0129de2ea31ae514007428c2c9e71188ee405dbf
[releases.git] / v9fs.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  This file contains functions assisting in mapping VFS to 9P2000
4  *
5  *  Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
6  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
7  */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/module.h>
12 #include <linux/errno.h>
13 #include <linux/fs.h>
14 #include <linux/sched.h>
15 #include <linux/cred.h>
16 #include <linux/parser.h>
17 #include <linux/idr.h>
18 #include <linux/slab.h>
19 #include <linux/seq_file.h>
20 #include <net/9p/9p.h>
21 #include <net/9p/client.h>
22 #include <net/9p/transport.h>
23 #include "v9fs.h"
24 #include "v9fs_vfs.h"
25 #include "cache.h"
26
27 static DEFINE_SPINLOCK(v9fs_sessionlist_lock);
28 static LIST_HEAD(v9fs_sessionlist);
29 struct kmem_cache *v9fs_inode_cache;
30
31 /*
32  * Option Parsing (code inspired by NFS code)
33  *  NOTE: each transport will parse its own options
34  */
35
36 enum {
37         /* Options that take integer arguments */
38         Opt_debug, Opt_dfltuid, Opt_dfltgid, Opt_afid,
39         /* String options */
40         Opt_uname, Opt_remotename, Opt_cache, Opt_cachetag,
41         /* Options that take no arguments */
42         Opt_nodevmap,
43         /* Cache options */
44         Opt_cache_loose, Opt_fscache, Opt_mmap,
45         /* Access options */
46         Opt_access, Opt_posixacl,
47         /* Lock timeout option */
48         Opt_locktimeout,
49         /* Error token */
50         Opt_err
51 };
52
53 static const match_table_t tokens = {
54         {Opt_debug, "debug=%x"},
55         {Opt_dfltuid, "dfltuid=%u"},
56         {Opt_dfltgid, "dfltgid=%u"},
57         {Opt_afid, "afid=%u"},
58         {Opt_uname, "uname=%s"},
59         {Opt_remotename, "aname=%s"},
60         {Opt_nodevmap, "nodevmap"},
61         {Opt_cache, "cache=%s"},
62         {Opt_cache_loose, "loose"},
63         {Opt_fscache, "fscache"},
64         {Opt_mmap, "mmap"},
65         {Opt_cachetag, "cachetag=%s"},
66         {Opt_access, "access=%s"},
67         {Opt_posixacl, "posixacl"},
68         {Opt_locktimeout, "locktimeout=%u"},
69         {Opt_err, NULL}
70 };
71
72 static const char *const v9fs_cache_modes[nr__p9_cache_modes] = {
73         [CACHE_NONE]    = "none",
74         [CACHE_MMAP]    = "mmap",
75         [CACHE_LOOSE]   = "loose",
76         [CACHE_FSCACHE] = "fscache",
77 };
78
79 /* Interpret mount options for cache mode */
80 static int get_cache_mode(char *s)
81 {
82         int version = -EINVAL;
83
84         if (!strcmp(s, "loose")) {
85                 version = CACHE_LOOSE;
86                 p9_debug(P9_DEBUG_9P, "Cache mode: loose\n");
87         } else if (!strcmp(s, "fscache")) {
88                 version = CACHE_FSCACHE;
89                 p9_debug(P9_DEBUG_9P, "Cache mode: fscache\n");
90         } else if (!strcmp(s, "mmap")) {
91                 version = CACHE_MMAP;
92                 p9_debug(P9_DEBUG_9P, "Cache mode: mmap\n");
93         } else if (!strcmp(s, "none")) {
94                 version = CACHE_NONE;
95                 p9_debug(P9_DEBUG_9P, "Cache mode: none\n");
96         } else
97                 pr_info("Unknown Cache mode %s\n", s);
98         return version;
99 }
100
101 /*
102  * Display the mount options in /proc/mounts.
