xref: /openbmc/linux/fs/fuse/inode.c (revision d2999e1b)
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 
24 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
25 MODULE_DESCRIPTION("Filesystem in Userspace");
26 MODULE_LICENSE("GPL");
27 
28 static struct kmem_cache *fuse_inode_cachep;
29 struct list_head fuse_conn_list;
30 DEFINE_MUTEX(fuse_mutex);
31 
32 static int set_global_limit(const char *val, struct kernel_param *kp);
33 
34 unsigned max_user_bgreq;
35 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
36 		  &max_user_bgreq, 0644);
37 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
38 MODULE_PARM_DESC(max_user_bgreq,
39  "Global limit for the maximum number of backgrounded requests an "
40  "unprivileged user can set");
41 
42 unsigned max_user_congthresh;
43 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
44 		  &max_user_congthresh, 0644);
45 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
46 MODULE_PARM_DESC(max_user_congthresh,
47  "Global limit for the maximum congestion threshold an "
48  "unprivileged user can set");
49 
50 #define FUSE_SUPER_MAGIC 0x65735546
51 
52 #define FUSE_DEFAULT_BLKSIZE 512
53 
54 /** Maximum number of outstanding background requests */
55 #define FUSE_DEFAULT_MAX_BACKGROUND 12
56 
57 /** Congestion starts at 75% of maximum */
58 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
59 
60 struct fuse_mount_data {
61 	int fd;
62 	unsigned rootmode;
63 	kuid_t user_id;
64 	kgid_t group_id;
65 	unsigned fd_present:1;
66 	unsigned rootmode_present:1;
67 	unsigned user_id_present:1;
68 	unsigned group_id_present:1;
69 	unsigned flags;
70 	unsigned max_read;
71 	unsigned blksize;
72 };
73 
74 struct fuse_forget_link *fuse_alloc_forget(void)
75 {
76 	return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
77 }
78 
79 static struct inode *fuse_alloc_inode(struct super_block *sb)
80 {
81 	struct inode *inode;
82 	struct fuse_inode *fi;
83 
84 	inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
85 	if (!inode)
86 		return NULL;
87 
88 	fi = get_fuse_inode(inode);
89 	fi->i_time = 0;
90 	fi->nodeid = 0;
91 	fi->nlookup = 0;
92 	fi->attr_version = 0;
93 	fi->writectr = 0;
94 	fi->orig_ino = 0;
95 	fi->state = 0;
96 	INIT_LIST_HEAD(&fi->write_files);
97 	INIT_LIST_HEAD(&fi->queued_writes);
98 	INIT_LIST_HEAD(&fi->writepages);
99 	init_waitqueue_head(&fi->page_waitq);
100 	fi->forget = fuse_alloc_forget();
101 	if (!fi->forget) {
102 		kmem_cache_free(fuse_inode_cachep, inode);
103 		return NULL;
104 	}
105 
106 	return inode;
107 }
108 
109 static void fuse_i_callback(struct rcu_head *head)
110 {
111 	struct inode *inode = container_of(head, struct inode, i_rcu);
112 	kmem_cache_free(fuse_inode_cachep, inode);
113 }
114 
115 static void fuse_destroy_inode(struct inode *inode)
116 {
117 	struct fuse_inode *fi = get_fuse_inode(inode);
118 	BUG_ON(!list_empty(&fi->write_files));
119 	BUG_ON(!list_empty(&fi->queued_writes));
120 	kfree(fi->forget);
121 	call_rcu(&inode->i_rcu, fuse_i_callback);
122 }
123 
124 static void fuse_evict_inode(struct inode *inode)
125 {
126 	truncate_inode_pages_final(&inode->i_data);
127 	clear_inode(inode);
128 	if (inode->i_sb->s_flags & MS_ACTIVE) {
129 		struct fuse_conn *fc = get_fuse_conn(inode);
130 		struct fuse_inode *fi = get_fuse_inode(inode);
131 		fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
132 		fi->forget = NULL;
133 	}
134 }
135 
136 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
137 {
138 	sync_filesystem(sb);
139 	if (*flags & MS_MANDLOCK)
140 		return -EINVAL;
141 
142 	return 0;
143 }
144 
145 /*
146  * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
147  * so that it will fit.
148  */
149 static ino_t fuse_squash_ino(u64 ino64)
150 {
151 	ino_t ino = (ino_t) ino64;
152 	if (sizeof(ino_t) < sizeof(u64))
153 		ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
154 	return ino;
155 }
156 
157 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
158 				   u64 attr_valid)
159 {
160 	struct fuse_conn *fc = get_fuse_conn(inode);
161 	struct fuse_inode *fi = get_fuse_inode(inode);
162 
163 	fi->attr_version = ++fc->attr_version;
164 	fi->i_time = attr_valid;
165 
166 	inode->i_ino     = fuse_squash_ino(attr->ino);
167 	inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
168 	set_nlink(inode, attr->nlink);
169 	inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
170 	inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
171 	inode->i_blocks  = attr->blocks;
172 	inode->i_atime.tv_sec   = attr->atime;
173 	inode->i_atime.tv_nsec  = attr->atimensec;
174 	/* mtime from server may be stale due to local buffered write */
175 	if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
176 		inode->i_mtime.tv_sec   = attr->mtime;
177 		inode->i_mtime.tv_nsec  = attr->mtimensec;
178 		inode->i_ctime.tv_sec   = attr->ctime;
179 		inode->i_ctime.tv_nsec  = attr->ctimensec;
180 	}
181 
182 	if (attr->blksize != 0)
183 		inode->i_blkbits = ilog2(attr->blksize);
184 	else
185 		inode->i_blkbits = inode->i_sb->s_blocksize_bits;
186 
187 	/*
188 	 * Don't set the sticky bit in i_mode, unless we want the VFS
189 	 * to check permissions.  This prevents failures due to the
190 	 * check in may_delete().
