inode.c 29.7 KB
Newer Older
Miklos Szeredi's avatar
Miklos Szeredi committed
1
2
/*
  FUSE: Filesystem in Userspace
Miklos Szeredi's avatar
Miklos Szeredi committed
3
  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
Miklos Szeredi's avatar
Miklos Szeredi committed
4
5
6
7
8
9
10
11
12
13
14
15
16

  This program can be distributed under the terms of the GNU GPL.
  See the file COPYING.
*/

#include "fuse_i.h"

#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/module.h>
17
#include <linux/moduleparam.h>
Miklos Szeredi's avatar
Miklos Szeredi committed
18
19
#include <linux/parser.h>
#include <linux/statfs.h>
20
#include <linux/random.h>
Alexey Dobriyan's avatar
Alexey Dobriyan committed
21
#include <linux/sched.h>
Miklos Szeredi's avatar
Miklos Szeredi committed
22
#include <linux/exportfs.h>
Miklos Szeredi's avatar
Miklos Szeredi committed
23
24
25
26
27

MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
MODULE_DESCRIPTION("Filesystem in Userspace");
MODULE_LICENSE("GPL");

28
static struct kmem_cache *fuse_inode_cachep;
29
30
struct list_head fuse_conn_list;
DEFINE_MUTEX(fuse_mutex);
Miklos Szeredi's avatar
Miklos Szeredi committed
31

32
33
static int set_global_limit(const char *val, struct kernel_param *kp);

34
unsigned max_user_bgreq;
35
36
37
38
39
40
41
module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
		  &max_user_bgreq, 0644);
__MODULE_PARM_TYPE(max_user_bgreq, "uint");
MODULE_PARM_DESC(max_user_bgreq,
 "Global limit for the maximum number of backgrounded requests an "
 "unprivileged user can set");

42
unsigned max_user_congthresh;
43
44
45
46
47
48
49
module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
		  &max_user_congthresh, 0644);
__MODULE_PARM_TYPE(max_user_congthresh, "uint");
MODULE_PARM_DESC(max_user_congthresh,
 "Global limit for the maximum congestion threshold an "
 "unprivileged user can set");

Miklos Szeredi's avatar
Miklos Szeredi committed
50
51
#define FUSE_SUPER_MAGIC 0x65735546

Miklos Szeredi's avatar
Miklos Szeredi committed
52
53
#define FUSE_DEFAULT_BLKSIZE 512

54
55
56
57
58
59
/** Maximum number of outstanding background requests */
#define FUSE_DEFAULT_MAX_BACKGROUND 12

/** Congestion starts at 75% of maximum */
#define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)

Miklos Szeredi's avatar
Miklos Szeredi committed
60
61
62
struct fuse_mount_data {
	int fd;
	unsigned rootmode;
63
64
	kuid_t user_id;
	kgid_t group_id;
Miklos Szeredi's avatar
Miklos Szeredi committed
65
66
67
68
	unsigned fd_present:1;
	unsigned rootmode_present:1;
	unsigned user_id_present:1;
	unsigned group_id_present:1;
Miklos Szeredi's avatar
Miklos Szeredi committed
69
	unsigned flags;
70
	unsigned max_read;
71
	unsigned blksize;
Miklos Szeredi's avatar
Miklos Szeredi committed
72
73
};

74
struct fuse_forget_link *fuse_alloc_forget(void)
75
76
77
78
{
	return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
}

Miklos Szeredi's avatar
Miklos Szeredi committed
79
80
81
82
83
static struct inode *fuse_alloc_inode(struct super_block *sb)
{
	struct inode *inode;
	struct fuse_inode *fi;

84
	inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
Miklos Szeredi's avatar
Miklos Szeredi committed
85
86
87
88
	if (!inode)
		return NULL;

	fi = get_fuse_inode(inode);
Miklos Szeredi's avatar
Miklos Szeredi committed
89
	fi->i_time = 0;
Miklos Szeredi's avatar
Miklos Szeredi committed
90
	fi->nodeid = 0;
91
	fi->nlookup = 0;
92
	fi->attr_version = 0;
Miklos Szeredi's avatar
Miklos Szeredi committed
93
	fi->writectr = 0;
94
	fi->orig_ino = 0;
95
	fi->state = 0;
96
	INIT_LIST_HEAD(&fi->write_files);
Miklos Szeredi's avatar
Miklos Szeredi committed
97
98
99
	INIT_LIST_HEAD(&fi->queued_writes);
	INIT_LIST_HEAD(&fi->writepages);
	init_waitqueue_head(&fi->page_waitq);
100
101
	fi->forget = fuse_alloc_forget();
	if (!fi->forget) {
102
103
104
		kmem_cache_free(fuse_inode_cachep, inode);
		return NULL;
	}
Miklos Szeredi's avatar
Miklos Szeredi committed
105
106
107
108

	return inode;
}

Nick Piggin's avatar
Nick Piggin committed
109
110
111
112
113
114
static void fuse_i_callback(struct rcu_head *head)
{
	struct inode *inode = container_of(head, struct inode, i_rcu);
	kmem_cache_free(fuse_inode_cachep, inode);
}

Miklos Szeredi's avatar
Miklos Szeredi committed
115
116
static void fuse_destroy_inode(struct inode *inode)
{
117
	struct fuse_inode *fi = get_fuse_inode(inode);
118
	BUG_ON(!list_empty(&fi->write_files));
Miklos Szeredi's avatar
Miklos Szeredi committed
119
	BUG_ON(!list_empty(&fi->queued_writes));
120
	kfree(fi->forget);
Nick Piggin's avatar
Nick Piggin committed
121
	call_rcu(&inode->i_rcu, fuse_i_callback);
Miklos Szeredi's avatar
Miklos Szeredi committed
122
123
}

