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 fuse_match_uint(substring_t *s, unsigned int *res)
 482 {
 483         int err = -ENOMEM;
 484         char *buf = match_strdup(s);
 485         if (buf) {
 486                 err = kstrtouint(buf, 10, res);
 487                 kfree(buf);
 488         }
 489         return err;
 490 }
 491
 492 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 493 {
 494         char *p;
 495         memset(d, 0, sizeof(struct fuse_mount_data));
 496         d->max_read = ~0;
 497         d->blksize = FUSE_DEFAULT_BLKSIZE;
 498
 499         while ((p = strsep(&opt, ",")) != NULL) {
 500                 int token;
 501                 int value;
 502                 unsigned uv;
 503                 substring_t args[MAX_OPT_ARGS];
 504                 if (!*p)
 505                         continue;
 506
 507                 token = match_token(p, tokens, args);
 508                 switch (token) {
 509                 case OPT_FD:
 510                         if (match_int(&args[0], &value))
 511                                 return 0;
 512                         d->fd = value;
 513                         d->fd_present = 1;
 514                         break;
 515
 516                 case OPT_ROOTMODE:
 517                         if (match_octal(&args[0], &value))
 518                                 return 0;
 519                         if (!fuse_valid_type(value))
 520                                 return 0;
 521                         d->rootmode = value;
 522                         d->rootmode_present = 1;
 523                         break;
 524
 525                 case OPT_USER_ID:
 526                         if (fuse_match_uint(&args[0], &uv))
 527                                 return 0;
 528                         d->user_id = make_kuid(current_user_ns(), uv);
 529                         if (!uid_valid(d->user_id))
 530                                 return 0;
 531                         d->user_id_present = 1;
 532                         break;
 533
 534                 case OPT_GROUP_ID:
 535                         if (fuse_match_uint(&args[0], &uv))
 536                                 return 0;
 537                         d->group_id = make_kgid(current_user_ns(), uv);
 538                         if (!gid_valid(d->group_id))
 539                                 return 0;
 540                         d->group_id_present = 1;
 541                         break;
 542
 543                 case OPT_DEFAULT_PERMISSIONS:
 544                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 545                         break;
 546
 547                 case OPT_ALLOW_OTHER:
 548                         d->flags |= FUSE_ALLOW_OTHER;
 549                         break;
 550
 551                 case OPT_MAX_READ:
 552                         if (match_int(&args[0], &value))
 553                                 return 0;
 554                         d->max_read = value;
 555                         break;
 556
 557                 case OPT_BLKSIZE:
 558                         if (!is_bdev || match_int(&args[0], &value))
 559                                 return 0;
 560                         d->blksize = value;
 561                         break;
 562
 563                 default:
 564                         return 0;
 565                 }
 566         }
 567
 568         if (!d->fd_present || !d->rootmode_present ||
 569             !d->user_id_present || !d->group_id_present)
 570                 return 0;
 571
 572         return 1;
 573 }
 574
 575 static int fuse_show_options(struct seq_file *m, struct dentry *root)
 576 {
 577         struct super_block *sb = root->d_sb;
 578         struct fuse_conn *fc = get_fuse_conn_super(sb);
 579
 580         seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
 581         seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
 582         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 583                 seq_puts(m, ",default_permissions");
 584         if (fc->flags & FUSE_ALLOW_OTHER)
 585                 seq_puts(m, ",allow_other");
 586         if (fc->max_read != ~0)
 587                 seq_printf(m, ",max_read=%u", fc->max_read);
 588         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 589                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
 590         return 0;
 591 }
 592
 593 void fuse_conn_init(struct fuse_conn *fc)
 594 {
 595         memset(fc, 0, sizeof(*fc));
 596         spin_lock_init(&fc->lock);
 597         init_rwsem(&fc->killsb);
 598         atomic_set(&fc->count, 1);
 599         init_waitqueue_head(&fc->waitq);
 600         init_waitqueue_head(&fc->blocked_waitq);
 601         init_waitqueue_head(&fc->reserved_req_waitq);
 602         INIT_LIST_HEAD(&fc->pending);
