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 super_block *sb)
 246 {
 247         fuse_abort_conn(get_fuse_conn_super(sb));
 248 }
 249
 250 static void fuse_send_destroy(struct fuse_conn *fc)
 251 {
 252         struct fuse_req *req = fc->destroy_req;
 253         if (req && fc->conn_init) {
 254                 fc->destroy_req = NULL;
 255                 req->in.h.opcode = FUSE_DESTROY;
 256                 req->force = 1;
 257                 request_send(fc, req);
 258                 fuse_put_request(fc, req);
 259         }
 260 }
 261
 262 static void fuse_put_super(struct super_block *sb)
 263 {
 264         struct fuse_conn *fc = get_fuse_conn_super(sb);
 265
 266         fuse_send_destroy(fc);
 267         spin_lock(&fc->lock);
 268         fc->connected = 0;
 269         fc->blocked = 0;
 270         spin_unlock(&fc->lock);
 271         /* Flush all readers on this fs */
 272         kill_fasync(&fc->fasync, SIGIO, POLL_IN);
 273         wake_up_all(&fc->waitq);
 274         wake_up_all(&fc->blocked_waitq);
 275         wake_up_all(&fc->reserved_req_waitq);
 276         mutex_lock(&fuse_mutex);
 277         list_del(&fc->entry);
 278         fuse_ctl_remove_conn(fc);
 279         mutex_unlock(&fuse_mutex);
 280         fuse_conn_put(fc);
 281 }
 282
 283 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
 284 {
 285         stbuf->f_type    = FUSE_SUPER_MAGIC;
 286         stbuf->f_bsize   = attr->bsize;
 287         stbuf->f_frsize  = attr->frsize;
 288         stbuf->f_blocks  = attr->blocks;
 289         stbuf->f_bfree   = attr->bfree;
 290         stbuf->f_bavail  = attr->bavail;
 291         stbuf->f_files   = attr->files;
 292         stbuf->f_ffree   = attr->ffree;
 293         stbuf->f_namelen = attr->namelen;
 294         /* fsid is left zero */
 295 }
 296
 297 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
 298 {
 299         struct super_block *sb = dentry->d_sb;
 300         struct fuse_conn *fc = get_fuse_conn_super(sb);
 301         struct fuse_req *req;
 302         struct fuse_statfs_out outarg;
 303         int err;
 304
 305         if (!fuse_allow_task(fc, current)) {
 306                 buf->f_type = FUSE_SUPER_MAGIC;
 307                 return 0;
 308         }
 309
 310         req = fuse_get_req(fc);
 311         if (IS_ERR(req))
 312                 return PTR_ERR(req);
 313
 314         memset(&outarg, 0, sizeof(outarg));
 315         req->in.numargs = 0;
 316         req->in.h.opcode = FUSE_STATFS;
 317         req->in.h.nodeid = get_node_id(dentry->d_inode);
 318         req->out.numargs = 1;
 319         req->out.args[0].size =
 320                 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
 321         req->out.args[0].value = &outarg;
 322         request_send(fc, req);
 323         err = req->out.h.error;
 324         if (!err)
 325                 convert_fuse_statfs(buf, &outarg.st);
 326         fuse_put_request(fc, req);
 327         return err;
 328 }
 329
 330 enum {
 331         OPT_FD,
 332         OPT_ROOTMODE,
 333         OPT_USER_ID,
 334         OPT_GROUP_ID,
 335         OPT_DEFAULT_PERMISSIONS,
 336         OPT_ALLOW_OTHER,
 337         OPT_MAX_READ,
 338         OPT_BLKSIZE,
 339         OPT_ERR
 340 };
 341
 342 static match_table_t tokens = {
 343         {OPT_FD,                        "fd=%u"},
 344         {OPT_ROOTMODE,                  "rootmode=%o"},
 345         {OPT_USER_ID,                   "user_id=%u"},
 346         {OPT_GROUP_ID,                  "group_id=%u"},
 347         {OPT_DEFAULT_PERMISSIONS,       "default_permissions"},
 348         {OPT_ALLOW_OTHER,               "allow_other"},
 349         {OPT_MAX_READ,                  "max_read=%u"},
 350         {OPT_BLKSIZE,                   "blksize=%u"},
 351         {OPT_ERR,                       NULL}
 352 };
 353
 354 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 355 {
 356         char *p;
 357         memset(d, 0, sizeof(struct fuse_mount_data));
 358         d->max_read = ~0;
 359         d->blksize = FUSE_DEFAULT_BLKSIZE;
 360
 361         while ((p = strsep(&opt, ",")) != NULL) {
 362                 int token;
 363                 int value;
 364                 substring_t args[MAX_OPT_ARGS];
 365                 if (!*p)
 366                         continue;
 367
 368                 token = match_token(p, tokens, args);
 369                 switch (token) {
 370                 case OPT_FD:
 371                         if (match_int(&args[0], &value))
 372                                 return 0;
 373                         d->fd = value;