124
static void fuse_evict_inode(struct inode *inode)
Miklos Szeredi's avatar
Miklos Szeredi committed
125
{
126
	truncate_inode_pages(&inode->i_data, 0);
127
	clear_inode(inode);
Miklos Szeredi's avatar
Miklos Szeredi committed
128
129
	if (inode->i_sb->s_flags & MS_ACTIVE) {
		struct fuse_conn *fc = get_fuse_conn(inode);
130
		struct fuse_inode *fi = get_fuse_inode(inode);
131
132
		fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
		fi->forget = NULL;
133
	}
Miklos Szeredi's avatar
Miklos Szeredi committed
134
135
}

136
137
138
139
140
141
142
143
static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
{
	if (*flags & MS_MANDLOCK)
		return -EINVAL;

	return 0;
}

144
145
146
147
148
149
150
151
152
153
154
155
/*
 * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
 * so that it will fit.
 */
static ino_t fuse_squash_ino(u64 ino64)
{
	ino_t ino = (ino_t) ino64;
	if (sizeof(ino_t) < sizeof(u64))
		ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
	return ino;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
156
157
void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
				   u64 attr_valid)
Miklos Szeredi's avatar
Miklos Szeredi committed
158
{
Miklos Szeredi's avatar
Miklos Szeredi committed
159
	struct fuse_conn *fc = get_fuse_conn(inode);
160
	struct fuse_inode *fi = get_fuse_inode(inode);
Miklos Szeredi's avatar
Miklos Szeredi committed
161

162
163
164
	fi->attr_version = ++fc->attr_version;
	fi->i_time = attr_valid;

165
	inode->i_ino     = fuse_squash_ino(attr->ino);
166
	inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
Miklos Szeredi's avatar
Miklos Szeredi committed
167
	set_nlink(inode, attr->nlink);
168
169
	inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
	inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
Miklos Szeredi's avatar
Miklos Szeredi committed
170
171
172
173
174
175
176
	inode->i_blocks  = attr->blocks;
	inode->i_atime.tv_sec   = attr->atime;
	inode->i_atime.tv_nsec  = attr->atimensec;
	inode->i_mtime.tv_sec   = attr->mtime;
	inode->i_mtime.tv_nsec  = attr->mtimensec;
	inode->i_ctime.tv_sec   = attr->ctime;
	inode->i_ctime.tv_nsec  = attr->ctimensec;
177

178
179
180
181
182
	if (attr->blksize != 0)
		inode->i_blkbits = ilog2(attr->blksize);
	else
		inode->i_blkbits = inode->i_sb->s_blocksize_bits;

183
184
185
186
187
188
189
190
	/*
	 * Don't set the sticky bit in i_mode, unless we want the VFS
	 * to check permissions.  This prevents failures due to the
	 * check in may_delete().
	 */
	fi->orig_i_mode = inode->i_mode;
	if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
		inode->i_mode &= ~S_ISVTX;
191
192

	fi->orig_ino = attr->ino;
Miklos Szeredi's avatar
Miklos Szeredi committed
193
194
195
196
197
198
199
200
}

void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
			    u64 attr_valid, u64 attr_version)
{
	struct fuse_conn *fc = get_fuse_conn(inode);
	struct fuse_inode *fi = get_fuse_inode(inode);
	loff_t oldsize;
201
	struct timespec old_mtime;
Miklos Szeredi's avatar
Miklos Szeredi committed
202
203
204
205
206
207
208

	spin_lock(&fc->lock);
	if (attr_version != 0 && fi->attr_version > attr_version) {
		spin_unlock(&fc->lock);
		return;
	}

209
	old_mtime = inode->i_mtime;
Miklos Szeredi's avatar
Miklos Szeredi committed
210
	fuse_change_attributes_common(inode, attr, attr_valid);
211

212
213
214
215
	oldsize = inode->i_size;
	i_size_write(inode, attr->size);
	spin_unlock(&fc->lock);

216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
	if (S_ISREG(inode->i_mode)) {
		bool inval = false;

		if (oldsize != attr->size) {
			truncate_pagecache(inode, oldsize, attr->size);
			inval = true;
		} else if (fc->auto_inval_data) {
			struct timespec new_mtime = {
				.tv_sec = attr->mtime,
				.tv_nsec = attr->mtimensec,
			};

			/*
			 * Auto inval mode also checks and invalidates if mtime
			 * has changed.
			 */
			if (!timespec_equal(&old_mtime, &new_mtime))
				inval = true;
		}

		if (inval)
			invalidate_inode_pages2(inode->i_mapping);
238
	}
Miklos Szeredi's avatar
Miklos Szeredi committed
239
240
241
242
243
}

static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
{
	inode->i_mode = attr->mode & S_IFMT;
Miklos Szeredi's avatar
Miklos Szeredi committed
244
	inode->i_size = attr->size;
245
246
	if (S_ISREG(inode->i_mode)) {
		fuse_init_common(inode);
247
		fuse_init_file_inode(inode);
248
249
250
251
252
253
254
255
256
	} else if (S_ISDIR(inode->i_mode))
		fuse_init_dir(inode);
	else if (S_ISLNK(inode->i_mode))
		fuse_init_symlink(inode);
	else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
		 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
		fuse_init_common(inode);
		init_special_inode(inode, inode->i_mode,
				   new_decode_dev(attr->rdev));
257
258
	} else
		BUG();
Miklos Szeredi's avatar
Miklos Szeredi committed
259
260
}

