fs/fuse/inode.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2006  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/parser.h>
  18 #include <linux/statfs.h>
  19 #include <linux/random.h>
  20
  21 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
  22 MODULE_DESCRIPTION("Filesystem in Userspace");
  23 MODULE_LICENSE("GPL");
  24
  25 static struct kmem_cache *fuse_inode_cachep;
  26 struct list_head fuse_conn_list;
  27 DEFINE_MUTEX(fuse_mutex);
  28
  29 #define FUSE_SUPER_MAGIC 0x65735546
  30
  31 struct fuse_mount_data {
  32         int fd;
  33         unsigned rootmode;
  34         unsigned user_id;
  35         unsigned group_id;
  36         unsigned fd_present : 1;
  37         unsigned rootmode_present : 1;
  38         unsigned user_id_present : 1;
  39         unsigned group_id_present : 1;
  40         unsigned flags;
  41         unsigned max_read;
  42 };
  43
  44 static struct inode *fuse_alloc_inode(struct super_block *sb)
  45 {
  46         struct inode *inode;
  47         struct fuse_inode *fi;
  48
  49         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
  50         if (!inode)
  51                 return NULL;
  52
  53         fi = get_fuse_inode(inode);
  54         fi->i_time = 0;
  55         fi->nodeid = 0;
  56         fi->nlookup = 0;
  57         fi->forget_req = fuse_request_alloc();
  58         if (!fi->forget_req) {
  59                 kmem_cache_free(fuse_inode_cachep, inode);
  60                 return NULL;
  61         }
  62
  63         return inode;
  64 }
  65
  66 static void fuse_destroy_inode(struct inode *inode)
  67 {
  68         struct fuse_inode *fi = get_fuse_inode(inode);
  69         if (fi->forget_req)
  70                 fuse_request_free(fi->forget_req);
  71         kmem_cache_free(fuse_inode_cachep, inode);
  72 }
  73
  74 static void fuse_read_inode(struct inode *inode)
  75 {
  76         /* No op */
  77 }
  78
  79 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
  80                       unsigned long nodeid, u64 nlookup)
  81 {
  82         struct fuse_forget_in *inarg = &req->misc.forget_in;
  83         inarg->nlookup = nlookup;
  84         req->in.h.opcode = FUSE_FORGET;
  85         req->in.h.nodeid = nodeid;
  86         req->in.numargs = 1;
  87         req->in.args[0].size = sizeof(struct fuse_forget_in);
  88         req->in.args[0].value = inarg;
  89         request_send_noreply(fc, req);
  90 }
  91
  92 static void fuse_clear_inode(struct inode *inode)
  93 {
  94         if (inode->i_sb->s_flags & MS_ACTIVE) {
  95                 struct fuse_conn *fc = get_fuse_conn(inode);
  96                 struct fuse_inode *fi = get_fuse_inode(inode);
  97                 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
  98                 fi->forget_req = NULL;
  99         }
 100 }
 101
 102 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 103 {
 104         if (*flags & MS_MANDLOCK)
 105                 return -EINVAL;
 106
 107         return 0;
 108 }
 109
 110 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
 111 {
 112         struct fuse_conn *fc = get_fuse_conn(inode);
 113         if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
 114                 invalidate_inode_pages(inode->i_mapping);
 115
 116         inode->i_ino     = attr->ino;
 117         inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
 118         inode->i_nlink   = attr->nlink;
 119         inode->i_uid     = attr->uid;
 120         inode->i_gid     = attr->gid;
 121         spin_lock(&fc->lock);
 122         i_size_write(inode, attr->size);
 123         spin_unlock(&fc->lock);
 124         inode->i_blocks  = attr->blocks;
 125         inode->i_atime.tv_sec   = attr->atime;
 126         inode->i_atime.tv_nsec  = attr->atimensec;
 127         inode->i_mtime.tv_sec   = attr->mtime;
 128         inode->i_mtime.tv_nsec  = attr->mtimensec;
 129         inode->i_ctime.tv_sec   = attr->ctime;
 130         inode->i_ctime.tv_nsec  = attr->ctimensec;
 131 }
 132
 133 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 134 {
 135         inode->i_mode = attr->mode & S_IFMT;
 136         inode->i_size = attr->size;
 137         if (S_ISREG(inode->i_mode)) {
 138                 fuse_init_common(inode);
 139                 fuse_init_file_inode(inode);
 140         } else if (S_ISDIR(inode->i_mode))
 141                 fuse_init_dir(inode);
 142         else if (S_ISLNK(inode->i_mode))
 143                 fuse_init_symlink(inode);
 144         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 145                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 146                 fuse_init_common(inode);
 147                 init_special_inode(inode, inode->i_mode,
 148                                    new_decode_dev(attr->rdev));