 374                         d->fd_present = 1;
 375                         break;
 376
 377                 case OPT_ROOTMODE:
 378                         if (match_octal(&args[0], &value))
 379                                 return 0;
 380                         if (!fuse_valid_type(value))
 381                                 return 0;
 382                         d->rootmode = value;
 383                         d->rootmode_present = 1;
 384                         break;
 385
 386                 case OPT_USER_ID:
 387                         if (match_int(&args[0], &value))
 388                                 return 0;
 389                         d->user_id = value;
 390                         d->user_id_present = 1;
 391                         break;
 392
 393                 case OPT_GROUP_ID:
 394                         if (match_int(&args[0], &value))
 395                                 return 0;
 396                         d->group_id = value;
 397                         d->group_id_present = 1;
 398                         break;
 399
 400                 case OPT_DEFAULT_PERMISSIONS:
 401                         d->flags |= FUSE_DEFAULT_PERMISSIONS;
 402                         break;
 403
 404                 case OPT_ALLOW_OTHER:
 405                         d->flags |= FUSE_ALLOW_OTHER;
 406                         break;
 407
 408                 case OPT_MAX_READ:
 409                         if (match_int(&args[0], &value))
 410                                 return 0;
 411                         d->max_read = value;
 412                         break;
 413
 414                 case OPT_BLKSIZE:
 415                         if (!is_bdev || match_int(&args[0], &value))
 416                                 return 0;
 417                         d->blksize = value;
 418                         break;
 419
 420                 default:
 421                         return 0;
 422                 }
 423         }
 424
 425         if (!d->fd_present || !d->rootmode_present ||
 426             !d->user_id_present || !d->group_id_present)
 427                 return 0;
 428
 429         return 1;
 430 }
 431
 432 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
 433 {
 434         struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
 435
 436         seq_printf(m, ",user_id=%u", fc->user_id);
 437         seq_printf(m, ",group_id=%u", fc->group_id);
 438         if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 439                 seq_puts(m, ",default_permissions");
 440         if (fc->flags & FUSE_ALLOW_OTHER)
 441                 seq_puts(m, ",allow_other");
 442         if (fc->max_read != ~0)
 443                 seq_printf(m, ",max_read=%u", fc->max_read);
 444         if (mnt->mnt_sb->s_bdev &&
 445             mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE)
 446                 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize);
 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                 INIT_LIST_HEAD(&fc->bg_queue);
 468                 atomic_set(&fc->num_waiting, 0);
 469                 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
 470                 fc->bdi.unplug_io_fn = default_unplug_io_fn;
 471                 err = bdi_init(&fc->bdi);
 472                 if (err) {
 473                         kfree(fc);
 474                         fc = NULL;
 475                         goto out;
 476                 }
 477                 fc->reqctr = 0;
 478                 fc->blocked = 1;
 479                 fc->attr_version = 1;
 480                 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 481         }
 482 out:
 483         return fc;
 484 }
 485
 486 void fuse_conn_put(struct fuse_conn *fc)
 487 {
 488         if (atomic_dec_and_test(&fc->count)) {
 489                 if (fc->destroy_req)
 490                         fuse_request_free(fc->destroy_req);
 491                 mutex_destroy(&fc->inst_mutex);
 492                 bdi_destroy(&fc->bdi);
 493                 kfree(fc);
 494         }
 495 }
 496
 497 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
 498 {
 499         atomic_inc(&fc->count);
 500         return fc;
 501 }
 502
 503 static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
 504 {
 505         struct fuse_attr attr;
 506         memset(&attr, 0, sizeof(attr));
 507
 508         attr.mode = mode;
 509         attr.ino = FUSE_ROOT_ID;
 510         attr.nlink = 1;
 511         return fuse_iget(sb, 1, 0, &attr, 0, 0);
 512 }
 513
 514 static const struct super_operations fuse_super_operations = {
