git.oblomov.eu Git - linux-2.6/blob - fs/fuse/inode.c

   1 /*
   2   FUSE: Filesystem in Userspace
   3   Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
   4
   5   This program can be distributed under the terms of the GNU GPL.
   6   See the file COPYING.
   7 */
   8
   9 #include "fuse_i.h"
  10
  11 #include <linux/pagemap.h>
  12 #include <linux/slab.h>
  13 #include <linux/file.h>
  14 #include <linux/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 #define FUSE_DEFAULT_BLKSIZE 512
  33
  34 struct fuse_mount_data {
  35         int fd;
  36         unsigned rootmode;
  37         unsigned user_id;
  38         unsigned group_id;
  39         unsigned fd_present : 1;
  40         unsigned rootmode_present : 1;
  41         unsigned user_id_present : 1;
  42         unsigned group_id_present : 1;
  43         unsigned flags;
  44         unsigned max_read;
  45         unsigned blksize;
  46 };
  47
  48 static struct inode *fuse_alloc_inode(struct super_block *sb)
  49 {
  50         struct inode *inode;
  51         struct fuse_inode *fi;
  52
  53         inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
  54         if (!inode)
  55                 return NULL;
  56
  57         fi = get_fuse_inode(inode);
  58         fi->i_time = 0;
  59         fi->nodeid = 0;
  60         fi->nlookup = 0;
  61         fi->attr_version = 0;
  62         INIT_LIST_HEAD(&fi->write_files);
  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         BUG_ON(!list_empty(&fi->write_files));
  76         if (fi->forget_req)
  77                 fuse_request_free(fi->forget_req);
  78         kmem_cache_free(fuse_inode_cachep, inode);
  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
 121 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 122                             u64 attr_valid, u64 attr_version)
 123 {
 124         struct fuse_conn *fc = get_fuse_conn(inode);
 125         struct fuse_inode *fi = get_fuse_inode(inode);
 126         loff_t oldsize;
 127
 128         spin_lock(&fc->lock);
 129         if (attr_version != 0 && fi->attr_version > attr_version) {
 130                 spin_unlock(&fc->lock);
 131                 return;
 132         }
 133         fi->attr_version = ++fc->attr_version;
 134         fi->i_time = attr_valid;
 135
 136         inode->i_ino     = attr->ino;
 137         inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 138         inode->i_nlink   = attr->nlink;
 139         inode->i_uid     = attr->uid;
 140         inode->i_gid     = attr->gid;
 141         inode->i_blocks  = attr->blocks;
 142         inode->i_atime.tv_sec   = attr->atime;
 143         inode->i_atime.tv_nsec  = attr->atimensec;
 144         inode->i_mtime.tv_sec   = attr->mtime;
 145         inode->i_mtime.tv_nsec  = attr->mtimensec;
 146         inode->i_ctime.tv_sec   = attr->ctime;
 147         inode->i_ctime.tv_nsec  = attr->ctimensec;
 148
 149         if (attr->blksize != 0)
 150                 inode->i_blkbits = ilog2(attr->blksize);
 151         else
 152                 inode->i_blkbits = inode->i_sb->s_blocksize_bits;
 153
 154         /*
 155          * Don't set the sticky bit in i_mode, unless we want the VFS
 156          * to check permissions.  This prevents failures due to the
 157          * check in may_delete().
