fs/fuse/inode.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU GPL.
   6   See the file COPYING.
   7 */
   8
   9 #include "fuse_i.h"
  10
  11 #include <linux/pagemap.h>
  12 #include <linux/slab.h>
  13 #include <linux/file.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/init.h>
  16 #include <linux/module.h>
  17 #include <linux/parser.h>
  18 #include <linux/statfs.h>
  19 #include <linux/random.h>
  20 #include <linux/sched.h>
  21
  22 MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
  23 MODULE_DESCRIPTION("Filesystem in Userspace");
  24 MODULE_LICENSE("GPL");
  25
  26 static struct kmem_cache *fuse_inode_cachep;
  27 struct list_head fuse_conn_list;
  28 DEFINE_MUTEX(fuse_mutex);
  29
  30 #define FUSE_SUPER_MAGIC 0x65735546
  31
  32 struct fuse_mount_data {
  33         int fd;
  34         unsigned rootmode;
  35         unsigned user_id;
  36         unsigned group_id;
  37         unsigned fd_present : 1;
  38         unsigned rootmode_present : 1;
  39         unsigned user_id_present : 1;
  40         unsigned group_id_present : 1;
  41         unsigned flags;
  42         unsigned max_read;
  43         unsigned blksize;
  44 };
  45
  46 static struct inode *fuse_alloc_inode(struct super_block *sb)
  47 {
  48         struct inode *inode;
  49         struct fuse_inode *fi;
  50
  51         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
  52         if (!inode)
  53                 return NULL;
  54
  55         fi = get_fuse_inode(inode);
  56         fi->i_time = 0;
  57         fi->nodeid = 0;
  58         fi->nlookup = 0;
  59         INIT_LIST_HEAD(&fi->write_files);
  60         fi->forget_req = fuse_request_alloc();
  61         if (!fi->forget_req) {
  62                 kmem_cache_free(fuse_inode_cachep, inode);
  63                 return NULL;
  64         }
  65
  66         return inode;
  67 }
  68
  69 static void fuse_destroy_inode(struct inode *inode)
  70 {
  71         struct fuse_inode *fi = get_fuse_inode(inode);
  72         BUG_ON(!list_empty(&fi->write_files));
  73         if (fi->forget_req)
  74                 fuse_request_free(fi->forget_req);
  75         kmem_cache_free(fuse_inode_cachep, inode);
  76 }
  77
  78 static void fuse_read_inode(struct inode *inode)
  79 {
  80         /* No op */
  81 }
  82
  83 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
  84                       unsigned long nodeid, u64 nlookup)
  85 {
  86         struct fuse_forget_in *inarg = &req->misc.forget_in;
  87         inarg->nlookup = nlookup;
  88         req->in.h.opcode = FUSE_FORGET;
  89         req->in.h.nodeid = nodeid;
  90         req->in.numargs = 1;
  91         req->in.args[0].size = sizeof(struct fuse_forget_in);
  92         req->in.args[0].value = inarg;
  93         request_send_noreply(fc, req);
  94 }
  95
  96 static void fuse_clear_inode(struct inode *inode)
  97 {
  98         if (inode->i_sb->s_flags & MS_ACTIVE) {
  99                 struct fuse_conn *fc = get_fuse_conn(inode);
 100                 struct fuse_inode *fi = get_fuse_inode(inode);
 101                 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
 102                 fi->forget_req = NULL;
 103         }
 104 }
 105
 106 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
 107 {
 108         if (*flags & MS_MANDLOCK)
 109                 return -EINVAL;
 110
 111         return 0;
 112 }
 113
 114 static void fuse_truncate(struct address_space *mapping, loff_t offset)
 115 {
 116         /* See vmtruncate() */
 117         unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
 118         truncate_inode_pages(mapping, offset);
 119         unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1);
 120 }
 121
 122
 123 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 124                             u64 attr_valid, u64 attr_version)
 125 {
 126         struct fuse_conn *fc = get_fuse_conn(inode);
 127         struct fuse_inode *fi = get_fuse_inode(inode);
 128         loff_t oldsize;
 129
 130         spin_lock(&fc->lock);
 131         if (attr_version != 0 && fi->attr_version > attr_version) {
 132                 spin_unlock(&fc->lock);
 133                 return;
 134         }