 603         INIT_LIST_HEAD(&fc->processing);
 604         INIT_LIST_HEAD(&fc->io);
 605         INIT_LIST_HEAD(&fc->interrupts);
 606         INIT_LIST_HEAD(&fc->bg_queue);
 607         INIT_LIST_HEAD(&fc->entry);
 608         fc->forget_list_tail = &fc->forget_list_head;
 609         atomic_set(&fc->num_waiting, 0);
 610         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
 611         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
 612         fc->khctr = 0;
 613         fc->polled_files = RB_ROOT;
 614         fc->reqctr = 0;
 615         fc->blocked = 0;
 616         fc->initialized = 0;
 617         fc->attr_version = 1;
 618         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 619 }
 620 EXPORT_SYMBOL_GPL(fuse_conn_init);
 621
 622 void fuse_conn_put(struct fuse_conn *fc)
 623 {
 624         if (atomic_dec_and_test(&fc->count)) {
 625                 if (fc->destroy_req)
 626                         fuse_request_free(fc->destroy_req);
 627                 fc->release(fc);
 628         }
 629 }
 630 EXPORT_SYMBOL_GPL(fuse_conn_put);
 631
 632 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 633 {
 634         atomic_inc(&fc->count);
 635         return fc;
 636 }
 637 EXPORT_SYMBOL_GPL(fuse_conn_get);
 638
 639 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 640 {
 641         struct fuse_attr attr;
 642         memset(&attr, 0, sizeof(attr));
 643
 644         attr.mode = mode;
 645         attr.ino = FUSE_ROOT_ID;
 646         attr.nlink = 1;
 647         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 648 }
 649
 650 struct fuse_inode_handle {
 651         u64 nodeid;
 652         u32 generation;
 653 };
 654
 655 static struct dentry *fuse_get_dentry(struct super_block *sb,
 656                                       struct fuse_inode_handle *handle)
 657 {
 658         struct fuse_conn *fc = get_fuse_conn_super(sb);
 659         struct inode *inode;
 660         struct dentry *entry;
 661         int err = -ESTALE;
 662
 663         if (handle->nodeid == 0)
 664                 goto out_err;
 665
 666         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
 667         if (!inode) {
 668                 struct fuse_entry_out outarg;
 669                 struct qstr name;
 670
 671                 if (!fc->export_support)
 672                         goto out_err;
 673
 674                 name.len = 1;
 675                 name.name = ".";
 676                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
 677                                        &inode);
 678                 if (err && err != -ENOENT)
 679                         goto out_err;
 680                 if (err || !inode) {
 681                         err = -ESTALE;
 682                         goto out_err;
 683                 }
 684                 err = -EIO;
 685                 if (get_node_id(inode) != handle->nodeid)
 686                         goto out_iput;
 687         }
 688         err = -ESTALE;
 689         if (inode->i_generation != handle->generation)
 690                 goto out_iput;
 691
 692         entry = d_obtain_alias(inode);
 693         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
 694                 fuse_invalidate_entry_cache(entry);
 695
 696         return entry;
 697
 698  out_iput:
 699         iput(inode);
 700  out_err:
 701         return ERR_PTR(err);
 702 }
 703
 704 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 705                            struct inode *parent)
 706 {
 707         int len = parent ? 6 : 3;
 708         u64 nodeid;
 709         u32 generation;
 710
 711         if (*max_len < len) {
 712                 *max_len = len;
 713                 return  FILEID_INVALID;
 714         }
 715
 716         nodeid = get_fuse_inode(inode)->nodeid;
 717         generation = inode->i_generation;
 718
 719         fh[0] = (u32)(nodeid >> 32);
 720         fh[1] = (u32)(nodeid & 0xffffffff);
 721         fh[2] = generation;
 722
 723         if (parent) {
 724                 nodeid = get_fuse_inode(parent)->nodeid;
 725                 generation = parent->i_generation;
 726
 727                 fh[3] = (u32)(nodeid >> 32);
 728                 fh[4] = (u32)(nodeid & 0xffffffff);
 729                 fh[5] = generation;
 730         }
 731
 732         *max_len = len;
 733         return parent ? 0x82 : 0x81;
 734 }
 735
 736 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
 737                 struct fid *fid, int fh_len, int fh_type)
 738 {
 739         struct fuse_inode_handle handle;
 740
 741         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
 742                 return NULL;
 743
 744         handle.nodeid = (u64) fid->raw[0] << 32;
 745         handle.nodeid |= (u64) fid->raw[1];
 746         handle.generation = fid->raw[2];
 747         return fuse_get_dentry(sb, &handle);
