Merge tag 'modules-for-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu...
[sfrench/cifs-2.6.git] / fs / fuse / inode.c
1 /*
2   FUSE: Filesystem in Userspace
3   Copyright (C) 2001-2008  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/seq_file.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/parser.h>
19 #include <linux/statfs.h>
20 #include <linux/random.h>
21 #include <linux/sched.h>
22 #include <linux/exportfs.h>
23 #include <linux/posix_acl.h>
24 #include <linux/pid_namespace.h>
25
26 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
27 MODULE_DESCRIPTION("Filesystem in Userspace");
28 MODULE_LICENSE("GPL");
29
30 static struct kmem_cache *fuse_inode_cachep;
31 struct list_head fuse_conn_list;
32 DEFINE_MUTEX(fuse_mutex);
33
34 static int set_global_limit(const char *val, const struct kernel_param *kp);
35
36 unsigned max_user_bgreq;
37 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
38                   &max_user_bgreq, 0644);
39 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
40 MODULE_PARM_DESC(max_user_bgreq,
41  "Global limit for the maximum number of backgrounded requests an "
42  "unprivileged user can set");
43
44 unsigned max_user_congthresh;
45 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
46                   &max_user_congthresh, 0644);
47 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
48 MODULE_PARM_DESC(max_user_congthresh,
49  "Global limit for the maximum congestion threshold an "
50  "unprivileged user can set");
51
52 #define FUSE_SUPER_MAGIC 0x65735546
53
54 #define FUSE_DEFAULT_BLKSIZE 512
55
56 /** Maximum number of outstanding background requests */
57 #define FUSE_DEFAULT_MAX_BACKGROUND 12
58
59 /** Congestion starts at 75% of maximum */
60 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
61
62 struct fuse_mount_data {
63         int fd;
64         unsigned rootmode;
65         kuid_t user_id;
66         kgid_t group_id;
67         unsigned fd_present:1;
68         unsigned rootmode_present:1;
69         unsigned user_id_present:1;
70         unsigned group_id_present:1;
71         unsigned default_permissions:1;
72         unsigned allow_other:1;
73         unsigned max_read;
74         unsigned blksize;
75 };
76
77 struct fuse_forget_link *fuse_alloc_forget(void)
78 {
79         return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
80 }
81
82 static struct inode *fuse_alloc_inode(struct super_block *sb)
83 {
84         struct inode *inode;
85         struct fuse_inode *fi;
86
87         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
88         if (!inode)
89                 return NULL;
90
91         fi = get_fuse_inode(inode);
92         fi->i_time = 0;
93         fi->nodeid = 0;
94         fi->nlookup = 0;
95         fi->attr_version = 0;
96         fi->writectr = 0;
97         fi->orig_ino = 0;
98         fi->state = 0;
99         INIT_LIST_HEAD(&fi->write_files);
100         INIT_LIST_HEAD(&fi->queued_writes);
101         INIT_LIST_HEAD(&fi->writepages);
102         init_waitqueue_head(&fi->page_waitq);
103         mutex_init(&fi->mutex);
104         fi->forget = fuse_alloc_forget();
105         if (!fi->forget) {
106                 kmem_cache_free(fuse_inode_cachep, inode);
107                 return NULL;
108         }
109
110         return inode;
111 }
112
113 static void fuse_i_callback(struct rcu_head *head)
114 {
115         struct inode *inode = container_of(head, struct inode, i_rcu);
116         kmem_cache_free(fuse_inode_cachep, inode);
117 }
118
119 static void fuse_destroy_inode(struct inode *inode)
120 {
121         struct fuse_inode *fi = get_fuse_inode(inode);
122         BUG_ON(!list_empty(&fi->write_files));
123         BUG_ON(!list_empty(&fi->queued_writes));
124         mutex_destroy(&fi->mutex);
125         kfree(fi->forget);
126         call_rcu(&inode->i_rcu, fuse_i_callback);
127 }
128
129 static void fuse_evict_inode(struct inode *inode)
130 {
131         truncate_inode_pages_final(&inode->i_data);
132         clear_inode(inode);
133         if (inode->i_sb->s_flags & MS_ACTIVE) {
134                 struct fuse_conn *fc = get_fuse_conn(inode);
135                 struct fuse_inode *fi = get_fuse_inode(inode);
136                 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
137                 fi->forget = NULL;
138         }
139 }
140
141 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
142 {
143         sync_filesystem(sb);
144         if (*flags & MS_MANDLOCK)
145                 return -EINVAL;
146
147         return 0;
148 }
149
150 /*
151  * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
152  * so that it will fit.
153  */
154 static ino_t fuse_squash_ino(u64 ino64)
155 {
156         ino_t ino = (ino_t) ino64;
157         if (sizeof(ino_t) < sizeof(u64))
158                 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
159         return ino;
160 }
161
162 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
163                                    u64 attr_valid)
164 {
165         struct fuse_conn *fc = get_fuse_conn(inode);
166         struct fuse_inode *fi = get_fuse_inode(inode);
167
168         fi->attr_version = ++fc->attr_version;
169         fi->i_time = attr_valid;
170
171         inode->i_ino     = fuse_squash_ino(attr->ino);
172         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
173         set_nlink(inode, attr->nlink);
174         inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
175         inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
176         inode->i_blocks  = attr->blocks;
177         inode->i_atime.tv_sec   = attr->atime;
178         inode->i_atime.tv_nsec  = attr->atimensec;
179         /* mtime from server may be stale due to local buffered write */
180         if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
181                 inode->i_mtime.tv_sec   = attr->mtime;
182                 inode->i_mtime.tv_nsec  = attr->mtimensec;
183                 inode->i_ctime.tv_sec   = attr->ctime;
184                 inode->i_ctime.tv_nsec  = attr->ctimensec;
185         }
186
187         if (attr->blksize != 0)
188                 inode->i_blkbits = ilog2(attr->blksize);
189         else
190                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
191
192         /*
193          * Don't set the sticky bit in i_mode, unless we want the VFS
194          * to check permissions.  This prevents failures due to the
195          * check in may_delete().
