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 fi->writectr = 0; 63 INIT_LIST_HEAD(&fi->write_files); 64 INIT_LIST_HEAD(&fi->queued_writes); 65 INIT_LIST_HEAD(&fi->writepages); 66 init_waitqueue_head(&fi->page_waitq); 67 fi->forget_req = fuse_request_alloc(); 68 if (!fi->forget_req) { 69 kmem_cache_free(fuse_inode_cachep, inode); 70 return NULL; 71 } 72 73 return inode; 74 } 75 76 static void fuse_destroy_inode(struct inode *inode) 77 { 78 struct fuse_inode *fi = get_fuse_inode(inode); 79 BUG_ON(!list_empty(&fi->write_files)); 80 BUG_ON(!list_empty(&fi->queued_writes)); 81 if (fi->forget_req) 82 fuse_request_free(fi->forget_req); 83 kmem_cache_free(fuse_inode_cachep, inode); 84 } 85 86 void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req, 87 u64 nodeid, u64 nlookup) 88 { 89 struct fuse_forget_in *inarg = &req->misc.forget_in; 90 inarg->nlookup = nlookup; 91 req->in.h.opcode = FUSE_FORGET; 92 req->in.h.nodeid = nodeid; 93 req->in.numargs = 1; 94 req->in.args[0].size = sizeof(struct fuse_forget_in); 95 req->in.args[0].value = inarg; 96 request_send_noreply(fc, req); 97 } 98 99 static void fuse_clear_inode(struct inode *inode) 100 { 101 if (inode->i_sb->s_flags & MS_ACTIVE) { 102 struct fuse_conn *fc = get_fuse_conn(inode); 103 struct fuse_inode *fi = get_fuse_inode(inode); 104 fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup); 105 fi->forget_req = NULL; 106 } 107 } 108 109 static int fuse_remount_fs(struct super_block *sb, int *flags, char *data) 110 { 111 if (*flags & MS_MANDLOCK) 112 return -EINVAL; 113 114 return 0; 115 } 116 117 void fuse_truncate(struct address_space *mapping, loff_t offset) 118 { 119 /* See vmtruncate() */ 120 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); 121 truncate_inode_pages(mapping, offset); 122 unmap_mapping_range(mapping, offset + PAGE_SIZE - 1, 0, 1); 123 } 124 125 void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr, 126 u64 attr_valid) 127 { 128 struct fuse_conn *fc = get_fuse_conn(inode); 129 struct fuse_inode *fi = get_fuse_inode(inode); 130 131 fi->attr_version = ++fc->attr_version; 132 fi->i_time = attr_valid; 133 134 inode->i_ino = attr->ino; 135 inode->i_mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777); 136 inode->i_nlink = attr->nlink; 137 inode->i_uid = attr->uid; 138 inode->i_gid = attr->gid; 139 inode->i_blocks = attr->blocks; 140 inode->i_atime.tv_sec = attr->atime; 141 inode->i_atime.tv_nsec = attr->atimensec; 142 inode->i_mtime.tv_sec = attr->mtime; 143 inode->i_mtime.tv_nsec = attr->mtimensec; 144 inode->i_ctime.tv_sec = attr->ctime; 145 inode->i_ctime.tv_nsec = attr->ctimensec; 146 147 if (attr->blksize != 0) 148 inode->i_blkbits = ilog2(attr->blksize); 149 else 150 inode->i_blkbits = inode->i_sb->s_blocksize_bits; 151 152 /* 153 * Don't set the sticky bit in i_mode, unless we want the VFS 154 * to check permissions. This prevents failures due to the 155 * check in may_delete(). 