103  */
104 int v9fs_show_options(struct seq_file *m, struct dentry *root)
105 {
106         struct v9fs_session_info *v9ses = root->d_sb->s_fs_info;
107
108         if (v9ses->debug)
109                 seq_printf(m, ",debug=%x", v9ses->debug);
110         if (!uid_eq(v9ses->dfltuid, V9FS_DEFUID))
111                 seq_printf(m, ",dfltuid=%u",
112                            from_kuid_munged(&init_user_ns, v9ses->dfltuid));
113         if (!gid_eq(v9ses->dfltgid, V9FS_DEFGID))
114                 seq_printf(m, ",dfltgid=%u",
115                            from_kgid_munged(&init_user_ns, v9ses->dfltgid));
116         if (v9ses->afid != ~0)
117                 seq_printf(m, ",afid=%u", v9ses->afid);
118         if (strcmp(v9ses->uname, V9FS_DEFUSER) != 0)
119                 seq_printf(m, ",uname=%s", v9ses->uname);
120         if (strcmp(v9ses->aname, V9FS_DEFANAME) != 0)
121                 seq_printf(m, ",aname=%s", v9ses->aname);
122         if (v9ses->nodev)
123                 seq_puts(m, ",nodevmap");
124         if (v9ses->cache)
125                 seq_printf(m, ",%s", v9fs_cache_modes[v9ses->cache]);
126 #ifdef CONFIG_9P_FSCACHE
127         if (v9ses->cachetag && v9ses->cache == CACHE_FSCACHE)
128                 seq_printf(m, ",cachetag=%s", v9ses->cachetag);
129 #endif
130
131         switch (v9ses->flags & V9FS_ACCESS_MASK) {
132         case V9FS_ACCESS_USER:
133                 seq_puts(m, ",access=user");
134                 break;
135         case V9FS_ACCESS_ANY:
136                 seq_puts(m, ",access=any");
137                 break;
138         case V9FS_ACCESS_CLIENT:
139                 seq_puts(m, ",access=client");
140                 break;
141         case V9FS_ACCESS_SINGLE:
142                 seq_printf(m, ",access=%u",
143                            from_kuid_munged(&init_user_ns, v9ses->uid));
144                 break;
145         }
146
147         if (v9ses->flags & V9FS_POSIX_ACL)
148                 seq_puts(m, ",posixacl");
149
150         return p9_show_client_options(m, v9ses->clnt);
151 }
152
153 /**
154  * v9fs_parse_options - parse mount options into session structure
155  * @v9ses: existing v9fs session information
156  * @opts: The mount option string
157  *
158  * Return 0 upon success, -ERRNO upon failure.
159  */
160
161 static int v9fs_parse_options(struct v9fs_session_info *v9ses, char *opts)
162 {
163         char *options, *tmp_options;
164         substring_t args[MAX_OPT_ARGS];
165         char *p;
166         int option = 0;
167         char *s;
168         int ret = 0;
169
170         /* setup defaults */
171         v9ses->afid = ~0;
172         v9ses->debug = 0;
173         v9ses->cache = CACHE_NONE;
174 #ifdef CONFIG_9P_FSCACHE
175         v9ses->cachetag = NULL;
176 #endif
177         v9ses->session_lock_timeout = P9_LOCK_TIMEOUT;
178
179         if (!opts)
180                 return 0;
181
182         tmp_options = kstrdup(opts, GFP_KERNEL);
183         if (!tmp_options) {
184                 ret = -ENOMEM;
185                 goto fail_option_alloc;
186         }
187         options = tmp_options;
188
189         while ((p = strsep(&options, ",")) != NULL) {
190                 int token, r;
191
192                 if (!*p)
193                         continue;
194
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
325                                 v9ses->flags |= V9FS_ACCESS_SINGLE;
326                                 r = kstrtouint(s, 10, &uid);
327                                 if (r) {
328                                         ret = r;
329                                         pr_info("Unknown access argument %s: %d\n",
330                                                 s, r);
331                                         kfree(s);
332                                         continue;
333                                 }
334                                 v9ses->uid = make_kuid(current_user_ns(), uid);
335                                 if (!uid_valid(v9ses->uid)) {
336                                         ret = -EINVAL;
337                                         pr_info("Unknown uid %s\n", s);
338                                 }
339                         }
