inode.c 25.2 KB
Newer Older
M
Miklos Szeredi 已提交
1 2
/*
  FUSE: Filesystem in Userspace
M
Miklos Szeredi 已提交
3
  Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
M
Miklos Szeredi 已提交
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

  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>
#include <linux/parser.h>
#include <linux/statfs.h>
19
#include <linux/random.h>
A
Alexey Dobriyan 已提交
20
#include <linux/sched.h>
M
Miklos Szeredi 已提交
21
#include <linux/exportfs.h>
M
Miklos Szeredi 已提交
22 23 24 25 26

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

27
static struct kmem_cache *fuse_inode_cachep;
28 29
struct list_head fuse_conn_list;
DEFINE_MUTEX(fuse_mutex);
M
Miklos Szeredi 已提交
30 31 32

#define FUSE_SUPER_MAGIC 0x65735546

M
Miklos Szeredi 已提交
33 34
#define FUSE_DEFAULT_BLKSIZE 512

M
Miklos Szeredi 已提交
35 36 37 38
struct fuse_mount_data {
	int fd;
	unsigned rootmode;
	unsigned user_id;
39
	unsigned group_id;
M
Miklos Szeredi 已提交
40 41 42 43
	unsigned fd_present:1;
	unsigned rootmode_present:1;
	unsigned user_id_present:1;
	unsigned group_id_present:1;
M
Miklos Szeredi 已提交
44
	unsigned flags;
45
	unsigned max_read;
M
Miklos Szeredi 已提交
46
	unsigned blksize;
M
Miklos Szeredi 已提交
47 48 49 50 51 52 53
};

static struct inode *fuse_alloc_inode(struct super_block *sb)
{
	struct inode *inode;
	struct fuse_inode *fi;

54
	inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
M
Miklos Szeredi 已提交
55 56 57 58
	if (!inode)
		return NULL;

	fi = get_fuse_inode(inode);
M
Miklos Szeredi 已提交
59
	fi->i_time = 0;
M
Miklos Szeredi 已提交
60
	fi->nodeid = 0;
61
	fi->nlookup = 0;
62
	fi->attr_version = 0;
M
Miklos Szeredi 已提交
63
	fi->writectr = 0;
64
	INIT_LIST_HEAD(&fi->write_files);
M
Miklos Szeredi 已提交
65 66 67
	INIT_LIST_HEAD(&fi->queued_writes);
	INIT_LIST_HEAD(&fi->writepages);
	init_waitqueue_head(&fi->page_waitq);
68 69 70 71 72
	fi->forget_req = fuse_request_alloc();
	if (!fi->forget_req) {
		kmem_cache_free(fuse_inode_cachep, inode);
		return NULL;
	}
M
Miklos Szeredi 已提交
73 74 75 76 77 78

	return inode;
}

static void fuse_destroy_inode(struct inode *inode)
{
79
	struct fuse_inode *fi = get_fuse_inode(inode);
80
	BUG_ON(!list_empty(&fi->write_files));
M
Miklos Szeredi 已提交
81
	BUG_ON(!list_empty(&fi->queued_writes));
82 83
	if (fi->forget_req)
		fuse_request_free(fi->forget_req);
M
Miklos Szeredi 已提交
84 85 86
	kmem_cache_free(fuse_inode_cachep, inode);
}

87
void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
M
Miklos Szeredi 已提交
88
		      u64 nodeid, u64 nlookup)
89 90
{
	struct fuse_forget_in *inarg = &req->misc.forget_in;
91
	inarg->nlookup = nlookup;
92 93 94 95 96
	req->in.h.opcode = FUSE_FORGET;
	req->in.h.nodeid = nodeid;
	req->in.numargs = 1;
	req->in.args[0].size = sizeof(struct fuse_forget_in);
	req->in.args[0].value = inarg;
97
	fuse_request_send_noreply(fc, req);
98 99
}

M
Miklos Szeredi 已提交
100 101
static void fuse_clear_inode(struct inode *inode)
{
M
Miklos Szeredi 已提交
102 103
	if (inode->i_sb->s_flags & MS_ACTIVE) {
		struct fuse_conn *fc = get_fuse_conn(inode);
104
		struct fuse_inode *fi = get_fuse_inode(inode);
105
		fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
106 107
		fi->forget_req = NULL;
	}
M
Miklos Szeredi 已提交
108 109
}

