fs/fuse/inode.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2005  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 spinlock_t fuse_lock;
  26 static kmem_cache_t *fuse_inode_cachep;
  27 static struct subsystem connections_subsys;
  28
  29 struct fuse_conn_attr {
  30         struct attribute attr;
  31         ssize_t (*show)(struct fuse_conn *, char *);
  32         ssize_t (*store)(struct fuse_conn *, const char *, size_t);
  33 };
  34
  35 #define FUSE_SUPER_MAGIC 0x65735546
  36
  37 struct fuse_mount_data {
  38         int fd;
  39         unsigned rootmode;
  40         unsigned user_id;
  41         unsigned group_id;
  42         unsigned fd_present : 1;
  43         unsigned rootmode_present : 1;
  44         unsigned user_id_present : 1;
  45         unsigned group_id_present : 1;
  46         unsigned flags;
  47         unsigned max_read;
  48 };
  49
  50 static struct inode *fuse_alloc_inode(struct super_block *sb)
  51 {
  52         struct inode *inode;
  53         struct fuse_inode *fi;
  54
  55         inode = kmem_cache_alloc(fuse_inode_cachep, SLAB_KERNEL);
  56         if (!inode)
  57                 return NULL;
  58
  59         fi = get_fuse_inode(inode);
  60         fi->i_time = jiffies - 1;
  61         fi->nodeid = 0;
  62         fi->nlookup = 0;
  63         fi->forget_req = fuse_request_alloc();
  64         if (!fi->forget_req) {
  65                 kmem_cache_free(fuse_inode_cachep, inode);
  66                 return NULL;
  67         }
  68
  69         return inode;
  70 }
  71
  72 static void fuse_destroy_inode(struct inode *inode)
  73 {
  74         struct fuse_inode *fi = get_fuse_inode(inode);
  75         if (fi->forget_req)
  76                 fuse_request_free(fi->forget_req);
  77         kmem_cache_free(fuse_inode_cachep, inode);
  78 }
  79
  80 static void fuse_read_inode(struct inode *inode)
  81 {
  82         /* No op */
  83 }
  84
  85 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
  86                       unsigned long nodeid, u64 nlookup)
  87 {
  88         struct fuse_forget_in *inarg = &req->misc.forget_in;
  89         inarg->nlookup = nlookup;
  90         req->in.h.opcode = FUSE_FORGET;
  91         req->in.h.nodeid = nodeid;
  92         req->in.numargs = 1;
  93         req->in.args[0].size = sizeof(struct fuse_forget_in);
  94         req->in.args[0].value = inarg;
  95         request_send_noreply(fc, req);
  96 }
  97
  98 static void fuse_clear_inode(struct inode *inode)
  99 {
 100         if (inode->i_sb->s_flags & MS_ACTIVE) {
 101                 struct fuse_conn *fc = get_fuse_conn(inode);
 102                 struct fuse_inode *fi = get_fuse_inode(inode);
 103                 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
 104                 fi->forget_req = NULL;
 105         }
 106 }
 107
 108 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
 109 {
 110         if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
 111                 invalidate_inode_pages(inode->i_mapping);
 112
 113         inode->i_ino     = attr->ino;
 114         inode->i_mode    = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
 115         inode->i_nlink   = attr->nlink;
 116         inode->i_uid     = attr->uid;
 117         inode->i_gid     = attr->gid;
 118         i_size_write(inode, attr->size);
 119         inode->i_blksize = PAGE_CACHE_SIZE;
 120         inode->i_blocks  = attr->blocks;
 121         inode->i_atime.tv_sec   = attr->atime;
 122         inode->i_atime.tv_nsec  = attr->atimensec;
 123         inode->i_mtime.tv_sec   = attr->mtime;
 124         inode->i_mtime.tv_nsec  = attr->mtimensec;
 125         inode->i_ctime.tv_sec   = attr->ctime;
 126         inode->i_ctime.tv_nsec  = attr->ctimensec;
 127 }
 128
 129 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 130 {
 131         inode->i_mode = attr->mode & S_IFMT;
 132         i_size_write(inode, attr->size);
 133         if (S_ISREG(inode->i_mode)) {
 134                 fuse_init_common(inode);
 135                 fuse_init_file_inode(inode);
 136         } else if (S_ISDIR(inode->i_mode))
 137                 fuse_init_dir(inode);
