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/mount.h>
  15 #include <linux/seq_file.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/parser.h>
  19 #include <linux/statfs.h>
  20
  21 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
  22 MODULE_DESCRIPTION("Filesystem in Userspace");
  23 MODULE_LICENSE("GPL");
  24
  25 static kmem_cache_t *fuse_inode_cachep;
  26 static struct subsystem connections_subsys;
  27
  28 struct fuse_conn_attr {
  29         struct attribute attr;
  30         ssize_t (*show)(struct fuse_conn *, char *);
  31         ssize_t (*store)(struct fuse_conn *, const char *, size_t);
  32 };
  33
  34 #define FUSE_SUPER_MAGIC 0x65735546
  35
  36 struct fuse_mount_data {
  37         int fd;
  38         unsigned rootmode;
  39         unsigned user_id;
  40         unsigned group_id;
  41         unsigned fd_present : 1;
  42         unsigned rootmode_present : 1;
  43         unsigned user_id_present : 1;
  44         unsigned group_id_present : 1;
  45         unsigned flags;
  46         unsigned max_read;
  47 };
  48
  49 static struct inode *fuse_alloc_inode(struct super_block *sb)
  50 {
  51         struct inode *inode;
  52         struct fuse_inode *fi;
  53
  54         inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
  55         if (!inode)
  56                 return NULL;
  57
  58         fi = get_fuse_inode(inode);
  59         fi->i_time = jiffies - 1;
  60         fi->nodeid = 0;
  61         fi->nlookup = 0;
  62         fi->forget_req = fuse_request_alloc();
  63         if (!fi->forget_req) {
  64                 kmem_cache_free(fuse_inode_cachep, inode);
  65                 return NULL;
  66         }
  67
  68         return inode;
  69 }
  70
  71 static void fuse_destroy_inode(struct inode *inode)
  72 {
  73         struct fuse_inode *fi = get_fuse_inode(inode);
  74         if (fi->forget_req)
  75                 fuse_request_free(fi->forget_req);
  76         kmem_cache_free(fuse_inode_cachep, inode);
  77 }
  78
  79 static void fuse_read_inode(struct inode *inode)
  80 {
  81         /* No op */
  82 }
  83
  84 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
  85                       unsigned long nodeid, u64 nlookup)
  86 {
  87         struct fuse_forget_in *inarg = &req->misc.forget_in;
  88         inarg->nlookup = nlookup;
  89         req->in.h.opcode = FUSE_FORGET;
  90         req->in.h.nodeid = nodeid;
  91         req->in.numargs = 1;
  92         req->in.args[0].size = sizeof(struct fuse_forget_in);
  93         req->in.args[0].value = inarg;
  94         request_send_noreply(fc, req);
  95 }
  96
  97 static void fuse_clear_inode(struct inode *inode)
  98 {
  99         if (inode->i_sb->s_flags & MS_ACTIVE) {
 100                 struct fuse_conn *fc = get_fuse_conn(inode);
 101                 struct fuse_inode *fi = get_fuse_inode(inode);
 102                 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
 103                 fi->forget_req = NULL;
 104         }
 105 }
 106
 107 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
 108 {
 109         if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
 110                 invalidate_inode_pages(inode->i_mapping);
 111
 112         inode->i_ino     = attr->ino;
 113         inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
 114         inode->i_nlink   = attr->nlink;
 115         inode->i_uid     = attr->uid;
 116         inode->i_gid     = attr->gid;
 117         i_size_write(inode, attr->size);
 118         inode->i_blksize = PAGE_CACHE_SIZE;
 119         inode->i_blocks  = attr->blocks;
 120         inode->i_atime.tv_sec   = attr->atime;
 121         inode->i_atime.tv_nsec  = attr->atimensec;
 122         inode->i_mtime.tv_sec   = attr->mtime;
 123         inode->i_mtime.tv_nsec  = attr->mtimensec;
 124         inode->i_ctime.tv_sec   = attr->ctime;
 125         inode->i_ctime.tv_nsec  = attr->ctimensec;
 126 }
 127
 128 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 129 {
 130         inode->i_mode = attr->mode & S_IFMT;
 131         i_size_write(inode, attr->size);
 132         if (S_ISREG(inode->i_mode)) {
 133                 fuse_init_common(inode);
 134                 fuse_init_file_inode(inode);
 135         } else if (S_ISDIR(inode->i_mode))
