9P2000.L and access is V9FS_ACCESS_CLIENT.
446 		 */
447 		v9ses->flags &= ~V9FS_ACL_MASK;
448 	}
449 
450 	fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
451 							v9ses->aname);
452 	if (IS_ERR(fid)) {
453 		rc = PTR_ERR(fid);
454 		p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
455 		goto err_clnt;
456 	}
457 
458 	if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
459 		fid->uid = v9ses->uid;
460 	else
461 		fid->uid = INVALID_UID;
462 
463 #ifdef CONFIG_9P_FSCACHE
464 	/* register the session for caching */
465 	v9fs_cache_session_get_cookie(v9ses);
466 #endif
467 	spin_lock(&v9fs_sessionlist_lock);
468 	list_add(&v9ses->slist, &v9fs_sessionlist);
469 	spin_unlock(&v9fs_sessionlist_lock);
470 
471 	return fid;
472 
473 err_clnt:
474 	p9_client_destroy(v9ses->clnt);
475 err_names:
476 	kfree(v9ses->uname);
477 	kfree(v9ses->aname);
478 	return ERR_PTR(rc);
479 }
480 
481 /**
482  * v9fs_session_close - shutdown a session
483  * @v9ses: session information structure
484  *
485  */
486 
487 void v9fs_session_close(struct v9fs_session_info *v9ses)
488 {
489 	if (v9ses->clnt) {
490 		p9_client_destroy(v9ses->clnt);
491 		v9ses->clnt = NULL;
492 	}
493 
494 #ifdef CONFIG_9P_FSCACHE
495 	if (v9ses->fscache) {
496 		v9fs_cache_session_put_cookie(v9ses);
497 		kfree(v9ses->cachetag);
498 	}
499 #endif
500 	kfree(v9ses->uname);
501 	kfree(v9ses->aname);
502 
503 	spin_lock(&v9fs_sessionlist_lock);
504 	list_del(&v9ses->slist);
505 	spin_unlock(&v9fs_sessionlist_lock);
506 }
507 
508 /**
509  * v9fs_session_cancel - terminate a session
510  * @v9ses: session to terminate
511  *
512  * mark transport as disconnected and cancel all pending requests.
513  */
514 
515 void v9fs_session_cancel(struct v9fs_session_info *v9ses) {
516 	p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
517 	p9_client_disconnect(v9ses->clnt);
518 }
519 
520 /**
521  * v9fs_session_begin_cancel - Begin terminate of a session
522  * @v9ses: session to terminate
523  *
524  * After this call we don't allow any request other than clunk.
525  */
526 
527 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
528 {
529 	p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
530 	p9_client_begin_disconnect(v9ses->clnt);
531 }
532 
533 extern int v9fs_error_init(void);
534 
535 static struct kobject *v9fs_kobj;
536 
537 #ifdef CONFIG_9P_FSCACHE
538 /**
539  * caches_show - list caches associated with a session
540  *
541  * Returns the size of buffer written.
542  */
543 
544 static ssize_t caches_show(struct kobject *kobj,
545 			   struct kobj_attribute *attr,
546 			   char *buf)
547 {
548 	ssize_t n = 0, count = 0, limit = PAGE_SIZE;
549 	struct v9fs_session_info *v9ses;
550 
551 	spin_lock(&v9fs_sessionlist_lock);
552 	list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
553 		if (v9ses->cachetag) {
554 			n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
555 			if (n < 0) {
556 				count = n;
557 				break;
558 			}
559 
560 			count += n;
561 			limit -= n;
562 		}
563 	}
564 
565 	spin_unlock(&v9fs_sessionlist_lock);
566 	return count;
567 }
568 
569 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
570 #endif /* CONFIG_9P_FSCACHE */
571 
572 static struct attribute *v9fs_attrs[] = {
573 #ifdef CONFIG_9P_FSCACHE
574 	&v9fs_attr_cache.attr,
575 #endif
576 	NULL,
577 };
578 
579 static struct attribute_group v9fs_attr_group = {
580 	.attrs = v9fs_attrs,
581 };
582 
583 /**
584  * v9fs_sysfs_init - Initialize the v9fs sysfs interface
585  *
586  */
587 
588 static int __init v9fs_sysfs_init(void)
589 {
590 	v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
591 	if (!v9fs_kobj)
592 		return -ENOMEM;
593 
594 	if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
595 		kobject_put(v9fs_kobj);
596 		return -ENOMEM;
597 	}
598 
599 	return 0;
600 }
601 
602 /**
603  * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
604  *
605  */
606 
607 static void v9fs_sysfs_cleanup(void)
608 {
609 	sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
610 	kobject_put(v9fs_kobj);
611 }
612 
613 static void v9fs_inode_init_once(void *foo)
614 {
615 	struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
616 #ifdef CONFIG_9P_FSCACHE
617 	v9inode->fscache = NULL;
618 #endif
619 	memset(&v9inode->qid, 0, sizeof(v9inode->qid));
620 	inode_init_once(&v9inode->vfs_inode);
621 }
622 
623 /**
624  * v9fs_init_inode_cache - initialize a cache for 9P
625  * Returns 0 on success.