156 */ 157 fi->orig_i_mode = inode->i_mode; 158 if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS)) 159 inode->i_mode &= ~S_ISVTX; 160 } 161 162 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr, 163 u64 attr_valid, u64 attr_version) 164 { 165 struct fuse_conn *fc = get_fuse_conn(inode); 166 struct fuse_inode *fi = get_fuse_inode(inode); 167 loff_t oldsize; 168 169 spin_lock(&fc->lock); 170 if (attr_version != 0 && fi->attr_version > attr_version) { 171 spin_unlock(&fc->lock); 172 return; 173 } 174 175 fuse_change_attributes_common(inode, attr, attr_valid); 176 177 oldsize = inode->i_size; 178 i_size_write(inode, attr->size); 179 spin_unlock(&fc->lock); 180 181 if (S_ISREG(inode->i_mode) && oldsize != attr->size) { 182 if (attr->size < oldsize) 183 fuse_truncate(inode->i_mapping, attr->size); 184 invalidate_inode_pages2(inode->i_mapping); 185 } 186 } 187 188 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr) 189 { 190 inode->i_mode = attr->mode & S_IFMT; 191 inode->i_size = attr->size; 192 if (S_ISREG(inode->i_mode)) { 193 fuse_init_common(inode); 194 fuse_init_file_inode(inode); 195 } else if (S_ISDIR(inode->i_mode)) 196 fuse_init_dir(inode); 197 else if (S_ISLNK(inode->i_mode)) 198 fuse_init_symlink(inode); 199 else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || 200 S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { 201 fuse_init_common(inode); 202 init_special_inode(inode, inode->i_mode, 203 new_decode_dev(attr->rdev)); 204 } else 205 BUG(); 206 } 207 208 static int fuse_inode_eq(struct inode *inode, void *_nodeidp) 209 { 210 u64 nodeid = *(u64 *) _nodeidp; 211 if (get_node_id(inode) == nodeid) 212 return 1; 213 else 214 return 0; 215 } 216 217 static int fuse_inode_set(struct inode *inode, void *_nodeidp) 218 { 219 u64 nodeid = *(u64 *) _nodeidp; 220 get_fuse_inode(inode)->nodeid = nodeid; 221 return 0; 222 } 223 224 struct inode *fuse_iget(struct super_block *sb, u64 nodeid, 225 int generation, struct fuse_attr *attr, 226 u64 attr_valid, u64 attr_version) 227 { 228 struct inode *inode; 229 struct fuse_inode *fi; 230 struct fuse_conn *fc = get_fuse_conn_super(sb); 231 232 retry: 233 inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid); 234 if (!inode) 235 return NULL; 236 237 if ((inode->i_state & I_NEW)) { 238 inode->i_flags |= S_NOATIME|S_NOCMTIME; 239 inode->i_generation = generation; 240 inode->i_data.backing_dev_info = &fc->bdi; 241 fuse_init_inode(inode, attr); 242 unlock_new_inode(inode); 243 } else if ((inode->i_mode ^ attr->mode) & S_IFMT) { 244 /* Inode has changed type, any I/O on the old should fail */ 245 make_bad_inode(inode); 246 iput(inode); 247 goto retry; 248 } 249 250 fi = get_fuse_inode(inode); 251 spin_lock(&fc->lock); 252 fi->nlookup ++; 253 spin_unlock(&fc->lock); 254 fuse_change_attributes(inode, attr, attr_valid, attr_version); 255 256 return inode; 257 } 258 259 static void fuse_umount_begin(struct super_block *sb) 260 { 261 fuse_abort_conn(get_fuse_conn_super(sb)); 262 } 263 264 static void fuse_send_destroy(struct fuse_conn *fc) 265 { 266 struct fuse_req *req = fc->destroy_req; 267 if (req && fc->conn_init) { 268 fc->destroy_req = NULL; 269 req->in.h.opcode = FUSE_DESTROY; 270 req->force = 1; 271 request_send(fc, req); 272 fuse_put_request(fc, req); 273 } 274 } 275 276 static void fuse_put_super(struct super_block *sb) 277 { 278 struct fuse_conn *fc = get_fuse_conn_super(sb); 279 280 fuse_send_destroy(fc); 281 spin_lock(&fc->lock); 282 fc->connected = 0; 283 fc->blocked = 0; 284 spin_unlock(&fc->lock); 285 /* Flush all readers on this fs */ 286 kill_fasync(&fc->fasync, SIGIO, POLL_IN); 287 wake_up_all(&fc->waitq); 288 wake_up_all(&fc->blocked_waitq); 289 wake_up_all(&fc->reserved_req_waitq); 290 mutex_lock(&fuse_mutex); 291 list_del(&fc->entry); 292 fuse_ctl_remove_conn(fc); 293 mutex_unlock(&fuse_mutex); 294 fuse_conn_put(fc); 295 } 296 297 static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr) 298 { 299 stbuf->f_type = FUSE_SUPER_MAGIC; 300 stbuf->f_bsize = attr->bsize; 301 stbuf->f_frsize = attr->frsize; 302 stbuf->f_blocks = attr->blocks; 303 stbuf->f_bfree = attr->bfree; 304 stbuf->f_bavail = attr->bavail; 305 stbuf->f_files = attr->files; 306 stbuf->f_ffree = attr->ffree; 307 stbuf->f_namelen = attr->namelen; 308 /* fsid is left zero */ 309 } 310 311 static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf) 312 { 313 struct super_block *sb = dentry->d_sb; 314 struct fuse_conn *fc = get_fuse_conn_super(sb); 315 struct fuse_req *req; 316 struct fuse_statfs_out outarg; 317 int err; 318 319 if (!fuse_allow_task(fc, current)) { 320 buf->f_type = FUSE_SUPER_MAGIC; 321 return 0; 322 } 323 324 req = fuse_get_req(fc); 325 if (IS_ERR(req)) 326 return PTR_ERR(req); 327 328 memset(&outarg, 0, sizeof(outarg)); 329 req->in.numargs = 0; 330 req->in.h.opcode = FUSE_STATFS; 331 req->in.h.nodeid = get_node_id(dentry->d_inode); 332 req->out.numargs = 1; 333 req->out.args[0].size = 334 fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg); 335 req->out.args[0].value = &outarg; 336 request_send(fc, req); 337 err = req->out.h.error; 338 if (!err) 339 convert_fuse_statfs(buf, &outarg.st); 340 fuse_put_request(fc, req); 341 return err; 342 } 343 344 enum { 345 OPT_FD, 346 OPT_ROOTMODE, 347 OPT_USER_ID, 348 OPT_GROUP_ID, 349 OPT_DEFAULT_PERMISSIONS, 350 OPT_ALLOW_OTHER, 351 OPT_MAX_READ, 352 OPT_BLKSIZE, 353 OPT_ERR 354 }; 355 356 static match_table_t tokens = { 357 {OPT_FD, "fd=%u"}, 358 {OPT_ROOTMODE, "rootmode=%o"}, 359 {OPT_USER_ID, "user_id=%u"}, 360 {OPT_GROUP_ID, "group_id=%u"}, 361 {OPT_DEFAULT_PERMISSIONS, "default_permissions"}, 362 {OPT_ALLOW_OTHER, "allow_other"}, 363 {OPT_MAX_READ, "max_read=%u"}, 364 {OPT_BLKSIZE, "blksize=%u"}, 365 {OPT_ERR, NULL} 366 }; 367 368 static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev) 369 { 370 char *p; 371 memset(d, 0, sizeof(struct fuse_mount_data)); 372 d->max_read = ~0; 373 d->blksize = FUSE_DEFAULT_BLKSIZE; 374 375 while ((p = strsep(&opt, ",")) != NULL) { 376 int token; 377 int value; 378 substring_t args[MAX_OPT_ARGS]; 379 if (!