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         mutex_init(&fi->mutex);
 101         fi->forget = fuse_alloc_forget();
 102         if (!fi->forget) {
 103                 kmem_cache_free(fuse_inode_cachep, inode);
 104                 return NULL;
 105         }
 106
 107         return inode;
 108 }
 109
 110 static void fuse_i_callback(struct rcu_head *head)
 111 {
 112         struct inode *inode = container_of(head, struct inode, i_rcu);
 113         kmem_cache_free(fuse_inode_cachep, inode);
 114 }
 115
 116 static void fuse_destroy_inode(struct inode *inode)
 117 {
 118         struct fuse_inode *fi = get_fuse_inode(inode);
 119         BUG_ON(!list_empty(&fi->write_files));
 120         BUG_ON(!list_empty(&fi->queued_writes));
 121         mutex_destroy(&fi->mutex);
 122         kfree(fi->forget);
 123         call_rcu(&inode->i_rcu, fuse_i_callback);
 124 }
 125
 126 static void fuse_evict_inode(struct inode *inode)
 127 {
 128         truncate_inode_pages_final(&inode->i_data);
 129         clear_inode(inode);
 130         if (inode->i_sb->s_flags & MS_ACTIVE) {
 131                 struct fuse_conn *fc = get_fuse_conn(inode);
 132                 struct fuse_inode *fi = get_fuse_inode(inode);
 133                 fuse_queue_forget(fc, fi->forget, fi->nodeid, fi->nlookup);
 134                 fi->forget = NULL;
 135         }
 136 }
 137
 138 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 139 {
 140         sync_filesystem(sb);
 141         if (*flags & MS_MANDLOCK)
 142                 return -EINVAL;
 143
 144         return 0;
 145 }
 146
 147 /*
 148  * ino_t is 32-bits on 32-bit arch. We have to squash the 64-bit value down
 149  * so that it will fit.
 150  */
 151 static ino_t fuse_squash_ino(u64 ino64)
 152 {
 153         ino_t ino = (ino_t) ino64;
 154         if (sizeof(ino_t) < sizeof(u64))
 155                 ino ^= ino64 >> (sizeof(u64) - sizeof(ino_t)) * 8;
 156         return ino;
 157 }
 158
 159 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 160                                    u64 attr_valid)
 161 {
 162         struct fuse_conn *fc = get_fuse_conn(inode);
 163         struct fuse_inode *fi = get_fuse_inode(inode);
 164
 165         fi->attr_version = ++fc->attr_version;
 166         fi->i_time = attr_valid;
 167
 168         inode->i_ino     = fuse_squash_ino(attr->ino);
 169         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 170         set_nlink(inode, attr->nlink);
 171         inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
 172         inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
 173         inode->i_blocks  = attr->blocks;
 174         inode->i_atime.tv_sec   = attr->atime;
 175         inode->i_atime.tv_nsec  = attr->atimensec;
 176         /* mtime from server may be stale due to local buffered write */
 177         if (!fc->writeback_cache || !S_ISREG(inode->i_mode)) {
 178                 inode->i_mtime.tv_sec   = attr->mtime;
 179                 inode->i_mtime.tv_nsec  = attr->mtimensec;
 180                 inode->i_ctime.tv_sec   = attr->ctime;
 181                 inode->i_ctime.tv_nsec  = attr->ctimensec;
 182         }
 183
 184         if (attr->blksize != 0)
 185                 inode->i_blkbits = ilog2(attr->blksize);
 186         else
 187                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
 188
 189         /*
 190          * Don't set the sticky bit in i_mode, unless we want the VFS
 191          * to check permissions.  This prevents failures due to the
 192          * check in may_delete().
 193          */
 194         fi->orig_i_mode = inode->i_mode;
 195         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
 196                 inode->i_mode &= ~S_ISVTX;
 197
 198         fi->orig_ino = attr->ino;
 199 }
 200
 201 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 202                             u64 attr_valid, u64 attr_version)
 203 {
 204         struct fuse_conn *fc = get_fuse_conn(inode);
 205         struct fuse_inode *fi = get_fuse_inode(inode);
 206         bool is_wb = fc->writeback_cache;
 207         loff_t oldsize;
 208         struct timespec old_mtime;
 209
 210         spin_lock(&fc->lock);
 211         if ((attr_version != 0 && fi->attr_version > attr_version) ||
 212             test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
 213                 spin_unlock(&fc->lock);
 214                 return;
 215         }
 216
 217         old_mtime = inode->i_mtime;
 218         fuse_change_attributes_common(inode, attr, attr_valid);
 219
 220         oldsize = inode->i_size;
 221         /*
 222          * In case of writeback_cache enabled, the cached writes beyond EOF
 223          * extend local i_size without keeping userspace server in sync. So,
 224          * attr->size coming from server can be stale. We cannot trust it.
 225          */
 226         if (!is_wb || !S_ISREG(inode->i_mode))
 227                 i_size_write(inode, attr->size);
 228         spin_unlock(&fc->lock);
 229
 230         if (!is_wb && S_ISREG(inode->i_mode)) {
 231                 bool inval = false;
 232
 233                 if (oldsize != attr->size) {
 234                         truncate_pagecache(inode, attr->size);
 235                         inval = true;
 236                 } else if (fc->auto_inval_data) {
 237                         struct timespec new_mtime = {
 238                                 .tv_sec = attr->mtime,
 239                                 .tv_nsec = attr->mtimensec,
 240                         };
 241
 242                         /*
 243                          * Auto inval mode also checks and invalidates if mtime
 244                          * has changed.
