Merge tag 'fuse-update-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mszered...
[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 & SB_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 & SB_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(fc->user_ns, attr->uid);
175         inode->i_gid     = make_kgid(fc->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), false);
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, false);
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                           struct user_namespace *user_ns)
482 {
483         char *p;
484         memset(d, 0, sizeof(struct fuse_mount_data));
485         d->max_read = ~0;
486         d->blksize = FUSE_DEFAULT_BLKSIZE;
487
488         while ((p = strsep(&opt, ",")) != NULL) {
489                 int token;
490                 int value;
491                 unsigned uv;
492                 substring_t args[MAX_OPT_ARGS];
493                 if (!*p)
494                         continue;
495
496                 token = match_token(p, tokens, args);
497                 switch (token) {
498                 case OPT_FD:
499                         if (match_int(&args[0], &value))
500                                 return 0;
501                         d->fd = value;
502                         d->fd_present = 1;
503                         break;
504
505                 case OPT_ROOTMODE:
506                         if (match_octal(&args[0], &value))
507                                 return 0;
508                         if (!fuse_valid_type(value))
509                                 return 0;
510                         d->rootmode = value;
511                         d->rootmode_present = 1;
512                         break;
513
514                 case OPT_USER_ID:
515                         if (fuse_match_uint(&args[0], &uv))
516                                 return 0;
517                         d->user_id = make_kuid(user_ns, uv);
518                         if (!uid_valid(d->user_id))
519                                 return 0;
520                         d->user_id_present = 1;
521                         break;
522
523                 case OPT_GROUP_ID:
524                         if (fuse_match_uint(&args[0], &uv))
525                                 return 0;
526                         d->group_id = make_kgid(user_ns, uv);
527                         if (!gid_valid(d->group_id))
528                                 return 0;
529                         d->group_id_present = 1;
530                         break;
531
532                 case OPT_DEFAULT_PERMISSIONS:
533                         d->default_permissions = 1;
534                         break;
535
536                 case OPT_ALLOW_OTHER:
537                         d->allow_other = 1;
538                         break;
539
540                 case OPT_MAX_READ:
541                         if (match_int(&args[0], &value))
542                                 return 0;
543                         d->max_read = value;
544                         break;
545
546                 case OPT_BLKSIZE:
547                         if (!is_bdev || match_int(&args[0], &value))
548                                 return 0;
549                         d->blksize = value;
550                         break;
551
552                 default:
553                         return 0;
554                 }
555         }
556
557         if (!d->fd_present || !d->rootmode_present ||
558             !d->user_id_present || !d->group_id_present)
559                 return 0;
560
561         return 1;
562 }
563
564 static int fuse_show_options(struct seq_file *m, struct dentry *root)
565 {
566         struct super_block *sb = root->d_sb;
567         struct fuse_conn *fc = get_fuse_conn_super(sb);
568
569         seq_printf(m, ",user_id=%u", from_kuid_munged(fc->user_ns, fc->user_id));
570         seq_printf(m, ",group_id=%u", from_kgid_munged(fc->user_ns, fc->group_id));
571         if (fc->default_permissions)
572                 seq_puts(m, ",default_permissions");
573         if (fc->allow_other)
574                 seq_puts(m, ",allow_other");
575         if (fc->max_read != ~0)
576                 seq_printf(m, ",max_read=%u", fc->max_read);
577         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
578                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
579         return 0;
580 }
581
582 static void fuse_iqueue_init(struct fuse_iqueue *fiq)
583 {
584         memset(fiq, 0, sizeof(struct fuse_iqueue));
585         init_waitqueue_head(&fiq->waitq);
586         INIT_LIST_HEAD(&fiq->pending);
587         INIT_LIST_HEAD(&fiq->interrupts);
588         fiq->forget_list_tail = &fiq->forget_list_head;
589         fiq->connected = 1;
590 }
591
592 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
593 {
594         memset(fpq, 0, sizeof(struct fuse_pqueue));
595         spin_lock_init(&fpq->lock);
596         INIT_LIST_HEAD(&fpq->processing);
597         INIT_LIST_HEAD(&fpq->io);
598         fpq->connected = 1;
599 }
600
601 void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns)
602 {
