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_inode_pages(inode->i_mapping);
 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                         d->rootmode = value;
 334                         d->rootmode_present = 1;
 335                         break;
 336
 337                 case OPT_USER_ID:
 338                         if (match_int(&args[0], &value))
 339                                 return 0;
 340                         d->user_id = value;
 341                         d->user_id_present = 1;
 342                         break;
 343
 344                 case OPT_GROUP_ID:
 345                         if (match_int(&args[0], &value))
 346                                 return 0;
 347                         d->group_id = value;
 348                         d->group_id_present = 1;
 349                         break;
 350
 351                 case OPT_DEFAULT_PERMISSIONS:
 352                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 353                         break;
 354
 355                 case OPT_ALLOW_OTHER:
 356                         d->flags |= FUSE_ALLOW_OTHER;
 357                         break;
 358
 359                 case OPT_MAX_READ:
 360                         if (match_int(&args[0], &value))
 361                                 return 0;
 362                         d->max_read = value;
 363                         break;
 364
 365                 case OPT_BLKSIZE:
 366                         if (!is_bdev || match_int(&args[0], &value))
 367                                 return 0;
 368                         d->blksize = value;
 369                         break;
 370
 371                 default:
 372                         return 0;
 373                 }
 374         }
 375
 376         if (!d->fd_present || !d->rootmode_present ||
 377             !d->user_id_present || !d->group_id_present)
 378                 return 0;
 379
 380         return 1;
 381 }
 382
 383 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 384 {
 385         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 386
 387         seq_printf(m, ",user_id=%u", fc->user_id);
 388         seq_printf(m, ",group_id=%u", fc->group_id);
 389         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 390                 seq_puts(m, ",default_permissions");
 391         if (fc->flags & FUSE_ALLOW_OTHER)
 392                 seq_puts(m, ",allow_other");
 393         if (fc->max_read != ~0)
 394                 seq_printf(m, ",max_read=%u", fc->max_read);
 395         return 0;
 396 }
 397
 398 static struct fuse_conn *new_conn(void)
 399 {
 400         struct fuse_conn *fc;
 401
 402         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 403         if (fc) {
 404                 spin_lock_init(&fc->lock);
 405                 mutex_init(&fc->inst_mutex);
 406                 atomic_set(&fc->count, 1);
 407                 init_waitqueue_head(&fc->waitq);
 408                 init_waitqueue_head(&fc->blocked_waitq);
 409                 INIT_LIST_HEAD(&fc->pending);
 410                 INIT_LIST_HEAD(&fc->processing);
 411                 INIT_LIST_HEAD(&fc->io);
 412                 INIT_LIST_HEAD(&fc->interrupts);
 413                 atomic_set(&fc->num_waiting, 0);
 414                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 415                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 416                 fc->reqctr = 0;
 417                 fc->blocked = 1;
 418                 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 419         }
 420         return fc;
 421 }
 422
 423 void fuse_conn_put(struct fuse_conn *fc)
 424 {
 425         if (atomic_dec_and_test(&fc->count)) {
 426                 if (fc->destroy_req)
 427                         fuse_request_free(fc->destroy_req);
 428                 mutex_destroy(&fc->inst_mutex);
 429                 kfree(fc);
 430         }
 431 }
 432
 433 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 434 {
 435         atomic_inc(&fc->count);
 436         return fc;
 437 }
 438
 439 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 440 {
 441         struct fuse_attr attr;
 442         memset(&attr, 0, sizeof(attr));
 443
 444         attr.mode = mode;
 445         attr.ino = FUSE_ROOT_ID;
 446         return fuse_iget(sb, 1, 0, &attr);
 447 }
 448
 449 static struct super_operations fuse_super_operations = {
 450         .alloc_inode    = fuse_alloc_inode,
 451         .destroy_inode  = fuse_destroy_inode,
 452         .read_inode     = fuse_read_inode,
 453         .clear_inode    = fuse_clear_inode,
 454         .remount_fs     = fuse_remount_fs,
 455         .put_super      = fuse_put_super,
 456         .umount_begin   = fuse_umount_begin,
 457         .statfs         = fuse_statfs,
 458         .show_options   = fuse_show_options,
 459 };
 460
 461 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 462 {
 463         struct fuse_init_out *arg = &req->misc.init_out;
 464
 465         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 466                 fc->conn_error = 1;
 467         else {
 468                 unsigned long ra_pages;
 469
 470                 if (arg->minor >= 6) {
