xref: /linux/fs/fuse/inode.c (revision eb2bce7f5e7ac1ca6da434461217fadf3c688d2c)
1 /*
2   FUSE: Filesystem in Userspace
3   Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
4 
5   This program can be distributed under the terms of the GNU GPL.
6   See the file COPYING.
7 */
8 
9 #include "fuse_i.h"
10 
11 #include <linux/pagemap.h>
12 #include <linux/slab.h>
13 #include <linux/file.h>
14 #include <linux/seq_file.h>
15 #include <linux/init.h>
16 #include <linux/module.h>
17 #include <linux/parser.h>
18 #include <linux/statfs.h>
19 #include <linux/random.h>
20 
21 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
22 MODULE_DESCRIPTION("Filesystem in Userspace");
23 MODULE_LICENSE("GPL");
24 
25 static struct kmem_cache *fuse_inode_cachep;
26 struct list_head fuse_conn_list;
27 DEFINE_MUTEX(fuse_mutex);
28 
29 #define FUSE_SUPER_MAGIC 0x65735546
30 
31 struct fuse_mount_data {
32 	int fd;
33 	unsigned rootmode;
34 	unsigned user_id;
35 	unsigned group_id;
36 	unsigned fd_present : 1;
37 	unsigned rootmode_present : 1;
38 	unsigned user_id_present : 1;
39 	unsigned group_id_present : 1;
40 	unsigned flags;
41 	unsigned max_read;
42 	unsigned blksize;
43 };
44 
45 static struct inode *fuse_alloc_inode(struct super_block *sb)
46 {
47 	struct inode *inode;
48 	struct fuse_inode *fi;
49 
50 	inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
51 	if (!inode)
52 		return NULL;
53 
54 	fi = get_fuse_inode(inode);
55 	fi->i_time = 0;
56 	fi->nodeid = 0;
57 	fi->nlookup = 0;
58 	fi->forget_req = fuse_request_alloc();
59 	if (!fi->forget_req) {
60 		kmem_cache_free(fuse_inode_cachep, inode);
61 		return NULL;
62 	}
63 
64 	return inode;
65 }
66 
67 static void fuse_destroy_inode(struct inode *inode)
68 {
69 	struct fuse_inode *fi = get_fuse_inode(inode);
70 	if (fi->forget_req)
71 		fuse_request_free(fi->forget_req);
72 	kmem_cache_free(fuse_inode_cachep, inode);
73 }
74 
75 static void fuse_read_inode(struct inode *inode)
76 {
77 	/* No op */
78 }
79 
80 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
81 		      unsigned long nodeid, u64 nlookup)
82 {
83 	struct fuse_forget_in *inarg = &req->misc.forget_in;
84 	inarg->nlookup = nlookup;
85 	req->in.h.opcode = FUSE_FORGET;
86 	req->in.h.nodeid = nodeid;
87 	req->in.numargs = 1;
88 	req->in.args[0].size = sizeof(struct fuse_forget_in);
89 	req->in.args[0].value = inarg;
90 	request_send_noreply(fc, req);
91 }
92 
93 static void fuse_clear_inode(struct inode *inode)
94 {
95 	if (inode->i_sb->s_flags & MS_ACTIVE) {
96 		struct fuse_conn *fc = get_fuse_conn(inode);
97 		struct fuse_inode *fi = get_fuse_inode(inode);
98 		fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
99 		fi->forget_req = NULL;
100 	}
101 }
102 
103 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
104 {
105 	if (*flags & MS_MANDLOCK)
106 		return -EINVAL;
107 
108 	return 0;
109 }
110 
111 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
112 {
113 	struct fuse_conn *fc = get_fuse_conn(inode);
114 	if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
115 		invalidate_mapping_pages(inode->i_mapping, 0, -1);
116 
117 	inode->i_ino     = attr->ino;
118 	inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
119 	inode->i_nlink   = attr->nlink;
120 	inode->i_uid     = attr->uid;
121 	inode->i_gid     = attr->gid;
122 	spin_lock(&fc->lock);
123 	i_size_write(inode, attr->size);
124 	spin_unlock(&fc->lock);
125 	inode->i_blocks  = attr->blocks;
126 	inode->i_atime.tv_sec   = attr->atime;