196          */
197         fi->orig_i_mode = inode->i_mode;
198         if (!fc->default_permissions)
199                 inode->i_mode &= ~S_ISVTX;
200
201         fi->orig_ino = attr->ino;
202 }
203
204 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
205                             u64 attr_valid, u64 attr_version)
206 {
207         struct fuse_conn *fc = get_fuse_conn(inode);
208         struct fuse_inode *fi = get_fuse_inode(inode);
209         bool is_wb = fc->writeback_cache;
210         loff_t oldsize;
211         struct timespec old_mtime;
212
213         spin_lock(&fc->lock);
214         if ((attr_version != 0 && fi->attr_version > attr_version) ||
215             test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
216                 spin_unlock(&fc->lock);
217                 return;
218         }
219
220         old_mtime = inode->i_mtime;
221         fuse_change_attributes_common(inode, attr, attr_valid);
222
223         oldsize = inode->i_size;
224         /*
225          * In case of writeback_cache enabled, the cached writes beyond EOF
226          * extend local i_size without keeping userspace server in sync. So,
227          * attr->size coming from server can be stale. We cannot trust it.
228          */
229         if (!is_wb || !S_ISREG(inode->i_mode))
230                 i_size_write(inode, attr->size);
231         spin_unlock(&fc->lock);
232
233         if (!is_wb && S_ISREG(inode->i_mode)) {
234                 bool inval = false;
235
236                 if (oldsize != attr->size) {
237                         truncate_pagecache(inode, attr->size);
238                         inval = true;
239                 } else if (fc->auto_inval_data) {
240                         struct timespec new_mtime = {
241                                 .tv_sec = attr->mtime,
242                                 .tv_nsec = attr->mtimensec,
243                         };
244
245                         /*
246                          * Auto inval mode also checks and invalidates if mtime
247                          * has changed.
248                          */
249                         if (!timespec_equal(&old_mtime, &new_mtime))
250                                 inval = true;
251                 }
252
253                 if (inval)
254                         invalidate_inode_pages2(inode->i_mapping);
255         }
256 }
257
258 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
259 {
260         inode->i_mode = attr->mode & S_IFMT;
261         inode->i_size = attr->size;
262         inode->i_mtime.tv_sec  = attr->mtime;
263         inode->i_mtime.tv_nsec = attr->mtimensec;
264         inode->i_ctime.tv_sec  = attr->ctime;
265         inode->i_ctime.tv_nsec = attr->ctimensec;
266         if (S_ISREG(inode->i_mode)) {
267                 fuse_init_common(inode);
268                 fuse_init_file_inode(inode);
269         } else if (S_ISDIR(inode->i_mode))
270                 fuse_init_dir(inode);
271         else if (S_ISLNK(inode->i_mode))
272                 fuse_init_symlink(inode);
273         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
274                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
275                 fuse_init_common(inode);
276                 init_special_inode(inode, inode->i_mode,
277                                    new_decode_dev(attr->rdev));
278         } else
279                 BUG();
280 }
281
282 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
283 {
284         u64 nodeid = *(u64 *) _nodeidp;
285         if (get_node_id(inode) == nodeid)
286                 return 1;
287         else
288                 return 0;
289 }
290
291 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
292 {
293         u64 nodeid = *(u64 *) _nodeidp;
294         get_fuse_inode(inode)->nodeid = nodeid;
295         return 0;
296 }
297
298 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
299                         int generation, struct fuse_attr *attr,
300                         u64 attr_valid, u64 attr_version)
301 {
302         struct inode *inode;
303         struct fuse_inode *fi;
304         struct fuse_conn *fc = get_fuse_conn_super(sb);
305
306  retry:
307         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
308         if (!inode)
309                 return NULL;
310
311         if ((inode->i_state & I_NEW)) {
312                 inode->i_flags |= S_NOATIME;
313                 if (!fc->writeback_cache || !S_ISREG(attr->mode))
314                         inode->i_flags |= S_NOCMTIME;
315                 inode->i_generation = generation;
316                 fuse_init_inode(inode, attr);
317                 unlock_new_inode(inode);
318         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
319                 /* Inode has changed type, any I/O on the old should fail */
320                 make_bad_inode(inode);
321                 iput(inode);
322                 goto retry;
323         }
324
325         fi = get_fuse_inode(inode);
326         spin_lock(&fc->lock);
327         fi->nlookup++;
328         spin_unlock(&fc->lock);
329         fuse_change_attributes(inode, attr, attr_valid, attr_version);
330
331         return inode;
332 }
333
334 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
335                              loff_t offset, loff_t len)
336 {
337         struct inode *inode;
338         pgoff_t pg_start;
339         pgoff_t pg_end;
340
341         inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
342         if (!inode)
343                 return -ENOENT;
344
345         fuse_invalidate_attr(inode);
346         forget_all_cached_acls(inode);
347         if (offset >= 0) {
348                 pg_start = offset >> PAGE_SHIFT;
349                 if (len <= 0)
350                         pg_end = -1;
351                 else
352                         pg_end = (offset + len - 1) >> PAGE_SHIFT;
353                 invalidate_inode_pages2_range(inode->i_mapping,
