fs/fuse/inode.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU GPL.
   6   See the file COPYING.
   7 */
   8
   9 #include "fuse_i.h"
  10
  11 #include <linux/pagemap.h>
  12 #include <linux/slab.h>
  13 #include <linux/file.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/moduleparam.h>
  18 #include <linux/parser.h>
  19 #include <linux/statfs.h>
  20 #include <linux/random.h>
  21 #include <linux/sched.h>
  22 #include <linux/exportfs.h>
  23
  24 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
  25 MODULE_DESCRIPTION("Filesystem in Userspace");
  26 MODULE_LICENSE("GPL");
  27
  28 static struct kmem_cache *fuse_inode_cachep;
  29 struct list_head fuse_conn_list;
  30 DEFINE_MUTEX(fuse_mutex);
  31
  32 static int set_global_limit(const char *val, struct kernel_param *kp);
  33
  34 unsigned max_user_bgreq;
  35 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
  36                   &max_user_bgreq, 0644);
  37 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
  38 MODULE_PARM_DESC(max_user_bgreq,
  39  "Global limit for the maximum number of backgrounded requests an "
  40  "unprivileged user can set");
  41
  42 unsigned max_user_congthresh;
  43 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
  44                   &max_user_congthresh, 0644);
  45 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
  46 MODULE_PARM_DESC(max_user_congthresh,
  47  "Global limit for the maximum congestion threshold an "
  48  "unprivileged user can set");
  49
  50 #define FUSE_SUPER_MAGIC 0x65735546
  51
  52 #define FUSE_DEFAULT_BLKSIZE 512
  53
  54 /** Maximum number of outstanding background requests */
  55 #define FUSE_DEFAULT_MAX_BACKGROUND 12
  56
  57 /** Congestion starts at 75% of maximum */
  58 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
  59
  60 struct fuse_mount_data {
  61         int fd;
  62         unsigned rootmode;
  63         kuid_t user_id;
  64         kgid_t group_id;
  65         unsigned fd_present:1;
  66         unsigned rootmode_present:1;
  67         unsigned user_id_present:1;
  68         unsigned group_id_present:1;
  69         unsigned flags;
  70         unsigned max_read;
  71         unsigned blksize;
  72 };
  73
  74 struct fuse_forget_link *fuse_alloc_forget(void)
  75 {
  76         return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
  77 }
  78
  79 static struct inode *fuse_alloc_inode(struct super_block *sb)
  80 {
  81         struct inode *inode;
  82         struct fuse_inode *fi;
  83
  84         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
  85         if (!inode)
  86                 return NULL;
  87
  88         fi = get_fuse_inode(inode);
  89         fi->i_time = 0;
  90         fi->nodeid = 0;
  91         fi->nlookup = 0;
  92         fi->attr_version = 0;
  93         fi->writectr = 0;
  94         fi->orig_ino = 0;
  95         fi->state = 0;
  96         INIT_LIST_HEAD(&fi->write_files);
  97         INIT_LIST_HEAD(&fi->queued_writes);
  98         INIT_LIST_HEAD(&fi->writepages);
  99         init_waitqueue_head(&fi->page_waitq);
 100         fi->forget = fuse_alloc_forget();
 101         if (!fi->forget) {
 102                 kmem_cache_free(fuse_inode_cachep, inode);
 103                 return NULL;
 104         }
 105
 106         return inode;
 107 }
 108
 109 static void fuse_i_callback(struct rcu_head *head)
 110 {
 111         struct inode *inode = container_of(head, struct inode, i_rcu);
 112         kmem_cache_free(fuse_inode_cachep, inode);
 113 }
 114
 115 static void fuse_destroy_inode(struct inode *inode)
 116 {
 117         struct fuse_inode *fi = get_fuse_inode(inode);
 118         BUG_ON(!list_empty(&fi->write_files));
 119         BUG_ON(!list_empty(&fi->queued_writes));
 120         kfree(fi->forget);
 121         call_rcu(&inode->i_rcu, fuse_i_callback);
 122 }
 123
 124 static void fuse_evict_inode(struct inode *inode)
 125 {
 126         truncate_inode_pages_final(&inode->i_data);
 127         clear_inode(inode);
 128         if (inode->i_sb->s_flags & MS_ACTIVE) {
 129                 struct fuse_conn *fc = get_fuse_conn(inode);
 130                 struct fuse_inode *fi = get_fuse_inode(inode);
 131                 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
 132                 fi->forget = NULL;
 133         }
 134 }
 135
 136 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 137 {
 138         sync_filesystem(sb);
 139         if (*flags & MS_MANDLOCK)
 140                 return -EINVAL;
 141
 142         return 0;
 143 }
 144
 145 /*
 146  * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
 147  * so that it will fit.