 158          */
 159         fi->orig_i_mode = inode->i_mode;
 160         if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
 161                 inode->i_mode &= ~S_ISVTX;
 162
 163         oldsize = inode->i_size;
 164         i_size_write(inode, attr->size);
 165         spin_unlock(&fc->lock);
 166
 167         if (S_ISREG(inode->i_mode) && oldsize != attr->size) {
 168                 if (attr->size < oldsize)
 169                         fuse_truncate(inode->i_mapping, attr->size);
 170                 invalidate_inode_pages2(inode->i_mapping);
 171         }
 172 }
 173
 174 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
 175 {
 176         inode->i_mode = attr->mode & S_IFMT;
 177         inode->i_size = attr->size;
 178         if (S_ISREG(inode->i_mode)) {
 179                 fuse_init_common(inode);
 180                 fuse_init_file_inode(inode);
 181         } else if (S_ISDIR(inode->i_mode))
 182                 fuse_init_dir(inode);
 183         else if (S_ISLNK(inode->i_mode))
 184                 fuse_init_symlink(inode);
 185         else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 186                  S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 187                 fuse_init_common(inode);
 188                 init_special_inode(inode, inode->i_mode,
 189                                    new_decode_dev(attr->rdev));
 190         } else
 191                 BUG();
 192 }
 193
 194 static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
 195 {
 196         unsigned long nodeid = *(unsigned long *) _nodeidp;
 197         if (get_node_id(inode) == nodeid)
 198                 return 1;
 199         else
 200                 return 0;
 201 }
 202
 203 static int fuse_inode_set(struct inode *inode, void *_nodeidp)
 204 {
 205         unsigned long nodeid = *(unsigned long *) _nodeidp;
 206         get_fuse_inode(inode)->nodeid = nodeid;
 207         return 0;
 208 }
 209
 210 struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
 211                         int generation, struct fuse_attr *attr,
 212                         u64 attr_valid, u64 attr_version)
 213 {
 214         struct inode *inode;
 215         struct fuse_inode *fi;
 216         struct fuse_conn *fc = get_fuse_conn_super(sb);
 217
 218  retry:
 219         inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 220         if (!inode)
 221                 return NULL;
 222
 223         if ((inode->i_state & I_NEW)) {
 224                 inode->i_flags |= S_NOATIME|S_NOCMTIME;
 225                 inode->i_generation = generation;
 226                 inode->i_data.backing_dev_info = &fc->bdi;
 227                 fuse_init_inode(inode, attr);
 228                 unlock_new_inode(inode);
 229         } else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
 230                 /* Inode has changed type, any I/O on the old should fail */
 231                 make_bad_inode(inode);
 232                 iput(inode);
 233                 goto retry;
 234         }
 235
 236         fi = get_fuse_inode(inode);
 237         spin_lock(&fc->lock);
 238         fi->nlookup ++;
 239         spin_unlock(&fc->lock);
 240         fuse_change_attributes(inode, attr, attr_valid, attr_version);
 241
 242         return inode;
 243 }
 244
 245 static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
 246 {
 247         if (flags & MNT_FORCE)
 248                 fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
 249 }
 250
 251 static void fuse_send_destroy(struct fuse_conn *fc)
 252 {
 253         struct fuse_req *req = fc->destroy_req;
 254         if (req && fc->conn_init) {
 255                 fc->destroy_req = NULL;
 256                 req->in.h.opcode = FUSE_DESTROY;
 257                 req->force = 1;
 258                 request_send(fc, req);
 259                 fuse_put_request(fc, req);
 260         }
 261 }
 262
 263 static void fuse_put_super(struct super_block *sb)
 264 {
 265         struct fuse_conn *fc = get_fuse_conn_super(sb);
 266
 267         fuse_send_destroy(fc);
 268         spin_lock(&fc->lock);
 269         fc->connected = 0;
 270         fc->blocked = 0;
 271         spin_unlock(&fc->lock);
 272         /* Flush all readers on this fs */
 273         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 274         wake_up_all(&fc->waitq);
 275         wake_up_all(&fc->blocked_waitq);
 276         wake_up_all(&fc->reserved_req_waitq);
 277         mutex_lock(&fuse_mutex);
 278         list_del(&fc->entry);
 279         fuse_ctl_remove_conn(fc);
 280         mutex_unlock(&fuse_mutex);
 281         fuse_conn_put(fc);
 282 }
 283
 284 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 285 {
