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         spin_lock(&fuse_lock);
 119         i_size_write(inode, attr->size);
 120         spin_unlock(&fuse_lock);
 121         inode->i_blksize = PAGE_CACHE_SIZE;
 122         inode->i_blocks  = attr->blocks;
 123         inode->i_atime.tv_sec   = attr->atime;
 124         inode->i_atime.tv_nsec  = attr->atimensec;
 125         inode->i_mtime.tv_sec   = attr->mtime;
 126         inode->i_mtime.tv_nsec  = attr->mtimensec;
 127         inode->i_ctime.tv_sec   = attr->ctime;
 128         inode->i_ctime.tv_nsec  = attr->ctimensec;
 129 }
 130
 131 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 132 {
 133         inode->i_mode = attr->mode & S_IFMT;
 134         inode->i_size = attr->size;
 135         if (S_ISREG(inode->i_mode)) {
 136                 fuse_init_common(inode);
 137                 fuse_init_file_inode(inode);
 138         } else if (S_ISDIR(inode->i_mode))
 139                 fuse_init_dir(inode);
 140         else if (S_ISLNK(inode->i_mode))
 141                 fuse_init_symlink(inode);
 142         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 143                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 144                 fuse_init_common(inode);
 145                 init_special_inode(inode, inode->i_mode,
 146                                    new_decode_dev(attr->rdev));
 147         } else
 148                 BUG();
 149 }
 150
 151 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 152 {
 153         unsigned long nodeid = *(unsigned long *) _nodeidp;
 154         if (get_node_id(inode) == nodeid)
 155                 return 1;
 156         else
 157                 return 0;
 158 }
 159
 160 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 161 {
 162         unsigned long nodeid = *(unsigned long *) _nodeidp;
 163         get_fuse_inode(inode)->nodeid = nodeid;
 164         return 0;
 165 }
 166
 167 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 168                         int generation, struct fuse_attr *attr)
 169 {
 170         struct inode *inode;
 171         struct fuse_inode *fi;
 172         struct fuse_conn *fc = get_fuse_conn_super(sb);
 173         int retried = 0;
 174
 175  retry:
 176         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 177         if (!inode)
 178                 return NULL;
 179
 180         if ((inode->i_state & I_NEW)) {
 181                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
 182                 inode->i_generation = generation;
 183                 inode->i_data.backing_dev_info = &fc->bdi;
 184                 fuse_init_inode(inode, attr);
 185                 unlock_new_inode(inode);
 186         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 187                 BUG_ON(retried);
 188                 /* Inode has changed type, any I/O on the old should fail */
 189                 make_bad_inode(inode);
 190                 iput(inode);
 191                 retried = 1;
 192                 goto retry;
 193         }
 194
 195         fi = get_fuse_inode(inode);
 196         fi->nlookup ++;
 197         fuse_change_attributes(inode, attr);
 198         return inode;
 199 }
 200
 201 static void fuse_umount_begin(struct super_block *sb)
 202 {
 203         fuse_abort_conn(get_fuse_conn_super(sb));
 204 }
 205
 206 static void fuse_put_super(struct super_block *sb)
 207 {
 208         struct fuse_conn *fc = get_fuse_conn_super(sb);
 209
 210         down_write(&fc->sbput_sem);
 211         while (!list_empty(&fc->background))
 212                 fuse_release_background(list_entry(fc->background.next,
 213                                                    struct fuse_req, bg_entry));
 214
 215         spin_lock(&fuse_lock);
 216         fc->mounted = 0;
 217         fc->connected = 0;
 218         spin_unlock(&fuse_lock);
 219         up_write(&fc->sbput_sem);
 220         /* Flush all readers on this fs */
 221         wake_up_all(&fc->waitq);
 222         kobject_del(&fc->kobj);
 223         kobject_put(&fc->kobj);
 224 }
 225
 226 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 227 {
 228         stbuf->f_type    = FUSE_SUPER_MAGIC;
 229         stbuf->f_bsize   = attr->bsize;
 230         stbuf->f_frsize  = attr->frsize;
 231         stbuf->f_blocks  = attr->blocks;
 232         stbuf->f_bfree   = attr->bfree;
 233         stbuf->f_bavail  = attr->bavail;
 234         stbuf->f_files   = attr->files;
 235         stbuf->f_ffree   = attr->ffree;
 236         stbuf->f_namelen = attr->namelen;
 237         /* fsid is left zero */
 238 }
 239
 240 static int fuse_statfs(struct super_block *sb, struct kstatfs *buf)