 138         else if (S_ISLNK(inode->i_mode))
 139                 fuse_init_symlink(inode);
 140         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 141                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 142                 fuse_init_common(inode);
 143                 init_special_inode(inode, inode->i_mode,
 144                                    new_decode_dev(attr->rdev));
 145         } else
 146                 BUG();
 147 }
 148
 149 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 150 {
 151         unsigned long nodeid = *(unsigned long *) _nodeidp;
 152         if (get_node_id(inode) == nodeid)
 153                 return 1;
 154         else
 155                 return 0;
 156 }
 157
 158 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 159 {
 160         unsigned long nodeid = *(unsigned long *) _nodeidp;
 161         get_fuse_inode(inode)->nodeid = nodeid;
 162         return 0;
 163 }
 164
 165 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 166                         int generation, struct fuse_attr *attr)
 167 {
 168         struct inode *inode;
 169         struct fuse_inode *fi;
 170         struct fuse_conn *fc = get_fuse_conn_super(sb);
 171         int retried = 0;
 172
 173  retry:
 174         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 175         if (!inode)
 176                 return NULL;
 177
 178         if ((inode->i_state & I_NEW)) {
 179                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
 180                 inode->i_generation = generation;
 181                 inode->i_data.backing_dev_info = &fc->bdi;
 182                 fuse_init_inode(inode, attr);
 183                 unlock_new_inode(inode);
 184         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 185                 BUG_ON(retried);
 186                 /* Inode has changed type, any I/O on the old should fail */
 187                 make_bad_inode(inode);
 188                 iput(inode);
 189                 retried = 1;
 190                 goto retry;
 191         }
 192
 193         fi = get_fuse_inode(inode);
 194         fi->nlookup ++;
 195         fuse_change_attributes(inode, attr);
 196         return inode;
 197 }
 198
 199 static void fuse_umount_begin(struct super_block *sb)
 200 {
 201         fuse_abort_conn(get_fuse_conn_super(sb));
 202 }
 203
 204 static void fuse_put_super(struct super_block *sb)
 205 {
 206         struct fuse_conn *fc = get_fuse_conn_super(sb);
 207
 208         down_write(&fc->sbput_sem);
 209         while (!list_empty(&fc->background))
 210                 fuse_release_background(list_entry(fc->background.next,
 211                                                    struct fuse_req, bg_entry));
 212
 213         spin_lock(&fuse_lock);
 214         fc->mounted = 0;
 215         fc->connected = 0;
 216         spin_unlock(&fuse_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_request(fc);
 247         if (!req)
 248                 return -EINTR;
 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         struct fuse_conn *fc = get_fuse_conn_kobj(kobj);
 374
 375         while (!list_empty(&fc->unused_list)) {
 376                 struct fuse_req *req;
 377                 req = list_entry(fc->unused_list.next, struct fuse_req, list);
 378                 list_del(&req->list);
 379                 fuse_request_free(req);
 380         }
 381         kfree(fc);
 382 }
 383
 384 static struct fuse_conn *new_conn(void)
 385 {
 386         struct fuse_conn *fc;
 387
 388         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 389         if (fc) {
 390                 int i;
 391                 init_waitqueue_head(&fc->waitq);
 392                 INIT_LIST_HEAD(&fc->pending);
 393                 INIT_LIST_HEAD(&fc->processing);
 394                 INIT_LIST_HEAD(&fc->io);
 395                 INIT_LIST_HEAD(&fc->unused_list);
 396                 INIT_LIST_HEAD(&fc->background);
 397                 sema_init(&fc->outstanding_sem, 1); /* One for INIT */
 398                 init_rwsem(&fc->sbput_sem);
 399                 kobj_set_kset_s(fc, connections_subsys);
 400                 kobject_init(&fc->kobj);