603         memset(fc, 0, sizeof(*fc));
604         spin_lock_init(&fc->lock);
605         init_rwsem(&fc->killsb);
606         refcount_set(&fc->count, 1);
607         atomic_set(&fc->dev_count, 1);
608         init_waitqueue_head(&fc->blocked_waitq);
609         init_waitqueue_head(&fc->reserved_req_waitq);
610         fuse_iqueue_init(&fc->iq);
611         INIT_LIST_HEAD(&fc->bg_queue);
612         INIT_LIST_HEAD(&fc->entry);
613         INIT_LIST_HEAD(&fc->devices);
614         atomic_set(&fc->num_waiting, 0);
615         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
616         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
617         fc->khctr = 0;
618         fc->polled_files = RB_ROOT;
619         fc->blocked = 0;
620         fc->initialized = 0;
621         fc->connected = 1;
622         fc->attr_version = 1;
623         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
624         fc->pid_ns = get_pid_ns(task_active_pid_ns(current));
625         fc->user_ns = get_user_ns(user_ns);
626 }
627 EXPORT_SYMBOL_GPL(fuse_conn_init);
628
629 void fuse_conn_put(struct fuse_conn *fc)
630 {
631         if (refcount_dec_and_test(&fc->count)) {
632                 if (fc->destroy_req)
633                         fuse_request_free(fc->destroy_req);
634                 put_pid_ns(fc->pid_ns);
635                 put_user_ns(fc->user_ns);
636                 fc->release(fc);
637         }
638 }
639 EXPORT_SYMBOL_GPL(fuse_conn_put);
640
641 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
642 {
643         refcount_inc(&fc->count);
644         return fc;
645 }
646 EXPORT_SYMBOL_GPL(fuse_conn_get);
647
648 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
649 {
650         struct fuse_attr attr;
651         memset(&attr, 0, sizeof(attr));
652
653         attr.mode = mode;
654         attr.ino = FUSE_ROOT_ID;
655         attr.nlink = 1;
656         return fuse_iget(sb, 1, 0, &attr, 0, 0);
657 }
658
659 struct fuse_inode_handle {
660         u64 nodeid;
661         u32 generation;
662 };
663
664 static struct dentry *fuse_get_dentry(struct super_block *sb,
665                                       struct fuse_inode_handle *handle)
666 {
667         struct fuse_conn *fc = get_fuse_conn_super(sb);
668         struct inode *inode;
669         struct dentry *entry;
670         int err = -ESTALE;
671
672         if (handle->nodeid == 0)
673                 goto out_err;
674
675         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
676         if (!inode) {
677                 struct fuse_entry_out outarg;
678                 const struct qstr name = QSTR_INIT(".", 1);
679
680                 if (!fc->export_support)
681                         goto out_err;
682
683                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
684                                        &inode);
685                 if (err && err != -ENOENT)
686                         goto out_err;
687                 if (err || !inode) {
688                         err = -ESTALE;
689                         goto out_err;
690                 }
691                 err = -EIO;
692                 if (get_node_id(inode) != handle->nodeid)
693                         goto out_iput;
694         }
695         err = -ESTALE;
696         if (inode->i_generation != handle->generation)
697                 goto out_iput;
698
699         entry = d_obtain_alias(inode);
700         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
701                 fuse_invalidate_entry_cache(entry);
702
703         return entry;
704
705  out_iput:
706         iput(inode);
707  out_err:
708         return ERR_PTR(err);
709 }
710
711 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
712                            struct inode *parent)
713 {
714         int len = parent ? 6 : 3;
715         u64 nodeid;
716         u32 generation;
717
718         if (*max_len < len) {
719                 *max_len = len;
720                 return  FILEID_INVALID;
721         }
722
723         nodeid = get_fuse_inode(inode)->nodeid;
724         generation = inode->i_generation;
725
726         fh[0] = (u32)(nodeid >> 32);
727         fh[1] = (u32)(nodeid & 0xffffffff);
728         fh[2] = generation;
729
730         if (parent) {
731                 nodeid = get_fuse_inode(parent)->nodeid;
732                 generation = parent->i_generation;
733
734                 fh[3] = (u32)(nodeid >> 32);
735                 fh[4] = (u32)(nodeid & 0xffffffff);
736                 fh[5] = generation;
737         }
738
739         *max_len = len;
740         return parent ? 0x82 : 0x81;
741 }
742
743 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
744                 struct fid *fid, int fh_len, int fh_type)
745 {
746         struct fuse_inode_handle handle;
747
748         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
749                 return NULL;
750
751         handle.nodeid = (u64) fid->raw[0] << 32;
752         handle.nodeid |= (u64) fid->raw[1];
753         handle.generation = fid->raw[2];
754         return fuse_get_dentry(sb, &handle);
755 }
756
757 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