626  */
627 static int v9fs_init_inode_cache(void)
628 {
629 	v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
630 					  sizeof(struct v9fs_inode),
631 					  0, (SLAB_RECLAIM_ACCOUNT|
632 					      SLAB_MEM_SPREAD|SLAB_ACCOUNT),
633 					  v9fs_inode_init_once);
634 	if (!v9fs_inode_cache)
635 		return -ENOMEM;
636 
637 	return 0;
638 }
639 
640 /**
641  * v9fs_destroy_inode_cache - destroy the cache of 9P inode
642  *
643  */
644 static void v9fs_destroy_inode_cache(void)
645 {
646 	/*
647 	 * Make sure all delayed rcu free inodes are flushed before we
648 	 * destroy cache.
649 	 */
650 	rcu_barrier();
651 	kmem_cache_destroy(v9fs_inode_cache);
652 }
653 
654 static int v9fs_cache_register(void)
655 {
656 	int ret;
657 	ret = v9fs_init_inode_cache();
658 	if (ret < 0)
659 		return ret;
660 #ifdef CONFIG_9P_FSCACHE
661 	ret = fscache_register_netfs(&v9fs_cache_netfs);
662 	if (ret < 0)
663 		v9fs_destroy_inode_cache();
664 #endif
665 	return ret;
666 }
667 
668 static void v9fs_cache_unregister(void)
669 {
670 	v9fs_destroy_inode_cache();
671 #ifdef CONFIG_9P_FSCACHE
672 	fscache_unregister_netfs(&v9fs_cache_netfs);
673 #endif
674 }
675 
676 /**
677  * init_v9fs - Initialize module
678  *
679  */
680 
681 static int __init init_v9fs(void)
682 {
683 	int err;
684 	pr_info("Installing v9fs 9p2000 file system support\n");
685 	/* TODO: Setup list of registered trasnport modules */
686 
687 	err = v9fs_cache_register();
688 	if (err < 0) {
689 		pr_err("Failed to register v9fs for caching\n");
690 		return err;
691 	}
692 
693 	err = v9fs_sysfs_init();
694 	if (err < 0) {
695 		pr_err("Failed to register with sysfs\n");
696 		goto out_cache;
697 	}
698 	err = register_filesystem(&v9fs_fs_type);
699 	if (err < 0) {
700 		pr_err("Failed to register filesystem\n");
701 		goto out_sysfs_cleanup;
702 	}
703 
704 	return 0;
705 
706 out_sysfs_cleanup:
707 	v9fs_sysfs_cleanup();
708 
709 out_cache:
710 	v9fs_cache_unregister();
711 
712 	return err;
713 }
714 
715 /**
716  * exit_v9fs - shutdown module
717  *
718  */
719 
720 static void __exit exit_v9fs(void)
721 {
722 	v9fs_sysfs_cleanup();
723 	v9fs_cache_unregister();
724 	unregister_filesystem(&v9fs_fs_type);
725 }
726 
727 module_init(init_v9fs)
728 module_exit(exit_v9fs)
729 
730 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
731 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
732 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
733 MODULE_LICENSE("GPL");
734