fs/fuse/inode.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2008  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU GPL.
   6   See the file COPYING.
   7 */
   8
   9 #include "fuse_i.h"
  10
  11 #include <linux/pagemap.h>
  12 #include <linux/slab.h>
  13 #include <linux/file.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/moduleparam.h>
  18 #include <linux/parser.h>
  19 #include <linux/statfs.h>
  20 #include <linux/random.h>
  21 #include <linux/sched.h>
  22 #include <linux/exportfs.h>
  23
  24 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
  25 MODULE_DESCRIPTION("Filesystem in Userspace");
  26 MODULE_LICENSE("GPL");
  27
  28 static struct kmem_cache *fuse_inode_cachep;
  29 struct list_head fuse_conn_list;
  30 DEFINE_MUTEX(fuse_mutex);
  31
  32 static int set_global_limit(const char *val, struct kernel_param *kp);
  33
  34 unsigned max_user_bgreq;
  35 module_param_call(max_user_bgreq, set_global_limit, param_get_uint,
  36                   &max_user_bgreq, 0644);
  37 __MODULE_PARM_TYPE(max_user_bgreq, "uint");
  38 MODULE_PARM_DESC(max_user_bgreq,
  39  "Global limit for the maximum number of backgrounded requests an "
  40  "unprivileged user can set");
  41
  42 unsigned max_user_congthresh;
  43 module_param_call(max_user_congthresh, set_global_limit, param_get_uint,
  44                   &max_user_congthresh, 0644);
  45 __MODULE_PARM_TYPE(max_user_congthresh, "uint");
  46 MODULE_PARM_DESC(max_user_congthresh,
  47  "Global limit for the maximum congestion threshold an "
  48  "unprivileged user can set");
  49
  50 #define FUSE_SUPER_MAGIC 0x65735546
  51
  52 #define FUSE_DEFAULT_BLKSIZE 512
  53
  54 /** Maximum number of outstanding background requests */
  55 #define FUSE_DEFAULT_MAX_BACKGROUND 12
  56
  57 /** Congestion starts at 75% of maximum */
  58 #define FUSE_DEFAULT_CONGESTION_THRESHOLD (FUSE_DEFAULT_MAX_BACKGROUND * 3 / 4)
  59
  60 struct fuse_mount_data {
  61         int fd;
  62         unsigned rootmode;
  63         kuid_t user_id;
  64         kgid_t group_id;
  65         unsigned fd_present:1;
  66         unsigned rootmode_present:1;
  67         unsigned user_id_present:1;
  68         unsigned group_id_present:1;
  69         unsigned flags;
  70         unsigned max_read;
  71         unsigned blksize;
  72 };
  73
  74 struct fuse_forget_link *fuse_alloc_forget(void)
  75 {
  76         return kzalloc(sizeof(struct fuse_forget_link), GFP_KERNEL);
  77 }
  78
  79 static struct inode *fuse_alloc_inode(struct super_block *sb)
  80 {
  81         struct inode *inode;
  82         struct fuse_inode *fi;
  83
  84         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
  85         if (!inode)
  86                 return NULL;
  87
  88         fi = get_fuse_inode(inode);
  89         fi->i_time = 0;
  90         fi->nodeid = 0;
  91         fi->nlookup = 0;
  92         fi->attr_version = 0;
  93         fi->writectr = 0;
  94         fi->orig_ino = 0;
  95         fi->state = 0;
  96         INIT_LIST_HEAD(&fi->write_files);
  97         INIT_LIST_HEAD(&fi->queued_writes);
  98         INIT_LIST_HEAD(&fi->writepages);
  99         init_waitqueue_head(&fi->page_waitq);
 100         fi->forget = fuse_alloc_forget();
 101         if (!fi->forget) {
 102                 kmem_cache_free(fuse_inode_cachep, inode);
 103                 return NULL;
 104         }
 105
 106         return inode;
 107 }
 108
 109 static void fuse_i_callback(struct rcu_head *head)
 110 {
 111         struct inode *inode = container_of(head, struct inode, i_rcu);
 112         kmem_cache_free(fuse_inode_cachep, inode);
 113 }
 114
 115 static void fuse_destroy_inode(struct inode *inode)
 116 {
 117         struct fuse_inode *fi = get_fuse_inode(inode);
 118         BUG_ON(!list_empty(&fi->write_files));
 119         BUG_ON(!list_empty(&fi->queued_writes));
 120         kfree(fi->forget);
 121         call_rcu(&inode->i_rcu, fuse_i_callback);
 122 }
 123
 124 static void fuse_evict_inode(struct inode *inode)
 125 {
 126         truncate_inode_pages_final(&inode->i_data);
 127         clear_inode(inode);
 128         if (inode->i_sb->s_flags & MS_ACTIVE) {
 129                 struct fuse_conn *fc = get_fuse_conn(inode);
 130                 struct fuse_inode *fi = get_fuse_inode(inode);
 131                 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
 132                 fi->forget = NULL;
 133         }
 134 }
 135
 136 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 137 {
 138         sync_filesystem(sb);
 139         if (*flags & MS_MANDLOCK)
 140                 return -EINVAL;
 141
 142         return 0;
 143 }
 144
 145 /*
 146  * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
 147  * so that it will fit.
