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         }
 179         inode->i_ctime.tv_sec   = attr->ctime;
 180         inode->i_ctime.tv_nsec  = attr->ctimensec;
 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         if (S_ISREG(inode->i_mode)) {
 260                 fuse_init_common(inode);
 261                 fuse_init_file_inode(inode);
 262         } else if (S_ISDIR(inode->i_mode))
 263                 fuse_init_dir(inode);
 264         else if (S_ISLNK(inode->i_mode))
 265                 fuse_init_symlink(inode);
 266         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 267                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 268                 fuse_init_common(inode);
 269                 init_special_inode(inode, inode->i_mode,
 270                                    new_decode_dev(attr->rdev));
 271         } else
 272                 BUG();
 273 }
 274
 275 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 276 {
 277         u64 nodeid = *(u64 *) _nodeidp;
 278         if (get_node_id(inode) == nodeid)
 279                 return 1;
 280         else
 281                 return 0;
 282 }
 283
 284 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 285 {
 286         u64 nodeid = *(u64 *) _nodeidp;
 287         get_fuse_inode(inode)->nodeid = nodeid;
 288         return 0;
 289 }
 290
 291 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 292                         int generation, struct fuse_attr *attr,
 293                         u64 attr_valid, u64 attr_version)
 294 {
 295         struct inode *inode;
 296         struct fuse_inode *fi;
 297         struct fuse_conn *fc = get_fuse_conn_super(sb);
 298
 299  retry:
 300         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 301         if (!inode)
 302                 return NULL;
 303
 304         if ((inode->i_state & I_NEW)) {
 305                 inode->i_flags |= S_NOATIME;
 306                 if (!fc->writeback_cache || !S_ISREG(inode->i_mode))
 307                         inode->i_flags |= S_NOCMTIME;
 308                 inode->i_generation = generation;
 309                 inode->i_data.backing_dev_info = &fc->bdi;
 310                 fuse_init_inode(inode, attr);
 311                 unlock_new_inode(inode);
 312         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 313                 /* Inode has changed type, any I/O on the old should fail */
 314                 make_bad_inode(inode);
 315                 iput(inode);
 316                 goto retry;
 317         }
 318
 319         fi = get_fuse_inode(inode);
 320         spin_lock(&fc->lock);
 321         fi->nlookup++;
 322         spin_unlock(&fc->lock);
 323         fuse_change_attributes(inode, attr, attr_valid, attr_version);
 324
 325         return inode;
 326 }
 327
 328 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 329                              loff_t offset, loff_t len)
 330 {
 331         struct inode *inode;
 332         pgoff_t pg_start;
 333         pgoff_t pg_end;
 334
 335         inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
 336         if (!inode)
 337                 return -ENOENT;
 338
 339         fuse_invalidate_attr(inode);
 340         if (offset >= 0) {
 341                 pg_start = offset >> PAGE_CACHE_SHIFT;
 342                 if (len <= 0)
 343                         pg_end = -1;
 344                 else
 345                         pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
 346                 invalidate_inode_pages2_range(inode->i_mapping,
 347                                               pg_start, pg_end);
 348         }
 349         iput(inode);
 350         return 0;
 351 }
 352
 353 static void fuse_umount_begin(struct super_block *sb)
 354 {
 355         fuse_abort_conn(get_fuse_conn_super(sb));
 356 }
 357
 358 static void fuse_send_destroy(struct fuse_conn *fc)
 359 {
 360         struct fuse_req *req = fc->destroy_req;
 361         if (req && fc->conn_init) {
 362                 fc->destroy_req = NULL;
 363                 req->in.h.opcode = FUSE_DESTROY;
 364                 req->force = 1;
 365                 req->background = 0;
 366                 fuse_request_send(fc, req);
 367                 fuse_put_request(fc, req);
 368         }
 369 }
 370
 371 static void fuse_bdi_destroy(struct fuse_conn *fc)
 372 {
 373         if (fc->bdi_initialized)
 374                 bdi_destroy(&fc->bdi);
 375 }
 376
 377 void fuse_conn_kill(struct fuse_conn *fc)
 378 {
 379         spin_lock(&fc->lock);
 380         fc->connected = 0;
 381         fc->blocked = 0;
 382         fc->initialized = 1;