191 	 */
192 	fi->orig_i_mode = inode->i_mode;
193 	if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
194 		inode->i_mode &= ~S_ISVTX;
195 
196 	fi->orig_ino = attr->ino;
197 }
198 
199 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
200 			    u64 attr_valid, u64 attr_version)
201 {
202 	struct fuse_conn *fc = get_fuse_conn(inode);
203 	struct fuse_inode *fi = get_fuse_inode(inode);
204 	bool is_wb = fc->writeback_cache;
205 	loff_t oldsize;
206 	struct timespec old_mtime;
207 
208 	spin_lock(&fc->lock);
209 	if ((attr_version != 0 && fi->attr_version > attr_version) ||
210 	    test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
211 		spin_unlock(&fc->lock);
212 		return;
213 	}
214 
215 	old_mtime = inode->i_mtime;
216 	fuse_change_attributes_common(inode, attr, attr_valid);
217 
218 	oldsize = inode->i_size;
219 	/*
220 	 * In case of writeback_cache enabled, the cached writes beyond EOF
221 	 * extend local i_size without keeping userspace server in sync. So,
222 	 * attr->size coming from server can be stale. We cannot trust it.
223 	 */
224 	if (!is_wb || !S_ISREG(inode->i_mode))
225 		i_size_write(inode, attr->size);
226 	spin_unlock(&fc->lock);
227 
228 	if (!is_wb && S_ISREG(inode->i_mode)) {
229 		bool inval = false;
230 
231 		if (oldsize != attr->size) {
232 			truncate_pagecache(inode, attr->size);
233 			inval = true;
234 		} else if (fc->auto_inval_data) {
235 			struct timespec new_mtime = {
236 				.tv_sec = attr->mtime,
237 				.tv_nsec = attr->mtimensec,
238 			};
239 
240 			/*
241 			 * Auto inval mode also checks and invalidates if mtime
242 			 * has changed.
243 			 */
244 			if (!timespec_equal(&old_mtime, &new_mtime))
245 				inval = true;
246 		}
247 
248 		if (inval)
249 			invalidate_inode_pages2(inode->i_mapping);
250 	}
251 }
252 
253 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
254 {
255 	inode->i_mode = attr->mode & S_IFMT;
256 	inode->i_size = attr->size;
257 	inode->i_mtime.tv_sec  = attr->mtime;
258 	inode->i_mtime.tv_nsec = attr->mtimensec;
259 	inode->i_ctime.tv_sec  = attr->ctime;
260 	inode->i_ctime.tv_nsec = attr->ctimensec;
261 	if (S_ISREG(inode->i_mode)) {
262 		fuse_init_common(inode);
263 		fuse_init_file_inode(inode);
264 	} else if (S_ISDIR(inode->i_mode))
265 		fuse_init_dir(inode);
266 	else if (S_ISLNK(inode->i_mode))
267 		fuse_init_symlink(inode);
268 	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
269 		 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
270 		fuse_init_common(inode);
271 		init_special_inode(inode, inode->i_mode,
272 				   new_decode_dev(attr->rdev));
273 	} else
274 		BUG();
275 }
276 
277 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
278 {
279 	u64 nodeid = *(u64 *) _nodeidp;
280 	if (get_node_id(inode) == nodeid)
281 		return 1;
282 	else
283 		return 0;
284 }
285 
286 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
287 {
288 	u64 nodeid = *(u64 *) _nodeidp;
289 	get_fuse_inode(inode)->nodeid = nodeid;
290 	return 0;
291 }
292 
293 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
294 			int generation, struct fuse_attr *attr,
295 			u64 attr_valid, u64 attr_version)
296 {
297 	struct inode *inode;
298 	struct fuse_inode *fi;
299 	struct fuse_conn *fc = get_fuse_conn_super(sb);
300 
301  retry:
302 	inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
303 	if (!inode)
304 		return NULL;
305 
306 	if ((inode->i_state & I_NEW)) {
307 		inode->i_flags |= S_NOATIME;
308 		if (!fc->writeback_cache || !S_ISREG(attr->mode))
309 			inode->i_flags |= S_NOCMTIME;
310 		inode->i_generation = generation;
311 		inode->i_data.backing_dev_info = &fc->bdi;
312 		fuse_init_inode(inode, attr);
313 		unlock_new_inode(inode);
314 	} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
315 		/* Inode has changed type, any I/O on the old should fail */
316 		make_bad_inode(inode);
317 		iput(inode);
318 		goto retry;
319 	}
320 
321 	fi = get_fuse_inode(inode);
322 	spin_lock(&fc->lock);
323 	fi->nlookup++;
324 	spin_unlock(&fc->lock);
325 	fuse_change_attributes(inode, attr, attr_valid, attr_version);
326 