 149         } else
 150                 BUG();
 151 }
 152
 153 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 154 {
 155         unsigned long nodeid = *(unsigned long *) _nodeidp;
 156         if (get_node_id(inode) == nodeid)
 157                 return 1;
 158         else
 159                 return 0;
 160 }
 161
 162 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 163 {
 164         unsigned long nodeid = *(unsigned long *) _nodeidp;
 165         get_fuse_inode(inode)->nodeid = nodeid;
 166         return 0;
 167 }
 168
 169 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 170                         int generation, struct fuse_attr *attr)
 171 {
 172         struct inode *inode;
 173         struct fuse_inode *fi;
 174         struct fuse_conn *fc = get_fuse_conn_super(sb);
 175
 176  retry:
 177         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 178         if (!inode)
 179                 return NULL;
 180
 181         if ((inode->i_state & I_NEW)) {
 182                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
 183                 inode->i_generation = generation;
 184                 inode->i_data.backing_dev_info = &fc->bdi;
 185                 fuse_init_inode(inode, attr);
 186                 unlock_new_inode(inode);
 187         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 188                 /* Inode has changed type, any I/O on the old should fail */
 189                 make_bad_inode(inode);
 190                 iput(inode);
 191                 goto retry;
 192         }
 193
 194         fi = get_fuse_inode(inode);
 195         spin_lock(&fc->lock);
 196         fi->nlookup ++;
 197         spin_unlock(&fc->lock);
 198         fuse_change_attributes(inode, attr);
 199         return inode;
 200 }
 201
 202 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
 203 {
 204         if (flags & MNT_FORCE)
 205                 fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
 206 }
 207
 208 static void fuse_put_super(struct super_block *sb)
 209 {
 210         struct fuse_conn *fc = get_fuse_conn_super(sb);
 211
 212         spin_lock(&fc->lock);
 213         fc->connected = 0;
 214         fc->blocked = 0;
 215         spin_unlock(&fc->lock);
 216         /* Flush all readers on this fs */
 217         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 218         wake_up_all(&fc->waitq);
 219         wake_up_all(&fc->blocked_waitq);
 220         mutex_lock(&fuse_mutex);
 221         list_del(&fc->entry);
 222         fuse_ctl_remove_conn(fc);
 223         mutex_unlock(&fuse_mutex);
 224         fuse_conn_put(fc);
 225 }
 226
 227 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 228 {
 229         stbuf->f_type    = FUSE_SUPER_MAGIC;
 230         stbuf->f_bsize   = attr->bsize;
 231         stbuf->f_frsize  = attr->frsize;
 232         stbuf->f_blocks  = attr->blocks;
 233         stbuf->f_bfree   = attr->bfree;
 234         stbuf->f_bavail  = attr->bavail;
 235         stbuf->f_files   = attr->files;
 236         stbuf->f_ffree   = attr->ffree;
 237         stbuf->f_namelen = attr->namelen;
 238         /* fsid is left zero */
 239 }
 240
 241 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 242 {
 243         struct super_block *sb = dentry->d_sb;
 244         struct fuse_conn *fc = get_fuse_conn_super(sb);
 245         struct fuse_req *req;
 246         struct fuse_statfs_out outarg;
 247         int err;
 248
 249         req = fuse_get_req(fc);
 250         if (IS_ERR(req))
 251                 return PTR_ERR(req);
 252
 253         memset(&outarg, 0, sizeof(outarg));
 254         req->in.numargs = 0;
 255         req->in.h.opcode = FUSE_STATFS;
 256         req->in.h.nodeid = get_node_id(dentry->d_inode);
 257         req->out.numargs = 1;
 258         req->out.args[0].size =
 259                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 260         req->out.args[0].value = &outarg;
 261         request_send(fc, req);
 262         err = req->out.h.error;
 263         if (!err)
 264                 convert_fuse_statfs(buf, &outarg.st);
 265         fuse_put_request(fc, req);
 266         return err;
 267 }
 268
 269 enum {
 270         OPT_FD,
 271         OPT_ROOTMODE,
 272         OPT_USER_ID,
 273         OPT_GROUP_ID,
 274         OPT_DEFAULT_PERMISSIONS,
 275         OPT_ALLOW_OTHER,
 276         OPT_MAX_READ,
 277         OPT_ERR
 278 };
 279
 280 static match_table_t tokens = {
 281         {OPT_FD,                        "fd=%u"},
 282         {OPT_ROOTMODE,                  "rootmode=%o"},
 283         {OPT_USER_ID,                   "user_id=%u"},
 284         {OPT_GROUP_ID,                  "group_id=%u"},
 285         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 286         {OPT_ALLOW_OTHER,               "allow_other"},