 148  */
 149 static ino_t fuse_squash_ino(u64 ino64)
 150 {
 151         ino_t ino = (ino_t) ino64;
 152         if (sizeof(ino_t) < sizeof(u64))
 153                 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
 154         return ino;
 155 }
 156
 157 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 158                                    u64 attr_valid)
 159 {
 160         struct fuse_conn *fc = get_fuse_conn(inode);
 161         struct fuse_inode *fi = get_fuse_inode(inode);
 162
 163         fi->attr_version = ++fc->attr_version;
 164         fi->i_time = attr_valid;
 165
 166         inode->i_ino     = fuse_squash_ino(attr->ino);
 167         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 168         set_nlink(inode, attr->nlink);
 169         inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
 170         inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
 171         inode->i_blocks  = attr->blocks;
 172         inode->i_atime.tv_sec   = attr->atime;
 173         inode->i_atime.tv_nsec  = attr->atimensec;
 174         /* mtime from server may be stale due to local buffered write */
 175         if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
 176                 inode->i_mtime.tv_sec   = attr->mtime;
 177                 inode->i_mtime.tv_nsec  = attr->mtimensec;
 178                 inode->i_ctime.tv_sec   = attr->ctime;
 179                 inode->i_ctime.tv_nsec  = attr->ctimensec;
 180         }
 181
 182         if (attr->blksize != 0)
 183                 inode->i_blkbits = ilog2(attr->blksize);
 184         else
 185                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
 186
 187         /*
 188          * Don't set the sticky bit in i_mode, unless we want the VFS
 189          * to check permissions.  This prevents failures due to the
 190          * check in may_delete().
 191          */
 192         fi->orig_i_mode = inode->i_mode;
 193         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
 194                 inode->i_mode &= ~S_ISVTX;
 195
 196         fi->orig_ino = attr->ino;
 197 }
 198
 199 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 200                             u64 attr_valid, u64 attr_version)
 201 {
 202         struct fuse_conn *fc = get_fuse_conn(inode);
 203         struct fuse_inode *fi = get_fuse_inode(inode);
 204         bool is_wb = fc->writeback_cache;
 205         loff_t oldsize;
 206         struct timespec old_mtime;
 207
 208         spin_lock(&fc->lock);
 209         if ((attr_version != 0 && fi->attr_version > attr_version) ||
 210             test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
 211                 spin_unlock(&fc->lock);
 212                 return;
 213         }
 214
 215         old_mtime = inode->i_mtime;
 216         fuse_change_attributes_common(inode, attr, attr_valid);
 217
 218         oldsize = inode->i_size;
 219         /*
 220          * In case of writeback_cache enabled, the cached writes beyond EOF
 221          * extend local i_size without keeping userspace server in sync. So,
 222          * attr->size coming from server can be stale. We cannot trust it.
 223          */
 224         if (!is_wb || !S_ISREG(inode->i_mode))
 225                 i_size_write(inode, attr->size);
 226         spin_unlock(&fc->lock);
 227
 228         if (!is_wb && S_ISREG(inode->i_mode)) {
 229                 bool inval = false;
 230
 231                 if (oldsize != attr->size) {
 232                         truncate_pagecache(inode, attr->size);
 233                         inval = true;
 234                 } else if (fc->auto_inval_data) {
 235                         struct timespec new_mtime = {
 236                                 .tv_sec = attr->mtime,
 237                                 .tv_nsec = attr->mtimensec,
 238                         };
 239
 240                         /*
 241                          * Auto inval mode also checks and invalidates if mtime
 242                          * has changed.
 243                          */
 244                         if (!timespec_equal(&old_mtime, &new_mtime))
 245                                 inval = true;
 246                 }
 247
 248                 if (inval)
 249                         invalidate_inode_pages2(inode->i_mapping);
 250         }
 251 }
 252
 253 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 254 {
 255         inode->i_mode = attr->mode & S_IFMT;
 256         inode->i_size = attr->size;
 257         inode->i_mtime.tv_sec  = attr->mtime;
 258         inode->i_mtime.tv_nsec = attr->mtimensec;
 259         inode->i_ctime.tv_sec  = attr->ctime;
 260         inode->i_ctime.tv_nsec = attr->ctimensec;
 261         if (S_ISREG(inode->i_mode)) {
 262                 fuse_init_common(inode);
 263                 fuse_init_file_inode(inode);
 264         } else if (S_ISDIR(inode->i_mode))
 265                 fuse_init_dir(inode);
 266         else if (S_ISLNK(inode->i_mode))
 267                 fuse_init_symlink(inode);
 268         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 269                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 270                 fuse_init_common(inode);
 271                 init_special_inode(inode, inode->i_mode,
 272                                    new_decode_dev(attr->rdev));
 273         } else
 274                 BUG();
 275 }
 276
 277 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 278 {
 279         u64 nodeid = *(u64 *) _nodeidp;
 280         if (get_node_id(inode) == nodeid)
 281                 return 1;
 282         else
 283                 return 0;
 284 }
 285
 286 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 287 {
 288         u64 nodeid = *(u64 *) _nodeidp;
 289         get_fuse_inode(inode)->nodeid = nodeid;
 290         return 0;
 291 }
 292
 293 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 294                         int generation, struct fuse_attr *attr,
 295                         u64 attr_valid, u64 attr_version)
 296 {
 297         struct inode *inode;
 298         struct fuse_inode *fi;
 299         struct fuse_conn *fc = get_fuse_conn_super(sb);
 300
 301  retry:
 302         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 303         if (!inode)
 304                 return NULL;