327 	return inode;
328 }
329 
330 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
331 			     loff_t offset, loff_t len)
332 {
333 	struct inode *inode;
334 	pgoff_t pg_start;
335 	pgoff_t pg_end;
336 
337 	inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
338 	if (!inode)
339 		return -ENOENT;
340 
341 	fuse_invalidate_attr(inode);
342 	if (offset >= 0) {
343 		pg_start = offset >> PAGE_CACHE_SHIFT;
344 		if (len <= 0)
345 			pg_end = -1;
346 		else
347 			pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
348 		invalidate_inode_pages2_range(inode->i_mapping,
349 					      pg_start, pg_end);
350 	}
351 	iput(inode);
352 	return 0;
353 }
354 
355 static void fuse_umount_begin(struct super_block *sb)
356 {
357 	fuse_abort_conn(get_fuse_conn_super(sb));
358 }
359 
360 static void fuse_send_destroy(struct fuse_conn *fc)
361 {
362 	struct fuse_req *req = fc->destroy_req;
363 	if (req && fc->conn_init) {
364 		fc->destroy_req = NULL;
365 		req->in.h.opcode = FUSE_DESTROY;
366 		req->force = 1;
367 		req->background = 0;
368 		fuse_request_send(fc, req);
369 		fuse_put_request(fc, req);
370 	}
371 }
372 
373 static void fuse_bdi_destroy(struct fuse_conn *fc)
374 {
375 	if (fc->bdi_initialized)
376 		bdi_destroy(&fc->bdi);
377 }
378 
379 void fuse_conn_kill(struct fuse_conn *fc)
380 {
381 	spin_lock(&fc->lock);
382 	fc->connected = 0;
383 	fc->blocked = 0;
384 	fc->initialized = 1;
385 	spin_unlock(&fc->lock);
386 	/* Flush all readers on this fs */
387 	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
388 	wake_up_all(&fc->waitq);
389 	wake_up_all(&fc->blocked_waitq);
390 	wake_up_all(&fc->reserved_req_waitq);
391 }
392 EXPORT_SYMBOL_GPL(fuse_conn_kill);
393 
394 static void fuse_put_super(struct super_block *sb)
395 {
396 	struct fuse_conn *fc = get_fuse_conn_super(sb);
397 
398 	fuse_send_destroy(fc);
399 
400 	fuse_conn_kill(fc);
401 	mutex_lock(&fuse_mutex);
402 	list_del(&fc->entry);
403 	fuse_ctl_remove_conn(fc);
404 	mutex_unlock(&fuse_mutex);
405 	fuse_bdi_destroy(fc);
406 
407 	fuse_conn_put(fc);
408 }
409 
410 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
411 {
412 	stbuf->f_type    = FUSE_SUPER_MAGIC;
413 	stbuf->f_bsize   = attr->bsize;
414 	stbuf->f_frsize  = attr->frsize;
415 	stbuf->f_blocks  = attr->blocks;
416 	stbuf->f_bfree   = attr->bfree;
417 	stbuf->f_bavail  = attr->bavail;
418 	stbuf->f_files   = attr->files;
419 	stbuf->f_ffree   = attr->ffree;
420 	stbuf->f_namelen = attr->namelen;
421 	/* fsid is left zero */
422 }
423 
424 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
425 {
426 	struct super_block *sb = dentry->d_sb;
427 	struct fuse_conn *fc = get_fuse_conn_super(sb);
428 	struct fuse_req *req;
429 	struct fuse_statfs_out outarg;
430 	int err;
431 
432 	if (!fuse_allow_current_process(fc)) {
433 		buf->f_type = FUSE_SUPER_MAGIC;
434 		return 0;
435 	}
436 
437 	req = fuse_get_req_nopages(fc);
438 	if (IS_ERR(req))
439 		return PTR_ERR(req);
440 
441 	memset(&outarg, 0, sizeof(outarg));
442 	req->in.numargs = 0;
443 	req->in.h.opcode = FUSE_STATFS;
444 	req->in.h.nodeid = get_node_id(dentry->d_inode);
445 	req->out.numargs = 1;
446 	req->out.args[0].size =
447 		fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
448 	req->out.args[0].value = &outarg;
449 	fuse_request_send(fc, req);
450 	err = req->out.h.error;
451 	if (!err)
452 		convert_fuse_statfs(buf, &outarg.st);
453 	fuse_put_request(fc, req);
454 	return err;
455 }
456 
457 enum {
458 	OPT_FD,
459 	OPT_ROOTMODE,
460 	OPT_USER_ID,
461 	OPT_GROUP_ID,
462 	OPT_DEFAULT_PERMISSIONS,
463 	OPT_ALLOW_OTHER,
464 	OPT_MAX_READ,
465 	OPT_BLKSIZE,
466 	OPT_ERR
467 };
468 
469 static const match_table_t tokens = {
470 	{OPT_FD,			"fd=%u"},
471 	{OPT_ROOTMODE,			"rootmode=%o"},
472 	{OPT_USER_ID,			"user_id=%u"},
473 	{OPT_GROUP_ID,			"group_id=%u"},
474 	{OPT_DEFAULT_PERMISSIONS,	"default_permissions"},
475 	{OPT_ALLOW_OTHER,		"allow_other"},
476 	{OPT_MAX_READ,			"max_read=%u"},
477 	{OPT_BLKSIZE,			"blksize=%u"},
478 	{OPT_ERR,			NULL}
479 };
480 
481 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