127 	inode->i_atime.tv_nsec  = attr->atimensec;
128 	inode->i_mtime.tv_sec   = attr->mtime;
129 	inode->i_mtime.tv_nsec  = attr->mtimensec;
130 	inode->i_ctime.tv_sec   = attr->ctime;
131 	inode->i_ctime.tv_nsec  = attr->ctimensec;
132 }
133 
134 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
135 {
136 	inode->i_mode = attr->mode & S_IFMT;
137 	inode->i_size = attr->size;
138 	if (S_ISREG(inode->i_mode)) {
139 		fuse_init_common(inode);
140 		fuse_init_file_inode(inode);
141 	} else if (S_ISDIR(inode->i_mode))
142 		fuse_init_dir(inode);
143 	else if (S_ISLNK(inode->i_mode))
144 		fuse_init_symlink(inode);
145 	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
146 		 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
147 		fuse_init_common(inode);
148 		init_special_inode(inode, inode->i_mode,
149 				   new_decode_dev(attr->rdev));
150 	} else
151 		BUG();
152 }
153 
154 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
155 {
156 	unsigned long nodeid = *(unsigned long *) _nodeidp;
157 	if (get_node_id(inode) == nodeid)
158 		return 1;
159 	else
160 		return 0;
161 }
162 
163 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
164 {
165 	unsigned long nodeid = *(unsigned long *) _nodeidp;
166 	get_fuse_inode(inode)->nodeid = nodeid;
167 	return 0;
168 }
169 
170 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
171 			int generation, struct fuse_attr *attr)
172 {
173 	struct inode *inode;
174 	struct fuse_inode *fi;
175 	struct fuse_conn *fc = get_fuse_conn_super(sb);
176 
177  retry:
178 	inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
179 	if (!inode)
180 		return NULL;
181 
182 	if ((inode->i_state & I_NEW)) {
183 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
184 		inode->i_generation = generation;
185 		inode->i_data.backing_dev_info = &fc->bdi;
186 		fuse_init_inode(inode, attr);
187 		unlock_new_inode(inode);
188 	} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
189 		/* Inode has changed type, any I/O on the old should fail */
190 		make_bad_inode(inode);
191 		iput(inode);
192 		goto retry;
193 	}
194 
195 	fi = get_fuse_inode(inode);
196 	spin_lock(&fc->lock);
197 	fi->nlookup ++;
198 	spin_unlock(&fc->lock);
199 	fuse_change_attributes(inode, attr);
200 	return inode;
201 }
202 
203 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
204 {
205 	if (flags & MNT_FORCE)
206 		fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
207 }
208 
209 static void fuse_send_destroy(struct fuse_conn *fc)
210 {
211 	struct fuse_req *req = fc->destroy_req;
212 	if (req && fc->conn_init) {
213 		fc->destroy_req = NULL;
214 		req->in.h.opcode = FUSE_DESTROY;
215 		req->force = 1;
216 		request_send(fc, req);
217 		fuse_put_request(fc, req);
218 	}
219 }
220 
221 static void fuse_put_super(struct super_block *sb)
222 {
223 	struct fuse_conn *fc = get_fuse_conn_super(sb);
224 
225 	fuse_send_destroy(fc);
226 	spin_lock(&fc->lock);
227 	fc->connected = 0;
228 	fc->blocked = 0;
229 	spin_unlock(&fc->lock);
230 	/* Flush all readers on this fs */
231 	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
232 	wake_up_all(&fc->waitq);
233 	wake_up_all(&fc->blocked_waitq);
234 	mutex_lock(&fuse_mutex);
235 	list_del(&fc->entry);
236 	fuse_ctl_remove_conn(fc);
237 	mutex_unlock(&fuse_mutex);
238 	fuse_conn_put(fc);
239 }
240 
241 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
242 {
243 	stbuf->f_type    = FUSE_SUPER_MAGIC;
244 	stbuf->f_bsize   = attr->bsize;
245 	stbuf->f_frsize  = attr->frsize;
246 	stbuf->f_blocks  = attr->blocks;