354                                               pg_start, pg_end);
355         }
356         iput(inode);
357         return 0;
358 }
359
360 void fuse_lock_inode(struct inode *inode)
361 {
362         if (!get_fuse_conn(inode)->parallel_dirops)
363                 mutex_lock(&get_fuse_inode(inode)->mutex);
364 }
365
366 void fuse_unlock_inode(struct inode *inode)
367 {
368         if (!get_fuse_conn(inode)->parallel_dirops)
369                 mutex_unlock(&get_fuse_inode(inode)->mutex);
370 }
371
372 static void fuse_umount_begin(struct super_block *sb)
373 {
374         fuse_abort_conn(get_fuse_conn_super(sb));
375 }
376
377 static void fuse_send_destroy(struct fuse_conn *fc)
378 {
379         struct fuse_req *req = fc->destroy_req;
380         if (req && fc->conn_init) {
381                 fc->destroy_req = NULL;
382                 req->in.h.opcode = FUSE_DESTROY;
383                 __set_bit(FR_FORCE, &req->flags);
384                 __clear_bit(FR_BACKGROUND, &req->flags);
385                 fuse_request_send(fc, req);
386                 fuse_put_request(fc, req);
387         }
388 }
389
390 static void fuse_put_super(struct super_block *sb)
391 {
392         struct fuse_conn *fc = get_fuse_conn_super(sb);
393
394         fuse_send_destroy(fc);
395
396         fuse_abort_conn(fc);
397         mutex_lock(&fuse_mutex);
398         list_del(&fc->entry);
399         fuse_ctl_remove_conn(fc);
400         mutex_unlock(&fuse_mutex);
401
402         fuse_conn_put(fc);
403 }
404
405 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
406 {
407         stbuf->f_type    = FUSE_SUPER_MAGIC;
408         stbuf->f_bsize   = attr->bsize;
409         stbuf->f_frsize  = attr->frsize;
410         stbuf->f_blocks  = attr->blocks;
411         stbuf->f_bfree   = attr->bfree;
412         stbuf->f_bavail  = attr->bavail;
413         stbuf->f_files   = attr->files;
414         stbuf->f_ffree   = attr->ffree;
415         stbuf->f_namelen = attr->namelen;
416         /* fsid is left zero */
417 }
418
419 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
420 {
421         struct super_block *sb = dentry->d_sb;
422         struct fuse_conn *fc = get_fuse_conn_super(sb);
423         FUSE_ARGS(args);
424         struct fuse_statfs_out outarg;
425         int err;
426
427         if (!fuse_allow_current_process(fc)) {
428                 buf->f_type = FUSE_SUPER_MAGIC;
429                 return 0;
430         }
431
432         memset(&outarg, 0, sizeof(outarg));
433         args.in.numargs = 0;
434         args.in.h.opcode = FUSE_STATFS;
435         args.in.h.nodeid = get_node_id(d_inode(dentry));
436         args.out.numargs = 1;
437         args.out.args[0].size = sizeof(outarg);
438         args.out.args[0].value = &outarg;
439         err = fuse_simple_request(fc, &args);
440         if (!err)
441                 convert_fuse_statfs(buf, &outarg.st);
442         return err;
443 }
444
445 enum {
446         OPT_FD,
447         OPT_ROOTMODE,
448         OPT_USER_ID,
449         OPT_GROUP_ID,
450         OPT_DEFAULT_PERMISSIONS,
451         OPT_ALLOW_OTHER,
452         OPT_MAX_READ,
453         OPT_BLKSIZE,
454         OPT_ERR
455 };
456
457 static const match_table_t tokens = {
458         {OPT_FD,                        "fd=%u"},
459         {OPT_ROOTMODE,                  "rootmode=%o"},
460         {OPT_USER_ID,                   "user_id=%u"},
461         {OPT_GROUP_ID,                  "group_id=%u"},
462         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
463         {OPT_ALLOW_OTHER,               "allow_other"},
464         {OPT_MAX_READ,                  "max_read=%u"},
465         {OPT_BLKSIZE,                   "blksize=%u"},
466         {OPT_ERR,                       NULL}
467 };
468
469 static int fuse_match_uint(substring_t *s, unsigned int *res)
470 {
471         int err = -ENOMEM;
472         char *buf = match_strdup(s);
473         if (buf) {
474                 err = kstrtouint(buf, 10, res);
475                 kfree(buf);
476         }
477         return err;
478 }
479
480 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
481 {
482         char *p;
483         memset(d, 0, sizeof(struct fuse_mount_data));
484         d->max_read = ~0;
485         d->blksize = FUSE_DEFAULT_BLKSIZE;
486
487         while ((p = strsep(&opt, ",")) != NULL) {
488                 int token;
489                 int value;
490                 unsigned uv;
491                 substring_t args[MAX_OPT_ARGS];
492                 if (!*p)
493                         continue;
494
495                 token = match_token(p, tokens, args);
496                 switch (token) {
497                 case OPT_FD:
498                         if (match_int(&args[0], &value))
499                                 return 0;
500                         d->fd = value;
501                         d->fd_present = 1;
502                         break;
503
504                 case OPT_ROOTMODE:
505                         if (match_octal(&args[0], &value))
506                                 return 0;
507                         if (!fuse_valid_type(value))
508                                 return 0;
509                         d->rootmode = value;
510                         d->rootmode_present = 1;
511                         break;
512
513                 case OPT_USER_ID:
514                         if (fuse_match_uint(&args[0], &uv))
515                                 return 0;
516                         d->user_id = make_kuid(current_user_ns(), uv);
517                         if (!uid_valid(d->user_id))
518                                 return 0;
519                         d->user_id_present = 1;
520                         break;
521
522                 case OPT_GROUP_ID:
523                         if (fuse_match_uint(&args[0], &uv))
524                                 return 0;
525                         d->group_id = make_kgid(current_user_ns(), uv);
526                         if (!gid_valid(d->group_id))
527                                 return 0;