110 111 112 113 114 115 116 117
static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
{
	if (*flags & MS_MANDLOCK)
		return -EINVAL;

	return 0;
}

M
Miklos Szeredi 已提交
118
void fuse_truncate(struct address_space *mapping, loff_t offset)
119 120 121 122 123 124 125
{
	/* See vmtruncate() */
	unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
	truncate_inode_pages(mapping, offset);
	unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
}

M
Miklos Szeredi 已提交
126 127
void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
				   u64 attr_valid)
M
Miklos Szeredi 已提交
128
{
M
Miklos Szeredi 已提交
129
	struct fuse_conn *fc = get_fuse_conn(inode);
130
	struct fuse_inode *fi = get_fuse_inode(inode);
M
Miklos Szeredi 已提交
131

132 133 134
	fi->attr_version = ++fc->attr_version;
	fi->i_time = attr_valid;

M
Miklos Szeredi 已提交
135
	inode->i_ino     = attr->ino;
136
	inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
M
Miklos Szeredi 已提交
137 138 139 140 141 142 143 144 145 146
	inode->i_nlink   = attr->nlink;
	inode->i_uid     = attr->uid;
	inode->i_gid     = attr->gid;
	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;
147

148 149 150 151 152
	if (attr->blksize != 0)
		inode->i_blkbits = ilog2(attr->blksize);
	else
		inode->i_blkbits = inode->i_sb->s_blocksize_bits;

153 154 155 156 157 158 159 160
	/*
	 * 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;
M
Miklos Szeredi 已提交
161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176
}

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;

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

	fuse_change_attributes_common(inode, attr, attr_valid);
177

178 179 180 181 182 183 184
	oldsize = inode->i_size;
	i_size_write(inode, attr->size);
	spin_unlock(&fc->lock);

	if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
		if (attr->size < oldsize)
			fuse_truncate(inode->i_mapping, attr->size);
M
Miklos Szeredi 已提交
185
		invalidate_inode_pages2(inode->i_mapping);
186
	}
M
Miklos Szeredi 已提交
187 188 189 190 191
}

static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
{
	inode->i_mode = attr->mode & S_IFMT;
M
Miklos Szeredi 已提交
192
	inode->i_size = attr->size;
193 194
	if (S_ISREG(inode->i_mode)) {
		fuse_init_common(inode);
M
Miklos Szeredi 已提交
195
		fuse_init_file_inode(inode);
196 197 198 199 200 201 202 203 204
	} 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));
205 206
	} else
		BUG();
M
Miklos Szeredi 已提交
207 208 209 210
}

static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
{
M
Miklos Szeredi 已提交
211
	u64 nodeid = *(u64 *) _nodeidp;
M
Miklos Szeredi 已提交
212 213 214 215 216 217 218 219
	if (get_node_id(inode) == nodeid)
		return 1;
	else
		return 0;
}

static int fuse_inode_set(struct inode *inode, void *_nodeidp)
{
M
Miklos Szeredi 已提交
220
	u64 nodeid = *(u64 *) _nodeidp;
M
Miklos Szeredi 已提交
221 222 223 224
	get_fuse_inode(inode)->nodeid = nodeid;
	return 0;
}

M
Miklos Szeredi 已提交
225
struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
226 227
			int generation, struct fuse_attr *attr,
			u64 attr_valid, u64 attr_version)
M
Miklos Szeredi 已提交
228 229
{
	struct inode *inode;
230
	struct fuse_inode *fi;
M
Miklos Szeredi 已提交
231 232 233 234 235 236 237 238
	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)) {
239
		inode->i_flags |= S_NOATIME|S_NOCMTIME;
M
Miklos Szeredi 已提交
240 241 242 243 244 245 246 247 248 249 250
		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;
	}

251
	fi = get_fuse_inode(inode);
252
	spin_lock(&fc->lock);
M
Miklos Szeredi 已提交
253
	fi->nlookup++;
254
	spin_unlock(&fc->lock);
255 256
	fuse_change_attributes(inode, attr, attr_valid, attr_version);