 287         {OPT_MAX_READ,                  "max_read=%u"},
 288         {OPT_ERR,                       NULL}
 289 };
 290
 291 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
 292 {
 293         char *p;
 294         memset(d, 0, sizeof(struct fuse_mount_data));
 295         d->max_read = ~0;
 296
 297         while ((p = strsep(&opt, ",")) != NULL) {
 298                 int token;
 299                 int value;
 300                 substring_t args[MAX_OPT_ARGS];
 301                 if (!*p)
 302                         continue;
 303
 304                 token = match_token(p, tokens, args);
 305                 switch (token) {
 306                 case OPT_FD:
 307                         if (match_int(&args[0], &value))
 308                                 return 0;
 309                         d->fd = value;
 310                         d->fd_present = 1;
 311                         break;
 312
 313                 case OPT_ROOTMODE:
 314                         if (match_octal(&args[0], &value))
 315                                 return 0;
 316                         d->rootmode = value;
 317                         d->rootmode_present = 1;
 318                         break;
 319
 320                 case OPT_USER_ID:
 321                         if (match_int(&args[0], &value))
 322                                 return 0;
 323                         d->user_id = value;
 324                         d->user_id_present = 1;
 325                         break;
 326
 327                 case OPT_GROUP_ID:
 328                         if (match_int(&args[0], &value))
 329                                 return 0;
 330                         d->group_id = value;
 331                         d->group_id_present = 1;
 332                         break;
 333
 334                 case OPT_DEFAULT_PERMISSIONS:
 335                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 336                         break;
 337
 338                 case OPT_ALLOW_OTHER:
 339                         d->flags |= FUSE_ALLOW_OTHER;
 340                         break;
 341
 342                 case OPT_MAX_READ:
 343                         if (match_int(&args[0], &value))
 344                                 return 0;
 345                         d->max_read = value;
 346                         break;
 347
 348                 default:
 349                         return 0;
 350                 }
 351         }
 352
 353         if (!d->fd_present || !d->rootmode_present ||
 354             !d->user_id_present || !d->group_id_present)
 355                 return 0;
 356
 357         return 1;
 358 }
 359
 360 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 361 {
 362         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 363
 364         seq_printf(m, ",user_id=%u", fc->user_id);
 365         seq_printf(m, ",group_id=%u", fc->group_id);
 366         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 367                 seq_puts(m, ",default_permissions");
 368         if (fc->flags & FUSE_ALLOW_OTHER)
 369                 seq_puts(m, ",allow_other");
 370         if (fc->max_read != ~0)
 371                 seq_printf(m, ",max_read=%u", fc->max_read);
 372         return 0;
 373 }
 374
 375 static struct fuse_conn *new_conn(void)
 376 {
 377         struct fuse_conn *fc;
 378
 379         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 380         if (fc) {
 381                 spin_lock_init(&fc->lock);
 382                 mutex_init(&fc->inst_mutex);
 383                 atomic_set(&fc->count, 1);
 384                 init_waitqueue_head(&fc->waitq);
 385                 init_waitqueue_head(&fc->blocked_waitq);
 386                 INIT_LIST_HEAD(&fc->pending);
 387                 INIT_LIST_HEAD(&fc->processing);
 388                 INIT_LIST_HEAD(&fc->io);
 389                 INIT_LIST_HEAD(&fc->interrupts);
 390                 atomic_set(&fc->num_waiting, 0);
 391                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 392                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 393                 fc->reqctr = 0;
 394                 fc->blocked = 1;
 395                 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 396         }
 397         return fc;
 398 }
 399
 400 void fuse_conn_put(struct fuse_conn *fc)
 401 {
 402         if (atomic_dec_and_test(&fc->count)) {
 403                 mutex_destroy(&fc->inst_mutex);
 404                 kfree(fc);
 405         }
 406 }
 407
 408 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 409 {
 410         atomic_inc(&fc->count);
 411         return fc;
 412 }
 413
 414 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 415 {
 416         struct fuse_attr attr;
 417         memset(&attr, 0, sizeof(attr));
 418
 419         attr.mode = mode;