 305
 306         if ((inode->i_state & I_NEW)) {
 307                 inode->i_flags |= S_NOATIME;
 308                 if (!fc->writeback_cache || !S_ISREG(attr->mode))
 309                         inode->i_flags |= S_NOCMTIME;
 310                 inode->i_generation = generation;
 311                 inode->i_data.backing_dev_info = &fc->bdi;
 312                 fuse_init_inode(inode, attr);
 313                 unlock_new_inode(inode);
 314         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 315                 /* Inode has changed type, any I/O on the old should fail */
 316                 make_bad_inode(inode);
 317                 iput(inode);
 318                 goto retry;
 319         }
 320
 321         fi = get_fuse_inode(inode);
 322         spin_lock(&fc->lock);
 323         fi->nlookup++;
 324         spin_unlock(&fc->lock);
 325         fuse_change_attributes(inode, attr, attr_valid, attr_version);
 326
 327         return inode;
 328 }
 329
 330 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 331                              loff_t offset, loff_t len)
 332 {
 333         struct inode *inode;
 334         pgoff_t pg_start;
 335         pgoff_t pg_end;
 336
 337         inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
 338         if (!inode)
 339                 return -ENOENT;
 340
 341         fuse_invalidate_attr(inode);
 342         if (offset >= 0) {
 343                 pg_start = offset >> PAGE_CACHE_SHIFT;
 344                 if (len <= 0)
 345                         pg_end = -1;
 346                 else
 347                         pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
 348                 invalidate_inode_pages2_range(inode->i_mapping,
 349                                               pg_start, pg_end);
 350         }
 351         iput(inode);
 352         return 0;
 353 }
 354
 355 static void fuse_umount_begin(struct super_block *sb)
 356 {
 357         fuse_abort_conn(get_fuse_conn_super(sb));
 358 }
 359
 360 static void fuse_send_destroy(struct fuse_conn *fc)
 361 {
 362         struct fuse_req *req = fc->destroy_req;
 363         if (req && fc->conn_init) {
 364                 fc->destroy_req = NULL;
 365                 req->in.h.opcode = FUSE_DESTROY;
 366                 req->force = 1;
 367                 req->background = 0;
 368                 fuse_request_send(fc, req);
 369                 fuse_put_request(fc, req);
 370         }
 371 }
 372
 373 static void fuse_bdi_destroy(struct fuse_conn *fc)
 374 {
 375         if (fc->bdi_initialized)
 376                 bdi_destroy(&fc->bdi);
 377 }
 378
 379 void fuse_conn_kill(struct fuse_conn *fc)
 380 {
 381         spin_lock(&fc->lock);
 382         fc->connected = 0;
 383         fc->blocked = 0;
 384         fc->initialized = 1;
 385         spin_unlock(&fc->lock);
 386         /* Flush all readers on this fs */
 387         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 388         wake_up_all(&fc->waitq);
 389         wake_up_all(&fc->blocked_waitq);
 390         wake_up_all(&fc->reserved_req_waitq);
 391 }
 392 EXPORT_SYMBOL_GPL(fuse_conn_kill);
 393
 394 static void fuse_put_super(struct super_block *sb)
 395 {
 396         struct fuse_conn *fc = get_fuse_conn_super(sb);
 397
 398         fuse_send_destroy(fc);
 399
 400         fuse_conn_kill(fc);
 401         mutex_lock(&fuse_mutex);
 402         list_del(&fc->entry);
 403         fuse_ctl_remove_conn(fc);
 404         mutex_unlock(&fuse_mutex);
 405         fuse_bdi_destroy(fc);
 406
 407         fuse_conn_put(fc);
 408 }
 409
 410 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 411 {
 412         stbuf->f_type    = FUSE_SUPER_MAGIC;
 413         stbuf->f_bsize   = attr->bsize;
 414         stbuf->f_frsize  = attr->frsize;
 415         stbuf->f_blocks  = attr->blocks;
 416         stbuf->f_bfree   = attr->bfree;
 417         stbuf->f_bavail  = attr->bavail;
 418         stbuf->f_files   = attr->files;
 419         stbuf->f_ffree   = attr->ffree;
 420         stbuf->f_namelen = attr->namelen;
 421         /* fsid is left zero */
 422 }
 423
 424 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 425 {
 426         struct super_block *sb = dentry->d_sb;
 427         struct fuse_conn *fc = get_fuse_conn_super(sb);
 428         struct fuse_req *req;
 429         struct fuse_statfs_out outarg;
 430         int err;
 431
 432         if (!fuse_allow_current_process(fc)) {
 433                 buf->f_type = FUSE_SUPER_MAGIC;
 434                 return 0;
 435         }
 436
 437         req = fuse_get_req_nopages(fc);
 438         if (IS_ERR(req))
 439                 return PTR_ERR(req);
 440
 441         memset(&outarg, 0, sizeof(outarg));
 442         req->in.numargs = 0;
 443         req->in.h.opcode = FUSE_STATFS;
 444         req->in.h.nodeid = get_node_id(dentry->d_inode);
 445         req->out.numargs = 1;
 446         req->out.args[0].size =
 447                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 448         req->out.args[0].value = &outarg;
 449         fuse_request_send(fc, req);
 450         err = req->out.h.error;
 451         if (!err)
 452                 convert_fuse_statfs(buf, &outarg.st);
 453         fuse_put_request(fc, req);
 454         return err;
 455 }
 456
 457 enum {
 458         OPT_FD,
 459         OPT_ROOTMODE,
 460         OPT_USER_ID,
 461         OPT_GROUP_ID,
 462         OPT_DEFAULT_PERMISSIONS,
 463         OPT_ALLOW_OTHER,
 464         OPT_MAX_READ,
 465         OPT_BLKSIZE,
 466         OPT_ERR
 467 };
 468
 469 static const match_table_t tokens = {
 470         {OPT_FD,                        "fd=%u"},
 471         {OPT_ROOTMODE,                  "rootmode=%o"},
 472         {OPT_USER_ID,                   "user_id=%u"},
 473         {OPT_GROUP_ID,                  "group_id=%u"},
 474         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 475         {OPT_ALLOW_OTHER,               "allow_other"},
 476         {OPT_MAX_READ,                  "max_read=%u"},
 477         {OPT_BLKSIZE,                   "blksize=%u"},
 478         {OPT_ERR,                       NULL}
 479 };
 480
 481 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 482 {
 483         char *p;
 484         memset(d, 0, sizeof(struct fuse_mount_data));
