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         int err;
 405
 406         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 407         if (fc) {
 408                 spin_lock_init(&fc->lock);
 409                 mutex_init(&fc->inst_mutex);
 410                 atomic_set(&fc->count, 1);
 411                 init_waitqueue_head(&fc->waitq);
 412                 init_waitqueue_head(&fc->blocked_waitq);
 413                 INIT_LIST_HEAD(&fc->pending);
 414                 INIT_LIST_HEAD(&fc->processing);
 415                 INIT_LIST_HEAD(&fc->io);
 416                 INIT_LIST_HEAD(&fc->interrupts);
 417                 atomic_set(&fc->num_waiting, 0);
 418                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 419                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 420                 err = bdi_init(&fc->bdi);
 421                 if (err) {
 422                         kfree(fc);
 423                         fc = NULL;
 424                         goto out;
 425                 }
 426                 fc->reqctr = 0;
 427                 fc->blocked = 1;
 428                 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 429         }
 430 out:
 431         return fc;
 432 }
 433
 434 void fuse_conn_put(struct fuse_conn *fc)
 435 {
 436         if (atomic_dec_and_test(&fc->count)) {
 437                 if (fc->destroy_req)
 438                         fuse_request_free(fc->destroy_req);
 439                 mutex_destroy(&fc->inst_mutex);
 440                 bdi_destroy(&fc->bdi);
 441                 kfree(fc);
 442         }
 443 }
 444
 445 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 446 {
 447         atomic_inc(&fc->count);
 448         return fc;
 449 }
 450
 451 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 452 {
 453         struct fuse_attr attr;
 454         memset(&attr, 0, sizeof(attr));
 455
 456         attr.mode = mode;
 457         attr.ino = FUSE_ROOT_ID;
 458         return fuse_iget(sb, 1, 0, &attr);
 459 }
 460
 461 static const struct super_operations fuse_super_operations = {
 462         .alloc_inode    = fuse_alloc_inode,
 463         .destroy_inode  = fuse_destroy_inode,
 464         .read_inode     = fuse_read_inode,
 465         .clear_inode    = fuse_clear_inode,
 466         .drop_inode     = generic_delete_inode,
 467         .remount_fs     = fuse_remount_fs,
 468         .put_super      = fuse_put_super,
 469         .umount_begin   = fuse_umount_begin,
 470         .statfs         = fuse_statfs,
 471         .show_options   = fuse_show_options,
 472 };
 473
 474 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 475 {
 476         struct fuse_init_out *arg = &req->misc.init_out;
 477
 478         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 479                 fc->conn_error = 1;
 480         else {
 481                 unsigned long ra_pages;
 482
 483                 if (arg->minor >= 6) {
 484                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 485                         if (arg->flags & FUSE_ASYNC_READ)
 486                                 fc->async_read = 1;
 487                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 488                                 fc->no_lock = 1;
 489                 } else {
 490                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 491                         fc->no_lock = 1;
 492                 }
 493
 494                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 495                 fc->minor = arg->minor;
 496                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 497                 fc->conn_init = 1;
 498         }
 499         fuse_put_request(fc, req);
 500         fc->blocked = 0;
 501         wake_up_all(&fc->blocked_waitq);
 502 }
 503
 504 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 505 {
 506         struct fuse_init_in *arg = &req->misc.init_in;
 507
 508         arg->major = FUSE_KERNEL_VERSION;
 509         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 510         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 511         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
 512         req->in.h.opcode = FUSE_INIT;
 513         req->in.numargs = 1;
 514         req->in.args[0].size = sizeof(*arg);
 515         req->in.args[0].value = arg;
 516         req->out.numargs = 1;
