1 /* 2 * Copyright (C) 2007 Oracle. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19 #include <linux/blkdev.h> 20 #include <linux/module.h> 21 #include <linux/buffer_head.h> 22 #include <linux/fs.h> 23 #include <linux/pagemap.h> 24 #include <linux/highmem.h> 25 #include <linux/time.h> 26 #include <linux/init.h> 27 #include <linux/seq_file.h> 28 #include <linux/string.h> 29 #include <linux/backing-dev.h> 30 #include <linux/mount.h> 31 #include <linux/mpage.h> 32 #include <linux/swap.h> 33 #include <linux/writeback.h> 34 #include <linux/statfs.h> 35 #include <linux/compat.h> 36 #include <linux/parser.h> 37 #include <linux/ctype.h> 38 #include <linux/namei.h> 39 #include <linux/miscdevice.h> 40 #include <linux/magic.h> 41 #include <linux/slab.h> 42 #include "compat.h" 43 #include "ctree.h" 44 #include "disk-io.h" 45 #include "transaction.h" 46 #include "btrfs_inode.h" 47 #include "ioctl.h" 48 #include "print-tree.h" 49 #include "xattr.h" 50 #include "volumes.h" 51 #include "version.h" 52 #include "export.h" 53 #include "compression.h" 54 55 static const struct super_operations btrfs_super_ops; 56 57 static void btrfs_put_super(struct super_block *sb) 58 { 59 struct btrfs_root *root = btrfs_sb(sb); 60 int ret; 61 62 ret = close_ctree(root); 63 sb->s_fs_info = NULL; 64 } 65 66 enum { 67 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, 68 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, 69 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, 70 Opt_compress_force, Opt_notreelog, Opt_ratio, Opt_flushoncommit, 71 Opt_discard, Opt_err, 72 }; 73 74 static match_table_t tokens = { 75 {Opt_degraded, "degraded"}, 76 {Opt_subvol, "subvol=%s"}, 77 {Opt_subvolid, "subvolid=%d"}, 78 {Opt_device, "device=%s"}, 79 {Opt_nodatasum, "nodatasum"}, 80 {Opt_nodatacow, "nodatacow"}, 81 {Opt_nobarrier, "nobarrier"}, 82 {Opt_max_inline, "max_inline=%s"}, 83 {Opt_alloc_start, "alloc_start=%s"}, 84 {Opt_thread_pool, "thread_pool=%d"}, 85 {Opt_compress, "compress"}, 86 {Opt_compress_force, "compress-force"}, 87 {Opt_ssd, "ssd"}, 88 {Opt_ssd_spread, "ssd_spread"}, 89 {Opt_nossd, "nossd"}, 90 {Opt_noacl, "noacl"}, 91 {Opt_notreelog, "notreelog"}, 92 {Opt_flushoncommit, "flushoncommit"}, 93 {Opt_ratio, "metadata_ratio=%d"}, 94 {Opt_discard, "discard"}, 95 {Opt_err, NULL}, 96 }; 97 98 /* 99 * Regular mount options parser. Everything that is needed only when 100 * reading in a new superblock is parsed here. 101 */ 102 int btrfs_parse_options(struct btrfs_root *root, char *options) 103 { 104 struct btrfs_fs_info *info = root->fs_info; 105 substring_t args[MAX_OPT_ARGS]; 106 char *p, *num, *orig; 107 int intarg; 108 int ret = 0; 109 110 if (!options) 111 return 0; 112 113 /* 114 * strsep changes the string, duplicate it because parse_options 115 * gets called twice 116 */ 117 options = kstrdup(options, GFP_NOFS); 118 if (!options) 119 return -ENOMEM; 120 121 orig = options; 122 123 while ((p = strsep(&options, ",")) != NULL) { 124 int token; 125 if (!