John Muir's avatar
John Muir committed
261
int fuse_inode_eq(struct inode *inode, void *_nodeidp)
Miklos Szeredi's avatar
Miklos Szeredi committed
262
{
Miklos Szeredi's avatar
Miklos Szeredi committed
263
	u64 nodeid = *(u64 *) _nodeidp;
Miklos Szeredi's avatar
Miklos Szeredi committed
264
265
266
267
268
269
270
271
	if (get_node_id(inode) == nodeid)
		return 1;
	else
		return 0;
}

static int fuse_inode_set(struct inode *inode, void *_nodeidp)
{
Miklos Szeredi's avatar
Miklos Szeredi committed
272
	u64 nodeid = *(u64 *) _nodeidp;
Miklos Szeredi's avatar
Miklos Szeredi committed
273
274
275
276
	get_fuse_inode(inode)->nodeid = nodeid;
	return 0;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
277
struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
278
279
			int generation, struct fuse_attr *attr,
			u64 attr_valid, u64 attr_version)
Miklos Szeredi's avatar
Miklos Szeredi committed
280
281
{
	struct inode *inode;
282
	struct fuse_inode *fi;
Miklos Szeredi's avatar
Miklos Szeredi committed
283
284
285
286
287
288
289
290
	struct fuse_conn *fc = get_fuse_conn_super(sb);

 retry:
	inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
	if (!inode)
		return NULL;

	if ((inode->i_state & I_NEW)) {
291
		inode->i_flags |= S_NOATIME|S_NOCMTIME;
Miklos Szeredi's avatar
Miklos Szeredi committed
292
293
294
295
296
297
298
299
300
301
302
		inode->i_generation = generation;
		inode->i_data.backing_dev_info = &fc->bdi;
		fuse_init_inode(inode, attr);
		unlock_new_inode(inode);
	} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
		/* Inode has changed type, any I/O on the old should fail */
		make_bad_inode(inode);
		iput(inode);
		goto retry;
	}

303
	fi = get_fuse_inode(inode);
304
	spin_lock(&fc->lock);
Miklos Szeredi's avatar
Miklos Szeredi committed
305
	fi->nlookup++;
306
	spin_unlock(&fc->lock);
307
308
	fuse_change_attributes(inode, attr, attr_valid, attr_version);

Miklos Szeredi's avatar
Miklos Szeredi committed
309
310
311
	return inode;
}

John Muir's avatar
John Muir committed
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
			     loff_t offset, loff_t len)
{
	struct inode *inode;
	pgoff_t pg_start;
	pgoff_t pg_end;

	inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
	if (!inode)
		return -ENOENT;

	fuse_invalidate_attr(inode);
	if (offset >= 0) {
		pg_start = offset >> PAGE_CACHE_SHIFT;
		if (len <= 0)
			pg_end = -1;
		else
			pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
		invalidate_inode_pages2_range(inode->i_mapping,
					      pg_start, pg_end);
	}
	iput(inode);
	return 0;
}

337
static void fuse_umount_begin(struct super_block *sb)
338
{
339
	fuse_abort_conn(get_fuse_conn_super(sb));
340
341
}

342
343
344
345
346
347
348
static void fuse_send_destroy(struct fuse_conn *fc)
{
	struct fuse_req *req = fc->destroy_req;
	if (req && fc->conn_init) {
		fc->destroy_req = NULL;
		req->in.h.opcode = FUSE_DESTROY;
		req->force = 1;
349
		req->background = 0;
350
		fuse_request_send(fc, req);
351
352
353
354
		fuse_put_request(fc, req);
	}
}

355
static void fuse_bdi_destroy(struct fuse_conn *fc)
Miklos Szeredi's avatar
Miklos Szeredi committed
356
{
357
358
359
	if (fc->bdi_initialized)
		bdi_destroy(&fc->bdi);
}
Miklos Szeredi's avatar
Miklos Szeredi committed
360

361
void fuse_conn_kill(struct fuse_conn *fc)
362
{
363
	spin_lock(&fc->lock);
364
	fc->connected = 0;
365
	fc->blocked = 0;
366
	fc->initialized = 1;
367
	spin_unlock(&fc->lock);
368
	/* Flush all readers on this fs */
369
	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
370
	wake_up_all(&fc->waitq);
371
	wake_up_all(&fc->blocked_waitq);
372
	wake_up_all(&fc->reserved_req_waitq);
373
}
374
EXPORT_SYMBOL_GPL(fuse_conn_kill);
375
376
377
378
379
380

static void fuse_put_super(struct super_block *sb)
{
	struct fuse_conn *fc = get_fuse_conn_super(sb);

	fuse_send_destroy(fc);
Miklos Szeredi's avatar
Miklos Szeredi committed
381

382
	fuse_conn_kill(fc);
Miklos Szeredi's avatar
Miklos Szeredi committed
383
384
385
386
387
388
	mutex_lock(&fuse_mutex);
	list_del(&fc->entry);
	fuse_ctl_remove_conn(fc);
	mutex_unlock(&fuse_mutex);
	fuse_bdi_destroy(fc);

389
	fuse_conn_put(fc);
Miklos Szeredi's avatar
Miklos Szeredi committed
390
391
}

392
393
394
395
static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
{
	stbuf->f_type    = FUSE_SUPER_MAGIC;
	stbuf->f_bsize   = attr->bsize;
396
	stbuf->f_frsize  = attr->frsize;
397
398
399
400
401
402
403
404
405
	stbuf->f_blocks  = attr->blocks;
	stbuf->f_bfree   = attr->bfree;
	stbuf->f_bavail  = attr->bavail;
	stbuf->f_files   = attr->files;
	stbuf->f_ffree   = attr->ffree;
	stbuf->f_namelen = attr->namelen;
	/* fsid is left zero */
}

