[PATCH] VFS: Permit filesystem to perform statfs with a known root dentry
[safe/jmp/linux-2.6] / fs / fuse / inode.c
1 /*
2   FUSE: Filesystem in Userspace
3   Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
4
5   This program can be distributed under the terms of the GNU GPL.
6   See the file COPYING.
7 */
8
9 #include "fuse_i.h"
10
11 #include <linux/pagemap.h>
12 #include <linux/slab.h>
13 #include <linux/file.h>
14 #include <linux/mount.h>
15 #include <linux/seq_file.h>
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/parser.h>
19 #include <linux/statfs.h>
20
21 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
22 MODULE_DESCRIPTION("Filesystem in Userspace");
23 MODULE_LICENSE("GPL");
24
25 static kmem_cache_t *fuse_inode_cachep;
26 static struct subsystem connections_subsys;
27
28 struct fuse_conn_attr {
29         struct attribute attr;
30         ssize_t (*show)(struct fuse_conn *, char *);
31         ssize_t (*store)(struct fuse_conn *, const char *, size_t);
32 };
33
34 #define FUSE_SUPER_MAGIC 0x65735546
35
36 struct fuse_mount_data {
37         int fd;
38         unsigned rootmode;
39         unsigned user_id;
40         unsigned group_id;
41         unsigned fd_present : 1;
42         unsigned rootmode_present : 1;
43         unsigned user_id_present : 1;
44         unsigned group_id_present : 1;
45         unsigned flags;
46         unsigned max_read;
47 };
48
49 static struct inode *fuse_alloc_inode(struct super_block *sb)
50 {
51         struct inode *inode;
52         struct fuse_inode *fi;
53
54         inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
55         if (!inode)
56                 return NULL;
57
58         fi = get_fuse_inode(inode);
59         fi->i_time = jiffies - 1;
60         fi->nodeid = 0;
61         fi->nlookup = 0;
62         fi->forget_req = fuse_request_alloc();
63         if (!fi->forget_req) {
64                 kmem_cache_free(fuse_inode_cachep, inode);
65                 return NULL;
66         }
67
68         return inode;
69 }
70
71 static void fuse_destroy_inode(struct inode *inode)
72 {
73         struct fuse_inode *fi = get_fuse_inode(inode);
74         if (fi->forget_req)
75                 fuse_request_free(fi->forget_req);
76         kmem_cache_free(fuse_inode_cachep, inode);
77 }
78
79 static void fuse_read_inode(struct inode *inode)
80 {
81         /* No op */
82 }
83
84 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
85                       unsigned long nodeid, u64 nlookup)
86 {
87         struct fuse_forget_in *inarg = &req->misc.forget_in;
88         inarg->nlookup = nlookup;
89         req->in.h.opcode = FUSE_FORGET;
90         req->in.h.nodeid = nodeid;
91         req->in.numargs = 1;
92         req->in.args[0].size = sizeof(struct fuse_forget_in);
93         req->in.args[0].value = inarg;
94         request_send_noreply(fc, req);
95 }
96
97 static void fuse_clear_inode(struct inode *inode)
98 {
99         if (inode->i_sb->s_flags & MS_ACTIVE) {
100                 struct fuse_conn *fc = get_fuse_conn(inode);
101                 struct fuse_inode *fi = get_fuse_inode(inode);
102                 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
103                 fi->forget_req = NULL;
104         }
105 }
106
107 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
108 {
109         if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
110                 invalidate_inode_pages(inode->i_mapping);
111
112         inode->i_ino     = attr->ino;
113         inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
114         inode->i_nlink   = attr->nlink;
115         inode->i_uid     = attr->uid;
116         inode->i_gid     = attr->gid;
117         i_size_write(inode, attr->size);
118         inode->i_blksize = PAGE_CACHE_SIZE;
119         inode->i_blocks  = attr->blocks;
120         inode->i_atime.tv_sec   = attr->atime;
121         inode->i_atime.tv_nsec  = attr->atimensec;
122         inode->i_mtime.tv_sec   = attr->mtime;
123         inode->i_mtime.tv_nsec  = attr->mtimensec;
124         inode->i_ctime.tv_sec   = attr->ctime;
125         inode->i_ctime.tv_nsec  = attr->ctimensec;
126 }
127
128 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