 748 }
 749
 750 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
 751                 struct fid *fid, int fh_len, int fh_type)
 752 {
 753         struct fuse_inode_handle parent;
 754
 755         if (fh_type != 0x82 || fh_len < 6)
 756                 return NULL;
 757
 758         parent.nodeid = (u64) fid->raw[3] << 32;
 759         parent.nodeid |= (u64) fid->raw[4];
 760         parent.generation = fid->raw[5];
 761         return fuse_get_dentry(sb, &parent);
 762 }
 763
 764 static struct dentry *fuse_get_parent(struct dentry *child)
 765 {
 766         struct inode *child_inode = child->d_inode;
 767         struct fuse_conn *fc = get_fuse_conn(child_inode);
 768         struct inode *inode;
 769         struct dentry *parent;
 770         struct fuse_entry_out outarg;
 771         struct qstr name;
 772         int err;
 773
 774         if (!fc->export_support)
 775                 return ERR_PTR(-ESTALE);
 776
 777         name.len = 2;
 778         name.name = "..";
 779         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
 780                                &name, &outarg, &inode);
 781         if (err) {
 782                 if (err == -ENOENT)
 783                         return ERR_PTR(-ESTALE);
 784                 return ERR_PTR(err);
 785         }
 786
 787         parent = d_obtain_alias(inode);
 788         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
 789                 fuse_invalidate_entry_cache(parent);
 790
 791         return parent;
 792 }
 793
 794 static const struct export_operations fuse_export_operations = {
 795         .fh_to_dentry   = fuse_fh_to_dentry,
 796         .fh_to_parent   = fuse_fh_to_parent,
 797         .encode_fh      = fuse_encode_fh,
 798         .get_parent     = fuse_get_parent,
 799 };
 800
 801 static const struct super_operations fuse_super_operations = {
 802         .alloc_inode    = fuse_alloc_inode,
 803         .destroy_inode  = fuse_destroy_inode,
 804         .evict_inode    = fuse_evict_inode,
 805         .write_inode    = fuse_write_inode,
 806         .drop_inode     = generic_delete_inode,
 807         .remount_fs     = fuse_remount_fs,
 808         .put_super      = fuse_put_super,
 809         .umount_begin   = fuse_umount_begin,
 810         .statfs         = fuse_statfs,
 811         .show_options   = fuse_show_options,
 812 };
 813
 814 static void sanitize_global_limit(unsigned *limit)
 815 {
 816         if (*limit == 0)
 817                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
 818                          sizeof(struct fuse_req);
 819
 820         if (*limit >= 1 << 16)
 821                 *limit = (1 << 16) - 1;
 822 }
 823
 824 static int set_global_limit(const char *val, struct kernel_param *kp)
 825 {
 826         int rv;
 827
 828         rv = param_set_uint(val, kp);
 829         if (rv)
 830                 return rv;
 831
 832         sanitize_global_limit((unsigned *)kp->arg);
 833
 834         return 0;
 835 }
 836
 837 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
 838 {
 839         int cap_sys_admin = capable(CAP_SYS_ADMIN);
 840
 841         if (arg->minor < 13)
 842                 return;
 843
 844         sanitize_global_limit(&max_user_bgreq);
 845         sanitize_global_limit(&max_user_congthresh);
 846
 847         if (arg->max_background) {
 848                 fc->max_background = arg->max_background;
 849
 850                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
 851                         fc->max_background = max_user_bgreq;
 852         }
 853         if (arg->congestion_threshold) {
 854                 fc->congestion_threshold = arg->congestion_threshold;
 855
 856                 if (!cap_sys_admin &&
 857                     fc->congestion_threshold > max_user_congthresh)
 858                         fc->congestion_threshold = max_user_congthresh;
 859         }
 860 }
 861
 862 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 863 {
 864         struct fuse_init_out *arg = &req->misc.init_out;
 865
 866         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 867                 fc->conn_error = 1;
 868         else {
 869                 unsigned long ra_pages;
 870
 871                 process_init_limits(fc, arg);
 872
 873                 if (arg->minor >= 6) {
 874                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 875                         if (arg->flags & FUSE_ASYNC_READ)
 876                                 fc->async_read = 1;
 877                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 878                                 fc->no_lock = 1;
 879                         if (arg->minor >= 17) {
 880                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
 881                                         fc->no_flock = 1;
 882                         } else {