M
Miklos Szeredi 已提交
257 258 259
	return inode;
}

260
static void fuse_umount_begin(struct super_block *sb)
261
{
262
	fuse_abort_conn(get_fuse_conn_super(sb));
263 264
}

265 266 267 268 269 270 271
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;
272
		fuse_request_send(fc, req);
273 274 275 276
		fuse_put_request(fc, req);
	}
}

277
static void fuse_bdi_destroy(struct fuse_conn *fc)
M
Miklos Szeredi 已提交
278
{
279 280 281
	if (fc->bdi_initialized)
		bdi_destroy(&fc->bdi);
}
M
Miklos Szeredi 已提交
282

283
void fuse_conn_kill(struct fuse_conn *fc)
284
{
285
	spin_lock(&fc->lock);
286
	fc->connected = 0;
287
	fc->blocked = 0;
288
	spin_unlock(&fc->lock);
M
Miklos Szeredi 已提交
289
	/* Flush all readers on this fs */
290
	kill_fasync(&fc->fasync, SIGIO, POLL_IN);
M
Miklos Szeredi 已提交
291
	wake_up_all(&fc->waitq);
292
	wake_up_all(&fc->blocked_waitq);
293
	wake_up_all(&fc->reserved_req_waitq);
294 295 296 297
	mutex_lock(&fuse_mutex);
	list_del(&fc->entry);
	fuse_ctl_remove_conn(fc);
	mutex_unlock(&fuse_mutex);
298 299
	fuse_bdi_destroy(fc);
}
300
EXPORT_SYMBOL_GPL(fuse_conn_kill);
301 302 303 304 305 306 307

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

	fuse_send_destroy(fc);
	fuse_conn_kill(fc);
308
	fuse_conn_put(fc);
M
Miklos Szeredi 已提交
309 310
}

311 312 313 314
static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
{
	stbuf->f_type    = FUSE_SUPER_MAGIC;
	stbuf->f_bsize   = attr->bsize;
315
	stbuf->f_frsize  = attr->frsize;
316 317 318 319 320 321 322 323 324
	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 */
}

325
static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
326
{
327
	struct super_block *sb = dentry->d_sb;
328 329 330 331 332
	struct fuse_conn *fc = get_fuse_conn_super(sb);
	struct fuse_req *req;
	struct fuse_statfs_out outarg;
	int err;

M
Miklos Szeredi 已提交
333 334 335 336 337
	if (!fuse_allow_task(fc, current)) {
		buf->f_type = FUSE_SUPER_MAGIC;
		return 0;
	}

338 339 340
	req = fuse_get_req(fc);
	if (IS_ERR(req))
		return PTR_ERR(req);
341

342
	memset(&outarg, 0, sizeof(outarg));
343 344
	req->in.numargs = 0;
	req->in.h.opcode = FUSE_STATFS;
345
	req->in.h.nodeid = get_node_id(dentry->d_inode);
346
	req->out.numargs = 1;
347 348
	req->out.args[0].size =
		fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
349
	req->out.args[0].value = &outarg;
350
	fuse_request_send(fc, req);
351 352 353 354 355 356 357
	err = req->out.h.error;
	if (!err)
		convert_fuse_statfs(buf, &outarg.st);
	fuse_put_request(fc, req);
	return err;
}

M
Miklos Szeredi 已提交
358 359 360 361
enum {
	OPT_FD,
	OPT_ROOTMODE,
	OPT_USER_ID,
362
	OPT_GROUP_ID,
M
Miklos Szeredi 已提交
363 364
	OPT_DEFAULT_PERMISSIONS,
	OPT_ALLOW_OTHER,
365
	OPT_MAX_READ,
M
Miklos Szeredi 已提交
366
	OPT_BLKSIZE,
M
Miklos Szeredi 已提交
367 368 369
	OPT_ERR
};

370
static const match_table_t tokens = {
M
Miklos Szeredi 已提交
371 372 373
	{OPT_FD,			"fd=%u"},
	{OPT_ROOTMODE,			"rootmode=%o"},
	{OPT_USER_ID,			"user_id=%u"},
374
	{OPT_GROUP_ID,			"group_id=%u"},
M
Miklos Szeredi 已提交
375 376
	{OPT_DEFAULT_PERMISSIONS,	"default_permissions"},
	{OPT_ALLOW_OTHER,		"allow_other"},
377
	{OPT_MAX_READ,			"max_read=%u"},
M
Miklos Szeredi 已提交
378
	{OPT_BLKSIZE,			"blksize=%u"},
M
Miklos Szeredi 已提交
379 380 381
	{OPT_ERR,			NULL}
};