129 {
130         inode->i_mode = attr->mode & S_IFMT;
131         i_size_write(inode, attr->size);
132         if (S_ISREG(inode->i_mode)) {
133                 fuse_init_common(inode);
134                 fuse_init_file_inode(inode);
135         } else if (S_ISDIR(inode->i_mode))
136                 fuse_init_dir(inode);
137         else if (S_ISLNK(inode->i_mode))
138                 fuse_init_symlink(inode);
139         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
140                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
141                 fuse_init_common(inode);
142                 init_special_inode(inode, inode->i_mode,
143                                    new_decode_dev(attr->rdev));
144         } else
145                 BUG();
146 }
147
148 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
149 {
150         unsigned long nodeid = *(unsigned long *) _nodeidp;
151         if (get_node_id(inode) == nodeid)
152                 return 1;
153         else
154                 return 0;
155 }
156
157 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
158 {
159         unsigned long nodeid = *(unsigned long *) _nodeidp;
160         get_fuse_inode(inode)->nodeid = nodeid;
161         return 0;
162 }
163
164 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
165                         int generation, struct fuse_attr *attr)
166 {
167         struct inode *inode;
168         struct fuse_inode *fi;
169         struct fuse_conn *fc = get_fuse_conn_super(sb);
170         int retried = 0;
171
172  retry:
173         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
174         if (!inode)
175                 return NULL;
176
177         if ((inode->i_state & I_NEW)) {
178                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
179                 inode->i_generation = generation;
180                 inode->i_data.backing_dev_info = &fc->bdi;
181                 fuse_init_inode(inode, attr);
182                 unlock_new_inode(inode);
183         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
184                 BUG_ON(retried);
185                 /* Inode has changed type, any I/O on the old should fail */
186                 make_bad_inode(inode);
187                 iput(inode);
188                 retried = 1;
189                 goto retry;
190         }
191
192         fi = get_fuse_inode(inode);
193         fi->nlookup ++;
194         fuse_change_attributes(inode, attr);
195         return inode;
196 }
197
198 static void fuse_umount_begin(struct super_block *sb)
199 {
200         fuse_abort_conn(get_fuse_conn_super(sb));
201 }
202
203 static void fuse_put_super(struct super_block *sb)
204 {
205         struct fuse_conn *fc = get_fuse_conn_super(sb);
206
207         down_write(&fc->sbput_sem);
208         while (!list_empty(&fc->background))
209                 fuse_release_background(fc,
210                                         list_entry(fc->background.next,
211                                                    struct fuse_req, bg_entry));
212
213         spin_lock(&fc->lock);
214         fc->mounted = 0;
215         fc->connected = 0;
216         spin_unlock(&fc->lock);
217         up_write(&fc->sbput_sem);
218         /* Flush all readers on this fs */
219         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
220         wake_up_all(&fc->waitq);
221         kobject_del(&fc->kobj);
222         kobject_put(&fc->kobj);
223 }
224
225 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
226 {
227         stbuf->f_type    = FUSE_SUPER_MAGIC;
228         stbuf->f_bsize   = attr->bsize;
229         stbuf->f_frsize  = attr->frsize;
230         stbuf->f_blocks  = attr->blocks;
231         stbuf->f_bfree   = attr->bfree;
232         stbuf->f_bavail  = attr->bavail;
233         stbuf->f_files   = attr->files;
234         stbuf->f_ffree   = attr->ffree;
235         stbuf->f_namelen = attr->namelen;
236         /* fsid is left zero */
237 }
238
239 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
240 {
241         struct super_block *sb = dentry->d_sb;
242         struct fuse_conn *fc = get_fuse_conn_super(sb);
243         struct fuse_req *req;
244         struct fuse_statfs_out outarg;