 148  */
 149 static ino_t fuse_squash_ino(u64 ino64)
 150 {
 151         ino_t ino = (ino_t) ino64;
 152         if (sizeof(ino_t) < sizeof(u64))
 153                 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
 154         return ino;
 155 }
 156
 157 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 158                                    u64 attr_valid)
 159 {
 160         struct fuse_conn *fc = get_fuse_conn(inode);
 161         struct fuse_inode *fi = get_fuse_inode(inode);
 162
 163         fi->attr_version = ++fc->attr_version;
 164         fi->i_time = attr_valid;
 165
 166         inode->i_ino     = fuse_squash_ino(attr->ino);
 167         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 168         set_nlink(inode, attr->nlink);
 169         inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
 170         inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
 171         inode->i_blocks  = attr->blocks;
 172         inode->i_atime.tv_sec   = attr->atime;
 173         inode->i_atime.tv_nsec  = attr->atimensec;
 174         /* mtime from server may be stale due to local buffered write */
 175         if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
 176                 inode->i_mtime.tv_sec   = attr->mtime;
 177                 inode->i_mtime.tv_nsec  = attr->mtimensec;
 178                 inode->i_ctime.tv_sec   = attr->ctime;
 179                 inode->i_ctime.tv_nsec  = attr->ctimensec;
 180         }
 181
 182         if (attr->blksize != 0)
 183                 inode->i_blkbits = ilog2(attr->blksize);
 184         else
 185                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
 186
 187         /*
 188          * Don't set the sticky bit in i_mode, unless we want the VFS
 189          * to check permissions.  This prevents failures due to the
 190          * check in may_delete().
 191          */
 192         fi->orig_i_mode = inode->i_mode;
 193         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
 194                 inode->i_mode &= ~S_ISVTX;
 195
 196         fi->orig_ino = attr->ino;
 197 }
 198
 199 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 200                             u64 attr_valid, u64 attr_version)
 201 {
 202         struct fuse_conn *fc = get_fuse_conn(inode);
 203         struct fuse_inode *fi = get_fuse_inode(inode);
 204         bool is_wb = fc->writeback_cache;
 205         loff_t oldsize;
 206         struct timespec old_mtime;
 207
 208         spin_lock(&fc->lock);
 209         if ((attr_version != 0 && fi->attr_version > attr_version) ||
 210             test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
 211                 spin_unlock(&fc->lock);
 212                 return;
 213         }
 214
 215         old_mtime = inode->i_mtime;
 216         fuse_change_attributes_common(inode, attr, attr_valid);
 217
 218         oldsize = inode->i_size;
 219         /*
 220          * In case of writeback_cache enabled, the cached writes beyond EOF
 221          * extend local i_size without keeping userspace server in sync. So,
 222          * attr->size coming from server can be stale. We cannot trust it.
 223          */
 224         if (!is_wb || !S_ISREG(inode->i_mode))
 225                 i_size_write(inode, attr->size);
 226         spin_unlock(&fc->lock);
 227
 228         if (!is_wb && S_ISREG(inode->i_mode)) {
 229                 bool inval = false;
 230
 231                 if (oldsize != attr->size) {
 232                         truncate_pagecache(inode, attr->size);
 233                         inval = true;
 234                 } else if (fc->auto_inval_data) {
 235                         struct timespec new_mtime = {
 236                                 .tv_sec = attr->mtime,
 237                                 .tv_nsec = attr->mtimensec,
 238                         };
 239
 240                         /*
 241                          * Auto inval mode also checks and invalidates if mtime
 242                          * has changed.
 243                          */
 244                         if (!timespec_equal(&old_mtime, &new_mtime))
 245                                 inval = true;
 246                 }
 247
 248                 if (inval)
 249                         invalidate_inode_pages2(inode->i_mapping);
 250         }
 251 }
 252
 253 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 254 {
 255         inode->i_mode = attr->mode & S_IFMT;
 256         inode->i_size = attr->size;
 257         inode->i_mtime.tv_sec  = attr->mtime;
 258         inode->i_mtime.tv_nsec = attr->mtimensec;
 259         inode->i_ctime.tv_sec  = attr->ctime;
 260         inode->i_ctime.tv_nsec = attr->ctimensec;
 261         if (S_ISREG(inode->i_mode)) {
 262                 fuse_init_common(inode);
 263                 fuse_init_file_inode(inode);
 264         } else if (S_ISDIR(inode->i_mode))
 265                 fuse_init_dir(inode);
 266         else if (S_ISLNK(inode->i_mode))
 267                 fuse_init_symlink(inode);
 268         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 269                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 270                 fuse_init_common(inode);
 271                 init_special_inode(inode, inode->i_mode,
 272                                    new_decode_dev(attr->rdev));
 273         } else
 274                 BUG();
 275 }
 276
 277 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 278 {
 279         u64 nodeid = *(u64 *) _nodeidp;
 280         if (get_node_id(inode) == nodeid)
 281                 return 1;
 282         else
 283                 return 0;
 284 }
 285
 286 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 287 {
 288         u64 nodeid = *(u64 *) _nodeidp;
 289         get_fuse_inode(inode)->nodeid = nodeid;
 290         return 0;
 291 }
 292
 293 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 294                         int generation, struct fuse_attr *attr,
 295                         u64 attr_valid, u64 attr_version)
 296 {
 297         struct inode *inode;
 298         struct fuse_inode *fi;
 299         struct fuse_conn *fc = get_fuse_conn_super(sb);
 300
 301  retry:
 302         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 303         if (!inode)
 304                 return NULL;
 305
 306         if ((inode->i_state & I_NEW)) {
 307                 inode->i_flags |= S_NOATIME;
 308                 if (!fc->writeback_cache || !S_ISREG(attr->mode))
 309                         inode->i_flags |= S_NOCMTIME;
 310                 inode->i_generation = generation;
 311                 inode->i_data.backing_dev_info = &fc->bdi;
 312                 fuse_init_inode(inode, attr);
 313                 unlock_new_inode(inode);
 314         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 315                 /* Inode has changed type, any I/O on the old should fail */
 316                 make_bad_inode(inode);
 317                 iput(inode);
 318                 goto retry;
 319         }
 320
 321         fi = get_fuse_inode(inode);
 322         spin_lock(&fc->lock);
 323         fi->nlookup++;
 324         spin_unlock(&fc->lock);
 325         fuse_change_attributes(inode, attr, attr_valid, attr_version);
 326
 327         return inode;
 328 }
 329
 330 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 331                              loff_t offset, loff_t len)
 332 {
 333         struct inode *inode;
 334         pgoff_t pg_start;
 335         pgoff_t pg_end;
 336
 337         inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
 338         if (!inode)
 339                 return -ENOENT;
 340
 341         fuse_invalidate_attr(inode);
 342         if (offset >= 0) {
 343                 pg_start = offset >> PAGE_CACHE_SHIFT;
 344                 if (len <= 0)
 345                         pg_end = -1;
 346                 else
 347                         pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
 348                 invalidate_inode_pages2_range(inode->i_mapping,
 349                                               pg_start, pg_end);
 350         }
 351         iput(inode);
 352         return 0;
 353 }
 354
 355 static void fuse_umount_begin(struct super_block *sb)
 356 {
 357         fuse_abort_conn(get_fuse_conn_super(sb));
 358 }
 359
 360 static void fuse_send_destroy(struct fuse_conn *fc)
 361 {
 362         struct fuse_req *req = fc->destroy_req;
 363         if (req && fc->conn_init) {
 364                 fc->destroy_req = NULL;
 365                 req->in.h.opcode = FUSE_DESTROY;
 366                 req->force = 1;
 367                 req->background = 0;
 368                 fuse_request_send(fc, req);
 369                 fuse_put_request(fc, req);
 370         }
 371 }
 372
 373 static void fuse_bdi_destroy(struct fuse_conn *fc)
 374 {
 375         if (fc->bdi_initialized)
 376                 bdi_destroy(&fc->bdi);
 377 }
 378
 379 static void fuse_put_super(struct super_block *sb)
 380 {
 381         struct fuse_conn *fc = get_fuse_conn_super(sb);
 382
 383         fuse_send_destroy(fc);
 384
 385         fuse_abort_conn(fc);
 386         mutex_lock(&fuse_mutex);
 387         list_del(&fc->entry);
 388         fuse_ctl_remove_conn(fc);
 389         mutex_unlock(&fuse_mutex);
 390         fuse_bdi_destroy(fc);
 391
 392         fuse_conn_put(fc);
 393 }
 394
 395 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 396 {
 397         stbuf->f_type    = FUSE_SUPER_MAGIC;
 398         stbuf->f_bsize   = attr->bsize;
 399         stbuf->f_frsize  = attr->frsize;
 400         stbuf->f_blocks  = attr->blocks;
 401         stbuf->f_bfree   = attr->bfree;
 402         stbuf->f_bavail  = attr->bavail;
 403         stbuf->f_files   = attr->files;
 404         stbuf->f_ffree   = attr->ffree;
 405         stbuf->f_namelen = attr->namelen;
 406         /* fsid is left zero */
 407 }
 408
 409 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 410 {
 411         struct super_block *sb = dentry->d_sb;
 412         struct fuse_conn *fc = get_fuse_conn_super(sb);
 413         FUSE_ARGS(args);
 414         struct fuse_statfs_out outarg;
 415         int err;
 416
 417         if (!fuse_allow_current_process(fc)) {
 418                 buf->f_type = FUSE_SUPER_MAGIC;
 419                 return 0;
 420         }
 421
 422         memset(&outarg, 0, sizeof(outarg));
 423         args.in.numargs = 0;
 424         args.in.h.opcode = FUSE_STATFS;
 425         args.in.h.nodeid = get_node_id(dentry->d_inode);
 426         args.out.numargs = 1;
 427         args.out.args[0].size = sizeof(outarg);
 428         args.out.args[0].value = &outarg;
 429         err = fuse_simple_request(fc, &args);
 430         if (!err)
 431                 convert_fuse_statfs(buf, &outarg.st);
 432         return err;
 433 }
 434
 435 enum {
 436         OPT_FD,
 437         OPT_ROOTMODE,
 438         OPT_USER_ID,
 439         OPT_GROUP_ID,
 440         OPT_DEFAULT_PERMISSIONS,
 441         OPT_ALLOW_OTHER,
 442         OPT_MAX_READ,
 443         OPT_BLKSIZE,
 444         OPT_ERR
 445 };
 446
 447 static const match_table_t tokens = {
 448         {OPT_FD,                        "fd=%u"},
 449         {OPT_ROOTMODE,                  "rootmode=%o"},
 450         {OPT_USER_ID,                   "user_id=%u"},
 451         {OPT_GROUP_ID,                  "group_id=%u"},
 452         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 453         {OPT_ALLOW_OTHER,               "allow_other"},
 454         {OPT_MAX_READ,                  "max_read=%u"},
 455         {OPT_BLKSIZE,                   "blksize=%u"},
 456         {OPT_ERR,                       NULL}
 457 };
 458
 459 static int fuse_match_uint(substring_t *s, unsigned int *res)
 460 {
 461         int err = -ENOMEM;
 462         char *buf = match_strdup(s);
 463         if (buf) {
 464                 err = kstrtouint(buf, 10, res);
 465                 kfree(buf);
 466         }
 467         return err;
 468 }
 469
 470 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 471 {
 472         char *p;
 473         memset(d, 0, sizeof(struct fuse_mount_data));
 474         d->max_read = ~0;
 475         d->blksize = FUSE_DEFAULT_BLKSIZE;
 476
 477         while ((p = strsep(&opt, ",")) != NULL) {
 478                 int token;
 479                 int value;
 480                 unsigned uv;