406
static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
407
{
408
	struct super_block *sb = dentry->d_sb;
409
410
411
412
413
	struct fuse_conn *fc = get_fuse_conn_super(sb);
	struct fuse_req *req;
	struct fuse_statfs_out outarg;
	int err;

414
	if (!fuse_allow_current_process(fc)) {
Miklos Szeredi's avatar
Miklos Szeredi committed
415
416
417
418
		buf->f_type = FUSE_SUPER_MAGIC;
		return 0;
	}

419
	req = fuse_get_req_nopages(fc);
420
421
	if (IS_ERR(req))
		return PTR_ERR(req);
422

423
	memset(&outarg, 0, sizeof(outarg));
424
425
	req->in.numargs = 0;
	req->in.h.opcode = FUSE_STATFS;
426
	req->in.h.nodeid = get_node_id(dentry->d_inode);
427
	req->out.numargs = 1;
428
429
	req->out.args[0].size =
		fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
430
	req->out.args[0].value = &outarg;
431
	fuse_request_send(fc, req);
432
433
434
435
436
437
438
	err = req->out.h.error;
	if (!err)
		convert_fuse_statfs(buf, &outarg.st);
	fuse_put_request(fc, req);
	return err;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
439
440
441
442
enum {
	OPT_FD,
	OPT_ROOTMODE,
	OPT_USER_ID,
443
	OPT_GROUP_ID,
Miklos Szeredi's avatar
Miklos Szeredi committed
444
445
	OPT_DEFAULT_PERMISSIONS,
	OPT_ALLOW_OTHER,
446
	OPT_MAX_READ,
447
	OPT_BLKSIZE,
Miklos Szeredi's avatar
Miklos Szeredi committed
448
449
450
	OPT_ERR
};

451
static const match_table_t tokens = {
Miklos Szeredi's avatar
Miklos Szeredi committed
452
453
454
	{OPT_FD,			"fd=%u"},
	{OPT_ROOTMODE,			"rootmode=%o"},
	{OPT_USER_ID,			"user_id=%u"},
455
	{OPT_GROUP_ID,			"group_id=%u"},
Miklos Szeredi's avatar
Miklos Szeredi committed
456
457
	{OPT_DEFAULT_PERMISSIONS,	"default_permissions"},
	{OPT_ALLOW_OTHER,		"allow_other"},
458
	{OPT_MAX_READ,			"max_read=%u"},
459
	{OPT_BLKSIZE,			"blksize=%u"},
Miklos Szeredi's avatar
Miklos Szeredi committed
460
461
462
	{OPT_ERR,			NULL}
};

463
static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
Miklos Szeredi's avatar
Miklos Szeredi committed
464
465
466
{
	char *p;
	memset(d, 0, sizeof(struct fuse_mount_data));
467
	d->max_read = ~0;
Miklos Szeredi's avatar
Miklos Szeredi committed
468
	d->blksize = FUSE_DEFAULT_BLKSIZE;
Miklos Szeredi's avatar
Miklos Szeredi committed
469
470
471
472
473
474
475
476
477
478
479
480
481
482

	while ((p = strsep(&opt, ",")) != NULL) {
		int token;
		int value;
		substring_t args[MAX_OPT_ARGS];
		if (!*p)
			continue;

		token = match_token(p, tokens, args);
		switch (token) {
		case OPT_FD:
			if (match_int(&args[0], &value))
				return 0;
			d->fd = value;
483
			d->fd_present = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
484
485
486
487
488
			break;

		case OPT_ROOTMODE:
			if (match_octal(&args[0], &value))
				return 0;
489
490
			if (!fuse_valid_type(value))
				return 0;
Miklos Szeredi's avatar
Miklos Szeredi committed
491
			d->rootmode = value;
492
			d->rootmode_present = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
493
494
495
496
497
			break;

		case OPT_USER_ID:
			if (match_int(&args[0], &value))
				return 0;
498
499
500
			d->user_id = make_kuid(current_user_ns(), value);
			if (!uid_valid(d->user_id))
				return 0;
501
			d->user_id_present = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
502
503
			break;

504
505
506
		case OPT_GROUP_ID:
			if (match_int(&args[0], &value))
				return 0;
507
508
509
			d->group_id = make_kgid(current_user_ns(), value);
			if (!gid_valid(d->group_id))
				return 0;
510
			d->group_id_present = 1;
511
512
			break;

Miklos Szeredi's avatar
Miklos Szeredi committed
513
514
515
516
517
518
519
520
		case OPT_DEFAULT_PERMISSIONS:
			d->flags |= FUSE_DEFAULT_PERMISSIONS;
			break;

		case OPT_ALLOW_OTHER:
			d->flags |= FUSE_ALLOW_OTHER;
			break;

521
522
523
524
525
526
		case OPT_MAX_READ:
			if (match_int(&args[0], &value))
				return 0;
			d->max_read = value;
			break;

527
528
529
530
531
532
		case OPT_BLKSIZE:
			if (!is_bdev || match_int(&args[0], &value))
				return 0;
			d->blksize = value;
			break;

Miklos Szeredi's avatar
Miklos Szeredi committed
533
534
535
536
		default:
			return 0;
		}
	}
537
538
539

	if (!d->fd_present || !d->rootmode_present ||
	    !d->user_id_present || !d->group_id_present)
Miklos Szeredi's avatar
Miklos Szeredi committed
540
541
542
543
544
		return 0;

	return 1;
}

545
static int fuse_show_options(struct seq_file *m, struct dentry *root)
Miklos Szeredi's avatar
Miklos Szeredi committed
546
{
547
548
	struct super_block *sb = root->d_sb;
	struct fuse_conn *fc = get_fuse_conn_super(sb);
Miklos Szeredi's avatar
Miklos Szeredi committed
549