247 	stbuf->f_bfree   = attr->bfree;
248 	stbuf->f_bavail  = attr->bavail;
249 	stbuf->f_files   = attr->files;
250 	stbuf->f_ffree   = attr->ffree;
251 	stbuf->f_namelen = attr->namelen;
252 	/* fsid is left zero */
253 }
254 
255 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
256 {
257 	struct super_block *sb = dentry->d_sb;
258 	struct fuse_conn *fc = get_fuse_conn_super(sb);
259 	struct fuse_req *req;
260 	struct fuse_statfs_out outarg;
261 	int err;
262 
263 	req = fuse_get_req(fc);
264 	if (IS_ERR(req))
265 		return PTR_ERR(req);
266 
267 	memset(&outarg, 0, sizeof(outarg));
268 	req->in.numargs = 0;
269 	req->in.h.opcode = FUSE_STATFS;
270 	req->in.h.nodeid = get_node_id(dentry->d_inode);
271 	req->out.numargs = 1;
272 	req->out.args[0].size =
273 		fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
274 	req->out.args[0].value = &outarg;
275 	request_send(fc, req);
276 	err = req->out.h.error;
277 	if (!err)
278 		convert_fuse_statfs(buf, &outarg.st);
279 	fuse_put_request(fc, req);
280 	return err;
281 }
282 
283 enum {
284 	OPT_FD,
285 	OPT_ROOTMODE,
286 	OPT_USER_ID,
287 	OPT_GROUP_ID,
288 	OPT_DEFAULT_PERMISSIONS,
289 	OPT_ALLOW_OTHER,
290 	OPT_MAX_READ,
291 	OPT_BLKSIZE,
292 	OPT_ERR
293 };
294 
295 static match_table_t tokens = {
296 	{OPT_FD,			"fd=%u"},
297 	{OPT_ROOTMODE,			"rootmode=%o"},
298 	{OPT_USER_ID,			"user_id=%u"},
299 	{OPT_GROUP_ID,			"group_id=%u"},
300 	{OPT_DEFAULT_PERMISSIONS,	"default_permissions"},
301 	{OPT_ALLOW_OTHER,		"allow_other"},
302 	{OPT_MAX_READ,			"max_read=%u"},
303 	{OPT_BLKSIZE,			"blksize=%u"},
304 	{OPT_ERR,			NULL}
305 };
306 
307 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
308 {
309 	char *p;
310 	memset(d, 0, sizeof(struct fuse_mount_data));
311 	d->max_read = ~0;
312 	d->blksize = 512;
313 
314 	while ((p = strsep(&opt, ",")) != NULL) {
315 		int token;
316 		int value;
317 		substring_t args[MAX_OPT_ARGS];
318 		if (!*p)
319 			continue;
320 
321 		token = match_token(p, tokens, args);
322 		switch (token) {
323 		case OPT_FD:
324 			if (match_int(&args[0], &value))
325 				return 0;
326 			d->fd = value;
327 			d->fd_present = 1;
328 			break;
329 
330 		case OPT_ROOTMODE:
331 			if (match_octal(&args[0], &value))
332 				return 0;
333 			if (!fuse_valid_type(value))
334 				return 0;
335 			d->rootmode = value;
336 			d->rootmode_present = 1;
337 			break;
338 
339 		case OPT_USER_ID:
340 			if (match_int(&args[0], &value))
341 				return 0;
342 			d->user_id = value;
343 			d->user_id_present = 1;
344 			break;
345 
346 		case OPT_GROUP_ID:
347 			if (match_int(&args[0], &value))
348 				return 0;
349 			d->group_id = value;
350 			d->group_id_present = 1;
351 			break;
352 
353 		case OPT_DEFAULT_PERMISSIONS:
354 			d->flags |= FUSE_DEFAULT_PERMISSIONS;
355 			break;
356 
357 		case OPT_ALLOW_OTHER:
358 			d->flags |= FUSE_ALLOW_OTHER;
359 			break;
360 
361 		case OPT_MAX_READ:
362 			if (match_int(&args[0], &value))
363 				return 0;
364 			d->max_read = value;
365 			break;
366 
367 		case OPT_BLKSIZE:
368 			if (!is_bdev || match_int(&args[0], &value))
369 				return 0;
370 			d->blksize = value;
371 			break;
372 
373 		default:
374 			return 0;
375 		}
376 	}
377 
378 	if (!d->fd_present || !d->rootmode_present ||
379 	    !d->user_id_present || !d->group_id_present)
380 		return 0;
381 
382 	return 1;
383 }
384 
385 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
386 {
387 	struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
388 