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 		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 (match_int(&args[0], &value))
515 				return 0;
516 			d->user_id = make_kuid(current_user_ns(), value);
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 (match_int(&args[0], &value))
524 				return 0;
525 			d->group_id = make_kgid(current_user_ns(), value);
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->flags |= FUSE_DEFAULT_PERMISSIONS;
533 			break;
534 
535 		case OPT_ALLOW_OTHER:
536 			d->flags |= FUSE_ALLOW_OTHER;
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->flags & FUSE_DEFAULT_PERMISSIONS)
571 		seq_puts(m, ",default_permissions");
572 	if (fc->flags & FUSE_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 void fuse_conn_init(struct fuse_conn *fc)
582 {
583 	memset(fc, 0, sizeof(*fc));
584 	spin_lock_init(&fc->lock);
585 	init_rwsem(&fc->killsb);
586 	atomic_set(&fc->count, 1);
587 	init_waitqueue_head(&fc->waitq);
588 	init_waitqueue_head(&fc->blocked_waitq);
589 	init_waitqueue_head(&fc->reserved_req_waitq);
590 	INIT_LIST_HEAD(&fc->pending);
591 	INIT_LIST_HEAD(&fc->processing);
592 	INIT_LIST_HEAD(&fc->io);
593 	INIT_LIST_HEAD(&fc->interrupts);
594 	INIT_LIST_HEAD(&fc->bg_queue);
595 	INIT_LIST_HEAD(&fc->entry);
596 	fc->forget_list_tail = &fc->forget_list_head;
597 	atomic_set(&fc->num_waiting, 0);
598 	fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
599 	fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
600 	fc->khctr = 0;
601 	fc->polled_files = RB_ROOT;
602 	fc->reqctr = 0;
603 	fc->blocked = 0;
604 	fc->initialized = 0;
605 	fc->attr_version = 1;
606 	get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
607 }
608 EXPORT_SYMBOL_GPL(fuse_conn_init);
609 
610 void fuse_conn_put(struct fuse_conn *fc)
611 {
612 	if (atomic_dec_and_test(&fc->count)) {
613 		if (fc->destroy_req)
614 			fuse_request_free(fc->destroy_req);
615 		fc->release(fc);
616 	}
617 }
618 EXPORT_SYMBOL_GPL(fuse_conn_put);
619 
620 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
621 {
622 	atomic_inc(&fc->count);
623 	return fc;
624 }
625 EXPORT_SYMBOL_GPL(fuse_conn_get);
626 
627 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
628 {
629 	struct fuse_attr attr;
630 	memset(&attr, 0, sizeof(attr));
631 
632 	attr.mode = mode;
633 	attr.ino = FUSE_ROOT_ID;
634 	attr.nlink = 1;
635 	return fuse_iget(sb, 1, 0, &attr, 0, 0);
636 }
637 
638 struct fuse_inode_handle {
639 	u64 nodeid;
640 	u32 generation;
641 };
642 
643 static struct dentry *fuse_get_dentry(struct super_block *sb,
644 				      struct fuse_inode_handle *handle)
645 {
646 	struct fuse_conn *fc = get_fuse_conn_super(sb);
647 	struct inode *inode;
648 	struct dentry *entry;
649 	int err = -ESTALE;
650 
651 	if (handle->nodeid == 0)
652 		goto out_err;
653 
654 	inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
655 	if (!inode) {
656 		struct fuse_entry_out outarg;
657 		struct qstr name;
658 
659 		if (!fc->export_support)
660 			goto out_err;
661 
662 		name.len = 1;
663 		name.name = ".";
664 		err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
665 				       &inode);
666 		if (err && err != -ENOENT)
667 			goto out_err;
668 		if (err || !inode) {
669 			err = -ESTALE;
670 			goto out_err;
671 		}
672 		err = -EIO;
673 		if (get_node_id(inode) != handle->nodeid)
674 			goto out_iput;
675 	}
676 	err = -ESTALE;
677 	if (inode->i_generation != handle->generation)
678 		goto out_iput;
679 
680 	entry = d_obtain_alias(inode);
681 	if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
682 		fuse_invalidate_entry_cache(entry);
683 
684 	return entry;
685 
686  out_iput:
687 	iput(inode);
688  out_err:
689 	return ERR_PTR(err);
690 }
691 
692 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
693 			   struct inode *parent)
694 {
695 	int len = parent ? 6 : 3;
696 	u64 nodeid;
697 	u32 generation;
698 
699 	if (*max_len < len) {
700 		*max_len = len;
701 		return  FILEID_INVALID;
702 	}
703 
704 	nodeid = get_fuse_inode(inode)->nodeid;
705 	generation = inode->i_generation;
706 
707 	fh[0] = (u32)(nodeid >> 32);