 136                 fuse_init_dir(inode);
 137         else if (S_ISLNK(inode->i_mode))
 138                 fuse_init_symlink(inode);
 139         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 140                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 141                 fuse_init_common(inode);
 142                 init_special_inode(inode, inode->i_mode,
 143                                    new_decode_dev(attr->rdev));
 144         } else
 145                 BUG();
 146 }
 147
 148 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 149 {
 150         unsigned long nodeid = *(unsigned long *) _nodeidp;
 151         if (get_node_id(inode) == nodeid)
 152                 return 1;
 153         else
 154                 return 0;
 155 }
 156
 157 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 158 {
 159         unsigned long nodeid = *(unsigned long *) _nodeidp;
 160         get_fuse_inode(inode)->nodeid = nodeid;
 161         return 0;
 162 }
 163
 164 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 165                         int generation, struct fuse_attr *attr)
 166 {
 167         struct inode *inode;
 168         struct fuse_inode *fi;
 169         struct fuse_conn *fc = get_fuse_conn_super(sb);
 170         int retried = 0;
 171
 172  retry:
 173         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 174         if (!inode)
 175                 return NULL;
 176
 177         if ((inode->i_state & I_NEW)) {
 178                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
 179                 inode->i_generation = generation;
 180                 inode->i_data.backing_dev_info = &fc->bdi;
 181                 fuse_init_inode(inode, attr);
 182                 unlock_new_inode(inode);
 183         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 184                 BUG_ON(retried);
 185                 /* Inode has changed type, any I/O on the old should fail */
 186                 make_bad_inode(inode);
 187                 iput(inode);
 188                 retried = 1;
 189                 goto retry;
 190         }
 191
 192         fi = get_fuse_inode(inode);
 193         fi->nlookup ++;
 194         fuse_change_attributes(inode, attr);
 195         return inode;
 196 }
 197
 198 static void fuse_umount_begin(struct super_block *sb)
 199 {
 200         fuse_abort_conn(get_fuse_conn_super(sb));
 201 }
 202
 203 static void fuse_put_super(struct super_block *sb)
 204 {
 205         struct fuse_conn *fc = get_fuse_conn_super(sb);
 206
 207         spin_lock(&fc->lock);
 208         fc->connected = 0;
 209         while (!list_empty(&fc->background)) {
 210                 struct fuse_req *req = list_entry(fc->background.next,
 211                                                   struct fuse_req, bg_entry);
 212                 struct inode *inode = req->inode;
 213                 struct inode *inode2 = req->inode2;
 214
 215                 /* File would hold a reference to vfsmount */
 216                 BUG_ON(req->file);
 217                 req->inode = NULL;
 218                 req->inode2 = NULL;
 219                 fuse_remove_background(fc, req);
 220
 221                 spin_unlock(&fc->lock);
 222                 iput(inode);
 223                 iput(inode2);
 224                 spin_lock(&fc->lock);
 225         }
 226         spin_unlock(&fc->lock);
 227         /* Flush all readers on this fs */
 228         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 229         wake_up_all(&fc->waitq);
 230         kobject_del(&fc->kobj);
 231         kobject_put(&fc->kobj);
 232 }
 233
 234 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 235 {
 236         stbuf->f_type    = FUSE_SUPER_MAGIC;
 237         stbuf->f_bsize   = attr->bsize;
 238         stbuf->f_frsize  = attr->frsize;
 239         stbuf->f_blocks  = attr->blocks;
 240         stbuf->f_bfree   = attr->bfree;
 241         stbuf->f_bavail  = attr->bavail;
 242         stbuf->f_files   = attr->files;
 243         stbuf->f_ffree   = attr->ffree;
 244         stbuf->f_namelen = attr->namelen;
 245         /* fsid is left zero */
 246 }
 247
 248 static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
 249 {
 250         struct fuse_conn *fc = get_fuse_conn_super(sb);
 251         struct fuse_req *req;