 401                 atomic_set(&fc->num_waiting, 0);
 402                 for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
 403                         struct fuse_req *req = fuse_request_alloc();
 404                         if (!req) {
 405                                 kobject_put(&fc->kobj);
 406                                 return NULL;
 407                         }
 408                         list_add(&req->list, &fc->unused_list);
 409                 }
 410                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 411                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 412                 fc->reqctr = 0;
 413         }
 414         return fc;
 415 }
 416
 417 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 418 {
 419         struct fuse_attr attr;
 420         memset(&attr, 0, sizeof(attr));
 421
 422         attr.mode = mode;
 423         attr.ino = FUSE_ROOT_ID;
 424         return fuse_iget(sb, 1, 0, &attr);
 425 }
 426
 427 static struct super_operations fuse_super_operations = {
 428         .alloc_inode    = fuse_alloc_inode,
 429         .destroy_inode  = fuse_destroy_inode,
 430         .read_inode     = fuse_read_inode,
 431         .clear_inode    = fuse_clear_inode,
 432         .put_super      = fuse_put_super,
 433         .umount_begin   = fuse_umount_begin,
 434         .statfs         = fuse_statfs,
 435         .show_options   = fuse_show_options,
 436 };
 437
 438 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 439 {
 440         int i;
 441         struct fuse_init_out *arg = &req->misc.init_out;
 442
 443         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 444                 fc->conn_error = 1;
 445         else {
 446                 unsigned long ra_pages;
 447
 448                 if (arg->minor >= 6) {
 449                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 450                         if (arg->flags & FUSE_ASYNC_READ)
 451                                 fc->async_read = 1;
 452                 } else
 453                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 454
 455                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 456                 fc->minor = arg->minor;
 457                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 458         }
 459
 460         /* After INIT reply is received other requests can go
 461            out.  So do (FUSE_MAX_OUTSTANDING - 1) number of
 462            up()s on outstanding_sem.  The last up() is done in
 463            fuse_putback_request() */
 464         for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
 465                 up(&fc->outstanding_sem);
 466
 467         fuse_put_request(fc, req);
 468 }
 469
 470 static void fuse_send_init(struct fuse_conn *fc)
 471 {
 472         /* This is called from fuse_read_super() so there's guaranteed
 473            to be exactly one request available */
 474         struct fuse_req *req = fuse_get_request(fc);
 475         struct fuse_init_in *arg = &req->misc.init_in;
 476
 477         arg->major = FUSE_KERNEL_VERSION;
 478         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 479         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 480         arg->flags |= FUSE_ASYNC_READ;
 481         req->in.h.opcode = FUSE_INIT;
 482         req->in.numargs = 1;
 483         req->in.args[0].size = sizeof(*arg);
 484         req->in.args[0].value = arg;
 485         req->out.numargs = 1;
 486         /* Variable length arguement used for backward compatibility
 487            with interface version < 7.5.  Rest of init_out is zeroed
 488            by do_get_request(), so a short reply is not a problem */
 489         req->out.argvar = 1;
 490         req->out.args[0].size = sizeof(struct fuse_init_out);
 491         req->out.args[0].value = &req->misc.init_out;
 492         req->end = process_init_reply;
 493         request_send_background(fc, req);
 494 }
 495
 496 static unsigned long long conn_id(void)
 497 {
 498         /* BKL is held for ->get_sb() */
 499         static unsigned long long ctr = 1;
 500         return ctr++;
 501 }
 502