 135         fi->attr_version = ++fc->attr_version;
 136         fi->i_time = attr_valid;
 137
 138         inode->i_ino     = attr->ino;
 139         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 140         inode->i_nlink   = attr->nlink;
 141         inode->i_uid     = attr->uid;
 142         inode->i_gid     = attr->gid;
 143         inode->i_blocks  = attr->blocks;
 144         inode->i_atime.tv_sec   = attr->atime;
 145         inode->i_atime.tv_nsec  = attr->atimensec;
 146         inode->i_mtime.tv_sec   = attr->mtime;
 147         inode->i_mtime.tv_nsec  = attr->mtimensec;
 148         inode->i_ctime.tv_sec   = attr->ctime;
 149         inode->i_ctime.tv_nsec  = attr->ctimensec;
 150
 151         if (attr->blksize != 0)
 152                 inode->i_blkbits = ilog2(attr->blksize);
 153         else
 154                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
 155
 156         /*
 157          * Don't set the sticky bit in i_mode, unless we want the VFS
 158          * to check permissions.  This prevents failures due to the
 159          * check in may_delete().
 160          */
 161         fi->orig_i_mode = inode->i_mode;
 162         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
 163                 inode->i_mode &= ~S_ISVTX;
 164
 165         oldsize = inode->i_size;
 166         i_size_write(inode, attr->size);
 167         spin_unlock(&fc->lock);
 168
 169         if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
 170                 if (attr->size < oldsize)
 171                         fuse_truncate(inode->i_mapping, attr->size);
 172                 invalidate_inode_pages2(inode->i_mapping);
 173         }
 174 }
 175
 176 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 177 {
 178         inode->i_mode = attr->mode & S_IFMT;
 179         inode->i_size = attr->size;
 180         if (S_ISREG(inode->i_mode)) {
 181                 fuse_init_common(inode);
 182                 fuse_init_file_inode(inode);
 183         } else if (S_ISDIR(inode->i_mode))
 184                 fuse_init_dir(inode);
 185         else if (S_ISLNK(inode->i_mode))
 186                 fuse_init_symlink(inode);
 187         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 188                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 189                 fuse_init_common(inode);
 190                 init_special_inode(inode, inode->i_mode,
 191                                    new_decode_dev(attr->rdev));
 192         } else
 193                 BUG();
 194 }
 195
 196 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 197 {
 198         unsigned long nodeid = *(unsigned long *) _nodeidp;
 199         if (get_node_id(inode) == nodeid)
 200                 return 1;
 201         else
 202                 return 0;
 203 }
 204
 205 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 206 {
 207         unsigned long nodeid = *(unsigned long *) _nodeidp;
 208         get_fuse_inode(inode)->nodeid = nodeid;
 209         return 0;
 210 }
 211
 212 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 213                         int generation, struct fuse_attr *attr,
 214                         u64 attr_valid, u64 attr_version)
 215 {
 216         struct inode *inode;
 217         struct fuse_inode *fi;
 218         struct fuse_conn *fc = get_fuse_conn_super(sb);
 219
 220  retry:
 221         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 222         if (!inode)
 223                 return NULL;
 224
 225         if ((inode->i_state & I_NEW)) {
 226                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
 227                 inode->i_generation = generation;
 228                 inode->i_data.backing_dev_info = &fc->bdi;
 229                 fuse_init_inode(inode, attr);
 230                 unlock_new_inode(inode);
 231         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 232                 /* Inode has changed type, any I/O on the old should fail */
 233                 make_bad_inode(inode);
 234                 iput(inode);
 235                 goto retry;
 236         }
 237
 238         fi = get_fuse_inode(inode);
 239         spin_lock(&fc->lock);
 240         fi->nlookup ++;
 241         spin_unlock(&fc->lock);