389 	seq_printf(m, ",user_id=%u", fc->user_id);
390 	seq_printf(m, ",group_id=%u", fc->group_id);
391 	if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
392 		seq_puts(m, ",default_permissions");
393 	if (fc->flags & FUSE_ALLOW_OTHER)
394 		seq_puts(m, ",allow_other");
395 	if (fc->max_read != ~0)
396 		seq_printf(m, ",max_read=%u", fc->max_read);
397 	return 0;
398 }
399 
400 static struct fuse_conn *new_conn(void)
401 {
402 	struct fuse_conn *fc;
403 
404 	fc = kzalloc(sizeof(*fc), GFP_KERNEL);
405 	if (fc) {
406 		spin_lock_init(&fc->lock);
407 		mutex_init(&fc->inst_mutex);
408 		atomic_set(&fc->count, 1);
409 		init_waitqueue_head(&fc->waitq);
410 		init_waitqueue_head(&fc->blocked_waitq);
411 		INIT_LIST_HEAD(&fc->pending);
412 		INIT_LIST_HEAD(&fc->processing);
413 		INIT_LIST_HEAD(&fc->io);
414 		INIT_LIST_HEAD(&fc->interrupts);
415 		atomic_set(&fc->num_waiting, 0);
416 		fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
417 		fc->bdi.unplug_io_fn = default_unplug_io_fn;
418 		fc->reqctr = 0;
419 		fc->blocked = 1;
420 		get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
421 	}
422 	return fc;
423 }
424 
425 void fuse_conn_put(struct fuse_conn *fc)
426 {
427 	if (atomic_dec_and_test(&fc->count)) {
428 		if (fc->destroy_req)
429 			fuse_request_free(fc->destroy_req);
430 		mutex_destroy(&fc->inst_mutex);
431 		kfree(fc);
432 	}
433 }
434 
435 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
436 {
437 	atomic_inc(&fc->count);
438 	return fc;
439 }
440 
441 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
442 {
443 	struct fuse_attr attr;
444 	memset(&attr, 0, sizeof(attr));
445 
446 	attr.mode = mode;
447 	attr.ino = FUSE_ROOT_ID;
448 	return fuse_iget(sb, 1, 0, &attr);
449 }
450 
451 static const struct super_operations fuse_super_operations = {
452 	.alloc_inode    = fuse_alloc_inode,
453 	.destroy_inode  = fuse_destroy_inode,
454 	.read_inode	= fuse_read_inode,
455 	.clear_inode	= fuse_clear_inode,
456 	.remount_fs	= fuse_remount_fs,
457 	.put_super	= fuse_put_super,
458 	.umount_begin	= fuse_umount_begin,
459 	.statfs		= fuse_statfs,
460 	.show_options	= fuse_show_options,
461 };
462 
463 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
464 {
465 	struct fuse_init_out *arg = &req->misc.init_out;
466 
467 	if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
468 		fc->conn_error = 1;
469 	else {
470 		unsigned long ra_pages;
471 
472 		if (arg->minor >= 6) {
473 			ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
474 			if (arg->flags & FUSE_ASYNC_READ)
475 				fc->async_read = 1;
476 			if (!(arg->flags & FUSE_POSIX_LOCKS))
477 				fc->no_lock = 1;
478 		} else {
479 			ra_pages = fc->max_read / PAGE_CACHE_SIZE;
480 			fc->no_lock = 1;
481 		}
482 
483 		fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
484 		fc->minor = arg->minor;
485 		fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
486 		fc->conn_init = 1;
487 	}
488 	fuse_put_request(fc, req);
489 	fc->blocked = 0;
490 	wake_up_all(&fc->blocked_waitq);
491 }
492 
493 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
494 {
495 	struct fuse_init_in *arg = &req->misc.init_in;
496 
497 	arg->major = FUSE_KERNEL_VERSION;
498 	arg->minor = FUSE_KERNEL_MINOR_VERSION;
499 	arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
500 	arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
501 	req->in.h.opcode = FUSE_INIT;
502 	req->in.numargs = 1;
503 	req->in.args[0].size = sizeof(*arg);
504 	req->in.args[0].value = arg;
505 	req->out.numargs = 1;