 383         spin_unlock(&fc->lock);
 384         /* Flush all readers on this fs */
 385         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 386         wake_up_all(&fc->waitq);
 387         wake_up_all(&fc->blocked_waitq);
 388         wake_up_all(&fc->reserved_req_waitq);
 389 }
 390 EXPORT_SYMBOL_GPL(fuse_conn_kill);
 391
 392 static void fuse_put_super(struct super_block *sb)
 393 {
 394         struct fuse_conn *fc = get_fuse_conn_super(sb);
 395
 396         fuse_send_destroy(fc);
 397
 398         fuse_conn_kill(fc);
 399         mutex_lock(&fuse_mutex);
 400         list_del(&fc->entry);
 401         fuse_ctl_remove_conn(fc);
 402         mutex_unlock(&fuse_mutex);
 403         fuse_bdi_destroy(fc);
 404
 405         fuse_conn_put(fc);
 406 }
 407
 408 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 409 {
 410         stbuf->f_type    = FUSE_SUPER_MAGIC;
 411         stbuf->f_bsize   = attr->bsize;
 412         stbuf->f_frsize  = attr->frsize;
 413         stbuf->f_blocks  = attr->blocks;
 414         stbuf->f_bfree   = attr->bfree;
 415         stbuf->f_bavail  = attr->bavail;
 416         stbuf->f_files   = attr->files;
 417         stbuf->f_ffree   = attr->ffree;
 418         stbuf->f_namelen = attr->namelen;
 419         /* fsid is left zero */
 420 }
 421
 422 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 423 {
 424         struct super_block *sb = dentry->d_sb;
 425         struct fuse_conn *fc = get_fuse_conn_super(sb);
 426         struct fuse_req *req;
 427         struct fuse_statfs_out outarg;
 428         int err;
 429
 430         if (!fuse_allow_current_process(fc)) {
 431                 buf->f_type = FUSE_SUPER_MAGIC;
 432                 return 0;
 433         }
 434
 435         req = fuse_get_req_nopages(fc);
 436         if (IS_ERR(req))
 437                 return PTR_ERR(req);
 438
 439         memset(&outarg, 0, sizeof(outarg));
 440         req->in.numargs = 0;
 441         req->in.h.opcode = FUSE_STATFS;
 442         req->in.h.nodeid = get_node_id(dentry->d_inode);
 443         req->out.numargs = 1;
 444         req->out.args[0].size =
 445                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 446         req->out.args[0].value = &outarg;
 447         fuse_request_send(fc, req);
 448         err = req->out.h.error;
 449         if (!err)
 450                 convert_fuse_statfs(buf, &outarg.st);
 451         fuse_put_request(fc, req);
 452         return err;
 453 }
 454
 455 enum {
 456         OPT_FD,
 457         OPT_ROOTMODE,
 458         OPT_USER_ID,
 459         OPT_GROUP_ID,
 460         OPT_DEFAULT_PERMISSIONS,
 461         OPT_ALLOW_OTHER,
 462         OPT_MAX_READ,
 463         OPT_BLKSIZE,
 464         OPT_ERR
 465 };
 466
 467 static const match_table_t tokens = {
 468         {OPT_FD,                        "fd=%u"},
 469         {OPT_ROOTMODE,                  "rootmode=%o"},
 470         {OPT_USER_ID,                   "user_id=%u"},
 471         {OPT_GROUP_ID,                  "group_id=%u"},
 472         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 473         {OPT_ALLOW_OTHER,               "allow_other"},
 474         {OPT_MAX_READ,                  "max_read=%u"},
 475         {OPT_BLKSIZE,                   "blksize=%u"},
 476         {OPT_ERR,                       NULL}
 477 };
 478
 479 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 480 {
 481         char *p;
 482         memset(d, 0, sizeof(struct fuse_mount_data));
 483         d->max_read = ~0;
 484         d->blksize = FUSE_DEFAULT_BLKSIZE;
 485
 486         while ((p = strsep(&opt, ",")) != NULL) {
 487                 int token;
 488                 int value;
 489                 substring_t args[MAX_OPT_ARGS];
 490                 if (!*p)
 491                         continue;
 492
 493                 token = match_token(p, tokens, args);
 494                 switch (token) {
 495                 case OPT_FD:
 496                         if (match_int(&args[0], &value))
 497                                 return 0;
 498                         d->fd = value;
 499                         d->fd_present = 1;
 500                         break;
 501
 502                 case OPT_ROOTMODE:
 503                         if (match_octal(&args[0], &value))
 504                                 return 0;
 505                         if (!fuse_valid_type(value))
 506                                 return 0;
 507                         d->rootmode = value;
 508                         d->rootmode_present = 1;
 509                         break;
 510
 511                 case OPT_USER_ID:
 512                         if (match_int(&args[0], &value))