 245                          */
 246                         if (!timespec_equal(&old_mtime, &new_mtime))
 247                                 inval = true;
 248                 }
 249
 250                 if (inval)
 251                         invalidate_inode_pages2(inode->i_mapping);
 252         }
 253 }
 254
 255 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 256 {
 257         inode->i_mode = attr->mode & S_IFMT;
 258         inode->i_size = attr->size;
 259         inode->i_mtime.tv_sec  = attr->mtime;
 260         inode->i_mtime.tv_nsec = attr->mtimensec;
 261         inode->i_ctime.tv_sec  = attr->ctime;
 262         inode->i_ctime.tv_nsec = attr->ctimensec;
 263         if (S_ISREG(inode->i_mode)) {
 264                 fuse_init_common(inode);
 265                 fuse_init_file_inode(inode);
 266         } else if (S_ISDIR(inode->i_mode))
 267                 fuse_init_dir(inode);
 268         else if (S_ISLNK(inode->i_mode))
 269                 fuse_init_symlink(inode);
 270         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 271                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 272                 fuse_init_common(inode);
 273                 init_special_inode(inode, inode->i_mode,
 274                                    new_decode_dev(attr->rdev));
 275         } else
 276                 BUG();
 277 }
 278
 279 int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 280 {
 281         u64 nodeid = *(u64 *) _nodeidp;
 282         if (get_node_id(inode) == nodeid)
 283                 return 1;
 284         else
 285                 return 0;
 286 }
 287
 288 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 289 {
 290         u64 nodeid = *(u64 *) _nodeidp;
 291         get_fuse_inode(inode)->nodeid = nodeid;
 292         return 0;
 293 }
 294
 295 struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 296                         int generation, struct fuse_attr *attr,
 297                         u64 attr_valid, u64 attr_version)
 298 {
 299         struct inode *inode;
 300         struct fuse_inode *fi;
 301         struct fuse_conn *fc = get_fuse_conn_super(sb);
 302
 303  retry:
 304         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 305         if (!inode)
 306                 return NULL;
 307
 308         if ((inode->i_state & I_NEW)) {
 309                 inode->i_flags |= S_NOATIME;
 310                 if (!fc->writeback_cache || !S_ISREG(attr->mode))
 311                         inode->i_flags |= S_NOCMTIME;
 312                 inode->i_generation = generation;
 313                 fuse_init_inode(inode, attr);
 314                 unlock_new_inode(inode);
 315         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 316                 /* Inode has changed type, any I/O on the old should fail */
 317                 make_bad_inode(inode);
 318                 iput(inode);
 319                 goto retry;
 320         }
 321
 322         fi = get_fuse_inode(inode);
 323         spin_lock(&fc->lock);
 324         fi->nlookup++;
 325         spin_unlock(&fc->lock);
 326         fuse_change_attributes(inode, attr, attr_valid, attr_version);
 327
 328         return inode;
 329 }
 330
 331 int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
 332                              loff_t offset, loff_t len)
 333 {
 334         struct inode *inode;
 335         pgoff_t pg_start;
 336         pgoff_t pg_end;
 337
 338         inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
 339         if (!inode)
 340                 return -ENOENT;
 341
 342         fuse_invalidate_attr(inode);
 343         if (offset >= 0) {
 344                 pg_start = offset >> PAGE_SHIFT;
 345                 if (len <= 0)
 346                         pg_end = -1;
 347                 else
 348                         pg_end = (offset + len - 1) >> PAGE_SHIFT;
 349                 invalidate_inode_pages2_range(inode->i_mapping,
 350                                               pg_start, pg_end);
 351         }
 352         iput(inode);
 353         return 0;
 354 }
 355
 356 void fuse_lock_inode(struct inode *inode)
 357 {
 358         if (!get_fuse_conn(inode)->parallel_dirops)
 359                 mutex_lock(&get_fuse_inode(inode)->mutex);
 360 }
 361
 362 void fuse_unlock_inode(struct inode *inode)
 363 {
 364         if (!get_fuse_conn(inode)->parallel_dirops)
 365                 mutex_unlock(&get_fuse_inode(inode)->mutex);
 366 }
 367
 368 static void fuse_umount_begin(struct super_block *sb)
 369 {
 370         fuse_abort_conn(get_fuse_conn_super(sb));
 371 }
 372
 373 static void fuse_send_destroy(struct fuse_conn *fc)
 374 {
 375         struct fuse_req *req = fc->destroy_req;
 376         if (req && fc->conn_init) {
 377                 fc->destroy_req = NULL;
 378                 req->in.h.opcode = FUSE_DESTROY;
 379                 __set_bit(FR_FORCE, &req->flags);
 380                 __clear_bit(FR_BACKGROUND, &req->flags);
 381                 fuse_request_send(fc, req);
 382                 fuse_put_request(fc, req);
 383         }
 384 }
 385
 386 static void fuse_bdi_destroy(struct fuse_conn *fc)
 387 {
 388         if (fc->bdi_initialized)
 389                 bdi_destroy(&fc->bdi);
 390 }
 391
 392 static void fuse_put_super(struct super_block *sb)
 393 {
 394         struct fuse_conn *fc = get_fuse_conn_super(sb);
 395
 396         fuse_send_destroy(fc);
 397
 398         fuse_abort_conn(fc);
 399         mutex_lock(&fuse_mutex);
 400         list_del(&fc->entry);
 401         fuse_ctl_remove_conn(fc);
 402         mutex_unlock(&fuse_mutex);
 403         fuse_bdi_destroy(fc);
 404
 405         fuse_conn_put(fc);