*p) 126 continue; 127 128 token = match_token(p, tokens, args); 129 switch (token) { 130 case Opt_degraded: 131 printk(KERN_INFO "btrfs: allowing degraded mounts\n"); 132 btrfs_set_opt(info->mount_opt, DEGRADED); 133 break; 134 case Opt_subvol: 135 case Opt_subvolid: 136 case Opt_device: 137 /* 138 * These are parsed by btrfs_parse_early_options 139 * and can be happily ignored here. 140 */ 141 break; 142 case Opt_nodatasum: 143 printk(KERN_INFO "btrfs: setting nodatasum\n"); 144 btrfs_set_opt(info->mount_opt, NODATASUM); 145 break; 146 case Opt_nodatacow: 147 printk(KERN_INFO "btrfs: setting nodatacow\n"); 148 btrfs_set_opt(info->mount_opt, NODATACOW); 149 btrfs_set_opt(info->mount_opt, NODATASUM); 150 break; 151 case Opt_compress: 152 printk(KERN_INFO "btrfs: use compression\n"); 153 btrfs_set_opt(info->mount_opt, COMPRESS); 154 break; 155 case Opt_compress_force: 156 printk(KERN_INFO "btrfs: forcing compression\n"); 157 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); 158 btrfs_set_opt(info->mount_opt, COMPRESS); 159 break; 160 case Opt_ssd: 161 printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); 162 btrfs_set_opt(info->mount_opt, SSD); 163 break; 164 case Opt_ssd_spread: 165 printk(KERN_INFO "btrfs: use spread ssd " 166 "allocation scheme\n"); 167 btrfs_set_opt(info->mount_opt, SSD); 168 btrfs_set_opt(info->mount_opt, SSD_SPREAD); 169 break; 170 case Opt_nossd: 171 printk(KERN_INFO "btrfs: not using ssd allocation " 172 "scheme\n"); 173 btrfs_set_opt(info->mount_opt, NOSSD); 174 btrfs_clear_opt(info->mount_opt, SSD); 175 btrfs_clear_opt(info->mount_opt, SSD_SPREAD); 176 break; 177 case Opt_nobarrier: 178 printk(KERN_INFO "btrfs: turning off barriers\n"); 179 btrfs_set_opt(info->mount_opt, NOBARRIER); 180 break; 181 case Opt_thread_pool: 182 intarg = 0; 183 match_int(&args[0], &intarg); 184 if (intarg) { 185 info->thread_pool_size = intarg; 186 printk(KERN_INFO "btrfs: thread pool %d\n", 187 info->thread_pool_size); 188 } 189 break; 190 case Opt_max_inline: 191 num = match_strdup(&args[0]); 192 if (num) { 193 info->max_inline = memparse(num, NULL); 194 kfree(num); 195 196 if (info->max_inline) { 197 info->max_inline = max_t(u64, 198 info->max_inline, 199 root->sectorsize); 200 } 201 printk(KERN_INFO "btrfs: max_inline at %llu\n", 202 (unsigned long long)info->max_inline); 203 } 204 break; 205 case Opt_alloc_start: 206 num = match_strdup(&args[0]); 207 if (num) { 208 info->alloc_start = memparse(num, NULL); 209 kfree(num); 210 printk(KERN_INFO 211 "btrfs: allocations start at %llu\n", 212 (unsigned long long)info->alloc_start); 213 } 214 break; 215 case Opt_noacl: 216 root->fs_info->sb->s_flags &= ~MS_POSIXACL; 217 break; 218 case Opt_notreelog: 219 printk(KERN_INFO "btrfs: disabling tree log\n"); 220 btrfs_set_opt(info->mount_opt, NOTREELOG); 221 break; 222 case Opt_flushoncommit: 223 printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); 224 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); 225 break; 226 case Opt_ratio: 227 intarg = 0; 228 match_int(&args[0], &intarg); 229 if (intarg) { 230 info->metadata_ratio = intarg; 231 printk(KERN_INFO "btrfs: metadata ratio %d\n", 232 info->metadata_ratio); 233 } 234 break; 235 case Opt_discard: 236 btrfs_set_opt(info->mount_opt, DISCARD); 237 break; 238 case Opt_err: 239 printk(KERN_INFO "btrfs: unrecognized mount option " 240 "'%s'\n", p); 241 ret = -EINVAL; 242 goto out; 243 default: 244 break; 245 } 246 } 247 out: 248 kfree(orig); 249 return ret; 250 } 251 252 /* 253 * Parse mount options that are required early in the mount process. 254 * 255 * All other options will be parsed on much later in the mount process and 256 * only when we need to allocate a new super block. 257 */ 258 static int btrfs_parse_early_options(const char *options, fmode_t flags, 259 void *holder, char **subvol_name, u64 *subvol_objectid, 260 struct btrfs_fs_devices **fs_devices) 261 { 262 substring_t args[MAX_OPT_ARGS]; 263 char *opts, *p; 264 int error = 0; 265 int intarg; 266 267 if (!options) 268 goto out; 269 270 /* 271 * strsep changes the string, duplicate it because parse_options 272 * gets called twice 273 */ 274 opts = kstrdup(options, GFP_KERNEL); 275 if (!opts) 276 return -ENOMEM; 277 278 while ((p = strsep(&opts, ",")) != NULL) { 279 int token; 280 if (!