M
Miklos Szeredi 已提交
382
static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
M
Miklos Szeredi 已提交
383 384 385
{
	char *p;
	memset(d, 0, sizeof(struct fuse_mount_data));
386
	d->max_read = ~0;
M
Miklos Szeredi 已提交
387
	d->blksize = FUSE_DEFAULT_BLKSIZE;
M
Miklos Szeredi 已提交
388 389 390 391 392 393 394 395 396 397 398 399 400 401

	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;
402
			d->fd_present = 1;
M
Miklos Szeredi 已提交
403 404 405 406 407
			break;

		case OPT_ROOTMODE:
			if (match_octal(&args[0], &value))
				return 0;
408 409
			if (!fuse_valid_type(value))
				return 0;
M
Miklos Szeredi 已提交
410
			d->rootmode = value;
411
			d->rootmode_present = 1;
M
Miklos Szeredi 已提交
412 413 414 415 416 417
			break;

		case OPT_USER_ID:
			if (match_int(&args[0], &value))
				return 0;
			d->user_id = value;
418
			d->user_id_present = 1;
M
Miklos Szeredi 已提交
419 420
			break;

421 422 423 424
		case OPT_GROUP_ID:
			if (match_int(&args[0], &value))
				return 0;
			d->group_id = value;
425
			d->group_id_present = 1;
426 427
			break;

M
Miklos Szeredi 已提交
428 429 430 431 432 433 434 435
		case OPT_DEFAULT_PERMISSIONS:
			d->flags |= FUSE_DEFAULT_PERMISSIONS;
			break;

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

436 437 438 439 440 441
		case OPT_MAX_READ:
			if (match_int(&args[0], &value))
				return 0;
			d->max_read = value;
			break;

M
Miklos Szeredi 已提交
442 443 444 445 446 447
		case OPT_BLKSIZE:
			if (!is_bdev || match_int(&args[0], &value))
				return 0;
			d->blksize = value;
			break;

M
Miklos Szeredi 已提交
448 449 450 451
		default:
			return 0;
		}
	}
452 453 454

	if (!d->fd_present || !d->rootmode_present ||
	    !d->user_id_present || !d->group_id_present)
M
Miklos Szeredi 已提交
455 456 457 458 459 460 461 462 463 464
		return 0;

	return 1;
}

static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
{
	struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);

	seq_printf(m, ",user_id=%u", fc->user_id);
465
	seq_printf(m, ",group_id=%u", fc->group_id);
M
Miklos Szeredi 已提交
466 467 468 469
	if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
		seq_puts(m, ",default_permissions");
	if (fc->flags & FUSE_ALLOW_OTHER)
		seq_puts(m, ",allow_other");
470 471
	if (fc->max_read != ~0)
		seq_printf(m, ",max_read=%u", fc->max_read);
M
Miklos Szeredi 已提交
472 473 474
	if (mnt->mnt_sb->s_bdev &&
	    mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
		seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
M
Miklos Szeredi 已提交
475 476 477
	return 0;
}

478
void fuse_conn_init(struct fuse_conn *fc)
M
Miklos Szeredi 已提交
479
{
480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499
	memset(fc, 0, sizeof(*fc));
	spin_lock_init(&fc->lock);
	mutex_init(&fc->inst_mutex);
	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);
	atomic_set(&fc->num_waiting, 0);
	fc->khctr = 0;
	fc->polled_files = RB_ROOT;
	fc->reqctr = 0;
	fc->blocked = 1;
	fc->attr_version = 1;
	get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
M
Miklos Szeredi 已提交
500
}
501
EXPORT_SYMBOL_GPL(fuse_conn_init);
M
Miklos Szeredi 已提交
502

