SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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         down_write(&fc->sbput_sem);
 208         while (!list_empty(&fc->background))
 209                 fuse_release_background(fc,
 210                                         list_entry(fc->background.next,
 211                                                    struct fuse_req, bg_entry));
 212
 213         spin_lock(&fc->lock);
 214         fc->mounted = 0;
 215         fc->connected = 0;
 216         spin_unlock(&fc->lock);
 217         up_write(&fc->sbput_sem);
 218         /* Flush all readers on this fs */
 219         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 220         wake_up_all(&fc->waitq);
 221         kobject_del(&fc->kobj);
 222         kobject_put(&fc->kobj);
 223 }
 224
 225 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 226 {
 227         stbuf->f_type    = FUSE_SUPER_MAGIC;
 228         stbuf->f_bsize   = attr->bsize;
 229         stbuf->f_frsize  = attr->frsize;
 230         stbuf->f_blocks  = attr->blocks;
 231         stbuf->f_bfree   = attr->bfree;
 232         stbuf->f_bavail  = attr->bavail;
 233         stbuf->f_files   = attr->files;
 234         stbuf->f_ffree   = attr->ffree;
 235         stbuf->f_namelen = attr->namelen;
 236         /* fsid is left zero */
 237 }
 238
 239 static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
 240 {
 241         struct fuse_conn *fc = get_fuse_conn_super(sb);
 242         struct fuse_req *req;
 243         struct fuse_statfs_out outarg;
 244         int err;
 245
 246         req = fuse_get_req(fc);
 247         if (IS_ERR(req))
 248                 return PTR_ERR(req);
 249
 250         memset(&outarg, 0, sizeof(outarg));
 251         req->in.numargs = 0;
 252         req->in.h.opcode = FUSE_STATFS;
 253         req->out.numargs = 1;
 254         req->out.args[0].size =
 255                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 256         req->out.args[0].value = &outarg;
 257         request_send(fc, req);
 258         err = req->out.h.error;
 259         if (!err)
 260                 convert_fuse_statfs(buf, &outarg.st);
 261         fuse_put_request(fc, req);
 262         return err;
 263 }
 264
 265 enum {
 266         OPT_FD,
 267         OPT_ROOTMODE,
 268         OPT_USER_ID,
 269         OPT_GROUP_ID,
 270         OPT_DEFAULT_PERMISSIONS,
 271         OPT_ALLOW_OTHER,
 272         OPT_MAX_READ,
 273         OPT_ERR
 274 };
 275
 276 static match_table_t tokens = {
 277         {OPT_FD,                        "fd=%u"},
 278         {OPT_ROOTMODE,                  "rootmode=%o"},
 279         {OPT_USER_ID,                   "user_id=%u"},
 280         {OPT_GROUP_ID,                  "group_id=%u"},
 281         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 282         {OPT_ALLOW_OTHER,               "allow_other"},
 283         {OPT_MAX_READ,                  "max_read=%u"},
 284         {OPT_ERR,                       NULL}
 285 };
 286
 287 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
 288 {
 289         char *p;
 290         memset(d, 0, sizeof(struct fuse_mount_data));
 291         d->max_read = ~0;
 292
 293         while ((p = strsep(&opt, ",")) != NULL) {
 294                 int token;
 295                 int value;
 296                 substring_t args[MAX_OPT_ARGS];
 297                 if (!*p)
 298                         continue;
 299
 300                 token = match_token(p, tokens, args);
 301                 switch (token) {
 302                 case OPT_FD:
 303                         if (match_int(&args[0], &value))
 304                                 return 0;
 305                         d->fd = value;
 306                         d->fd_present = 1;
 307                         break;
 308
 309                 case OPT_ROOTMODE:
 310                         if (match_octal(&args[0], &value))
 311                                 return 0;
 312                         d->rootmode = value;
 313                         d->rootmode_present = 1;
 314                         break;
 315
 316                 case OPT_USER_ID:
 317                         if (match_int(&args[0], &value))
 318                                 return 0;
 319                         d->user_id = value;
 320                         d->user_id_present = 1;
 321                         break;
 322
 323                 case OPT_GROUP_ID:
 324                         if (match_int(&args[0], &value))
 325                                 return 0;
 326                         d->group_id = value;
 327                         d->group_id_present = 1;
 328                         break;
 329
 330                 case OPT_DEFAULT_PERMISSIONS:
 331                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 332                         break;
 333
 334                 case OPT_ALLOW_OTHER:
 335                         d->flags |= FUSE_ALLOW_OTHER;
 336                         break;
 337
 338                 case OPT_MAX_READ:
 339                         if (match_int(&args[0], &value))
 340                                 return 0;
 341                         d->max_read = value;
 342                         break;
 343
 344                 default:
 345                         return 0;
 346                 }
 347         }
 348
 349         if (!d->fd_present || !d->rootmode_present ||
 350             !d->user_id_present || !d->group_id_present)
 351                 return 0;
 352
 353         return 1;
 354 }
 355
 356 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 357 {
 358         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 359
 360         seq_printf(m, ",user_id=%u", fc->user_id);
 361         seq_printf(m, ",group_id=%u", fc->group_id);
 362         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 363                 seq_puts(m, ",default_permissions");
 364         if (fc->flags & FUSE_ALLOW_OTHER)
 365                 seq_puts(m, ",allow_other");
 366         if (fc->max_read != ~0)
 367                 seq_printf(m, ",max_read=%u", fc->max_read);
 368         return 0;
 369 }
 370
 371 static void fuse_conn_release(struct kobject *kobj)
 372 {
 373         kfree(get_fuse_conn_kobj(kobj));
 374 }
 375
 376 static struct fuse_conn *new_conn(void)
 377 {
 378         struct fuse_conn *fc;
 379
 380         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 381         if (fc) {
 382                 spin_lock_init(&fc->lock);
 383                 init_waitqueue_head(&fc->waitq);
 384                 init_waitqueue_head(&fc->blocked_waitq);
 385                 INIT_LIST_HEAD(&fc->pending);
 386                 INIT_LIST_HEAD(&fc->processing);
 387                 INIT_LIST_HEAD(&fc->io);
 388                 INIT_LIST_HEAD(&fc->background);
 389                 init_rwsem(&fc->sbput_sem);
 390                 kobj_set_kset_s(fc, connections_subsys);
 391                 kobject_init(&fc->kobj);
 392                 atomic_set(&fc->num_waiting, 0);
 393                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 394                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 395                 fc->reqctr = 0;
 396                 fc->blocked = 1;
 397         }
 398         return fc;
 399 }
 400
 401 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 402 {
 403         struct fuse_attr attr;
 404         memset(&attr, 0, sizeof(attr));
 405
 406         attr.mode = mode;
 407         attr.ino = FUSE_ROOT_ID;
 408         return fuse_iget(sb, 1, 0, &attr);
 409 }
 410
 411 static struct super_operations fuse_super_operations = {
 412         .alloc_inode    = fuse_alloc_inode,
 413         .destroy_inode  = fuse_destroy_inode,
 414         .read_inode     = fuse_read_inode,
 415         .clear_inode    = fuse_clear_inode,
 416         .put_super      = fuse_put_super,
 417         .umount_begin   = fuse_umount_begin,
 418         .statfs         = fuse_statfs,
 419         .show_options   = fuse_show_options,
 420 };
 421
 422 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 423 {
 424         struct fuse_init_out *arg = &req->misc.init_out;
 425
 426         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 427                 fc->conn_error = 1;
 428         else {
 429                 unsigned long ra_pages;
 430
 431                 if (arg->minor >= 6) {
 432                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 433                         if (arg->flags & FUSE_ASYNC_READ)
 434                                 fc->async_read = 1;
 435                 } else
 436                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 437
 438                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 439                 fc->minor = arg->minor;
 440                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 441         }
 442         fuse_put_request(fc, req);
 443         fc->blocked = 0;
 444         wake_up_all(&fc->blocked_waitq);
 445 }
 446
 447 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 448 {
 449         struct fuse_init_in *arg = &req->misc.init_in;
 450
 451         arg->major = FUSE_KERNEL_VERSION;
 452         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 453         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 454         arg->flags |= FUSE_ASYNC_READ;
 455         req->in.h.opcode = FUSE_INIT;
 456         req->in.numargs = 1;