*p) 380 continue; 381 382 token = match_token(p, tokens, args); 383 switch (token) { 384 case OPT_FD: 385 if (match_int(&args[0], &value)) 386 return 0; 387 d->fd = value; 388 d->fd_present = 1; 389 break; 390 391 case OPT_ROOTMODE: 392 if (match_octal(&args[0], &value)) 393 return 0; 394 if (!fuse_valid_type(value)) 395 return 0; 396 d->rootmode = value; 397 d->rootmode_present = 1; 398 break; 399 400 case OPT_USER_ID: 401 if (match_int(&args[0], &value)) 402 return 0; 403 d->user_id = value; 404 d->user_id_present = 1; 405 break; 406 407 case OPT_GROUP_ID: 408 if (match_int(&args[0], &value)) 409 return 0; 410 d->group_id = value; 411 d->group_id_present = 1; 412 break; 413 414 case OPT_DEFAULT_PERMISSIONS: 415 d->flags |= FUSE_DEFAULT_PERMISSIONS; 416 break; 417 418 case OPT_ALLOW_OTHER: 419 d->flags |= FUSE_ALLOW_OTHER; 420 break; 421 422 case OPT_MAX_READ: 423 if (match_int(&args[0], &value)) 424 return 0; 425 d->max_read = value; 426 break; 427 428 case OPT_BLKSIZE: 429 if (!is_bdev || match_int(&args[0], &value)) 430 return 0; 431 d->blksize = value; 432 break; 433 434 default: 435 return 0; 436 } 437 } 438 439 if (!d->fd_present || !d->rootmode_present || 440 !d->user_id_present || !d->group_id_present) 441 return 0; 442 443 return 1; 444 } 445 446 static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt) 447 { 448 struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb); 449 450 seq_printf(m, ",user_id=%u", fc->user_id); 451 seq_printf(m, ",group_id=%u", fc->group_id); 452 if (fc->flags & FUSE_DEFAULT_PERMISSIONS) 453 seq_puts(m, ",default_permissions"); 454 if (fc->flags & FUSE_ALLOW_OTHER) 455 seq_puts(m, ",allow_other"); 456 if (fc->max_read != ~0) 457 seq_printf(m, ",max_read=%u", fc->max_read); 458 if (mnt->mnt_sb->s_bdev && 459 mnt->mnt_sb->s_blocksize != FUSE_DEFAULT_BLKSIZE) 460 seq_printf(m, ",blksize=%lu", mnt->mnt_sb->s_blocksize); 461 return 0; 462 } 463 464 static struct fuse_conn *new_conn(struct super_block *sb) 465 { 466 struct fuse_conn *fc; 467 int err; 468 469 fc = kzalloc(sizeof(*fc), GFP_KERNEL); 470 if (fc) { 471 spin_lock_init(&fc->lock); 472 mutex_init(&fc->inst_mutex); 473 atomic_set(&fc->count, 1); 474 init_waitqueue_head(&fc->waitq); 475 init_waitqueue_head(&fc->blocked_waitq); 476 init_waitqueue_head(&fc->reserved_req_waitq); 477 INIT_LIST_HEAD(&fc->pending); 478 INIT_LIST_HEAD(&fc->processing); 479 INIT_LIST_HEAD(&fc->io); 480 INIT_LIST_HEAD(&fc->interrupts); 481 INIT_LIST_HEAD(&fc->bg_queue); 482 atomic_set(&fc->num_waiting, 0); 483 fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE; 484 fc->bdi.unplug_io_fn = default_unplug_io_fn; 485 /* fuse does it's own writeback accounting */ 486 fc->bdi.capabilities = BDI_CAP_NO_ACCT_WB; 487 fc->dev = sb->s_dev; 488 err = bdi_init(&fc->bdi); 489 if (err) 490 goto error_kfree; 491 err = bdi_register_dev(&fc->bdi, fc->dev); 492 if (err) 493 goto error_bdi_destroy; 494 /* 495 * For a single fuse filesystem use max 1% of dirty + 496 * writeback threshold. 497 * 498 * This gives about 1M of write buffer for memory maps on a 499 * machine with 1G and 10% dirty_ratio, which should be more 500 * than enough. 