 406 }
 407
 408 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 409 {
 410         stbuf->f_type    = FUSE_SUPER_MAGIC;
 411         stbuf->f_bsize   = attr->bsize;
 412         stbuf->f_frsize  = attr->frsize;
 413         stbuf->f_blocks  = attr->blocks;
 414         stbuf->f_bfree   = attr->bfree;
 415         stbuf->f_bavail  = attr->bavail;
 416         stbuf->f_files   = attr->files;
 417         stbuf->f_ffree   = attr->ffree;
 418         stbuf->f_namelen = attr->namelen;
 419         /* fsid is left zero */
 420 }
 421
 422 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 423 {
 424         struct super_block *sb = dentry->d_sb;
 425         struct fuse_conn *fc = get_fuse_conn_super(sb);
 426         FUSE_ARGS(args);
 427         struct fuse_statfs_out outarg;
 428         int err;
 429
 430         if (!fuse_allow_current_process(fc)) {
 431                 buf->f_type = FUSE_SUPER_MAGIC;
 432                 return 0;
 433         }
 434
 435         memset(&outarg, 0, sizeof(outarg));
 436         args.in.numargs = 0;
 437         args.in.h.opcode = FUSE_STATFS;
 438         args.in.h.nodeid = get_node_id(d_inode(dentry));
 439         args.out.numargs = 1;
 440         args.out.args[0].size = sizeof(outarg);
 441         args.out.args[0].value = &outarg;
 442         err = fuse_simple_request(fc, &args);
 443         if (!err)
 444                 convert_fuse_statfs(buf, &outarg.st);
 445         return err;
 446 }
 447
 448 enum {
 449         OPT_FD,
 450         OPT_ROOTMODE,
 451         OPT_USER_ID,
 452         OPT_GROUP_ID,
 453         OPT_DEFAULT_PERMISSIONS,
 454         OPT_ALLOW_OTHER,
 455         OPT_MAX_READ,
 456         OPT_BLKSIZE,
 457         OPT_ERR
 458 };
 459
 460 static const match_table_t tokens = {
 461         {OPT_FD,                        "fd=%u"},
 462         {OPT_ROOTMODE,                  "rootmode=%o"},
 463         {OPT_USER_ID,                   "user_id=%u"},
 464         {OPT_GROUP_ID,                  "group_id=%u"},
 465         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 466         {OPT_ALLOW_OTHER,               "allow_other"},
 467         {OPT_MAX_READ,                  "max_read=%u"},
 468         {OPT_BLKSIZE,                   "blksize=%u"},
 469         {OPT_ERR,                       NULL}
 470 };
 471
 472 static int fuse_match_uint(substring_t *s, unsigned int *res)
 473 {
 474         int err = -ENOMEM;
 475         char *buf = match_strdup(s);
 476         if (buf) {
 477                 err = kstrtouint(buf, 10, res);
 478                 kfree(buf);
 479         }
 480         return err;
 481 }
 482
 483 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 484 {
 485         char *p;
 486         memset(d, 0, sizeof(struct fuse_mount_data));
 487         d->max_read = ~0;
 488         d->blksize = FUSE_DEFAULT_BLKSIZE;
 489
 490         while ((p = strsep(&opt, ",")) != NULL) {
 491                 int token;
 492                 int value;
 493                 unsigned uv;
 494                 substring_t args[MAX_OPT_ARGS];
 495                 if (!*p)
 496                         continue;
 497
 498                 token = match_token(p, tokens, args);
 499                 switch (token) {
 500                 case OPT_FD:
 501                         if (match_int(&args[0], &value))
 502                                 return 0;
 503                         d->fd = value;
 504                         d->fd_present = 1;
 505                         break;
 506
 507                 case OPT_ROOTMODE:
 508                         if (match_octal(&args[0], &value))
 509                                 return 0;
 510                         if (!fuse_valid_type(value))
 511                                 return 0;
 512                         d->rootmode = value;
 513                         d->rootmode_present = 1;
 514                         break;
 515
 516                 case OPT_USER_ID:
 517                         if (fuse_match_uint(&args[0], &uv))
 518                                 return 0;
 519                         d->user_id = make_kuid(current_user_ns(), uv);
 520                         if (!uid_valid(d->user_id))
 521                                 return 0;
 522                         d->user_id_present = 1;
 523                         break;
 524
 525                 case OPT_GROUP_ID:
 526                         if (fuse_match_uint(&args[0], &uv))
 527                                 return 0;
 528                         d->group_id = make_kgid(current_user_ns(), uv);
 529                         if (!gid_valid(d->group_id))
 530                                 return 0;
 531                         d->group_id_present = 1;
 532                         break;
 533
 534                 case OPT_DEFAULT_PERMISSIONS:
 535                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 536                         break;
 537
 538                 case OPT_ALLOW_OTHER:
 539                         d->flags |= FUSE_ALLOW_OTHER;
 540                         break;
 541
 542                 case OPT_MAX_READ:
 543                         if (match_int(&args[0], &value))
 544                                 return 0;
 545                         d->max_read = value;
 546                         break;
 547
 548                 case OPT_BLKSIZE:
 549                         if (!is_bdev || match_int(&args[0], &value))
 550                                 return 0;
 551                         d->blksize = value;
 552                         break;
 553
 554                 default:
 555                         return 0;
 556                 }
 557         }
 558