550
551
	seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
	seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
Miklos Szeredi's avatar
Miklos Szeredi committed
552
553
554
555
	if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
		seq_puts(m, ",default_permissions");
	if (fc->flags & FUSE_ALLOW_OTHER)
		seq_puts(m, ",allow_other");
556
557
	if (fc->max_read != ~0)
		seq_printf(m, ",max_read=%u", fc->max_read);
558
559
	if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
		seq_printf(m, ",blksize=%lu", sb->s_blocksize);
Miklos Szeredi's avatar
Miklos Szeredi committed
560
561
562
	return 0;
}

563
void fuse_conn_init(struct fuse_conn *fc)
Miklos Szeredi's avatar
Miklos Szeredi committed
564
{
565
566
567
	memset(fc, 0, sizeof(*fc));
	spin_lock_init(&fc->lock);
	mutex_init(&fc->inst_mutex);
John Muir's avatar
John Muir committed
568
	init_rwsem(&fc->killsb);
569
570
571
572
573
574
575
576
577
578
	atomic_set(&fc->count, 1);
	init_waitqueue_head(&fc->waitq);
	init_waitqueue_head(&fc->blocked_waitq);
	init_waitqueue_head(&fc->reserved_req_waitq);
	INIT_LIST_HEAD(&fc->pending);
	INIT_LIST_HEAD(&fc->processing);
	INIT_LIST_HEAD(&fc->io);
	INIT_LIST_HEAD(&fc->interrupts);
	INIT_LIST_HEAD(&fc->bg_queue);
	INIT_LIST_HEAD(&fc->entry);
579
	fc->forget_list_tail = &fc->forget_list_head;
580
	atomic_set(&fc->num_waiting, 0);
581
582
	fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
	fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
583
584
585
	fc->khctr = 0;
	fc->polled_files = RB_ROOT;
	fc->reqctr = 0;
586
	fc->blocked = 0;
587
	fc->initialized = 0;
588
589
	fc->attr_version = 1;
	get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
Miklos Szeredi's avatar
Miklos Szeredi committed
590
}
591
EXPORT_SYMBOL_GPL(fuse_conn_init);
Miklos Szeredi's avatar
Miklos Szeredi committed
592

593
594
void fuse_conn_put(struct fuse_conn *fc)
{
595
	if (atomic_dec_and_test(&fc->count)) {
596
597
		if (fc->destroy_req)
			fuse_request_free(fc->destroy_req);
598
		mutex_destroy(&fc->inst_mutex);
Tejun Heo's avatar
Tejun Heo committed
599
		fc->release(fc);
600
	}
601
}
602
EXPORT_SYMBOL_GPL(fuse_conn_put);
603
604
605
606
607
608

struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
{
	atomic_inc(&fc->count);
	return fc;
}
609
EXPORT_SYMBOL_GPL(fuse_conn_get);
610

611
static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
Miklos Szeredi's avatar
Miklos Szeredi committed
612
613
614
615
616
617
{
	struct fuse_attr attr;
	memset(&attr, 0, sizeof(attr));

	attr.mode = mode;
	attr.ino = FUSE_ROOT_ID;
618
	attr.nlink = 1;
619
	return fuse_iget(sb, 1, 0, &attr, 0, 0);
Miklos Szeredi's avatar
Miklos Szeredi committed
620
621
}

Miklos Szeredi's avatar
Miklos Szeredi committed
622
struct fuse_inode_handle {
Miklos Szeredi's avatar
Miklos Szeredi committed
623
624
625
626
627
628
629
	u64 nodeid;
	u32 generation;
};

static struct dentry *fuse_get_dentry(struct super_block *sb,
				      struct fuse_inode_handle *handle)
{
630
	struct fuse_conn *fc = get_fuse_conn_super(sb);
Miklos Szeredi's avatar
Miklos Szeredi committed
631
632
633
634
635
636
637
638
	struct inode *inode;
	struct dentry *entry;
	int err = -ESTALE;

	if (handle->nodeid == 0)
		goto out_err;

	inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
	if (!inode) {
		struct fuse_entry_out outarg;
		struct qstr name;

		if (!fc->export_support)
			goto out_err;

		name.len = 1;
		name.name = ".";
		err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
				       &inode);
		if (err && err != -ENOENT)
			goto out_err;
		if (err || !inode) {
			err = -ESTALE;
			goto out_err;
		}
		err = -EIO;
		if (get_node_id(inode) != handle->nodeid)
			goto out_iput;
	}
Miklos Szeredi's avatar
Miklos Szeredi committed
660
661
662
663
	err = -ESTALE;
	if (inode->i_generation != handle->generation)
		goto out_iput;

664
	entry = d_obtain_alias(inode);
Al Viro's avatar
Al Viro committed
665
	if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
Miklos Szeredi's avatar
Miklos Szeredi committed
666
667
668
669
670
671
672
673
674
675
		fuse_invalidate_entry_cache(entry);

	return entry;

 out_iput:
	iput(inode);
 out_err:
	return ERR_PTR(err);
}

Al Viro's avatar
Al Viro committed
676
677
static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
			   struct inode *parent)
Miklos Szeredi's avatar
Miklos Szeredi committed
678
{
Al Viro's avatar
Al Viro committed
679
	int len = parent ? 6 : 3;
Miklos Szeredi's avatar
Miklos Szeredi committed
680
681
682
	u64 nodeid;
	u32 generation;