 286         stbuf->f_type    = FUSE_SUPER_MAGIC;
 287         stbuf->f_bsize   = attr->bsize;
 288         stbuf->f_frsize  = attr->frsize;
 289         stbuf->f_blocks  = attr->blocks;
 290         stbuf->f_bfree   = attr->bfree;
 291         stbuf->f_bavail  = attr->bavail;
 292         stbuf->f_files   = attr->files;
 293         stbuf->f_ffree   = attr->ffree;
 294         stbuf->f_namelen = attr->namelen;
 295         /* fsid is left zero */
 296 }
 297
 298 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 299 {
 300         struct super_block *sb = dentry->d_sb;
 301         struct fuse_conn *fc = get_fuse_conn_super(sb);
 302         struct fuse_req *req;
 303         struct fuse_statfs_out outarg;
 304         int err;
 305
 306         if (!fuse_allow_task(fc, current)) {
 307                 buf->f_type = FUSE_SUPER_MAGIC;
 308                 return 0;
 309         }
 310
 311         req = fuse_get_req(fc);
 312         if (IS_ERR(req))
 313                 return PTR_ERR(req);
 314
 315         memset(&outarg, 0, sizeof(outarg));
 316         req->in.numargs = 0;
 317         req->in.h.opcode = FUSE_STATFS;
 318         req->in.h.nodeid = get_node_id(dentry->d_inode);
 319         req->out.numargs = 1;
 320         req->out.args[0].size =
 321                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 322         req->out.args[0].value = &outarg;
 323         request_send(fc, req);
 324         err = req->out.h.error;
 325         if (!err)
 326                 convert_fuse_statfs(buf, &outarg.st);
 327         fuse_put_request(fc, req);
 328         return err;
 329 }
 330
 331 enum {
 332         OPT_FD,
 333         OPT_ROOTMODE,
 334         OPT_USER_ID,
 335         OPT_GROUP_ID,
 336         OPT_DEFAULT_PERMISSIONS,
 337         OPT_ALLOW_OTHER,
 338         OPT_MAX_READ,
 339         OPT_BLKSIZE,
 340         OPT_ERR
 341 };
 342
 343 static match_table_t tokens = {
 344         {OPT_FD,                        "fd=%u"},
 345         {OPT_ROOTMODE,                  "rootmode=%o"},
 346         {OPT_USER_ID,                   "user_id=%u"},
 347         {OPT_GROUP_ID,                  "group_id=%u"},
 348         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 349         {OPT_ALLOW_OTHER,               "allow_other"},
 350         {OPT_MAX_READ,                  "max_read=%u"},
 351         {OPT_BLKSIZE,                   "blksize=%u"},
 352         {OPT_ERR,                       NULL}
 353 };
 354
 355 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 356 {
 357         char *p;
 358         memset(d, 0, sizeof(struct fuse_mount_data));
 359         d->max_read = ~0;
 360         d->blksize = FUSE_DEFAULT_BLKSIZE;
 361
 362         while ((p = strsep(&opt, ",")) != NULL) {
 363                 int token;
 364                 int value;
 365                 substring_t args[MAX_OPT_ARGS];
 366                 if (!*p)
 367                         continue;
 368
 369                 token = match_token(p, tokens, args);
 370                 switch (token) {
 371                 case OPT_FD:
 372                         if (match_int(&args[0], &value))
 373                                 return 0;
 374                         d->fd = value;
 375                         d->fd_present = 1;
 376                         break;
 377
 378                 case OPT_ROOTMODE:
 379                         if (match_octal(&args[0], &value))
 380                                 return 0;
 381                         if (!fuse_valid_type(value))
 382                                 return 0;
 383                         d->rootmode = value;
 384                         d->rootmode_present = 1;
 385                         break;
 386
 387                 case OPT_USER_ID:
 388                         if (match_int(&args[0], &value))
 389                                 return 0;
 390                         d->user_id = value;
 391                         d->user_id_present = 1;
 392                         break;
 393
 394                 case OPT_GROUP_ID:
 395                         if (match_int(&args[0], &value))
 396                                 return 0;
 397                         d->group_id = value;
 398                         d->group_id_present = 1;
 399                         break;
 400
 401                 case OPT_DEFAULT_PERMISSIONS:
 402                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 403                         break;
 404
 405                 case OPT_ALLOW_OTHER:
 406                         d->flags |= FUSE_ALLOW_OTHER;
 407                         break;
 408
 409                 case OPT_MAX_READ:
 410                         if (match_int(&args[0], &value))
 411                                 return 0;
 412                         d->max_read = value;
 413                         break;
 414
 415                 case OPT_BLKSIZE:
 416                         if (!is_bdev || match_int(&args[0], &value))
 417                                 return 0;
 418                         d->blksize = value;
 419                         break;
 420
 421                 default:
 422                         return 0;
 423                 }
 424         }
 425
 426         if (!d->fd_present || !d->rootmode_present ||
 427             !d->user_id_present || !d->group_id_present)
 428                 return 0;
 429
 430         return 1;
 431 }
 432
 433 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 434 {
 435         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 436
 437         seq_printf(m, ",user_id=%u", fc->user_id);
 438         seq_printf(m, ",group_id=%u", fc->group_id);
 439         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 440                 seq_puts(m, ",default_permissions");
 441         if (fc->flags & FUSE_ALLOW_OTHER)
 442                 seq_puts(m, ",allow_other");
 443         if (fc->max_read != ~0)
 444                 seq_printf(m, ",max_read=%u", fc->max_read);
 445         if (mnt->mnt_sb->s_bdev &&
 446             mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 447                 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
 448         return 0;
 449 }
 450
 451 static struct fuse_conn *new_conn(void)
 452 {
 453         struct fuse_conn *fc;
 454         int err;
 455
 456         fc = kzalloc(sizeof(*fc), GFP_KERNEL);
 457         if (fc) {
 458                 spin_lock_init(&fc->lock);
 459                 mutex_init(&fc->inst_mutex);
 460                 atomic_set(&fc->count, 1);
 461                 init_waitqueue_head(&fc->waitq);
 462                 init_waitqueue_head(&fc->blocked_waitq);
 463                 init_waitqueue_head(&fc->reserved_req_waitq);
 464                 INIT_LIST_HEAD(&fc->pending);
 465                 INIT_LIST_HEAD(&fc->processing);
 466                 INIT_LIST_HEAD(&fc->io);
 467                 INIT_LIST_HEAD(&fc->interrupts);
 468                 INIT_LIST_HEAD(&fc->bg_queue);
 469                 atomic_set(&fc->num_waiting, 0);
 470                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 471                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 472                 err = bdi_init(&fc->bdi);
 473                 if (err) {
 474                         kfree(fc);
 475                         fc = NULL;
 476                         goto out;
 477                 }
 478                 fc->reqctr = 0;
 479                 fc->blocked = 1;
 480                 fc->attr_version = 1;
 481                 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 482         }
 483 out:
 484         return fc;
 485 }
 486
 487 void fuse_conn_put(struct fuse_conn *fc)
 488 {
 489         if (atomic_dec_and_test(&fc->count)) {
 490                 if (fc->destroy_req)
 491                         fuse_request_free(fc->destroy_req);
 492                 mutex_destroy(&fc->inst_mutex);
 493                 bdi_destroy(&fc->bdi);
 494                 kfree(fc);
 495         }
 496 }
 497
 498 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 499 {
 500         atomic_inc(&fc->count);
 501         return fc;
 502 }
 503
 504 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 505 {
 506         struct fuse_attr attr;
 507         memset(&attr, 0, sizeof(attr));
 508
 509         attr.mode = mode;
 510         attr.ino = FUSE_ROOT_ID;
 511         attr.nlink = 1;
 512         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 513 }
 514
 515 static const struct super_operations fuse_super_operations = {
 516         .alloc_inode    = fuse_alloc_inode,
 517         .destroy_inode  = fuse_destroy_inode,
 518         .clear_inode    = fuse_clear_inode,
 519         .drop_inode     = generic_delete_inode,
 520         .remount_fs     = fuse_remount_fs,
 521         .put_super      = fuse_put_super,
 522         .umount_begin   = fuse_umount_begin,
 523         .statfs         = fuse_statfs,
 524         .show_options   = fuse_show_options,
 525 };
 526
 527 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
 528 {
 529         struct fuse_init_out *arg = &req->misc.init_out;
 530
 531         if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
 532                 fc->conn_error = 1;
 533         else {
 534                 unsigned long ra_pages;
 535
 536                 if (arg->minor >= 6) {
