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