 517         /* Variable length arguement used for backward compatibility
 518            with interface version < 7.5.  Rest of init_out is zeroed
 519            by do_get_request(), so a short reply is not a problem */
 520         req->out.argvar = 1;
 521         req->out.args[0].size = sizeof(struct fuse_init_out);
 522         req->out.args[0].value = &req->misc.init_out;
 523         req->end = process_init_reply;
 524         request_send_background(fc, req);
 525 }
 526
 527 static u64 conn_id(void)
 528 {
 529         static u64 ctr = 1;
 530         return ctr++;
 531 }
 532
 533 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 534 {
 535         struct fuse_conn *fc;
 536         struct inode *root;
 537         struct fuse_mount_data d;
 538         struct file *file;
 539         struct dentry *root_dentry;
 540         struct fuse_req *init_req;
 541         int err;
 542         int is_bdev = sb->s_bdev != NULL;
 543
 544         if (sb->s_flags & MS_MANDLOCK)
 545                 return -EINVAL;
 546
 547         if (!parse_fuse_opt((char *) data, &d, is_bdev))
 548                 return -EINVAL;
 549
 550         if (is_bdev) {
 551 #ifdef CONFIG_BLOCK
 552                 if (!sb_set_blocksize(sb, d.blksize))
 553                         return -EINVAL;
 554 #endif
 555         } else {
 556                 sb->s_blocksize = PAGE_CACHE_SIZE;
 557                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 558         }
 559         sb->s_magic = FUSE_SUPER_MAGIC;
 560         sb->s_op = &fuse_super_operations;
 561         sb->s_maxbytes = MAX_LFS_FILESIZE;
 562
 563         file = fget(d.fd);
 564         if (!file)
 565                 return -EINVAL;
 566
 567         if (file->f_op != &fuse_dev_operations)
 568                 return -EINVAL;
 569
 570         fc = new_conn();
 571         if (!fc)
 572                 return -ENOMEM;
 573
 574         fc->flags = d.flags;
 575         fc->user_id = d.user_id;
 576         fc->group_id = d.group_id;
 577         fc->max_read = d.max_read;
 578
 579         /* Used by get_root_inode() */
 580         sb->s_fs_info = fc;
 581
 582         err = -ENOMEM;
 583         root = get_root_inode(sb, d.rootmode);
 584         if (!root)
 585                 goto err;
 586
 587         root_dentry = d_alloc_root(root);
 588         if (!root_dentry) {
 589                 iput(root);
 590                 goto err;
 591         }
 592
 593         init_req = fuse_request_alloc();
 594         if (!init_req)
 595                 goto err_put_root;
 596
 597         if (is_bdev) {
 598                 fc->destroy_req = fuse_request_alloc();
 599                 if (!fc->destroy_req)
 600                         goto err_put_root;
 601         }
 602
 603         mutex_lock(&fuse_mutex);
 604         err = -EINVAL;
 605         if (file->private_data)
 606                 goto err_unlock;
 607
 608         fc->id = conn_id();
 609         err = fuse_ctl_add_conn(fc);
 610         if (err)
 611                 goto err_unlock;
 612
 613         list_add_tail(&fc->entry, &fuse_conn_list);
 614         sb->s_root = root_dentry;
 615         fc->connected = 1;
 616         file->private_data = fuse_conn_get(fc);
 617         mutex_unlock(&fuse_mutex);
 618         /*
 619          * atomic_dec_and_test() in fput() provides the necessary
 620          * memory barrier for file->private_data to be visible on all
 621          * CPUs after this
 622          */
 623         fput(file);
 624
 625         fuse_send_init(fc, init_req);
 626
 627         return 0;
 628
 629  err_unlock:
 630         mutex_unlock(&fuse_mutex);
 631         fuse_request_free(init_req);
 632  err_put_root:
 633         dput(root_dentry);
 634  err:
 635         fput(file);
 636         fuse_conn_put(fc);
 637         return err;
 638 }
 639
 640 static int fuse_get_sb(struct file_system_type *fs_type,
 641                        int flags, const char *dev_name,
 642                        void *raw_data, struct vfsmount *mnt)
 643 {
 644         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 645 }
 646
 647 static struct file_system_type fuse_fs_type = {
 648         .owner          = THIS_MODULE,
 649         .name           = "fuse",
 650         .fs_flags       = FS_HAS_SUBTYPE,
 651         .get_sb         = fuse_get_sb,
 652         .kill_sb        = kill_anon_super,
 653 };
 654
