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         if (*flags & MS_MANDLOCK)
 139                 return -EINVAL;
 140
 141         return 0;
 142 }
 143
 144 /*
 145  * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
 146  * so that it will fit.
 147  */
 148 static ino_t fuse_squash_ino(u64 ino64)
 149 {
 150         ino_t ino = (ino_t) ino64;
 151         if (sizeof(ino_t) < sizeof(u64))
 152                 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
 153         return ino;
 154 }
 155
 156 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 157                                    u64 attr_valid)
 158 {
 159         struct fuse_conn *fc = get_fuse_conn(inode);
 160         struct fuse_inode *fi = get_fuse_inode(inode);
 161
 162         fi->attr_version = ++fc->attr_version;
 163         fi->i_time = attr_valid;
 164
 165         inode->i_ino     = fuse_squash_ino(attr->ino);
 166         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 167         set_nlink(inode, attr->nlink);
 168         inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
 169         inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
 170         inode->i_blocks  = attr->blocks;
 171         inode->i_atime.tv_sec   = attr->atime;
 172         inode->i_atime.tv_nsec  = attr->atimensec;
 173         /* mtime from server may be stale due to local buffered write */
 174         if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
 175                 inode->i_mtime.tv_sec   = attr->mtime;
 176                 inode->i_mtime.tv_nsec  = attr->mtimensec;
 177         }
 178         inode->i_ctime.tv_sec   = attr->ctime;
 179         inode->i_ctime.tv_nsec  = attr->ctimensec;
 180
 181         if (attr->blksize != 0)
 182                 inode->i_blkbits = ilog2(attr->blksize);
 183         else
 184                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
 185
 186         /*
 187          * Don't set the sticky bit in i_mode, unless we want the VFS
 188          * to check permissions.  This prevents failures due to the
 189          * check in may_delete().
 190          */
 191         fi->orig_i_mode = inode->i_mode;
 192         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
 193                 inode->i_mode &= ~S_ISVTX;
 194
 195         fi->orig_ino = attr->ino;
 196 }
 197
 198 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 199                             u64 attr_valid, u64 attr_version)
 200 {
 201         struct fuse_conn *fc = get_fuse_conn(inode);
 202         struct fuse_inode *fi = get_fuse_inode(inode);
 203         bool is_wb = fc->writeback_cache;
 204         loff_t oldsize;
 205         struct timespec old_mtime;
 206
 207         spin_lock(&fc->lock);
 208         if ((attr_version != 0 && fi->attr_version > attr_version) ||
 209             test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
 210                 spin_unlock(&fc->lock);
 211                 return;
 212         }
 213
 214         old_mtime = inode->i_mtime;
 215         fuse_change_attributes_common(inode, attr, attr_valid);
 216
 217         oldsize = inode->i_size;
 218         /*
 219          * In case of writeback_cache enabled, the cached writes beyond EOF
 220          * extend local i_size without keeping userspace server in sync. So,
 221          * attr->size coming from server can be stale. We cannot trust it.
 222          */
 223         if (!is_wb || !S_ISREG(inode->i_mode))
 224                 i_size_write(inode, attr->size);
 225         spin_unlock(&fc->lock);
 226
 227         if (!is_wb && S_ISREG(inode->i_mode)) {
 228                 bool inval = false;
 229
 230                 if (oldsize != attr->size) {
 231                         truncate_pagecache(inode, attr->size);
 232                         inval = true;
 233                 } else if (fc->auto_inval_data) {
 234                         struct timespec new_mtime = {
 235                                 .tv_sec = attr->mtime,
 236                                 .tv_nsec = attr->mtimensec,
 237                         };
 238
 239                         /*
 240                          * Auto inval mode also checks and invalidates if mtime
 241                          * has changed.