528                         d->group_id_present = 1;
529                         break;
530
531                 case OPT_DEFAULT_PERMISSIONS:
532                         d->default_permissions = 1;
533                         break;
534
535                 case OPT_ALLOW_OTHER:
536                         d->allow_other = 1;
537                         break;
538
539                 case OPT_MAX_READ:
540                         if (match_int(&args[0], &value))
541                                 return 0;
542                         d->max_read = value;
543                         break;
544
545                 case OPT_BLKSIZE:
546                         if (!is_bdev || match_int(&args[0], &value))
547                                 return 0;
548                         d->blksize = value;
549                         break;
550
551                 default:
552                         return 0;
553                 }
554         }
555
556         if (!d->fd_present || !d->rootmode_present ||
557             !d->user_id_present || !d->group_id_present)
558                 return 0;
559
560         return 1;
561 }
562
563 static int fuse_show_options(struct seq_file *m, struct dentry *root)
564 {
565         struct super_block *sb = root->d_sb;
566         struct fuse_conn *fc = get_fuse_conn_super(sb);
567
568         seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
569         seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
570         if (fc->default_permissions)
571                 seq_puts(m, ",default_permissions");
572         if (fc->allow_other)
573                 seq_puts(m, ",allow_other");
574         if (fc->max_read != ~0)
575                 seq_printf(m, ",max_read=%u", fc->max_read);
576         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
577                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
578         return 0;
579 }
580
581 static void fuse_iqueue_init(struct fuse_iqueue *fiq)
582 {
583         memset(fiq, 0, sizeof(struct fuse_iqueue));
584         init_waitqueue_head(&fiq->waitq);
585         INIT_LIST_HEAD(&fiq->pending);
586         INIT_LIST_HEAD(&fiq->interrupts);
587         fiq->forget_list_tail = &fiq->forget_list_head;
588         fiq->connected = 1;
589 }
590
591 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
592 {
593         memset(fpq, 0, sizeof(struct fuse_pqueue));
594         spin_lock_init(&fpq->lock);
595         INIT_LIST_HEAD(&fpq->processing);
596         INIT_LIST_HEAD(&fpq->io);
597         fpq->connected = 1;
598 }
599
600 void fuse_conn_init(struct fuse_conn *fc)
601 {
602         memset(fc, 0, sizeof(*fc));
603         spin_lock_init(&fc->lock);
604         init_rwsem(&fc->killsb);
605         refcount_set(&fc->count, 1);
606         atomic_set(&fc->dev_count, 1);
607         init_waitqueue_head(&fc->blocked_waitq);
608         init_waitqueue_head(&fc->reserved_req_waitq);
609         fuse_iqueue_init(&fc->iq);
610         INIT_LIST_HEAD(&fc->bg_queue);
611         INIT_LIST_HEAD(&fc->entry);
612         INIT_LIST_HEAD(&fc->devices);
613         atomic_set(&fc->num_waiting, 0);
614         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
615         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
616         fc->khctr = 0;
617         fc->polled_files = RB_ROOT;
618         fc->blocked = 0;
619         fc->initialized = 0;
620         fc->connected = 1;
621         fc->attr_version = 1;
622         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
623         fc->pid_ns = get_pid_ns(task_active_pid_ns(current));
624 }
625 EXPORT_SYMBOL_GPL(fuse_conn_init);
626
627 void fuse_conn_put(struct fuse_conn *fc)
628 {
629         if (refcount_dec_and_test(&fc->count)) {
630                 if (fc->destroy_req)
631                         fuse_request_free(fc->destroy_req);
632                 put_pid_ns(fc->pid_ns);
633                 fc->release(fc);
634         }
635 }
636 EXPORT_SYMBOL_GPL(fuse_conn_put);
637
638 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
639 {
640         refcount_inc(&fc->count);
641         return fc;
642 }
643 EXPORT_SYMBOL_GPL(fuse_conn_get);
644
645 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
646 {
647         struct fuse_attr attr;
648         memset(&attr, 0, sizeof(attr));
649
650         attr.mode = mode;
651         attr.ino = FUSE_ROOT_ID;
652         attr.nlink = 1;
653         return fuse_iget(sb, 1, 0, &attr, 0, 0);
654 }
655
656 struct fuse_inode_handle {
657         u64 nodeid;
658         u32 generation;
659 };
660
661 static struct dentry *fuse_get_dentry(struct super_block *sb,
662                                       struct fuse_inode_handle *handle)
663 {
664         struct fuse_conn *fc = get_fuse_conn_super(sb);
665         struct inode *inode;
666         struct dentry *entry;
667         int err = -ESTALE;
668
669         if (handle->nodeid == 0)
670                 goto out_err;
671
672         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
673         if (!inode) {
674                 struct fuse_entry_out outarg;
675                 const struct qstr name = QSTR_INIT(".", 1);
676
677                 if (!fc->export_support)
678                         goto out_err;
679
680                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
681                                        &inode);
682                 if (err && err != -ENOENT)
683                         goto out_err;
684                 if (err || !inode) {
685                         err = -ESTALE;
686                         goto out_err;
687                 }
688                 err = -EIO;
689                 if (get_node_id(inode) != handle->nodeid)
690                         goto out_iput;
691         }
692         err = -ESTALE;
693         if (inode->i_generation != handle->generation)
694                 goto out_iput;
695
696         entry = d_obtain_alias(inode);
697         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