 537                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
 538                         if (arg->flags & FUSE_ASYNC_READ)
 539                                 fc->async_read = 1;
 540                         if (!(arg->flags & FUSE_POSIX_LOCKS))
 541                                 fc->no_lock = 1;
 542                         if (arg->flags & FUSE_ATOMIC_O_TRUNC)
 543                                 fc->atomic_o_trunc = 1;
 544                 } else {
 545                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
 546                         fc->no_lock = 1;
 547                 }
 548
 549                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
 550                 fc->minor = arg->minor;
 551                 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
 552                 fc->conn_init = 1;
 553         }
 554         fuse_put_request(fc, req);
 555         fc->blocked = 0;
 556         wake_up_all(&fc->blocked_waitq);
 557 }
 558
 559 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
 560 {
 561         struct fuse_init_in *arg = &req->misc.init_in;
 562
 563         arg->major = FUSE_KERNEL_VERSION;
 564         arg->minor = FUSE_KERNEL_MINOR_VERSION;
 565         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
 566         arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | 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 void fuse_inode_init_once(struct kmem_cache *cachep, void *foo)
 748 {
 749         struct inode * inode = foo;
 750
 751         inode_init_once(inode);
 752 }
 753
 754 static int __init fuse_fs_init(void)
 755 {
 756         int err;
 757
 758         err = register_filesystem(&fuse_fs_type);
 759         if (err)
 760                 goto out;
 761
 762         err = register_fuseblk();
 763         if (err)
 764                 goto out_unreg;
 765
 766         fuse_inode_cachep = kmem_cache_create("fuse_inode",
 767                                               sizeof(struct fuse_inode),
 768                                               0, SLAB_HWCACHE_ALIGN,
 769                                               fuse_inode_init_once);
 770         err = -ENOMEM;
 771         if (!fuse_inode_cachep)
 772                 goto out_unreg2;
 773
 774         return 0;
 775
 776  out_unreg2:
 777         unregister_fuseblk();
 778  out_unreg:
 779         unregister_filesystem(&fuse_fs_type);
 780  out:
 781         return err;
 782 }
 783
 784 static void fuse_fs_cleanup(void)
 785 {
 786         unregister_filesystem(&fuse_fs_type);
 787         unregister_fuseblk();
 788         kmem_cache_destroy(fuse_inode_cachep);
 789 }
 790
 791 static struct kobject *fuse_kobj;
 792 static struct kobject *connections_kobj;
 793
 794 static int fuse_sysfs_init(void)
 795 {
 796         int err;
 797
 798         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
 799         if (!fuse_kobj) {
 800                 err = -ENOMEM;
 801                 goto out_err;
 802         }
 803
 804         connections_kobj = kobject_create_and_add("connections", fuse_kobj);
 805         if (!connections_kobj) {
 806                 err = -ENOMEM;
 807                 goto out_fuse_unregister;
 808         }
 809
 810         return 0;
 811
 812  out_fuse_unregister:
 813         kobject_put(fuse_kobj);
 814  out_err:
 815         return err;
 816 }
 817
 818 static void fuse_sysfs_cleanup(void)
 819 {
 820         kobject_put(connections_kobj);
 821         kobject_put(fuse_kobj);
 822 }
 823
 824 static int __init fuse_init(void)
 825 {
 826         int res;
 827
 828         printk("fuse init (API version %i.%i)\n",
 829                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 830
 831         INIT_LIST_HEAD(&fuse_conn_list);
 832         res = fuse_fs_init();
 833         if (res)
 834                 goto err;
 835
 836         res = fuse_dev_init();
 837         if (res)
 838                 goto err_fs_cleanup;
 839
 840         res = fuse_sysfs_init();
 841         if (res)
 842                 goto err_dev_cleanup;
 843
 844         res = fuse_ctl_init();
 845         if (res)
 846                 goto err_sysfs_cleanup;
 847
 848         return 0;
 849
 850  err_sysfs_cleanup:
 851         fuse_sysfs_cleanup();
 852  err_dev_cleanup:
 853         fuse_dev_cleanup();
 854  err_fs_cleanup:
 855         fuse_fs_cleanup();
 856  err:
 857         return res;
 858 }
 859
 860 static void __exit fuse_exit(void)
 861 {
 862         printk(KERN_DEBUG "fuse exit\n");
 863
 864         fuse_ctl_cleanup();
 865         fuse_sysfs_cleanup();
 866         fuse_fs_cleanup();
 867         fuse_dev_cleanup();
 868 }
 869
 870 module_init(fuse_init);
 871 module_exit(fuse_exit);