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 #include <linux/sched.h>
  21
  22 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
  23 MODULE_DESCRIPTION("Filesystem in Userspace");
  24 MODULE_LICENSE("GPL");
  25
  26 static struct kmem_cache *fuse_inode_cachep;
  27 struct list_head fuse_conn_list;
  28 DEFINE_MUTEX(fuse_mutex);
  29
  30 #define FUSE_SUPER_MAGIC 0x65735546
  31
  32 struct fuse_mount_data {
  33         int fd;
  34         unsigned rootmode;
  35         unsigned user_id;
  36         unsigned group_id;
  37         unsigned fd_present : 1;
  38         unsigned rootmode_present : 1;
  39         unsigned user_id_present : 1;
  40         unsigned group_id_present : 1;
  41         unsigned flags;
  42         unsigned max_read;
  43         unsigned blksize;
  44 };
  45
  46 static struct inode *fuse_alloc_inode(struct super_block *sb)
  47 {
  48         struct inode *inode;
  49         struct fuse_inode *fi;
  50
  51         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
  52         if (!inode)
  53                 return NULL;
  54
  55         fi = get_fuse_inode(inode);
  56         fi->i_time = 0;
  57         fi->nodeid = 0;
  58         fi->nlookup = 0;
  59         fi->forget_req = fuse_request_alloc();
  60         if (!fi->forget_req) {
  61                 kmem_cache_free(fuse_inode_cachep, inode);
  62                 return NULL;
  63         }
  64
  65         return inode;
  66 }
  67
  68 static void fuse_destroy_inode(struct inode *inode)
  69 {
  70         struct fuse_inode *fi = get_fuse_inode(inode);
  71         if (fi->forget_req)
  72                 fuse_request_free(fi->forget_req);
  73         kmem_cache_free(fuse_inode_cachep, inode);
  74 }
  75
  76 static void fuse_read_inode(struct inode *inode)
  77 {
  78         /* No op */
  79 }
  80
  81 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
  82                       unsigned long nodeid, u64 nlookup)
  83 {
  84         struct fuse_forget_in *inarg = &req->misc.forget_in;
  85         inarg->nlookup = nlookup;
  86         req->in.h.opcode = FUSE_FORGET;
  87         req->in.h.nodeid = nodeid;
  88         req->in.numargs = 1;
  89         req->in.args[0].size = sizeof(struct fuse_forget_in);
  90         req->in.args[0].value = inarg;
  91         request_send_noreply(fc, req);
  92 }
  93
  94 static void fuse_clear_inode(struct inode *inode)
  95 {
  96         if (inode->i_sb->s_flags & MS_ACTIVE) {
  97                 struct fuse_conn *fc = get_fuse_conn(inode);
  98                 struct fuse_inode *fi = get_fuse_inode(inode);
  99                 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
 100                 fi->forget_req = NULL;
 101         }
 102 }
 103
 104 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 105 {
 106         if (*flags & MS_MANDLOCK)
 107                 return -EINVAL;
 108
 109         return 0;
 110 }
 111
 112 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
 113 {
 114         struct fuse_conn *fc = get_fuse_conn(inode);
 115         if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
 116                 invalidate_mapping_pages(inode->i_mapping, 0, -1);
 117
 118         inode->i_ino     = attr->ino;
 119         inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
 120         inode->i_nlink   = attr->nlink;
 121         inode->i_uid     = attr->uid;
 122         inode->i_gid     = attr->gid;
 123         spin_lock(&fc->lock);
 124         i_size_write(inode, attr->size);
 125         spin_unlock(&fc->lock);
 126         inode->i_blocks  = attr->blocks;
 127         inode->i_atime.tv_sec   = attr->atime;
 128         inode->i_atime.tv_nsec  = attr->atimensec;
 129         inode->i_mtime.tv_sec   = attr->mtime;
 130         inode->i_mtime.tv_nsec  = attr->mtimensec;
 131         inode->i_ctime.tv_sec   = attr->ctime;
 132         inode->i_ctime.tv_nsec  = attr->ctimensec;
 133 }
 134
 135 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 136 {
 137         inode->i_mode = attr->mode & S_IFMT;
 138         inode->i_size = attr->size;
 139         if (S_ISREG(inode->i_mode)) {
 140                 fuse_init_common(inode);
 141                 fuse_init_file_inode(inode);
 142         } else if (S_ISDIR(inode->i_mode))
 143                 fuse_init_dir(inode);
 144         else if (S_ISLNK(inode->i_mode))
 145                 fuse_init_symlink(inode);