 485         d->max_read = ~0;
 486         d->blksize = FUSE_DEFAULT_BLKSIZE;
 487
 488         while ((p = strsep(&opt, ",")) != NULL) {
 489                 int token;
 490                 int value;
 491                 substring_t args[MAX_OPT_ARGS];
 492                 if (!*p)
 493                         continue;
 494
 495                 token = match_token(p, tokens, args);
 496                 switch (token) {
 497                 case OPT_FD:
 498                         if (match_int(&args[0], &value))
 499                                 return 0;
 500                         d->fd = value;
 501                         d->fd_present = 1;
 502                         break;
 503
 504                 case OPT_ROOTMODE:
 505                         if (match_octal(&args[0], &value))
 506                                 return 0;
 507                         if (!fuse_valid_type(value))
 508                                 return 0;
 509                         d->rootmode = value;
 510                         d->rootmode_present = 1;
 511                         break;
 512
 513                 case OPT_USER_ID:
 514                         if (match_int(&args[0], &value))
 515                                 return 0;
 516                         d->user_id = make_kuid(current_user_ns(), value);
 517                         if (!uid_valid(d->user_id))
 518                                 return 0;
 519                         d->user_id_present = 1;
 520                         break;
 521
 522                 case OPT_GROUP_ID:
 523                         if (match_int(&args[0], &value))
 524                                 return 0;
 525                         d->group_id = make_kgid(current_user_ns(), value);
 526                         if (!gid_valid(d->group_id))
 527                                 return 0;
 528                         d->group_id_present = 1;
 529                         break;
 530
 531                 case OPT_DEFAULT_PERMISSIONS:
 532                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 533                         break;
 534
 535                 case OPT_ALLOW_OTHER:
 536                         d->flags |= FUSE_ALLOW_OTHER;
 537                         break;
 538
 539                 case OPT_MAX_READ:
 540                         if (match_int(&args[0], &value))
 541                                 return 0;
 542                         d->max_read = value;
 543                         break;
 544
 545                 case OPT_BLKSIZE:
 546                         if (!is_bdev || match_int(&args[0], &value))
 547                                 return 0;
 548                         d->blksize = value;
 549                         break;
 550
 551                 default:
 552                         return 0;
 553                 }
 554         }
 555
 556         if (!d->fd_present || !d->rootmode_present ||
 557             !d->user_id_present || !d->group_id_present)
 558                 return 0;
 559
 560         return 1;
 561 }
 562
 563 static int fuse_show_options(struct seq_file *m, struct dentry *root)
 564 {
 565         struct super_block *sb = root->d_sb;
 566         struct fuse_conn *fc = get_fuse_conn_super(sb);
 567
 568         seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
 569         seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
 570         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 571                 seq_puts(m, ",default_permissions");
 572         if (fc->flags & FUSE_ALLOW_OTHER)
 573                 seq_puts(m, ",allow_other");
 574         if (fc->max_read != ~0)
 575                 seq_printf(m, ",max_read=%u", fc->max_read);
 576         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 577                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
 578         return 0;
 579 }
 580
 581 void fuse_conn_init(struct fuse_conn *fc)
 582 {
 583         memset(fc, 0, sizeof(*fc));
 584         spin_lock_init(&fc->lock);
 585         init_rwsem(&fc->killsb);
 586         atomic_set(&fc->count, 1);
 587         init_waitqueue_head(&fc->waitq);
 588         init_waitqueue_head(&fc->blocked_waitq);
 589         init_waitqueue_head(&fc->reserved_req_waitq);
 590         INIT_LIST_HEAD(&fc->pending);
 591         INIT_LIST_HEAD(&fc->processing);
 592         INIT_LIST_HEAD(&fc->io);
 593         INIT_LIST_HEAD(&fc->interrupts);
 594         INIT_LIST_HEAD(&fc->bg_queue);
 595         INIT_LIST_HEAD(&fc->entry);
 596         fc->forget_list_tail = &fc->forget_list_head;
 597         atomic_set(&fc->num_waiting, 0);
 598         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
 599         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
 600         fc->khctr = 0;
 601         fc->polled_files = RB_ROOT;
 602         fc->reqctr = 0;
 603         fc->blocked = 0;
 604         fc->initialized = 0;
 605         fc->attr_version = 1;
 606         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 607 }
 608 EXPORT_SYMBOL_GPL(fuse_conn_init);
 609
 610 void fuse_conn_put(struct fuse_conn *fc)
 611 {
 612         if (atomic_dec_and_test(&fc->count)) {
 613                 if (fc->destroy_req)
 614                         fuse_request_free(fc->destroy_req);
 615                 fc->release(fc);
 616         }
 617 }
 618 EXPORT_SYMBOL_GPL(fuse_conn_put);
 619
 620 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 621 {
 622         atomic_inc(&fc->count);
 623         return fc;
 624 }
 625 EXPORT_SYMBOL_GPL(fuse_conn_get);
 626
 627 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 628 {
 629         struct fuse_attr attr;
 630         memset(&attr, 0, sizeof(attr));
 631
 632         attr.mode = mode;
 633         attr.ino = FUSE_ROOT_ID;
 634         attr.nlink = 1;
 635         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 636 }
 637
 638 struct fuse_inode_handle {
 639         u64 nodeid;
 640         u32 generation;
 641 };
 642
 643 static struct dentry *fuse_get_dentry(struct super_block *sb,
 644                                       struct fuse_inode_handle *handle)
 645 {
 646         struct fuse_conn *fc = get_fuse_conn_super(sb);
 647         struct inode *inode;
 648         struct dentry *entry;
 649         int err = -ESTALE;
 650