 503 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 504 {
 505         struct fuse_conn *fc;
 506         struct inode *root;
 507         struct fuse_mount_data d;
 508         struct file *file;
 509         struct dentry *root_dentry;
 510         int err;
 511
 512         if (!parse_fuse_opt((char *) data, &d))
 513                 return -EINVAL;
 514
 515         sb->s_blocksize = PAGE_CACHE_SIZE;
 516         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 517         sb->s_magic = FUSE_SUPER_MAGIC;
 518         sb->s_op = &fuse_super_operations;
 519         sb->s_maxbytes = MAX_LFS_FILESIZE;
 520
 521         file = fget(d.fd);
 522         if (!file)
 523                 return -EINVAL;
 524
 525         if (file->f_op != &fuse_dev_operations)
 526                 return -EINVAL;
 527
 528         /* Setting file->private_data can't race with other mount()
 529            instances, since BKL is held for ->get_sb() */
 530         if (file->private_data)
 531                 return -EINVAL;
 532
 533         fc = new_conn();
 534         if (!fc)
 535                 return -ENOMEM;
 536
 537         fc->flags = d.flags;
 538         fc->user_id = d.user_id;
 539         fc->group_id = d.group_id;
 540         fc->max_read = d.max_read;
 541
 542         /* Used by get_root_inode() */
 543         sb->s_fs_info = fc;
 544
 545         err = -ENOMEM;
 546         root = get_root_inode(sb, d.rootmode);
 547         if (!root)
 548                 goto err;
 549
 550         root_dentry = d_alloc_root(root);
 551         if (!root_dentry) {
 552                 iput(root);
 553                 goto err;
 554         }
 555
 556         err = kobject_set_name(&fc->kobj, "%llu", conn_id());
 557         if (err)
 558                 goto err_put_root;
 559
 560         err = kobject_add(&fc->kobj);
 561         if (err)
 562                 goto err_put_root;
 563
 564         sb->s_root = root_dentry;
 565         fc->mounted = 1;
 566         fc->connected = 1;
 567         kobject_get(&fc->kobj);
 568         file->private_data = fc;
 569         /*
 570          * atomic_dec_and_test() in fput() provides the necessary
 571          * memory barrier for file->private_data to be visible on all
 572          * CPUs after this
 573          */
 574         fput(file);
 575
 576         fuse_send_init(fc);
 577
 578         return 0;
 579
 580  err_put_root:
 581         dput(root_dentry);
 582  err:
 583         fput(file);
 584         kobject_put(&fc->kobj);
 585         return err;
 586 }
 587
 588 static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
 589                                        int flags, const char *dev_name,
 590                                        void *raw_data)
 591 {
 592         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
 593 }
 594
 595 static struct file_system_type fuse_fs_type = {
 596         .owner          = THIS_MODULE,
 597         .name           = "fuse",
 598         .get_sb         = fuse_get_sb,
 599         .kill_sb        = kill_anon_super,
 600 };
 601
 602 static ssize_t fuse_conn_waiting_show(struct fuse_conn *fc, char *page)
 603 {
 604         return sprintf(page, "%i\n", atomic_read(&fc->num_waiting));
 605 }
 606
 607 static ssize_t fuse_conn_abort_store(struct fuse_conn *fc, const char *page,
 608                                      size_t count)
 609 {
 610         fuse_abort_conn(fc);
 611         return count;
 612 }
 613
 614 static struct fuse_conn_attr fuse_conn_waiting =
 615         __ATTR(waiting, 0400, fuse_conn_waiting_show, NULL);
 616 static struct fuse_conn_attr fuse_conn_abort =
 617         __ATTR(abort, 0600, NULL, fuse_conn_abort_store);
 618
 619 static struct attribute *fuse_conn_attrs[] = {
 620         &fuse_conn_waiting.attr,
 621         &fuse_conn_abort.attr,
 622         NULL,
 623 };
 624
 625 static ssize_t fuse_conn_attr_show(struct kobject *kobj,
 626                                    struct attribute *attr,
 627                                    char *page)
 628 {
 629         struct fuse_conn_attr *fca =
 630                 container_of(attr, struct fuse_conn_attr, attr);
 631
 632         if (fca->show)