 559         if (!d->fd_present || !d->rootmode_present ||
 560             !d->user_id_present || !d->group_id_present)
 561                 return 0;
 562
 563         return 1;
 564 }
 565
 566 static int fuse_show_options(struct seq_file *m, struct dentry *root)
 567 {
 568         struct super_block *sb = root->d_sb;
 569         struct fuse_conn *fc = get_fuse_conn_super(sb);
 570
 571         seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
 572         seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
 573         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 574                 seq_puts(m, ",default_permissions");
 575         if (fc->flags & FUSE_ALLOW_OTHER)
 576                 seq_puts(m, ",allow_other");
 577         if (fc->max_read != ~0)
 578                 seq_printf(m, ",max_read=%u", fc->max_read);
 579         if (sb->s_bdev && sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 580                 seq_printf(m, ",blksize=%lu", sb->s_blocksize);
 581         return 0;
 582 }
 583
 584 static void fuse_iqueue_init(struct fuse_iqueue *fiq)
 585 {
 586         memset(fiq, 0, sizeof(struct fuse_iqueue));
 587         init_waitqueue_head(&fiq->waitq);
 588         INIT_LIST_HEAD(&fiq->pending);
 589         INIT_LIST_HEAD(&fiq->interrupts);
 590         fiq->forget_list_tail = &fiq->forget_list_head;
 591         fiq->connected = 1;
 592 }
 593
 594 static void fuse_pqueue_init(struct fuse_pqueue *fpq)
 595 {
 596         memset(fpq, 0, sizeof(struct fuse_pqueue));
 597         spin_lock_init(&fpq->lock);
 598         INIT_LIST_HEAD(&fpq->processing);
 599         INIT_LIST_HEAD(&fpq->io);
 600         fpq->connected = 1;
 601 }
 602
 603 void fuse_conn_init(struct fuse_conn *fc)
 604 {
 605         memset(fc, 0, sizeof(*fc));
 606         spin_lock_init(&fc->lock);
 607         init_rwsem(&fc->killsb);
 608         atomic_set(&fc->count, 1);
 609         atomic_set(&fc->dev_count, 1);
 610         init_waitqueue_head(&fc->blocked_waitq);
 611         init_waitqueue_head(&fc->reserved_req_waitq);
 612         fuse_iqueue_init(&fc->iq);
 613         INIT_LIST_HEAD(&fc->bg_queue);
 614         INIT_LIST_HEAD(&fc->entry);
 615         INIT_LIST_HEAD(&fc->devices);
 616         atomic_set(&fc->num_waiting, 0);
 617         fc->max_background = FUSE_DEFAULT_MAX_BACKGROUND;
 618         fc->congestion_threshold = FUSE_DEFAULT_CONGESTION_THRESHOLD;
 619         fc->khctr = 0;
 620         fc->polled_files = RB_ROOT;
 621         fc->blocked = 0;
 622         fc->initialized = 0;
 623         fc->connected = 1;
 624         fc->attr_version = 1;
 625         get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 626 }
 627 EXPORT_SYMBOL_GPL(fuse_conn_init);
 628
 629 void fuse_conn_put(struct fuse_conn *fc)
 630 {
 631         if (atomic_dec_and_test(&fc->count)) {
 632                 if (fc->destroy_req)
 633                         fuse_request_free(fc->destroy_req);
 634                 fc->release(fc);
 635         }
 636 }
 637 EXPORT_SYMBOL_GPL(fuse_conn_put);
 638
 639 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 640 {
 641         atomic_inc(&fc->count);
 642         return fc;
 643 }
 644 EXPORT_SYMBOL_GPL(fuse_conn_get);
 645
 646 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 647 {
 648         struct fuse_attr attr;
 649         memset(&attr, 0, sizeof(attr));
 650
 651         attr.mode = mode;
 652         attr.ino = FUSE_ROOT_ID;
 653         attr.nlink = 1;
 654         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 655 }
 656
 657 struct fuse_inode_handle {
 658         u64 nodeid;
 659         u32 generation;
 660 };
 661
 662 static struct dentry *fuse_get_dentry(struct super_block *sb,
 663                                       struct fuse_inode_handle *handle)
 664 {
 665         struct fuse_conn *fc = get_fuse_conn_super(sb);
 666         struct inode *inode;
 667         struct dentry *entry;
 668         int err = -ESTALE;
 669
 670         if (handle->nodeid == 0)
 671                 goto out_err;
 672
 673         inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid);
 674         if (!inode) {
 675                 struct fuse_entry_out outarg;
 676                 struct qstr name;
 677
 678                 if (!fc->export_support)
 679                         goto out_err;
 680
 681                 name.len = 1;
 682                 name.name = ".";
 683                 err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg,
 684                                        &inode);
 685                 if (err && err != -ENOENT)
 686                         goto out_err;
 687                 if (err || !inode) {
 688                         err = -ESTALE;
 689                         goto out_err;
 690                 }
 691                 err = -EIO;
 692                 if (get_node_id(inode) != handle->nodeid)
 693                         goto out_iput;
 694         }
 695         err = -ESTALE;
 696         if (inode->i_generation != handle->generation)
 697                 goto out_iput;
 698
 699         entry = d_obtain_alias(inode);
 700         if (!IS_ERR(entry) && get_node_id(inode) != FUSE_ROOT_ID)
 701                 fuse_invalidate_entry_cache(entry);
 702
 703         return entry;
 704
 705  out_iput:
 706         iput(inode);
 707  out_err:
 708         return ERR_PTR(err);
 709 }
 710
 711 static int fuse_encode_fh(struct inode *inode, u32 *fh, int *max_len,
 712                            struct inode *parent)
 713 {
 714         int len = parent ? 6 : 3;
 715         u64 nodeid;
 716         u32 generation;
 717
 718         if (*max_len < len) {
 719                 *max_len = len;
 720                 return  FILEID_INVALID;