 651         if (handle->nodeid == 0)
 652                 goto out_err;
 653
 654         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
 655         if (!inode) {
 656                 struct fuse_entry_out outarg;
 657                 struct qstr name;
 658
 659                 if (!fc->export_support)
 660                         goto out_err;
 661
 662                 name.len = 1;
 663                 name.name = ".";
 664                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
 665                                        &inode);
 666                 if (err && err != -ENOENT)
 667                         goto out_err;
 668                 if (err || !inode) {
 669                         err = -ESTALE;
 670                         goto out_err;
 671                 }
 672                 err = -EIO;
 673                 if (get_node_id(inode) != handle->nodeid)
 674                         goto out_iput;
 675         }
 676         err = -ESTALE;
 677         if (inode->i_generation != handle->generation)
 678                 goto out_iput;
 679
 680         entry = d_obtain_alias(inode);
 681         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
 682                 fuse_invalidate_entry_cache(entry);
 683
 684         return entry;
 685
 686  out_iput:
 687         iput(inode);
 688  out_err:
 689         return ERR_PTR(err);
 690 }
 691
 692 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 693                            struct inode *parent)
 694 {
 695         int len = parent ? 6 : 3;
 696         u64 nodeid;
 697         u32 generation;
 698
 699         if (*max_len < len) {
 700                 *max_len = len;
 701                 return  FILEID_INVALID;
 702         }
 703
 704         nodeid = get_fuse_inode(inode)->nodeid;
 705         generation = inode->i_generation;
 706
 707         fh[0] = (u32)(nodeid >> 32);
 708         fh[1] = (u32)(nodeid & 0xffffffff);
 709         fh[2] = generation;
 710
 711         if (parent) {
 712                 nodeid = get_fuse_inode(parent)->nodeid;
 713                 generation = parent->i_generation;
 714
 715                 fh[3] = (u32)(nodeid >> 32);
 716                 fh[4] = (u32)(nodeid & 0xffffffff);
 717                 fh[5] = generation;
 718         }
 719
 720         *max_len = len;
 721         return parent ? 0x82 : 0x81;
 722 }
 723
 724 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
 725                 struct fid *fid, int fh_len, int fh_type)
 726 {
 727         struct fuse_inode_handle handle;
 728
 729         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
 730                 return NULL;
 731
 732         handle.nodeid = (u64) fid->raw[0] << 32;
 733         handle.nodeid |= (u64) fid->raw[1];
 734         handle.generation = fid->raw[2];
 735         return fuse_get_dentry(sb, &handle);
 736 }
 737
 738 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
 739                 struct fid *fid, int fh_len, int fh_type)
 740 {
 741         struct fuse_inode_handle parent;
 742
 743         if (fh_type != 0x82 || fh_len < 6)
 744                 return NULL;
 745
 746         parent.nodeid = (u64) fid->raw[3] << 32;
 747         parent.nodeid |= (u64) fid->raw[4];
 748         parent.generation = fid->raw[5];
 749         return fuse_get_dentry(sb, &parent);
 750 }
 751
 752 static struct dentry *fuse_get_parent(struct dentry *child)
 753 {
 754         struct inode *child_inode = child->d_inode;
 755         struct fuse_conn *fc = get_fuse_conn(child_inode);
 756         struct inode *inode;
 757         struct dentry *parent;
 758         struct fuse_entry_out outarg;
 759         struct qstr name;
 760         int err;
 761
 762         if (!fc->export_support)
 763                 return ERR_PTR(-ESTALE);
 764
 765         name.len = 2;
 766         name.name = "..";
 767         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
 768                                &name, &outarg, &inode);
 769         if (err) {
 770                 if (err == -ENOENT)
 771                         return ERR_PTR(-ESTALE);
 772                 return ERR_PTR(err);
 773         }
 774
 775         parent = d_obtain_alias(inode);
 776         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
 777                 fuse_invalidate_entry_cache(parent);
 778
 779         return parent;
 780 }
 781
 782 static const struct export_operations fuse_export_operations = {
 783         .fh_to_dentry   = fuse_fh_to_dentry,
 784         .fh_to_parent   = fuse_fh_to_parent,
 785         .encode_fh      = fuse_encode_fh,
 786         .get_parent     = fuse_get_parent,
 787 };
 788
 789 static const struct super_operations fuse_super_operations = {
 790         .alloc_inode    = fuse_alloc_inode,
 791         .destroy_inode  = fuse_destroy_inode,
 792         .evict_inode    = fuse_evict_inode,
 793         .write_inode    = fuse_write_inode,
 794         .drop_inode     = generic_delete_inode,
 795         .remount_fs     = fuse_remount_fs,
 796         .put_super      = fuse_put_super,
 797         .umount_begin   = fuse_umount_begin,
 798         .statfs         = fuse_statfs,
 799         .show_options   = fuse_show_options,
 800 };
 801
 802 static void sanitize_global_limit(unsigned *limit)
 803 {
 804         if (*limit == 0)
 805                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
 806                          sizeof(struct fuse_req);
 807
 808         if (*limit >= 1 << 16)
 809                 *limit = (1 << 16) - 1;
 810 }
 811
 812 static int set_global_limit(const char *val, struct kernel_param *kp)
 813 {
 814         int rv;
 815
 816         rv = param_set_uint(val, kp);
 817         if (rv)
 818                 return rv;
 819
 820         sanitize_global_limit((unsigned *)kp->arg);
 821
 822         return 0;
 823 }
 824
 825 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
 826 {
 827         int cap_sys_admin = capable(CAP_SYS_ADMIN);
 828
 829         if (arg->minor < 13)
 830                 return;
 831
 832         sanitize_global_limit(&max_user_bgreq);
 833         sanitize_global_limit(&max_user_congthresh);
 834
 835         if (arg->max_background) {
 836                 fc->max_background = arg->max_background;
 837