 883                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
 884                                         fc->no_flock = 1;
 885                         }
 886                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 887                                 fc->atomic_o_trunc = 1;
 888                         if (arg->minor >= 9) {
 889                                 /* LOOKUP has dependency on proto version */
 890                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
 891                                         fc->export_support = 1;
 892                         }
 893                         if (arg->flags & FUSE_BIG_WRITES)
 894                                 fc->big_writes = 1;
 895                         if (arg->flags & FUSE_DONT_MASK)
 896                                 fc->dont_mask = 1;
 897                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
 898                                 fc->auto_inval_data = 1;
 899                         if (arg->flags & FUSE_DO_READDIRPLUS) {
 900                                 fc->do_readdirplus = 1;
 901                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
 902                                         fc->readdirplus_auto = 1;
 903                         }
 904                         if (arg->flags & FUSE_ASYNC_DIO)
 905                                 fc->async_dio = 1;
 906                         if (arg->flags & FUSE_WRITEBACK_CACHE)
 907                                 fc->writeback_cache = 1;
 908                         if (arg->time_gran && arg->time_gran <= 1000000000)
 909                                 fc->sb->s_time_gran = arg->time_gran;
 910                 } else {
 911                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 912                         fc->no_lock = 1;
 913                         fc->no_flock = 1;
 914                 }
 915
 916                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 917                 fc->minor = arg->minor;
 918                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 919                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
 920                 fc->conn_init = 1;
 921         }
 922         fc->initialized = 1;
 923         wake_up_all(&fc->blocked_waitq);
 924 }
 925
 926 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 927 {
 928         struct fuse_init_in *arg = &req->misc.init_in;
 929
 930         arg->major = FUSE_KERNEL_VERSION;
 931         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 932         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 933         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
 934                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
 935                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
 936                 FUSE_FLOCK_LOCKS | FUSE_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
 937                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
 938                 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT;
 939         req->in.h.opcode = FUSE_INIT;
 940         req->in.numargs = 1;
 941         req->in.args[0].size = sizeof(*arg);
 942         req->in.args[0].value = arg;
 943         req->out.numargs = 1;
 944         /* Variable length argument used for backward compatibility
 945            with interface version < 7.5.  Rest of init_out is zeroed
 946            by do_get_request(), so a short reply is not a problem */
 947         req->out.argvar = 1;
 948         req->out.args[0].size = sizeof(struct fuse_init_out);
 949         req->out.args[0].value = &req->misc.init_out;
 950         req->end = process_init_reply;
 951         fuse_request_send_background(fc, req);
 952 }
 953
 954 static void fuse_free_conn(struct fuse_conn *fc)
 955 {
 956         kfree_rcu(fc, rcu);
 957 }
 958
 959 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 960 {
 961         int err;
 962
 963         fc->bdi.name = "fuse";
 964         fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 965         /* fuse does it's own writeback accounting */
 966         fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 967
 968         err = bdi_init(&fc->bdi);
 969         if (err)
 970                 return err;
 971
 972         fc->bdi_initialized = 1;
 973
 974         if (sb->s_bdev) {
 975                 err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
 976                                     MAJOR(fc->dev), MINOR(fc->dev));
 977         } else {
 978                 err = bdi_register_dev(&fc->bdi, fc->dev);
 979         }
 980
 981         if (err)
 982                 return err;
 983
 984         /*
 985          * For a single fuse filesystem use max 1% of dirty +
 986          * writeback threshold.