 481                 substring_t args[MAX_OPT_ARGS];
 482                 if (!*p)
 483                         continue;
 484
 485                 token = match_token(p, tokens, args);
 486                 switch (token) {
 487                 case OPT_FD:
 488                         if (match_int(&args[0], &value))
 489                                 return 0;
 490                         d->fd = value;
 491                         d->fd_present = 1;
 492                         break;
 493
 494                 case OPT_ROOTMODE:
 495                         if (match_octal(&args[0], &value))
 496                                 return 0;
 497                         if (!fuse_valid_type(value))
 498                                 return 0;
 499                         d->rootmode = value;
 500                         d->rootmode_present = 1;
 501                         break;
 502
 503                 case OPT_USER_ID:
 504                         if (fuse_match_uint(&args[0], &uv))
 505                                 return 0;
 506                         d->user_id = make_kuid(current_user_ns(), uv);
 507                         if (!uid_valid(d->user_id))
 508                                 return 0;
 509                         d->user_id_present = 1;
 510                         break;
 511
 512                 case OPT_GROUP_ID:
 513                         if (fuse_match_uint(&args[0], &uv))
 514                                 return 0;
 515                         d->group_id = make_kgid(current_user_ns(), uv);
 516                         if (!gid_valid(d->group_id))
 517                                 return 0;
 518                         d->group_id_present = 1;
 519                         break;
 520
 521                 case OPT_DEFAULT_PERMISSIONS:
 522                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 523                         break;
 524
 525                 case OPT_ALLOW_OTHER:
 526                         d->flags |= FUSE_ALLOW_OTHER;
 527                         break;
 528
 529                 case OPT_MAX_READ:
 530                         if (match_int(&args[0], &value))
 531                                 return 0;
 532                         d->max_read = value;
 533                         break;
 534
 535                 case OPT_BLKSIZE:
 536                         if (!is_bdev || match_int(&args[0], &value))
 537                                 return 0;
 538                         d->blksize = value;
 539                         break;
 540
 541                 default:
 542                         return 0;
 543                 }
 544         }
 545
 546         if (!d->fd_present || !d->rootmode_present ||
 547             !d->user_id_present || !d->group_id_present)
 548                 return 0;
 549
 550         return 1;
 551 }
 552
 553 static int fuse_show_options(struct seq_file *m, struct dentry *root)
 554 {
 555         struct super_block *sb = root->d_sb;
 556         struct fuse_conn *fc = get_fuse_conn_super(sb);
 557
 558         seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
 559         seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
 560         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 561                 seq_puts(m, ",default_permissions");
 562         if (fc->flags & FUSE_ALLOW_OTHER)
 563                 seq_puts(m, ",allow_other");
 564         if (fc->max_read != ~0)
 565                 seq_printf(m, ",max_read=%u", fc->max_read);
 566         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 567                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
 568         return 0;
 569 }
 570
 571 void fuse_conn_init(struct fuse_conn *fc)
 572 {
 573         memset(fc, 0, sizeof(*fc));
 574         spin_lock_init(&fc->lock);
 575         init_rwsem(&fc->killsb);
 576         atomic_set(&fc->count, 1);
 577         init_waitqueue_head(&fc->waitq);
 578         init_waitqueue_head(&fc->blocked_waitq);
 579         init_waitqueue_head(&fc->reserved_req_waitq);
 580         INIT_LIST_HEAD(&fc->pending);
 581         INIT_LIST_HEAD(&fc->processing);
 582         INIT_LIST_HEAD(&fc->io);
 583         INIT_LIST_HEAD(&fc->interrupts);
 584         INIT_LIST_HEAD(&fc->bg_queue);
 585         INIT_LIST_HEAD(&fc->entry);
 586         fc->forget_list_tail = &fc->forget_list_head;
 587         atomic_set(&fc->num_waiting, 0);
 588         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
 589         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
 590         fc->khctr = 0;
 591         fc->polled_files = RB_ROOT;
 592         fc->reqctr = 0;
 593         fc->blocked = 0;
 594         fc->initialized = 0;
 595         fc->attr_version = 1;
 596         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 597 }
 598 EXPORT_SYMBOL_GPL(fuse_conn_init);
 599
 600 void fuse_conn_put(struct fuse_conn *fc)
 601 {
 602         if (atomic_dec_and_test(&fc->count)) {
 603                 if (fc->destroy_req)
 604                         fuse_request_free(fc->destroy_req);
 605                 fc->release(fc);
 606         }
 607 }
 608 EXPORT_SYMBOL_GPL(fuse_conn_put);
 609
 610 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 611 {
 612         atomic_inc(&fc->count);
 613         return fc;
 614 }
 615 EXPORT_SYMBOL_GPL(fuse_conn_get);
 616
 617 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 618 {
 619         struct fuse_attr attr;
 620         memset(&attr, 0, sizeof(attr));
 621
 622         attr.mode = mode;
 623         attr.ino = FUSE_ROOT_ID;
 624         attr.nlink = 1;
 625         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 626 }
 627
 628 struct fuse_inode_handle {
 629         u64 nodeid;
 630         u32 generation;
 631 };
 632
 633 static struct dentry *fuse_get_dentry(struct super_block *sb,
 634                                       struct fuse_inode_handle *handle)
 635 {
 636         struct fuse_conn *fc = get_fuse_conn_super(sb);
 637         struct inode *inode;
 638         struct dentry *entry;
 639         int err = -ESTALE;
 640
 641         if (handle->nodeid == 0)
 642                 goto out_err;
 643
 644         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