 420         attr.ino = FUSE_ROOT_ID;
 421         return fuse_iget(sb, 1, 0, &attr);
 422 }
 423
 424 static struct super_operations fuse_super_operations = {
 425         .alloc_inode    = fuse_alloc_inode,
 426         .destroy_inode  = fuse_destroy_inode,
 427         .read_inode     = fuse_read_inode,
 428         .clear_inode    = fuse_clear_inode,
 429         .remount_fs     = fuse_remount_fs,
 430         .put_super      = fuse_put_super,
 431         .umount_begin   = fuse_umount_begin,
 432         .statfs         = fuse_statfs,
 433         .show_options   = fuse_show_options,
 434 };
 435
 436 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 437 {
 438         struct fuse_init_out *arg = &req->misc.init_out;
 439
 440         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 441                 fc->conn_error = 1;
 442         else {
 443                 unsigned long ra_pages;
 444
 445                 if (arg->minor >= 6) {
 446                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 447                         if (arg->flags & FUSE_ASYNC_READ)
 448                                 fc->async_read = 1;
 449                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 450                                 fc->no_lock = 1;
 451                 } else {
 452                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 453                         fc->no_lock = 1;
 454                 }
 455
 456                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 457                 fc->minor = arg->minor;
 458                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 459         }
 460         fuse_put_request(fc, req);
 461         fc->blocked = 0;
 462         wake_up_all(&fc->blocked_waitq);
 463 }
 464
 465 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 466 {
 467         struct fuse_init_in *arg = &req->misc.init_in;
 468
 469         arg->major = FUSE_KERNEL_VERSION;
 470         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 471         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 472         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
 473         req->in.h.opcode = FUSE_INIT;
 474         req->in.numargs = 1;
 475         req->in.args[0].size = sizeof(*arg);
 476         req->in.args[0].value = arg;
 477         req->out.numargs = 1;
 478         /* Variable length arguement used for backward compatibility
 479            with interface version < 7.5.  Rest of init_out is zeroed
 480            by do_get_request(), so a short reply is not a problem */
 481         req->out.argvar = 1;
 482         req->out.args[0].size = sizeof(struct fuse_init_out);
 483         req->out.args[0].value = &req->misc.init_out;
 484         req->end = process_init_reply;
 485         request_send_background(fc, req);
 486 }
 487
 488 static u64 conn_id(void)
 489 {
 490         static u64 ctr = 1;
 491         return ctr++;
 492 }
 493
 494 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 495 {
 496         struct fuse_conn *fc;
 497         struct inode *root;
 498         struct fuse_mount_data d;
 499         struct file *file;
 500         struct dentry *root_dentry;
 501         struct fuse_req *init_req;
 502         int err;
 503
 504         if (sb->s_flags & MS_MANDLOCK)
 505                 return -EINVAL;
 506
 507         if (!parse_fuse_opt((char *) data, &d))
 508                 return -EINVAL;
 509
 510         sb->s_blocksize = PAGE_CACHE_SIZE;
 511         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 512         sb->s_magic = FUSE_SUPER_MAGIC;
 513         sb->s_op = &fuse_super_operations;
 514         sb->s_maxbytes = MAX_LFS_FILESIZE;
 515
 516         file = fget(d.fd);
 517         if (!file)
 518                 return -EINVAL;
 519
 520         if (file->f_op != &fuse_dev_operations)
 521                 return -EINVAL;
 522
 523         fc = new_conn();
 524         if (!fc)
 525                 return -ENOMEM;
 526
 527         fc->flags = d.flags;
 528         fc->user_id = d.user_id;
 529         fc->group_id = d.group_id;
 530         fc->max_read = d.max_read;
 531
 532         /* Used by get_root_inode() */
 533         sb->s_fs_info = fc;
 534
 535         err = -ENOMEM;
 536         root = get_root_inode(sb, d.rootmode);
 537         if (!root)
 538                 goto err;
 539
 540         root_dentry = d_alloc_root(root);
 541         if (!root_dentry) {
 542                 iput(root);
 543                 goto err;
 544         }
 545
 546         init_req = fuse_request_alloc();
 547         if (!init_req)
 548                 goto err_put_root;
 549
 550         mutex_lock(&fuse_mutex);
 551         err = -EINVAL;
 552         if (file->private_data)
 553                 goto err_unlock;
 554