758                 struct fid *fid, int fh_len, int fh_type)
759 {
760         struct fuse_inode_handle parent;
761
762         if (fh_type != 0x82 || fh_len < 6)
763                 return NULL;
764
765         parent.nodeid = (u64) fid->raw[3] << 32;
766         parent.nodeid |= (u64) fid->raw[4];
767         parent.generation = fid->raw[5];
768         return fuse_get_dentry(sb, &parent);
769 }
770
771 static struct dentry *fuse_get_parent(struct dentry *child)
772 {
773         struct inode *child_inode = d_inode(child);
774         struct fuse_conn *fc = get_fuse_conn(child_inode);
775         struct inode *inode;
776         struct dentry *parent;
777         struct fuse_entry_out outarg;
778         const struct qstr name = QSTR_INIT("..", 2);
779         int err;
780
781         if (!fc->export_support)
782                 return ERR_PTR(-ESTALE);
783
784         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
785                                &name, &outarg, &inode);
786         if (err) {
787                 if (err == -ENOENT)
788                         return ERR_PTR(-ESTALE);
789                 return ERR_PTR(err);
790         }
791
792         parent = d_obtain_alias(inode);
793         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
794                 fuse_invalidate_entry_cache(parent);
795
796         return parent;
797 }
798
799 static const struct export_operations fuse_export_operations = {
800         .fh_to_dentry   = fuse_fh_to_dentry,
801         .fh_to_parent   = fuse_fh_to_parent,
802         .encode_fh      = fuse_encode_fh,
803         .get_parent     = fuse_get_parent,
804 };
805
806 static const struct super_operations fuse_super_operations = {
807         .alloc_inode    = fuse_alloc_inode,
808         .destroy_inode  = fuse_destroy_inode,
809         .evict_inode    = fuse_evict_inode,
810         .write_inode    = fuse_write_inode,
811         .drop_inode     = generic_delete_inode,
812         .remount_fs     = fuse_remount_fs,
813         .put_super      = fuse_put_super,
814         .umount_begin   = fuse_umount_begin,
815         .statfs         = fuse_statfs,
816         .show_options   = fuse_show_options,
817 };
818
819 static void sanitize_global_limit(unsigned *limit)
820 {
821         if (*limit == 0)
822                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
823                          sizeof(struct fuse_req);
824
825         if (*limit >= 1 << 16)
826                 *limit = (1 << 16) - 1;
827 }
828
829 static int set_global_limit(const char *val, const struct kernel_param *kp)
830 {
831         int rv;
832
833         rv = param_set_uint(val, kp);
834         if (rv)
835                 return rv;
836
837         sanitize_global_limit((unsigned *)kp->arg);
838
839         return 0;
840 }
841
842 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
843 {
844         int cap_sys_admin = capable(CAP_SYS_ADMIN);
845
846         if (arg->minor < 13)
847                 return;
848
849         sanitize_global_limit(&max_user_bgreq);
850         sanitize_global_limit(&max_user_congthresh);
851
852         if (arg->max_background) {
853                 fc->max_background = arg->max_background;
854
855                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
856                         fc->max_background = max_user_bgreq;
857         }
858         if (arg->congestion_threshold) {
859                 fc->congestion_threshold = arg->congestion_threshold;
860
861                 if (!cap_sys_admin &&
862                     fc->congestion_threshold > max_user_congthresh)
863                         fc->congestion_threshold = max_user_congthresh;
864         }
865 }
866
867 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
868 {
869         struct fuse_init_out *arg = &req->misc.init_out;
870
871         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
872                 fc->conn_error = 1;
873         else {
874                 unsigned long ra_pages;
875
876                 process_init_limits(fc, arg);
877
878                 if (arg->minor >= 6) {
879                         ra_pages = arg->max_readahead / PAGE_SIZE;
880                         if (arg->flags & FUSE_ASYNC_READ)
881                                 fc->async_read = 1;
882                         if (!(arg->flags & FUSE_POSIX_LOCKS))
883                                 fc->no_lock = 1;
884                         if (arg->minor >= 17) {
885                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
886                                         fc->no_flock = 1;
887                         } else {
888                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
889                                         fc->no_flock = 1;
890                         }
891                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
892                                 fc->atomic_o_trunc = 1;
893                         if (arg->minor >= 9) {
894                                 /* LOOKUP has dependency on proto version */
895                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
