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