 645         if (!inode) {
 646                 struct fuse_entry_out outarg;
 647                 struct qstr name;
 648
 649                 if (!fc->export_support)
 650                         goto out_err;
 651
 652                 name.len = 1;
 653                 name.name = ".";
 654                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
 655                                        &inode);
 656                 if (err && err != -ENOENT)
 657                         goto out_err;
 658                 if (err || !inode) {
 659                         err = -ESTALE;
 660                         goto out_err;
 661                 }
 662                 err = -EIO;
 663                 if (get_node_id(inode) != handle->nodeid)
 664                         goto out_iput;
 665         }
 666         err = -ESTALE;
 667         if (inode->i_generation != handle->generation)
 668                 goto out_iput;
 669
 670         entry = d_obtain_alias(inode);
 671         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
 672                 fuse_invalidate_entry_cache(entry);
 673
 674         return entry;
 675
 676  out_iput:
 677         iput(inode);
 678  out_err:
 679         return ERR_PTR(err);
 680 }
 681
 682 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 683                            struct inode *parent)
 684 {
 685         int len = parent ? 6 : 3;
 686         u64 nodeid;
 687         u32 generation;
 688
 689         if (*max_len < len) {
 690                 *max_len = len;
 691                 return  FILEID_INVALID;
 692         }
 693
 694         nodeid = get_fuse_inode(inode)->nodeid;
 695         generation = inode->i_generation;
 696
 697         fh[0] = (u32)(nodeid >> 32);
 698         fh[1] = (u32)(nodeid & 0xffffffff);
 699         fh[2] = generation;
 700
 701         if (parent) {
 702                 nodeid = get_fuse_inode(parent)->nodeid;
 703                 generation = parent->i_generation;
 704
 705                 fh[3] = (u32)(nodeid >> 32);
 706                 fh[4] = (u32)(nodeid & 0xffffffff);
 707                 fh[5] = generation;
 708         }
 709
 710         *max_len = len;
 711         return parent ? 0x82 : 0x81;
 712 }
 713
 714 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
 715                 struct fid *fid, int fh_len, int fh_type)
 716 {
 717         struct fuse_inode_handle handle;
 718
 719         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
 720                 return NULL;
 721
 722         handle.nodeid = (u64) fid->raw[0] << 32;
 723         handle.nodeid |= (u64) fid->raw[1];
 724         handle.generation = fid->raw[2];
 725         return fuse_get_dentry(sb, &handle);
 726 }
 727
 728 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
 729                 struct fid *fid, int fh_len, int fh_type)
 730 {
 731         struct fuse_inode_handle parent;
 732
 733         if (fh_type != 0x82 || fh_len < 6)
 734                 return NULL;
 735
 736         parent.nodeid = (u64) fid->raw[3] << 32;
 737         parent.nodeid |= (u64) fid->raw[4];
 738         parent.generation = fid->raw[5];
 739         return fuse_get_dentry(sb, &parent);
 740 }
 741
 742 static struct dentry *fuse_get_parent(struct dentry *child)
 743 {
 744         struct inode *child_inode = child->d_inode;
 745         struct fuse_conn *fc = get_fuse_conn(child_inode);
 746         struct inode *inode;
 747         struct dentry *parent;
 748         struct fuse_entry_out outarg;
 749         struct qstr name;
 750         int err;
 751
 752         if (!fc->export_support)
 753                 return ERR_PTR(-ESTALE);
 754
 755         name.len = 2;
 756         name.name = "..";
 757         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
 758                                &name, &outarg, &inode);
 759         if (err) {
 760                 if (err == -ENOENT)
 761                         return ERR_PTR(-ESTALE);
 762                 return ERR_PTR(err);
 763         }
 764
 765         parent = d_obtain_alias(inode);
 766         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
 767                 fuse_invalidate_entry_cache(parent);
 768
 769         return parent;
 770 }
 771
 772 static const struct export_operations fuse_export_operations = {
 773         .fh_to_dentry   = fuse_fh_to_dentry,
 774         .fh_to_parent   = fuse_fh_to_parent,
 775         .encode_fh      = fuse_encode_fh,
 776         .get_parent     = fuse_get_parent,
 777 };
 778
 779 static const struct super_operations fuse_super_operations = {
 780         .alloc_inode    = fuse_alloc_inode,
 781         .destroy_inode  = fuse_destroy_inode,
 782         .evict_inode    = fuse_evict_inode,
 783         .write_inode    = fuse_write_inode,
 784         .drop_inode     = generic_delete_inode,
 785         .remount_fs     = fuse_remount_fs,
 786         .put_super      = fuse_put_super,
 787         .umount_begin   = fuse_umount_begin,
 788         .statfs         = fuse_statfs,
 789         .show_options   = fuse_show_options,
 790 };
 791
 792 static void sanitize_global_limit(unsigned *limit)
 793 {
 794         if (*limit == 0)
 795                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
 796                          sizeof(struct fuse_req);
 797
 798         if (*limit >= 1 << 16)
 799                 *limit = (1 << 16) - 1;
 800 }
 801
 802 static int set_global_limit(const char *val, struct kernel_param *kp)
 803 {
 804         int rv;
 805
 806         rv = param_set_uint(val, kp);
 807         if (rv)
 808                 return rv;
 809
 810         sanitize_global_limit((unsigned *)kp->arg);
 811
 812         return 0;
 813 }
 814
 815 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
 816 {
 817         int cap_sys_admin = capable(CAP_SYS_ADMIN);
 818
 819         if (arg->minor < 13)
 820                 return;
 821
 822         sanitize_global_limit(&max_user_bgreq);
 823         sanitize_global_limit(&max_user_congthresh);
 824
 825         if (arg->max_background) {
 826                 fc->max_background = arg->max_background;
 827
 828                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