 633                 return fca->show(get_fuse_conn_kobj(kobj), page);
 634         else
 635                 return -EACCES;
 636 }
 637
 638 static ssize_t fuse_conn_attr_store(struct kobject *kobj,
 639                                     struct attribute *attr,
 640                                     const char *page, size_t count)
 641 {
 642         struct fuse_conn_attr *fca =
 643                 container_of(attr, struct fuse_conn_attr, attr);
 644
 645         if (fca->store)
 646                 return fca->store(get_fuse_conn_kobj(kobj), page, count);
 647         else
 648                 return -EACCES;
 649 }
 650
 651 static struct sysfs_ops fuse_conn_sysfs_ops = {
 652         .show   = &fuse_conn_attr_show,
 653         .store  = &fuse_conn_attr_store,
 654 };
 655
 656 static struct kobj_type ktype_fuse_conn = {
 657         .release        = fuse_conn_release,
 658         .sysfs_ops      = &fuse_conn_sysfs_ops,
 659         .default_attrs  = fuse_conn_attrs,
 660 };
 661
 662 static decl_subsys(fuse, NULL, NULL);
 663 static decl_subsys(connections, &ktype_fuse_conn, NULL);
 664
 665 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
 666                                  unsigned long flags)
 667 {
 668         struct inode * inode = foo;
 669
 670         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 671             SLAB_CTOR_CONSTRUCTOR)
 672                 inode_init_once(inode);
 673 }
 674
 675 static int __init fuse_fs_init(void)
 676 {
 677         int err;
 678
 679         err = register_filesystem(&fuse_fs_type);
 680         if (err)
 681                 printk("fuse: failed to register filesystem\n");
 682         else {
 683                 fuse_inode_cachep = kmem_cache_create("fuse_inode",
 684                                                       sizeof(struct fuse_inode),
 685                                                       0, SLAB_HWCACHE_ALIGN,
 686                                                       fuse_inode_init_once, NULL);
 687                 if (!fuse_inode_cachep) {
 688                         unregister_filesystem(&fuse_fs_type);
 689                         err = -ENOMEM;
 690                 }
 691         }
 692
 693         return err;
 694 }
 695
 696 static void fuse_fs_cleanup(void)
 697 {
 698         unregister_filesystem(&fuse_fs_type);
 699         kmem_cache_destroy(fuse_inode_cachep);
 700 }
 701
 702 static int fuse_sysfs_init(void)
 703 {
 704         int err;
 705
 706         kset_set_kset_s(&fuse_subsys, fs_subsys);
 707         err = subsystem_register(&fuse_subsys);
 708         if (err)
 709                 goto out_err;
 710
 711         kset_set_kset_s(&connections_subsys, fuse_subsys);
 712         err = subsystem_register(&connections_subsys);
 713         if (err)
 714                 goto out_fuse_unregister;
 715
 716         return 0;
 717
 718  out_fuse_unregister:
 719         subsystem_unregister(&fuse_subsys);
 720  out_err:
 721         return err;
 722 }
 723
 724 static void fuse_sysfs_cleanup(void)
 725 {
 726         subsystem_unregister(&connections_subsys);
 727         subsystem_unregister(&fuse_subsys);
 728 }
 729
 730 static int __init fuse_init(void)
 731 {
 732         int res;
 733
 734         printk("fuse init (API version %i.%i)\n",
 735                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 736
 737         spin_lock_init(&fuse_lock);
 738         res = fuse_fs_init();
 739         if (res)
 740                 goto err;
 741
 742         res = fuse_dev_init();
 743         if (res)
 744                 goto err_fs_cleanup;
 745
 746         res = fuse_sysfs_init();
 747         if (res)
 748                 goto err_dev_cleanup;
 749
 750         return 0;
 751
 752  err_dev_cleanup:
 753         fuse_dev_cleanup();
 754  err_fs_cleanup:
 755         fuse_fs_cleanup();
 756  err:
 757         return res;
 758 }
 759
 760 static void __exit fuse_exit(void)
 761 {
 762         printk(KERN_DEBUG "fuse exit\n");
 763
 764         fuse_sysfs_cleanup();
 765         fuse_fs_cleanup();
 766         fuse_dev_cleanup();
 767 }
 768
 769 module_init(fuse_init);
 770 module_exit(fuse_exit);