xref: /openbmc/linux/fs/fuse/inode.c (revision c21b37f6)
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 #include <linux/sched.h>
21 
22 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
23 MODULE_DESCRIPTION("Filesystem in Userspace");
24 MODULE_LICENSE("GPL");
25 
26 static struct kmem_cache *fuse_inode_cachep;
27 struct list_head fuse_conn_list;
28 DEFINE_MUTEX(fuse_mutex);
29 
30 #define FUSE_SUPER_MAGIC 0x65735546
31 
32 struct fuse_mount_data {
33 	int fd;
34 	unsigned rootmode;
35 	unsigned user_id;
36 	unsigned group_id;
37 	unsigned fd_present : 1;
38 	unsigned rootmode_present : 1;
39 	unsigned user_id_present : 1;
40 	unsigned group_id_present : 1;
41 	unsigned flags;
42 	unsigned max_read;
43 	unsigned blksize;
44 };
45 
46 static struct inode *fuse_alloc_inode(struct super_block *sb)
47 {
48 	struct inode *inode;
49 	struct fuse_inode *fi;
50 
51 	inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
52 	if (!inode)
53 		return NULL;
54 
55 	fi = get_fuse_inode(inode);
56 	fi->i_time = 0;
57 	fi->nodeid = 0;
58 	fi->nlookup = 0;
59 	fi->forget_req = fuse_request_alloc();
60 	if (!fi->forget_req) {
61 		kmem_cache_free(fuse_inode_cachep, inode);
62 		return NULL;
63 	}
64 
65 	return inode;
66 }
67 
68 static void fuse_destroy_inode(struct inode *inode)
69 {
70 	struct fuse_inode *fi = get_fuse_inode(inode);
71 	if (fi->forget_req)
72 		fuse_request_free(fi->forget_req);
73 	kmem_cache_free(fuse_inode_cachep, inode);
74 }
75 
76 static void fuse_read_inode(struct inode *inode)
77 {
78 	/* No op */
79 }
80 
81 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
82 		      unsigned long nodeid, u64 nlookup)
83 {
84 	struct fuse_forget_in *inarg = &req->misc.forget_in;
85 	inarg->nlookup = nlookup;
86 	req->in.h.opcode = FUSE_FORGET;
87 	req->in.h.nodeid = nodeid;
88 	req->in.numargs = 1;
89 	req->in.args[0].size = sizeof(struct fuse_forget_in);
90 	req->in.args[0].value = inarg;
91 	request_send_noreply(fc, req);
92 }
93 
94 static void fuse_clear_inode(struct inode *inode)
95 {
96 	if (inode->i_sb->s_flags & MS_ACTIVE) {
97 		struct fuse_conn *fc = get_fuse_conn(inode);
98 		struct fuse_inode *fi = get_fuse_inode(inode);
99 		fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
100 		fi->forget_req = NULL;
101 	}
102 }
103 
104 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
105 {
106 	if (*flags & MS_MANDLOCK)
107 		return -EINVAL;
108 
109 	return 0;
110 }
111 
112 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
113 {
114 	struct fuse_conn *fc = get_fuse_conn(inode);
115 	if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
116 		invalidate_mapping_pages(inode->i_mapping, 0, -1);
117 
118 	inode->i_ino     = attr->ino;
119 	inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
120 	inode->i_nlink   = attr->nlink;
121 	inode->i_uid     = attr->uid;
122 	inode->i_gid     = attr->gid;
123 	spin_lock(&fc->lock);
124 	i_size_write(inode, attr->size);
125 	spin_unlock(&fc->lock);
126 	inode->i_blocks  = attr->blocks;
127 	inode->i_atime.tv_sec   = attr->atime;
128 	inode->i_atime.tv_nsec  = attr->atimensec;
129 	inode->i_mtime.tv_sec   = attr->mtime;
130 	inode->i_mtime.tv_nsec  = attr->mtimensec;
131 	inode->i_ctime.tv_sec   = attr->ctime;
132 	inode->i_ctime.tv_nsec  = attr->ctimensec;
133 }
134 
135 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
136 {
137 	inode->i_mode = attr->mode & S_IFMT;
138 	inode->i_size = attr->size;