 241 {
 242         struct fuse_conn *fc = get_fuse_conn_super(sb);
 243         struct fuse_req *req;
 244         struct fuse_statfs_out outarg;
 245         int err;
 246
 247         req = fuse_get_request(fc);
 248         if (!req)
 249                 return -EINTR;
 250
 251         memset(&outarg, 0, sizeof(outarg));
 252         req->in.numargs = 0;
 253         req->in.h.opcode = FUSE_STATFS;
 254         req->out.numargs = 1;
 255         req->out.args[0].size =
 256                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 257         req->out.args[0].value = &outarg;
 258         request_send(fc, req);
 259         err = req->out.h.error;
 260         if (!err)
 261                 convert_fuse_statfs(buf, &outarg.st);
 262         fuse_put_request(fc, req);
 263         return err;
 264 }
 265
 266 enum {
 267         OPT_FD,
 268         OPT_ROOTMODE,
 269         OPT_USER_ID,
 270         OPT_GROUP_ID,
 271         OPT_DEFAULT_PERMISSIONS,
 272         OPT_ALLOW_OTHER,
 273         OPT_MAX_READ,
 274         OPT_ERR
 275 };
 276
 277 static match_table_t tokens = {
 278         {OPT_FD,                        "fd=%u"},
 279         {OPT_ROOTMODE,                  "rootmode=%o"},
 280         {OPT_USER_ID,                   "user_id=%u"},
 281         {OPT_GROUP_ID,                  "group_id=%u"},
 282         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 283         {OPT_ALLOW_OTHER,               "allow_other"},
 284         {OPT_MAX_READ,                  "max_read=%u"},
 285         {OPT_ERR,                       NULL}
 286 };
 287
 288 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d)
 289 {
 290         char *p;
 291         memset(d, 0, sizeof(struct fuse_mount_data));
 292         d->max_read = ~0;
 293
 294         while ((p = strsep(&opt, ",")) != NULL) {
 295                 int token;
 296                 int value;
 297                 substring_t args[MAX_OPT_ARGS];
 298                 if (!*p)
 299                         continue;
 300
 301                 token = match_token(p, tokens, args);
 302                 switch (token) {
 303                 case OPT_FD:
 304                         if (match_int(&args[0], &value))
 305                                 return 0;
 306                         d->fd = value;
 307                         d->fd_present = 1;
 308                         break;
 309
 310                 case OPT_ROOTMODE:
 311                         if (match_octal(&args[0], &value))
 312                                 return 0;
 313                         d->rootmode = value;
 314                         d->rootmode_present = 1;
 315                         break;
 316
 317                 case OPT_USER_ID:
 318                         if (match_int(&args[0], &value))
 319                                 return 0;
 320                         d->user_id = value;
 321                         d->user_id_present = 1;
 322                         break;
 323
 324                 case OPT_GROUP_ID:
 325                         if (match_int(&args[0], &value))
 326                                 return 0;
 327                         d->group_id = value;
 328                         d->group_id_present = 1;
 329                         break;
 330
 331                 case OPT_DEFAULT_PERMISSIONS:
 332                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 333                         break;
 334
 335                 case OPT_ALLOW_OTHER:
 336                         d->flags |= FUSE_ALLOW_OTHER;
 337                         break;
 338
 339                 case OPT_MAX_READ:
 340                         if (match_int(&args[0], &value))
 341                                 return 0;
 342                         d->max_read = value;
 343                         break;
 344
 345                 default:
 346                         return 0;
 347                 }
 348         }
 349
 350         if (!d->fd_present || !d->rootmode_present ||
 351             !d->user_id_present || !d->group_id_present)
 352                 return 0;
 353
 354         return 1;
 355 }
 356
 357 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 358 {
 359         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 360
 361         seq_printf(m, ",user_id=%u", fc->user_id);
 362         seq_printf(m, ",group_id=%u", fc->group_id);
 363         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 364                 seq_puts(m, ",default_permissions");
 365         if (fc->flags & FUSE_ALLOW_OTHER)
 366                 seq_puts(m, ",allow_other");
 367         if (fc->max_read != ~0)
 368                 seq_printf(m, ",max_read=%u", fc->max_read);