708 	fh[1] = (u32)(nodeid & 0xffffffff);
709 	fh[2] = generation;
710 
711 	if (parent) {
712 		nodeid = get_fuse_inode(parent)->nodeid;
713 		generation = parent->i_generation;
714 
715 		fh[3] = (u32)(nodeid >> 32);
716 		fh[4] = (u32)(nodeid & 0xffffffff);
717 		fh[5] = generation;
718 	}
719 
720 	*max_len = len;
721 	return parent ? 0x82 : 0x81;
722 }
723 
724 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
725 		struct fid *fid, int fh_len, int fh_type)
726 {
727 	struct fuse_inode_handle handle;
728 
729 	if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
730 		return NULL;
731 
732 	handle.nodeid = (u64) fid->raw[0] << 32;
733 	handle.nodeid |= (u64) fid->raw[1];
734 	handle.generation = fid->raw[2];
735 	return fuse_get_dentry(sb, &handle);
736 }
737 
738 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
739 		struct fid *fid, int fh_len, int fh_type)
740 {
741 	struct fuse_inode_handle parent;
742 
743 	if (fh_type != 0x82 || fh_len < 6)
744 		return NULL;
745 
746 	parent.nodeid = (u64) fid->raw[3] << 32;
747 	parent.nodeid |= (u64) fid->raw[4];
748 	parent.generation = fid->raw[5];
749 	return fuse_get_dentry(sb, &parent);
750 }
751 
752 static struct dentry *fuse_get_parent(struct dentry *child)
753 {
754 	struct inode *child_inode = child->d_inode;
755 	struct fuse_conn *fc = get_fuse_conn(child_inode);
756 	struct inode *inode;
757 	struct dentry *parent;
758 	struct fuse_entry_out outarg;
759 	struct qstr name;
760 	int err;
761 
762 	if (!fc->export_support)
763 		return ERR_PTR(-ESTALE);
764 
765 	name.len = 2;
766 	name.name = "..";
767 	err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
768 			       &name, &outarg, &inode);
769 	if (err) {
770 		if (err == -ENOENT)
771 			return ERR_PTR(-ESTALE);
772 		return ERR_PTR(err);
773 	}
774 
775 	parent = d_obtain_alias(inode);
776 	if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
777 		fuse_invalidate_entry_cache(parent);
778 
779 	return parent;
780 }
781 
782 static const struct export_operations fuse_export_operations = {
783 	.fh_to_dentry	= fuse_fh_to_dentry,
784 	.fh_to_parent	= fuse_fh_to_parent,
785 	.encode_fh	= fuse_encode_fh,
786 	.get_parent	= fuse_get_parent,
787 };
788 
789 static const struct super_operations fuse_super_operations = {
790 	.alloc_inode    = fuse_alloc_inode,
791 	.destroy_inode  = fuse_destroy_inode,
792 	.evict_inode	= fuse_evict_inode,
793 	.write_inode	= fuse_write_inode,
794 	.drop_inode	= generic_delete_inode,
795 	.remount_fs	= fuse_remount_fs,
796 	.put_super	= fuse_put_super,
797 	.umount_begin	= fuse_umount_begin,
798 	.statfs		= fuse_statfs,
799 	.show_options	= fuse_show_options,
800 };
801 
802 static void sanitize_global_limit(unsigned *limit)
803 {
804 	if (*limit == 0)
805 		*limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
806 			 sizeof(struct fuse_req);
807 
808 	if (*limit >= 1 << 16)
809 		*limit = (1 << 16) - 1;
810 }
811 
812 static int set_global_limit(const char *val, struct kernel_param *kp)
813 {
814 	int rv;
815 
816 	rv = param_set_uint(val, kp);
817 	if (rv)
818 		return rv;
819 
820 	sanitize_global_limit((unsigned *)kp->arg);
821 
822 	return 0;
823 }
824 
825 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
826 {
827 	int cap_sys_admin = capable(CAP_SYS_ADMIN);
828 
829 	if (arg->minor < 13)
830 		return;
831 
832 	sanitize_global_limit(&max_user_bgreq);
833 	sanitize_global_limit(&max_user_congthresh);
834 
835 	if (arg->max_background) {
836 		fc->max_background = arg->max_background;
837 
838 		if (!cap_sys_admin && fc->max_background > max_user_bgreq)
839 			fc->max_background = max_user_bgreq;
840 	}
841 	if (arg->congestion_threshold) {
842 		fc->congestion_threshold = arg->congestion_threshold;
843 
844 		if (!cap_sys_admin &&
845 		    fc->congestion_threshold > max_user_congthresh)
846 			fc->congestion_threshold = max_user_congthresh;
847 	}
848 }
849 
850 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
851 {
852 	struct fuse_init_out *arg = &req->misc.init_out;
853 
854 	if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