 242                          */
 243                         if (!timespec_equal(&old_mtime, &new_mtime))
 244                                 inval = true;
 245                 }
 246
 247                 if (inval)
 248                         invalidate_inode_pages2(inode->i_mapping);
 249         }
 250 }
 251
 252 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 253 {
 254         inode->i_mode = attr->mode & S_IFMT;
 255         inode->i_size = attr->size;
 256         inode->i_mtime.tv_sec  = attr->mtime;
 257         inode->i_mtime.tv_nsec = attr->mtimensec;
 258         if (S_ISREG(inode->i_mode)) {
 259                 fuse_init_common(inode);
 260                 fuse_init_file_inode(inode);
 261         } else if (S_ISDIR(inode->i_mode))
 262                 fuse_init_dir(inode);
 263         else if (S_ISLNK(inode->i_mode))
 264                 fuse_init_symlink(inode);
 265         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 266                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 267                 fuse_init_common(inode);
 268                 init_special_inode(inode, inode->i_mode,
 269                                    new_decode_dev(attr->rdev));
 270         } else
 271                 BUG();
 272 }
 273
 274 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 275 {
 276         u64 nodeid = *(u64 *) _nodeidp;
 277         if (get_node_id(inode) == nodeid)
 278                 return 1;
 279         else
 280                 return 0;
 281 }
 282
 283 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 284 {
 285         u64 nodeid = *(u64 *) _nodeidp;
 286         get_fuse_inode(inode)->nodeid = nodeid;
 287         return 0;
 288 }
 289
 290 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 291                         int generation, struct fuse_attr *attr,
 292                         u64 attr_valid, u64 attr_version)
 293 {
 294         struct inode *inode;
 295         struct fuse_inode *fi;
 296         struct fuse_conn *fc = get_fuse_conn_super(sb);
 297
 298  retry:
 299         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 300         if (!inode)
 301                 return NULL;
 302
 303         if ((inode->i_state & I_NEW)) {
 304                 inode->i_flags |= S_NOATIME;
 305                 if (!fc->writeback_cache || !S_ISREG(inode->i_mode))
 306                         inode->i_flags |= S_NOCMTIME;
 307                 inode->i_generation = generation;
 308                 inode->i_data.backing_dev_info = &fc->bdi;
 309                 fuse_init_inode(inode, attr);
 310                 unlock_new_inode(inode);
 311         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 312                 /* Inode has changed type, any I/O on the old should fail */
 313                 make_bad_inode(inode);
 314                 iput(inode);
 315                 goto retry;
 316         }
 317
 318         fi = get_fuse_inode(inode);
 319         spin_lock(&fc->lock);
 320         fi->nlookup++;
 321         spin_unlock(&fc->lock);
 322         fuse_change_attributes(inode, attr, attr_valid, attr_version);
 323
 324         return inode;
 325 }
 326
 327 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 328                              loff_t offset, loff_t len)
 329 {
 330         struct inode *inode;
 331         pgoff_t pg_start;
 332         pgoff_t pg_end;
 333
 334         inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
 335         if (!inode)
 336                 return -ENOENT;
 337
 338         fuse_invalidate_attr(inode);
 339         if (offset >= 0) {
 340                 pg_start = offset >> PAGE_CACHE_SHIFT;
 341                 if (len <= 0)
 342                         pg_end = -1;
 343                 else
 344                         pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
 345                 invalidate_inode_pages2_range(inode->i_mapping,
 346                                               pg_start, pg_end);
 347         }
 348         iput(inode);
 349         return 0;
 350 }
 351
 352 static void fuse_umount_begin(struct super_block *sb)
 353 {
 354         fuse_abort_conn(get_fuse_conn_super(sb));
 355 }
 356
 357 static void fuse_send_destroy(struct fuse_conn *fc)
 358 {
 359         struct fuse_req *req = fc->destroy_req;
 360         if (req && fc->conn_init) {
 361                 fc->destroy_req = NULL;
 362                 req->in.h.opcode = FUSE_DESTROY;
 363                 req->force = 1;
 364                 req->background = 0;
 365                 fuse_request_send(fc, req);
 366                 fuse_put_request(fc, req);
 367         }
 368 }
 369
 370 static void fuse_bdi_destroy(struct fuse_conn *fc)
 371 {
 372         if (fc->bdi_initialized)
 373                 bdi_destroy(&fc->bdi);
 374 }
 375
 376 void fuse_conn_kill(struct fuse_conn *fc)
 377 {
 378         spin_lock(&fc->lock);
 379         fc->connected = 0;
 380         fc->blocked = 0;
 381         fc->initialized = 1;
 382         spin_unlock(&fc->lock);
 383         /* Flush all readers on this fs */
 384         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 385         wake_up_all(&fc->waitq);
 386         wake_up_all(&fc->blocked_waitq);
 387         wake_up_all(&fc->reserved_req_waitq);
 388 }
 389 EXPORT_SYMBOL_GPL(fuse_conn_kill);
 390
 391 static void fuse_put_super(struct super_block *sb)
 392 {
 393         struct fuse_conn *fc = get_fuse_conn_super(sb);