 721         }
 722
 723         nodeid = get_fuse_inode(inode)->nodeid;
 724         generation = inode->i_generation;
 725
 726         fh[0] = (u32)(nodeid >> 32);
 727         fh[1] = (u32)(nodeid & 0xffffffff);
 728         fh[2] = generation;
 729
 730         if (parent) {
 731                 nodeid = get_fuse_inode(parent)->nodeid;
 732                 generation = parent->i_generation;
 733
 734                 fh[3] = (u32)(nodeid >> 32);
 735                 fh[4] = (u32)(nodeid & 0xffffffff);
 736                 fh[5] = generation;
 737         }
 738
 739         *max_len = len;
 740         return parent ? 0x82 : 0x81;
 741 }
 742
 743 static struct dentry *fuse_fh_to_dentry(struct super_block *sb,
 744                 struct fid *fid, int fh_len, int fh_type)
 745 {
 746         struct fuse_inode_handle handle;
 747
 748         if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3)
 749                 return NULL;
 750
 751         handle.nodeid = (u64) fid->raw[0] << 32;
 752         handle.nodeid |= (u64) fid->raw[1];
 753         handle.generation = fid->raw[2];
 754         return fuse_get_dentry(sb, &handle);
 755 }
 756
 757 static struct dentry *fuse_fh_to_parent(struct super_block *sb,
 758                 struct fid *fid, int fh_len, int fh_type)
 759 {
 760         struct fuse_inode_handle parent;
 761
 762         if (fh_type != 0x82 || fh_len < 6)
 763                 return NULL;
 764
 765         parent.nodeid = (u64) fid->raw[3] << 32;
 766         parent.nodeid |= (u64) fid->raw[4];
 767         parent.generation = fid->raw[5];
 768         return fuse_get_dentry(sb, &parent);
 769 }
 770
 771 static struct dentry *fuse_get_parent(struct dentry *child)
 772 {
 773         struct inode *child_inode = d_inode(child);
 774         struct fuse_conn *fc = get_fuse_conn(child_inode);
 775         struct inode *inode;
 776         struct dentry *parent;
 777         struct fuse_entry_out outarg;
 778         struct qstr name;
 779         int err;
 780
 781         if (!fc->export_support)
 782                 return ERR_PTR(-ESTALE);
 783
 784         name.len = 2;
 785         name.name = "..";
 786         err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode),
 787                                &name, &outarg, &inode);
 788         if (err) {
 789                 if (err == -ENOENT)
 790                         return ERR_PTR(-ESTALE);
 791                 return ERR_PTR(err);
 792         }
 793
 794         parent = d_obtain_alias(inode);
 795         if (!IS_ERR(parent) && get_node_id(inode) != FUSE_ROOT_ID)
 796                 fuse_invalidate_entry_cache(parent);
 797
 798         return parent;
 799 }
 800
 801 static const struct export_operations fuse_export_operations = {
 802         .fh_to_dentry   = fuse_fh_to_dentry,
 803         .fh_to_parent   = fuse_fh_to_parent,
 804         .encode_fh      = fuse_encode_fh,
 805         .get_parent     = fuse_get_parent,
 806 };
 807
 808 static const struct super_operations fuse_super_operations = {
 809         .alloc_inode    = fuse_alloc_inode,
 810         .destroy_inode  = fuse_destroy_inode,
 811         .evict_inode    = fuse_evict_inode,
 812         .write_inode    = fuse_write_inode,
 813         .drop_inode     = generic_delete_inode,
 814         .remount_fs     = fuse_remount_fs,
 815         .put_super      = fuse_put_super,
 816         .umount_begin   = fuse_umount_begin,
 817         .statfs         = fuse_statfs,
 818         .show_options   = fuse_show_options,
 819 };
 820
 821 static void sanitize_global_limit(unsigned *limit)
 822 {
 823         if (*limit == 0)
 824                 *limit = ((totalram_pages << PAGE_SHIFT) >> 13) /
 825                          sizeof(struct fuse_req);
 826
 827         if (*limit >= 1 << 16)
 828                 *limit = (1 << 16) - 1;
 829 }
 830
 831 static int set_global_limit(const char *val, struct kernel_param *kp)
 832 {
 833         int rv;
 834
 835         rv = param_set_uint(val, kp);
 836         if (rv)
 837                 return rv;
 838
 839         sanitize_global_limit((unsigned *)kp->arg);
 840
 841         return 0;
 842 }
 843
 844 static void process_init_limits(struct fuse_conn *fc, struct fuse_init_out *arg)
 845 {
 846         int cap_sys_admin = capable(CAP_SYS_ADMIN);
 847
 848         if (arg->minor < 13)
 849                 return;
 850
 851         sanitize_global_limit(&max_user_bgreq);
 852         sanitize_global_limit(&max_user_congthresh);
 853
 854         if (arg->max_background) {
 855                 fc->max_background = arg->max_background;
 856
 857                 if (!cap_sys_admin && fc->max_background > max_user_bgreq)
 858                         fc->max_background = max_user_bgreq;
 859         }
 860         if (arg->congestion_threshold) {
 861                 fc->congestion_threshold = arg->congestion_threshold;
 862
 863                 if (!cap_sys_admin &&
 864                     fc->congestion_threshold > max_user_congthresh)
 865                         fc->congestion_threshold = max_user_congthresh;
 866         }
 867 }
 868
 869 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 870 {
 871         struct fuse_init_out *arg = &req->misc.init_out;
 872
 873         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 874                 fc->conn_error = 1;
 875         else {
 876                 unsigned long ra_pages;
 877
 878                 process_init_limits(fc, arg);
 879
 880                 if (arg->minor >= 6) {
 881                         ra_pages = arg->max_readahead / PAGE_SIZE;
 882                         if (arg->flags & FUSE_ASYNC_READ)