 471                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 472                         if (arg->flags & FUSE_ASYNC_READ)
 473                                 fc->async_read = 1;
 474                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 475                                 fc->no_lock = 1;
 476                 } else {
 477                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 478                         fc->no_lock = 1;
 479                 }
 480
 481                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 482                 fc->minor = arg->minor;
 483                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 484                 fc->conn_init = 1;
 485         }
 486         fuse_put_request(fc, req);
 487         fc->blocked = 0;
 488         wake_up_all(&fc->blocked_waitq);
 489 }
 490
 491 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 492 {
 493         struct fuse_init_in *arg = &req->misc.init_in;
 494
 495         arg->major = FUSE_KERNEL_VERSION;
 496         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 497         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 498         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
 499         req->in.h.opcode = FUSE_INIT;
 500         req->in.numargs = 1;
 501         req->in.args[0].size = sizeof(*arg);
 502         req->in.args[0].value = arg;
 503         req->out.numargs = 1;
 504         /* Variable length arguement used for backward compatibility
 505            with interface version < 7.5.  Rest of init_out is zeroed
 506            by do_get_request(), so a short reply is not a problem */
 507         req->out.argvar = 1;
 508         req->out.args[0].size = sizeof(struct fuse_init_out);
 509         req->out.args[0].value = &req->misc.init_out;
 510         req->end = process_init_reply;
 511         request_send_background(fc, req);
 512 }
 513
 514 static u64 conn_id(void)
 515 {
 516         static u64 ctr = 1;
 517         return ctr++;
 518 }
 519
 520 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 521 {
 522         struct fuse_conn *fc;
 523         struct inode *root;
 524         struct fuse_mount_data d;
 525         struct file *file;
 526         struct dentry *root_dentry;
 527         struct fuse_req *init_req;
 528         int err;
 529         int is_bdev = sb->s_bdev != NULL;
 530
 531         if (sb->s_flags & MS_MANDLOCK)
 532                 return -EINVAL;
 533
 534         if (!parse_fuse_opt((char *) data, &d, is_bdev))
 535                 return -EINVAL;
 536
 537         if (is_bdev) {
 538 #ifdef CONFIG_BLOCK
 539                 if (!sb_set_blocksize(sb, d.blksize))
 540                         return -EINVAL;
 541 #endif
 542         } else {
 543                 sb->s_blocksize = PAGE_CACHE_SIZE;
 544                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 545         }
 546         sb->s_magic = FUSE_SUPER_MAGIC;
 547         sb->s_op = &fuse_super_operations;
 548         sb->s_maxbytes = MAX_LFS_FILESIZE;
 549
 550         file = fget(d.fd);
 551         if (!file)
 552                 return -EINVAL;
 553
 554         if (file->f_op != &fuse_dev_operations)
 555                 return -EINVAL;
 556
 557         fc = new_conn();
 558         if (!fc)
 559                 return -ENOMEM;
 560
 561         fc->flags = d.flags;
 562         fc->user_id = d.user_id;
 563         fc->group_id = d.group_id;
 564         fc->max_read = d.max_read;
 565
 566         /* Used by get_root_inode() */
 567         sb->s_fs_info = fc;
 568
 569         err = -ENOMEM;
 570         root = get_root_inode(sb, d.rootmode);
 571         if (!root)
 572                 goto err;
 573
 574         root_dentry = d_alloc_root(root);
 575         if (!root_dentry) {
 576                 iput(root);
 577                 goto err;
 578         }
 579
 580         init_req = fuse_request_alloc();
 581         if (!init_req)
 582                 goto err_put_root;
 583
 584         if (is_bdev) {
 585                 fc->destroy_req = fuse_request_alloc();
 586                 if (!fc->destroy_req)
 587                         goto err_put_root;
 588         }
 589
 590         mutex_lock(&fuse_mutex);
 591         err = -EINVAL;
 592         if (file->private_data)
 593                 goto err_unlock;
 594
 595         fc->id = conn_id();
 596         err = fuse_ctl_add_conn(fc);
 597         if (err)
 598                 goto err_unlock;
 599
 600         list_add_tail(&fc->entry, &fuse_conn_list);
 601         sb->s_root = root_dentry;
 602         fc->connected = 1;
 603         file->private_data = fuse_conn_get(fc);
 604         mutex_unlock(&fuse_mutex);
 605         /*
 606          * atomic_dec_and_test() in fput() provides the necessary
 607          * memory barrier for file->private_data to be visible on all
 608          * CPUs after this
 609          */
 610         fput(file);
 611
 612         fuse_send_init(fc, init_req);
 613
 614         return 0;
 615
 616  err_unlock:
 617         mutex_unlock(&fuse_mutex);
 618         fuse_request_free(init_req);
 619  err_put_root:
 620         dput(root_dentry);