 146         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 147                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 148                 fuse_init_common(inode);
 149                 init_special_inode(inode, inode->i_mode,
 150                                    new_decode_dev(attr->rdev));
 151         } else
 152                 BUG();
 153 }
 154
 155 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 156 {
 157         unsigned long nodeid = *(unsigned long *) _nodeidp;
 158         if (get_node_id(inode) == nodeid)
 159                 return 1;
 160         else
 161                 return 0;
 162 }
 163
 164 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 165 {
 166         unsigned long nodeid = *(unsigned long *) _nodeidp;
 167         get_fuse_inode(inode)->nodeid = nodeid;
 168         return 0;
 169 }
 170
 171 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 172                         int generation, struct fuse_attr *attr)
 173 {
 174         struct inode *inode;
 175         struct fuse_inode *fi;
 176         struct fuse_conn *fc = get_fuse_conn_super(sb);
 177
 178  retry:
 179         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 180         if (!inode)
 181                 return NULL;
 182
 183         if ((inode->i_state & I_NEW)) {
 184                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
 185                 inode->i_generation = generation;
 186                 inode->i_data.backing_dev_info = &fc->bdi;
 187                 fuse_init_inode(inode, attr);
 188                 unlock_new_inode(inode);
 189         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 190                 /* Inode has changed type, any I/O on the old should fail */
 191                 make_bad_inode(inode);
 192                 iput(inode);
 193                 goto retry;
 194         }
 195
 196         fi = get_fuse_inode(inode);
 197         spin_lock(&fc->lock);
 198         fi->nlookup ++;
 199         spin_unlock(&fc->lock);
 200         fuse_change_attributes(inode, attr);
 201         return inode;
 202 }
 203
 204 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
 205 {
 206         if (flags & MNT_FORCE)
 207                 fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
 208 }
 209
 210 static void fuse_send_destroy(struct fuse_conn *fc)
 211 {
 212         struct fuse_req *req = fc->destroy_req;
 213         if (req && fc->conn_init) {
 214                 fc->destroy_req = NULL;
 215                 req->in.h.opcode = FUSE_DESTROY;
 216                 req->force = 1;
 217                 request_send(fc, req);
 218                 fuse_put_request(fc, req);
 219         }
 220 }
 221
 222 static void fuse_put_super(struct super_block *sb)
 223 {
 224         struct fuse_conn *fc = get_fuse_conn_super(sb);
 225
 226         fuse_send_destroy(fc);
 227         spin_lock(&fc->lock);
 228         fc->connected = 0;
 229         fc->blocked = 0;
 230         spin_unlock(&fc->lock);
 231         /* Flush all readers on this fs */
 232         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 233         wake_up_all(&fc->waitq);
 234         wake_up_all(&fc->blocked_waitq);
 235         mutex_lock(&fuse_mutex);
 236         list_del(&fc->entry);
 237         fuse_ctl_remove_conn(fc);
 238         mutex_unlock(&fuse_mutex);
 239         fuse_conn_put(fc);
 240 }
 241
 242 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 243 {
 244         stbuf->f_type    = FUSE_SUPER_MAGIC;
 245         stbuf->f_bsize   = attr->bsize;
 246         stbuf->f_frsize  = attr->frsize;
 247         stbuf->f_blocks  = attr->blocks;
 248         stbuf->f_bfree   = attr->bfree;
 249         stbuf->f_bavail  = attr->bavail;
 250         stbuf->f_files   = attr->files;
 251         stbuf->f_ffree   = attr->ffree;
 252         stbuf->f_namelen = attr->namelen;
 253         /* fsid is left zero */
 254 }
 255
 256 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 257 {
 258         struct super_block *sb = dentry->d_sb;
 259         struct fuse_conn *fc = get_fuse_conn_super(sb);
 260         struct fuse_req *req;
 261         struct fuse_statfs_out outarg;
 262         int err;
 263
 264         req = fuse_get_req(fc);
 265         if (IS_ERR(req))
 266                 return PTR_ERR(req);
 267
 268         memset(&outarg, 0, sizeof(outarg));
 269         req->in.numargs = 0;
 270         req->in.h.opcode = FUSE_STATFS;
 271         req->in.h.nodeid = get_node_id(dentry->d_inode);