 883                                 fc->async_read = 1;
 884                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 885                                 fc->no_lock = 1;
 886                         if (arg->minor >= 17) {
 887                                 if (!(arg->flags & FUSE_FLOCK_LOCKS))
 888                                         fc->no_flock = 1;
 889                         } else {
 890                                 if (!(arg->flags & FUSE_POSIX_LOCKS))
 891                                         fc->no_flock = 1;
 892                         }
 893                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 894                                 fc->atomic_o_trunc = 1;
 895                         if (arg->minor >= 9) {
 896                                 /* LOOKUP has dependency on proto version */
 897                                 if (arg->flags & FUSE_EXPORT_SUPPORT)
 898                                         fc->export_support = 1;
 899                         }
 900                         if (arg->flags & FUSE_BIG_WRITES)
 901                                 fc->big_writes = 1;
 902                         if (arg->flags & FUSE_DONT_MASK)
 903                                 fc->dont_mask = 1;
 904                         if (arg->flags & FUSE_AUTO_INVAL_DATA)
 905                                 fc->auto_inval_data = 1;
 906                         if (arg->flags & FUSE_DO_READDIRPLUS) {
 907                                 fc->do_readdirplus = 1;
 908                                 if (arg->flags & FUSE_READDIRPLUS_AUTO)
 909                                         fc->readdirplus_auto = 1;
 910                         }
 911                         if (arg->flags & FUSE_ASYNC_DIO)
 912                                 fc->async_dio = 1;
 913                         if (arg->flags & FUSE_WRITEBACK_CACHE)
 914                                 fc->writeback_cache = 1;
 915                         if (arg->flags & FUSE_PARALLEL_DIROPS)
 916                                 fc->parallel_dirops = 1;
 917                         if (arg->time_gran && arg->time_gran <= 1000000000)
 918                                 fc->sb->s_time_gran = arg->time_gran;
 919                 } else {
 920                         ra_pages = fc->max_read / PAGE_SIZE;
 921                         fc->no_lock = 1;
 922                         fc->no_flock = 1;
 923                 }
 924
 925                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 926                 fc->minor = arg->minor;
 927                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 928                 fc->max_write = max_t(unsigned, 4096, fc->max_write);
 929                 fc->conn_init = 1;
 930         }
 931         fuse_set_initialized(fc);
 932         wake_up_all(&fc->blocked_waitq);
 933 }
 934
 935 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 936 {
 937         struct fuse_init_in *arg = &req->misc.init_in;
 938
 939         arg->major = FUSE_KERNEL_VERSION;
 940         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 941         arg->max_readahead = fc->bdi.ra_pages * PAGE_SIZE;
 942         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC |
 943                 FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES | FUSE_DONT_MASK |
 944                 FUSE_SPLICE_WRITE | FUSE_SPLICE_MOVE | FUSE_SPLICE_READ |
 945                 FUSE_FLOCK_LOCKS | FUSE_HAS_IOCTL_DIR | FUSE_AUTO_INVAL_DATA |
 946                 FUSE_DO_READDIRPLUS | FUSE_READDIRPLUS_AUTO | FUSE_ASYNC_DIO |
 947                 FUSE_WRITEBACK_CACHE | FUSE_NO_OPEN_SUPPORT |
 948                 FUSE_PARALLEL_DIROPS;
 949         req->in.h.opcode = FUSE_INIT;
 950         req->in.numargs = 1;
 951         req->in.args[0].size = sizeof(*arg);
 952         req->in.args[0].value = arg;
 953         req->out.numargs = 1;
 954         /* Variable length argument used for backward compatibility
 955            with interface version < 7.5.  Rest of init_out is zeroed
 956            by do_get_request(), so a short reply is not a problem */
 957         req->out.argvar = 1;
 958         req->out.args[0].size = sizeof(struct fuse_init_out);
 959         req->out.args[0].value = &req->misc.init_out;
 960         req->end = process_init_reply;
 961         fuse_request_send_background(fc, req);
 962 }
 963
 964 static void fuse_free_conn(struct fuse_conn *fc)
 965 {
 966         WARN_ON(!list_empty(&fc->devices));
 967         kfree_rcu(fc, rcu);
 968 }
 969
 970 static int fuse_bdi_init(struct fuse_conn *fc, struct super_block *sb)
 971 {
 972         int err;
 973
 974         fc->bdi.name = "fuse";
 975         fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_SIZE;
 976         /* fuse does it's own writeback accounting */
 977         fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB | BDI_CAP_STRICTLIMIT;
 978
 979         err = bdi_init(&fc->bdi);
 980         if (err)
 981                 return err;
 982
 983         fc->bdi_initialized = 1;
 984
 985         if (sb->s_bdev) {
 986                 err =  bdi_register(&fc->bdi, NULL, "%u:%u-fuseblk",
 987                                     MAJOR(fc->dev), MINOR(fc->dev));
 988         } else {
 989                 err = bdi_register_dev(&fc->bdi, fc->dev);
 990         }
 991
 992         if (err)
 993                 return err;
 994
 995         /*
 996          * For a single fuse filesystem use max 1% of dirty +
 997          * writeback threshold.
 998          *
 999          * This gives about 1M of write buffer for memory maps on a
1000          * machine with 1G and 10% dirty_ratio, which should be more
1001          * than enough.