 987          *
 988          * This gives about 1M of write buffer for memory maps on a
 989          * machine with 1G and 10% dirty_ratio, which should be more
 990          * than enough.
 991          *
 992          * Privileged users can raise it by writing to
 993          *
 994          *    /sys/class/bdi/<bdi>/max_ratio
 995          */
 996         bdi_set_max_ratio(&fc->bdi, 1);
 997
 998         return 0;
 999 }
1000
1001 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1002 {
1003         struct fuse_conn *fc;
1004         struct inode *root;
1005         struct fuse_mount_data d;
1006         struct file *file;
1007         struct dentry *root_dentry;
1008         struct fuse_req *init_req;
1009         int err;
1010         int is_bdev = sb->s_bdev != NULL;
1011
1012         err = -EINVAL;
1013         if (sb->s_flags & MS_MANDLOCK)
1014                 goto err;
1015
1016         sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1017
1018         if (!parse_fuse_opt(data, &d, is_bdev))
1019                 goto err;
1020
1021         if (is_bdev) {
1022 #ifdef CONFIG_BLOCK
1023                 err = -EINVAL;
1024                 if (!sb_set_blocksize(sb, d.blksize))
1025                         goto err;
1026 #endif
1027         } else {
1028                 sb->s_blocksize = PAGE_CACHE_SIZE;
1029                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
1030         }
1031         sb->s_magic = FUSE_SUPER_MAGIC;
1032         sb->s_op = &fuse_super_operations;
1033         sb->s_maxbytes = MAX_LFS_FILESIZE;
1034         sb->s_time_gran = 1;
1035         sb->s_export_op = &fuse_export_operations;
1036
1037         file = fget(d.fd);
1038         err = -EINVAL;
1039         if (!file)
1040                 goto err;
1041
1042         if ((file->f_op != &fuse_dev_operations) ||
1043             (file->f_cred->user_ns != &init_user_ns))
1044                 goto err_fput;
1045
1046         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1047         err = -ENOMEM;
1048         if (!fc)
1049                 goto err_fput;
1050
1051         fuse_conn_init(fc);
1052
1053         fc->dev = sb->s_dev;
1054         fc->sb = sb;
1055         err = fuse_bdi_init(fc, sb);
1056         if (err)
1057                 goto err_put_conn;
1058
1059         sb->s_bdi = &fc->bdi;
1060
1061         /* Handle umasking inside the fuse code */
1062         if (sb->s_flags & MS_POSIXACL)
1063                 fc->dont_mask = 1;
1064         sb->s_flags |= MS_POSIXACL;
1065
1066         fc->release = fuse_free_conn;
1067         fc->flags = d.flags;
1068         fc->user_id = d.user_id;
1069         fc->group_id = d.group_id;
1070         fc->max_read = max_t(unsigned, 4096, d.max_read);
1071
1072         /* Used by get_root_inode() */
1073         sb->s_fs_info = fc;
1074
1075         err = -ENOMEM;
1076         root = fuse_get_root_inode(sb, d.rootmode);
1077         root_dentry = d_make_root(root);
1078         if (!root_dentry)
1079                 goto err_put_conn;
1080         /* only now - we want root dentry with NULL ->d_op */
1081         sb->s_d_op = &fuse_dentry_operations;
1082
1083         init_req = fuse_request_alloc(0);
1084         if (!init_req)
1085                 goto err_put_root;
1086         init_req->background = 1;
1087
1088         if (is_bdev) {
1089                 fc->destroy_req = fuse_request_alloc(0);
1090                 if (!fc->destroy_req)
1091                         goto err_free_init_req;
1092         }