 829                         fc->max_background = max_user_bgreq;
 830         }
 831         if (arg->congestion_threshold) {
 832                 fc->congestion_threshold = arg->congestion_threshold;
 833
 834                 if (!cap_sys_admin &&
 835                     fc->congestion_threshold > max_user_congthresh)
 836                         fc->congestion_threshold = max_user_congthresh;
 837         }
 838 }
 839
 840 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 841 {
 842         struct fuse_init_out *arg = &req->misc.init_out;
 843
 844         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 845                 fc->conn_error = 1;
 846         else {
 847                 unsigned long ra_pages;
 848
 849                 process_init_limits(fc, arg);
 850
 851                 if (arg->minor >= 6) {
 852                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 853                         if (arg->flags & FUSE_ASYNC_READ)
 854                                 fc->async_read = 1;
 855                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 856                                 fc->no_lock = 1;
 857                         if (arg->minor >= 17) {
 858                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
 859                                         fc->no_flock = 1;
 860                         } else {
 861                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
 862                                         fc->no_flock = 1;
 863                         }
 864                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 865                                 fc->atomic_o_trunc = 1;
 866                         if (arg->minor >= 9) {
 867                                 /* LOOKUP has dependency on proto version */
 868                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
 869                                         fc->export_support = 1;
 870                         }
 871                         if (arg->flags & FUSE_BIG_WRITES)
 872                                 fc->big_writes = 1;
 873                         if (arg->flags & FUSE_DONT_MASK)
 874                                 fc->dont_mask = 1;
 875                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
 876                                 fc->auto_inval_data = 1;
 877                         if (arg->flags & FUSE_DO_READDIRPLUS) {
 878                                 fc->do_readdirplus = 1;
 879                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
 880                                         fc->readdirplus_auto = 1;
 881                         }
 882                         if (arg->flags & FUSE_ASYNC_DIO)
 883                                 fc->async_dio = 1;
 884                         if (arg->flags & FUSE_WRITEBACK_CACHE)
 885                                 fc->writeback_cache = 1;
 886                         if (arg->time_gran && arg->time_gran <= 1000000000)
 887                                 fc->sb->s_time_gran = arg->time_gran;
 888                 } else {
 889                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 890                         fc->no_lock = 1;
 891                         fc->no_flock = 1;
 892                 }
 893
 894                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 895                 fc->minor = arg->minor;
 896                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 897                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
 898                 fc->conn_init = 1;
 899         }
 900         fuse_set_initialized(fc);
 901         wake_up_all(&fc->blocked_waitq);
 902 }
 903
 904 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 905 {
 906         struct fuse_init_in *arg = &req->misc.init_in;
 907
 908         arg->major = FUSE_KERNEL_VERSION;
 909         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 910         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 911         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
 912                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
 913                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
 914                 FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
 915                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
 916                 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT;
 917         req->in.h.opcode = FUSE_INIT;
 918         req->in.numargs = 1;
 919         req->in.args[0].size = sizeof(*arg);
 920         req->in.args[0].value = arg;
 921         req->out.numargs = 1;
 922         /* Variable length argument used for backward compatibility
 923            with interface version < 7.5.  Rest of init_out is zeroed
 924            by do_get_request(), so a short reply is not a problem */
 925         req->out.argvar = 1;
 926         req->out.args[0].size = sizeof(struct fuse_init_out);
 927         req->out.args[0].value = &req->misc.init_out;
 928         req->end = process_init_reply;
 929         fuse_request_send_background(fc, req);
 930 }
 931
 932 static void fuse_free_conn(struct fuse_conn *fc)
 933 {
 934         kfree_rcu(fc, rcu);
 935 }
 936
 937 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 938 {
 939         int err;
 940
 941         fc->bdi.name = "fuse";
 942         fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 943         /* fuse does it's own writeback accounting */
 944         fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 945
 946         err = bdi_init(&fc->bdi);
 947         if (err)
 948                 return err;
 949
 950         fc->bdi_initialized = 1;
 951
 952         if (sb->s_bdev) {
 953                 err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
 954                                     MAJOR(fc->dev), MINOR(fc->dev));
 955         } else {
 956                 err = bdi_register_dev(&fc->bdi, fc->dev);
 957         }
 958
 959         if (err)
 960                 return err;
 961
 962         /*
 963          * For a single fuse filesystem use max 1% of dirty +
 964          * writeback threshold.