683
684
	if (*max_len < len) {
		*max_len = len;
685
		return  FILEID_INVALID;
686
	}
Miklos Szeredi's avatar
Miklos Szeredi committed
687
688
689
690
691
692
693
694

	nodeid = get_fuse_inode(inode)->nodeid;
	generation = inode->i_generation;

	fh[0] = (u32)(nodeid >> 32);
	fh[1] = (u32)(nodeid & 0xffffffff);
	fh[2] = generation;

Al Viro's avatar
Al Viro committed
695
	if (parent) {
Miklos Szeredi's avatar
Miklos Szeredi committed
696
697
698
699
700
701
702
703
704
		nodeid = get_fuse_inode(parent)->nodeid;
		generation = parent->i_generation;

		fh[3] = (u32)(nodeid >> 32);
		fh[4] = (u32)(nodeid & 0xffffffff);
		fh[5] = generation;
	}

	*max_len = len;
Al Viro's avatar
Al Viro committed
705
	return parent ? 0x82 : 0x81;
Miklos Szeredi's avatar
Miklos Szeredi committed
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
}

static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
		struct fid *fid, int fh_len, int fh_type)
{
	struct fuse_inode_handle handle;

	if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
		return NULL;

	handle.nodeid = (u64) fid->raw[0] << 32;
	handle.nodeid |= (u64) fid->raw[1];
	handle.generation = fid->raw[2];
	return fuse_get_dentry(sb, &handle);
}

static struct dentry *fuse_fh_to_parent(struct super_block *sb,
		struct fid *fid, int fh_len, int fh_type)
{
	struct fuse_inode_handle parent;

	if (fh_type != 0x82 || fh_len < 6)
		return NULL;

	parent.nodeid = (u64) fid->raw[3] << 32;
	parent.nodeid |= (u64) fid->raw[4];
	parent.generation = fid->raw[5];
	return fuse_get_dentry(sb, &parent);
}

736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
static struct dentry *fuse_get_parent(struct dentry *child)
{
	struct inode *child_inode = child->d_inode;
	struct fuse_conn *fc = get_fuse_conn(child_inode);
	struct inode *inode;
	struct dentry *parent;
	struct fuse_entry_out outarg;
	struct qstr name;
	int err;

	if (!fc->export_support)
		return ERR_PTR(-ESTALE);

	name.len = 2;
	name.name = "..";
	err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
			       &name, &outarg, &inode);
753
754
755
	if (err) {
		if (err == -ENOENT)
			return ERR_PTR(-ESTALE);
756
757
		return ERR_PTR(err);
	}
758
759

	parent = d_obtain_alias(inode);
Al Viro's avatar
Al Viro committed
760
	if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
761
762
763
764
		fuse_invalidate_entry_cache(parent);

	return parent;
}
Miklos Szeredi's avatar
Miklos Szeredi committed
765
766
767
768
769

static const struct export_operations fuse_export_operations = {
	.fh_to_dentry	= fuse_fh_to_dentry,
	.fh_to_parent	= fuse_fh_to_parent,
	.encode_fh	= fuse_encode_fh,
770
	.get_parent	= fuse_get_parent,
Miklos Szeredi's avatar
Miklos Szeredi committed
771
772
};

773
static const struct super_operations fuse_super_operations = {
Miklos Szeredi's avatar
Miklos Szeredi committed
774
775
	.alloc_inode    = fuse_alloc_inode,
	.destroy_inode  = fuse_destroy_inode,
776
	.evict_inode	= fuse_evict_inode,
Miklos Szeredi's avatar
Miklos Szeredi committed
777
	.drop_inode	= generic_delete_inode,
778
	.remount_fs	= fuse_remount_fs,
Miklos Szeredi's avatar
Miklos Szeredi committed
779
	.put_super	= fuse_put_super,
780
	.umount_begin	= fuse_umount_begin,
781
	.statfs		= fuse_statfs,
Miklos Szeredi's avatar
Miklos Szeredi committed
782
783
784
	.show_options	= fuse_show_options,
};

785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
static void sanitize_global_limit(unsigned *limit)
{
	if (*limit == 0)
		*limit = ((num_physpages << PAGE_SHIFT) >> 13) /
			 sizeof(struct fuse_req);

	if (*limit >= 1 << 16)
		*limit = (1 << 16) - 1;
}

static int set_global_limit(const char *val, struct kernel_param *kp)
{
	int rv;

	rv = param_set_uint(val, kp);
	if (rv)
		return rv;

	sanitize_global_limit((unsigned *)kp->arg);

	return 0;
}

static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
{
	int cap_sys_admin = capable(CAP_SYS_ADMIN);

	if (arg->minor < 13)
		return;

	sanitize_global_limit(&max_user_bgreq);
	sanitize_global_limit(&max_user_congthresh);

	if (arg->max_background) {
		fc->max_background = arg->max_background;

		if (!cap_sys_admin && fc->max_background > max_user_bgreq)
			fc->max_background = max_user_bgreq;
	}
	if (arg->congestion_threshold) {
		fc->congestion_threshold = arg->congestion_threshold;

		if (!cap_sys_admin &&
		    fc->congestion_threshold > max_user_congthresh)
			fc->congestion_threshold = max_user_congthresh;
	}
}

833
834
835
836
837
838
839
static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
{
	struct fuse_init_out *arg = &req->misc.init_out;

	if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
		fc->conn_error = 1;
	else {
840
841
		unsigned long ra_pages;

842
843
		process_init_limits(fc, arg);