 838                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
 839                         fc->max_background = max_user_bgreq;
 840         }
 841         if (arg->congestion_threshold) {
 842                 fc->congestion_threshold = arg->congestion_threshold;
 843
 844                 if (!cap_sys_admin &&
 845                     fc->congestion_threshold > max_user_congthresh)
 846                         fc->congestion_threshold = max_user_congthresh;
 847         }
 848 }
 849
 850 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 851 {
 852         struct fuse_init_out *arg = &req->misc.init_out;
 853
 854         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 855                 fc->conn_error = 1;
 856         else {
 857                 unsigned long ra_pages;
 858
 859                 process_init_limits(fc, arg);
 860
 861                 if (arg->minor >= 6) {
 862                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 863                         if (arg->flags & FUSE_ASYNC_READ)
 864                                 fc->async_read = 1;
 865                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 866                                 fc->no_lock = 1;
 867                         if (arg->minor >= 17) {
 868                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
 869                                         fc->no_flock = 1;
 870                         } else {
 871                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
 872                                         fc->no_flock = 1;
 873                         }
 874                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 875                                 fc->atomic_o_trunc = 1;
 876                         if (arg->minor >= 9) {
 877                                 /* LOOKUP has dependency on proto version */
 878                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
 879                                         fc->export_support = 1;
 880                         }
 881                         if (arg->flags & FUSE_BIG_WRITES)
 882                                 fc->big_writes = 1;
 883                         if (arg->flags & FUSE_DONT_MASK)
 884                                 fc->dont_mask = 1;
 885                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
 886                                 fc->auto_inval_data = 1;
 887                         if (arg->flags & FUSE_DO_READDIRPLUS) {
 888                                 fc->do_readdirplus = 1;
 889                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
 890                                         fc->readdirplus_auto = 1;
 891                         }
 892                         if (arg->flags & FUSE_ASYNC_DIO)
 893                                 fc->async_dio = 1;
 894                         if (arg->flags & FUSE_WRITEBACK_CACHE)
 895                                 fc->writeback_cache = 1;
 896                         if (arg->time_gran && arg->time_gran <= 1000000000)
 897                                 fc->sb->s_time_gran = arg->time_gran;
 898                         else
 899                                 fc->sb->s_time_gran = 1000000000;
 900
 901                 } else {
 902                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 903                         fc->no_lock = 1;
 904                         fc->no_flock = 1;
 905                 }
 906
 907                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 908                 fc->minor = arg->minor;
 909                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 910                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
 911                 fc->conn_init = 1;
 912         }
 913         fc->initialized = 1;
 914         wake_up_all(&fc->blocked_waitq);
 915 }
 916
 917 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 918 {
 919         struct fuse_init_in *arg = &req->misc.init_in;
 920
 921         arg->major = FUSE_KERNEL_VERSION;
 922         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 923         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 924         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
 925                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
 926                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
 927                 FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
 928                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
 929                 FUSE_WRITEBACK_CACHE;
 930         req->in.h.opcode = FUSE_INIT;
 931         req->in.numargs = 1;
 932         req->in.args[0].size = sizeof(*arg);
 933         req->in.args[0].value = arg;
 934         req->out.numargs = 1;
 935         /* Variable length argument used for backward compatibility
 936            with interface version < 7.5.  Rest of init_out is zeroed
 937            by do_get_request(), so a short reply is not a problem */
 938         req->out.argvar = 1;
 939         req->out.args[0].size = sizeof(struct fuse_init_out);
 940         req->out.args[0].value = &req->misc.init_out;
 941         req->end = process_init_reply;
 942         fuse_request_send_background(fc, req);
 943 }
 944
 945 static void fuse_free_conn(struct fuse_conn *fc)
 946 {
 947         kfree_rcu(fc, rcu);
 948 }
 949
 950 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 951 {
 952         int err;
 953
 954         fc->bdi.name = "fuse";
 955         fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 956         /* fuse does it's own writeback accounting */
 957         fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 958
 959         err = bdi_init(&fc->bdi);
 960         if (err)
 961                 return err;
 962
 963         fc->bdi_initialized = 1;
 964
 965         if (sb->s_bdev) {
 966                 err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
 967                                     MAJOR(fc->dev), MINOR(fc->dev));
 968         } else {
 969                 err = bdi_register_dev(&fc->bdi, fc->dev);
 970         }
 971
 972         if (err)
 973                 return err;
 974
 975         /*
 976          * For a single fuse filesystem use max 1% of dirty +
 977          * writeback threshold.