 457         req->in.args[0].size = sizeof(*arg);
 458         req->in.args[0].value = arg;
 459         req->out.numargs = 1;
 460         /* Variable length arguement used for backward compatibility
 461            with interface version < 7.5.  Rest of init_out is zeroed
 462            by do_get_request(), so a short reply is not a problem */
 463         req->out.argvar = 1;
 464         req->out.args[0].size = sizeof(struct fuse_init_out);
 465         req->out.args[0].value = &req->misc.init_out;
 466         req->end = process_init_reply;
 467         request_send_background(fc, req);
 468 }
 469
 470 static unsigned long long conn_id(void)
 471 {
 472         /* BKL is held for ->get_sb() */
 473         static unsigned long long ctr = 1;
 474         return ctr++;
 475 }
 476
 477 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 478 {
 479         struct fuse_conn *fc;
 480         struct inode *root;
 481         struct fuse_mount_data d;
 482         struct file *file;
 483         struct dentry *root_dentry;
 484         struct fuse_req *init_req;
 485         int err;
 486
 487         if (!parse_fuse_opt((char *) data, &d))
 488                 return -EINVAL;
 489
 490         sb->s_blocksize = PAGE_CACHE_SIZE;
 491         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 492         sb->s_magic = FUSE_SUPER_MAGIC;
 493         sb->s_op = &fuse_super_operations;
 494         sb->s_maxbytes = MAX_LFS_FILESIZE;
 495
 496         file = fget(d.fd);
 497         if (!file)
 498                 return -EINVAL;
 499
 500         if (file->f_op != &fuse_dev_operations)
 501                 return -EINVAL;
 502
 503         fc = new_conn();
 504         if (!fc)
 505                 return -ENOMEM;
 506
 507         fc->flags = d.flags;
 508         fc->user_id = d.user_id;
 509         fc->group_id = d.group_id;
 510         fc->max_read = d.max_read;
 511
 512         /* Used by get_root_inode() */
 513         sb->s_fs_info = fc;
 514
 515         err = -ENOMEM;
 516         root = get_root_inode(sb, d.rootmode);
 517         if (!root)
 518                 goto err;
 519
 520         root_dentry = d_alloc_root(root);
 521         if (!root_dentry) {
 522                 iput(root);
 523                 goto err;
 524         }
 525
 526         init_req = fuse_request_alloc();
 527         if (!init_req)
 528                 goto err_put_root;
 529
 530         err = kobject_set_name(&fc->kobj, "%llu", conn_id());
 531         if (err)
 532                 goto err_free_req;
 533
 534         err = kobject_add(&fc->kobj);
 535         if (err)
 536                 goto err_free_req;
 537
 538         /* Setting file->private_data can't race with other mount()
 539            instances, since BKL is held for ->get_sb() */
 540         err = -EINVAL;
 541         if (file->private_data)
 542                 goto err_kobject_del;
 543
 544         sb->s_root = root_dentry;
 545         fc->mounted = 1;
 546         fc->connected = 1;
 547         kobject_get(&fc->kobj);
 548         file->private_data = fc;
 549         /*
 550          * atomic_dec_and_test() in fput() provides the necessary
 551          * memory barrier for file->private_data to be visible on all
 552          * CPUs after this
 553          */
 554         fput(file);
 555
 556         fuse_send_init(fc, init_req);
 557
 558         return 0;
 559
 560  err_kobject_del:
 561         kobject_del(&fc->kobj);
 562  err_free_req:
 563         fuse_request_free(init_req);
 564  err_put_root:
 565         dput(root_dentry);
 566  err:
 567         fput(file);
 568         kobject_put(&fc->kobj);
 569         return err;
 570 }
 571
 572 static int fuse_get_sb(struct file_system_type *fs_type,
 573                        int flags, const char *dev_name,
 574                        void *raw_data, struct vfsmount *mnt)
 575 {
 576         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 577 }
 578
 579 static struct file_system_type fuse_fs_type = {
 580         .owner          = THIS_MODULE,
 581         .name           = "fuse",
 582         .get_sb         = fuse_get_sb,
 583         .kill_sb        = kill_anon_super,
 584 };
 585
 586 static ssize_t fuse_conn_waiting_show(struct fuse_conn *fc, char *page)
 587 {
 588         return sprintf(page, "%i\n", atomic_read(&fc->num_waiting));
 589 }
 590
 591 static ssize_t fuse_conn_abort_store(struct fuse_conn *fc, const char *page,
 592                                      size_t count)
 593 {
 594         fuse_abort_conn(fc);
 595         return count;
 596 }
 597
 598 static struct fuse_conn_attr fuse_conn_waiting =
 599         __ATTR(waiting, 0400, fuse_conn_waiting_show, NULL);