139 	if (S_ISREG(inode->i_mode)) {
140 		fuse_init_common(inode);
141 		fuse_init_file_inode(inode);
142 	} else if (S_ISDIR(inode->i_mode))
143 		fuse_init_dir(inode);
144 	else if (S_ISLNK(inode->i_mode))
145 		fuse_init_symlink(inode);
146 	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
147 		 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
148 		fuse_init_common(inode);
149 		init_special_inode(inode, inode->i_mode,
150 				   new_decode_dev(attr->rdev));
151 	} else
152 		BUG();
153 }
154 
155 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
156 {
157 	unsigned long nodeid = *(unsigned long *) _nodeidp;
158 	if (get_node_id(inode) == nodeid)
159 		return 1;
160 	else
161 		return 0;
162 }
163 
164 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
165 {
166 	unsigned long nodeid = *(unsigned long *) _nodeidp;
167 	get_fuse_inode(inode)->nodeid = nodeid;
168 	return 0;
169 }
170 
171 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
172 			int generation, struct fuse_attr *attr)
173 {
174 	struct inode *inode;
175 	struct fuse_inode *fi;
176 	struct fuse_conn *fc = get_fuse_conn_super(sb);
177 
178  retry:
179 	inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
180 	if (!inode)
181 		return NULL;
182 
183 	if ((inode->i_state & I_NEW)) {
184 		inode->i_flags |= S_NOATIME|S_NOCMTIME;
185 		inode->i_generation = generation;
186 		inode->i_data.backing_dev_info = &fc->bdi;
187 		fuse_init_inode(inode, attr);
188 		unlock_new_inode(inode);
189 	} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
190 		/* Inode has changed type, any I/O on the old should fail */
191 		make_bad_inode(inode);
192 		iput(inode);
193 		goto retry;
194 	}
195 
196 	fi = get_fuse_inode(inode);
197 	spin_lock(&fc->lock);
198 	fi->nlookup ++;
199 	spin_unlock(&fc->lock);
200 	fuse_change_attributes(inode, attr);
201 	return inode;
202 }
203 
204 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
205 {
206 	if (flags & MNT_FORCE)
207 		fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
208 }
209 
210 static void fuse_send_destroy(struct fuse_conn *fc)
211 {
212 	struct fuse_req *req = fc->destroy_req;
213 	if (req && fc->conn_init) {
214 		fc->destroy_req = NULL;
215 		req->in.h.opcode = FUSE_DESTROY;
216 		req->force = 1;
217 		request_send(fc, req);
218 		fuse_put_request(fc, req);
219 	}
220 }
221 
222 static void fuse_put_super(struct super_block *sb)
223 {
224 	struct fuse_conn *fc = get_fuse_conn_super(sb);
225 
226 	fuse_send_destroy(fc);
227 	spin_lock(&fc->lock);
228 	fc->connected = 0;
229 	fc->blocked = 0;
230 	spin_unlock(&fc->lock);
231 	/* Flush all readers on this fs */
232 	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
233 	wake_up_all(&fc->waitq);
234 	wake_up_all(&fc->blocked_waitq);
235 	mutex_lock(&fuse_mutex);
236 	list_del(&fc->entry);
237 	fuse_ctl_remove_conn(fc);
238 	mutex_unlock(&fuse_mutex);
239 	fuse_conn_put(fc);
240 }
241 
242 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
243 {
244 	stbuf->f_type    = FUSE_SUPER_MAGIC;
245 	stbuf->f_bsize   = attr->bsize;
246 	stbuf->f_frsize  = attr->frsize;
247 	stbuf->f_blocks  = attr->blocks;
248 	stbuf->f_bfree   = attr->bfree;
249 	stbuf->f_bavail  = attr->bavail;
250 	stbuf->f_files   = attr->files;
251 	stbuf->f_ffree   = attr->ffree;
252 	stbuf->f_namelen = attr->namelen;
253 	/* fsid is left zero */
254 }
255 
256 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
257 {