245         int err;
246
247         req = fuse_get_req(fc);
248         if (IS_ERR(req))
249                 return PTR_ERR(req);
250
251         memset(&outarg, 0, sizeof(outarg));
252         req->in.numargs = 0;
253         req->in.h.opcode = FUSE_STATFS;
254         req->out.numargs = 1;
255         req->out.args[0].size =
256                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
257         req->out.args[0].value = &outarg;
258         request_send(fc, req);
259         err = req->out.h.error;
260         if (!err)
261                 convert_fuse_statfs(buf, &outarg.st);
262         fuse_put_request(fc, req);
263         return err;
264 }
265
266 enum {
267         OPT_FD,
268         OPT_ROOTMODE,
269         OPT_USER_ID,
270         OPT_GROUP_ID,
271         OPT_DEFAULT_PERMISSIONS,
272         OPT_ALLOW_OTHER,
273         OPT_MAX_READ,
274         OPT_ERR
275 };
276
277 static match_table_t tokens = {
278         {OPT_FD,                        "fd=%u"},
279         {OPT_ROOTMODE,                  "rootmode=%o"},
280         {OPT_USER_ID,                   "user_id=%u"},
281         {OPT_GROUP_ID,                  "group_id=%u"},
282         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
283         {OPT_ALLOW_OTHER,               "allow_other"},
284         {OPT_MAX_READ,                  "max_read=%u"},
285         {OPT_ERR,                       NULL}
286 };
287
288 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
289 {
290         char *p;
291         memset(d, 0, sizeof(struct fuse_mount_data));
292         d->max_read = ~0;
293
294         while ((p = strsep(&opt, ",")) != NULL) {
295                 int token;
296                 int value;
297                 substring_t args[MAX_OPT_ARGS];
298                 if (!*p)
299                         continue;
300
301                 token = match_token(p, tokens, args);
302                 switch (token) {
303                 case OPT_FD:
304                         if (match_int(&args[0], &value))
305                                 return 0;
306                         d->fd = value;
307                         d->fd_present = 1;
308                         break;
309
310                 case OPT_ROOTMODE:
311                         if (match_octal(&args[0], &value))
312                                 return 0;
313                         d->rootmode = value;
314                         d->rootmode_present = 1;
315                         break;
316
317                 case OPT_USER_ID:
318                         if (match_int(&args[0], &value))
319                                 return 0;
320                         d->user_id = value;
321                         d->user_id_present = 1;
322                         break;
323
324                 case OPT_GROUP_ID:
325                         if (match_int(&args[0], &value))
326                                 return 0;
327                         d->group_id = value;
328                         d->group_id_present = 1;
329                         break;
330
331                 case OPT_DEFAULT_PERMISSIONS:
332                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
333                         break;
334
335                 case OPT_ALLOW_OTHER:
336                         d->flags |= FUSE_ALLOW_OTHER;
337                         break;
338
339                 case OPT_MAX_READ:
340                         if (match_int(&args[0], &value))
341                                 return 0;
342                         d->max_read = value;
343                         break;
344
345                 default:
346                         return 0;
347                 }
348         }
349
350         if (!d->fd_present || !d->rootmode_present ||
351             !d->user_id_present || !d->group_id_present)
352                 return 0;
353
354         return 1;
355 }
356
357 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
358 {
359         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
360
361         seq_printf(m, ",user_id=%u", fc->user_id);
362         seq_printf(m, ",group_id=%u", fc->group_id);
363         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