 600 static struct fuse_conn_attr fuse_conn_abort =
 601         __ATTR(abort, 0600, NULL, fuse_conn_abort_store);
 602
 603 static struct attribute *fuse_conn_attrs[] = {
 604         &fuse_conn_waiting.attr,
 605         &fuse_conn_abort.attr,
 606         NULL,
 607 };
 608
 609 static ssize_t fuse_conn_attr_show(struct kobject *kobj,
 610                                    struct attribute *attr,
 611                                    char *page)
 612 {
 613         struct fuse_conn_attr *fca =
 614                 container_of(attr, struct fuse_conn_attr, attr);
 615
 616         if (fca->show)
 617                 return fca->show(get_fuse_conn_kobj(kobj), page);
 618         else
 619                 return -EACCES;
 620 }
 621
 622 static ssize_t fuse_conn_attr_store(struct kobject *kobj,
 623                                     struct attribute *attr,
 624                                     const char *page, size_t count)
 625 {
 626         struct fuse_conn_attr *fca =
 627                 container_of(attr, struct fuse_conn_attr, attr);
 628
 629         if (fca->store)
 630                 return fca->store(get_fuse_conn_kobj(kobj), page, count);
 631         else
 632                 return -EACCES;
 633 }
 634
 635 static struct sysfs_ops fuse_conn_sysfs_ops = {
 636         .show   = &fuse_conn_attr_show,
 637         .store  = &fuse_conn_attr_store,
 638 };
 639
 640 static struct kobj_type ktype_fuse_conn = {
 641         .release        = fuse_conn_release,
 642         .sysfs_ops      = &fuse_conn_sysfs_ops,
 643         .default_attrs  = fuse_conn_attrs,
 644 };
 645
 646 static decl_subsys(fuse, NULL, NULL);
 647 static decl_subsys(connections, &ktype_fuse_conn, NULL);
 648
 649 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
 650                                  unsigned long flags)
 651 {
 652         struct inode * inode = foo;
 653
 654         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 655             SLAB_CTOR_CONSTRUCTOR)
 656                 inode_init_once(inode);
 657 }
 658
 659 static int __init fuse_fs_init(void)
 660 {
 661         int err;
 662
 663         err = register_filesystem(&fuse_fs_type);
 664         if (err)
 665                 printk("fuse: failed to register filesystem\n");
 666         else {
 667                 fuse_inode_cachep = kmem_cache_create("fuse_inode",
 668                                                       sizeof(struct fuse_inode),
 669                                                       0, SLAB_HWCACHE_ALIGN,
 670                                                       fuse_inode_init_once, NULL);
 671                 if (!fuse_inode_cachep) {
 672                         unregister_filesystem(&fuse_fs_type);
 673                         err = -ENOMEM;
 674                 }
 675         }
 676
 677         return err;
 678 }
 679
 680 static void fuse_fs_cleanup(void)
 681 {
 682         unregister_filesystem(&fuse_fs_type);
 683         kmem_cache_destroy(fuse_inode_cachep);
 684 }
 685
 686 static int fuse_sysfs_init(void)
 687 {
 688         int err;
 689
 690         kset_set_kset_s(&fuse_subsys, fs_subsys);
 691         err = subsystem_register(&fuse_subsys);
 692         if (err)
 693                 goto out_err;
 694
 695         kset_set_kset_s(&connections_subsys, fuse_subsys);
 696         err = subsystem_register(&connections_subsys);
 697         if (err)
 698                 goto out_fuse_unregister;
 699
 700         return 0;
 701
 702  out_fuse_unregister:
 703         subsystem_unregister(&fuse_subsys);
 704  out_err:
 705         return err;
 706 }
 707
 708 static void fuse_sysfs_cleanup(void)
 709 {
 710         subsystem_unregister(&connections_subsys);
 711         subsystem_unregister(&fuse_subsys);
 712 }
 713
 714 static int __init fuse_init(void)
 715 {
 716         int res;
 717
 718         printk("fuse init (API version %i.%i)\n",
 719                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 720
 721         res = fuse_fs_init();
 722         if (res)
 723                 goto err;
 724
 725         res = fuse_dev_init();
 726         if (res)
 727                 goto err_fs_cleanup;
 728
 729         res = fuse_sysfs_init();
 730         if (res)
 731                 goto err_dev_cleanup;
 732
 733         return 0;
 734
 735  err_dev_cleanup:
 736         fuse_dev_cleanup();
 737  err_fs_cleanup:
 738         fuse_fs_cleanup();
 739  err:
 740         return res;
 741 }
 742
 743 static void __exit fuse_exit(void)
 744 {
 745         printk(KERN_DEBUG "fuse exit\n");
 746
 747         fuse_sysfs_cleanup();
 748         fuse_fs_cleanup();
 749         fuse_dev_cleanup();
 750 }
 751
 752 module_init(fuse_init);
 753 module_exit(fuse_exit);