 272         req->out.numargs = 1;
 273         req->out.args[0].size =
 274                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 275         req->out.args[0].value = &outarg;
 276         request_send(fc, req);
 277         err = req->out.h.error;
 278         if (!err)
 279                 convert_fuse_statfs(buf, &outarg.st);
 280         fuse_put_request(fc, req);
 281         return err;
 282 }
 283
 284 enum {
 285         OPT_FD,
 286         OPT_ROOTMODE,
 287         OPT_USER_ID,
 288         OPT_GROUP_ID,
 289         OPT_DEFAULT_PERMISSIONS,
 290         OPT_ALLOW_OTHER,
 291         OPT_MAX_READ,
 292         OPT_BLKSIZE,
 293         OPT_ERR
 294 };
 295
 296 static match_table_t tokens = {
 297         {OPT_FD,                        "fd=%u"},
 298         {OPT_ROOTMODE,                  "rootmode=%o"},
 299         {OPT_USER_ID,                   "user_id=%u"},
 300         {OPT_GROUP_ID,                  "group_id=%u"},
 301         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 302         {OPT_ALLOW_OTHER,               "allow_other"},
 303         {OPT_MAX_READ,                  "max_read=%u"},
 304         {OPT_BLKSIZE,                   "blksize=%u"},
 305         {OPT_ERR,                       NULL}
 306 };
 307
 308 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 309 {
 310         char *p;
 311         memset(d, 0, sizeof(struct fuse_mount_data));
 312         d->max_read = ~0;
 313         d->blksize = 512;
 314
 315         while ((p = strsep(&opt, ",")) != NULL) {
 316                 int token;
 317                 int value;
 318                 substring_t args[MAX_OPT_ARGS];
 319                 if (!*p)
 320                         continue;
 321
 322                 token = match_token(p, tokens, args);
 323                 switch (token) {
 324                 case OPT_FD:
 325                         if (match_int(&args[0], &value))
 326                                 return 0;
 327                         d->fd = value;
 328                         d->fd_present = 1;
 329                         break;
 330
 331                 case OPT_ROOTMODE:
 332                         if (match_octal(&args[0], &value))
 333                                 return 0;
 334                         if (!fuse_valid_type(value))
 335                                 return 0;
 336                         d->rootmode = value;
 337                         d->rootmode_present = 1;
 338                         break;
 339
 340                 case OPT_USER_ID:
 341                         if (match_int(&args[0], &value))
 342                                 return 0;
 343                         d->user_id = value;
 344                         d->user_id_present = 1;
 345                         break;
 346
 347                 case OPT_GROUP_ID:
 348                         if (match_int(&args[0], &value))
 349                                 return 0;
 350                         d->group_id = value;
 351                         d->group_id_present = 1;
 352                         break;
 353
 354                 case OPT_DEFAULT_PERMISSIONS:
 355                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 356                         break;
 357
 358                 case OPT_ALLOW_OTHER:
 359                         d->flags |= FUSE_ALLOW_OTHER;
 360                         break;
 361
 362                 case OPT_MAX_READ:
 363                         if (match_int(&args[0], &value))
 364                                 return 0;
 365                         d->max_read = value;
 366                         break;
 367
 368                 case OPT_BLKSIZE:
 369                         if (!is_bdev || match_int(&args[0], &value))
 370                                 return 0;
 371                         d->blksize = value;
 372                         break;
 373
 374                 default:
 375                         return 0;
 376                 }
 377         }
 378
 379         if (!d->fd_present || !d->rootmode_present ||
 380             !d->user_id_present || !d->group_id_present)
 381                 return 0;
 382
 383         return 1;
 384 }
 385
 386 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 387 {
 388         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 389
 390         seq_printf(m, ",user_id=%u", fc->user_id);
 391         seq_printf(m, ",group_id=%u", fc->group_id);