 242         fuse_change_attributes(inode, attr, attr_valid, attr_version);
 243
 244         return inode;
 245 }
 246
 247 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
 248 {
 249         if (flags & MNT_FORCE)
 250                 fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
 251 }
 252
 253 static void fuse_send_destroy(struct fuse_conn *fc)
 254 {
 255         struct fuse_req *req = fc->destroy_req;
 256         if (req && fc->conn_init) {
 257                 fc->destroy_req = NULL;
 258                 req->in.h.opcode = FUSE_DESTROY;
 259                 req->force = 1;
 260                 request_send(fc, req);
 261                 fuse_put_request(fc, req);
 262         }
 263 }
 264
 265 static void fuse_put_super(struct super_block *sb)
 266 {
 267         struct fuse_conn *fc = get_fuse_conn_super(sb);
 268
 269         fuse_send_destroy(fc);
 270         spin_lock(&fc->lock);
 271         fc->connected = 0;
 272         fc->blocked = 0;
 273         spin_unlock(&fc->lock);
 274         /* Flush all readers on this fs */
 275         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 276         wake_up_all(&fc->waitq);
 277         wake_up_all(&fc->blocked_waitq);
 278         wake_up_all(&fc->reserved_req_waitq);
 279         mutex_lock(&fuse_mutex);
 280         list_del(&fc->entry);
 281         fuse_ctl_remove_conn(fc);
 282         mutex_unlock(&fuse_mutex);
 283         fuse_conn_put(fc);
 284 }
 285
 286 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 287 {
 288         stbuf->f_type    = FUSE_SUPER_MAGIC;
 289         stbuf->f_bsize   = attr->bsize;
 290         stbuf->f_frsize  = attr->frsize;
 291         stbuf->f_blocks  = attr->blocks;
 292         stbuf->f_bfree   = attr->bfree;
 293         stbuf->f_bavail  = attr->bavail;
 294         stbuf->f_files   = attr->files;
 295         stbuf->f_ffree   = attr->ffree;
 296         stbuf->f_namelen = attr->namelen;
 297         /* fsid is left zero */
 298 }
 299
 300 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 301 {
 302         struct super_block *sb = dentry->d_sb;
 303         struct fuse_conn *fc = get_fuse_conn_super(sb);
 304         struct fuse_req *req;
 305         struct fuse_statfs_out outarg;
 306         int err;
 307
 308         if (!fuse_allow_task(fc, current)) {
 309                 buf->f_type = FUSE_SUPER_MAGIC;
 310                 return 0;
 311         }
 312
 313         req = fuse_get_req(fc);
 314         if (IS_ERR(req))
 315                 return PTR_ERR(req);
 316
 317         memset(&outarg, 0, sizeof(outarg));
 318         req->in.numargs = 0;
 319         req->in.h.opcode = FUSE_STATFS;
 320         req->in.h.nodeid = get_node_id(dentry->d_inode);
 321         req->out.numargs = 1;
 322         req->out.args[0].size =
 323                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 324         req->out.args[0].value = &outarg;
 325         request_send(fc, req);
 326         err = req->out.h.error;
 327         if (!err)
 328                 convert_fuse_statfs(buf, &outarg.st);
 329         fuse_put_request(fc, req);
 330         return err;
 331 }
 332
 333 enum {
 334         OPT_FD,
 335         OPT_ROOTMODE,
 336         OPT_USER_ID,
 337         OPT_GROUP_ID,
 338         OPT_DEFAULT_PERMISSIONS,
 339         OPT_ALLOW_OTHER,
 340         OPT_MAX_READ,
 341         OPT_BLKSIZE,
 342         OPT_ERR
 343 };
 344
 345 static match_table_t tokens = {
 346         {OPT_FD,                        "fd=%u"},
 347         {OPT_ROOTMODE,                  "rootmode=%o"},
 348         {OPT_USER_ID,                   "user_id=%u"},
 349         {OPT_GROUP_ID,                  "group_id=%u"},
 350         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 351         {OPT_ALLOW_OTHER,               "allow_other"},
 352         {OPT_MAX_READ,                  "max_read=%u"},
 353         {OPT_BLKSIZE,                   "blksize=%u"},
 354         {OPT_ERR,                       NULL}
 355 };
 356
 357 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 358 {
 359         char *p;
 360         memset(d, 0, sizeof(struct fuse_mount_data));
 361         d->max_read = ~0;
 362         d->blksize = 512;