 513                                 return 0;
 514                         d->user_id = make_kuid(current_user_ns(), value);
 515                         if (!uid_valid(d->user_id))
 516                                 return 0;
 517                         d->user_id_present = 1;
 518                         break;
 519
 520                 case OPT_GROUP_ID:
 521                         if (match_int(&args[0], &value))
 522                                 return 0;
 523                         d->group_id = make_kgid(current_user_ns(), value);
 524                         if (!gid_valid(d->group_id))
 525                                 return 0;
 526                         d->group_id_present = 1;
 527                         break;
 528
 529                 case OPT_DEFAULT_PERMISSIONS:
 530                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 531                         break;
 532
 533                 case OPT_ALLOW_OTHER:
 534                         d->flags |= FUSE_ALLOW_OTHER;
 535                         break;
 536
 537                 case OPT_MAX_READ:
 538                         if (match_int(&args[0], &value))
 539                                 return 0;
 540                         d->max_read = value;
 541                         break;
 542
 543                 case OPT_BLKSIZE:
 544                         if (!is_bdev || match_int(&args[0], &value))
 545                                 return 0;
 546                         d->blksize = value;
 547                         break;
 548
 549                 default:
 550                         return 0;
 551                 }
 552         }
 553
 554         if (!d->fd_present || !d->rootmode_present ||
 555             !d->user_id_present || !d->group_id_present)
 556                 return 0;
 557
 558         return 1;
 559 }
 560
 561 static int fuse_show_options(struct seq_file *m, struct dentry *root)
 562 {
 563         struct super_block *sb = root->d_sb;
 564         struct fuse_conn *fc = get_fuse_conn_super(sb);
 565
 566         seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
 567         seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
 568         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 569                 seq_puts(m, ",default_permissions");
 570         if (fc->flags & FUSE_ALLOW_OTHER)
 571                 seq_puts(m, ",allow_other");
 572         if (fc->max_read != ~0)
 573                 seq_printf(m, ",max_read=%u", fc->max_read);
 574         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 575                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
 576         return 0;
 577 }
 578
 579 void fuse_conn_init(struct fuse_conn *fc)
 580 {
 581         memset(fc, 0, sizeof(*fc));
 582         spin_lock_init(&fc->lock);
 583         init_rwsem(&fc->killsb);
 584         atomic_set(&fc->count, 1);
 585         init_waitqueue_head(&fc->waitq);
 586         init_waitqueue_head(&fc->blocked_waitq);
 587         init_waitqueue_head(&fc->reserved_req_waitq);
 588         INIT_LIST_HEAD(&fc->pending);
 589         INIT_LIST_HEAD(&fc->processing);
 590         INIT_LIST_HEAD(&fc->io);
 591         INIT_LIST_HEAD(&fc->interrupts);
 592         INIT_LIST_HEAD(&fc->bg_queue);
 593         INIT_LIST_HEAD(&fc->entry);
 594         fc->forget_list_tail = &fc->forget_list_head;
 595         atomic_set(&fc->num_waiting, 0);
 596         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
 597         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
 598         fc->khctr = 0;
 599         fc->polled_files = RB_ROOT;
 600         fc->reqctr = 0;
 601         fc->blocked = 0;
 602         fc->initialized = 0;
 603         fc->attr_version = 1;
 604         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 605 }
 606 EXPORT_SYMBOL_GPL(fuse_conn_init);
 607
 608 void fuse_conn_put(struct fuse_conn *fc)
 609 {
 610         if (atomic_dec_and_test(&fc->count)) {
 611                 if (fc->destroy_req)
 612                         fuse_request_free(fc->destroy_req);
 613                 fc->release(fc);
 614         }
 615 }
 616 EXPORT_SYMBOL_GPL(fuse_conn_put);
 617
 618 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 619 {
 620         atomic_inc(&fc->count);
 621         return fc;
 622 }
 623 EXPORT_SYMBOL_GPL(fuse_conn_get);
 624
 625 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 626 {
 627         struct fuse_attr attr;
 628         memset(&attr, 0, sizeof(attr));
 629
 630         attr.mode = mode;
 631         attr.ino = FUSE_ROOT_ID;
 632         attr.nlink = 1;