 369         return 0;
 370 }
 371
 372 static void fuse_conn_release(struct kobject *kobj)
 373 {
 374         struct fuse_conn *fc = get_fuse_conn_kobj(kobj);
 375
 376         while (!list_empty(&fc->unused_list)) {
 377                 struct fuse_req *req;
 378                 req = list_entry(fc->unused_list.next, struct fuse_req, list);
 379                 list_del(&req->list);
 380                 fuse_request_free(req);
 381         }
 382         kfree(fc);
 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                 int i;
 392                 init_waitqueue_head(&fc->waitq);
 393                 INIT_LIST_HEAD(&fc->pending);
 394                 INIT_LIST_HEAD(&fc->processing);
 395                 INIT_LIST_HEAD(&fc->io);
 396                 INIT_LIST_HEAD(&fc->unused_list);
 397                 INIT_LIST_HEAD(&fc->background);
 398                 sema_init(&fc->outstanding_sem, 1); /* One for INIT */
 399                 init_rwsem(&fc->sbput_sem);
 400                 kobj_set_kset_s(fc, connections_subsys);
 401                 kobject_init(&fc->kobj);
 402                 atomic_set(&fc->num_waiting, 0);
 403                 for (i = 0; i < FUSE_MAX_OUTSTANDING; i++) {
 404                         struct fuse_req *req = fuse_request_alloc();
 405                         if (!req) {
 406                                 kobject_put(&fc->kobj);
 407                                 return NULL;
 408                         }
 409                         list_add(&req->list, &fc->unused_list);
 410                 }
 411                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 412                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 413                 fc->reqctr = 0;
 414         }
 415         return fc;
 416 }
 417
 418 static struct fuse_conn *get_conn(struct file *file, struct super_block *sb)
 419 {
 420         struct fuse_conn *fc;
 421         int err;
 422
 423         err = -EINVAL;
 424         if (file->f_op != &fuse_dev_operations)
 425                 goto out_err;
 426
 427         err = -ENOMEM;
 428         fc = new_conn();
 429         if (!fc)
 430                 goto out_err;
 431
 432         spin_lock(&fuse_lock);
 433         err = -EINVAL;
 434         if (file->private_data)
 435                 goto out_unlock;
 436
 437         kobject_get(&fc->kobj);
 438         file->private_data = fc;
 439         spin_unlock(&fuse_lock);
 440         return fc;
 441
 442  out_unlock:
 443         spin_unlock(&fuse_lock);
 444         kobject_put(&fc->kobj);
 445  out_err:
 446         return ERR_PTR(err);
 447 }
 448
 449 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 450 {
 451         struct fuse_attr attr;
 452         memset(&attr, 0, sizeof(attr));
 453
 454         attr.mode = mode;
 455         attr.ino = FUSE_ROOT_ID;
 456         return fuse_iget(sb, 1, 0, &attr);
 457 }
 458
 459 static struct super_operations fuse_super_operations = {
 460         .alloc_inode    = fuse_alloc_inode,
 461         .destroy_inode  = fuse_destroy_inode,
 462         .read_inode     = fuse_read_inode,
 463         .clear_inode    = fuse_clear_inode,
 464         .put_super      = fuse_put_super,
 465         .umount_begin   = fuse_umount_begin,
 466         .statfs         = fuse_statfs,
 467         .show_options   = fuse_show_options,
 468 };
 469
 470 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 471 {
 472         int i;
 473         struct fuse_init_out *arg = &req->misc.init_out;
 474
 475         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 476                 fc->conn_error = 1;
 477         else {
 478                 unsigned long ra_pages;
 479
 480                 if (arg->minor >= 6) {
 481                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 482                         if (arg->flags & FUSE_ASYNC_READ)
 483                                 fc->async_read = 1;
 484                 } else
 485                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 486
 487                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 488                 fc->minor = arg->minor;
 489                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 490         }
 491
 492         /* After INIT reply is received other requests can go
 493            out.  So do (FUSE_MAX_OUTSTANDING - 1) number of
 494            up()s on outstanding_sem.  The last up() is done in
 495            fuse_putback_request() */
 496         for (i = 1; i < FUSE_MAX_OUTSTANDING; i++)
 497                 up(&fc->outstanding_sem);
 498
 499         fuse_put_request(fc, req);
 500 }
 501