698                 fuse_invalidate_entry_cache(entry);
699
700         return entry;
701
702  out_iput:
703         iput(inode);
704  out_err:
705         return ERR_PTR(err);
706 }
707
708 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
709                            struct inode *parent)
710 {
711         int len = parent ? 6 : 3;
712         u64 nodeid;
713         u32 generation;
714
715         if (*max_len < len) {
716                 *max_len = len;
717                 return  FILEID_INVALID;
718         }
719
720         nodeid = get_fuse_inode(inode)->nodeid;
721         generation = inode->i_generation;
722
723         fh[0] = (u32)(nodeid >> 32);
724         fh[1] = (u32)(nodeid & 0xffffffff);
725         fh[2] = generation;
726
727         if (parent) {
728                 nodeid = get_fuse_inode(parent)->nodeid;
729                 generation = parent->i_generation;
730
731                 fh[3] = (u32)(nodeid >> 32);
732                 fh[4] = (u32)(nodeid & 0xffffffff);
733                 fh[5] = generation;
734         }
735
736         *max_len = len;
737         return parent ? 0x82 : 0x81;
738 }
739
740 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
741                 struct fid *fid, int fh_len, int fh_type)
742 {
743         struct fuse_inode_handle handle;
744
745         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
746                 return NULL;
747
748         handle.nodeid = (u64) fid->raw[0] << 32;
749         handle.nodeid |= (u64) fid->raw[1];
750         handle.generation = fid->raw[2];
751         return fuse_get_dentry(sb, &handle);
752 }
753
754 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
755                 struct fid *fid, int fh_len, int fh_type)
756 {
757         struct fuse_inode_handle parent;
758
759         if (fh_type != 0x82 || fh_len < 6)
760                 return NULL;
761
762         parent.nodeid = (u64) fid->raw[3] << 32;
763         parent.nodeid |= (u64) fid->raw[4];
764         parent.generation = fid->raw[5];
765         return fuse_get_dentry(sb, &parent);
766 }
767
768 static struct dentry *fuse_get_parent(struct dentry *child)
769 {
770         struct inode *child_inode = d_inode(child);
771         struct fuse_conn *fc = get_fuse_conn(child_inode);
772         struct inode *inode;
773         struct dentry *parent;
774         struct fuse_entry_out outarg;
775         const struct qstr name = QSTR_INIT("..", 2);
776         int err;
777
778         if (!fc->export_support)
779                 return ERR_PTR(-ESTALE);
780
781         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
782                                &name, &outarg, &inode);
783         if (err) {
784                 if (err == -ENOENT)
785                         return ERR_PTR(-ESTALE);
786                 return ERR_PTR(err);
787         }
788
789         parent = d_obtain_alias(inode);
790         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
791                 fuse_invalidate_entry_cache(parent);
792
793         return parent;
794 }
795
796 static const struct export_operations fuse_export_operations = {
797         .fh_to_dentry   = fuse_fh_to_dentry,
798         .fh_to_parent   = fuse_fh_to_parent,
799         .encode_fh      = fuse_encode_fh,
800         .get_parent     = fuse_get_parent,
801 };
802
803 static const struct super_operations fuse_super_operations = {
804         .alloc_inode    = fuse_alloc_inode,
805         .destroy_inode  = fuse_destroy_inode,
806         .evict_inode    = fuse_evict_inode,
807         .write_inode    = fuse_write_inode,
808         .drop_inode     = generic_delete_inode,
809         .remount_fs     = fuse_remount_fs,
810         .put_super      = fuse_put_super,
811         .umount_begin   = fuse_umount_begin,
812         .statfs         = fuse_statfs,
813         .show_options   = fuse_show_options,
814 };
815
816 static void sanitize_global_limit(unsigned *limit)
817 {
818         if (*limit == 0)
819                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
820                          sizeof(struct fuse_req);
821
822         if (*limit >= 1 << 16)
823                 *limit = (1 << 16) - 1;
824 }
825
826 static int set_global_limit(const char *val, const struct kernel_param *kp)
827 {
828         int rv;
829
830         rv = param_set_uint(val, kp);
831         if (rv)
832                 return rv;
833
834         sanitize_global_limit((unsigned *)kp->arg);
835
836         return 0;
837 }
838
839 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
840 {
841         int cap_sys_admin = capable(CAP_SYS_ADMIN);
842
843         if (arg->minor < 13)
844                 return;
845
846         sanitize_global_limit(&max_user_bgreq);
847         sanitize_global_limit(&max_user_congthresh);
848
849         if (arg->max_background) {
850                 fc->max_background = arg->max_background;
851
852                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
853                         fc->max_background = max_user_bgreq;
854         }
855         if (arg->congestion_threshold) {
856                 fc->congestion_threshold = arg->congestion_threshold;
857
858                 if (!cap_sys_admin &&
859                     fc->congestion_threshold > max_user_congthresh)
860                         fc->congestion_threshold = max_user_congthresh;
861         }
862 }
863
864 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
865 {
866         struct fuse_init_out *arg = &req->misc.init_out;
867
868         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
869                 fc->conn_error = 1;
870         else {
871                 unsigned long ra_pages;
872
873                 process_init_limits(fc, arg);
874
875                 if (arg->minor >= 6) {
876                         ra_pages = arg->max_readahead / PAGE_SIZE;
877                         if (arg->flags & FUSE_ASYNC_READ)
878                                 fc->async_read = 1;