 621  err:
 622         fput(file);
 623         fuse_conn_put(fc);
 624         return err;
 625 }
 626
 627 static int fuse_get_sb(struct file_system_type *fs_type,
 628                        int flags, const char *dev_name,
 629                        void *raw_data, struct vfsmount *mnt)
 630 {
 631         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 632 }
 633
 634 static struct file_system_type fuse_fs_type = {
 635         .owner          = THIS_MODULE,
 636         .name           = "fuse",
 637         .get_sb         = fuse_get_sb,
 638         .kill_sb        = kill_anon_super,
 639 };
 640
 641 #ifdef CONFIG_BLOCK
 642 static int fuse_get_sb_blk(struct file_system_type *fs_type,
 643                            int flags, const char *dev_name,
 644                            void *raw_data, struct vfsmount *mnt)
 645 {
 646         return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
 647                            mnt);
 648 }
 649
 650 static struct file_system_type fuseblk_fs_type = {
 651         .owner          = THIS_MODULE,
 652         .name           = "fuseblk",
 653         .get_sb         = fuse_get_sb_blk,
 654         .kill_sb        = kill_block_super,
 655         .fs_flags       = FS_REQUIRES_DEV,
 656 };
 657
 658 static inline int register_fuseblk(void)
 659 {
 660         return register_filesystem(&fuseblk_fs_type);
 661 }
 662
 663 static inline void unregister_fuseblk(void)
 664 {
 665         unregister_filesystem(&fuseblk_fs_type);
 666 }
 667 #else
 668 static inline int register_fuseblk(void)
 669 {
 670         return 0;
 671 }
 672
 673 static inline void unregister_fuseblk(void)
 674 {
 675 }
 676 #endif
 677
 678 static decl_subsys(fuse, NULL, NULL);
 679 static decl_subsys(connections, NULL, NULL);
 680
 681 static void fuse_inode_init_once(void *foo, struct kmem_cache *cachep,
 682                                  unsigned long flags)
 683 {
 684         struct inode * inode = foo;
 685
 686         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 687             SLAB_CTOR_CONSTRUCTOR)
 688                 inode_init_once(inode);
 689 }
 690
 691 static int __init fuse_fs_init(void)
 692 {
 693         int err;
 694
 695         err = register_filesystem(&fuse_fs_type);
 696         if (err)
 697                 goto out;
 698
 699         err = register_fuseblk();
 700         if (err)
 701                 goto out_unreg;
 702
 703         fuse_inode_cachep = kmem_cache_create("fuse_inode",
 704                                               sizeof(struct fuse_inode),
 705                                               0, SLAB_HWCACHE_ALIGN,
 706                                               fuse_inode_init_once, NULL);
 707         err = -ENOMEM;
 708         if (!fuse_inode_cachep)
 709                 goto out_unreg2;
 710
 711         return 0;
 712
 713  out_unreg2:
 714         unregister_fuseblk();
 715  out_unreg:
 716         unregister_filesystem(&fuse_fs_type);
 717  out:
 718         return err;
 719 }
 720
 721 static void fuse_fs_cleanup(void)
 722 {
 723         unregister_filesystem(&fuse_fs_type);
 724         unregister_fuseblk();
 725         kmem_cache_destroy(fuse_inode_cachep);
 726 }
 727
 728 static int fuse_sysfs_init(void)
 729 {
 730         int err;
 731
 732         kset_set_kset_s(&fuse_subsys, fs_subsys);
 733         err = subsystem_register(&fuse_subsys);
 734         if (err)
 735                 goto out_err;
 736
 737         kset_set_kset_s(&connections_subsys, fuse_subsys);
 738         err = subsystem_register(&connections_subsys);
 739         if (err)
 740                 goto out_fuse_unregister;
 741
 742         return 0;
 743
 744  out_fuse_unregister:
 745         subsystem_unregister(&fuse_subsys);
 746  out_err:
 747         return err;
 748 }
 749
 750 static void fuse_sysfs_cleanup(void)
 751 {
 752         subsystem_unregister(&connections_subsys);
 753         subsystem_unregister(&fuse_subsys);
 754 }
 755
 756 static int __init fuse_init(void)
 757 {
 758         int res;
 759
 760         printk("fuse init (API version %i.%i)\n",
 761                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 762
 763         INIT_LIST_HEAD(&fuse_conn_list);
 764         res = fuse_fs_init();
 765         if (res)
 766                 goto err;
 767
 768         res = fuse_dev_init();
 769         if (res)
 770                 goto err_fs_cleanup;
 771
 772         res = fuse_sysfs_init();
 773         if (res)
 774                 goto err_dev_cleanup;
 775
 776         res = fuse_ctl_init();
 777         if (res)
 778                 goto err_sysfs_cleanup;
 779
 780         return 0;
 781
 782  err_sysfs_cleanup:
 783         fuse_sysfs_cleanup();
 784  err_dev_cleanup:
 785         fuse_dev_cleanup();
 786  err_fs_cleanup:
 787         fuse_fs_cleanup();
 788  err:
 789         return res;
 790 }
 791
 792 static void __exit fuse_exit(void)
 793 {
 794         printk(KERN_DEBUG "fuse exit\n");
 795
 796         fuse_ctl_cleanup();
 797         fuse_sysfs_cleanup();
 798         fuse_fs_cleanup();
 799         fuse_dev_cleanup();
 800 }
 801
 802 module_init(fuse_init);
 803 module_exit(fuse_exit);