364                 seq_puts(m, ",default_permissions");
365         if (fc->flags & FUSE_ALLOW_OTHER)
366                 seq_puts(m, ",allow_other");
367         if (fc->max_read != ~0)
368                 seq_printf(m, ",max_read=%u", fc->max_read);
369         return 0;
370 }
371
372 static void fuse_conn_release(struct kobject *kobj)
373 {
374         kfree(get_fuse_conn_kobj(kobj));
375 }
376
377 static struct fuse_conn *new_conn(void)
378 {
379         struct fuse_conn *fc;
380
381         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
382         if (fc) {
383                 spin_lock_init(&fc->lock);
384                 init_waitqueue_head(&fc->waitq);
385                 init_waitqueue_head(&fc->blocked_waitq);
386                 INIT_LIST_HEAD(&fc->pending);
387                 INIT_LIST_HEAD(&fc->processing);
388                 INIT_LIST_HEAD(&fc->io);
389                 INIT_LIST_HEAD(&fc->background);
390                 init_rwsem(&fc->sbput_sem);
391                 kobj_set_kset_s(fc, connections_subsys);
392                 kobject_init(&fc->kobj);
393                 atomic_set(&fc->num_waiting, 0);
394                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
395                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
396                 fc->reqctr = 0;
397                 fc->blocked = 1;
398         }
399         return fc;
400 }
401
402 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
403 {
404         struct fuse_attr attr;
405         memset(&attr, 0, sizeof(attr));
406
407         attr.mode = mode;
408         attr.ino = FUSE_ROOT_ID;
409         return fuse_iget(sb, 1, 0, &attr);
410 }
411
412 static struct super_operations fuse_super_operations = {
413         .alloc_inode    = fuse_alloc_inode,
414         .destroy_inode  = fuse_destroy_inode,
415         .read_inode     = fuse_read_inode,
416         .clear_inode    = fuse_clear_inode,
417         .put_super      = fuse_put_super,
418         .umount_begin   = fuse_umount_begin,
419         .statfs         = fuse_statfs,
420         .show_options   = fuse_show_options,
421 };
422
423 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
424 {
425         struct fuse_init_out *arg = &req->misc.init_out;
426
427         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
428                 fc->conn_error = 1;
429         else {
430                 unsigned long ra_pages;
431
432                 if (arg->minor >= 6) {
433                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
434                         if (arg->flags & FUSE_ASYNC_READ)
435                                 fc->async_read = 1;
436                 } else
437                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
438
439                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
440                 fc->minor = arg->minor;
441                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
442         }
443         fuse_put_request(fc, req);
444         fc->blocked = 0;
445         wake_up_all(&fc->blocked_waitq);
446 }
447
448 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
449 {
450         struct fuse_init_in *arg = &req->misc.init_in;
451
452         arg->major = FUSE_KERNEL_VERSION;
453         arg->minor = FUSE_KERNEL_MINOR_VERSION;
454         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
455         arg->flags |= FUSE_ASYNC_READ;
456         req->in.h.opcode = FUSE_INIT;
457         req->in.numargs = 1;
458         req->in.args[0].size = sizeof(*arg);
459         req->in.args[0].value = arg;
460         req->out.numargs = 1;
461         /* Variable length arguement used for backward compatibility
462            with interface version < 7.5.  Rest of init_out is zeroed
463            by do_get_request(), so a short reply is not a problem */
464         req->out.argvar = 1;
465         req->out.args[0].size = sizeof(struct fuse_init_out);
466         req->out.args[0].value = &req->misc.init_out;
467         req->end = process_init_reply;
468         request_send_background(fc, req);
469 }
470
471 static unsigned long long conn_id(void)
472 {
473         /* BKL is held for ->get_sb() */
474         static unsigned long long ctr = 1;