340
341                         kfree(s);
342                         break;
343
344                 case Opt_posixacl:
345 #ifdef CONFIG_9P_FS_POSIX_ACL
346                         v9ses->flags |= V9FS_POSIX_ACL;
347 #else
348                         p9_debug(P9_DEBUG_ERROR,
349                                  "Not defined CONFIG_9P_FS_POSIX_ACL. Ignoring posixacl option\n");
350 #endif
351                         break;
352
353                 case Opt_locktimeout:
354                         r = match_int(&args[0], &option);
355                         if (r < 0) {
356                                 p9_debug(P9_DEBUG_ERROR,
357                                          "integer field, but no integer?\n");
358                                 ret = r;
359                                 continue;
360                         }
361                         if (option < 1) {
362                                 p9_debug(P9_DEBUG_ERROR,
363                                          "locktimeout must be a greater than zero integer.\n");
364                                 ret = -EINVAL;
365                                 continue;
366                         }
367                         v9ses->session_lock_timeout = (long)option * HZ;
368                         break;
369
370                 default:
371                         continue;
372                 }
373         }
374
375 free_and_return:
376         kfree(tmp_options);
377 fail_option_alloc:
378         return ret;
379 }
380
381 /**
382  * v9fs_session_init - initialize session
383  * @v9ses: session information structure
384  * @dev_name: device being mounted
385  * @data: options
386  *
387  */
388
389 struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
390                   const char *dev_name, char *data)
391 {
392         struct p9_fid *fid;
393         int rc = -ENOMEM;
394
395         v9ses->uname = kstrdup(V9FS_DEFUSER, GFP_KERNEL);
396         if (!v9ses->uname)
397                 goto err_names;
398
399         v9ses->aname = kstrdup(V9FS_DEFANAME, GFP_KERNEL);
400         if (!v9ses->aname)
401                 goto err_names;
402         init_rwsem(&v9ses->rename_sem);
403
404         v9ses->uid = INVALID_UID;
405         v9ses->dfltuid = V9FS_DEFUID;
406         v9ses->dfltgid = V9FS_DEFGID;
407
408         v9ses->clnt = p9_client_create(dev_name, data);
409         if (IS_ERR(v9ses->clnt)) {
410                 rc = PTR_ERR(v9ses->clnt);
411                 p9_debug(P9_DEBUG_ERROR, "problem initializing 9p client\n");
412                 goto err_names;
413         }
414
415         v9ses->flags = V9FS_ACCESS_USER;
416
417         if (p9_is_proto_dotl(v9ses->clnt)) {
418                 v9ses->flags = V9FS_ACCESS_CLIENT;
419                 v9ses->flags |= V9FS_PROTO_2000L;
420         } else if (p9_is_proto_dotu(v9ses->clnt)) {
421                 v9ses->flags |= V9FS_PROTO_2000U;
422         }
423
424         rc = v9fs_parse_options(v9ses, data);
425         if (rc < 0)
426                 goto err_clnt;
427
428         v9ses->maxdata = v9ses->clnt->msize - P9_IOHDRSZ;
429
430         if (!v9fs_proto_dotl(v9ses) &&
431             ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
432                 /*
433                  * We support ACCESS_CLIENT only for dotl.
434                  * Fall back to ACCESS_USER
435                  */
436                 v9ses->flags &= ~V9FS_ACCESS_MASK;
437                 v9ses->flags |= V9FS_ACCESS_USER;
438         }
439         /*FIXME !! */
440         /* for legacy mode, fall back to V9FS_ACCESS_ANY */
441         if (!(v9fs_proto_dotu(v9ses) || v9fs_proto_dotl(v9ses)) &&
442                 ((v9ses->flags&V9FS_ACCESS_MASK) == V9FS_ACCESS_USER)) {
443
444                 v9ses->flags &= ~V9FS_ACCESS_MASK;
445                 v9ses->flags |= V9FS_ACCESS_ANY;
446                 v9ses->uid = INVALID_UID;
447         }
448         if (!v9fs_proto_dotl(v9ses) ||
449                 !((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_CLIENT)) {
450                 /*
451                  * We support ACL checks on clinet only if the protocol is
452                  * 9P2000.L and access is V9FS_ACCESS_CLIENT.