 965          *
 966          * This gives about 1M of write buffer for memory maps on a
 967          * machine with 1G and 10% dirty_ratio, which should be more
 968          * than enough.
 969          *
 970          * Privileged users can raise it by writing to
 971          *
 972          *    /sys/class/bdi/<bdi>/max_ratio
 973          */
 974         bdi_set_max_ratio(&fc->bdi, 1);
 975
 976         return 0;
 977 }
 978
 979 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 980 {
 981         struct fuse_conn *fc;
 982         struct inode *root;
 983         struct fuse_mount_data d;
 984         struct file *file;
 985         struct dentry *root_dentry;
 986         struct fuse_req *init_req;
 987         int err;
 988         int is_bdev = sb->s_bdev != NULL;
 989
 990         err = -EINVAL;
 991         if (sb->s_flags & MS_MANDLOCK)
 992                 goto err;
 993
 994         sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
 995
 996         if (!parse_fuse_opt(data, &d, is_bdev))
 997                 goto err;
 998
 999         if (is_bdev) {
1000 #ifdef CONFIG_BLOCK
1001                 err = -EINVAL;
1002                 if (!sb_set_blocksize(sb, d.blksize))
1003                         goto err;
1004 #endif
1005         } else {
1006                 sb->s_blocksize = PAGE_CACHE_SIZE;
1007                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1008         }
1009         sb->s_magic = FUSE_SUPER_MAGIC;
1010         sb->s_op = &fuse_super_operations;
1011         sb->s_maxbytes = MAX_LFS_FILESIZE;
1012         sb->s_time_gran = 1;
1013         sb->s_export_op = &fuse_export_operations;
1014
1015         file = fget(d.fd);
1016         err = -EINVAL;
1017         if (!file)
1018                 goto err;
1019
1020         if ((file->f_op != &fuse_dev_operations) ||
1021             (file->f_cred->user_ns != &init_user_ns))
1022                 goto err_fput;
1023
1024         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1025         err = -ENOMEM;
1026         if (!fc)
1027                 goto err_fput;
1028
1029         fuse_conn_init(fc);
1030
1031         fc->dev = sb->s_dev;
1032         fc->sb = sb;
1033         err = fuse_bdi_init(fc, sb);
1034         if (err)
1035                 goto err_put_conn;
1036
1037         sb->s_bdi = &fc->bdi;
1038
1039         /* Handle umasking inside the fuse code */
1040         if (sb->s_flags & MS_POSIXACL)
1041                 fc->dont_mask = 1;
1042         sb->s_flags |= MS_POSIXACL;
1043
1044         fc->release = fuse_free_conn;
1045         fc->flags = d.flags;
1046         fc->user_id = d.user_id;
1047         fc->group_id = d.group_id;
1048         fc->max_read = max_t(unsigned, 4096, d.max_read);
1049
1050         /* Used by get_root_inode() */
1051         sb->s_fs_info = fc;
1052
1053         err = -ENOMEM;
1054         root = fuse_get_root_inode(sb, d.rootmode);
1055         root_dentry = d_make_root(root);
1056         if (!root_dentry)
1057                 goto err_put_conn;
1058         /* only now - we want root dentry with NULL ->d_op */
1059         sb->s_d_op = &fuse_dentry_operations;
1060
1061         init_req = fuse_request_alloc(0);
1062         if (!init_req)
1063                 goto err_put_root;
1064         init_req->background = 1;
1065
1066         if (is_bdev) {
1067                 fc->destroy_req = fuse_request_alloc(0);
1068                 if (!fc->destroy_req)
1069                         goto err_free_init_req;
1070         }
1071
1072         mutex_lock(&fuse_mutex);
1073         err = -EINVAL;
1074         if (file->private_data)
1075                 goto err_unlock;
1076
1077         err = fuse_ctl_add_conn(fc);
1078         if (err)
1079                 goto err_unlock;
1080
1081         list_add_tail(&fc->entry, &fuse_conn_list);
1082         sb->s_root = root_dentry;
1083         fc->connected = 1;
1084         file->private_data = fuse_conn_get(fc);
1085         mutex_unlock(&fuse_mutex);
1086         /*
1087          * atomic_dec_and_test() in fput() provides the necessary
1088          * memory barrier for file->private_data to be visible on all
1089          * CPUs after this
1090          */
1091         fput(file);
1092
1093         fuse_send_init(fc, init_req);
1094
1095         return 0;
1096
1097  err_unlock:
1098         mutex_unlock(&fuse_mutex);
1099  err_free_init_req:
1100         fuse_request_free(init_req);
1101  err_put_root:
1102         dput(root_dentry);
1103  err_put_conn:
1104         fuse_bdi_destroy(fc);
1105         fuse_conn_put(fc);
1106  err_fput:
1107         fput(file);
1108  err:
1109         return err;
1110 }
1111
1112 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1113                        int flags, const char *dev_name,
1114                        void *raw_data)
1115 {
1116         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1117 }
1118
1119 static void fuse_kill_sb_anon(struct super_block *sb)
1120 {
1121         struct fuse_conn *fc = get_fuse_conn_super(sb);
1122
1123         if (fc) {
1124                 down_write(&fc->killsb);
1125                 fc->sb = NULL;
1126                 up_write(&fc->killsb);
1127         }
1128
1129         kill_anon_super(sb);
1130 }
1131