 633         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 634 }
 635
 636 struct fuse_inode_handle {
 637         u64 nodeid;
 638         u32 generation;
 639 };
 640
 641 static struct dentry *fuse_get_dentry(struct super_block *sb,
 642                                       struct fuse_inode_handle *handle)
 643 {
 644         struct fuse_conn *fc = get_fuse_conn_super(sb);
 645         struct inode *inode;
 646         struct dentry *entry;
 647         int err = -ESTALE;
 648
 649         if (handle->nodeid == 0)
 650                 goto out_err;
 651
 652         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
 653         if (!inode) {
 654                 struct fuse_entry_out outarg;
 655                 struct qstr name;
 656
 657                 if (!fc->export_support)
 658                         goto out_err;
 659
 660                 name.len = 1;
 661                 name.name = ".";
 662                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
 663                                        &inode);
 664                 if (err && err != -ENOENT)
 665                         goto out_err;
 666                 if (err || !inode) {
 667                         err = -ESTALE;
 668                         goto out_err;
 669                 }
 670                 err = -EIO;
 671                 if (get_node_id(inode) != handle->nodeid)
 672                         goto out_iput;
 673         }
 674         err = -ESTALE;
 675         if (inode->i_generation != handle->generation)
 676                 goto out_iput;
 677
 678         entry = d_obtain_alias(inode);
 679         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
 680                 fuse_invalidate_entry_cache(entry);
 681
 682         return entry;
 683
 684  out_iput:
 685         iput(inode);
 686  out_err:
 687         return ERR_PTR(err);
 688 }
 689
 690 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 691                            struct inode *parent)
 692 {
 693         int len = parent ? 6 : 3;
 694         u64 nodeid;
 695         u32 generation;
 696
 697         if (*max_len < len) {
 698                 *max_len = len;
 699                 return  FILEID_INVALID;
 700         }
 701
 702         nodeid = get_fuse_inode(inode)->nodeid;
 703         generation = inode->i_generation;
 704
 705         fh[0] = (u32)(nodeid >> 32);
 706         fh[1] = (u32)(nodeid & 0xffffffff);
 707         fh[2] = generation;
 708
 709         if (parent) {
 710                 nodeid = get_fuse_inode(parent)->nodeid;
 711                 generation = parent->i_generation;
 712
 713                 fh[3] = (u32)(nodeid >> 32);
 714                 fh[4] = (u32)(nodeid & 0xffffffff);
 715                 fh[5] = generation;
 716         }
 717
 718         *max_len = len;
 719         return parent ? 0x82 : 0x81;
 720 }
 721
 722 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
 723                 struct fid *fid, int fh_len, int fh_type)
 724 {
 725         struct fuse_inode_handle handle;
 726
 727         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
 728                 return NULL;
 729
 730         handle.nodeid = (u64) fid->raw[0] << 32;
 731         handle.nodeid |= (u64) fid->raw[1];
 732         handle.generation = fid->raw[2];
 733         return fuse_get_dentry(sb, &handle);
 734 }
 735
 736 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
 737                 struct fid *fid, int fh_len, int fh_type)
 738 {
 739         struct fuse_inode_handle parent;
 740
 741         if (fh_type != 0x82 || fh_len < 6)
 742                 return NULL;
 743
 744         parent.nodeid = (u64) fid->raw[3] << 32;
 745         parent.nodeid |= (u64) fid->raw[4];
 746         parent.generation = fid->raw[5];
 747         return fuse_get_dentry(sb, &parent);
 748 }
 749
 750 static struct dentry *fuse_get_parent(struct dentry *child)
 751 {
 752         struct inode *child_inode = child->d_inode;
 753         struct fuse_conn *fc = get_fuse_conn(child_inode);
 754         struct inode *inode;
 755         struct dentry *parent;
 756         struct fuse_entry_out outarg;
 757         struct qstr name;
 758         int err;
 759
 760         if (!fc->export_support)
 761                 return ERR_PTR(-ESTALE);
 762
 763         name.len = 2;
 764         name.name = "..";
 765         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
 766                                &name, &outarg, &inode);
 767         if (err) {
 768                 if (err == -ENOENT)
 769                         return ERR_PTR(-ESTALE);
 770                 return ERR_PTR(err);
 771         }
 772