 252         struct fuse_statfs_out outarg;
 253         int err;
 254
 255         req = fuse_get_req(fc);
 256         if (IS_ERR(req))
 257                 return PTR_ERR(req);
 258
 259         memset(&outarg, 0, sizeof(outarg));
 260         req->in.numargs = 0;
 261         req->in.h.opcode = FUSE_STATFS;
 262         req->out.numargs = 1;
 263         req->out.args[0].size =
 264                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 265         req->out.args[0].value = &outarg;
 266         request_send(fc, req);
 267         err = req->out.h.error;
 268         if (!err)
 269                 convert_fuse_statfs(buf, &outarg.st);
 270         fuse_put_request(fc, req);
 271         return err;
 272 }
 273
 274 enum {
 275         OPT_FD,
 276         OPT_ROOTMODE,
 277         OPT_USER_ID,
 278         OPT_GROUP_ID,
 279         OPT_DEFAULT_PERMISSIONS,
 280         OPT_ALLOW_OTHER,
 281         OPT_MAX_READ,
 282         OPT_ERR
 283 };
 284
 285 static match_table_t tokens = {
 286         {OPT_FD,                        "fd=%u"},
 287         {OPT_ROOTMODE,                  "rootmode=%o"},
 288         {OPT_USER_ID,                   "user_id=%u"},
 289         {OPT_GROUP_ID,                  "group_id=%u"},
 290         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 291         {OPT_ALLOW_OTHER,               "allow_other"},
 292         {OPT_MAX_READ,                  "max_read=%u"},
 293         {OPT_ERR,                       NULL}
 294 };
 295
 296 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
 297 {
 298         char *p;
 299         memset(d, 0, sizeof(struct fuse_mount_data));
 300         d->max_read = ~0;
 301
 302         while ((p = strsep(&opt, ",")) != NULL) {
 303                 int token;
 304                 int value;
 305                 substring_t args[MAX_OPT_ARGS];
 306                 if (!*p)
 307                         continue;
 308
 309                 token = match_token(p, tokens, args);
 310                 switch (token) {
 311                 case OPT_FD:
 312                         if (match_int(&args[0], &value))
 313                                 return 0;
 314                         d->fd = value;
 315                         d->fd_present = 1;
 316                         break;
 317
 318                 case OPT_ROOTMODE:
 319                         if (match_octal(&args[0], &value))
 320                                 return 0;
 321                         d->rootmode = value;
 322                         d->rootmode_present = 1;
 323                         break;
 324
 325                 case OPT_USER_ID:
 326                         if (match_int(&args[0], &value))
 327                                 return 0;
 328                         d->user_id = value;
 329                         d->user_id_present = 1;
 330                         break;
 331
 332                 case OPT_GROUP_ID:
 333                         if (match_int(&args[0], &value))
 334                                 return 0;
 335                         d->group_id = value;
 336                         d->group_id_present = 1;
 337                         break;
 338
 339                 case OPT_DEFAULT_PERMISSIONS:
 340                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 341                         break;
 342
 343                 case OPT_ALLOW_OTHER:
 344                         d->flags |= FUSE_ALLOW_OTHER;
 345                         break;
 346
 347                 case OPT_MAX_READ:
 348                         if (match_int(&args[0], &value))
 349                                 return 0;
 350                         d->max_read = value;
 351                         break;
 352
 353                 default:
 354                         return 0;
 355                 }
 356         }
 357
 358         if (!d->fd_present || !d->rootmode_present ||
 359             !d->user_id_present || !d->group_id_present)
 360                 return 0;
 361
 362         return 1;
 363 }
 364
 365 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 366 {
 367         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 368
 369         seq_printf(m, ",user_id=%u", fc->user_id);
 370         seq_printf(m, ",group_id=%u", fc->group_id);