 394
 395         fuse_send_destroy(fc);
 396
 397         fuse_conn_kill(fc);
 398         mutex_lock(&fuse_mutex);
 399         list_del(&fc->entry);
 400         fuse_ctl_remove_conn(fc);
 401         mutex_unlock(&fuse_mutex);
 402         fuse_bdi_destroy(fc);
 403
 404         fuse_conn_put(fc);
 405 }
 406
 407 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 408 {
 409         stbuf->f_type    = FUSE_SUPER_MAGIC;
 410         stbuf->f_bsize   = attr->bsize;
 411         stbuf->f_frsize  = attr->frsize;
 412         stbuf->f_blocks  = attr->blocks;
 413         stbuf->f_bfree   = attr->bfree;
 414         stbuf->f_bavail  = attr->bavail;
 415         stbuf->f_files   = attr->files;
 416         stbuf->f_ffree   = attr->ffree;
 417         stbuf->f_namelen = attr->namelen;
 418         /* fsid is left zero */
 419 }
 420
 421 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 422 {
 423         struct super_block *sb = dentry->d_sb;
 424         struct fuse_conn *fc = get_fuse_conn_super(sb);
 425         struct fuse_req *req;
 426         struct fuse_statfs_out outarg;
 427         int err;
 428
 429         if (!fuse_allow_current_process(fc)) {
 430                 buf->f_type = FUSE_SUPER_MAGIC;
 431                 return 0;
 432         }
 433
 434         req = fuse_get_req_nopages(fc);
 435         if (IS_ERR(req))
 436                 return PTR_ERR(req);
 437
 438         memset(&outarg, 0, sizeof(outarg));
 439         req->in.numargs = 0;
 440         req->in.h.opcode = FUSE_STATFS;
 441         req->in.h.nodeid = get_node_id(dentry->d_inode);
 442         req->out.numargs = 1;
 443         req->out.args[0].size =
 444                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 445         req->out.args[0].value = &outarg;
 446         fuse_request_send(fc, req);
 447         err = req->out.h.error;
 448         if (!err)
 449                 convert_fuse_statfs(buf, &outarg.st);
 450         fuse_put_request(fc, req);
 451         return err;
 452 }
 453
 454 enum {
 455         OPT_FD,
 456         OPT_ROOTMODE,
 457         OPT_USER_ID,
 458         OPT_GROUP_ID,
 459         OPT_DEFAULT_PERMISSIONS,
 460         OPT_ALLOW_OTHER,
 461         OPT_MAX_READ,
 462         OPT_BLKSIZE,
 463         OPT_ERR
 464 };
 465
 466 static const match_table_t tokens = {
 467         {OPT_FD,                        "fd=%u"},
 468         {OPT_ROOTMODE,                  "rootmode=%o"},
 469         {OPT_USER_ID,                   "user_id=%u"},
 470         {OPT_GROUP_ID,                  "group_id=%u"},
 471         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 472         {OPT_ALLOW_OTHER,               "allow_other"},
 473         {OPT_MAX_READ,                  "max_read=%u"},
 474         {OPT_BLKSIZE,                   "blksize=%u"},
 475         {OPT_ERR,                       NULL}
 476 };
 477
 478 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 479 {
 480         char *p;
 481         memset(d, 0, sizeof(struct fuse_mount_data));
 482         d->max_read = ~0;
 483         d->blksize = FUSE_DEFAULT_BLKSIZE;
 484
 485         while ((p = strsep(&opt, ",")) != NULL) {
 486                 int token;
 487                 int value;
 488                 substring_t args[MAX_OPT_ARGS];
 489                 if (!*p)
 490                         continue;
 491
 492                 token = match_token(p, tokens, args);
 493                 switch (token) {
 494                 case OPT_FD:
 495                         if (match_int(&args[0], &value))
 496                                 return 0;
 497                         d->fd = value;
 498                         d->fd_present = 1;
 499                         break;
 500
 501                 case OPT_ROOTMODE:
 502                         if (match_octal(&args[0], &value))
 503                                 return 0;
 504                         if (!fuse_valid_type(value))
 505                                 return 0;
 506                         d->rootmode = value;
 507                         d->rootmode_present = 1;
 508                         break;
 509
 510                 case OPT_USER_ID:
 511                         if (match_int(&args[0], &value))
 512                                 return 0;
 513                         d->user_id = make_kuid(current_user_ns(), value);
 514                         if (!uid_valid(d->user_id))
 515                                 return 0;
 516                         d->user_id_present = 1;
 517                         break;
 518
 519                 case OPT_GROUP_ID:
 520                         if (match_int(&args[0], &value))
 521                                 return 0;
 522                         d->group_id = make_kgid(current_user_ns(), value);
 523                         if (!gid_valid(d->group_id))
 524                                 return 0;
 525                         d->group_id_present = 1;
 526                         break;
 527
 528                 case OPT_DEFAULT_PERMISSIONS:
 529                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 530                         break;
 531
 532                 case OPT_ALLOW_OTHER:
 533                         d->flags |= FUSE_ALLOW_OTHER;
 534                         break;
 535
 536                 case OPT_MAX_READ:
 537                         if (match_int(&args[0], &value))
 538                                 return 0;