896                                         fc->export_support = 1;
897                         }
898                         if (arg->flags & FUSE_BIG_WRITES)
899                                 fc->big_writes = 1;
900                         if (arg->flags & FUSE_DONT_MASK)
901                                 fc->dont_mask = 1;
902                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
903                                 fc->auto_inval_data = 1;
904                         if (arg->flags & FUSE_DO_READDIRPLUS) {
905                                 fc->do_readdirplus = 1;
906                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
907                                         fc->readdirplus_auto = 1;
908                         }
909                         if (arg->flags & FUSE_ASYNC_DIO)
910                                 fc->async_dio = 1;
911                         if (arg->flags & FUSE_WRITEBACK_CACHE)
912                                 fc->writeback_cache = 1;
913                         if (arg->flags & FUSE_PARALLEL_DIROPS)
914                                 fc->parallel_dirops = 1;
915                         if (arg->flags & FUSE_HANDLE_KILLPRIV)
916                                 fc->handle_killpriv = 1;
917                         if (arg->time_gran && arg->time_gran <= 1000000000)
918                                 fc->sb->s_time_gran = arg->time_gran;
919                         if ((arg->flags & FUSE_POSIX_ACL)) {
920                                 fc->default_permissions = 1;
921                                 fc->posix_acl = 1;
922                                 fc->sb->s_xattr = fuse_acl_xattr_handlers;
923                         }
924                         if (arg->flags & FUSE_ABORT_ERROR)
925                                 fc->abort_err = 1;
926                 } else {
927                         ra_pages = fc->max_read / PAGE_SIZE;
928                         fc->no_lock = 1;
929                         fc->no_flock = 1;
930                 }
931
932                 fc->sb->s_bdi->ra_pages =
933                                 min(fc->sb->s_bdi->ra_pages, ra_pages);
934                 fc->minor = arg->minor;
935                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
936                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
937                 fc->conn_init = 1;
938         }
939         fuse_set_initialized(fc);
940         wake_up_all(&fc->blocked_waitq);
941 }
942
943 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
944 {
945         struct fuse_init_in *arg = &req->misc.init_in;
946
947         arg->major = FUSE_KERNEL_VERSION;
948         arg->minor = FUSE_KERNEL_MINOR_VERSION;
949         arg->max_readahead = fc->sb->s_bdi->ra_pages * PAGE_SIZE;
950         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
951                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
952                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
953                 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
954                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
955                 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
956                 FUSE_PARALLEL_DIROPS | FUSE_HANDLE_KILLPRIV | FUSE_POSIX_ACL |
957                 FUSE_ABORT_ERROR;
958         req->in.h.opcode = FUSE_INIT;
959         req->in.numargs = 1;
960         req->in.args[0].size = sizeof(*arg);
961         req->in.args[0].value = arg;
962         req->out.numargs = 1;
963         /* Variable length argument used for backward compatibility
964            with interface version < 7.5.  Rest of init_out is zeroed
965            by do_get_request(), so a short reply is not a problem */
966         req->out.argvar = 1;
967         req->out.args[0].size = sizeof(struct fuse_init_out);
968         req->out.args[0].value = &req->misc.init_out;
969         req->end = process_init_reply;
970         fuse_request_send_background(fc, req);
971 }
972
973 static void fuse_free_conn(struct fuse_conn *fc)
974 {
975         WARN_ON(!list_empty(&fc->devices));
976         kfree_rcu(fc, rcu);
977 }
978
979 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
980 {
981         int err;
982         char *suffix = "";
983
984         if (sb->s_bdev) {
985                 suffix = "-fuseblk";
986                 /*
987                  * sb->s_bdi points to blkdev's bdi however we want to redirect
988                  * it to our private bdi...
989                  */
990                 bdi_put(sb->s_bdi);
991                 sb->s_bdi = &noop_backing_dev_info;
992         }
993         err = super_setup_bdi_name(sb, "%u:%u%s", MAJOR(fc->dev),
994                                    MINOR(fc->dev), suffix);
995         if (err)
996                 return err;
997
998         sb->s_bdi->ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
999         /* fuse does it's own writeback accounting */
1000         sb->s_bdi->capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
1001
1002         /*
1003          * For a single fuse filesystem use max 1% of dirty +
1004          * writeback threshold.