 371         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 372                 seq_puts(m, ",default_permissions");
 373         if (fc->flags & FUSE_ALLOW_OTHER)
 374                 seq_puts(m, ",allow_other");
 375         if (fc->max_read != ~0)
 376                 seq_printf(m, ",max_read=%u", fc->max_read);
 377         return 0;
 378 }
 379
 380 static void fuse_conn_release(struct kobject *kobj)
 381 {
 382         kfree(get_fuse_conn_kobj(kobj));
 383 }
 384
 385 static struct fuse_conn *new_conn(void)
 386 {
 387         struct fuse_conn *fc;
 388
 389         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 390         if (fc) {
 391                 spin_lock_init(&fc->lock);
 392                 init_waitqueue_head(&fc->waitq);
 393                 init_waitqueue_head(&fc->blocked_waitq);
 394                 INIT_LIST_HEAD(&fc->pending);
 395                 INIT_LIST_HEAD(&fc->processing);
 396                 INIT_LIST_HEAD(&fc->io);
 397                 INIT_LIST_HEAD(&fc->background);
 398                 kobj_set_kset_s(fc, connections_subsys);
 399                 kobject_init(&fc->kobj);
 400                 atomic_set(&fc->num_waiting, 0);
 401                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 402                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 403                 fc->reqctr = 0;
 404                 fc->blocked = 1;
 405         }
 406         return fc;
 407 }
 408
 409 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 410 {
 411         struct fuse_attr attr;
 412         memset(&attr, 0, sizeof(attr));
 413
 414         attr.mode = mode;
 415         attr.ino = FUSE_ROOT_ID;
 416         return fuse_iget(sb, 1, 0, &attr);
 417 }
 418
 419 static struct super_operations fuse_super_operations = {
 420         .alloc_inode    = fuse_alloc_inode,
 421         .destroy_inode  = fuse_destroy_inode,
 422         .read_inode     = fuse_read_inode,
 423         .clear_inode    = fuse_clear_inode,
 424         .put_super      = fuse_put_super,
 425         .umount_begin   = fuse_umount_begin,
 426         .statfs         = fuse_statfs,
 427         .show_options   = fuse_show_options,
 428 };
 429
 430 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 431 {
 432         struct fuse_init_out *arg = &req->misc.init_out;
 433
 434         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 435                 fc->conn_error = 1;
 436         else {
 437                 unsigned long ra_pages;
 438
 439                 if (arg->minor >= 6) {
 440                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 441                         if (arg->flags & FUSE_ASYNC_READ)
 442                                 fc->async_read = 1;
 443                 } else
 444                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 445
 446                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 447                 fc->minor = arg->minor;
 448                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 449         }
 450         fuse_put_request(fc, req);
 451         fc->blocked = 0;
 452         wake_up_all(&fc->blocked_waitq);
 453 }
 454
 455 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 456 {
 457         struct fuse_init_in *arg = &req->misc.init_in;
 458
 459         arg->major = FUSE_KERNEL_VERSION;
 460         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 461         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 462         arg->flags |= FUSE_ASYNC_READ;
 463         req->in.h.opcode = FUSE_INIT;
 464         req->in.numargs = 1;
 465         req->in.args[0].size = sizeof(*arg);
 466         req->in.args[0].value = arg;
 467         req->out.numargs = 1;
 468         /* Variable length arguement used for backward compatibility
 469            with interface version < 7.5.  Rest of init_out is zeroed
 470            by do_get_request(), so a short reply is not a problem */
 471         req->out.argvar = 1;
 472         req->out.args[0].size = sizeof(struct fuse_init_out);
 473         req->out.args[0].value = &req->misc.init_out;
 474         req->end = process_init_reply;
 475         request_send_background(fc, req);
 476 }
 477
 478 static unsigned long long conn_id(void)
 479 {
 480         /* BKL is held for ->get_sb() */