503 504
void fuse_conn_put(struct fuse_conn *fc)
{
505
	if (atomic_dec_and_test(&fc->count)) {
506 507
		if (fc->destroy_req)
			fuse_request_free(fc->destroy_req);
508
		mutex_destroy(&fc->inst_mutex);
T
Tejun Heo 已提交
509
		fc->release(fc);
510
	}
511
}
512
EXPORT_SYMBOL_GPL(fuse_conn_put);
513 514 515 516 517 518

struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
{
	atomic_inc(&fc->count);
	return fc;
}
519
EXPORT_SYMBOL_GPL(fuse_conn_get);
520

521
static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
M
Miklos Szeredi 已提交
522 523 524 525 526 527
{
	struct fuse_attr attr;
	memset(&attr, 0, sizeof(attr));

	attr.mode = mode;
	attr.ino = FUSE_ROOT_ID;
528
	attr.nlink = 1;
529
	return fuse_iget(sb, 1, 0, &attr, 0, 0);
M
Miklos Szeredi 已提交
530 531
}

M
Miklos Szeredi 已提交
532
struct fuse_inode_handle {
M
Miklos Szeredi 已提交
533 534 535 536 537 538 539
	u64 nodeid;
	u32 generation;
};

static struct dentry *fuse_get_dentry(struct super_block *sb,
				      struct fuse_inode_handle *handle)
{
540
	struct fuse_conn *fc = get_fuse_conn_super(sb);
M
Miklos Szeredi 已提交
541 542 543 544 545 546 547 548
	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);
549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569
	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;
	}
M
Miklos Szeredi 已提交
570 571 572 573
	err = -ESTALE;
	if (inode->i_generation != handle->generation)
		goto out_iput;

574 575
	entry = d_obtain_alias(inode);
	if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID) {
M
Miklos Szeredi 已提交
576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652
		entry->d_op = &fuse_dentry_operations;
		fuse_invalidate_entry_cache(entry);
	}

	return entry;

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

static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len,
			   int connectable)
{
	struct inode *inode = dentry->d_inode;
	bool encode_parent = connectable && !S_ISDIR(inode->i_mode);
	int len = encode_parent ? 6 : 3;
	u64 nodeid;
	u32 generation;

	if (*max_len < len)
		return  255;

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

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

	if (encode_parent) {
		struct inode *parent;

		spin_lock(&dentry->d_lock);
		parent = dentry->d_parent->d_inode;
		nodeid = get_fuse_inode(parent)->nodeid;
		generation = parent->i_generation;
		spin_unlock(&dentry->d_lock);

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

	*max_len = len;
	return encode_parent ? 0x82 : 0x81;
}

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);
}

653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669
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);
670 671 672
	if (err) {
		if (err == -ENOENT)
			return ERR_PTR(-ESTALE);
673 674
		return ERR_PTR(err);
	}
675 676 677

	parent = d_obtain_alias(inode);
	if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID) {
678 679 680 681 682 683
		parent->d_op = &fuse_dentry_operations;
		fuse_invalidate_entry_cache(parent);
	}

	return parent;
}
M
Miklos Szeredi 已提交
684 685 686 687 688

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,
689
	.get_parent	= fuse_get_parent,
M
Miklos Szeredi 已提交
690 691
};

692
static const struct super_operations fuse_super_operations = {
M
Miklos Szeredi 已提交
693 694 695
	.alloc_inode    = fuse_alloc_inode,
	.destroy_inode  = fuse_destroy_inode,
	.clear_inode	= fuse_clear_inode,
M
Miklos Szeredi 已提交
696
	.drop_inode	= generic_delete_inode,
697
	.remount_fs	= fuse_remount_fs,
M
Miklos Szeredi 已提交
698
	.put_super	= fuse_put_super,
699
	.umount_begin	= fuse_umount_begin,
700
	.statfs		= fuse_statfs,
M
Miklos Szeredi 已提交
701 702 703
	.show_options	= fuse_show_options,
};