855 		fc->conn_error = 1;
856 	else {
857 		unsigned long ra_pages;
858 
859 		process_init_limits(fc, arg);
860 
861 		if (arg->minor >= 6) {
862 			ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
863 			if (arg->flags & FUSE_ASYNC_READ)
864 				fc->async_read = 1;
865 			if (!(arg->flags & FUSE_POSIX_LOCKS))
866 				fc->no_lock = 1;
867 			if (arg->minor >= 17) {
868 				if (!(arg->flags & FUSE_FLOCK_LOCKS))
869 					fc->no_flock = 1;
870 			} else {
871 				if (!(arg->flags & FUSE_POSIX_LOCKS))
872 					fc->no_flock = 1;
873 			}
874 			if (arg->flags & FUSE_ATOMIC_O_TRUNC)
875 				fc->atomic_o_trunc = 1;
876 			if (arg->minor >= 9) {
877 				/* LOOKUP has dependency on proto version */
878 				if (arg->flags & FUSE_EXPORT_SUPPORT)
879 					fc->export_support = 1;
880 			}
881 			if (arg->flags & FUSE_BIG_WRITES)
882 				fc->big_writes = 1;
883 			if (arg->flags & FUSE_DONT_MASK)
884 				fc->dont_mask = 1;
885 			if (arg->flags & FUSE_AUTO_INVAL_DATA)
886 				fc->auto_inval_data = 1;
887 			if (arg->flags & FUSE_DO_READDIRPLUS) {
888 				fc->do_readdirplus = 1;
889 				if (arg->flags & FUSE_READDIRPLUS_AUTO)
890 					fc->readdirplus_auto = 1;
891 			}
892 			if (arg->flags & FUSE_ASYNC_DIO)
893 				fc->async_dio = 1;
894 			if (arg->flags & FUSE_WRITEBACK_CACHE)
895 				fc->writeback_cache = 1;
896 			if (arg->time_gran && arg->time_gran <= 1000000000)
897 				fc->sb->s_time_gran = arg->time_gran;
898 			else
899 				fc->sb->s_time_gran = 1000000000;
900 
901 		} else {
902 			ra_pages = fc->max_read / PAGE_CACHE_SIZE;
903 			fc->no_lock = 1;
904 			fc->no_flock = 1;
905 		}
906 
907 		fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
908 		fc->minor = arg->minor;
909 		fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
910 		fc->max_write = max_t(unsigned, 4096, fc->max_write);
911 		fc->conn_init = 1;
912 	}
913 	fc->initialized = 1;
914 	wake_up_all(&fc->blocked_waitq);
915 }
916 
917 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
918 {
919 	struct fuse_init_in *arg = &req->misc.init_in;
920 
921 	arg->major = FUSE_KERNEL_VERSION;
922 	arg->minor = FUSE_KERNEL_MINOR_VERSION;
923 	arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
924 	arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
925 		FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
926 		FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
927 		FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
928 		FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
929 		FUSE_WRITEBACK_CACHE;
930 	req->in.h.opcode = FUSE_INIT;
931 	req->in.numargs = 1;
932 	req->in.args[0].size = sizeof(*arg);
933 	req->in.args[0].value = arg;
934 	req->out.numargs = 1;
935 	/* Variable length argument used for backward compatibility
936 	   with interface version < 7.5.  Rest of init_out is zeroed
937 	   by do_get_request(), so a short reply is not a problem */
938 	req->out.argvar = 1;
939 	req->out.args[0].size = sizeof(struct fuse_init_out);
940 	req->out.args[0].value = &req->misc.init_out;
941 	req->end = process_init_reply;
942 	fuse_request_send_background(fc, req);
943 }
944 
945 static void fuse_free_conn(struct fuse_conn *fc)
946 {
947 	kfree_rcu(fc, rcu);
948 }
949 
950 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
951 {
952 	int err;
953 
954 	fc->bdi.name = "fuse";
955 	fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
956 	/* fuse does it's own writeback accounting */
957 	fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
958 
959 	err = bdi_init(&fc->bdi);
960 	if (err)
961 		return err;
962 
963 	fc->bdi_initialized = 1;
964 
965 	if (sb->s_bdev) {
966 		err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
967 				    MAJOR(fc->dev), MINOR(fc->dev));
968 	} else {
969 		err = bdi_register_dev(&fc->bdi, fc->dev);
970 	}
971 
972 	if (err)
973 		return err;
974 
975 	/*
976 	 * For a single fuse filesystem use max 1% of dirty +
977 	 * writeback threshold.
978 	 *
979 	 * This gives about 1M of write buffer for memory maps on a
980 	 * machine with 1G and 10% dirty_ratio, which should be more
981 	 * than enough.