1005          *
1006          * This gives about 1M of write buffer for memory maps on a
1007          * machine with 1G and 10% dirty_ratio, which should be more
1008          * than enough.
1009          *
1010          * Privileged users can raise it by writing to
1011          *
1012          *    /sys/class/bdi/<bdi>/max_ratio
1013          */
1014         bdi_set_max_ratio(sb->s_bdi, 1);
1015
1016         return 0;
1017 }
1018
1019 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
1020 {
1021         struct fuse_dev *fud;
1022
1023         fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1024         if (fud) {
1025                 fud->fc = fuse_conn_get(fc);
1026                 fuse_pqueue_init(&fud->pq);
1027
1028                 spin_lock(&fc->lock);
1029                 list_add_tail(&fud->entry, &fc->devices);
1030                 spin_unlock(&fc->lock);
1031         }
1032
1033         return fud;
1034 }
1035 EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1036
1037 void fuse_dev_free(struct fuse_dev *fud)
1038 {
1039         struct fuse_conn *fc = fud->fc;
1040
1041         if (fc) {
1042                 spin_lock(&fc->lock);
1043                 list_del(&fud->entry);
1044                 spin_unlock(&fc->lock);
1045
1046                 fuse_conn_put(fc);
1047         }
1048         kfree(fud);
1049 }
1050 EXPORT_SYMBOL_GPL(fuse_dev_free);
1051
1052 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1053 {
1054         struct fuse_dev *fud;
1055         struct fuse_conn *fc;
1056         struct inode *root;
1057         struct fuse_mount_data d;
1058         struct file *file;
1059         struct dentry *root_dentry;
1060         struct fuse_req *init_req;
1061         int err;
1062         int is_bdev = sb->s_bdev != NULL;
1063
1064         err = -EINVAL;
1065         if (sb->s_flags & SB_MANDLOCK)
1066                 goto err;
1067
1068         sb->s_flags &= ~(SB_NOSEC | SB_I_VERSION);
1069
1070         if (!parse_fuse_opt(data, &d, is_bdev, sb->s_user_ns))
1071                 goto err;
1072
1073         if (is_bdev) {
1074 #ifdef CONFIG_BLOCK
1075                 err = -EINVAL;
1076                 if (!sb_set_blocksize(sb, d.blksize))
1077                         goto err;
1078 #endif
1079         } else {
1080                 sb->s_blocksize = PAGE_SIZE;
1081                 sb->s_blocksize_bits = PAGE_SHIFT;
1082         }
1083         sb->s_magic = FUSE_SUPER_MAGIC;
1084         sb->s_op = &fuse_super_operations;
1085         sb->s_xattr = fuse_xattr_handlers;
1086         sb->s_maxbytes = MAX_LFS_FILESIZE;
1087         sb->s_time_gran = 1;
1088         sb->s_export_op = &fuse_export_operations;
1089         sb->s_iflags |= SB_I_IMA_UNVERIFIABLE_SIGNATURE;
1090         if (sb->s_user_ns != &init_user_ns)
1091                 sb->s_iflags |= SB_I_UNTRUSTED_MOUNTER;
1092
1093         file = fget(d.fd);
1094         err = -EINVAL;
1095         if (!file)
1096                 goto err;
1097
1098         /*
1099          * Require mount to happen from the same user namespace which
1100          * opened /dev/fuse to prevent potential attacks.
1101          */
1102         if (file->f_op != &fuse_dev_operations ||
1103             file->f_cred->user_ns != sb->s_user_ns)
1104                 goto err_fput;
1105
1106         /*
1107          * If we are not in the initial user namespace posix
1108          * acls must be translated.