453                  */
454                 v9ses->flags &= ~V9FS_ACL_MASK;
455         }
456
457         fid = p9_client_attach(v9ses->clnt, NULL, v9ses->uname, INVALID_UID,
458                                                         v9ses->aname);
459         if (IS_ERR(fid)) {
460                 rc = PTR_ERR(fid);
461                 p9_debug(P9_DEBUG_ERROR, "cannot attach\n");
462                 goto err_clnt;
463         }
464
465         if ((v9ses->flags & V9FS_ACCESS_MASK) == V9FS_ACCESS_SINGLE)
466                 fid->uid = v9ses->uid;
467         else
468                 fid->uid = INVALID_UID;
469
470 #ifdef CONFIG_9P_FSCACHE
471         /* register the session for caching */
472         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
473                 rc = v9fs_cache_session_get_cookie(v9ses, dev_name);
474                 if (rc < 0)
475                         goto err_clnt;
476         }
477 #endif
478         spin_lock(&v9fs_sessionlist_lock);
479         list_add(&v9ses->slist, &v9fs_sessionlist);
480         spin_unlock(&v9fs_sessionlist_lock);
481
482         return fid;
483
484 err_clnt:
485 #ifdef CONFIG_9P_FSCACHE
486         kfree(v9ses->cachetag);
487 #endif
488         p9_client_destroy(v9ses->clnt);
489 err_names:
490         kfree(v9ses->uname);
491         kfree(v9ses->aname);
492         return ERR_PTR(rc);
493 }
494
495 /**
496  * v9fs_session_close - shutdown a session
497  * @v9ses: session information structure
498  *
499  */
500
501 void v9fs_session_close(struct v9fs_session_info *v9ses)
502 {
503         if (v9ses->clnt) {
504                 p9_client_destroy(v9ses->clnt);
505                 v9ses->clnt = NULL;
506         }
507
508 #ifdef CONFIG_9P_FSCACHE
509         fscache_relinquish_volume(v9fs_session_cache(v9ses), NULL, false);
510         kfree(v9ses->cachetag);
511 #endif
512         kfree(v9ses->uname);
513         kfree(v9ses->aname);
514
515         spin_lock(&v9fs_sessionlist_lock);
516         list_del(&v9ses->slist);
517         spin_unlock(&v9fs_sessionlist_lock);
518 }
519
520 /**
521  * v9fs_session_cancel - terminate a session
522  * @v9ses: session to terminate
523  *
524  * mark transport as disconnected and cancel all pending requests.
525  */
526
527 void v9fs_session_cancel(struct v9fs_session_info *v9ses)
528 {
529         p9_debug(P9_DEBUG_ERROR, "cancel session %p\n", v9ses);
530         p9_client_disconnect(v9ses->clnt);
531 }
532
533 /**
534  * v9fs_session_begin_cancel - Begin terminate of a session
535  * @v9ses: session to terminate
536  *
537  * After this call we don't allow any request other than clunk.
538  */
539
540 void v9fs_session_begin_cancel(struct v9fs_session_info *v9ses)
541 {
542         p9_debug(P9_DEBUG_ERROR, "begin cancel session %p\n", v9ses);
543         p9_client_begin_disconnect(v9ses->clnt);
544 }
545
546 extern int v9fs_error_init(void);
547
548 static struct kobject *v9fs_kobj;
549
550 #ifdef CONFIG_9P_FSCACHE
551 /*
552  * List caches associated with a session
553  */
554 static ssize_t caches_show(struct kobject *kobj,
555                            struct kobj_attribute *attr,
556                            char *buf)
557 {
558         ssize_t n = 0, count = 0, limit = PAGE_SIZE;
559         struct v9fs_session_info *v9ses;
560
561         spin_lock(&v9fs_sessionlist_lock);
562         list_for_each_entry(v9ses, &v9fs_sessionlist, slist) {
563                 if (v9ses->cachetag) {
564                         n = snprintf(buf, limit, "%s\n", v9ses->cachetag);
565                         if (n < 0) {
566                                 count = n;
567                                 break;
568                         }
569
570                         count += n;
571                         limit -= n;
572                 }
573         }
574
575         spin_unlock(&v9fs_sessionlist_lock);
576         return count;
577 }
578
579 static struct kobj_attribute v9fs_attr_cache = __ATTR_RO(caches);
580 #endif /* CONFIG_9P_FSCACHE */
581