 515         .alloc_inode    = fuse_alloc_inode,
 516         .destroy_inode  = fuse_destroy_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_ATOMIC_O_TRUNC;
 566         req->in.h.opcode = FUSE_INIT;
 567         req->in.numargs = 1;
 568         req->in.args[0].size = sizeof(*arg);
 569         req->in.args[0].value = arg;
 570         req->out.numargs = 1;
 571         /* Variable length arguement used for backward compatibility
 572            with interface version < 7.5.  Rest of init_out is zeroed
 573            by do_get_request(), so a short reply is not a problem */
 574         req->out.argvar = 1;
 575         req->out.args[0].size = sizeof(struct fuse_init_out);
 576         req->out.args[0].value = &req->misc.init_out;
 577         req->end = process_init_reply;
 578         request_send_background(fc, req);
 579 }
 580
 581 static u64 conn_id(void)
 582 {
 583         static u64 ctr = 1;
 584         return ctr++;
 585 }
 586
 587 static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 588 {
 589         struct fuse_conn *fc;
 590         struct inode *root;
 591         struct fuse_mount_data d;
 592         struct file *file;
 593         struct dentry *root_dentry;
 594         struct fuse_req *init_req;
 595         int err;
 596         int is_bdev = sb->s_bdev != NULL;
 597
 598         if (sb->s_flags & MS_MANDLOCK)
 599                 return -EINVAL;
 600
 601         if (!parse_fuse_opt((char *) data, &d, is_bdev))
 602                 return -EINVAL;
 603
 604         if (is_bdev) {
 605 #ifdef CONFIG_BLOCK
 606                 if (!sb_set_blocksize(sb, d.blksize))
 607                         return -EINVAL;
 608 #endif
 609         } else {
 610                 sb->s_blocksize = PAGE_CACHE_SIZE;
 611                 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
 612         }
 613         sb->s_magic = FUSE_SUPER_MAGIC;
 614         sb->s_op = &fuse_super_operations;
 615         sb->s_maxbytes = MAX_LFS_FILESIZE;
 616
 617         file = fget(d.fd);
 618         if (!file)
 619                 return -EINVAL;
 620
 621         if (file->f_op != &fuse_dev_operations)
 622                 return -EINVAL;
 623
 624         fc = new_conn();
 625         if (!fc)
 626                 return -ENOMEM;
 627
 628         fc->flags = d.flags;
 629         fc->user_id = d.user_id;
 630         fc->group_id = d.group_id;
 631         fc->max_read = d.max_read;
 632
 633         /* Used by get_root_inode() */
 634         sb->s_fs_info = fc;
 635
 636         err = -ENOMEM;
 637         root = get_root_inode(sb, d.rootmode);
 638         if (!root)
 639                 goto err;
 640
 641         root_dentry = d_alloc_root(root);
 642         if (!root_dentry) {
 643                 iput(root);
 644                 goto err;
 645         }
 646
 647         init_req = fuse_request_alloc();
 648         if (!init_req)
 649                 goto err_put_root;
 650
 651         if (is_bdev) {
 652                 fc->destroy_req = fuse_request_alloc();
 653                 if (!fc->destroy_req)
 654                         goto err_put_root;
 655         }
 656
 657         mutex_lock(&fuse_mutex);
 658         err = -EINVAL;
 659         if (file->private_data)
 660                 goto err_unlock;
 661
 662         fc->id = conn_id();
 663         err = fuse_ctl_add_conn(fc);
 664         if (err)
 665                 goto err_unlock;
 666
 667         list_add_tail(&fc->entry, &fuse_conn_list);
 668         sb->s_root = root_dentry;
 669         fc->connected = 1;
 670         file->private_data = fuse_conn_get(fc);
 671         mutex_unlock(&fuse_mutex);
 672         /*
 673          * atomic_dec_and_test() in fput() provides the necessary
 674          * memory barrier for file->private_data to be visible on all
 675          * CPUs after this
 676          */
 677         fput(file);
 678
 679         fuse_send_init(fc, init_req);
 680
 681         return 0;
 682
 683  err_unlock:
 684         mutex_unlock(&fuse_mutex);
 685         fuse_request_free(init_req);
 686  err_put_root:
 687         dput(root_dentry);
 688  err:
 689         fput(file);
 690         fuse_conn_put(fc);
 691         return err;
 692 }
 693
 694 static int fuse_get_sb(struct file_system_type *fs_type,
 695                        int flags, const char *dev_name,
 696                        void *raw_data, struct vfsmount *mnt)
 697 {
 698         return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
 699 }
 700
 701 static struct file_system_type fuse_fs_type = {
 702         .owner          = THIS_MODULE,
 703         .name           = "fuse",