 978          *
 979          * This gives about 1M of write buffer for memory maps on a
 980          * machine with 1G and 10% dirty_ratio, which should be more
 981          * than enough.
 982          *
 983          * Privileged users can raise it by writing to
 984          *
 985          *    /sys/class/bdi/<bdi>/max_ratio
 986          */
 987         bdi_set_max_ratio(&fc->bdi, 1);
 988
 989         return 0;
 990 }
 991
 992 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 993 {
 994         struct fuse_conn *fc;
 995         struct inode *root;
 996         struct fuse_mount_data d;
 997         struct file *file;
 998         struct dentry *root_dentry;
 999         struct fuse_req *init_req;
1000         int err;
1001         int is_bdev = sb->s_bdev != NULL;
1002
1003         err = -EINVAL;
1004         if (sb->s_flags & MS_MANDLOCK)
1005                 goto err;
1006
1007         sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1008
1009         if (!parse_fuse_opt((char *) data, &d, is_bdev))
1010                 goto err;
1011
1012         if (is_bdev) {
1013 #ifdef CONFIG_BLOCK
1014                 err = -EINVAL;
1015                 if (!sb_set_blocksize(sb, d.blksize))
1016                         goto err;
1017 #endif
1018         } else {
1019                 sb->s_blocksize = PAGE_CACHE_SIZE;
1020                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1021         }
1022         sb->s_magic = FUSE_SUPER_MAGIC;
1023         sb->s_op = &fuse_super_operations;
1024         sb->s_maxbytes = MAX_LFS_FILESIZE;
1025         sb->s_time_gran = 1;
1026         sb->s_export_op = &fuse_export_operations;
1027
1028         file = fget(d.fd);
1029         err = -EINVAL;
1030         if (!file)
1031                 goto err;
1032
1033         if ((file->f_op != &fuse_dev_operations) ||
1034             (file->f_cred->user_ns != &init_user_ns))
1035                 goto err_fput;
1036
1037         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1038         err = -ENOMEM;
1039         if (!fc)
1040                 goto err_fput;
1041
1042         fuse_conn_init(fc);
1043
1044         fc->dev = sb->s_dev;
1045         fc->sb = sb;
1046         err = fuse_bdi_init(fc, sb);
1047         if (err)
1048                 goto err_put_conn;
1049
1050         sb->s_bdi = &fc->bdi;
1051
1052         /* Handle umasking inside the fuse code */
1053         if (sb->s_flags & MS_POSIXACL)
1054                 fc->dont_mask = 1;
1055         sb->s_flags |= MS_POSIXACL;
1056
1057         fc->release = fuse_free_conn;
1058         fc->flags = d.flags;
1059         fc->user_id = d.user_id;
1060         fc->group_id = d.group_id;
1061         fc->max_read = max_t(unsigned, 4096, d.max_read);
1062
1063         /* Used by get_root_inode() */
1064         sb->s_fs_info = fc;
1065
1066         err = -ENOMEM;
1067         root = fuse_get_root_inode(sb, d.rootmode);
1068         root_dentry = d_make_root(root);
1069         if (!root_dentry)
1070                 goto err_put_conn;
1071         /* only now - we want root dentry with NULL ->d_op */
1072         sb->s_d_op = &fuse_dentry_operations;
1073
1074         init_req = fuse_request_alloc(0);
1075         if (!init_req)
1076                 goto err_put_root;
1077         init_req->background = 1;
1078
1079         if (is_bdev) {
1080                 fc->destroy_req = fuse_request_alloc(0);
1081                 if (!fc->destroy_req)
1082                         goto err_free_init_req;
1083         }
1084
1085         mutex_lock(&fuse_mutex);
1086         err = -EINVAL;
1087         if (file->private_data)
1088                 goto err_unlock;
1089
1090         err = fuse_ctl_add_conn(fc);
1091         if (err)
1092                 goto err_unlock;
1093
1094         list_add_tail(&fc->entry, &fuse_conn_list);
1095         sb->s_root = root_dentry;
1096         fc->connected = 1;
1097         file->private_data = fuse_conn_get(fc);
1098         mutex_unlock(&fuse_mutex);
1099         /*
1100          * atomic_dec_and_test() in fput() provides the necessary
1101          * memory barrier for file->private_data to be visible on all
1102          * CPUs after this
1103          */
1104         fput(file);
1105
1106         fuse_send_init(fc, init_req);
1107
1108         return 0;
1109
1110  err_unlock:
1111         mutex_unlock(&fuse_mutex);
1112  err_free_init_req:
1113         fuse_request_free(init_req);
1114  err_put_root:
1115         dput(root_dentry);
1116  err_put_conn:
1117         fuse_bdi_destroy(fc);
1118         fuse_conn_put(fc);
1119  err_fput:
1120         fput(file);
1121  err:
1122         return err;
1123 }
1124
1125 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1126                        int flags, const char *dev_name,
1127                        void *raw_data)
1128 {
1129         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1130 }
1131
1132 static void fuse_kill_sb_anon(struct super_block *sb)
1133 {
1134         struct fuse_conn *fc = get_fuse_conn_super(sb);
1135
1136         if (fc) {
1137                 down_write(&fc->killsb);
1138                 fc->sb = NULL;
1139                 up_write(&fc->killsb);
1140         }
1141
1142         kill_anon_super(sb);
1143 }
1144