704 705 706 707 708 709 710
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 {
711 712 713 714 715 716
		unsigned long ra_pages;

		if (arg->minor >= 6) {
			ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
			if (arg->flags & FUSE_ASYNC_READ)
				fc->async_read = 1;
717 718
			if (!(arg->flags & FUSE_POSIX_LOCKS))
				fc->no_lock = 1;
719 720
			if (arg->flags & FUSE_ATOMIC_O_TRUNC)
				fc->atomic_o_trunc = 1;
721 722 723 724 725
			if (arg->minor >= 9) {
				/* LOOKUP has dependency on proto version */
				if (arg->flags & FUSE_EXPORT_SUPPORT)
					fc->export_support = 1;
			}
726 727
			if (arg->flags & FUSE_BIG_WRITES)
				fc->big_writes = 1;
728 729
			if (arg->flags & FUSE_DONT_MASK)
				fc->dont_mask = 1;
730
		} else {
731
			ra_pages = fc->max_read / PAGE_CACHE_SIZE;
732 733
			fc->no_lock = 1;
		}
734 735

		fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
736 737
		fc->minor = arg->minor;
		fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
738
		fc->max_write = max_t(unsigned, 4096, fc->max_write);
739
		fc->conn_init = 1;
740
	}
741 742
	fc->blocked = 0;
	wake_up_all(&fc->blocked_waitq);
743 744
}

745
static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
746 747
{
	struct fuse_init_in *arg = &req->misc.init_in;
M
Miklos Szeredi 已提交
748

749 750
	arg->major = FUSE_KERNEL_VERSION;
	arg->minor = FUSE_KERNEL_MINOR_VERSION;
751
	arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
752
	arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
753
		FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK;
754 755 756 757 758 759 760 761 762 763 764 765
	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;
	/* Variable length arguement used for backward compatibility
	   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;
766
	fuse_request_send_background(fc, req);
767 768
}

T
Tejun Heo 已提交
769 770 771 772 773
static void fuse_free_conn(struct fuse_conn *fc)
{
	kfree(fc);
}

774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815
static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
{
	int err;

	fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
	fc->bdi.unplug_io_fn = default_unplug_io_fn;
	/* 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;
}

M
Miklos Szeredi 已提交
816 817 818 819 820 821
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;
822
	struct dentry *root_dentry;
823
	struct fuse_req *init_req;
M
Miklos Szeredi 已提交
824
	int err;
M
Miklos Szeredi 已提交
825
	int is_bdev = sb->s_bdev != NULL;
M
Miklos Szeredi 已提交
826

827
	err = -EINVAL;
828
	if (sb->s_flags & MS_MANDLOCK)
829
		goto err;
830

M
Miklos Szeredi 已提交
831
	if (!parse_fuse_opt((char *) data, &d, is_bdev))
832
		goto err;
M
Miklos Szeredi 已提交
833

M
Miklos Szeredi 已提交
834
	if (is_bdev) {
835
#ifdef CONFIG_BLOCK
836
		err = -EINVAL;
M
Miklos Szeredi 已提交
837
		if (!sb_set_blocksize(sb, d.blksize))
838
			goto err;
839
#endif
M
Miklos Szeredi 已提交
840 841 842 843
	} else {
		sb->s_blocksize = PAGE_CACHE_SIZE;
		sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
	}
M
Miklos Szeredi 已提交
844 845 846
	sb->s_magic = FUSE_SUPER_MAGIC;
	sb->s_op = &fuse_super_operations;
	sb->s_maxbytes = MAX_LFS_FILESIZE;
M
Miklos Szeredi 已提交
847
	sb->s_export_op = &fuse_export_operations;
M
Miklos Szeredi 已提交
848 849

	file = fget(d.fd);
850
	err = -EINVAL;
M
Miklos Szeredi 已提交
851
	if (!file)
852
		goto err;
M
Miklos Szeredi 已提交
853

854 855
	if (file->f_op != &fuse_dev_operations)
		goto err_fput;
M
Miklos Szeredi 已提交
856

857
	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
858 859 860
	err = -ENOMEM;
	if (!fc)
		goto err_fput;
M
Miklos Szeredi 已提交
861

862 863 864 865 866 867
	fuse_conn_init(fc);

	fc->dev = sb->s_dev;
	err = fuse_bdi_init(fc, sb);
	if (err)
		goto err_put_conn;
868

869 870 871 872 873
	/* Handle umasking inside the fuse code */
	if (sb->s_flags & MS_POSIXACL)
		fc->dont_mask = 1;
	sb->s_flags |= MS_POSIXACL;