1093
1094         mutex_lock(&fuse_mutex);
1095         err = -EINVAL;
1096         if (file->private_data)
1097                 goto err_unlock;
1098
1099         err = fuse_ctl_add_conn(fc);
1100         if (err)
1101                 goto err_unlock;
1102
1103         list_add_tail(&fc->entry, &fuse_conn_list);
1104         sb->s_root = root_dentry;
1105         fc->connected = 1;
1106         file->private_data = fuse_conn_get(fc);
1107         mutex_unlock(&fuse_mutex);
1108         /*
1109          * atomic_dec_and_test() in fput() provides the necessary
1110          * memory barrier for file->private_data to be visible on all
1111          * CPUs after this
1112          */
1113         fput(file);
1114
1115         fuse_send_init(fc, init_req);
1116
1117         return 0;
1118
1119  err_unlock:
1120         mutex_unlock(&fuse_mutex);
1121  err_free_init_req:
1122         fuse_request_free(init_req);
1123  err_put_root:
1124         dput(root_dentry);
1125  err_put_conn:
1126         fuse_bdi_destroy(fc);
1127         fuse_conn_put(fc);
1128  err_fput:
1129         fput(file);
1130  err:
1131         return err;
1132 }
1133
1134 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1135                        int flags, const char *dev_name,
1136                        void *raw_data)
1137 {
1138         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1139 }
1140
1141 static void fuse_kill_sb_anon(struct super_block *sb)
1142 {
1143         struct fuse_conn *fc = get_fuse_conn_super(sb);
1144
1145         if (fc) {
1146                 down_write(&fc->killsb);
1147                 fc->sb = NULL;
1148                 up_write(&fc->killsb);
1149         }
1150
1151         kill_anon_super(sb);
1152 }
1153
1154 static struct file_system_type fuse_fs_type = {
1155         .owner          = THIS_MODULE,
1156         .name           = "fuse",
1157         .fs_flags       = FS_HAS_SUBTYPE,
1158         .mount          = fuse_mount,
1159         .kill_sb        = fuse_kill_sb_anon,
1160 };
1161 MODULE_ALIAS_FS("fuse");
1162
1163 #ifdef CONFIG_BLOCK
1164 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1165                            int flags, const char *dev_name,
1166                            void *raw_data)
1167 {
1168         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1169 }
1170
1171 static void fuse_kill_sb_blk(struct super_block *sb)
1172 {
1173         struct fuse_conn *fc = get_fuse_conn_super(sb);
1174
1175         if (fc) {
1176                 down_write(&fc->killsb);
1177                 fc->sb = NULL;
1178                 up_write(&fc->killsb);
1179         }
1180
1181         kill_block_super(sb);
1182 }
1183
1184 static struct file_system_type fuseblk_fs_type = {
1185         .owner          = THIS_MODULE,
1186         .name           = "fuseblk",
1187         .mount          = fuse_mount_blk,
1188         .kill_sb        = fuse_kill_sb_blk,
1189         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1190 };
1191 MODULE_ALIAS_FS("fuseblk");
1192
1193 static inline int register_fuseblk(void)
1194 {
1195         return register_filesystem(&fuseblk_fs_type);
1196 }
1197
1198 static inline void unregister_fuseblk(void)
1199 {
1200         unregister_filesystem(&fuseblk_fs_type);
1201 }
1202 #else
1203 static inline int register_fuseblk(void)
1204 {
1205         return 0;
1206 }
1207
1208 static inline void unregister_fuseblk(void)
1209 {
1210 }
1211 #endif
1212
1213 static void fuse_inode_init_once(void *foo)
1214 {