 392         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 393                 seq_puts(m, ",default_permissions");
 394         if (fc->flags & FUSE_ALLOW_OTHER)
 395                 seq_puts(m, ",allow_other");
 396         if (fc->max_read != ~0)
 397                 seq_printf(m, ",max_read=%u", fc->max_read);
 398         return 0;
 399 }
 400
 401 static struct fuse_conn *new_conn(void)
 402 {
 403         struct fuse_conn *fc;
 404
 405         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 406         if (fc) {
 407                 spin_lock_init(&fc->lock);
 408                 mutex_init(&fc->inst_mutex);
 409                 atomic_set(&fc->count, 1);
 410                 init_waitqueue_head(&fc->waitq);
 411                 init_waitqueue_head(&fc->blocked_waitq);
 412                 INIT_LIST_HEAD(&fc->pending);
 413                 INIT_LIST_HEAD(&fc->processing);
 414                 INIT_LIST_HEAD(&fc->io);
 415                 INIT_LIST_HEAD(&fc->interrupts);
 416                 atomic_set(&fc->num_waiting, 0);
 417                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 418                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 419                 fc->reqctr = 0;
 420                 fc->blocked = 1;
 421                 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 422         }
 423         return fc;
 424 }
 425
 426 void fuse_conn_put(struct fuse_conn *fc)
 427 {
 428         if (atomic_dec_and_test(&fc->count)) {
 429                 if (fc->destroy_req)
 430                         fuse_request_free(fc->destroy_req);
 431                 mutex_destroy(&fc->inst_mutex);
 432                 kfree(fc);
 433         }
 434 }
 435
 436 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 437 {
 438         atomic_inc(&fc->count);
 439         return fc;
 440 }
 441
 442 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 443 {
 444         struct fuse_attr attr;
 445         memset(&attr, 0, sizeof(attr));
 446
 447         attr.mode = mode;
 448         attr.ino = FUSE_ROOT_ID;
 449         return fuse_iget(sb, 1, 0, &attr);
 450 }
 451
 452 static const struct super_operations fuse_super_operations = {
 453         .alloc_inode    = fuse_alloc_inode,
 454         .destroy_inode  = fuse_destroy_inode,
 455         .read_inode     = fuse_read_inode,
 456         .clear_inode    = fuse_clear_inode,
 457         .drop_inode     = generic_delete_inode,
 458         .remount_fs     = fuse_remount_fs,
 459         .put_super      = fuse_put_super,
 460         .umount_begin   = fuse_umount_begin,
 461         .statfs         = fuse_statfs,
 462         .show_options   = fuse_show_options,
 463 };
 464
 465 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 466 {
 467         struct fuse_init_out *arg = &req->misc.init_out;
 468
 469         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 470                 fc->conn_error = 1;
 471         else {
 472                 unsigned long ra_pages;
 473
 474                 if (arg->minor >= 6) {
 475                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 476                         if (arg->flags & FUSE_ASYNC_READ)
 477                                 fc->async_read = 1;
 478                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 479                                 fc->no_lock = 1;
 480                 } else {
 481                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 482                         fc->no_lock = 1;
 483                 }
 484
 485                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 486                 fc->minor = arg->minor;
 487                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 488                 fc->conn_init = 1;
 489         }
 490         fuse_put_request(fc, req);
 491         fc->blocked = 0;
 492         wake_up_all(&fc->blocked_waitq);
 493 }
 494
 495 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 496 {
 497         struct fuse_init_in *arg = &req->misc.init_in;
 498
 499         arg->major = FUSE_KERNEL_VERSION;
 500         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 501         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 502         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
 503         req->in.h.opcode = FUSE_INIT;
 504         req->in.numargs = 1;
 505         req->in.args[0].size = sizeof(*arg);
 506         req->in.args[0].value = arg;