 773         parent = d_obtain_alias(inode);
 774         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
 775                 fuse_invalidate_entry_cache(parent);
 776
 777         return parent;
 778 }
 779
 780 static const struct export_operations fuse_export_operations = {
 781         .fh_to_dentry   = fuse_fh_to_dentry,
 782         .fh_to_parent   = fuse_fh_to_parent,
 783         .encode_fh      = fuse_encode_fh,
 784         .get_parent     = fuse_get_parent,
 785 };
 786
 787 static const struct super_operations fuse_super_operations = {
 788         .alloc_inode    = fuse_alloc_inode,
 789         .destroy_inode  = fuse_destroy_inode,
 790         .evict_inode    = fuse_evict_inode,
 791         .drop_inode     = generic_delete_inode,
 792         .remount_fs     = fuse_remount_fs,
 793         .put_super      = fuse_put_super,
 794         .umount_begin   = fuse_umount_begin,
 795         .statfs         = fuse_statfs,
 796         .show_options   = fuse_show_options,
 797 };
 798
 799 static void sanitize_global_limit(unsigned *limit)
 800 {
 801         if (*limit == 0)
 802                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
 803                          sizeof(struct fuse_req);
 804
 805         if (*limit >= 1 << 16)
 806                 *limit = (1 << 16) - 1;
 807 }
 808
 809 static int set_global_limit(const char *val, struct kernel_param *kp)
 810 {
 811         int rv;
 812
 813         rv = param_set_uint(val, kp);
 814         if (rv)
 815                 return rv;
 816
 817         sanitize_global_limit((unsigned *)kp->arg);
 818
 819         return 0;
 820 }
 821
 822 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
 823 {
 824         int cap_sys_admin = capable(CAP_SYS_ADMIN);
 825
 826         if (arg->minor < 13)
 827                 return;
 828
 829         sanitize_global_limit(&max_user_bgreq);
 830         sanitize_global_limit(&max_user_congthresh);
 831
 832         if (arg->max_background) {
 833                 fc->max_background = arg->max_background;
 834
 835                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
 836                         fc->max_background = max_user_bgreq;
 837         }
 838         if (arg->congestion_threshold) {
 839                 fc->congestion_threshold = arg->congestion_threshold;
 840
 841                 if (!cap_sys_admin &&
 842                     fc->congestion_threshold > max_user_congthresh)
 843                         fc->congestion_threshold = max_user_congthresh;
 844         }
 845 }
 846
 847 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 848 {
 849         struct fuse_init_out *arg = &req->misc.init_out;
 850
 851         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 852                 fc->conn_error = 1;
 853         else {
 854                 unsigned long ra_pages;
 855
 856                 process_init_limits(fc, arg);
 857
 858                 if (arg->minor >= 6) {
 859                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 860                         if (arg->flags & FUSE_ASYNC_READ)
 861                                 fc->async_read = 1;
 862                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 863                                 fc->no_lock = 1;
 864                         if (arg->minor >= 17) {
 865                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
 866                                         fc->no_flock = 1;
 867                         } else {
 868                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
 869                                         fc->no_flock = 1;
 870                         }
 871                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 872                                 fc->atomic_o_trunc = 1;
 873                         if (arg->minor >= 9) {
 874                                 /* LOOKUP has dependency on proto version */
 875                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
 876                                         fc->export_support = 1;
 877                         }
 878                         if (arg->flags & FUSE_BIG_WRITES)
 879                                 fc->big_writes = 1;
 880                         if (arg->flags & FUSE_DONT_MASK)
 881                                 fc->dont_mask = 1;
 882                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
 883                                 fc->auto_inval_data = 1;
 884                         if (arg->flags & FUSE_DO_READDIRPLUS) {
 885                                 fc->do_readdirplus = 1;
 886                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