501 * 502 * Privileged users can raise it by writing to 503 * 504 * /sys/class/bdi/<bdi>/max_ratio 505 */ 506 bdi_set_max_ratio(&fc->bdi, 1); 507 fc->reqctr = 0; 508 fc->blocked = 1; 509 fc->attr_version = 1; 510 get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key)); 511 } 512 return fc; 513 514 error_bdi_destroy: 515 bdi_destroy(&fc->bdi); 516 error_kfree: 517 mutex_destroy(&fc->inst_mutex); 518 kfree(fc); 519 return NULL; 520 } 521 522 void fuse_conn_put(struct fuse_conn *fc) 523 { 524 if (atomic_dec_and_test(&fc->count)) { 525 if (fc->destroy_req) 526 fuse_request_free(fc->destroy_req); 527 mutex_destroy(&fc->inst_mutex); 528 bdi_destroy(&fc->bdi); 529 kfree(fc); 530 } 531 } 532 533 struct fuse_conn *fuse_conn_get(struct fuse_conn *fc) 534 { 535 atomic_inc(&fc->count); 536 return fc; 537 } 538 539 static struct inode *get_root_inode(struct super_block *sb, unsigned mode) 540 { 541 struct fuse_attr attr; 542 memset(&attr, 0, sizeof(attr)); 543 544 attr.mode = mode; 545 attr.ino = FUSE_ROOT_ID; 546 attr.nlink = 1; 547 return fuse_iget(sb, 1, 0, &attr, 0, 0); 548 } 549 550 static const struct super_operations fuse_super_operations = { 551 .alloc_inode = fuse_alloc_inode, 552 .destroy_inode = fuse_destroy_inode, 553 .clear_inode = fuse_clear_inode, 554 .drop_inode = generic_delete_inode, 555 .remount_fs = fuse_remount_fs, 556 .put_super = fuse_put_super, 557 .umount_begin = fuse_umount_begin, 558 .statfs = fuse_statfs, 559 .show_options = fuse_show_options, 560 }; 561 562 static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) 563 { 564 struct fuse_init_out *arg = &req->misc.init_out; 565 566 if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION) 567 fc->conn_error = 1; 568 else { 569 unsigned long ra_pages; 570 571 if (arg->minor >= 6) { 572 ra_pages = arg->max_readahead / PAGE_CACHE_SIZE; 573 if (arg->flags & FUSE_ASYNC_READ) 574 fc->async_read = 1; 575 if (!(arg->flags & FUSE_POSIX_LOCKS)) 576 fc->no_lock = 1; 577 if (arg->flags & FUSE_ATOMIC_O_TRUNC) 578 fc->atomic_o_trunc = 1; 579 if (arg->flags & FUSE_BIG_WRITES) 580 fc->big_writes = 1; 581 } else { 582 ra_pages = fc->max_read / PAGE_CACHE_SIZE; 583 fc->no_lock = 1; 584 } 585 586 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages); 587 fc->minor = arg->minor; 588 fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; 589 fc->max_write = min_t(unsigned, 4096, fc->max_write); 590 fc->conn_init = 1; 591 } 592 fuse_put_request(fc, req); 593 fc->blocked = 0; 594 wake_up_all(&fc->blocked_waitq); 595 } 596 597 static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) 598 { 599 struct fuse_init_in *arg = &req->misc.init_in; 600 601 arg->major = FUSE_KERNEL_VERSION; 602 arg->minor = FUSE_KERNEL_MINOR_VERSION; 603 arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE; 604 arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | 605 FUSE_BIG_WRITES; 606 req->in.h.opcode = FUSE_INIT; 607 req->in.numargs = 1; 608 req->in.args[0].size = sizeof(*arg); 609 req->in.args[0].value = arg; 610 req->out.numargs = 1; 611 /* Variable length arguement used for backward compatibility 612 with interface version < 7.5. Rest of init_out is zeroed 613 by do_get_request(), so a short reply is not a problem */ 614 req->out.argvar = 1; 615 req->out.args[0].size = sizeof(struct fuse_init_out); 616 req->out.args[0].value = &req->misc.init_out; 617 req->end = process_init_reply; 618 request_send_background(fc, req); 619 } 620 621 static int fuse_fill_super(struct super_block *sb, void *data, int silent) 622 { 623 struct fuse_conn *fc; 624 struct inode *root; 625 struct fuse_mount_data d; 626 struct file *file; 627 struct dentry *root_dentry; 628 struct fuse_req *init_req; 629 int err; 630 int is_bdev = sb->s_bdev != NULL; 631 632 if (sb->s_flags & MS_MANDLOCK) 633 return -EINVAL; 634 635 if (!parse_fuse_opt((char *) data, &d, is_bdev)) 636 return -EINVAL; 637 638 if (is_bdev) { 639 #ifdef CONFIG_BLOCK 640 if (!sb_set_blocksize(sb, d.blksize)) 641 return -EINVAL; 642 #endif 643 } else { 644 sb->s_blocksize = PAGE_CACHE_SIZE; 645 sb->s_blocksize_bits = PAGE_CACHE_SHIFT; 646 } 647 sb->s_magic = FUSE_SUPER_MAGIC; 648 sb->s_op = &fuse_super_operations; 649 sb->s_maxbytes = MAX_LFS_FILESIZE; 650 651 file = fget(d.fd); 652 if (!file) 653 return -EINVAL; 654 655 if (file->f_op != &fuse_dev_operations) 656 return -EINVAL; 657 658 fc = new_conn(sb); 659 if (!fc) 660 return -ENOMEM; 661 662 fc->flags = d.flags; 663 fc->user_id = d.user_id; 664 fc->group_id = d.group_id; 665 fc->max_read = min_t(unsigned, 4096, d.max_read); 666 667 /* Used by get_root_inode() */ 668 sb->s_fs_info = fc; 669 670 err = -ENOMEM; 671 root = get_root_inode(sb, d.rootmode); 672 if (!root) 673 goto err; 674 675 root_dentry = d_alloc_root(root); 676 if (!root_dentry) { 677 iput(root); 678 goto err; 679 } 680 681 init_req = fuse_request_alloc(); 682 if (!init_req) 683 goto err_put_root; 684 685 if (is_bdev) { 686 fc->destroy_req = fuse_request_alloc(); 687 if (!fc->destroy_req) 688 goto err_put_root; 689 } 690 691 mutex_lock(&fuse_mutex); 692 err = -EINVAL; 693 if (file->private_data) 694 goto err_unlock; 695 696 err = fuse_ctl_add_conn(fc); 697 if (err) 698 goto err_unlock; 699 700 list_add_tail(&fc->entry, &fuse_conn_list); 701 sb->s_root = root_dentry; 702 fc->connected = 1; 703 file->private_data = fuse_conn_get(fc); 704 mutex_unlock(&fuse_mutex); 705 /* 706 * atomic_dec_and_test() in fput() provides the necessary 707 * memory barrier for file->private_data to be visible on all 708 * CPUs after this 709 */ 710 fput(file); 711 712 fuse_send_init(fc, init_req); 713 714 return 0; 715 716 err_unlock: 717 mutex_unlock(&fuse_mutex); 718 fuse_request_free(init_req); 719 err_put_root: 720 dput(root_dentry); 721 err: 722 fput(file); 723 fuse_conn_put(fc); 724 return err; 725 } 726 727 static int fuse_get_sb(struct file_system_type *fs_type, 728 int flags, const char *dev_name, 729 void *raw_data, struct vfsmount *mnt) 730 { 731 return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt); 732 } 733 734 static struct file_system_type fuse_fs_type = { 735 .owner = THIS_MODULE, 736 .name = "fuse", 737 .fs_flags = FS_HAS_SUBTYPE, 738 .get_sb = fuse_get_sb, 739 .kill_sb = kill_anon_super, 740 }; 741 742 #ifdef CONFIG_BLOCK 743 static int fuse_get_sb_blk(struct file_system_type *fs_type, 744 int flags, const char *dev_name, 745 void *raw_data, struct vfsmount *mnt) 746 { 747 return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super, 748 mnt); 749 } 