506 	/* Variable length arguement used for backward compatibility
507 	   with interface version < 7.5.  Rest of init_out is zeroed
508 	   by do_get_request(), so a short reply is not a problem */
509 	req->out.argvar = 1;
510 	req->out.args[0].size = sizeof(struct fuse_init_out);
511 	req->out.args[0].value = &req->misc.init_out;
512 	req->end = process_init_reply;
513 	request_send_background(fc, req);
514 }
515 
516 static u64 conn_id(void)
517 {
518 	static u64 ctr = 1;
519 	return ctr++;
520 }
521 
522 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
523 {
524 	struct fuse_conn *fc;
525 	struct inode *root;
526 	struct fuse_mount_data d;
527 	struct file *file;
528 	struct dentry *root_dentry;
529 	struct fuse_req *init_req;
530 	int err;
531 	int is_bdev = sb->s_bdev != NULL;
532 
533 	if (sb->s_flags & MS_MANDLOCK)
534 		return -EINVAL;
535 
536 	if (!parse_fuse_opt((char *) data, &d, is_bdev))
537 		return -EINVAL;
538 
539 	if (is_bdev) {
540 #ifdef CONFIG_BLOCK
541 		if (!sb_set_blocksize(sb, d.blksize))
542 			return -EINVAL;
543 #endif
544 	} else {
545 		sb->s_blocksize = PAGE_CACHE_SIZE;
546 		sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
547 	}
548 	sb->s_magic = FUSE_SUPER_MAGIC;
549 	sb->s_op = &fuse_super_operations;
550 	sb->s_maxbytes = MAX_LFS_FILESIZE;
551 
552 	file = fget(d.fd);
553 	if (!file)
554 		return -EINVAL;
555 
556 	if (file->f_op != &fuse_dev_operations)
557 		return -EINVAL;
558 
559 	fc = new_conn();
560 	if (!fc)
561 		return -ENOMEM;
562 
563 	fc->flags = d.flags;
564 	fc->user_id = d.user_id;
565 	fc->group_id = d.group_id;
566 	fc->max_read = d.max_read;
567 
568 	/* Used by get_root_inode() */
569 	sb->s_fs_info = fc;
570 
571 	err = -ENOMEM;
572 	root = get_root_inode(sb, d.rootmode);
573 	if (!root)
574 		goto err;
575 
576 	root_dentry = d_alloc_root(root);
577 	if (!root_dentry) {
578 		iput(root);
579 		goto err;
580 	}
581 
582 	init_req = fuse_request_alloc();
583 	if (!init_req)
584 		goto err_put_root;
585 
586 	if (is_bdev) {
587 		fc->destroy_req = fuse_request_alloc();
588 		if (!fc->destroy_req)
589 			goto err_put_root;
590 	}
591 
592 	mutex_lock(&fuse_mutex);
593 	err = -EINVAL;
594 	if (file->private_data)
595 		goto err_unlock;
596 
597 	fc->id = conn_id();
598 	err = fuse_ctl_add_conn(fc);
599 	if (err)
600 		goto err_unlock;
601 
602 	list_add_tail(&fc->entry, &fuse_conn_list);
603 	sb->s_root = root_dentry;
604 	fc->connected = 1;
605 	file->private_data = fuse_conn_get(fc);
606 	mutex_unlock(&fuse_mutex);
607 	/*
608 	 * atomic_dec_and_test() in fput() provides the necessary
609 	 * memory barrier for file->private_data to be visible on all
610 	 * CPUs after this
611 	 */
612 	fput(file);
613 
614 	fuse_send_init(fc, init_req);
615 
616 	return 0;
617 
618  err_unlock:
619 	mutex_unlock(&fuse_mutex);
620 	fuse_request_free(init_req);
621  err_put_root:
622 	dput(root_dentry);
623  err:
624 	fput(file);
625 	fuse_conn_put(fc);
626 	return err;
627 }
628 
629 static int fuse_get_sb(struct file_system_type *fs_type,
630 		       int flags, const char *dev_name,
631 		       void *raw_data, struct vfsmount *mnt)
632 {
633 	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
634 }
635 
636 static struct file_system_type fuse_fs_type = {
637 	.owner		= THIS_MODULE,
638 	.name		= "fuse",
639 	.get_sb		= fuse_get_sb,
640 	.kill_sb	= kill_anon_super,
641 };
642 
643 #ifdef CONFIG_BLOCK
644 static int fuse_get_sb_blk(struct file_system_type *fs_type,