 507         req->out.numargs = 1;
 508         /* Variable length arguement used for backward compatibility
 509            with interface version < 7.5.  Rest of init_out is zeroed
 510            by do_get_request(), so a short reply is not a problem */
 511         req->out.argvar = 1;
 512         req->out.args[0].size = sizeof(struct fuse_init_out);
 513         req->out.args[0].value = &req->misc.init_out;
 514         req->end = process_init_reply;
 515         request_send_background(fc, req);
 516 }
 517
 518 static u64 conn_id(void)
 519 {
 520         static u64 ctr = 1;
 521         return ctr++;
 522 }
 523
 524 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 525 {
 526         struct fuse_conn *fc;
 527         struct inode *root;
 528         struct fuse_mount_data d;
 529         struct file *file;
 530         struct dentry *root_dentry;
 531         struct fuse_req *init_req;
 532         int err;
 533         int is_bdev = sb->s_bdev != NULL;
 534
 535         if (sb->s_flags & MS_MANDLOCK)
 536                 return -EINVAL;
 537
 538         if (!parse_fuse_opt((char *) data, &d, is_bdev))
 539                 return -EINVAL;
 540
 541         if (is_bdev) {
 542 #ifdef CONFIG_BLOCK
 543                 if (!sb_set_blocksize(sb, d.blksize))
 544                         return -EINVAL;
 545 #endif
 546         } else {
 547                 sb->s_blocksize = PAGE_CACHE_SIZE;
 548                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 549         }
 550         sb->s_magic = FUSE_SUPER_MAGIC;
 551         sb->s_op = &fuse_super_operations;
 552         sb->s_maxbytes = MAX_LFS_FILESIZE;
 553
 554         file = fget(d.fd);
 555         if (!file)
 556                 return -EINVAL;
 557
 558         if (file->f_op != &fuse_dev_operations)
 559                 return -EINVAL;
 560
 561         fc = new_conn();
 562         if (!fc)
 563                 return -ENOMEM;
 564
 565         fc->flags = d.flags;
 566         fc->user_id = d.user_id;
 567         fc->group_id = d.group_id;
 568         fc->max_read = d.max_read;
 569
 570         /* Used by get_root_inode() */
 571         sb->s_fs_info = fc;
 572
 573         err = -ENOMEM;
 574         root = get_root_inode(sb, d.rootmode);
 575         if (!root)
 576                 goto err;
 577
 578         root_dentry = d_alloc_root(root);
 579         if (!root_dentry) {
 580                 iput(root);
 581                 goto err;
 582         }
 583
 584         init_req = fuse_request_alloc();
 585         if (!init_req)
 586                 goto err_put_root;
 587
 588         if (is_bdev) {
 589                 fc->destroy_req = fuse_request_alloc();
 590                 if (!fc->destroy_req)
 591                         goto err_put_root;
 592         }
 593
 594         mutex_lock(&fuse_mutex);
 595         err = -EINVAL;
 596         if (file->private_data)
 597                 goto err_unlock;
 598
 599         fc->id = conn_id();
 600         err = fuse_ctl_add_conn(fc);
 601         if (err)
 602                 goto err_unlock;
 603
 604         list_add_tail(&fc->entry, &fuse_conn_list);
 605         sb->s_root = root_dentry;
 606         fc->connected = 1;
 607         file->private_data = fuse_conn_get(fc);
 608         mutex_unlock(&fuse_mutex);
 609         /*
 610          * atomic_dec_and_test() in fput() provides the necessary
 611          * memory barrier for file->private_data to be visible on all
 612          * CPUs after this
 613          */
 614         fput(file);
 615
 616         fuse_send_init(fc, init_req);
 617
 618         return 0;
 619
 620  err_unlock:
 621         mutex_unlock(&fuse_mutex);
 622         fuse_request_free(init_req);
 623  err_put_root:
 624         dput(root_dentry);
 625  err:
 626         fput(file);
 627         fuse_conn_put(fc);
 628         return err;
 629 }
 630
 631 static int fuse_get_sb(struct file_system_type *fs_type,
 632                        int flags, const char *dev_name,
 633                        void *raw_data, struct vfsmount *mnt)
 634 {
 635         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 636 }
 637
 638 static struct file_system_type fuse_fs_type = {
 639         .owner          = THIS_MODULE,
 640         .name           = "fuse",
 641         .fs_flags       = FS_HAS_SUBTYPE,
 642         .get_sb         = fuse_get_sb,
 643         .kill_sb        = kill_anon_super,
 644 };
 645
 646 #ifdef CONFIG_BLOCK