 502 static void fuse_send_init(struct fuse_conn *fc)
 503 {
 504         /* This is called from fuse_read_super() so there's guaranteed
 505            to be exactly one request available */
 506         struct fuse_req *req = fuse_get_request(fc);
 507         struct fuse_init_in *arg = &req->misc.init_in;
 508
 509         arg->major = FUSE_KERNEL_VERSION;
 510         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 511         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 512         arg->flags |= FUSE_ASYNC_READ;
 513         req->in.h.opcode = FUSE_INIT;
 514         req->in.numargs = 1;
 515         req->in.args[0].size = sizeof(*arg);
 516         req->in.args[0].value = arg;
 517         req->out.numargs = 1;
 518         /* Variable length arguement used for backward compatibility
 519            with interface version < 7.5.  Rest of init_out is zeroed
 520            by do_get_request(), so a short reply is not a problem */
 521         req->out.argvar = 1;
 522         req->out.args[0].size = sizeof(struct fuse_init_out);
 523         req->out.args[0].value = &req->misc.init_out;
 524         req->end = process_init_reply;
 525         request_send_background(fc, req);
 526 }
 527
 528 static unsigned long long conn_id(void)
 529 {
 530         static unsigned long long ctr = 1;
 531         unsigned long long val;
 532         spin_lock(&fuse_lock);
 533         val = ctr++;
 534         spin_unlock(&fuse_lock);
 535         return val;
 536 }
 537
 538 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 539 {
 540         struct fuse_conn *fc;
 541         struct inode *root;
 542         struct fuse_mount_data d;
 543         struct file *file;
 544         struct dentry *root_dentry;
 545         int err;
 546
 547         if (!parse_fuse_opt((char *) data, &d))
 548                 return -EINVAL;
 549
 550         sb->s_blocksize = PAGE_CACHE_SIZE;
 551         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 552         sb->s_magic = FUSE_SUPER_MAGIC;
 553         sb->s_op = &fuse_super_operations;
 554         sb->s_maxbytes = MAX_LFS_FILESIZE;
 555
 556         file = fget(d.fd);
 557         if (!file)
 558                 return -EINVAL;
 559
 560         fc = get_conn(file, sb);
 561         fput(file);
 562         if (IS_ERR(fc))
 563                 return PTR_ERR(fc);
 564
 565         fc->flags = d.flags;
 566         fc->user_id = d.user_id;
 567         fc->group_id = d.group_id;
 568         fc->max_read = d.max_read;
 569
 570         /* Used by get_root_inode() */
 571         sb->s_fs_info = fc;
 572
 573         err = -ENOMEM;
 574         root = get_root_inode(sb, d.rootmode);
 575         if (!root)
 576                 goto err;
 577
 578         root_dentry = d_alloc_root(root);
 579         if (!root_dentry) {
 580                 iput(root);
 581                 goto err;
 582         }
 583
 584         err = kobject_set_name(&fc->kobj, "%llu", conn_id());
 585         if (err)
 586                 goto err_put_root;
 587
 588         err = kobject_add(&fc->kobj);
 589         if (err)
 590                 goto err_put_root;
 591
 592         sb->s_root = root_dentry;
 593         spin_lock(&fuse_lock);
 594         fc->mounted = 1;
 595         fc->connected = 1;
 596         spin_unlock(&fuse_lock);
 597
 598         fuse_send_init(fc);
 599
 600         return 0;
 601
 602  err_put_root:
 603         dput(root_dentry);
 604  err:
 605         kobject_put(&fc->kobj);
 606         return err;
 607 }
 608
 609 static struct super_block *fuse_get_sb(struct file_system_type *fs_type,
 610                                        int flags, const char *dev_name,
 611                                        void *raw_data)
 612 {
 613         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super);
 614 }
 615
 616 static struct file_system_type fuse_fs_type = {
 617         .owner          = THIS_MODULE,
 618         .name           = "fuse",
 619         .get_sb         = fuse_get_sb,
 620         .kill_sb        = kill_anon_super,
 621 };
 622
 623 static ssize_t fuse_conn_waiting_show(struct fuse_conn *fc, char *page)
 624 {
 625         return sprintf(page, "%i\n", atomic_read(&fc->num_waiting));
 626 }
 627
 628 static ssize_t fuse_conn_abort_store(struct fuse_conn *fc, const char *page,
 629                                      size_t count)
 630 {
 631         fuse_abort_conn(fc);
 632         return count;
 633 }
 634
 635 static struct fuse_conn_attr fuse_conn_waiting =
 636         __ATTR(waiting, 0400, fuse_conn_waiting_show, NULL);
 637 static struct fuse_conn_attr fuse_conn_abort =
 638         __ATTR(abort, 0600, NULL, fuse_conn_abort_store);
 639