645 			   int flags, const char *dev_name,
646 			   void *raw_data, struct vfsmount *mnt)
647 {
648 	return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
649 			   mnt);
650 }
651 
652 static struct file_system_type fuseblk_fs_type = {
653 	.owner		= THIS_MODULE,
654 	.name		= "fuseblk",
655 	.get_sb		= fuse_get_sb_blk,
656 	.kill_sb	= kill_block_super,
657 	.fs_flags	= FS_REQUIRES_DEV,
658 };
659 
660 static inline int register_fuseblk(void)
661 {
662 	return register_filesystem(&fuseblk_fs_type);
663 }
664 
665 static inline void unregister_fuseblk(void)
666 {
667 	unregister_filesystem(&fuseblk_fs_type);
668 }
669 #else
670 static inline int register_fuseblk(void)
671 {
672 	return 0;
673 }
674 
675 static inline void unregister_fuseblk(void)
676 {
677 }
678 #endif
679 
680 static decl_subsys(fuse, NULL, NULL);
681 static decl_subsys(connections, NULL, NULL);
682 
683 static void fuse_inode_init_once(void *foo, struct kmem_cache *cachep,
684 				 unsigned long flags)
685 {
686 	struct inode * inode = foo;
687 
688 	if (flags & SLAB_CTOR_CONSTRUCTOR)
689 		inode_init_once(inode);
690 }
691 
692 static int __init fuse_fs_init(void)
693 {
694 	int err;
695 
696 	err = register_filesystem(&fuse_fs_type);
697 	if (err)
698 		goto out;
699 
700 	err = register_fuseblk();
701 	if (err)
702 		goto out_unreg;
703 
704 	fuse_inode_cachep = kmem_cache_create("fuse_inode",
705 					      sizeof(struct fuse_inode),
706 					      0, SLAB_HWCACHE_ALIGN,
707 					      fuse_inode_init_once, NULL);
708 	err = -ENOMEM;
709 	if (!fuse_inode_cachep)
710 		goto out_unreg2;
711 
712 	return 0;
713 
714  out_unreg2:
715 	unregister_fuseblk();
716  out_unreg:
717 	unregister_filesystem(&fuse_fs_type);
718  out:
719 	return err;
720 }
721 
722 static void fuse_fs_cleanup(void)
723 {
724 	unregister_filesystem(&fuse_fs_type);
725 	unregister_fuseblk();
726 	kmem_cache_destroy(fuse_inode_cachep);
727 }
728 
729 static int fuse_sysfs_init(void)
730 {
731 	int err;
732 
733 	kobj_set_kset_s(&fuse_subsys, fs_subsys);
734 	err = subsystem_register(&fuse_subsys);
735 	if (err)
736 		goto out_err;
737 
738 	kobj_set_kset_s(&connections_subsys, fuse_subsys);
739 	err = subsystem_register(&connections_subsys);
740 	if (err)
741 		goto out_fuse_unregister;
742 
743 	return 0;
744 
745  out_fuse_unregister:
746 	subsystem_unregister(&fuse_subsys);
747  out_err:
748 	return err;
749 }
750 
751 static void fuse_sysfs_cleanup(void)
752 {
753 	subsystem_unregister(&connections_subsys);
754 	subsystem_unregister(&fuse_subsys);
755 }
756 
757 static int __init fuse_init(void)
758 {
759 	int res;
760 
761 	printk("fuse init (API version %i.%i)\n",
762 	       FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
763 
764 	INIT_LIST_HEAD(&fuse_conn_list);
765 	res = fuse_fs_init();
766 	if (res)
767 		goto err;
768 
769 	res = fuse_dev_init();
770 	if (res)
771 		goto err_fs_cleanup;
772 
773 	res = fuse_sysfs_init();
774 	if (res)
775 		goto err_dev_cleanup;
776 
777 	res = fuse_ctl_init();
778 	if (res)
779 		goto err_sysfs_cleanup;
780 
781 	return 0;
782 
783  err_sysfs_cleanup:
784 	fuse_sysfs_cleanup();
785  err_dev_cleanup:
786 	fuse_dev_cleanup();
787  err_fs_cleanup:
788 	fuse_fs_cleanup();
789  err:
790 	return res;
791 }
792 
793 static void __exit fuse_exit(void)
794 {
795 	printk(KERN_DEBUG "fuse exit\n");
796 
797 	fuse_ctl_cleanup();
798 	fuse_sysfs_cleanup();
799 	fuse_fs_cleanup();
800 	fuse_dev_cleanup();
801 }
802 
803 module_init(fuse_init);
804 module_exit(fuse_exit);
805