1215         struct inode *inode = foo;
1216
1217         inode_init_once(inode);
1218 }
1219
1220 static int __init fuse_fs_init(void)
1221 {
1222         int err;
1223
1224         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1225                                               sizeof(struct fuse_inode),
1226                                               0, SLAB_HWCACHE_ALIGN,
1227                                               fuse_inode_init_once);
1228         err = -ENOMEM;
1229         if (!fuse_inode_cachep)
1230                 goto out;
1231
1232         err = register_fuseblk();
1233         if (err)
1234                 goto out2;
1235
1236         err = register_filesystem(&fuse_fs_type);
1237         if (err)
1238                 goto out3;
1239
1240         return 0;
1241
1242  out3:
1243         unregister_fuseblk();
1244  out2:
1245         kmem_cache_destroy(fuse_inode_cachep);
1246  out:
1247         return err;
1248 }
1249
1250 static void fuse_fs_cleanup(void)
1251 {
1252         unregister_filesystem(&fuse_fs_type);
1253         unregister_fuseblk();
1254
1255         /*
1256          * Make sure all delayed rcu free inodes are flushed before we
1257          * destroy cache.
1258          */
1259         rcu_barrier();
1260         kmem_cache_destroy(fuse_inode_cachep);
1261 }
1262
1263 static struct kobject *fuse_kobj;
1264 static struct kobject *connections_kobj;
1265
1266 static int fuse_sysfs_init(void)
1267 {
1268         int err;
1269
1270         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1271         if (!fuse_kobj) {
1272                 err = -ENOMEM;
1273                 goto out_err;
1274         }
1275
1276         connections_kobj = kobject_create_and_add("connections", fuse_kobj);
1277         if (!connections_kobj) {
1278                 err = -ENOMEM;
1279                 goto out_fuse_unregister;
1280         }
1281
1282         return 0;
1283
1284  out_fuse_unregister:
1285         kobject_put(fuse_kobj);
1286  out_err:
1287         return err;
1288 }
1289
1290 static void fuse_sysfs_cleanup(void)
1291 {
1292         kobject_put(connections_kobj);
1293         kobject_put(fuse_kobj);
1294 }
1295
1296 static int __init fuse_init(void)
1297 {
1298         int res;
1299
1300         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1301                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1302
1303         INIT_LIST_HEAD(&fuse_conn_list);
1304         res = fuse_fs_init();
1305         if (res)
1306                 goto err;
1307
1308         res = fuse_dev_init();
1309         if (res)
1310                 goto err_fs_cleanup;
1311
1312         res = fuse_sysfs_init();
1313         if (res)
1314                 goto err_dev_cleanup;
1315
1316         res = fuse_ctl_init();
1317         if (res)
1318                 goto err_sysfs_cleanup;
1319
1320         sanitize_global_limit(&max_user_bgreq);
1321         sanitize_global_limit(&max_user_congthresh);
1322
1323         return 0;
1324
1325  err_sysfs_cleanup:
1326         fuse_sysfs_cleanup();
1327  err_dev_cleanup:
1328         fuse_dev_cleanup();
1329  err_fs_cleanup:
1330         fuse_fs_cleanup();
1331  err:
1332         return res;
1333 }
1334
1335 static void __exit fuse_exit(void)
1336 {
1337         printk(KERN_DEBUG "fuse exit\n");
1338
1339         fuse_ctl_cleanup();
1340         fuse_sysfs_cleanup();
1341         fuse_fs_cleanup();
1342         fuse_dev_cleanup();
1343 }
1344
1345 module_init(fuse_init);
1346 module_exit(fuse_exit);