 887                                         fc->readdirplus_auto = 1;
 888                         }
 889                         if (arg->flags & FUSE_ASYNC_DIO)
 890                                 fc->async_dio = 1;
 891                         if (arg->flags & FUSE_WRITEBACK_CACHE)
 892                                 fc->writeback_cache = 1;
 893                 } else {
 894                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 895                         fc->no_lock = 1;
 896                         fc->no_flock = 1;
 897                 }
 898
 899                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 900                 fc->minor = arg->minor;
 901                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 902                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
 903                 fc->conn_init = 1;
 904         }
 905         fc->initialized = 1;
 906         wake_up_all(&fc->blocked_waitq);
 907 }
 908
 909 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 910 {
 911         struct fuse_init_in *arg = &req->misc.init_in;
 912
 913         arg->major = FUSE_KERNEL_VERSION;
 914         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 915         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 916         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
 917                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
 918                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
 919                 FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
 920                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
 921                 FUSE_WRITEBACK_CACHE;
 922         req->in.h.opcode = FUSE_INIT;
 923         req->in.numargs = 1;
 924         req->in.args[0].size = sizeof(*arg);
 925         req->in.args[0].value = arg;
 926         req->out.numargs = 1;
 927         /* Variable length argument used for backward compatibility
 928            with interface version < 7.5.  Rest of init_out is zeroed
 929            by do_get_request(), so a short reply is not a problem */
 930         req->out.argvar = 1;
 931         req->out.args[0].size = sizeof(struct fuse_init_out);
 932         req->out.args[0].value = &req->misc.init_out;
 933         req->end = process_init_reply;
 934         fuse_request_send_background(fc, req);
 935 }
 936
 937 static void fuse_free_conn(struct fuse_conn *fc)
 938 {
 939         kfree_rcu(fc, rcu);
 940 }
 941
 942 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 943 {
 944         int err;
 945
 946         fc->bdi.name = "fuse";
 947         fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 948         /* fuse does it's own writeback accounting */
 949         fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 950
 951         err = bdi_init(&fc->bdi);
 952         if (err)
 953                 return err;
 954
 955         fc->bdi_initialized = 1;
 956
 957         if (sb->s_bdev) {
 958                 err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
 959                                     MAJOR(fc->dev), MINOR(fc->dev));
 960         } else {
 961                 err = bdi_register_dev(&fc->bdi, fc->dev);
 962         }
 963
 964         if (err)
 965                 return err;
 966
 967         /*
 968          * For a single fuse filesystem use max 1% of dirty +
 969          * writeback threshold.
 970          *
 971          * This gives about 1M of write buffer for memory maps on a
 972          * machine with 1G and 10% dirty_ratio, which should be more
 973          * than enough.
 974          *
 975          * Privileged users can raise it by writing to
 976          *
 977          *    /sys/class/bdi/<bdi>/max_ratio
 978          */
 979         bdi_set_max_ratio(&fc->bdi, 1);
 980
 981         return 0;
 982 }
 983
 984 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 985 {
 986         struct fuse_conn *fc;
 987         struct inode *root;
 988         struct fuse_mount_data d;
 989         struct file *file;
 990         struct dentry *root_dentry;
 991         struct fuse_req *init_req;
 992         int err;
 993         int is_bdev = sb->s_bdev != NULL;
 994
 995         err = -EINVAL;
 996         if (sb->s_flags & MS_MANDLOCK)
 997                 goto err;
 998
 999         sb->s_flags &= ~MS_NOSEC;
1000
1001         if (!parse_fuse_opt((char *) data, &d, is_bdev))
1002                 goto err;
1003
1004         if (is_bdev) {
1005 #ifdef CONFIG_BLOCK
1006                 err = -EINVAL;
1007                 if (!sb_set_blocksize(sb, d.blksize))