 539                         d->max_read = value;
 540                         break;
 541
 542                 case OPT_BLKSIZE:
 543                         if (!is_bdev || match_int(&args[0], &value))
 544                                 return 0;
 545                         d->blksize = value;
 546                         break;
 547
 548                 default:
 549                         return 0;
 550                 }
 551         }
 552
 553         if (!d->fd_present || !d->rootmode_present ||
 554             !d->user_id_present || !d->group_id_present)
 555                 return 0;
 556
 557         return 1;
 558 }
 559
 560 static int fuse_show_options(struct seq_file *m, struct dentry *root)
 561 {
 562         struct super_block *sb = root->d_sb;
 563         struct fuse_conn *fc = get_fuse_conn_super(sb);
 564
 565         seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
 566         seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
 567         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 568                 seq_puts(m, ",default_permissions");
 569         if (fc->flags & FUSE_ALLOW_OTHER)
 570                 seq_puts(m, ",allow_other");
 571         if (fc->max_read != ~0)
 572                 seq_printf(m, ",max_read=%u", fc->max_read);
 573         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 574                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
 575         return 0;
 576 }
 577
 578 void fuse_conn_init(struct fuse_conn *fc)
 579 {
 580         memset(fc, 0, sizeof(*fc));
 581         spin_lock_init(&fc->lock);
 582         init_rwsem(&fc->killsb);
 583         atomic_set(&fc->count, 1);
 584         init_waitqueue_head(&fc->waitq);
 585         init_waitqueue_head(&fc->blocked_waitq);
 586         init_waitqueue_head(&fc->reserved_req_waitq);
 587         INIT_LIST_HEAD(&fc->pending);
 588         INIT_LIST_HEAD(&fc->processing);
 589         INIT_LIST_HEAD(&fc->io);
 590         INIT_LIST_HEAD(&fc->interrupts);
 591         INIT_LIST_HEAD(&fc->bg_queue);
 592         INIT_LIST_HEAD(&fc->entry);
 593         fc->forget_list_tail = &fc->forget_list_head;
 594         atomic_set(&fc->num_waiting, 0);
 595         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
 596         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
 597         fc->khctr = 0;
 598         fc->polled_files = RB_ROOT;
 599         fc->reqctr = 0;
 600         fc->blocked = 0;
 601         fc->initialized = 0;
 602         fc->attr_version = 1;
 603         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 604 }
 605 EXPORT_SYMBOL_GPL(fuse_conn_init);
 606
 607 void fuse_conn_put(struct fuse_conn *fc)
 608 {
 609         if (atomic_dec_and_test(&fc->count)) {
 610                 if (fc->destroy_req)
 611                         fuse_request_free(fc->destroy_req);
 612                 fc->release(fc);
 613         }
 614 }
 615 EXPORT_SYMBOL_GPL(fuse_conn_put);
 616
 617 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 618 {
 619         atomic_inc(&fc->count);
 620         return fc;
 621 }
 622 EXPORT_SYMBOL_GPL(fuse_conn_get);
 623
 624 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 625 {
 626         struct fuse_attr attr;
 627         memset(&attr, 0, sizeof(attr));
 628
 629         attr.mode = mode;
 630         attr.ino = FUSE_ROOT_ID;
 631         attr.nlink = 1;
 632         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 633 }
 634
 635 struct fuse_inode_handle {
 636         u64 nodeid;
 637         u32 generation;
 638 };
 639
 640 static struct dentry *fuse_get_dentry(struct super_block *sb,
 641                                       struct fuse_inode_handle *handle)
 642 {
 643         struct fuse_conn *fc = get_fuse_conn_super(sb);
 644         struct inode *inode;
 645         struct dentry *entry;
 646         int err = -ESTALE;
 647
 648         if (handle->nodeid == 0)
 649                 goto out_err;
 650
 651         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
 652         if (!inode) {
 653                 struct fuse_entry_out outarg;
 654                 struct qstr name;
 655
 656                 if (!fc->export_support)
 657                         goto out_err;
 658
 659                 name.len = 1;
 660                 name.name = ".";
 661                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
 662                                        &inode);
 663                 if (err && err != -ENOENT)
 664                         goto out_err;
 665                 if (err || !inode) {
 666                         err = -ESTALE;
 667                         goto out_err;
 668                 }
 669                 err = -EIO;
 670                 if (get_node_id(inode) != handle->nodeid)
 671                         goto out_iput;
 672         }
 673         err = -ESTALE;
 674         if (inode->i_generation != handle->generation)
 675                 goto out_iput;
 676
 677         entry = d_obtain_alias(inode);
 678         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
 679                 fuse_invalidate_entry_cache(entry);
 680
 681         return entry;
 682
 683  out_iput:
 684         iput(inode);
 685  out_err:
 686         return ERR_PTR(err);
 687 }
 688
 689 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 690                            struct inode *parent)
 691 {
 692         int len = parent ? 6 : 3;
 693         u64 nodeid;