1145 static struct file_system_type fuse_fs_type = {
1146         .owner          = THIS_MODULE,
1147         .name           = "fuse",
1148         .fs_flags       = FS_HAS_SUBTYPE,
1149         .mount          = fuse_mount,
1150         .kill_sb        = fuse_kill_sb_anon,
1151 };
1152 MODULE_ALIAS_FS("fuse");
1153
1154 #ifdef CONFIG_BLOCK
1155 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1156                            int flags, const char *dev_name,
1157                            void *raw_data)
1158 {
1159         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1160 }
1161
1162 static void fuse_kill_sb_blk(struct super_block *sb)
1163 {
1164         struct fuse_conn *fc = get_fuse_conn_super(sb);
1165
1166         if (fc) {
1167                 down_write(&fc->killsb);
1168                 fc->sb = NULL;
1169                 up_write(&fc->killsb);
1170         }
1171
1172         kill_block_super(sb);
1173 }
1174
1175 static struct file_system_type fuseblk_fs_type = {
1176         .owner          = THIS_MODULE,
1177         .name           = "fuseblk",
1178         .mount          = fuse_mount_blk,
1179         .kill_sb        = fuse_kill_sb_blk,
1180         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1181 };
1182 MODULE_ALIAS_FS("fuseblk");
1183
1184 static inline int register_fuseblk(void)
1185 {
1186         return register_filesystem(&fuseblk_fs_type);
1187 }
1188
1189 static inline void unregister_fuseblk(void)
1190 {
1191         unregister_filesystem(&fuseblk_fs_type);
1192 }
1193 #else
1194 static inline int register_fuseblk(void)
1195 {
1196         return 0;
1197 }
1198
1199 static inline void unregister_fuseblk(void)
1200 {
1201 }
1202 #endif
1203
1204 static void fuse_inode_init_once(void *foo)
1205 {
1206         struct inode *inode = foo;
1207
1208         inode_init_once(inode);
1209 }
1210
1211 static int __init fuse_fs_init(void)
1212 {
1213         int err;
1214
1215         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1216                                               sizeof(struct fuse_inode),
1217                                               0, SLAB_HWCACHE_ALIGN,
1218                                               fuse_inode_init_once);
1219         err = -ENOMEM;
1220         if (!fuse_inode_cachep)
1221                 goto out;
1222
1223         err = register_fuseblk();
1224         if (err)
1225                 goto out2;
1226
1227         err = register_filesystem(&fuse_fs_type);
1228         if (err)
1229                 goto out3;
1230
1231         return 0;
1232
1233  out3:
1234         unregister_fuseblk();
1235  out2:
1236         kmem_cache_destroy(fuse_inode_cachep);
1237  out:
1238         return err;
1239 }
1240
1241 static void fuse_fs_cleanup(void)
1242 {
1243         unregister_filesystem(&fuse_fs_type);
1244         unregister_fuseblk();
1245
1246         /*
1247          * Make sure all delayed rcu free inodes are flushed before we
1248          * destroy cache.
1249          */
1250         rcu_barrier();
1251         kmem_cache_destroy(fuse_inode_cachep);
1252 }
1253
1254 static struct kobject *fuse_kobj;
1255 static struct kobject *connections_kobj;
1256
1257 static int fuse_sysfs_init(void)
1258 {
1259         int err;
1260
1261         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1262         if (!fuse_kobj) {
1263                 err = -ENOMEM;
1264                 goto out_err;
1265         }
1266
1267         connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1268         if (!connections_kobj) {
1269                 err = -ENOMEM;
1270                 goto out_fuse_unregister;
1271         }
1272
1273         return 0;
1274
1275  out_fuse_unregister:
1276         kobject_put(fuse_kobj);
1277  out_err:
1278         return err;
1279 }
1280
1281 static void fuse_sysfs_cleanup(void)
1282 {
1283         kobject_put(connections_kobj);
1284         kobject_put(fuse_kobj);
1285 }
1286
1287 static int __init fuse_init(void)
1288 {
1289         int res;
1290
1291         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1292                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1293
1294         INIT_LIST_HEAD(&fuse_conn_list);
1295         res = fuse_fs_init();
1296         if (res)
1297                 goto err;
1298
1299         res = fuse_dev_init();
1300         if (res)
1301                 goto err_fs_cleanup;
1302
1303         res = fuse_sysfs_init();
1304         if (res)
1305                 goto err_dev_cleanup;
1306
1307         res = fuse_ctl_init();
1308         if (res)
1309                 goto err_sysfs_cleanup;
1310
1311         sanitize_global_limit(&max_user_bgreq);
1312         sanitize_global_limit(&max_user_congthresh);
1313
1314         return 0;
1315
1316  err_sysfs_cleanup:
1317         fuse_sysfs_cleanup();
1318  err_dev_cleanup:
1319         fuse_dev_cleanup();
1320  err_fs_cleanup:
1321         fuse_fs_cleanup();
1322  err:
1323         return res;
1324 }
1325
1326 static void __exit fuse_exit(void)
1327 {
1328         printk(KERN_DEBUG "fuse exit\n");
1329
1330         fuse_ctl_cleanup();
1331         fuse_sysfs_cleanup();
1332         fuse_fs_cleanup();
1333         fuse_dev_cleanup();
1334 }
1335
1336 module_init(fuse_init);
1337 module_exit(fuse_exit);