 363
 364         while ((p = strsep(&opt, ",")) != NULL) {
 365                 int token;
 366                 int value;
 367                 substring_t args[MAX_OPT_ARGS];
 368                 if (!*p)
 369                         continue;
 370
 371                 token = match_token(p, tokens, args);
 372                 switch (token) {
 373                 case OPT_FD:
 374                         if (match_int(&args[0], &value))
 375                                 return 0;
 376                         d->fd = value;
 377                         d->fd_present = 1;
 378                         break;
 379
 380                 case OPT_ROOTMODE:
 381                         if (match_octal(&args[0], &value))
 382                                 return 0;
 383                         if (!fuse_valid_type(value))
 384                                 return 0;
 385                         d->rootmode = value;
 386                         d->rootmode_present = 1;
 387                         break;
 388
 389                 case OPT_USER_ID:
 390                         if (match_int(&args[0], &value))
 391                                 return 0;
 392                         d->user_id = value;
 393                         d->user_id_present = 1;
 394                         break;
 395
 396                 case OPT_GROUP_ID:
 397                         if (match_int(&args[0], &value))
 398                                 return 0;
 399                         d->group_id = value;
 400                         d->group_id_present = 1;
 401                         break;
 402
 403                 case OPT_DEFAULT_PERMISSIONS:
 404                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 405                         break;
 406
 407                 case OPT_ALLOW_OTHER:
 408                         d->flags |= FUSE_ALLOW_OTHER;
 409                         break;
 410
 411                 case OPT_MAX_READ:
 412                         if (match_int(&args[0], &value))
 413                                 return 0;
 414                         d->max_read = value;
 415                         break;
 416
 417                 case OPT_BLKSIZE:
 418                         if (!is_bdev || match_int(&args[0], &value))
 419                                 return 0;
 420                         d->blksize = value;
 421                         break;
 422
 423                 default:
 424                         return 0;
 425                 }
 426         }
 427
 428         if (!d->fd_present || !d->rootmode_present ||
 429             !d->user_id_present || !d->group_id_present)
 430                 return 0;
 431
 432         return 1;
 433 }
 434
 435 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 436 {
 437         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 438
 439         seq_printf(m, ",user_id=%u", fc->user_id);
 440         seq_printf(m, ",group_id=%u", fc->group_id);
 441         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 442                 seq_puts(m, ",default_permissions");
 443         if (fc->flags & FUSE_ALLOW_OTHER)
 444                 seq_puts(m, ",allow_other");
 445         if (fc->max_read != ~0)
 446                 seq_printf(m, ",max_read=%u", fc->max_read);
 447         return 0;
 448 }
 449
 450 static struct fuse_conn *new_conn(void)
 451 {
 452         struct fuse_conn *fc;
 453         int err;
 454
 455         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 456         if (fc) {
 457                 spin_lock_init(&fc->lock);
 458                 mutex_init(&fc->inst_mutex);
 459                 atomic_set(&fc->count, 1);
 460                 init_waitqueue_head(&fc->waitq);
 461                 init_waitqueue_head(&fc->blocked_waitq);
 462                 init_waitqueue_head(&fc->reserved_req_waitq);
 463                 INIT_LIST_HEAD(&fc->pending);
 464                 INIT_LIST_HEAD(&fc->processing);
 465                 INIT_LIST_HEAD(&fc->io);
 466                 INIT_LIST_HEAD(&fc->interrupts);
 467                 atomic_set(&fc->num_waiting, 0);
 468                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 469                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 470                 err = bdi_init(&fc->bdi);