 481         static unsigned long long ctr = 1;
 482         return ctr++;
 483 }
 484
 485 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 486 {
 487         struct fuse_conn *fc;
 488         struct inode *root;
 489         struct fuse_mount_data d;
 490         struct file *file;
 491         struct dentry *root_dentry;
 492         struct fuse_req *init_req;
 493         int err;
 494
 495         if (!parse_fuse_opt((char *) data, &d))
 496                 return -EINVAL;
 497
 498         sb->s_blocksize = PAGE_CACHE_SIZE;
 499         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 500         sb->s_magic = FUSE_SUPER_MAGIC;
 501         sb->s_op = &fuse_super_operations;
 502         sb->s_maxbytes = MAX_LFS_FILESIZE;
 503
 504         file = fget(d.fd);
 505         if (!file)
 506                 return -EINVAL;
 507
 508         if (file->f_op != &fuse_dev_operations)
 509                 return -EINVAL;
 510
 511         /* Setting file->private_data can't race with other mount()
 512            instances, since BKL is held for ->get_sb() */
 513         if (file->private_data)
 514                 return -EINVAL;
 515
 516         fc = new_conn();
 517         if (!fc)
 518                 return -ENOMEM;
 519
 520         fc->flags = d.flags;
 521         fc->user_id = d.user_id;
 522         fc->group_id = d.group_id;
 523         fc->max_read = d.max_read;
 524
 525         /* Used by get_root_inode() */
 526         sb->s_fs_info = fc;
 527
 528         err = -ENOMEM;
 529         root = get_root_inode(sb, d.rootmode);
 530         if (!root)
 531                 goto err;
 532
 533         root_dentry = d_alloc_root(root);
 534         if (!root_dentry) {
 535                 iput(root);
 536                 goto err;
 537         }
 538
 539         init_req = fuse_request_alloc();
 540         if (!init_req)
 541                 goto err_put_root;
 542
 543         err = kobject_set_name(&fc->kobj, "%llu", conn_id());
 544         if (err)
 545                 goto err_free_req;
 546
 547         err = kobject_add(&fc->kobj);
 548         if (err)
 549                 goto err_free_req;
 550
 551         sb->s_root = root_dentry;
 552         fc->connected = 1;
 553         kobject_get(&fc->kobj);
 554         file->private_data = fc;
 555         /*
 556          * atomic_dec_and_test() in fput() provides the necessary
 557          * memory barrier for file->private_data to be visible on all
 558          * CPUs after this
 559          */
 560         fput(file);
 561
 562         fuse_send_init(fc, init_req);
 563
 564         return 0;
 565
 566  err_free_req:
 567         fuse_request_free(init_req);
 568  err_put_root:
 569         dput(root_dentry);
 570  err:
 571         fput(file);
 572         kobject_put(&fc->kobj);
 573         return err;
 574 }
 575
 576 static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
 577                                        int flags, const char *dev_name,
 578                                        void *raw_data)
 579 {
 580         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
 581 }
 582
 583 static struct file_system_type fuse_fs_type = {
 584         .owner          = THIS_MODULE,
 585         .name           = "fuse",
 586         .get_sb         = fuse_get_sb,
 587         .kill_sb        = kill_anon_super,
 588 };
 589
 590 static ssize_t fuse_conn_waiting_show(struct fuse_conn *fc, char *page)
 591 {
 592         return sprintf(page, "%i\n", atomic_read(&fc->num_waiting));
 593 }
 594
 595 static ssize_t fuse_conn_abort_store(struct fuse_conn *fc, const char *page,
 596                                      size_t count)
 597 {
 598         fuse_abort_conn(fc);
 599         return count;
 600 }
 601
 602 static struct fuse_conn_attr fuse_conn_waiting =
 603         __ATTR(waiting, 0400, fuse_conn_waiting_show, NULL);
 604 static struct fuse_conn_attr fuse_conn_abort =
 605         __ATTR(abort, 0600, NULL, fuse_conn_abort_store);
 606
 607 static struct attribute *fuse_conn_attrs[] = {
 608         &fuse_conn_waiting.attr,
 609         &fuse_conn_abort.attr,
 610         NULL,
 611 };
 612
 613 static ssize_t fuse_conn_attr_show(struct kobject *kobj,
 614                                    struct attribute *attr,
 615                                    char *page)