879                         if (!(arg->flags & FUSE_POSIX_LOCKS))
880                                 fc->no_lock = 1;
881                         if (arg->minor >= 17) {
882                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
883                                         fc->no_flock = 1;
884                         } else {
885                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
886                                         fc->no_flock = 1;
887                         }
888                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
889                                 fc->atomic_o_trunc = 1;
890                         if (arg->minor >= 9) {
891                                 /* LOOKUP has dependency on proto version */
892                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
893                                         fc->export_support = 1;
894                         }
895                         if (arg->flags & FUSE_BIG_WRITES)
896                                 fc->big_writes = 1;
897                         if (arg->flags & FUSE_DONT_MASK)
898                                 fc->dont_mask = 1;
899                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
900                                 fc->auto_inval_data = 1;
901                         if (arg->flags & FUSE_DO_READDIRPLUS) {
902                                 fc->do_readdirplus = 1;
903                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
904                                         fc->readdirplus_auto = 1;
905                         }
906                         if (arg->flags & FUSE_ASYNC_DIO)
907                                 fc->async_dio = 1;
908                         if (arg->flags & FUSE_WRITEBACK_CACHE)
909                                 fc->writeback_cache = 1;
910                         if (arg->flags & FUSE_PARALLEL_DIROPS)
911                                 fc->parallel_dirops = 1;
912                         if (arg->flags & FUSE_HANDLE_KILLPRIV)
913                                 fc->handle_killpriv = 1;
914                         if (arg->time_gran && arg->time_gran <= 1000000000)
915                                 fc->sb->s_time_gran = arg->time_gran;
916                         if ((arg->flags & FUSE_POSIX_ACL)) {
917                                 fc->default_permissions = 1;
918                                 fc->posix_acl = 1;
919                                 fc->sb->s_xattr = fuse_acl_xattr_handlers;
920                         }
921                 } else {
922                         ra_pages = fc->max_read / PAGE_SIZE;
923                         fc->no_lock = 1;
924                         fc->no_flock = 1;
925                 }
926
927                 fc->sb->s_bdi->ra_pages =
928                                 min(fc->sb->s_bdi->ra_pages, ra_pages);
929                 fc->minor = arg->minor;
930                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
931                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
932                 fc->conn_init = 1;
933         }
934         fuse_set_initialized(fc);
935         wake_up_all(&fc->blocked_waitq);
936 }
937
938 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
939 {
940         struct fuse_init_in *arg = &req->misc.init_in;
941
942         arg->major = FUSE_KERNEL_VERSION;
943         arg->minor = FUSE_KERNEL_MINOR_VERSION;
944         arg->max_readahead = fc->sb->s_bdi->ra_pages * PAGE_SIZE;
945         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
946                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
947                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
948                 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
949                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
950                 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
951                 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL;
952         req->in.h.opcode = FUSE_INIT;
953         req->in.numargs = 1;
954         req->in.args[0].size = sizeof(*arg);
955         req->in.args[0].value = arg;
956         req->out.numargs = 1;
957         /* Variable length argument used for backward compatibility
958            with interface version < 7.5.  Rest of init_out is zeroed
959            by do_get_request(), so a short reply is not a problem */
960         req->out.argvar = 1;
961         req->out.args[0].size = sizeof(struct fuse_init_out);
962         req->out.args[0].value = &req->misc.init_out;
963         req->end = process_init_reply;
964         fuse_request_send_background(fc, req);
965 }
966
967 static void fuse_free_conn(struct fuse_conn *fc)
968 {
969         WARN_ON(!list_empty(&fc->devices));
970         kfree_rcu(fc, rcu);
971 }
972
973 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
974 {
975         int err;
976         char *suffix = "";
977
978         if (sb->s_bdev) {
979                 suffix = "-fuseblk";
980                 /*
981                  * sb->s_bdi points to blkdev's bdi however we want to redirect
982                  * it to our private bdi...
983                  */
984                 bdi_put(sb->s_bdi);
985                 sb->s_bdi = &noop_backing_dev_info;
986         }
987         err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
988                                    MINOR(fc->dev), suffix);
989         if (err)
990                 return err;
991
992         sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
993         /* fuse does it's own writeback accounting */
994         sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
995
996         /*
997          * For a single fuse filesystem use max 1% of dirty +
998          * writeback threshold.
999          *
1000          * This gives about 1M of write buffer for memory maps on a
1001          * machine with 1G and 10% dirty_ratio, which should be more
1002          * than enough.