1109          */
1110         if (sb->s_user_ns != &init_user_ns)
1111                 sb->s_xattr = fuse_no_acl_xattr_handlers;
1112
1113         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1114         err = -ENOMEM;
1115         if (!fc)
1116                 goto err_fput;
1117
1118         fuse_conn_init(fc, sb->s_user_ns);
1119         fc->release = fuse_free_conn;
1120
1121         fud = fuse_dev_alloc(fc);
1122         if (!fud)
1123                 goto err_put_conn;
1124
1125         fc->dev = sb->s_dev;
1126         fc->sb = sb;
1127         err = fuse_bdi_init(fc, sb);
1128         if (err)
1129                 goto err_dev_free;
1130
1131         /* Handle umasking inside the fuse code */
1132         if (sb->s_flags & SB_POSIXACL)
1133                 fc->dont_mask = 1;
1134         sb->s_flags |= SB_POSIXACL;
1135
1136         fc->default_permissions = d.default_permissions;
1137         fc->allow_other = d.allow_other;
1138         fc->user_id = d.user_id;
1139         fc->group_id = d.group_id;
1140         fc->max_read = max_t(unsigned, 4096, d.max_read);
1141
1142         /* Used by get_root_inode() */
1143         sb->s_fs_info = fc;
1144
1145         err = -ENOMEM;
1146         root = fuse_get_root_inode(sb, d.rootmode);
1147         sb->s_d_op = &fuse_root_dentry_operations;
1148         root_dentry = d_make_root(root);
1149         if (!root_dentry)
1150                 goto err_dev_free;
1151         /* Root dentry doesn't have .d_revalidate */
1152         sb->s_d_op = &fuse_dentry_operations;
1153
1154         init_req = fuse_request_alloc(0);
1155         if (!init_req)
1156                 goto err_put_root;
1157         __set_bit(FR_BACKGROUND, &init_req->flags);
1158
1159         if (is_bdev) {
1160                 fc->destroy_req = fuse_request_alloc(0);
1161                 if (!fc->destroy_req)
1162                         goto err_free_init_req;
1163         }
1164
1165         mutex_lock(&fuse_mutex);
1166         err = -EINVAL;
1167         if (file->private_data)
1168                 goto err_unlock;
1169
1170         err = fuse_ctl_add_conn(fc);
1171         if (err)
1172                 goto err_unlock;
1173
1174         list_add_tail(&fc->entry, &fuse_conn_list);
1175         sb->s_root = root_dentry;
1176         file->private_data = fud;
1177         mutex_unlock(&fuse_mutex);
1178         /*
1179          * atomic_dec_and_test() in fput() provides the necessary
1180          * memory barrier for file->private_data to be visible on all
1181          * CPUs after this
1182          */
1183         fput(file);
1184
1185         fuse_send_init(fc, init_req);
1186
1187         return 0;
1188
1189  err_unlock:
1190         mutex_unlock(&fuse_mutex);
1191  err_free_init_req:
1192         fuse_request_free(init_req);
1193  err_put_root:
1194         dput(root_dentry);
1195  err_dev_free:
1196         fuse_dev_free(fud);
1197  err_put_conn:
1198         fuse_conn_put(fc);
1199         sb->s_fs_info = NULL;
1200  err_fput:
1201         fput(file);
1202  err:
1203         return err;
1204 }
1205
1206 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1207                        int flags, const char *dev_name,
1208                        void *raw_data)
1209 {
1210         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1211 }
1212
1213 static void fuse_kill_sb_anon(struct super_block *sb)
1214 {
1215         struct fuse_conn *fc = get_fuse_conn_super(sb);
1216
1217         if (fc) {
1218                 down_write(&fc->killsb);
1219                 fc->sb = NULL;
1220                 up_write(&fc->killsb);
1221         }
1222
1223         kill_anon_super(sb);
1224 }
1225
1226 static struct file_system_type fuse_fs_type = {
1227         .owner          = THIS_MODULE,
1228         .name           = "fuse",
1229         .fs_flags       = FS_HAS_SUBTYPE | FS_USERNS_MOUNT,
1230         .mount          = fuse_mount,
1231         .kill_sb        = fuse_kill_sb_anon,
1232 };
1233 MODULE_ALIAS_FS("fuse");
1234
1235 #ifdef CONFIG_BLOCK
1236 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1237                            int flags, const char *dev_name,
1238                            void *raw_data)
1239 {
1240         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1241 }
1242
1243 static void fuse_kill_sb_blk(struct super_block *sb)
1244 {
1245         struct fuse_conn *fc = get_fuse_conn_super(sb);
1246
1247         if (fc) {