1132 static struct file_system_type fuse_fs_type = {
1133         .owner          = THIS_MODULE,
1134         .name           = "fuse",
1135         .fs_flags       = FS_HAS_SUBTYPE,
1136         .mount          = fuse_mount,
1137         .kill_sb        = fuse_kill_sb_anon,
1138 };
1139 MODULE_ALIAS_FS("fuse");
1140
1141 #ifdef CONFIG_BLOCK
1142 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1143                            int flags, const char *dev_name,
1144                            void *raw_data)
1145 {
1146         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1147 }
1148
1149 static void fuse_kill_sb_blk(struct super_block *sb)
1150 {
1151         struct fuse_conn *fc = get_fuse_conn_super(sb);
1152
1153         if (fc) {
1154                 down_write(&fc->killsb);
1155                 fc->sb = NULL;
1156                 up_write(&fc->killsb);
1157         }
1158
1159         kill_block_super(sb);
1160 }
1161
1162 static struct file_system_type fuseblk_fs_type = {
1163         .owner          = THIS_MODULE,
1164         .name           = "fuseblk",
1165         .mount          = fuse_mount_blk,
1166         .kill_sb        = fuse_kill_sb_blk,
1167         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1168 };
1169 MODULE_ALIAS_FS("fuseblk");
1170
1171 static inline int register_fuseblk(void)
1172 {
1173         return register_filesystem(&fuseblk_fs_type);
1174 }
1175
1176 static inline void unregister_fuseblk(void)
1177 {
1178         unregister_filesystem(&fuseblk_fs_type);
1179 }
1180 #else
1181 static inline int register_fuseblk(void)
1182 {
1183         return 0;
1184 }
1185
1186 static inline void unregister_fuseblk(void)
1187 {
1188 }
1189 #endif
1190
1191 static void fuse_inode_init_once(void *foo)
1192 {
1193         struct inode *inode = foo;
1194
1195         inode_init_once(inode);
1196 }
1197
1198 static int __init fuse_fs_init(void)
1199 {
1200         int err;
1201
1202         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1203                                               sizeof(struct fuse_inode),
1204                                               0, SLAB_HWCACHE_ALIGN,
1205                                               fuse_inode_init_once);
1206         err = -ENOMEM;
1207         if (!fuse_inode_cachep)
1208                 goto out;
1209
1210         err = register_fuseblk();
1211         if (err)
1212                 goto out2;
1213
1214         err = register_filesystem(&fuse_fs_type);
1215         if (err)
1216                 goto out3;
1217
1218         return 0;
1219
1220  out3:
1221         unregister_fuseblk();
1222  out2:
1223         kmem_cache_destroy(fuse_inode_cachep);
1224  out:
1225         return err;
1226 }
1227
1228 static void fuse_fs_cleanup(void)
1229 {
1230         unregister_filesystem(&fuse_fs_type);
1231         unregister_fuseblk();
1232
1233         /*
1234          * Make sure all delayed rcu free inodes are flushed before we
1235          * destroy cache.
1236          */
1237         rcu_barrier();
1238         kmem_cache_destroy(fuse_inode_cachep);
1239 }
1240
1241 static struct kobject *fuse_kobj;
1242 static struct kobject *connections_kobj;
1243
1244 static int fuse_sysfs_init(void)
1245 {
1246         int err;
1247
1248         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1249         if (!fuse_kobj) {
1250                 err = -ENOMEM;
1251                 goto out_err;
1252         }
1253
1254         connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1255         if (!connections_kobj) {
1256                 err = -ENOMEM;
1257                 goto out_fuse_unregister;
1258         }
1259
1260         return 0;
1261
1262  out_fuse_unregister:
1263         kobject_put(fuse_kobj);
1264  out_err:
1265         return err;
1266 }
1267
1268 static void fuse_sysfs_cleanup(void)
1269 {
1270         kobject_put(connections_kobj);
1271         kobject_put(fuse_kobj);
1272 }
1273
1274 static int __init fuse_init(void)
1275 {
1276         int res;
1277
1278         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1279                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1280
1281         INIT_LIST_HEAD(&fuse_conn_list);
1282         res = fuse_fs_init();
1283         if (res)
1284                 goto err;
1285
1286         res = fuse_dev_init();
1287         if (res)
1288                 goto err_fs_cleanup;
1289
1290         res = fuse_sysfs_init();
1291         if (res)
1292                 goto err_dev_cleanup;
1293
1294         res = fuse_ctl_init();
1295         if (res)
1296                 goto err_sysfs_cleanup;
1297
1298         sanitize_global_limit(&max_user_bgreq);
1299         sanitize_global_limit(&max_user_congthresh);
1300
1301         return 0;
1302
1303  err_sysfs_cleanup:
1304         fuse_sysfs_cleanup();
1305  err_dev_cleanup:
1306         fuse_dev_cleanup();
1307  err_fs_cleanup:
1308         fuse_fs_cleanup();
1309  err:
1310         return res;
1311 }
1312
1313 static void __exit fuse_exit(void)
1314 {
1315         printk(KERN_DEBUG "fuse exit\n");
1316
1317         fuse_ctl_cleanup();
1318         fuse_sysfs_cleanup();
1319         fuse_fs_cleanup();
1320         fuse_dev_cleanup();
1321 }
1322
1323 module_init(fuse_init);
1324 module_exit(fuse_exit);