1003          *
1004          * Privileged users can raise it by writing to
1005          *
1006          *    /sys/class/bdi/<bdi>/max_ratio
1007          */
1008         bdi_set_max_ratio(sb->s_bdi, 1);
1009
1010         return 0;
1011 }
1012
1013 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
1014 {
1015         struct fuse_dev *fud;
1016
1017         fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1018         if (fud) {
1019                 fud->fc = fuse_conn_get(fc);
1020                 fuse_pqueue_init(&fud->pq);
1021
1022                 spin_lock(&fc->lock);
1023                 list_add_tail(&fud->entry, &fc->devices);
1024                 spin_unlock(&fc->lock);
1025         }
1026
1027         return fud;
1028 }
1029 EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1030
1031 void fuse_dev_free(struct fuse_dev *fud)
1032 {
1033         struct fuse_conn *fc = fud->fc;
1034
1035         if (fc) {
1036                 spin_lock(&fc->lock);
1037                 list_del(&fud->entry);
1038                 spin_unlock(&fc->lock);
1039
1040                 fuse_conn_put(fc);
1041         }
1042         kfree(fud);
1043 }
1044 EXPORT_SYMBOL_GPL(fuse_dev_free);
1045
1046 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1047 {
1048         struct fuse_dev *fud;
1049         struct fuse_conn *fc;
1050         struct inode *root;
1051         struct fuse_mount_data d;
1052         struct file *file;
1053         struct dentry *root_dentry;
1054         struct fuse_req *init_req;
1055         int err;
1056         int is_bdev = sb->s_bdev != NULL;
1057
1058         err = -EINVAL;
1059         if (sb->s_flags & MS_MANDLOCK)
1060                 goto err;
1061
1062         sb->s_flags &= ~(MS_NOSEC | SB_I_VERSION);
1063
1064         if (!parse_fuse_opt(data, &d, is_bdev))
1065                 goto err;
1066
1067         if (is_bdev) {
1068 #ifdef CONFIG_BLOCK
1069                 err = -EINVAL;
1070                 if (!sb_set_blocksize(sb, d.blksize))
1071                         goto err;
1072 #endif
1073         } else {
1074                 sb->s_blocksize = PAGE_SIZE;
1075                 sb->s_blocksize_bits = PAGE_SHIFT;
1076         }
1077         sb->s_magic = FUSE_SUPER_MAGIC;
1078         sb->s_op = &fuse_super_operations;
1079         sb->s_xattr = fuse_xattr_handlers;
1080         sb->s_maxbytes = MAX_LFS_FILESIZE;
1081         sb->s_time_gran = 1;
1082         sb->s_export_op = &fuse_export_operations;
1083
1084         file = fget(d.fd);
1085         err = -EINVAL;
1086         if (!file)
1087                 goto err;
1088
1089         if ((file->f_op != &fuse_dev_operations) ||
1090             (file->f_cred->user_ns != &init_user_ns))
1091                 goto err_fput;
1092
1093         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1094         err = -ENOMEM;
1095         if (!fc)
1096                 goto err_fput;
1097
1098         fuse_conn_init(fc);
1099         fc->release = fuse_free_conn;
1100
1101         fud = fuse_dev_alloc(fc);
1102         if (!fud)
1103                 goto err_put_conn;
1104
1105         fc->dev = sb->s_dev;
1106         fc->sb = sb;
1107         err = fuse_bdi_init(fc, sb);
1108         if (err)
1109                 goto err_dev_free;
1110
1111         /* Handle umasking inside the fuse code */
1112         if (sb->s_flags & MS_POSIXACL)
1113                 fc->dont_mask = 1;
1114         sb->s_flags |= MS_POSIXACL;
1115
1116         fc->default_permissions = d.default_permissions;
1117         fc->allow_other = d.allow_other;
1118         fc->user_id = d.user_id;
1119         fc->group_id = d.group_id;
1120         fc->max_read = max_t(unsigned, 4096, d.max_read);
1121
1122         /* Used by get_root_inode() */
1123         sb->s_fs_info = fc;
1124
1125         err = -ENOMEM;
1126         root = fuse_get_root_inode(sb, d.rootmode);
1127         sb->s_d_op = &fuse_root_dentry_operations;
1128         root_dentry = d_make_root(root);
1129         if (!root_dentry)
1130                 goto err_dev_free;
1131         /* Root dentry doesn't have .d_revalidate */
1132         sb->s_d_op = &fuse_dentry_operations;
1133
1134         init_req = fuse_request_alloc(0);
1135         if (!init_req)
1136                 goto err_put_root;
1137         __set_bit(FR_BACKGROUND, &init_req->flags);
1138
1139         if (is_bdev) {
1140                 fc->destroy_req = fuse_request_alloc(0);
1141                 if (!fc->destroy_req)
1142                         goto err_free_init_req;
1143         }
1144
1145         mutex_lock(&fuse_mutex);
1146         err = -EINVAL;
1147         if (file->private_data)
1148                 goto err_unlock;
1149
1150         err = fuse_ctl_add_conn(fc);
1151         if (err)
1152                 goto err_unlock;
1153
1154         list_add_tail(&fc->entry, &fuse_conn_list);
1155         sb->s_root = root_dentry;
1156         file->private_data = fud;
1157         mutex_unlock(&fuse_mutex);
1158         /*
1159          * atomic_dec_and_test() in fput() provides the necessary
1160          * memory barrier for file->private_data to be visible on all
1161          * CPUs after this
1162          */
1163         fput(file);
1164
1165         fuse_send_init(fc, init_req);
1166
1167         return 0;
1168
1169  err_unlock:
1170         mutex_unlock(&fuse_mutex);
1171  err_free_init_req:
1172         fuse_request_free(init_req);
1173  err_put_root:
1174         dput(root_dentry);
1175  err_dev_free:
1176         fuse_dev_free(fud);
1177  err_put_conn:
1178         fuse_conn_put(fc);
1179  err_fput:
1180         fput(file);
1181  err:
1182         return err;
1183 }
1184
1185 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1186                        int flags, const char *dev_name,