1248                 down_write(&fc->killsb);
1249                 fc->sb = NULL;
1250                 up_write(&fc->killsb);
1251         }
1252
1253         kill_block_super(sb);
1254 }
1255
1256 static struct file_system_type fuseblk_fs_type = {
1257         .owner          = THIS_MODULE,
1258         .name           = "fuseblk",
1259         .mount          = fuse_mount_blk,
1260         .kill_sb        = fuse_kill_sb_blk,
1261         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1262 };
1263 MODULE_ALIAS_FS("fuseblk");
1264
1265 static inline int register_fuseblk(void)
1266 {
1267         return register_filesystem(&fuseblk_fs_type);
1268 }
1269
1270 static inline void unregister_fuseblk(void)
1271 {
1272         unregister_filesystem(&fuseblk_fs_type);
1273 }
1274 #else
1275 static inline int register_fuseblk(void)
1276 {
1277         return 0;
1278 }
1279
1280 static inline void unregister_fuseblk(void)
1281 {
1282 }
1283 #endif
1284
1285 static void fuse_inode_init_once(void *foo)
1286 {
1287         struct inode *inode = foo;
1288
1289         inode_init_once(inode);
1290 }
1291
1292 static int __init fuse_fs_init(void)
1293 {
1294         int err;
1295
1296         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1297                         sizeof(struct fuse_inode), 0,
1298                         SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT|SLAB_RECLAIM_ACCOUNT,
1299                         fuse_inode_init_once);
1300         err = -ENOMEM;
1301         if (!fuse_inode_cachep)
1302                 goto out;
1303
1304         err = register_fuseblk();
1305         if (err)
1306                 goto out2;
1307
1308         err = register_filesystem(&fuse_fs_type);
1309         if (err)
1310                 goto out3;
1311
1312         return 0;
1313
1314  out3:
1315         unregister_fuseblk();
1316  out2:
1317         kmem_cache_destroy(fuse_inode_cachep);
1318  out:
1319         return err;
1320 }
1321
1322 static void fuse_fs_cleanup(void)
1323 {
1324         unregister_filesystem(&fuse_fs_type);
1325         unregister_fuseblk();
1326
1327         /*
1328          * Make sure all delayed rcu free inodes are flushed before we
1329          * destroy cache.
1330          */
1331         rcu_barrier();
1332         kmem_cache_destroy(fuse_inode_cachep);
1333 }
1334
1335 static struct kobject *fuse_kobj;
1336
1337 static int fuse_sysfs_init(void)
1338 {
1339         int err;
1340
1341         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1342         if (!fuse_kobj) {
1343                 err = -ENOMEM;
1344                 goto out_err;
1345         }
1346
1347         err = sysfs_create_mount_point(fuse_kobj, "connections");
1348         if (err)
1349                 goto out_fuse_unregister;
1350
1351         return 0;
1352
1353  out_fuse_unregister:
1354         kobject_put(fuse_kobj);
1355  out_err:
1356         return err;
1357 }
1358
1359 static void fuse_sysfs_cleanup(void)
1360 {
1361         sysfs_remove_mount_point(fuse_kobj, "connections");
1362         kobject_put(fuse_kobj);
1363 }
1364
1365 static int __init fuse_init(void)
1366 {
1367         int res;
1368
1369         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1370                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1371
1372         INIT_LIST_HEAD(&fuse_conn_list);
1373         res = fuse_fs_init();
1374         if (res)
1375                 goto err;
1376
1377         res = fuse_dev_init();
1378         if (res)
1379                 goto err_fs_cleanup;
1380
1381         res = fuse_sysfs_init();
1382         if (res)
1383                 goto err_dev_cleanup;
1384
1385         res = fuse_ctl_init();
1386         if (res)
1387                 goto err_sysfs_cleanup;
1388
1389         sanitize_global_limit(&max_user_bgreq);
1390         sanitize_global_limit(&max_user_congthresh);
1391
1392         return 0;
1393
1394  err_sysfs_cleanup:
1395         fuse_sysfs_cleanup();
1396  err_dev_cleanup:
1397         fuse_dev_cleanup();
1398  err_fs_cleanup:
1399         fuse_fs_cleanup();
1400  err:
1401         return res;
1402 }
1403
1404 static void __exit fuse_exit(void)
1405 {
1406         printk(KERN_DEBUG "fuse exit\n");
1407
1408         fuse_ctl_cleanup();
1409         fuse_sysfs_cleanup();
1410         fuse_fs_cleanup();
1411         fuse_dev_cleanup();
1412 }
1413
1414 module_init(fuse_init);
1415 module_exit(fuse_exit);