 694         u32 generation;
 695
 696         if (*max_len < len) {
 697                 *max_len = len;
 698                 return  FILEID_INVALID;
 699         }
 700
 701         nodeid = get_fuse_inode(inode)->nodeid;
 702         generation = inode->i_generation;
 703
 704         fh[0] = (u32)(nodeid >> 32);
 705         fh[1] = (u32)(nodeid & 0xffffffff);
 706         fh[2] = generation;
 707
 708         if (parent) {
 709                 nodeid = get_fuse_inode(parent)->nodeid;
 710                 generation = parent->i_generation;
 711
 712                 fh[3] = (u32)(nodeid >> 32);
 713                 fh[4] = (u32)(nodeid & 0xffffffff);
 714                 fh[5] = generation;
 715         }
 716
 717         *max_len = len;
 718         return parent ? 0x82 : 0x81;
 719 }
 720
 721 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
 722                 struct fid *fid, int fh_len, int fh_type)
 723 {
 724         struct fuse_inode_handle handle;
 725
 726         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
 727                 return NULL;
 728
 729         handle.nodeid = (u64) fid->raw[0] << 32;
 730         handle.nodeid |= (u64) fid->raw[1];
 731         handle.generation = fid->raw[2];
 732         return fuse_get_dentry(sb, &handle);
 733 }
 734
 735 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
 736                 struct fid *fid, int fh_len, int fh_type)
 737 {
 738         struct fuse_inode_handle parent;
 739
 740         if (fh_type != 0x82 || fh_len < 6)
 741                 return NULL;
 742
 743         parent.nodeid = (u64) fid->raw[3] << 32;
 744         parent.nodeid |= (u64) fid->raw[4];
 745         parent.generation = fid->raw[5];
 746         return fuse_get_dentry(sb, &parent);
 747 }
 748
 749 static struct dentry *fuse_get_parent(struct dentry *child)
 750 {
 751         struct inode *child_inode = child->d_inode;
 752         struct fuse_conn *fc = get_fuse_conn(child_inode);
 753         struct inode *inode;
 754         struct dentry *parent;
 755         struct fuse_entry_out outarg;
 756         struct qstr name;
 757         int err;
 758
 759         if (!fc->export_support)
 760                 return ERR_PTR(-ESTALE);
 761
 762         name.len = 2;
 763         name.name = "..";
 764         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
 765                                &name, &outarg, &inode);
 766         if (err) {
 767                 if (err == -ENOENT)
 768                         return ERR_PTR(-ESTALE);
 769                 return ERR_PTR(err);
 770         }
 771
 772         parent = d_obtain_alias(inode);
 773         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
 774                 fuse_invalidate_entry_cache(parent);
 775
 776         return parent;
 777 }
 778
 779 static const struct export_operations fuse_export_operations = {
 780         .fh_to_dentry   = fuse_fh_to_dentry,
 781         .fh_to_parent   = fuse_fh_to_parent,
 782         .encode_fh      = fuse_encode_fh,
 783         .get_parent     = fuse_get_parent,
 784 };
 785
 786 static const struct super_operations fuse_super_operations = {
 787         .alloc_inode    = fuse_alloc_inode,
 788         .destroy_inode  = fuse_destroy_inode,
 789         .evict_inode    = fuse_evict_inode,
 790         .drop_inode     = generic_delete_inode,
 791         .remount_fs     = fuse_remount_fs,
 792         .put_super      = fuse_put_super,
 793         .umount_begin   = fuse_umount_begin,
 794         .statfs         = fuse_statfs,
 795         .show_options   = fuse_show_options,
 796 };
 797
 798 static void sanitize_global_limit(unsigned *limit)
 799 {
 800         if (*limit == 0)
 801                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
 802                          sizeof(struct fuse_req);
 803
 804         if (*limit >= 1 << 16)
 805                 *limit = (1 << 16) - 1;
 806 }
 807
 808 static int set_global_limit(const char *val, struct kernel_param *kp)
 809 {
 810         int rv;
 811
 812         rv = param_set_uint(val, kp);
 813         if (rv)
 814                 return rv;
 815
 816         sanitize_global_limit((unsigned *)kp->arg);
 817
 818         return 0;
 819 }
 820
 821 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
 822 {
 823         int cap_sys_admin = capable(CAP_SYS_ADMIN);
 824
 825         if (arg->minor < 13)
 826                 return;
 827
 828         sanitize_global_limit(&max_user_bgreq);
 829         sanitize_global_limit(&max_user_congthresh);
 830
 831         if (arg->max_background) {
 832                 fc->max_background = arg->max_background;
 833
 834                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
 835                         fc->max_background = max_user_bgreq;
 836         }
 837         if (arg->congestion_threshold) {
 838                 fc->congestion_threshold = arg->congestion_threshold;
 839
 840                 if (!cap_sys_admin &&
 841                     fc->congestion_threshold > max_user_congthresh)
 842                         fc->congestion_threshold = max_user_congthresh;
 843         }
 844 }
 845
 846 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 847 {
 848         struct fuse_init_out *arg = &req->misc.init_out;
 849
 850         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 851                 fc->conn_error = 1;
 852         else {
 853                 unsigned long ra_pages;
 854