1002          *
1003          * Privileged users can raise it by writing to
1004          *
1005          *    /sys/class/bdi/<bdi>/max_ratio
1006          */
1007         bdi_set_max_ratio(&fc->bdi, 1);
1008
1009         return 0;
1010 }
1011
1012 struct fuse_dev *fuse_dev_alloc(struct fuse_conn *fc)
1013 {
1014         struct fuse_dev *fud;
1015
1016         fud = kzalloc(sizeof(struct fuse_dev), GFP_KERNEL);
1017         if (fud) {
1018                 fud->fc = fuse_conn_get(fc);
1019                 fuse_pqueue_init(&fud->pq);
1020
1021                 spin_lock(&fc->lock);
1022                 list_add_tail(&fud->entry, &fc->devices);
1023                 spin_unlock(&fc->lock);
1024         }
1025
1026         return fud;
1027 }
1028 EXPORT_SYMBOL_GPL(fuse_dev_alloc);
1029
1030 void fuse_dev_free(struct fuse_dev *fud)
1031 {
1032         struct fuse_conn *fc = fud->fc;
1033
1034         if (fc) {
1035                 spin_lock(&fc->lock);
1036                 list_del(&fud->entry);
1037                 spin_unlock(&fc->lock);
1038
1039                 fuse_conn_put(fc);
1040         }
1041         kfree(fud);
1042 }
1043 EXPORT_SYMBOL_GPL(fuse_dev_free);
1044
1045 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
1046 {
1047         struct fuse_dev *fud;
1048         struct fuse_conn *fc;
1049         struct inode *root;
1050         struct fuse_mount_data d;
1051         struct file *file;
1052         struct dentry *root_dentry;
1053         struct fuse_req *init_req;
1054         int err;
1055         int is_bdev = sb->s_bdev != NULL;
1056
1057         err = -EINVAL;
1058         if (sb->s_flags & MS_MANDLOCK)
1059                 goto err;
1060
1061         sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
1062
1063         if (!parse_fuse_opt(data, &d, is_bdev))
1064                 goto err;
1065
1066         if (is_bdev) {
1067 #ifdef CONFIG_BLOCK
1068                 err = -EINVAL;
1069                 if (!sb_set_blocksize(sb, d.blksize))
1070                         goto err;
1071 #endif
1072         } else {
1073                 sb->s_blocksize = PAGE_SIZE;
1074                 sb->s_blocksize_bits = PAGE_SHIFT;
1075         }
1076         sb->s_magic = FUSE_SUPER_MAGIC;
1077         sb->s_op = &fuse_super_operations;
1078         sb->s_maxbytes = MAX_LFS_FILESIZE;
1079         sb->s_time_gran = 1;
1080         sb->s_export_op = &fuse_export_operations;
1081
1082         file = fget(d.fd);
1083         err = -EINVAL;
1084         if (!file)
1085                 goto err;
1086
1087         if ((file->f_op != &fuse_dev_operations) ||
1088             (file->f_cred->user_ns != &init_user_ns))
1089                 goto err_fput;
1090
1091         fc = kmalloc(sizeof(*fc), GFP_KERNEL);
1092         err = -ENOMEM;
1093         if (!fc)
1094                 goto err_fput;
1095
1096         fuse_conn_init(fc);
1097         fc->release = fuse_free_conn;
1098
1099         fud = fuse_dev_alloc(fc);
1100         if (!fud)
1101                 goto err_put_conn;
1102
1103         fc->dev = sb->s_dev;
1104         fc->sb = sb;
1105         err = fuse_bdi_init(fc, sb);
1106         if (err)
1107                 goto err_dev_free;
1108
1109         sb->s_bdi = &fc->bdi;
1110
1111         /* Handle umasking inside the fuse code */
1112         if (sb->s_flags & MS_POSIXACL)
1113                 fc->dont_mask = 1;
1114         sb->s_flags |= MS_POSIXACL;
1115
1116         fc->flags = d.flags;
1117         fc->user_id = d.user_id;
1118         fc->group_id = d.group_id;
1119         fc->max_read = max_t(unsigned, 4096, d.max_read);
1120
1121         /* Used by get_root_inode() */
1122         sb->s_fs_info = fc;
1123
1124         err = -ENOMEM;
1125         root = fuse_get_root_inode(sb, d.rootmode);
1126         root_dentry = d_make_root(root);
1127         if (!root_dentry)
1128                 goto err_dev_free;
1129         /* only now - we want root dentry with NULL ->d_op */
1130         sb->s_d_op = &fuse_dentry_operations;
1131
1132         init_req = fuse_request_alloc(0);
1133         if (!init_req)
1134                 goto err_put_root;
1135         __set_bit(FR_BACKGROUND, &init_req->flags);
1136
1137         if (is_bdev) {
1138                 fc->destroy_req = fuse_request_alloc(0);
1139                 if (!fc->destroy_req)
1140                         goto err_free_init_req;
1141         }
1142
1143         mutex_lock(&fuse_mutex);
1144         err = -EINVAL;
1145         if (file->private_data)
1146                 goto err_unlock;
1147
1148         err = fuse_ctl_add_conn(fc);
1149         if (err)
1150                 goto err_unlock;
1151
1152         list_add_tail(&fc->entry, &fuse_conn_list);
1153         sb->s_root = root_dentry;
1154         file->private_data = fud;
1155         mutex_unlock(&fuse_mutex);
1156         /*
1157          * atomic_dec_and_test() in fput() provides the necessary
1158          * memory barrier for file->private_data to be visible on all
1159          * CPUs after this
1160          */
1161         fput(file);
1162
1163         fuse_send_init(fc, init_req);
1164
1165         return 0;
1166
1167  err_unlock:
1168         mutex_unlock(&fuse_mutex);
1169  err_free_init_req:
1170         fuse_request_free(init_req);
1171  err_put_root:
1172         dput(root_dentry);
1173  err_dev_free:
1174         fuse_dev_free(fud);
1175  err_put_conn:
1176         fuse_bdi_destroy(fc);
1177         fuse_conn_put(fc);
1178  err_fput:
1179         fput(file);
1180  err:
1181         return err;
1182 }
1183
1184 static struct dentry *fuse_mount(struct file_system_type *fs_type,
1185                        int flags, const char *dev_name,
1186                        void *raw_data)