258 	struct super_block *sb = dentry->d_sb;
259 	struct fuse_conn *fc = get_fuse_conn_super(sb);
260 	struct fuse_req *req;
261 	struct fuse_statfs_out outarg;
262 	int err;
263 
264 	req = fuse_get_req(fc);
265 	if (IS_ERR(req))
266 		return PTR_ERR(req);
267 
268 	memset(&outarg, 0, sizeof(outarg));
269 	req->in.numargs = 0;
270 	req->in.h.opcode = FUSE_STATFS;
271 	req->in.h.nodeid = get_node_id(dentry->d_inode);
272 	req->out.numargs = 1;
273 	req->out.args[0].size =
274 		fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
275 	req->out.args[0].value = &outarg;
276 	request_send(fc, req);
277 	err = req->out.h.error;
278 	if (!err)
279 		convert_fuse_statfs(buf, &outarg.st);
280 	fuse_put_request(fc, req);
281 	return err;
282 }
283 
284 enum {
285 	OPT_FD,
286 	OPT_ROOTMODE,
287 	OPT_USER_ID,
288 	OPT_GROUP_ID,
289 	OPT_DEFAULT_PERMISSIONS,
290 	OPT_ALLOW_OTHER,
291 	OPT_MAX_READ,
292 	OPT_BLKSIZE,
293 	OPT_ERR
294 };
295 
296 static match_table_t tokens = {
297 	{OPT_FD,			"fd=%u"},
298 	{OPT_ROOTMODE,			"rootmode=%o"},
299 	{OPT_USER_ID,			"user_id=%u"},
300 	{OPT_GROUP_ID,			"group_id=%u"},
301 	{OPT_DEFAULT_PERMISSIONS,	"default_permissions"},
302 	{OPT_ALLOW_OTHER,		"allow_other"},
303 	{OPT_MAX_READ,			"max_read=%u"},
304 	{OPT_BLKSIZE,			"blksize=%u"},
305 	{OPT_ERR,			NULL}
306 };
307 
308 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
309 {
310 	char *p;
311 	memset(d, 0, sizeof(struct fuse_mount_data));
312 	d->max_read = ~0;
313 	d->blksize = 512;
314 
315 	while ((p = strsep(&opt, ",")) != NULL) {
316 		int token;
317 		int value;
318 		substring_t args[MAX_OPT_ARGS];
319 		if (!*p)
320 			continue;
321 
322 		token = match_token(p, tokens, args);
323 		switch (token) {
324 		case OPT_FD:
325 			if (match_int(&args[0], &value))
326 				return 0;
327 			d->fd = value;
328 			d->fd_present = 1;
329 			break;
330 
331 		case OPT_ROOTMODE:
332 			if (match_octal(&args[0], &value))
333 				return 0;
334 			if (!fuse_valid_type(value))
335 				return 0;
336 			d->rootmode = value;
337 			d->rootmode_present = 1;
338 			break;
339 
340 		case OPT_USER_ID:
341 			if (match_int(&args[0], &value))
342 				return 0;
343 			d->user_id = value;
344 			d->user_id_present = 1;
345 			break;
346 
347 		case OPT_GROUP_ID:
348 			if (match_int(&args[0], &value))
349 				return 0;
350 			d->group_id = value;
351 			d->group_id_present = 1;
352 			break;
353 
354 		case OPT_DEFAULT_PERMISSIONS:
355 			d->flags |= FUSE_DEFAULT_PERMISSIONS;
356 			break;
357 
358 		case OPT_ALLOW_OTHER:
359 			d->flags |= FUSE_ALLOW_OTHER;
360 			break;
361 
362 		case OPT_MAX_READ:
363 			if (match_int(&args[0], &value))
364 				return 0;
365 			d->max_read = value;
366 			break;
367 
368 		case OPT_BLKSIZE:
369 			if (!is_bdev || match_int(&args[0], &value))
370 				return 0;
371 			d->blksize = value;
372 			break;
373 
374 		default:
375 			return 0;
376 		}
377 	}
378 
379 	if (!d->fd_present || !d->rootmode_present ||
380 	    !d->user_id_present || !d->group_id_present)
381 		return 0;
382 
383 	return 1;
384 }
385 
386 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
387 {
388 	struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
389 
390 	seq_printf(m, ",user_id=%u", fc->user_id);
391 	seq_printf(m, ",group_id=%u", fc->group_id);
392 	if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
393 		seq_puts(m, ",default_permissions");
394 	if (fc->flags & FUSE_ALLOW_OTHER)
395 		seq_puts(m, ",allow_other");