 855                 process_init_limits(fc, arg);
 856
 857                 if (arg->minor >= 6) {
 858                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 859                         if (arg->flags & FUSE_ASYNC_READ)
 860                                 fc->async_read = 1;
 861                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 862                                 fc->no_lock = 1;
 863                         if (arg->minor >= 17) {
 864                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
 865                                         fc->no_flock = 1;
 866                         } else {
 867                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
 868                                         fc->no_flock = 1;
 869                         }
 870                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 871                                 fc->atomic_o_trunc = 1;
 872                         if (arg->minor >= 9) {
 873                                 /* LOOKUP has dependency on proto version */
 874                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
 875                                         fc->export_support = 1;
 876                         }
 877                         if (arg->flags & FUSE_BIG_WRITES)
 878                                 fc->big_writes = 1;
 879                         if (arg->flags & FUSE_DONT_MASK)
 880                                 fc->dont_mask = 1;
 881                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
 882                                 fc->auto_inval_data = 1;
 883                         if (arg->flags & FUSE_DO_READDIRPLUS) {
 884                                 fc->do_readdirplus = 1;
 885                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
 886                                         fc->readdirplus_auto = 1;
 887                         }
 888                         if (arg->flags & FUSE_ASYNC_DIO)
 889                                 fc->async_dio = 1;
 890                         if (arg->flags & FUSE_WRITEBACK_CACHE)
 891                                 fc->writeback_cache = 1;
 892                 } else {
 893                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 894                         fc->no_lock = 1;
 895                         fc->no_flock = 1;
 896                 }
 897
 898                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 899                 fc->minor = arg->minor;
 900                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 901                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
 902                 fc->conn_init = 1;
 903         }
 904         fc->initialized = 1;
 905         wake_up_all(&fc->blocked_waitq);
 906 }
 907
 908 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 909 {
 910         struct fuse_init_in *arg = &req->misc.init_in;
 911
 912         arg->major = FUSE_KERNEL_VERSION;
 913         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 914         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 915         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
 916                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
 917                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
 918                 FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
 919                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
 920                 FUSE_WRITEBACK_CACHE;
 921         req->in.h.opcode = FUSE_INIT;
 922         req->in.numargs = 1;
 923         req->in.args[0].size = sizeof(*arg);
 924         req->in.args[0].value = arg;
 925         req->out.numargs = 1;
 926         /* Variable length argument used for backward compatibility
 927            with interface version < 7.5.  Rest of init_out is zeroed
 928            by do_get_request(), so a short reply is not a problem */
 929         req->out.argvar = 1;
 930         req->out.args[0].size = sizeof(struct fuse_init_out);
 931         req->out.args[0].value = &req->misc.init_out;
 932         req->end = process_init_reply;
 933         fuse_request_send_background(fc, req);
 934 }
 935
 936 static void fuse_free_conn(struct fuse_conn *fc)
 937 {
 938         kfree_rcu(fc, rcu);
 939 }
 940
 941 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 942 {
 943         int err;
 944
 945         fc->bdi.name = "fuse";
 946         fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 947         /* fuse does it's own writeback accounting */
 948         fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 949
 950         err = bdi_init(&fc->bdi);
 951         if (err)
 952                 return err;
 953
 954         fc->bdi_initialized = 1;
 955
 956         if (sb->s_bdev) {
 957                 err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
 958                                     MAJOR(fc->dev), MINOR(fc->dev));
 959         } else {
 960                 err = bdi_register_dev(&fc->bdi, fc->dev);
 961         }
 962
 963         if (err)
 964                 return err;
 965
 966         /*
 967          * For a single fuse filesystem use max 1% of dirty +
 968          * writeback threshold.
 969          *
 970          * This gives about 1M of write buffer for memory maps on a
 971          * machine with 1G and 10% dirty_ratio, which should be more
 972          * than enough.