 471                 if (err) {
 472                         kfree(fc);
 473                         fc = NULL;
 474                         goto out;
 475                 }
 476                 fc->reqctr = 0;
 477                 fc->blocked = 1;
 478                 fc->attr_version = 1;
 479                 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 480         }
 481 out:
 482         return fc;
 483 }
 484
 485 void fuse_conn_put(struct fuse_conn *fc)
 486 {
 487         if (atomic_dec_and_test(&fc->count)) {
 488                 if (fc->destroy_req)
 489                         fuse_request_free(fc->destroy_req);
 490                 mutex_destroy(&fc->inst_mutex);
 491                 bdi_destroy(&fc->bdi);
 492                 kfree(fc);
 493         }
 494 }
 495
 496 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 497 {
 498         atomic_inc(&fc->count);
 499         return fc;
 500 }
 501
 502 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 503 {
 504         struct fuse_attr attr;
 505         memset(&attr, 0, sizeof(attr));
 506
 507         attr.mode = mode;
 508         attr.ino = FUSE_ROOT_ID;
 509         attr.nlink = 1;
 510         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 511 }
 512
 513 static const struct super_operations fuse_super_operations = {
 514         .alloc_inode    = fuse_alloc_inode,
 515         .destroy_inode  = fuse_destroy_inode,
 516         .read_inode     = fuse_read_inode,
 517         .clear_inode    = fuse_clear_inode,
 518         .drop_inode     = generic_delete_inode,
 519         .remount_fs     = fuse_remount_fs,
 520         .put_super      = fuse_put_super,
 521         .umount_begin   = fuse_umount_begin,
 522         .statfs         = fuse_statfs,
 523         .show_options   = fuse_show_options,
 524 };
 525
 526 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 527 {
 528         struct fuse_init_out *arg = &req->misc.init_out;
 529
 530         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 531                 fc->conn_error = 1;
 532         else {
 533                 unsigned long ra_pages;
 534
 535                 if (arg->minor >= 6) {
 536                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 537                         if (arg->flags & FUSE_ASYNC_READ)
 538                                 fc->async_read = 1;
 539                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 540                                 fc->no_lock = 1;
 541                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 542                                 fc->atomic_o_trunc = 1;
 543                 } else {
 544                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 545                         fc->no_lock = 1;
 546                 }
 547
 548                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 549                 fc->minor = arg->minor;
 550                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 551                 fc->conn_init = 1;
 552         }
 553         fuse_put_request(fc, req);
 554         fc->blocked = 0;
 555         wake_up_all(&fc->blocked_waitq);
 556 }
 557
 558 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 559 {
 560         struct fuse_init_in *arg = &req->misc.init_in;
 561
 562         arg->major = FUSE_KERNEL_VERSION;
 563         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 564         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 565         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_FILE_OPS |
 566                 FUSE_ATOMIC_O_TRUNC;
 567         req->in.h.opcode = FUSE_INIT;
 568         req->in.numargs = 1;
 569         req->in.args[0].size = sizeof(*arg);
 570         req->in.args[0].value = arg;
 571         req->out.numargs = 1;
 572         /* Variable length arguement used for backward compatibility
 573            with interface version < 7.5.  Rest of init_out is zeroed
 574            by do_get_request(), so a short reply is not a problem */
 575         req->out.argvar = 1;
 576         req->out.args[0].size = sizeof(struct fuse_init_out);
 577         req->out.args[0].value = &req->misc.init_out;