844
845
846
847
		if (arg->minor >= 6) {
			ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
			if (arg->flags & FUSE_ASYNC_READ)
				fc->async_read = 1;
848
849
			if (!(arg->flags & FUSE_POSIX_LOCKS))
				fc->no_lock = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
850
851
852
			if (arg->minor >= 17) {
				if (!(arg->flags & FUSE_FLOCK_LOCKS))
					fc->no_flock = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
853
854
855
			} else {
				if (!(arg->flags & FUSE_POSIX_LOCKS))
					fc->no_flock = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
856
			}
857
858
			if (arg->flags & FUSE_ATOMIC_O_TRUNC)
				fc->atomic_o_trunc = 1;
859
860
861
862
863
			if (arg->minor >= 9) {
				/* LOOKUP has dependency on proto version */
				if (arg->flags & FUSE_EXPORT_SUPPORT)
					fc->export_support = 1;
			}
864
865
			if (arg->flags & FUSE_BIG_WRITES)
				fc->big_writes = 1;
866
867
			if (arg->flags & FUSE_DONT_MASK)
				fc->dont_mask = 1;
868
869
			if (arg->flags & FUSE_AUTO_INVAL_DATA)
				fc->auto_inval_data = 1;
870
871
			if (arg->flags & FUSE_DO_READDIRPLUS)
				fc->do_readdirplus = 1;
872
873
			if (arg->flags & FUSE_READDIRPLUS_AUTO)
				fc->readdirplus_auto = 1;
874
875
			if (arg->flags & FUSE_ASYNC_DIO)
				fc->async_dio = 1;
876
		} else {
877
			ra_pages = fc->max_read / PAGE_CACHE_SIZE;
878
			fc->no_lock = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
879
			fc->no_flock = 1;
880
		}
881
882

		fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
883
884
		fc->minor = arg->minor;
		fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
885
		fc->max_write = max_t(unsigned, 4096, fc->max_write);
886
		fc->conn_init = 1;
887
	}
888
	fc->initialized = 1;
889
	wake_up_all(&fc->blocked_waitq);
890
891
}

892
static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
893
894
{
	struct fuse_init_in *arg = &req->misc.init_in;
895

896
897
	arg->major = FUSE_KERNEL_VERSION;
	arg->minor = FUSE_KERNEL_MINOR_VERSION;
898
	arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
899
	arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
Miklos Szeredi's avatar
Miklos Szeredi committed
900
		FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
Miklos Szeredi's avatar
Miklos Szeredi committed
901
		FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
902
		FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
903
		FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO;
904
905
906
907
908
	req->in.h.opcode = FUSE_INIT;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(*arg);
	req->in.args[0].value = arg;
	req->out.numargs = 1;
909
	/* Variable length argument used for backward compatibility
910
911
912
913
914
915
	   with interface version < 7.5.  Rest of init_out is zeroed
	   by do_get_request(), so a short reply is not a problem */
	req->out.argvar = 1;
	req->out.args[0].size = sizeof(struct fuse_init_out);
	req->out.args[0].value = &req->misc.init_out;
	req->end = process_init_reply;
916
	fuse_request_send_background(fc, req);
917
918
}

Tejun Heo's avatar
Tejun Heo committed
919
920
921
922
923
static void fuse_free_conn(struct fuse_conn *fc)
{
	kfree(fc);
}

924
925
926
927
static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
{
	int err;

928
	fc->bdi.name = "fuse";
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
	fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
	/* fuse does it's own writeback accounting */
	fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB;

	err = bdi_init(&fc->bdi);
	if (err)
		return err;

	fc->bdi_initialized = 1;

	if (sb->s_bdev) {
		err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
				    MAJOR(fc->dev), MINOR(fc->dev));
	} else {
		err = bdi_register_dev(&fc->bdi, fc->dev);
	}

	if (err)
		return err;

	/*
	 * For a single fuse filesystem use max 1% of dirty +
	 * writeback threshold.
	 *
	 * This gives about 1M of write buffer for memory maps on a
	 * machine with 1G and 10% dirty_ratio, which should be more
	 * than enough.
	 *
	 * Privileged users can raise it by writing to
	 *
	 *    /sys/class/bdi/<bdi>/max_ratio
	 */
	bdi_set_max_ratio(&fc->bdi, 1);

	return 0;
}

Miklos Szeredi's avatar
Miklos Szeredi committed
966
967
968
969
970
971
static int fuse_fill_super(struct super_block *sb, void *data, int silent)
{
	struct fuse_conn *fc;
	struct inode *root;
	struct fuse_mount_data d;
	struct file *file;
972
	struct dentry *root_dentry;
973
	struct fuse_req *init_req;
Miklos Szeredi's avatar
Miklos Szeredi committed
974
	int err;
975
	int is_bdev = sb->s_bdev != NULL;
Miklos Szeredi's avatar
Miklos Szeredi committed
976

977
	err = -EINVAL;
978
	if (sb->s_flags & MS_MANDLOCK)
979
		goto err;
980

Al Viro's avatar
Al Viro committed
981
982
	sb->s_flags &= ~MS_NOSEC;

983
	if (!parse_fuse_opt((char *) data, &d, is_bdev))
984
		goto err;
Miklos Szeredi's avatar
Miklos Szeredi committed
985