750 751 static struct file_system_type fuseblk_fs_type = { 752 .owner = THIS_MODULE, 753 .name = "fuseblk", 754 .get_sb = fuse_get_sb_blk, 755 .kill_sb = kill_block_super, 756 .fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE, 757 }; 758 759 static inline int register_fuseblk(void) 760 { 761 return register_filesystem(&fuseblk_fs_type); 762 } 763 764 static inline void unregister_fuseblk(void) 765 { 766 unregister_filesystem(&fuseblk_fs_type); 767 } 768 #else 769 static inline int register_fuseblk(void) 770 { 771 return 0; 772 } 773 774 static inline void unregister_fuseblk(void) 775 { 776 } 777 #endif 778 779 static void fuse_inode_init_once(struct kmem_cache *cachep, void *foo) 780 { 781 struct inode * inode = foo; 782 783 inode_init_once(inode); 784 } 785 786 static int __init fuse_fs_init(void) 787 { 788 int err; 789 790 err = register_filesystem(&fuse_fs_type); 791 if (err) 792 goto out; 793 794 err = register_fuseblk(); 795 if (err) 796 goto out_unreg; 797 798 fuse_inode_cachep = kmem_cache_create("fuse_inode", 799 sizeof(struct fuse_inode), 800 0, SLAB_HWCACHE_ALIGN, 801 fuse_inode_init_once); 802 err = -ENOMEM; 803 if (!fuse_inode_cachep) 804 goto out_unreg2; 805 806 return 0; 807 808 out_unreg2: 809 unregister_fuseblk(); 810 out_unreg: 811 unregister_filesystem(&fuse_fs_type); 812 out: 813 return err; 814 } 815 816 static void fuse_fs_cleanup(void) 817 { 818 unregister_filesystem(&fuse_fs_type); 819 unregister_fuseblk(); 820 kmem_cache_destroy(fuse_inode_cachep); 821 } 822 823 static struct kobject *fuse_kobj; 824 static struct kobject *connections_kobj; 825 826 static int fuse_sysfs_init(void) 827 { 828 int err; 829 830 fuse_kobj = kobject_create_and_add("fuse", fs_kobj); 831 if (!fuse_kobj) { 832 err = -ENOMEM; 833 goto out_err; 834 } 835 836 connections_kobj = kobject_create_and_add("connections", fuse_kobj); 837 if (!connections_kobj) { 838 err = -ENOMEM; 839 goto out_fuse_unregister; 840 } 841 842 return 0; 843 844 out_fuse_unregister: 845 kobject_put(fuse_kobj); 846 out_err: 847 return err; 848 } 849 850 static void fuse_sysfs_cleanup(void) 851 { 852 kobject_put(connections_kobj); 853 kobject_put(fuse_kobj); 854 } 855 856 static int __init fuse_init(void) 857 { 858 int res; 859 860 printk("fuse init (API version %i.%i)\n", 861 FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION); 862 863 INIT_LIST_HEAD(&fuse_conn_list); 864 res = fuse_fs_init(); 865 if (res) 866 goto err; 867 868 res = fuse_dev_init(); 869 if (res) 870 goto err_fs_cleanup; 871 872 res = fuse_sysfs_init(); 873 if (res) 874 goto err_dev_cleanup; 875 876 res = fuse_ctl_init(); 877 if (res) 878 goto err_sysfs_cleanup; 879 880 return 0; 881 882 err_sysfs_cleanup: 883 fuse_sysfs_cleanup(); 884 err_dev_cleanup: 885 fuse_dev_cleanup(); 886 err_fs_cleanup: 887 fuse_fs_cleanup(); 888 err: 889 return res; 890 } 891 892 static void __exit fuse_exit(void) 893 { 894 printk(KERN_DEBUG "fuse exit\n"); 895 896 fuse_ctl_cleanup(); 897 fuse_sysfs_cleanup(); 898 fuse_fs_cleanup(); 899 fuse_dev_cleanup(); 900 } 901 902 module_init(fuse_init); 903 module_exit(fuse_exit); 904