982 	 *
983 	 * Privileged users can raise it by writing to
984 	 *
985 	 *    /sys/class/bdi/<bdi>/max_ratio
986 	 */
987 	bdi_set_max_ratio(&fc->bdi, 1);
988 
989 	return 0;
990 }
991 
992 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
993 {
994 	struct fuse_conn *fc;
995 	struct inode *root;
996 	struct fuse_mount_data d;
997 	struct file *file;
998 	struct dentry *root_dentry;
999 	struct fuse_req *init_req;
1000 	int err;
1001 	int is_bdev = sb->s_bdev != NULL;
1002 
1003 	err = -EINVAL;
1004 	if (sb->s_flags & MS_MANDLOCK)
1005 		goto err;
1006 
1007 	sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1008 
1009 	if (!parse_fuse_opt((char *) data, &d, is_bdev))
1010 		goto err;
1011 
1012 	if (is_bdev) {
1013 #ifdef CONFIG_BLOCK
1014 		err = -EINVAL;
1015 		if (!sb_set_blocksize(sb, d.blksize))
1016 			goto err;
1017 #endif
1018 	} else {
1019 		sb->s_blocksize = PAGE_CACHE_SIZE;
1020 		sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1021 	}
1022 	sb->s_magic = FUSE_SUPER_MAGIC;
1023 	sb->s_op = &fuse_super_operations;
1024 	sb->s_maxbytes = MAX_LFS_FILESIZE;
1025 	sb->s_time_gran = 1;
1026 	sb->s_export_op = &fuse_export_operations;
1027 
1028 	file = fget(d.fd);
1029 	err = -EINVAL;
1030 	if (!file)
1031 		goto err;
1032 
1033 	if ((file->f_op != &fuse_dev_operations) ||
1034 	    (file->f_cred->user_ns != &init_user_ns))
1035 		goto err_fput;
1036 
1037 	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1038 	err = -ENOMEM;
1039 	if (!fc)
1040 		goto err_fput;
1041 
1042 	fuse_conn_init(fc);
1043 
1044 	fc->dev = sb->s_dev;
1045 	fc->sb = sb;
1046 	err = fuse_bdi_init(fc, sb);
1047 	if (err)
1048 		goto err_put_conn;
1049 
1050 	sb->s_bdi = &fc->bdi;
1051 
1052 	/* Handle umasking inside the fuse code */
1053 	if (sb->s_flags & MS_POSIXACL)
1054 		fc->dont_mask = 1;
1055 	sb->s_flags |= MS_POSIXACL;
1056 
1057 	fc->release = fuse_free_conn;
1058 	fc->flags = d.flags;
1059 	fc->user_id = d.user_id;
1060 	fc->group_id = d.group_id;
1061 	fc->max_read = max_t(unsigned, 4096, d.max_read);
1062 
1063 	/* Used by get_root_inode() */
1064 	sb->s_fs_info = fc;
1065 
1066 	err = -ENOMEM;
1067 	root = fuse_get_root_inode(sb, d.rootmode);
1068 	root_dentry = d_make_root(root);
1069 	if (!root_dentry)
1070 		goto err_put_conn;
1071 	/* only now - we want root dentry with NULL ->d_op */
1072 	sb->s_d_op = &fuse_dentry_operations;
1073 
1074 	init_req = fuse_request_alloc(0);
1075 	if (!init_req)
1076 		goto err_put_root;
1077 	init_req->background = 1;
1078 
1079 	if (is_bdev) {
1080 		fc->destroy_req = fuse_request_alloc(0);
1081 		if (!fc->destroy_req)
1082 			goto err_free_init_req;
1083 	}
1084 
1085 	mutex_lock(&fuse_mutex);
1086 	err = -EINVAL;
1087 	if (file->private_data)
1088 		goto err_unlock;
1089 
1090 	err = fuse_ctl_add_conn(fc);
1091 	if (err)
1092 		goto err_unlock;
1093 
1094 	list_add_tail(&fc->entry, &fuse_conn_list);
1095 	sb->s_root = root_dentry;
1096 	fc->connected = 1;
1097 	file->private_data = fuse_conn_get(fc);
1098 	mutex_unlock(&fuse_mutex);
1099 	/*
1100 	 * atomic_dec_and_test() in fput() provides the necessary
1101 	 * memory barrier for file->private_data to be visible on all
1102 	 * CPUs after this
1103 	 */
1104 	fput(file);
1105 
1106 	fuse_send_init(fc, init_req);
1107 
1108 	return 0;
1109 
1110  err_unlock:
1111 	mutex_unlock(&fuse_mutex);
1112  err_free_init_req:
1113 	fuse_request_free(init_req);
1114  err_put_root:
1115 	dput(root_dentry);
1116  err_put_conn:
1117 	fuse_bdi_destroy(fc);
1118 	fuse_conn_put(fc);
1119  err_fput:
1120 	fput(file);
1121  err:
1122 	return err;
1123 }
1124 
1125 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1126 		       int flags, const char *dev_name,
1127 		       void *raw_data)
1128 {
1129 	return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1130 }
1131 
1132 static void fuse_kill_sb_anon(struct super_block *sb)
1133 {
1134 	struct fuse_conn *fc = get_fuse_conn_super(sb);
1135 
1136 	if (fc) {
1137 		down_write(&fc->killsb);
1138 		fc->sb = NULL;
1139 		up_write(&fc->killsb);
1140 	}
1141 
1142 	kill_anon_super(sb);
1143 }
1144 
1145 static struct file_system_type fuse_fs_type = {
1146 	.owner		= THIS_MODULE,
1147 	.name		= "fuse",
1148 	.fs_flags	= FS_HAS_SUBTYPE,