582 static struct attribute *v9fs_attrs[] = {
583 #ifdef CONFIG_9P_FSCACHE
584         &v9fs_attr_cache.attr,
585 #endif
586         NULL,
587 };
588
589 static const struct attribute_group v9fs_attr_group = {
590         .attrs = v9fs_attrs,
591 };
592
593 /**
594  * v9fs_sysfs_init - Initialize the v9fs sysfs interface
595  *
596  */
597
598 static int __init v9fs_sysfs_init(void)
599 {
600         v9fs_kobj = kobject_create_and_add("9p", fs_kobj);
601         if (!v9fs_kobj)
602                 return -ENOMEM;
603
604         if (sysfs_create_group(v9fs_kobj, &v9fs_attr_group)) {
605                 kobject_put(v9fs_kobj);
606                 return -ENOMEM;
607         }
608
609         return 0;
610 }
611
612 /**
613  * v9fs_sysfs_cleanup - Unregister the v9fs sysfs interface
614  *
615  */
616
617 static void v9fs_sysfs_cleanup(void)
618 {
619         sysfs_remove_group(v9fs_kobj, &v9fs_attr_group);
620         kobject_put(v9fs_kobj);
621 }
622
623 static void v9fs_inode_init_once(void *foo)
624 {
625         struct v9fs_inode *v9inode = (struct v9fs_inode *)foo;
626
627         memset(&v9inode->qid, 0, sizeof(v9inode->qid));
628         inode_init_once(&v9inode->netfs.inode);
629 }
630
631 /**
632  * v9fs_init_inode_cache - initialize a cache for 9P
633  * Returns 0 on success.
634  */
635 static int v9fs_init_inode_cache(void)
636 {
637         v9fs_inode_cache = kmem_cache_create("v9fs_inode_cache",
638                                           sizeof(struct v9fs_inode),
639                                           0, (SLAB_RECLAIM_ACCOUNT|
640                                               SLAB_MEM_SPREAD|SLAB_ACCOUNT),
641                                           v9fs_inode_init_once);
642         if (!v9fs_inode_cache)
643                 return -ENOMEM;
644
645         return 0;
646 }
647
648 /**
649  * v9fs_destroy_inode_cache - destroy the cache of 9P inode
650  *
651  */
652 static void v9fs_destroy_inode_cache(void)
653 {
654         /*
655          * Make sure all delayed rcu free inodes are flushed before we
656          * destroy cache.
657          */
658         rcu_barrier();
659         kmem_cache_destroy(v9fs_inode_cache);
660 }
661
662 static int v9fs_cache_register(void)
663 {
664         int ret;
665
666         ret = v9fs_init_inode_cache();
667         if (ret < 0)
668                 return ret;
669         return ret;
670 }
671
672 static void v9fs_cache_unregister(void)
673 {
674         v9fs_destroy_inode_cache();
675 }
676
677 /**
678  * init_v9fs - Initialize module
679  *
680  */
681
682 static int __init init_v9fs(void)
683 {
684         int err;
685
686         pr_info("Installing v9fs 9p2000 file system support\n");
687         /* TODO: Setup list of registered trasnport modules */
688
689         err = v9fs_cache_register();
690         if (err < 0) {
691                 pr_err("Failed to register v9fs for caching\n");
692                 return err;
693         }
694
695         err = v9fs_sysfs_init();
696         if (err < 0) {
697                 pr_err("Failed to register with sysfs\n");
698                 goto out_cache;
699         }
700         err = register_filesystem(&v9fs_fs_type);
701         if (err < 0) {
702                 pr_err("Failed to register filesystem\n");
703                 goto out_sysfs_cleanup;
704         }
705
706         return 0;
707
708 out_sysfs_cleanup:
709         v9fs_sysfs_cleanup();
710
711 out_cache:
712         v9fs_cache_unregister();
713
714         return err;
715 }
716
717 /**
718  * exit_v9fs - shutdown module
719  *
720  */
721
722 static void __exit exit_v9fs(void)
723 {
724         v9fs_sysfs_cleanup();
725         v9fs_cache_unregister();
726         unregister_filesystem(&v9fs_fs_type);
727 }
728
729 module_init(init_v9fs)
730 module_exit(exit_v9fs)
731
732 MODULE_AUTHOR("Latchesar Ionkov <lucho@ionkov.net>");
733 MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
734 MODULE_AUTHOR("Ron Minnich <rminnich@lanl.gov>");
735 MODULE_LICENSE("GPL");