396 	if (fc->max_read != ~0)
397 		seq_printf(m, ",max_read=%u", fc->max_read);
398 	return 0;
399 }
400 
401 static struct fuse_conn *new_conn(void)
402 {
403 	struct fuse_conn *fc;
404 
405 	fc = kzalloc(sizeof(*fc), GFP_KERNEL);
406 	if (fc) {
407 		spin_lock_init(&fc->lock);
408 		mutex_init(&fc->inst_mutex);
409 		atomic_set(&fc->count, 1);
410 		init_waitqueue_head(&fc->waitq);
411 		init_waitqueue_head(&fc->blocked_waitq);
412 		INIT_LIST_HEAD(&fc->pending);
413 		INIT_LIST_HEAD(&fc->processing);
414 		INIT_LIST_HEAD(&fc->io);
415 		INIT_LIST_HEAD(&fc->interrupts);
416 		atomic_set(&fc->num_waiting, 0);
417 		fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
418 		fc->bdi.unplug_io_fn = default_unplug_io_fn;
419 		fc->reqctr = 0;
420 		fc->blocked = 1;
421 		get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
422 	}
423 	return fc;
424 }
425 
426 void fuse_conn_put(struct fuse_conn *fc)
427 {
428 	if (atomic_dec_and_test(&fc->count)) {
429 		if (fc->destroy_req)
430 			fuse_request_free(fc->destroy_req);
431 		mutex_destroy(&fc->inst_mutex);
432 		kfree(fc);
433 	}
434 }
435 
436 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
437 {
438 	atomic_inc(&fc->count);
439 	return fc;
440 }
441 
442 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
443 {
444 	struct fuse_attr attr;
445 	memset(&attr, 0, sizeof(attr));
446 
447 	attr.mode = mode;
448 	attr.ino = FUSE_ROOT_ID;
449 	return fuse_iget(sb, 1, 0, &attr);
450 }
451 
452 static const struct super_operations fuse_super_operations = {
453 	.alloc_inode    = fuse_alloc_inode,
454 	.destroy_inode  = fuse_destroy_inode,
455 	.read_inode	= fuse_read_inode,
456 	.clear_inode	= fuse_clear_inode,
457 	.drop_inode	= generic_delete_inode,
458 	.remount_fs	= fuse_remount_fs,
459 	.put_super	= fuse_put_super,
460 	.umount_begin	= fuse_umount_begin,
461 	.statfs		= fuse_statfs,
462 	.show_options	= fuse_show_options,
463 };
464 
465 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
466 {
467 	struct fuse_init_out *arg = &req->misc.init_out;
468 
469 	if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
470 		fc->conn_error = 1;
471 	else {
472 		unsigned long ra_pages;
473 
474 		if (arg->minor >= 6) {
475 			ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
476 			if (arg->flags & FUSE_ASYNC_READ)
477 				fc->async_read = 1;
478 			if (!(arg->flags & FUSE_POSIX_LOCKS))
479 				fc->no_lock = 1;
480 		} else {
481 			ra_pages = fc->max_read / PAGE_CACHE_SIZE;
482 			fc->no_lock = 1;
483 		}
484 
485 		fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
486 		fc->minor = arg->minor;
487 		fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
488 		fc->conn_init = 1;
489 	}
490 	fuse_put_request(fc, req);
491 	fc->blocked = 0;
492 	wake_up_all(&fc->blocked_waitq);
493 }
494 
495 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
496 {
497 	struct fuse_init_in *arg = &req->misc.init_in;
498 
499 	arg->major = FUSE_KERNEL_VERSION;
500 	arg->minor = FUSE_KERNEL_MINOR_VERSION;
501 	arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
502 	arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
503 	req->in.h.opcode = FUSE_INIT;
504 	req->in.numargs = 1;
505 	req->in.args[0].size = sizeof(*arg);
506 	req->in.args[0].value = arg;
507 	req->out.numargs = 1;
508 	/* Variable length arguement used for backward compatibility
509 	   with interface version < 7.5.  Rest of init_out is zeroed