1149 	.mount		= fuse_mount,
1150 	.kill_sb	= fuse_kill_sb_anon,
1151 };
1152 MODULE_ALIAS_FS("fuse");
1153 
1154 #ifdef CONFIG_BLOCK
1155 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1156 			   int flags, const char *dev_name,
1157 			   void *raw_data)
1158 {
1159 	return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1160 }
1161 
1162 static void fuse_kill_sb_blk(struct super_block *sb)
1163 {
1164 	struct fuse_conn *fc = get_fuse_conn_super(sb);
1165 
1166 	if (fc) {
1167 		down_write(&fc->killsb);
1168 		fc->sb = NULL;
1169 		up_write(&fc->killsb);
1170 	}
1171 
1172 	kill_block_super(sb);
1173 }
1174 
1175 static struct file_system_type fuseblk_fs_type = {
1176 	.owner		= THIS_MODULE,
1177 	.name		= "fuseblk",
1178 	.mount		= fuse_mount_blk,
1179 	.kill_sb	= fuse_kill_sb_blk,
1180 	.fs_flags	= FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1181 };
1182 MODULE_ALIAS_FS("fuseblk");
1183 
1184 static inline int register_fuseblk(void)
1185 {
1186 	return register_filesystem(&fuseblk_fs_type);
1187 }
1188 
1189 static inline void unregister_fuseblk(void)
1190 {
1191 	unregister_filesystem(&fuseblk_fs_type);
1192 }
1193 #else
1194 static inline int register_fuseblk(void)
1195 {
1196 	return 0;
1197 }
1198 
1199 static inline void unregister_fuseblk(void)
1200 {
1201 }
1202 #endif
1203 
1204 static void fuse_inode_init_once(void *foo)
1205 {
1206 	struct inode *inode = foo;
1207 
1208 	inode_init_once(inode);
1209 }
1210 
1211 static int __init fuse_fs_init(void)
1212 {
1213 	int err;
1214 
1215 	fuse_inode_cachep = kmem_cache_create("fuse_inode",
1216 					      sizeof(struct fuse_inode),
1217 					      0, SLAB_HWCACHE_ALIGN,
1218 					      fuse_inode_init_once);
1219 	err = -ENOMEM;
1220 	if (!fuse_inode_cachep)
1221 		goto out;
1222 
1223 	err = register_fuseblk();
1224 	if (err)
1225 		goto out2;
1226 
1227 	err = register_filesystem(&fuse_fs_type);
1228 	if (err)
1229 		goto out3;
1230 
1231 	return 0;
1232 
1233  out3:
1234 	unregister_fuseblk();
1235  out2:
1236 	kmem_cache_destroy(fuse_inode_cachep);
1237  out:
1238 	return err;
1239 }
1240 
1241 static void fuse_fs_cleanup(void)
1242 {
1243 	unregister_filesystem(&fuse_fs_type);
1244 	unregister_fuseblk();
1245 
1246 	/*
1247 	 * Make sure all delayed rcu free inodes are flushed before we
1248 	 * destroy cache.
1249 	 */
1250 	rcu_barrier();
1251 	kmem_cache_destroy(fuse_inode_cachep);
1252 }
1253 
1254 static struct kobject *fuse_kobj;
1255 static struct kobject *connections_kobj;
1256 
1257 static int fuse_sysfs_init(void)
1258 {
1259 	int err;
1260 
1261 	fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1262 	if (!fuse_kobj) {
1263 		err = -ENOMEM;
1264 		goto out_err;
1265 	}
1266 
1267 	connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1268 	if (!connections_kobj) {
1269 		err = -ENOMEM;
1270 		goto out_fuse_unregister;
1271 	}
1272 
1273 	return 0;
1274 
1275  out_fuse_unregister:
1276 	kobject_put(fuse_kobj);
1277  out_err:
1278 	return err;
1279 }
1280 
1281 static void fuse_sysfs_cleanup(void)
1282 {
1283 	kobject_put(connections_kobj);
1284 	kobject_put(fuse_kobj);
1285 }
1286 
1287 static int __init fuse_init(void)
1288 {
1289 	int res;
1290 
1291 	printk(KERN_INFO "fuse init (API version %i.%i)\n",
1292 	       FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1293 
1294 	INIT_LIST_HEAD(&fuse_conn_list);
1295 	res = fuse_fs_init();
1296 	if (res)
1297 		goto err;
1298 
1299 	res = fuse_dev_init();
1300 	if (res)
1301 		goto err_fs_cleanup;
1302 
1303 	res = fuse_sysfs_init();
1304 	if (res)
1305 		goto err_dev_cleanup;
1306 
1307 	res = fuse_ctl_init();
1308 	if (res)
1309 		goto err_sysfs_cleanup;
1310 
1311 	sanitize_global_limit(&max_user_bgreq);
1312 	sanitize_global_limit(&max_user_congthresh);
1313 
1314 	return 0;
1315 
1316  err_sysfs_cleanup:
1317 	fuse_sysfs_cleanup();
1318  err_dev_cleanup:
1319 	fuse_dev_cleanup();
1320  err_fs_cleanup:
1321 	fuse_fs_cleanup();
1322  err:
1323 	return res;
1324 }
1325 
1326 static void __exit fuse_exit(void)
1327 {
1328 	printk(KERN_DEBUG "fuse exit\n");
1329 
1330 	fuse_ctl_cleanup();
1331 	fuse_sysfs_cleanup();
1332 	fuse_fs_cleanup();
1333 	fuse_dev_cleanup();
1334 }
1335 
1336 module_init(fuse_init);
1337 module_exit(fuse_exit);
1338