 655 #ifdef CONFIG_BLOCK
 656 static int fuse_get_sb_blk(struct file_system_type *fs_type,
 657                            int flags, const char *dev_name,
 658                            void *raw_data, struct vfsmount *mnt)
 659 {
 660         return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
 661                            mnt);
 662 }
 663
 664 static struct file_system_type fuseblk_fs_type = {
 665         .owner          = THIS_MODULE,
 666         .name           = "fuseblk",
 667         .get_sb         = fuse_get_sb_blk,
 668         .kill_sb        = kill_block_super,
 669         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
 670 };
 671
 672 static inline int register_fuseblk(void)
 673 {
 674         return register_filesystem(&fuseblk_fs_type);
 675 }
 676
 677 static inline void unregister_fuseblk(void)
 678 {
 679         unregister_filesystem(&fuseblk_fs_type);
 680 }
 681 #else
 682 static inline int register_fuseblk(void)
 683 {
 684         return 0;
 685 }
 686
 687 static inline void unregister_fuseblk(void)
 688 {
 689 }
 690 #endif
 691
 692 static decl_subsys(fuse, NULL, NULL);
 693 static decl_subsys(connections, NULL, NULL);
 694
 695 static void fuse_inode_init_once(struct kmem_cache *cachep, void *foo)
 696 {
 697         struct inode * inode = foo;
 698
 699         inode_init_once(inode);
 700 }
 701
 702 static int __init fuse_fs_init(void)
 703 {
 704         int err;
 705
 706         err = register_filesystem(&fuse_fs_type);
 707         if (err)
 708                 goto out;
 709
 710         err = register_fuseblk();
 711         if (err)
 712                 goto out_unreg;
 713
 714         fuse_inode_cachep = kmem_cache_create("fuse_inode",
 715                                               sizeof(struct fuse_inode),
 716                                               0, SLAB_HWCACHE_ALIGN,
 717                                               fuse_inode_init_once);
 718         err = -ENOMEM;
 719         if (!fuse_inode_cachep)
 720                 goto out_unreg2;
 721
 722         return 0;
 723
 724  out_unreg2:
 725         unregister_fuseblk();
 726  out_unreg:
 727         unregister_filesystem(&fuse_fs_type);
 728  out:
 729         return err;
 730 }
 731
 732 static void fuse_fs_cleanup(void)
 733 {
 734         unregister_filesystem(&fuse_fs_type);
 735         unregister_fuseblk();
 736         kmem_cache_destroy(fuse_inode_cachep);
 737 }
 738
 739 static int fuse_sysfs_init(void)
 740 {
 741         int err;
 742
 743         kobj_set_kset_s(&fuse_subsys, fs_subsys);
 744         err = subsystem_register(&fuse_subsys);
 745         if (err)
 746                 goto out_err;
 747
 748         kobj_set_kset_s(&connections_subsys, fuse_subsys);
 749         err = subsystem_register(&connections_subsys);
 750         if (err)
 751                 goto out_fuse_unregister;
 752
 753         return 0;
 754
 755  out_fuse_unregister:
 756         subsystem_unregister(&fuse_subsys);
 757  out_err:
 758         return err;
 759 }
 760
 761 static void fuse_sysfs_cleanup(void)
 762 {
 763         subsystem_unregister(&connections_subsys);
 764         subsystem_unregister(&fuse_subsys);
 765 }
 766
 767 static int __init fuse_init(void)
 768 {
 769         int res;
 770
 771         printk("fuse init (API version %i.%i)\n",
 772                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 773
 774         INIT_LIST_HEAD(&fuse_conn_list);
 775         res = fuse_fs_init();
 776         if (res)
 777                 goto err;
 778
 779         res = fuse_dev_init();
 780         if (res)
 781                 goto err_fs_cleanup;
 782
 783         res = fuse_sysfs_init();
 784         if (res)
 785                 goto err_dev_cleanup;
 786
 787         res = fuse_ctl_init();
 788         if (res)
 789                 goto err_sysfs_cleanup;
 790
 791         return 0;
 792
 793  err_sysfs_cleanup:
 794         fuse_sysfs_cleanup();
 795  err_dev_cleanup:
 796         fuse_dev_cleanup();
 797  err_fs_cleanup:
 798         fuse_fs_cleanup();
 799  err:
 800         return res;
 801 }
 802
 803 static void __exit fuse_exit(void)
 804 {
 805         printk(KERN_DEBUG "fuse exit\n");
 806
 807         fuse_ctl_cleanup();
 808         fuse_sysfs_cleanup();
 809         fuse_fs_cleanup();
 810         fuse_dev_cleanup();
 811 }
 812
 813 module_init(fuse_init);
 814 module_exit(fuse_exit);