 578         req->end = process_init_reply;
 579         request_send_background(fc, req);
 580 }
 581
 582 static u64 conn_id(void)
 583 {
 584         static u64 ctr = 1;
 585         return ctr++;
 586 }
 587
 588 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 589 {
 590         struct fuse_conn *fc;
 591         struct inode *root;
 592         struct fuse_mount_data d;
 593         struct file *file;
 594         struct dentry *root_dentry;
 595         struct fuse_req *init_req;
 596         int err;
 597         int is_bdev = sb->s_bdev != NULL;
 598
 599         if (sb->s_flags & MS_MANDLOCK)
 600                 return -EINVAL;
 601
 602         if (!parse_fuse_opt((char *) data, &d, is_bdev))
 603                 return -EINVAL;
 604
 605         if (is_bdev) {
 606 #ifdef CONFIG_BLOCK
 607                 if (!sb_set_blocksize(sb, d.blksize))
 608                         return -EINVAL;
 609 #endif
 610         } else {
 611                 sb->s_blocksize = PAGE_CACHE_SIZE;
 612                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 613         }
 614         sb->s_magic = FUSE_SUPER_MAGIC;
 615         sb->s_op = &fuse_super_operations;
 616         sb->s_maxbytes = MAX_LFS_FILESIZE;
 617
 618         file = fget(d.fd);
 619         if (!file)
 620                 return -EINVAL;
 621
 622         if (file->f_op != &fuse_dev_operations)
 623                 return -EINVAL;
 624
 625         fc = new_conn();
 626         if (!fc)
 627                 return -ENOMEM;
 628
 629         fc->flags = d.flags;
 630         fc->user_id = d.user_id;
 631         fc->group_id = d.group_id;
 632         fc->max_read = d.max_read;
 633
 634         /* Used by get_root_inode() */
 635         sb->s_fs_info = fc;
 636
 637         err = -ENOMEM;
 638         root = get_root_inode(sb, d.rootmode);
 639         if (!root)
 640                 goto err;
 641
 642         root_dentry = d_alloc_root(root);
 643         if (!root_dentry) {
 644                 iput(root);
 645                 goto err;
 646         }
 647
 648         init_req = fuse_request_alloc();
 649         if (!init_req)
 650                 goto err_put_root;
 651
 652         if (is_bdev) {
 653                 fc->destroy_req = fuse_request_alloc();
 654                 if (!fc->destroy_req)
 655                         goto err_put_root;
 656         }
 657
 658         mutex_lock(&fuse_mutex);
 659         err = -EINVAL;
 660         if (file->private_data)
 661                 goto err_unlock;
 662
 663         fc->id = conn_id();
 664         err = fuse_ctl_add_conn(fc);
 665         if (err)
 666                 goto err_unlock;
 667
 668         list_add_tail(&fc->entry, &fuse_conn_list);
 669         sb->s_root = root_dentry;
 670         fc->connected = 1;
 671         file->private_data = fuse_conn_get(fc);
 672         mutex_unlock(&fuse_mutex);
 673         /*
 674          * atomic_dec_and_test() in fput() provides the necessary
 675          * memory barrier for file->private_data to be visible on all
 676          * CPUs after this
 677          */
 678         fput(file);
 679
 680         fuse_send_init(fc, init_req);
 681
 682         return 0;
 683
 684  err_unlock:
 685         mutex_unlock(&fuse_mutex);
 686         fuse_request_free(init_req);
 687  err_put_root:
 688         dput(root_dentry);
 689  err:
 690         fput(file);
 691         fuse_conn_put(fc);
 692         return err;
 693 }
 694
 695 static int fuse_get_sb(struct file_system_type *fs_type,
 696                        int flags, const char *dev_name,
 697                        void *raw_data, struct vfsmount *mnt)
 698 {
 699         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 700 }
 701
 702 static struct file_system_type fuse_fs_type = {
 703         .owner          = THIS_MODULE,
 704         .name           = "fuse",
 705         .fs_flags       = FS_HAS_SUBTYPE,
 706         .get_sb         = fuse_get_sb,
 707         .kill_sb        = kill_anon_super,
 708 };
 709
 710 #ifdef CONFIG_BLOCK
 711 static int fuse_get_sb_blk(struct file_system_type *fs_type,
 712                            int flags, const char *dev_name,