T
Tejun Heo 已提交
874
	fc->release = fuse_free_conn;
M
Miklos Szeredi 已提交
875
	fc->flags = d.flags;
M
Miklos Szeredi 已提交
876
	fc->user_id = d.user_id;
877
	fc->group_id = d.group_id;
878
	fc->max_read = max_t(unsigned, 4096, d.max_read);
M
Miklos Szeredi 已提交
879

880 881 882
	/* Used by get_root_inode() */
	sb->s_fs_info = fc;

M
Miklos Szeredi 已提交
883
	err = -ENOMEM;
884
	root = fuse_get_root_inode(sb, d.rootmode);
885
	if (!root)
886
		goto err_put_conn;
M
Miklos Szeredi 已提交
887

888 889
	root_dentry = d_alloc_root(root);
	if (!root_dentry) {
M
Miklos Szeredi 已提交
890
		iput(root);
891
		goto err_put_conn;
M
Miklos Szeredi 已提交
892
	}
893

894 895 896 897
	init_req = fuse_request_alloc();
	if (!init_req)
		goto err_put_root;

898 899 900
	if (is_bdev) {
		fc->destroy_req = fuse_request_alloc();
		if (!fc->destroy_req)
J
Julia Lawall 已提交
901
			goto err_free_init_req;
902 903
	}

904
	mutex_lock(&fuse_mutex);
905 906
	err = -EINVAL;
	if (file->private_data)
907
		goto err_unlock;
908

909 910 911 912 913
	err = fuse_ctl_add_conn(fc);
	if (err)
		goto err_unlock;

	list_add_tail(&fc->entry, &fuse_conn_list);
914 915
	sb->s_root = root_dentry;
	fc->connected = 1;
916 917
	file->private_data = fuse_conn_get(fc);
	mutex_unlock(&fuse_mutex);
M
Miklos Szeredi 已提交
918 919 920 921 922 923
	/*
	 * 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);
924

925
	fuse_send_init(fc, init_req);
926

M
Miklos Szeredi 已提交
927 928
	return 0;

929 930
 err_unlock:
	mutex_unlock(&fuse_mutex);
J
Julia Lawall 已提交
931
 err_free_init_req:
932
	fuse_request_free(init_req);
933 934
 err_put_root:
	dput(root_dentry);
935
 err_put_conn:
936
	fuse_bdi_destroy(fc);
937
	fuse_conn_put(fc);
938 939 940
 err_fput:
	fput(file);
 err:
M
Miklos Szeredi 已提交
941 942 943
	return err;
}

944 945 946
static int fuse_get_sb(struct file_system_type *fs_type,
		       int flags, const char *dev_name,
		       void *raw_data, struct vfsmount *mnt)
M
Miklos Szeredi 已提交
947
{
948
	return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
M
Miklos Szeredi 已提交
949 950
}

951 952 953
static struct file_system_type fuse_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "fuse",
M
Miklos Szeredi 已提交
954
	.fs_flags	= FS_HAS_SUBTYPE,
955 956 957 958 959
	.get_sb		= fuse_get_sb,
	.kill_sb	= kill_anon_super,
};

#ifdef CONFIG_BLOCK
960 961 962 963 964 965 966 967 968 969 970 971 972
static int fuse_get_sb_blk(struct file_system_type *fs_type,
			   int flags, const char *dev_name,
			   void *raw_data, struct vfsmount *mnt)
{
	return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
			   mnt);
}

static struct file_system_type fuseblk_fs_type = {
	.owner		= THIS_MODULE,
	.name		= "fuseblk",
	.get_sb		= fuse_get_sb_blk,
	.kill_sb	= kill_block_super,
A
Alexey Dobriyan 已提交
973
	.fs_flags	= FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
974 975
};

976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995
static inline int register_fuseblk(void)
{
	return register_filesystem(&fuseblk_fs_type);
}

static inline void unregister_fuseblk(void)
{
	unregister_filesystem(&fuseblk_fs_type);
}
#else
static inline int register_fuseblk(void)
{
	return 0;
}

static inline void unregister_fuseblk(void)
{
}
#endif

996
static void fuse_inode_init_once(void *foo)
M
Miklos Szeredi 已提交
997
{
M
Miklos Szeredi 已提交
998
	struct inode *inode = foo;
M
Miklos Szeredi 已提交
999