1187                        void *raw_data)
1188 {
1189         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1190 }
1191
1192 static void fuse_kill_sb_anon(struct super_block *sb)
1193 {
1194         struct fuse_conn *fc = get_fuse_conn_super(sb);
1195
1196         if (fc) {
1197                 down_write(&fc->killsb);
1198                 fc->sb = NULL;
1199                 up_write(&fc->killsb);
1200         }
1201
1202         kill_anon_super(sb);
1203 }
1204
1205 static struct file_system_type fuse_fs_type = {
1206         .owner          = THIS_MODULE,
1207         .name           = "fuse",
1208         .fs_flags       = FS_HAS_SUBTYPE,
1209         .mount          = fuse_mount,
1210         .kill_sb        = fuse_kill_sb_anon,
1211 };
1212 MODULE_ALIAS_FS("fuse");
1213
1214 #ifdef CONFIG_BLOCK
1215 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1216                            int flags, const char *dev_name,
1217                            void *raw_data)
1218 {
1219         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1220 }
1221
1222 static void fuse_kill_sb_blk(struct super_block *sb)
1223 {
1224         struct fuse_conn *fc = get_fuse_conn_super(sb);
1225
1226         if (fc) {
1227                 down_write(&fc->killsb);
1228                 fc->sb = NULL;
1229                 up_write(&fc->killsb);
1230         }
1231
1232         kill_block_super(sb);
1233 }
1234
1235 static struct file_system_type fuseblk_fs_type = {
1236         .owner          = THIS_MODULE,
1237         .name           = "fuseblk",
1238         .mount          = fuse_mount_blk,
1239         .kill_sb        = fuse_kill_sb_blk,
1240         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1241 };
1242 MODULE_ALIAS_FS("fuseblk");
1243
1244 static inline int register_fuseblk(void)
1245 {
1246         return register_filesystem(&fuseblk_fs_type);
1247 }
1248
1249 static inline void unregister_fuseblk(void)
1250 {
1251         unregister_filesystem(&fuseblk_fs_type);
1252 }
1253 #else
1254 static inline int register_fuseblk(void)
1255 {
1256         return 0;
1257 }
1258
1259 static inline void unregister_fuseblk(void)
1260 {
1261 }
1262 #endif
1263
1264 static void fuse_inode_init_once(void *foo)
1265 {
1266         struct inode *inode = foo;
1267
1268         inode_init_once(inode);
1269 }
1270
1271 static int __init fuse_fs_init(void)
1272 {
1273         int err;
1274
1275         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1276                                               sizeof(struct fuse_inode), 0,
1277                                               SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
1278                                               fuse_inode_init_once);
1279         err = -ENOMEM;
1280         if (!fuse_inode_cachep)
1281                 goto out;
1282
1283         err = register_fuseblk();
1284         if (err)
1285                 goto out2;
1286
1287         err = register_filesystem(&fuse_fs_type);
1288         if (err)
1289                 goto out3;
1290
1291         return 0;
1292
1293  out3:
1294         unregister_fuseblk();
1295  out2:
1296         kmem_cache_destroy(fuse_inode_cachep);
1297  out:
1298         return err;
1299 }
1300
1301 static void fuse_fs_cleanup(void)
1302 {
1303         unregister_filesystem(&fuse_fs_type);
1304         unregister_fuseblk();
1305
1306         /*
1307          * Make sure all delayed rcu free inodes are flushed before we
1308          * destroy cache.
1309          */
1310         rcu_barrier();
1311         kmem_cache_destroy(fuse_inode_cachep);
1312 }
1313
1314 static struct kobject *fuse_kobj;
1315
1316 static int fuse_sysfs_init(void)
1317 {
1318         int err;
1319
1320         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1321         if (!fuse_kobj) {
1322                 err = -ENOMEM;
1323                 goto out_err;
1324         }
1325
1326         err = sysfs_create_mount_point(fuse_kobj, "connections");
1327         if (err)
1328                 goto out_fuse_unregister;
1329
1330         return 0;
1331
1332  out_fuse_unregister:
1333         kobject_put(fuse_kobj);
1334  out_err:
1335         return err;
1336 }
1337
1338 static void fuse_sysfs_cleanup(void)
1339 {
1340         sysfs_remove_mount_point(fuse_kobj, "connections");
1341         kobject_put(fuse_kobj);
1342 }
1343
1344 static int __init fuse_init(void)
1345 {
1346         int res;
1347
1348         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1349                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1350
1351         INIT_LIST_HEAD(&fuse_conn_list);
1352         res = fuse_fs_init();
1353         if (res)
1354                 goto err;
1355
1356         res = fuse_dev_init();
1357         if (res)
1358                 goto err_fs_cleanup;
1359
1360         res = fuse_sysfs_init();
1361         if (res)
1362                 goto err_dev_cleanup;
1363
1364         res = fuse_ctl_init();
1365         if (res)
1366                 goto err_sysfs_cleanup;
1367
1368         sanitize_global_limit(&max_user_bgreq);
1369         sanitize_global_limit(&max_user_congthresh);
1370
1371         return 0;
1372
1373  err_sysfs_cleanup:
1374         fuse_sysfs_cleanup();
1375  err_dev_cleanup:
1376         fuse_dev_cleanup();
1377  err_fs_cleanup:
1378         fuse_fs_cleanup();
1379  err:
1380         return res;
1381 }
1382
1383 static void __exit fuse_exit(void)
1384 {
1385         printk(KERN_DEBUG "fuse exit\n");
1386
1387         fuse_ctl_cleanup();
1388         fuse_sysfs_cleanup();
1389         fuse_fs_cleanup();
1390         fuse_dev_cleanup();
1391 }
1392
1393 module_init(fuse_init);
1394 module_exit(fuse_exit);