 704         .fs_flags       = FS_HAS_SUBTYPE,
 705         .get_sb         = fuse_get_sb,
 706         .kill_sb        = kill_anon_super,
 707 };
 708
 709 #ifdef CONFIG_BLOCK
 710 static int fuse_get_sb_blk(struct file_system_type *fs_type,
 711                            int flags, const char *dev_name,
 712                            void *raw_data, struct vfsmount *mnt)
 713 {
 714         return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
 715                            mnt);
 716 }
 717
 718 static struct file_system_type fuseblk_fs_type = {
 719         .owner          = THIS_MODULE,
 720         .name           = "fuseblk",
 721         .get_sb         = fuse_get_sb_blk,
 722         .kill_sb        = kill_block_super,
 723         .fs_flags       = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
 724 };
 725
 726 static inline int register_fuseblk(void)
 727 {
 728         return register_filesystem(&fuseblk_fs_type);
 729 }
 730
 731 static inline void unregister_fuseblk(void)
 732 {
 733         unregister_filesystem(&fuseblk_fs_type);
 734 }
 735 #else
 736 static inline int register_fuseblk(void)
 737 {
 738         return 0;
 739 }
 740
 741 static inline void unregister_fuseblk(void)
 742 {
 743 }
 744 #endif
 745
 746 static void fuse_inode_init_once(struct kmem_cache *cachep, void *foo)
 747 {
 748         struct inode * inode = foo;
 749
 750         inode_init_once(inode);
 751 }
 752
 753 static int __init fuse_fs_init(void)
 754 {
 755         int err;
 756
 757         err = register_filesystem(&fuse_fs_type);
 758         if (err)
 759                 goto out;
 760
 761         err = register_fuseblk();
 762         if (err)
 763                 goto out_unreg;
 764
 765         fuse_inode_cachep = kmem_cache_create("fuse_inode",
 766                                               sizeof(struct fuse_inode),
 767                                               0, SLAB_HWCACHE_ALIGN,
 768                                               fuse_inode_init_once);
 769         err = -ENOMEM;
 770         if (!fuse_inode_cachep)
 771                 goto out_unreg2;
 772
 773         return 0;
 774
 775  out_unreg2:
 776         unregister_fuseblk();
 777  out_unreg:
 778         unregister_filesystem(&fuse_fs_type);
 779  out:
 780         return err;
 781 }
 782
 783 static void fuse_fs_cleanup(void)
 784 {
 785         unregister_filesystem(&fuse_fs_type);
 786         unregister_fuseblk();
 787         kmem_cache_destroy(fuse_inode_cachep);
 788 }
 789
 790 static struct kobject *fuse_kobj;
 791 static struct kobject *connections_kobj;
 792
 793 static int fuse_sysfs_init(void)
 794 {
 795         int err;
 796
 797         fuse_kobj = kobject_create_and_add("fuse", fs_kobj);
 798         if (!fuse_kobj) {
 799                 err = -ENOMEM;
 800                 goto out_err;
 801         }
 802
 803         connections_kobj = kobject_create_and_add("connections", fuse_kobj);
 804         if (!connections_kobj) {
 805                 err = -ENOMEM;
 806                 goto out_fuse_unregister;
 807         }
 808
 809         return 0;
 810
 811  out_fuse_unregister:
 812         kobject_put(fuse_kobj);
 813  out_err:
 814         return err;
 815 }
 816
 817 static void fuse_sysfs_cleanup(void)
 818 {
 819         kobject_put(connections_kobj);
 820         kobject_put(fuse_kobj);
 821 }
 822
 823 static int __init fuse_init(void)
 824 {
 825         int res;
 826
 827         printk("fuse init (API version %i.%i)\n",
 828                FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
 829
 830         INIT_LIST_HEAD(&fuse_conn_list);
 831         res = fuse_fs_init();
 832         if (res)
 833                 goto err;
 834
 835         res = fuse_dev_init();
 836         if (res)
 837                 goto err_fs_cleanup;
 838
 839         res = fuse_sysfs_init();
 840         if (res)
 841                 goto err_dev_cleanup;
 842
 843         res = fuse_ctl_init();
 844         if (res)
 845                 goto err_sysfs_cleanup;
 846
 847         return 0;
 848
 849  err_sysfs_cleanup:
 850         fuse_sysfs_cleanup();
 851  err_dev_cleanup:
 852         fuse_dev_cleanup();
 853  err_fs_cleanup:
 854         fuse_fs_cleanup();
 855  err:
 856         return res;
 857 }
 858
 859 static void __exit fuse_exit(void)
 860 {
 861         printk(KERN_DEBUG "fuse exit\n");
 862
 863         fuse_ctl_cleanup();
 864         fuse_sysfs_cleanup();
 865         fuse_fs_cleanup();
 866         fuse_dev_cleanup();
 867 }
 868
 869 module_init(fuse_init);
 870 module_exit(fuse_exit);