 616 {
 617         struct fuse_conn_attr *fca =
 618                 container_of(attr, struct fuse_conn_attr, attr);
 619
 620         if (fca->show)
 621                 return fca->show(get_fuse_conn_kobj(kobj), page);
 622         else
 623                 return -EACCES;
 624 }
 625
 626 static ssize_t fuse_conn_attr_store(struct kobject *kobj,
 627                                     struct attribute *attr,
 628                                     const char *page, size_t count)
 629 {
 630         struct fuse_conn_attr *fca =
 631                 container_of(attr, struct fuse_conn_attr, attr);
 632
 633         if (fca->store)
 634                 return fca->store(get_fuse_conn_kobj(kobj), page, count);
 635         else
 636                 return -EACCES;
 637 }
 638
 639 static struct sysfs_ops fuse_conn_sysfs_ops = {
 640         .show   = &fuse_conn_attr_show,
 641         .store  = &fuse_conn_attr_store,
 642 };
 643
 644 static struct kobj_type ktype_fuse_conn = {
 645         .release        = fuse_conn_release,
 646         .sysfs_ops      = &fuse_conn_sysfs_ops,
 647         .default_attrs  = fuse_conn_attrs,
 648 };
 649
 650 static decl_subsys(fuse, NULL, NULL);
 651 static decl_subsys(connections, &ktype_fuse_conn, NULL);
 652
 653 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
 654                                  unsigned long flags)
 655 {
 656         struct inode * inode = foo;
 657
 658         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 659             SLAB_CTOR_CONSTRUCTOR)
 660                 inode_init_once(inode);
 661 }
 662
 663 static int __init fuse_fs_init(void)
 664 {
 665         int err;
 666
 667         err = register_filesystem(&fuse_fs_type);
 668         if (err)
 669                 printk("fuse: failed to register filesystem\n");
 670         else {
 671                 fuse_inode_cachep = kmem_cache_create("fuse_inode",
 672                                                       sizeof(struct fuse_inode),
 673                                                       0, SLAB_HWCACHE_ALIGN,
 674                                                       fuse_inode_init_once, NULL);
 675                 if (!fuse_inode_cachep) {
 676                         unregister_filesystem(&fuse_fs_type);
 677                         err = -ENOMEM;
 678                 }
 679         }
 680
 681         return err;
 682 }
 683
 684 static void fuse_fs_cleanup(void)
 685 {
 686         unregister_filesystem(&fuse_fs_type);
 687         kmem_cache_destroy(fuse_inode_cachep);
 688 }
 689
 690 static int fuse_sysfs_init(void)
 691 {
 692         int err;
 693
 694         kset_set_kset_s(&fuse_subsys, fs_subsys);
 695         err = subsystem_register(&fuse_subsys);
 696         if (err)
 697                 goto out_err;
 698
 699         kset_set_kset_s(&connections_subsys, fuse_subsys);
 700         err = subsystem_register(&connections_subsys);
 701         if (err)
 702                 goto out_fuse_unregister;
 703
 704         return 0;
 705
 706  out_fuse_unregister:
 707         subsystem_unregister(&fuse_subsys);
 708  out_err:
 709         return err;
 710 }
 711
 712 static void fuse_sysfs_cleanup(void)
 713 {
 714         subsystem_unregister(&connections_subsys);
 715         subsystem_unregister(&fuse_subsys);
 716 }
 717
 718 static int __init fuse_init(void)
 719 {
 720         int res;
 721
 722         printk("fuse init (API version %i.%i)\n",
 723                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 724
 725         res = fuse_fs_init();
 726         if (res)
 727                 goto err;
 728
 729         res = fuse_dev_init();
 730         if (res)
 731                 goto err_fs_cleanup;
 732
 733         res = fuse_sysfs_init();
 734         if (res)
 735                 goto err_dev_cleanup;
 736
 737         return 0;
 738
 739  err_dev_cleanup:
 740         fuse_dev_cleanup();
 741  err_fs_cleanup:
 742         fuse_fs_cleanup();
 743  err:
 744         return res;
 745 }
 746
 747 static void __exit fuse_exit(void)
 748 {
 749         printk(KERN_DEBUG "fuse exit\n");
 750
 751         fuse_sysfs_cleanup();
 752         fuse_fs_cleanup();
 753         fuse_dev_cleanup();
 754 }
 755
 756 module_init(fuse_init);
 757 module_exit(fuse_exit);