510 	   by do_get_request(), so a short reply is not a problem */
511 	req->out.argvar = 1;
512 	req->out.args[0].size = sizeof(struct fuse_init_out);
513 	req->out.args[0].value = &req->misc.init_out;
514 	req->end = process_init_reply;
515 	request_send_background(fc, req);
516 }
517 
518 static u64 conn_id(void)
519 {
520 	static u64 ctr = 1;
521 	return ctr++;
522 }
523 
524 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
525 {
526 	struct fuse_conn *fc;
527 	struct inode *root;
528 	struct fuse_mount_data d;
529 	struct file *file;
530 	struct dentry *root_dentry;
531 	struct fuse_req *init_req;
532 	int err;
533 	int is_bdev = sb->s_bdev != NULL;
534 
535 	if (sb->s_flags & MS_MANDLOCK)
536 		return -EINVAL;
537 
538 	if (!parse_fuse_opt((char *) data, &d, is_bdev))
539 		return -EINVAL;
540 
541 	if (is_bdev) {
542 #ifdef CONFIG_BLOCK
543 		if (!sb_set_blocksize(sb, d.blksize))
544 			return -EINVAL;
545 #endif
546 	} else {
547 		sb->s_blocksize = PAGE_CACHE_SIZE;
548 		sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
549 	}
550 	sb->s_magic = FUSE_SUPER_MAGIC;
551 	sb->s_op = &fuse_super_operations;
552 	sb->s_maxbytes = MAX_LFS_FILESIZE;
553 
554 	file = fget(d.fd);
555 	if (!file)
556 		return -EINVAL;
557 
558 	if (file->f_op != &fuse_dev_operations)
559 		return -EINVAL;
560 
561 	fc = new_conn();
562 	if (!fc)
563 		return -ENOMEM;
564 
565 	fc->flags = d.flags;
566 	fc->user_id = d.user_id;
567 	fc->group_id = d.group_id;
568 	fc->max_read = d.max_read;
569 
570 	/* Used by get_root_inode() */
571 	sb->s_fs_info = fc;
572 
573 	err = -ENOMEM;
574 	root = get_root_inode(sb, d.rootmode);
575 	if (!root)
576 		goto err;
577 
578 	root_dentry = d_alloc_root(root);
579 	if (!root_dentry) {
580 		iput(root);
581 		goto err;
582 	}
583 
584 	init_req = fuse_request_alloc();
585 	if (!init_req)
586 		goto err_put_root;
587 
588 	if (is_bdev) {
589 		fc->destroy_req = fuse_request_alloc();
590 		if (!fc->destroy_req)
591 			goto err_put_root;
592 	}
593 
594 	mutex_lock(&fuse_mutex);
595 	err = -EINVAL;
596 	if (file->private_data)
597 		goto err_unlock;
598 
599 	fc->id = conn_id();
600 	err = fuse_ctl_add_conn(fc);
601 	if (err)
602 		goto err_unlock;
603 
604 	list_add_tail(&fc->entry, &fuse_conn_list);
605 	sb->s_root = root_dentry;
606 	fc->connected = 1;
607 	file->private_data = fuse_conn_get(fc);
608 	mutex_unlock(&fuse_mutex);
609 	/*
610 	 * atomic_dec_and_test() in fput() provides the necessary
611 	 * memory barrier for file->private_data to be visible on all
612 	 * CPUs after this
613 	 */
614 	fput(file);
615 
616 	fuse_send_init(fc, init_req);
617 
618 	return 0;
619 
620  err_unlock:
621 	mutex_unlock(&fuse_mutex);
622 	fuse_request_free(init_req);
623  err_put_root:
624 	dput(root_dentry);
625  err:
626 	fput(file);
627 	fuse_conn_put(fc);
628 	return err;
629 }
630 
631 static int fuse_get_sb(struct file_system_type *fs_type,
632 		       int flags, const char *dev_name,
633 		       void *raw_data, struct vfsmount *mnt)
634 {
635 	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
636 }
637 
638 static struct file_system_type fuse_fs_type = {
639 	.owner		= THIS_MODULE,
640 	.name		= "fuse",
641 	.fs_flags	= FS_HAS_SUBTYPE,
642 	.get_sb		= fuse_get_sb,
643 	.kill_sb	= kill_anon_super,
644 };
645 
646 #ifdef CONFIG_BLOCK
647 static int fuse_get_sb_blk(struct file_system_type *fs_type,
648 			   int flags, const char *dev_name,
649 			   void *raw_data, struct vfsmount *mnt)