 973          *
 974          * Privileged users can raise it by writing to
 975          *
 976          *    /sys/class/bdi/<bdi>/max_ratio
 977          */
 978         bdi_set_max_ratio(&fc->bdi, 1);
 979
 980         return 0;
 981 }
 982
 983 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 984 {
 985         struct fuse_conn *fc;
 986         struct inode *root;
 987         struct fuse_mount_data d;
 988         struct file *file;
 989         struct dentry *root_dentry;
 990         struct fuse_req *init_req;
 991         int err;
 992         int is_bdev = sb->s_bdev != NULL;
 993
 994         err = -EINVAL;
 995         if (sb->s_flags & MS_MANDLOCK)
 996                 goto err;
 997
 998         sb->s_flags &= ~MS_NOSEC;
 999
1000         if (!parse_fuse_opt((char *) data, &d, is_bdev))
1001                 goto err;
1002
1003         if (is_bdev) {
1004 #ifdef CONFIG_BLOCK
1005                 err = -EINVAL;
1006                 if (!sb_set_blocksize(sb, d.blksize))
1007                         goto err;
1008 #endif
1009         } else {
1010                 sb->s_blocksize = PAGE_CACHE_SIZE;
1011                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1012         }
1013         sb->s_magic = FUSE_SUPER_MAGIC;
1014         sb->s_op = &fuse_super_operations;
1015         sb->s_maxbytes = MAX_LFS_FILESIZE;
1016         sb->s_time_gran = 1;
1017         sb->s_export_op = &fuse_export_operations;
1018
1019         file = fget(d.fd);
1020         err = -EINVAL;
1021         if (!file)
1022                 goto err;
1023
1024         if ((file->f_op != &fuse_dev_operations) ||
1025             (file->f_cred->user_ns != &init_user_ns))
1026                 goto err_fput;
1027
1028         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1029         err = -ENOMEM;
1030         if (!fc)
1031                 goto err_fput;
1032
1033         fuse_conn_init(fc);
1034
1035         fc->dev = sb->s_dev;
1036         fc->sb = sb;
1037         err = fuse_bdi_init(fc, sb);
1038         if (err)
1039                 goto err_put_conn;
1040
1041         sb->s_bdi = &fc->bdi;
1042
1043         /* Handle umasking inside the fuse code */
1044         if (sb->s_flags & MS_POSIXACL)
1045                 fc->dont_mask = 1;
1046         sb->s_flags |= MS_POSIXACL;
1047
1048         fc->release = fuse_free_conn;
1049         fc->flags = d.flags;
1050         fc->user_id = d.user_id;
1051         fc->group_id = d.group_id;
1052         fc->max_read = max_t(unsigned, 4096, d.max_read);
1053
1054         /* Used by get_root_inode() */
1055         sb->s_fs_info = fc;
1056
1057         err = -ENOMEM;
1058         root = fuse_get_root_inode(sb, d.rootmode);
1059         root_dentry = d_make_root(root);
1060         if (!root_dentry)
1061                 goto err_put_conn;
1062         /* only now - we want root dentry with NULL ->d_op */
1063         sb->s_d_op = &fuse_dentry_operations;
1064
1065         init_req = fuse_request_alloc(0);
1066         if (!init_req)
1067                 goto err_put_root;
1068         init_req->background = 1;
1069
1070         if (is_bdev) {
1071                 fc->destroy_req = fuse_request_alloc(0);
1072                 if (!fc->destroy_req)
1073                         goto err_free_init_req;
1074         }
1075
1076         mutex_lock(&fuse_mutex);
1077         err = -EINVAL;
1078         if (file->private_data)
1079                 goto err_unlock;
1080
1081         err = fuse_ctl_add_conn(fc);
1082         if (err)
1083                 goto err_unlock;
1084
1085         list_add_tail(&fc->entry, &fuse_conn_list);
1086         sb->s_root = root_dentry;
1087         fc->connected = 1;
1088         file->private_data = fuse_conn_get(fc);
1089         mutex_unlock(&fuse_mutex);
1090         /*
1091          * atomic_dec_and_test() in fput() provides the necessary
1092          * memory barrier for file->private_data to be visible on all
1093          * CPUs after this
1094          */
1095         fput(file);
1096
1097         fuse_send_init(fc, init_req);
1098
1099         return 0;
1100
1101  err_unlock:
1102         mutex_unlock(&fuse_mutex);
1103  err_free_init_req:
1104         fuse_request_free(init_req);
1105  err_put_root:
1106         dput(root_dentry);
1107  err_put_conn:
1108         fuse_bdi_destroy(fc);
1109         fuse_conn_put(fc);
1110  err_fput:
1111         fput(file);
1112  err:
1113         return err;
1114 }
1115
1116 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1117                        int flags, const char *dev_name,
1118                        void *raw_data)
1119 {
1120         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1121 }
1122
1123 static void fuse_kill_sb_anon(struct super_block *sb)
1124 {
1125         struct fuse_conn *fc = get_fuse_conn_super(sb);
1126
1127         if (fc) {
1128                 down_write(&fc->killsb);
1129                 fc->sb = NULL;
1130                 up_write(&fc->killsb);
1131         }
1132
1133         kill_anon_super(sb);
1134 }
1135
1136 static struct file_system_type fuse_fs_type = {
1137         .owner          = THIS_MODULE,
1138         .name           = "fuse",