1187 {
1188         return mount_nodev(fs_type, flags, raw_data, fuse_fill_super);
1189 }
1190
1191 static void fuse_kill_sb_anon(struct super_block *sb)
1192 {
1193         struct fuse_conn *fc = get_fuse_conn_super(sb);
1194
1195         if (fc) {
1196                 down_write(&fc->killsb);
1197                 fc->sb = NULL;
1198                 up_write(&fc->killsb);
1199         }
1200
1201         kill_anon_super(sb);
1202 }
1203
1204 static struct file_system_type fuse_fs_type = {
1205         .owner          = THIS_MODULE,
1206         .name           = "fuse",
1207         .fs_flags       = FS_HAS_SUBTYPE,
1208         .mount          = fuse_mount,
1209         .kill_sb        = fuse_kill_sb_anon,
1210 };
1211 MODULE_ALIAS_FS("fuse");
1212
1213 #ifdef CONFIG_BLOCK
1214 static struct dentry *fuse_mount_blk(struct file_system_type *fs_type,
1215                            int flags, const char *dev_name,
1216                            void *raw_data)
1217 {
1218         return mount_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super);
1219 }
1220
1221 static void fuse_kill_sb_blk(struct super_block *sb)
1222 {
1223         struct fuse_conn *fc = get_fuse_conn_super(sb);
1224
1225         if (fc) {
1226                 down_write(&fc->killsb);
1227                 fc->sb = NULL;
1228                 up_write(&fc->killsb);
1229         }
1230
1231         kill_block_super(sb);
1232 }
1233
1234 static struct file_system_type fuseblk_fs_type = {
1235         .owner          = THIS_MODULE,
1236         .name           = "fuseblk",
1237         .mount          = fuse_mount_blk,
1238         .kill_sb        = fuse_kill_sb_blk,
1239         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
1240 };
1241 MODULE_ALIAS_FS("fuseblk");
1242
1243 static inline int register_fuseblk(void)
1244 {
1245         return register_filesystem(&fuseblk_fs_type);
1246 }
1247
1248 static inline void unregister_fuseblk(void)
1249 {
1250         unregister_filesystem(&fuseblk_fs_type);
1251 }
1252 #else
1253 static inline int register_fuseblk(void)
1254 {
1255         return 0;
1256 }
1257
1258 static inline void unregister_fuseblk(void)
1259 {
1260 }
1261 #endif
1262
1263 static void fuse_inode_init_once(void *foo)
1264 {
1265         struct inode *inode = foo;
1266
1267         inode_init_once(inode);
1268 }
1269
1270 static int __init fuse_fs_init(void)
1271 {
1272         int err;
1273
1274         fuse_inode_cachep = kmem_cache_create("fuse_inode",
1275                                               sizeof(struct fuse_inode), 0,
1276                                               SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
1277                                               fuse_inode_init_once);
1278         err = -ENOMEM;
1279         if (!fuse_inode_cachep)
1280                 goto out;
1281
1282         err = register_fuseblk();
1283         if (err)
1284                 goto out2;
1285
1286         err = register_filesystem(&fuse_fs_type);
1287         if (err)
1288                 goto out3;
1289
1290         return 0;
1291
1292  out3:
1293         unregister_fuseblk();
1294  out2:
1295         kmem_cache_destroy(fuse_inode_cachep);
1296  out:
1297         return err;
1298 }
1299
1300 static void fuse_fs_cleanup(void)
1301 {
1302         unregister_filesystem(&fuse_fs_type);
1303         unregister_fuseblk();
1304
1305         /*
1306          * Make sure all delayed rcu free inodes are flushed before we
1307          * destroy cache.
1308          */
1309         rcu_barrier();
1310         kmem_cache_destroy(fuse_inode_cachep);
1311 }
1312
1313 static struct kobject *fuse_kobj;
1314
1315 static int fuse_sysfs_init(void)
1316 {
1317         int err;
1318
1319         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
1320         if (!fuse_kobj) {
1321                 err = -ENOMEM;
1322                 goto out_err;
1323         }
1324
1325         err = sysfs_create_mount_point(fuse_kobj, "connections");
1326         if (err)
1327                 goto out_fuse_unregister;
1328
1329         return 0;
1330
1331  out_fuse_unregister:
1332         kobject_put(fuse_kobj);
1333  out_err:
1334         return err;
1335 }
1336
1337 static void fuse_sysfs_cleanup(void)
1338 {
1339         sysfs_remove_mount_point(fuse_kobj, "connections");
1340         kobject_put(fuse_kobj);
1341 }
1342
1343 static int __init fuse_init(void)
1344 {
1345         int res;
1346
1347         printk(KERN_INFO "fuse init (API version %i.%i)\n",
1348                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
1349
1350         INIT_LIST_HEAD(&fuse_conn_list);
1351         res = fuse_fs_init();
1352         if (res)
1353                 goto err;
1354
1355         res = fuse_dev_init();
1356         if (res)
1357                 goto err_fs_cleanup;
1358
1359         res = fuse_sysfs_init();
1360         if (res)
1361                 goto err_dev_cleanup;
1362
1363         res = fuse_ctl_init();
1364         if (res)
1365                 goto err_sysfs_cleanup;
1366
1367         sanitize_global_limit(&max_user_bgreq);
1368         sanitize_global_limit(&max_user_congthresh);
1369
1370         return 0;
1371
1372  err_sysfs_cleanup:
1373         fuse_sysfs_cleanup();
1374  err_dev_cleanup:
1375         fuse_dev_cleanup();
1376  err_fs_cleanup:
1377         fuse_fs_cleanup();
1378  err:
1379         return res;
1380 }
1381
1382 static void __exit fuse_exit(void)
1383 {
1384         printk(KERN_DEBUG "fuse exit\n");
1385
1386         fuse_ctl_cleanup();
1387         fuse_sysfs_cleanup();
1388         fuse_fs_cleanup();
1389         fuse_dev_cleanup();
1390 }
1391
1392 module_init(fuse_init);
1393 module_exit(fuse_exit);