650 {
651 	return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
652 			   mnt);
653 }
654 
655 static struct file_system_type fuseblk_fs_type = {
656 	.owner		= THIS_MODULE,
657 	.name		= "fuseblk",
658 	.get_sb		= fuse_get_sb_blk,
659 	.kill_sb	= kill_block_super,
660 	.fs_flags	= FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
661 };
662 
663 static inline int register_fuseblk(void)
664 {
665 	return register_filesystem(&fuseblk_fs_type);
666 }
667 
668 static inline void unregister_fuseblk(void)
669 {
670 	unregister_filesystem(&fuseblk_fs_type);
671 }
672 #else
673 static inline int register_fuseblk(void)
674 {
675 	return 0;
676 }
677 
678 static inline void unregister_fuseblk(void)
679 {
680 }
681 #endif
682 
683 static decl_subsys(fuse, NULL, NULL);
684 static decl_subsys(connections, NULL, NULL);
685 
686 static void fuse_inode_init_once(void *foo, struct kmem_cache *cachep,
687 				 unsigned long flags)
688 {
689 	struct inode * inode = foo;
690 
691 	inode_init_once(inode);
692 }
693 
694 static int __init fuse_fs_init(void)
695 {
696 	int err;
697 
698 	err = register_filesystem(&fuse_fs_type);
699 	if (err)
700 		goto out;
701 
702 	err = register_fuseblk();
703 	if (err)
704 		goto out_unreg;
705 
706 	fuse_inode_cachep = kmem_cache_create("fuse_inode",
707 					      sizeof(struct fuse_inode),
708 					      0, SLAB_HWCACHE_ALIGN,
709 					      fuse_inode_init_once);
710 	err = -ENOMEM;
711 	if (!fuse_inode_cachep)
712 		goto out_unreg2;
713 
714 	return 0;
715 
716  out_unreg2:
717 	unregister_fuseblk();
718  out_unreg:
719 	unregister_filesystem(&fuse_fs_type);
720  out:
721 	return err;
722 }
723 
724 static void fuse_fs_cleanup(void)
725 {
726 	unregister_filesystem(&fuse_fs_type);
727 	unregister_fuseblk();
728 	kmem_cache_destroy(fuse_inode_cachep);
729 }
730 
731 static int fuse_sysfs_init(void)
732 {
733 	int err;
734 
735 	kobj_set_kset_s(&fuse_subsys, fs_subsys);
736 	err = subsystem_register(&fuse_subsys);
737 	if (err)
738 		goto out_err;
739 
740 	kobj_set_kset_s(&connections_subsys, fuse_subsys);
741 	err = subsystem_register(&connections_subsys);
742 	if (err)
743 		goto out_fuse_unregister;
744 
745 	return 0;
746 
747  out_fuse_unregister:
748 	subsystem_unregister(&fuse_subsys);
749  out_err:
750 	return err;
751 }
752 
753 static void fuse_sysfs_cleanup(void)
754 {
755 	subsystem_unregister(&connections_subsys);
756 	subsystem_unregister(&fuse_subsys);
757 }
758 
759 static int __init fuse_init(void)
760 {
761 	int res;
762 
763 	printk("fuse init (API version %i.%i)\n",
764 	       FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
765 
766 	INIT_LIST_HEAD(&fuse_conn_list);
767 	res = fuse_fs_init();
768 	if (res)
769 		goto err;
770 
771 	res = fuse_dev_init();
772 	if (res)
773 		goto err_fs_cleanup;
774 
775 	res = fuse_sysfs_init();
776 	if (res)
777 		goto err_dev_cleanup;
778 
779 	res = fuse_ctl_init();
780 	if (res)
781 		goto err_sysfs_cleanup;
782 
783 	return 0;
784 
785  err_sysfs_cleanup:
786 	fuse_sysfs_cleanup();
787  err_dev_cleanup:
788 	fuse_dev_cleanup();
789  err_fs_cleanup:
790 	fuse_fs_cleanup();
791  err:
792 	return res;
793 }
794 
795 static void __exit fuse_exit(void)
796 {
797 	printk(KERN_DEBUG "fuse exit\n");
798 
799 	fuse_ctl_cleanup();
800 	fuse_sysfs_cleanup();
801 	fuse_fs_cleanup();
802 	fuse_dev_cleanup();
803 }
804 
805 module_init(fuse_init);
806 module_exit(fuse_exit);
807