 555         fc->id = conn_id();
 556         err = fuse_ctl_add_conn(fc);
 557         if (err)
 558                 goto err_unlock;
 559
 560         list_add_tail(&fc->entry, &fuse_conn_list);
 561         sb->s_root = root_dentry;
 562         fc->connected = 1;
 563         file->private_data = fuse_conn_get(fc);
 564         mutex_unlock(&fuse_mutex);
 565         /*
 566          * atomic_dec_and_test() in fput() provides the necessary
 567          * memory barrier for file->private_data to be visible on all
 568          * CPUs after this
 569          */
 570         fput(file);
 571
 572         fuse_send_init(fc, init_req);
 573
 574         return 0;
 575
 576  err_unlock:
 577         mutex_unlock(&fuse_mutex);
 578         fuse_request_free(init_req);
 579  err_put_root:
 580         dput(root_dentry);
 581  err:
 582         fput(file);
 583         fuse_conn_put(fc);
 584         return err;
 585 }
 586
 587 static int fuse_get_sb(struct file_system_type *fs_type,
 588                        int flags, const char *dev_name,
 589                        void *raw_data, struct vfsmount *mnt)
 590 {
 591         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 592 }
 593
 594 static struct file_system_type fuse_fs_type = {
 595         .owner          = THIS_MODULE,
 596         .name           = "fuse",
 597         .get_sb         = fuse_get_sb,
 598         .kill_sb        = kill_anon_super,
 599 };
 600
 601 static decl_subsys(fuse, NULL, NULL);
 602 static decl_subsys(connections, NULL, NULL);
 603
 604 static void fuse_inode_init_once(void *foo, struct kmem_cache *cachep,
 605                                  unsigned long flags)
 606 {
 607         struct inode * inode = foo;
 608
 609         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 610             SLAB_CTOR_CONSTRUCTOR)
 611                 inode_init_once(inode);
 612 }
 613
 614 static int __init fuse_fs_init(void)
 615 {
 616         int err;
 617
 618         err = register_filesystem(&fuse_fs_type);
 619         if (err)
 620                 printk("fuse: failed to register filesystem\n");
 621         else {
 622                 fuse_inode_cachep = kmem_cache_create("fuse_inode",
 623                                                       sizeof(struct fuse_inode),
 624                                                       0, SLAB_HWCACHE_ALIGN,
 625                                                       fuse_inode_init_once, NULL);
 626                 if (!fuse_inode_cachep) {
 627                         unregister_filesystem(&fuse_fs_type);
 628                         err = -ENOMEM;
 629                 }
 630         }
 631
 632         return err;
 633 }
 634
 635 static void fuse_fs_cleanup(void)
 636 {
 637         unregister_filesystem(&fuse_fs_type);
 638         kmem_cache_destroy(fuse_inode_cachep);
 639 }
 640
 641 static int fuse_sysfs_init(void)
 642 {
 643         int err;
 644
 645         kset_set_kset_s(&fuse_subsys, fs_subsys);
 646         err = subsystem_register(&fuse_subsys);
 647         if (err)
 648                 goto out_err;
 649
 650         kset_set_kset_s(&connections_subsys, fuse_subsys);
 651         err = subsystem_register(&connections_subsys);
 652         if (err)
 653                 goto out_fuse_unregister;
 654
 655         return 0;
 656
 657  out_fuse_unregister:
 658         subsystem_unregister(&fuse_subsys);
 659  out_err:
 660         return err;
 661 }
 662
 663 static void fuse_sysfs_cleanup(void)
 664 {
 665         subsystem_unregister(&connections_subsys);
 666         subsystem_unregister(&fuse_subsys);
 667 }
 668
 669 static int __init fuse_init(void)
 670 {
 671         int res;
 672
 673         printk("fuse init (API version %i.%i)\n",
 674                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 675
 676         INIT_LIST_HEAD(&fuse_conn_list);
 677         res = fuse_fs_init();
 678         if (res)
 679                 goto err;
 680
 681         res = fuse_dev_init();
 682         if (res)
 683                 goto err_fs_cleanup;
 684
 685         res = fuse_sysfs_init();
 686         if (res)
 687                 goto err_dev_cleanup;
 688
 689         res = fuse_ctl_init();
 690         if (res)
 691                 goto err_sysfs_cleanup;
 692
 693         return 0;
 694
 695  err_sysfs_cleanup:
 696         fuse_sysfs_cleanup();
 697  err_dev_cleanup:
 698         fuse_dev_cleanup();
 699  err_fs_cleanup:
 700         fuse_fs_cleanup();
 701  err:
 702         return res;
 703 }
 704
 705 static void __exit fuse_exit(void)
 706 {
 707         printk(KERN_DEBUG "fuse exit\n");
 708
 709         fuse_ctl_cleanup();
 710         fuse_sysfs_cleanup();
 711         fuse_fs_cleanup();
 712         fuse_dev_cleanup();
 713 }
 714
 715 module_init(fuse_init);
 716 module_exit(fuse_exit);