 647 static int fuse_get_sb_blk(struct file_system_type *fs_type,
 648                            int flags, const char *dev_name,
 649                            void *raw_data, struct vfsmount *mnt)
 650 {
 651         return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
 652                            mnt);
 653 }
 654
 655 static struct file_system_type fuseblk_fs_type = {
 656         .owner          = THIS_MODULE,
 657         .name           = "fuseblk",
 658         .get_sb         = fuse_get_sb_blk,
 659         .kill_sb        = kill_block_super,
 660         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
 661 };
 662
 663 static inline int register_fuseblk(void)
 664 {
 665         return register_filesystem(&fuseblk_fs_type);
 666 }
 667
 668 static inline void unregister_fuseblk(void)
 669 {
 670         unregister_filesystem(&fuseblk_fs_type);
 671 }
 672 #else
 673 static inline int register_fuseblk(void)
 674 {
 675         return 0;
 676 }
 677
 678 static inline void unregister_fuseblk(void)
 679 {
 680 }
 681 #endif
 682
 683 static decl_subsys(fuse, NULL, NULL);
 684 static decl_subsys(connections, NULL, NULL);
 685
 686 static void fuse_inode_init_once(void *foo, struct kmem_cache *cachep,
 687                                  unsigned long flags)
 688 {
 689         struct inode * inode = foo;
 690
 691         inode_init_once(inode);
 692 }
 693
 694 static int __init fuse_fs_init(void)
 695 {
 696         int err;
 697
 698         err = register_filesystem(&fuse_fs_type);
 699         if (err)
 700                 goto out;
 701
 702         err = register_fuseblk();
 703         if (err)
 704                 goto out_unreg;
 705
 706         fuse_inode_cachep = kmem_cache_create("fuse_inode",
 707                                               sizeof(struct fuse_inode),
 708                                               0, SLAB_HWCACHE_ALIGN,
 709                                               fuse_inode_init_once);
 710         err = -ENOMEM;
 711         if (!fuse_inode_cachep)
 712                 goto out_unreg2;
 713
 714         return 0;
 715
 716  out_unreg2:
 717         unregister_fuseblk();
 718  out_unreg:
 719         unregister_filesystem(&fuse_fs_type);
 720  out:
 721         return err;
 722 }
 723
 724 static void fuse_fs_cleanup(void)
 725 {
 726         unregister_filesystem(&fuse_fs_type);
 727         unregister_fuseblk();
 728         kmem_cache_destroy(fuse_inode_cachep);
 729 }
 730
 731 static int fuse_sysfs_init(void)
 732 {
 733         int err;
 734
 735         kobj_set_kset_s(&fuse_subsys, fs_subsys);
 736         err = subsystem_register(&fuse_subsys);
 737         if (err)
 738                 goto out_err;
 739
 740         kobj_set_kset_s(&connections_subsys, fuse_subsys);
 741         err = subsystem_register(&connections_subsys);
 742         if (err)
 743                 goto out_fuse_unregister;
 744
 745         return 0;
 746
 747  out_fuse_unregister:
 748         subsystem_unregister(&fuse_subsys);
 749  out_err:
 750         return err;
 751 }
 752
 753 static void fuse_sysfs_cleanup(void)
 754 {
 755         subsystem_unregister(&connections_subsys);
 756         subsystem_unregister(&fuse_subsys);
 757 }
 758
 759 static int __init fuse_init(void)
 760 {
 761         int res;
 762
 763         printk("fuse init (API version %i.%i)\n",
 764                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 765
 766         INIT_LIST_HEAD(&fuse_conn_list);
 767         res = fuse_fs_init();
 768         if (res)
 769                 goto err;
 770
 771         res = fuse_dev_init();
 772         if (res)
 773                 goto err_fs_cleanup;
 774
 775         res = fuse_sysfs_init();
 776         if (res)
 777                 goto err_dev_cleanup;
 778
 779         res = fuse_ctl_init();
 780         if (res)
 781                 goto err_sysfs_cleanup;
 782
 783         return 0;
 784
 785  err_sysfs_cleanup:
 786         fuse_sysfs_cleanup();
 787  err_dev_cleanup:
 788         fuse_dev_cleanup();
 789  err_fs_cleanup:
 790         fuse_fs_cleanup();
 791  err:
 792         return res;
 793 }
 794
 795 static void __exit fuse_exit(void)
 796 {
 797         printk(KERN_DEBUG "fuse exit\n");
 798
 799         fuse_ctl_cleanup();
 800         fuse_sysfs_cleanup();
 801         fuse_fs_cleanup();
 802         fuse_dev_cleanup();
 803 }
 804
 805 module_init(fuse_init);
 806 module_exit(fuse_exit);