1008                         goto err;
1009 #endif
1010         } else {
1011                 sb->s_blocksize = PAGE_CACHE_SIZE;
1012                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1013         }
1014         sb->s_magic = FUSE_SUPER_MAGIC;
1015         sb->s_op = &fuse_super_operations;
1016         sb->s_maxbytes = MAX_LFS_FILESIZE;
1017         sb->s_time_gran = 1;
1018         sb->s_export_op = &fuse_export_operations;
1019
1020         file = fget(d.fd);
1021         err = -EINVAL;
1022         if (!file)
1023                 goto err;
1024
1025         if ((file->f_op != &fuse_dev_operations) ||
1026             (file->f_cred->user_ns != &init_user_ns))
1027                 goto err_fput;
1028
1029         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1030         err = -ENOMEM;
1031         if (!fc)
1032                 goto err_fput;
1033
1034         fuse_conn_init(fc);
1035
1036         fc->dev = sb->s_dev;
1037         fc->sb = sb;
1038         err = fuse_bdi_init(fc, sb);
1039         if (err)
1040                 goto err_put_conn;
1041
1042         sb->s_bdi = &fc->bdi;
1043
1044         /* Handle umasking inside the fuse code */
1045         if (sb->s_flags & MS_POSIXACL)
1046                 fc->dont_mask = 1;
1047         sb->s_flags |= MS_POSIXACL;
1048
1049         fc->release = fuse_free_conn;
1050         fc->flags = d.flags;
1051         fc->user_id = d.user_id;
1052         fc->group_id = d.group_id;
1053         fc->max_read = max_t(unsigned, 4096, d.max_read);
1054
1055         /* Used by get_root_inode() */
1056         sb->s_fs_info = fc;
1057
1058         err = -ENOMEM;
1059         root = fuse_get_root_inode(sb, d.rootmode);
1060         root_dentry = d_make_root(root);
1061         if (!root_dentry)
1062                 goto err_put_conn;
1063         /* only now - we want root dentry with NULL ->d_op */
1064         sb->s_d_op = &fuse_dentry_operations;
1065
1066         init_req = fuse_request_alloc(0);
1067         if (!init_req)
1068                 goto err_put_root;
1069         init_req->background = 1;
1070
1071         if (is_bdev) {
1072                 fc->destroy_req = fuse_request_alloc(0);
1073                 if (!fc->destroy_req)
1074                         goto err_free_init_req;
1075         }
1076
1077         mutex_lock(&fuse_mutex);
1078         err = -EINVAL;
1079         if (file->private_data)
1080                 goto err_unlock;
1081
1082         err = fuse_ctl_add_conn(fc);
1083         if (err)
1084                 goto err_unlock;
1085
1086         list_add_tail(&fc->entry, &fuse_conn_list);
1087         sb->s_root = root_dentry;
1088         fc->connected = 1;
1089         file->private_data = fuse_conn_get(fc);
1090         mutex_unlock(&fuse_mutex);
1091         /*
1092          * atomic_dec_and_test() in fput() provides the necessary
1093          * memory barrier for file->private_data to be visible on all
1094          * CPUs after this
1095          */
1096         fput(file);
1097
1098         fuse_send_init(fc, init_req);
1099
1100         return 0;
1101
1102  err_unlock:
1103         mutex_unlock(&fuse_mutex);
1104  err_free_init_req:
1105         fuse_request_free(init_req);
1106  err_put_root:
1107         dput(root_dentry);
1108  err_put_conn:
1109         fuse_bdi_destroy(fc);
1110         fuse_conn_put(fc);
1111  err_fput:
1112         fput(file);
1113  err:
1114         return err;
1115 }
1116
1117 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1118                        int flags, const char *dev_name,
1119                        void *raw_data)
1120 {
1121         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1122 }
1123
1124 static void fuse_kill_sb_anon(struct super_block *sb)
1125 {
1126         struct fuse_conn *fc = get_fuse_conn_super(sb);
1127
1128         if (fc) {
1129                 down_write(&fc->killsb);
1130                 fc->sb = NULL;
1131                 up_write(&fc->killsb);
1132         }
1133
1134         kill_anon_super(sb);
1135 }
1136
1137 static struct file_system_type fuse_fs_type = {
1138         .owner          = THIS_MODULE,
1139         .name           = "fuse",
1140         .fs_flags       = FS_HAS_SUBTYPE,
1141         .mount          = fuse_mount,
1142         .kill_sb        = fuse_kill_sb_anon,
1143 };
1144 MODULE_ALIAS_FS("fuse");
1145
1146 #ifdef CONFIG_BLOCK
1147 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1148                            int flags, const char *dev_name,
1149                            void *raw_data)
1150 {
1151         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1152 }
1153