475         return ctr++;
476 }
477
478 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
479 {
480         struct fuse_conn *fc;
481         struct inode *root;
482         struct fuse_mount_data d;
483         struct file *file;
484         struct dentry *root_dentry;
485         struct fuse_req *init_req;
486         int err;
487
488         if (!parse_fuse_opt((char *) data, &d))
489                 return -EINVAL;
490
491         sb->s_blocksize = PAGE_CACHE_SIZE;
492         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
493         sb->s_magic = FUSE_SUPER_MAGIC;
494         sb->s_op = &fuse_super_operations;
495         sb->s_maxbytes = MAX_LFS_FILESIZE;
496
497         file = fget(d.fd);
498         if (!file)
499                 return -EINVAL;
500
501         if (file->f_op != &fuse_dev_operations)
502                 return -EINVAL;
503
504         fc = new_conn();
505         if (!fc)
506                 return -ENOMEM;
507
508         fc->flags = d.flags;
509         fc->user_id = d.user_id;
510         fc->group_id = d.group_id;
511         fc->max_read = d.max_read;
512
513         /* Used by get_root_inode() */
514         sb->s_fs_info = fc;
515
516         err = -ENOMEM;
517         root = get_root_inode(sb, d.rootmode);
518         if (!root)
519                 goto err;
520
521         root_dentry = d_alloc_root(root);
522         if (!root_dentry) {
523                 iput(root);
524                 goto err;
525         }
526
527         init_req = fuse_request_alloc();
528         if (!init_req)
529                 goto err_put_root;
530
531         err = kobject_set_name(&fc->kobj, "%llu", conn_id());
532         if (err)
533                 goto err_free_req;
534
535         err = kobject_add(&fc->kobj);
536         if (err)
537                 goto err_free_req;
538
539         /* Setting file->private_data can't race with other mount()
540            instances, since BKL is held for ->get_sb() */
541         err = -EINVAL;
542         if (file->private_data)
543                 goto err_kobject_del;
544
545         sb->s_root = root_dentry;
546         fc->mounted = 1;
547         fc->connected = 1;
548         kobject_get(&fc->kobj);
549         file->private_data = fc;
550         /*
551          * atomic_dec_and_test() in fput() provides the necessary
552          * memory barrier for file->private_data to be visible on all
553          * CPUs after this
554          */
555         fput(file);
556
557         fuse_send_init(fc, init_req);
558
559         return 0;
560
561  err_kobject_del:
562         kobject_del(&fc->kobj);
563  err_free_req:
564         fuse_request_free(init_req);
565  err_put_root:
566         dput(root_dentry);
567  err:
568         fput(file);
569         kobject_put(&fc->kobj);
570         return err;
571 }
572
573 static int fuse_get_sb(struct file_system_type *fs_type,
574                        int flags, const char *dev_name,
575                        void *raw_data, struct vfsmount *mnt)
576 {
577         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
578 }
579
580 static struct file_system_type fuse_fs_type = {
581         .owner          = THIS_MODULE,
582         .name           = "fuse",
583         .get_sb         = fuse_get_sb,
584         .kill_sb        = kill_anon_super,
585 };
586
587 static ssize_t fuse_conn_waiting_show(struct fuse_conn *fc, char *page)
588 {
589         return sprintf(page, "%i\n", atomic_read(&fc->num_waiting));
590 }
591
592 static ssize_t fuse_conn_abort_store(struct fuse_conn *fc, const char *page,
593                                      size_t count)
594 {
595         fuse_abort_conn(fc);
596         return count;
597 }
598
599 static struct fuse_conn_attr fuse_conn_waiting =
600         __ATTR(waiting, 0400, fuse_conn_waiting_show, NULL);
601 static struct fuse_conn_attr fuse_conn_abort =
602         __ATTR(abort, 0600, NULL, fuse_conn_abort_store);
603
604 static struct attribute *fuse_conn_attrs[] = {
605         &fuse_conn_waiting.attr,
606         &fuse_conn_abort.attr,
607         NULL,
608 };
609
610 static ssize_t fuse_conn_attr_show(struct kobject *kobj,
611                                    struct attribute *attr,