C
Christoph Lameter 已提交
1000
	inode_init_once(inode);
M
Miklos Szeredi 已提交
1001 1002 1003 1004 1005 1006 1007 1008
}

static int __init fuse_fs_init(void)
{
	int err;

	err = register_filesystem(&fuse_fs_type);
	if (err)
1009 1010
		goto out;

1011
	err = register_fuseblk();
1012 1013 1014 1015 1016 1017
	if (err)
		goto out_unreg;

	fuse_inode_cachep = kmem_cache_create("fuse_inode",
					      sizeof(struct fuse_inode),
					      0, SLAB_HWCACHE_ALIGN,
1018
					      fuse_inode_init_once);
1019 1020 1021 1022 1023
	err = -ENOMEM;
	if (!fuse_inode_cachep)
		goto out_unreg2;

	return 0;
M
Miklos Szeredi 已提交
1024

1025
 out_unreg2:
1026
	unregister_fuseblk();
1027 1028 1029
 out_unreg:
	unregister_filesystem(&fuse_fs_type);
 out:
M
Miklos Szeredi 已提交
1030 1031 1032 1033 1034 1035
	return err;
}

static void fuse_fs_cleanup(void)
{
	unregister_filesystem(&fuse_fs_type);
1036
	unregister_fuseblk();
M
Miklos Szeredi 已提交
1037 1038 1039
	kmem_cache_destroy(fuse_inode_cachep);
}

1040 1041 1042
static struct kobject *fuse_kobj;
static struct kobject *connections_kobj;

1043 1044 1045 1046
static int fuse_sysfs_init(void)
{
	int err;

1047
	fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1048 1049
	if (!fuse_kobj) {
		err = -ENOMEM;
1050
		goto out_err;
1051
	}
1052

1053 1054 1055
	connections_kobj = kobject_create_and_add("connections", fuse_kobj);
	if (!connections_kobj) {
		err = -ENOMEM;
1056
		goto out_fuse_unregister;
1057
	}
1058 1059 1060 1061

	return 0;

 out_fuse_unregister:
1062
	kobject_put(fuse_kobj);
1063 1064 1065 1066 1067 1068
 out_err:
	return err;
}

static void fuse_sysfs_cleanup(void)
{
1069 1070
	kobject_put(connections_kobj);
	kobject_put(fuse_kobj);
1071 1072
}

M
Miklos Szeredi 已提交
1073 1074 1075 1076
static int __init fuse_init(void)
{
	int res;

M
Miklos Szeredi 已提交
1077
	printk(KERN_INFO "fuse init (API version %i.%i)\n",
M
Miklos Szeredi 已提交
1078 1079
	       FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);

1080
	INIT_LIST_HEAD(&fuse_conn_list);
M
Miklos Szeredi 已提交
1081 1082 1083 1084
	res = fuse_fs_init();
	if (res)
		goto err;

M
Miklos Szeredi 已提交
1085 1086 1087 1088
	res = fuse_dev_init();
	if (res)
		goto err_fs_cleanup;

1089 1090 1091 1092
	res = fuse_sysfs_init();
	if (res)
		goto err_dev_cleanup;

1093 1094 1095 1096
	res = fuse_ctl_init();
	if (res)
		goto err_sysfs_cleanup;

M
Miklos Szeredi 已提交
1097 1098
	return 0;

1099 1100
 err_sysfs_cleanup:
	fuse_sysfs_cleanup();
1101 1102
 err_dev_cleanup:
	fuse_dev_cleanup();
M
Miklos Szeredi 已提交
1103 1104
 err_fs_cleanup:
	fuse_fs_cleanup();
M
Miklos Szeredi 已提交
1105 1106 1107 1108 1109 1110 1111 1112
 err:
	return res;
}

static void __exit fuse_exit(void)
{
	printk(KERN_DEBUG "fuse exit\n");

1113
	fuse_ctl_cleanup();
1114
	fuse_sysfs_cleanup();
M
Miklos Szeredi 已提交
1115
	fuse_fs_cleanup();
M
Miklos Szeredi 已提交
1116
	fuse_dev_cleanup();
M
Miklos Szeredi 已提交
1117 1118 1119 1120
}

module_init(fuse_init);
module_exit(fuse_exit);