1154 static void fuse_kill_sb_blk(struct super_block *sb)
1155 {
1156         struct fuse_conn *fc = get_fuse_conn_super(sb);
1157
1158         if (fc) {
1159                 down_write(&fc->killsb);
1160                 fc->sb = NULL;
1161                 up_write(&fc->killsb);
1162         }
1163
1164         kill_block_super(sb);
1165 }
1166
1167 static struct file_system_type fuseblk_fs_type = {
1168         .owner          = THIS_MODULE,
1169         .name           = "fuseblk",
1170         .mount          = fuse_mount_blk,
1171         .kill_sb        = fuse_kill_sb_blk,
1172         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1173 };
1174 MODULE_ALIAS_FS("fuseblk");
1175
1176 static inline int register_fuseblk(void)
1177 {
1178         return register_filesystem(&fuseblk_fs_type);
1179 }
1180
1181 static inline void unregister_fuseblk(void)
1182 {
1183         unregister_filesystem(&fuseblk_fs_type);
1184 }
1185 #else
1186 static inline int register_fuseblk(void)
1187 {
1188         return 0;
1189 }
1190
1191 static inline void unregister_fuseblk(void)
1192 {
1193 }
1194 #endif
1195
1196 static void fuse_inode_init_once(void *foo)
1197 {
1198         struct inode *inode = foo;
1199
1200         inode_init_once(inode);
1201 }
1202
1203 static int __init fuse_fs_init(void)
1204 {
1205         int err;
1206
1207         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1208                                               sizeof(struct fuse_inode),
1209                                               0, SLAB_HWCACHE_ALIGN,
1210                                               fuse_inode_init_once);
1211         err = -ENOMEM;
1212         if (!fuse_inode_cachep)
1213                 goto out;
1214
1215         err = register_fuseblk();
1216         if (err)
1217                 goto out2;
1218
1219         err = register_filesystem(&fuse_fs_type);
1220         if (err)
1221                 goto out3;
1222
1223         return 0;
1224
1225  out3:
1226         unregister_fuseblk();
1227  out2:
1228         kmem_cache_destroy(fuse_inode_cachep);
1229  out:
1230         return err;
1231 }
1232
1233 static void fuse_fs_cleanup(void)
1234 {
1235         unregister_filesystem(&fuse_fs_type);
1236         unregister_fuseblk();
1237
1238         /*
1239          * Make sure all delayed rcu free inodes are flushed before we
1240          * destroy cache.
1241          */
1242         rcu_barrier();
1243         kmem_cache_destroy(fuse_inode_cachep);
1244 }
1245
1246 static struct kobject *fuse_kobj;
1247 static struct kobject *connections_kobj;
1248
1249 static int fuse_sysfs_init(void)
1250 {
1251         int err;
1252
1253         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1254         if (!fuse_kobj) {
1255                 err = -ENOMEM;
1256                 goto out_err;
1257         }
1258
1259         connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1260         if (!connections_kobj) {
1261                 err = -ENOMEM;
1262                 goto out_fuse_unregister;
1263         }
1264
1265         return 0;
1266
1267  out_fuse_unregister:
1268         kobject_put(fuse_kobj);
1269  out_err:
1270         return err;
1271 }
1272
1273 static void fuse_sysfs_cleanup(void)
1274 {
1275         kobject_put(connections_kobj);
1276         kobject_put(fuse_kobj);
1277 }
1278
1279 static int __init fuse_init(void)
1280 {
1281         int res;
1282
1283         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1284                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1285
1286         INIT_LIST_HEAD(&fuse_conn_list);
1287         res = fuse_fs_init();
1288         if (res)
1289                 goto err;
1290
1291         res = fuse_dev_init();
1292         if (res)
1293                 goto err_fs_cleanup;
1294
1295         res = fuse_sysfs_init();
1296         if (res)
1297                 goto err_dev_cleanup;
1298
1299         res = fuse_ctl_init();
1300         if (res)
1301                 goto err_sysfs_cleanup;
1302
1303         sanitize_global_limit(&max_user_bgreq);
1304         sanitize_global_limit(&max_user_congthresh);
1305
1306         return 0;
1307
1308  err_sysfs_cleanup:
1309         fuse_sysfs_cleanup();
1310  err_dev_cleanup:
1311         fuse_dev_cleanup();
1312  err_fs_cleanup:
1313         fuse_fs_cleanup();
1314  err:
1315         return res;
1316 }
1317
1318 static void __exit fuse_exit(void)
1319 {
1320         printk(KERN_DEBUG "fuse exit\n");
1321
1322         fuse_ctl_cleanup();
1323         fuse_sysfs_cleanup();
1324         fuse_fs_cleanup();
1325         fuse_dev_cleanup();
1326 }
1327
1328 module_init(fuse_init);
1329 module_exit(fuse_exit);