986
	if (is_bdev) {
987
#ifdef CONFIG_BLOCK
988
		err = -EINVAL;
989
		if (!sb_set_blocksize(sb, d.blksize))
990
			goto err;
991
#endif
992
993
994
995
	} else {
		sb->s_blocksize = PAGE_CACHE_SIZE;
		sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	}
Miklos Szeredi's avatar
Miklos Szeredi committed
996
997
998
	sb->s_magic = FUSE_SUPER_MAGIC;
	sb->s_op = &fuse_super_operations;
	sb->s_maxbytes = MAX_LFS_FILESIZE;
999
	sb->s_time_gran = 1;
Miklos Szeredi's avatar
Miklos Szeredi committed
1000
	sb->s_export_op = &fuse_export_operations;
Miklos Szeredi's avatar
Miklos Szeredi committed
1001
1002

	file = fget(d.fd);
1003
	err = -EINVAL;
Miklos Szeredi's avatar
Miklos Szeredi committed
1004
	if (!file)
1005
		goto err;
Miklos Szeredi's avatar
Miklos Szeredi committed
1006

1007
1008
	if ((file->f_op != &fuse_dev_operations) ||
	    (file->f_cred->user_ns != &init_user_ns))
1009
		goto err_fput;
1010

1011
	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1012
1013
1014
	err = -ENOMEM;
	if (!fc)
		goto err_fput;
Miklos Szeredi's avatar
Miklos Szeredi committed
1015

1016
1017
1018
	fuse_conn_init(fc);

	fc->dev = sb->s_dev;
John Muir's avatar
John Muir committed
1019
	fc->sb = sb;
1020
1021
1022
	err = fuse_bdi_init(fc, sb);
	if (err)
		goto err_put_conn;
1023

Jens Axboe's avatar
Jens Axboe committed
1024
1025
	sb->s_bdi = &fc->bdi;

1026
1027
1028
1029
1030
	/* Handle umasking inside the fuse code */
	if (sb->s_flags & MS_POSIXACL)
		fc->dont_mask = 1;
	sb->s_flags |= MS_POSIXACL;

Tejun Heo's avatar
Tejun Heo committed
1031
	fc->release = fuse_free_conn;
Miklos Szeredi's avatar
Miklos Szeredi committed
1032
	fc->flags = d.flags;
Miklos Szeredi's avatar
Miklos Szeredi committed
1033
	fc->user_id = d.user_id;
1034
	fc->group_id = d.group_id;
1035
	fc->max_read = max_t(unsigned, 4096, d.max_read);
Miklos Szeredi's avatar
Miklos Szeredi committed
1036

1037
1038
1039
	/* Used by get_root_inode() */
	sb->s_fs_info = fc;

Miklos Szeredi's avatar
Miklos Szeredi committed
1040
	err = -ENOMEM;
1041
	root = fuse_get_root_inode(sb, d.rootmode);
1042
1043
	root_dentry = d_make_root(root);
	if (!root_dentry)
1044
		goto err_put_conn;
Al Viro's avatar
Al Viro committed
1045
1046
	/* only now - we want root dentry with NULL ->d_op */
	sb->s_d_op = &fuse_dentry_operations;
1047

1048
	init_req = fuse_request_alloc(0);
1049
1050
	if (!init_req)
		goto err_put_root;
1051
	init_req->background = 1;
1052

1053
	if (is_bdev) {
1054
		fc->destroy_req = fuse_request_alloc(0);
1055
		if (!fc->destroy_req)
1056
			goto err_free_init_req;
1057
1058
	}

1059
	mutex_lock(&fuse_mutex);
1060
1061
	err = -EINVAL;
	if (file->private_data)
1062
		goto err_unlock;
1063

1064
1065
1066
1067
1068
	err = fuse_ctl_add_conn(fc);
	if (err)
		goto err_unlock;

	list_add_tail(&fc->entry, &fuse_conn_list);
1069
1070
	sb->s_root = root_dentry;
	fc->connected = 1;
1071
1072
	file->private_data = fuse_conn_get(fc);
	mutex_unlock(&fuse_mutex);
1073
1074
1075
1076
1077
1078
	/*
	 * atomic_dec_and_test() in fput() provides the necessary
	 * memory barrier for file->private_data to be visible on all
	 * CPUs after this
	 */
	fput(file);
1079

1080
	fuse_send_init(fc, init_req);
1081

Miklos Szeredi's avatar
Miklos Szeredi committed
1082
1083
	return 0;

1084
1085
 err_unlock:
	mutex_unlock(&fuse_mutex);
1086
 err_free_init_req:
1087
	fuse_request_free(init_req);
1088
1089
 err_put_root:
	dput(root_dentry);
1090
 err_put_conn:
1091
	fuse_bdi_destroy(fc);
1092
	fuse_conn_put(fc);
1093
1094
1095
 err_fput:
	fput(file);
 err:
Miklos Szeredi's avatar
Miklos Szeredi committed
1096
1097
1098
	return err;
}

Al Viro's avatar
Al Viro committed
1099
static struct dentry *fuse_mount(struct file_system_type *fs_type,
1100
		       int flags, const char *dev_name,
Al Viro's avatar
Al Viro committed
1101
		       void *raw_data)
Miklos Szeredi's avatar
Miklos Szeredi committed
1102
{
Al Viro's avatar
Al Viro committed
1103
	return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
Miklos Szeredi's avatar
Miklos Szeredi committed
1104
1105
}

John Muir's avatar
John Muir committed
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
static void fuse_kill_sb_anon(struct super_block *sb)
{
	struct fuse_conn *fc = get_fuse_conn_super(sb);

	if (fc) {
		down_write(&fc->killsb);
		fc->sb = NULL;
		up_write(&fc->killsb);
	}

	kill_anon_super(sb);
}

1119
1120
1121
static struct file_system_type fuse_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "fuse",
1122
	.fs_flags	= FS_HAS_SUBTYPE,
Al Viro's avatar
Al Viro committed
1123
	.mount		= fuse_mount,
John Muir's avatar
John Muir committed
1124
	.kill_sb	= fuse_kill_sb_anon,
1125
};