 640 static struct attribute *fuse_conn_attrs[] = {
 641         &fuse_conn_waiting.attr,
 642         &fuse_conn_abort.attr,
 643         NULL,
 644 };
 645
 646 static ssize_t fuse_conn_attr_show(struct kobject *kobj,
 647                                    struct attribute *attr,
 648                                    char *page)
 649 {
 650         struct fuse_conn_attr *fca =
 651                 container_of(attr, struct fuse_conn_attr, attr);
 652
 653         if (fca->show)
 654                 return fca->show(get_fuse_conn_kobj(kobj), page);
 655         else
 656                 return -EACCES;
 657 }
 658
 659 static ssize_t fuse_conn_attr_store(struct kobject *kobj,
 660                                     struct attribute *attr,
 661                                     const char *page, size_t count)
 662 {
 663         struct fuse_conn_attr *fca =
 664                 container_of(attr, struct fuse_conn_attr, attr);
 665
 666         if (fca->store)
 667                 return fca->store(get_fuse_conn_kobj(kobj), page, count);
 668         else
 669                 return -EACCES;
 670 }
 671
 672 static struct sysfs_ops fuse_conn_sysfs_ops = {
 673         .show   = &fuse_conn_attr_show,
 674         .store  = &fuse_conn_attr_store,
 675 };
 676
 677 static struct kobj_type ktype_fuse_conn = {
 678         .release        = fuse_conn_release,
 679         .sysfs_ops      = &fuse_conn_sysfs_ops,
 680         .default_attrs  = fuse_conn_attrs,
 681 };
 682
 683 static decl_subsys(fuse, NULL, NULL);
 684 static decl_subsys(connections, &ktype_fuse_conn, NULL);
 685
 686 static void fuse_inode_init_once(void *foo, kmem_cache_t *cachep,
 687                                  unsigned long flags)
 688 {
 689         struct inode * inode = foo;
 690
 691         if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
 692             SLAB_CTOR_CONSTRUCTOR)
 693                 inode_init_once(inode);
 694 }
 695
 696 static int __init fuse_fs_init(void)
 697 {
 698         int err;
 699
 700         err = register_filesystem(&fuse_fs_type);
 701         if (err)
 702                 printk("fuse: failed to register filesystem\n");
 703         else {
 704                 fuse_inode_cachep = kmem_cache_create("fuse_inode",
 705                                                       sizeof(struct fuse_inode),
 706                                                       0, SLAB_HWCACHE_ALIGN,
 707                                                       fuse_inode_init_once, NULL);
 708                 if (!fuse_inode_cachep) {
 709                         unregister_filesystem(&fuse_fs_type);
 710                         err = -ENOMEM;
 711                 }
 712         }
 713
 714         return err;
 715 }
 716
 717 static void fuse_fs_cleanup(void)
 718 {
 719         unregister_filesystem(&fuse_fs_type);
 720         kmem_cache_destroy(fuse_inode_cachep);
 721 }
 722
 723 static int fuse_sysfs_init(void)
 724 {
 725         int err;
 726
 727         kset_set_kset_s(&fuse_subsys, fs_subsys);
 728         err = subsystem_register(&fuse_subsys);
 729         if (err)
 730                 goto out_err;
 731
 732         kset_set_kset_s(&connections_subsys, fuse_subsys);
 733         err = subsystem_register(&connections_subsys);
 734         if (err)
 735                 goto out_fuse_unregister;
 736
 737         return 0;
 738
 739  out_fuse_unregister:
 740         subsystem_unregister(&fuse_subsys);
 741  out_err:
 742         return err;
 743 }
 744
 745 static void fuse_sysfs_cleanup(void)
 746 {
 747         subsystem_unregister(&connections_subsys);
 748         subsystem_unregister(&fuse_subsys);
 749 }
 750
 751 static int __init fuse_init(void)
 752 {
 753         int res;
 754
 755         printk("fuse init (API version %i.%i)\n",
 756                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 757
 758         spin_lock_init(&fuse_lock);
 759         res = fuse_fs_init();
 760         if (res)
 761                 goto err;
 762
 763         res = fuse_dev_init();
 764         if (res)
 765                 goto err_fs_cleanup;
 766
 767         res = fuse_sysfs_init();
 768         if (res)
 769                 goto err_dev_cleanup;
 770
 771         return 0;
 772
 773  err_dev_cleanup:
 774         fuse_dev_cleanup();
 775  err_fs_cleanup:
 776         fuse_fs_cleanup();
 777  err:
 778         return res;
 779 }
 780
 781 static void __exit fuse_exit(void)
 782 {
 783         printk(KERN_DEBUG "fuse exit\n");
 784
 785         fuse_sysfs_cleanup();
 786         fuse_fs_cleanup();
 787         fuse_dev_cleanup();
 788 }
 789
 790 module_init(fuse_init);
 791 module_exit(fuse_exit);