 713                            void *raw_data, struct vfsmount *mnt)
 714 {
 715         return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
 716                            mnt);
 717 }
 718
 719 static struct file_system_type fuseblk_fs_type = {
 720         .owner          = THIS_MODULE,
 721         .name           = "fuseblk",
 722         .get_sb         = fuse_get_sb_blk,
 723         .kill_sb        = kill_block_super,
 724         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
 725 };
 726
 727 static inline int register_fuseblk(void)
 728 {
 729         return register_filesystem(&fuseblk_fs_type);
 730 }
 731
 732 static inline void unregister_fuseblk(void)
 733 {
 734         unregister_filesystem(&fuseblk_fs_type);
 735 }
 736 #else
 737 static inline int register_fuseblk(void)
 738 {
 739         return 0;
 740 }
 741
 742 static inline void unregister_fuseblk(void)
 743 {
 744 }
 745 #endif
 746
 747 static decl_subsys(fuse, NULL, NULL);
 748 static decl_subsys(connections, NULL, NULL);
 749
 750 static void fuse_inode_init_once(struct kmem_cache *cachep, void *foo)
 751 {
 752         struct inode * inode = foo;
 753
 754         inode_init_once(inode);
 755 }
 756
 757 static int __init fuse_fs_init(void)
 758 {
 759         int err;
 760
 761         err = register_filesystem(&fuse_fs_type);
 762         if (err)
 763                 goto out;
 764
 765         err = register_fuseblk();
 766         if (err)
 767                 goto out_unreg;
 768
 769         fuse_inode_cachep = kmem_cache_create("fuse_inode",
 770                                               sizeof(struct fuse_inode),
 771                                               0, SLAB_HWCACHE_ALIGN,
 772                                               fuse_inode_init_once);
 773         err = -ENOMEM;
 774         if (!fuse_inode_cachep)
 775                 goto out_unreg2;
 776
 777         return 0;
 778
 779  out_unreg2:
 780         unregister_fuseblk();
 781  out_unreg:
 782         unregister_filesystem(&fuse_fs_type);
 783  out:
 784         return err;
 785 }
 786
 787 static void fuse_fs_cleanup(void)
 788 {
 789         unregister_filesystem(&fuse_fs_type);
 790         unregister_fuseblk();
 791         kmem_cache_destroy(fuse_inode_cachep);
 792 }
 793
 794 static int fuse_sysfs_init(void)
 795 {
 796         int err;
 797
 798         kobj_set_kset_s(&fuse_subsys, fs_subsys);
 799         err = subsystem_register(&fuse_subsys);
 800         if (err)
 801                 goto out_err;
 802
 803         kobj_set_kset_s(&connections_subsys, fuse_subsys);
 804         err = subsystem_register(&connections_subsys);
 805         if (err)
 806                 goto out_fuse_unregister;
 807
 808         return 0;
 809
 810  out_fuse_unregister:
 811         subsystem_unregister(&fuse_subsys);
 812  out_err:
 813         return err;
 814 }
 815
 816 static void fuse_sysfs_cleanup(void)
 817 {
 818         subsystem_unregister(&connections_subsys);
 819         subsystem_unregister(&fuse_subsys);
 820 }
 821
 822 static int __init fuse_init(void)
 823 {
 824         int res;
 825
 826         printk("fuse init (API version %i.%i)\n",
 827                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 828
 829         INIT_LIST_HEAD(&fuse_conn_list);
 830         res = fuse_fs_init();
 831         if (res)
 832                 goto err;
 833
 834         res = fuse_dev_init();
 835         if (res)
 836                 goto err_fs_cleanup;
 837
 838         res = fuse_sysfs_init();
 839         if (res)
 840                 goto err_dev_cleanup;
 841
 842         res = fuse_ctl_init();
 843         if (res)
 844                 goto err_sysfs_cleanup;
 845
 846         return 0;
 847
 848  err_sysfs_cleanup:
 849         fuse_sysfs_cleanup();
 850  err_dev_cleanup:
 851         fuse_dev_cleanup();
 852  err_fs_cleanup:
 853         fuse_fs_cleanup();
 854  err:
 855         return res;
 856 }
 857
 858 static void __exit fuse_exit(void)
 859 {
 860         printk(KERN_DEBUG "fuse exit\n");
 861
 862         fuse_ctl_cleanup();
 863         fuse_sysfs_cleanup();
 864         fuse_fs_cleanup();
 865         fuse_dev_cleanup();
 866 }
 867
 868 module_init(fuse_init);
 869 module_exit(fuse_exit);