612                                    char *page)
613 {
614         struct fuse_conn_attr *fca =
615                 container_of(attr, struct fuse_conn_attr, attr);
616
617         if (fca->show)
618                 return fca->show(get_fuse_conn_kobj(kobj), page);
619         else
620                 return -EACCES;
621 }
622
623 static ssize_t fuse_conn_attr_store(struct kobject *kobj,
624                                     struct attribute *attr,
625                                     const char *page, size_t count)
626 {
627         struct fuse_conn_attr *fca =
628                 container_of(attr, struct fuse_conn_attr, attr);
629
630         if (fca->store)
631                 return fca->store(get_fuse_conn_kobj(kobj), page, count);
632         else
633                 return -EACCES;
634 }
635
636 static struct sysfs_ops fuse_conn_sysfs_ops = {
637         .show   = &fuse_conn_attr_show,
638         .store  = &fuse_conn_attr_store,
639 };
640
641 static struct kobj_type ktype_fuse_conn = {
642         .release        = fuse_conn_release,
643         .sysfs_ops      = &fuse_conn_sysfs_ops,
644         .default_attrs  = fuse_conn_attrs,
645 };
646
647 static decl_subsys(fuse, NULL, NULL);
648 static decl_subsys(connections, &ktype_fuse_conn, NULL);
649
650 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
651                                  unsigned long flags)
652 {
653         struct inode * inode = foo;
654
655         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
656             SLAB_CTOR_CONSTRUCTOR)
657                 inode_init_once(inode);
658 }
659
660 static int __init fuse_fs_init(void)
661 {
662         int err;
663
664         err = register_filesystem(&fuse_fs_type);
665         if (err)
666                 printk("fuse: failed to register filesystem\n");
667         else {
668                 fuse_inode_cachep = kmem_cache_create("fuse_inode",
669                                                       sizeof(struct fuse_inode),
670                                                       0, SLAB_HWCACHE_ALIGN,
671                                                       fuse_inode_init_once, NULL);
672                 if (!fuse_inode_cachep) {
673                         unregister_filesystem(&fuse_fs_type);
674                         err = -ENOMEM;
675                 }
676         }
677
678         return err;
679 }
680
681 static void fuse_fs_cleanup(void)
682 {
683         unregister_filesystem(&fuse_fs_type);
684         kmem_cache_destroy(fuse_inode_cachep);
685 }
686
687 static int fuse_sysfs_init(void)
688 {
689         int err;
690
691         kset_set_kset_s(&fuse_subsys, fs_subsys);
692         err = subsystem_register(&fuse_subsys);
693         if (err)
694                 goto out_err;
695
696         kset_set_kset_s(&connections_subsys, fuse_subsys);
697         err = subsystem_register(&connections_subsys);
698         if (err)
699                 goto out_fuse_unregister;
700
701         return 0;
702
703  out_fuse_unregister:
704         subsystem_unregister(&fuse_subsys);
705  out_err:
706         return err;
707 }
708
709 static void fuse_sysfs_cleanup(void)
710 {
711         subsystem_unregister(&connections_subsys);
712         subsystem_unregister(&fuse_subsys);
713 }
714
715 static int __init fuse_init(void)
716 {
717         int res;
718
719         printk("fuse init (API version %i.%i)\n",
720                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
721
722         res = fuse_fs_init();
723         if (res)
724                 goto err;
725
726         res = fuse_dev_init();
727         if (res)
728                 goto err_fs_cleanup;
729
730         res = fuse_sysfs_init();
731         if (res)
732                 goto err_dev_cleanup;
733
734         return 0;
735
736  err_dev_cleanup:
737         fuse_dev_cleanup();
738  err_fs_cleanup:
739         fuse_fs_cleanup();
740  err:
741         return res;
742 }
743
744 static void __exit fuse_exit(void)
745 {
746         printk(KERN_DEBUG "fuse exit\n");
747
748         fuse_sysfs_cleanup();
749         fuse_fs_cleanup();
750         fuse_dev_cleanup();
751 }
752
753 module_init(fuse_init);
754 module_exit(fuse_exit);