1139         .fs_flags       = FS_HAS_SUBTYPE,
1140         .mount          = fuse_mount,
1141         .kill_sb        = fuse_kill_sb_anon,
1142 };
1143 MODULE_ALIAS_FS("fuse");
1144
1145 #ifdef CONFIG_BLOCK
1146 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1147                            int flags, const char *dev_name,
1148                            void *raw_data)
1149 {
1150         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1151 }
1152
1153 static void fuse_kill_sb_blk(struct super_block *sb)
1154 {
1155         struct fuse_conn *fc = get_fuse_conn_super(sb);
1156
1157         if (fc) {
1158                 down_write(&fc->killsb);
1159                 fc->sb = NULL;
1160                 up_write(&fc->killsb);
1161         }
1162
1163         kill_block_super(sb);
1164 }
1165
1166 static struct file_system_type fuseblk_fs_type = {
1167         .owner          = THIS_MODULE,
1168         .name           = "fuseblk",
1169         .mount          = fuse_mount_blk,
1170         .kill_sb        = fuse_kill_sb_blk,
1171         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1172 };
1173 MODULE_ALIAS_FS("fuseblk");
1174
1175 static inline int register_fuseblk(void)
1176 {
1177         return register_filesystem(&fuseblk_fs_type);
1178 }
1179
1180 static inline void unregister_fuseblk(void)
1181 {
1182         unregister_filesystem(&fuseblk_fs_type);
1183 }
1184 #else
1185 static inline int register_fuseblk(void)
1186 {
1187         return 0;
1188 }
1189
1190 static inline void unregister_fuseblk(void)
1191 {
1192 }
1193 #endif
1194
1195 static void fuse_inode_init_once(void *foo)
1196 {
1197         struct inode *inode = foo;
1198
1199         inode_init_once(inode);
1200 }
1201
1202 static int __init fuse_fs_init(void)
1203 {
1204         int err;
1205
1206         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1207                                               sizeof(struct fuse_inode),
1208                                               0, SLAB_HWCACHE_ALIGN,
1209                                               fuse_inode_init_once);
1210         err = -ENOMEM;
1211         if (!fuse_inode_cachep)
1212                 goto out;
1213
1214         err = register_fuseblk();
1215         if (err)
1216                 goto out2;
1217
1218         err = register_filesystem(&fuse_fs_type);
1219         if (err)
1220                 goto out3;
1221
1222         return 0;
1223
1224  out3:
1225         unregister_fuseblk();
1226  out2:
1227         kmem_cache_destroy(fuse_inode_cachep);
1228  out:
1229         return err;
1230 }
1231
1232 static void fuse_fs_cleanup(void)
1233 {
1234         unregister_filesystem(&fuse_fs_type);
1235         unregister_fuseblk();
1236
1237         /*
1238          * Make sure all delayed rcu free inodes are flushed before we
1239          * destroy cache.
1240          */
1241         rcu_barrier();
1242         kmem_cache_destroy(fuse_inode_cachep);
1243 }
1244
1245 static struct kobject *fuse_kobj;
1246 static struct kobject *connections_kobj;
1247
1248 static int fuse_sysfs_init(void)
1249 {
1250         int err;
1251
1252         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1253         if (!fuse_kobj) {
1254                 err = -ENOMEM;
1255                 goto out_err;
1256         }
1257
1258         connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1259         if (!connections_kobj) {
1260                 err = -ENOMEM;
1261                 goto out_fuse_unregister;
1262         }
1263
1264         return 0;
1265
1266  out_fuse_unregister:
1267         kobject_put(fuse_kobj);
1268  out_err:
1269         return err;
1270 }
1271
1272 static void fuse_sysfs_cleanup(void)
1273 {
1274         kobject_put(connections_kobj);
1275         kobject_put(fuse_kobj);
1276 }
1277
1278 static int __init fuse_init(void)
1279 {
1280         int res;
1281
1282         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1283                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1284
1285         INIT_LIST_HEAD(&fuse_conn_list);
1286         res = fuse_fs_init();
1287         if (res)
1288                 goto err;
1289
1290         res = fuse_dev_init();
1291         if (res)
1292                 goto err_fs_cleanup;
1293
1294         res = fuse_sysfs_init();
1295         if (res)
1296                 goto err_dev_cleanup;
1297
1298         res = fuse_ctl_init();
1299         if (res)
1300                 goto err_sysfs_cleanup;
1301
1302         sanitize_global_limit(&max_user_bgreq);
1303         sanitize_global_limit(&max_user_congthresh);
1304
1305         return 0;
1306
1307  err_sysfs_cleanup:
1308         fuse_sysfs_cleanup();
1309  err_dev_cleanup:
1310         fuse_dev_cleanup();
1311  err_fs_cleanup:
1312         fuse_fs_cleanup();
1313  err:
1314         return res;
1315 }
1316
1317 static void __exit fuse_exit(void)
1318 {
1319         printk(KERN_DEBUG "fuse exit\n");
1320
1321         fuse_ctl_cleanup();
1322         fuse_sysfs_cleanup();
1323         fuse_fs_cleanup();
1324         fuse_dev_cleanup();
1325 }
1326
1327 module_init(fuse_init);
1328 module_exit(fuse_exit);