*p) 281 continue; 282 283 token = match_token(p, tokens, args); 284 switch (token) { 285 case Opt_subvol: 286 *subvol_name = match_strdup(&args[0]); 287 break; 288 case Opt_subvolid: 289 intarg = 0; 290 error = match_int(&args[0], &intarg); 291 if (!error) { 292 /* we want the original fs_tree */ 293 if (!intarg) 294 *subvol_objectid = 295 BTRFS_FS_TREE_OBJECTID; 296 else 297 *subvol_objectid = intarg; 298 } 299 break; 300 case Opt_device: 301 error = btrfs_scan_one_device(match_strdup(&args[0]), 302 flags, holder, fs_devices); 303 if (error) 304 goto out_free_opts; 305 break; 306 default: 307 break; 308 } 309 } 310 311 out_free_opts: 312 kfree(opts); 313 out: 314 /* 315 * If no subvolume name is specified we use the default one. Allocate 316 * a copy of the string "." here so that code later in the 317 * mount path doesn't care if it's the default volume or another one. 318 */ 319 if (!*subvol_name) { 320 *subvol_name = kstrdup(".", GFP_KERNEL); 321 if (!*subvol_name) 322 return -ENOMEM; 323 } 324 return error; 325 } 326 327 static struct dentry *get_default_root(struct super_block *sb, 328 u64 subvol_objectid) 329 { 330 struct btrfs_root *root = sb->s_fs_info; 331 struct btrfs_root *new_root; 332 struct btrfs_dir_item *di; 333 struct btrfs_path *path; 334 struct btrfs_key location; 335 struct inode *inode; 336 struct dentry *dentry; 337 u64 dir_id; 338 int new = 0; 339 340 /* 341 * We have a specific subvol we want to mount, just setup location and 342 * go look up the root. 343 */ 344 if (subvol_objectid) { 345 location.objectid = subvol_objectid; 346 location.type = BTRFS_ROOT_ITEM_KEY; 347 location.offset = (u64)-1; 348 goto find_root; 349 } 350 351 path = btrfs_alloc_path(); 352 if (!path) 353 return ERR_PTR(-ENOMEM); 354 path->leave_spinning = 1; 355 356 /* 357 * Find the "default" dir item which points to the root item that we 358 * will mount by default if we haven't been given a specific subvolume 359 * to mount. 360 */ 361 dir_id = btrfs_super_root_dir(&root->fs_info->super_copy); 362 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 363 if (!di) { 364 /* 365 * Ok the default dir item isn't there. This is weird since 366 * it's always been there, but don't freak out, just try and 367 * mount to root most subvolume. 368 */ 369 btrfs_free_path(path); 370 dir_id = BTRFS_FIRST_FREE_OBJECTID; 371 new_root = root->fs_info->fs_root; 372 goto setup_root; 373 } 374 375 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 376 btrfs_free_path(path); 377 378 find_root: 379 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); 380 if (IS_ERR(new_root)) 381 return ERR_PTR(PTR_ERR(new_root)); 382 383 if (btrfs_root_refs(&new_root->root_item) == 0) 384 return ERR_PTR(-ENOENT); 385 386 dir_id = btrfs_root_dirid(&new_root->root_item); 387 setup_root: 388 location.objectid = dir_id; 389 location.type = BTRFS_INODE_ITEM_KEY; 390 location.offset = 0; 391 392 inode = btrfs_iget(sb, &location, new_root, &new); 393 if (!inode) 394 return ERR_PTR(-ENOMEM); 395 396 /* 397 * If we're just mounting the root most subvol put the inode and return 398 * a reference to the dentry. We will have already gotten a reference 399 * to the inode in btrfs_fill_super so we're good to go. 400 */ 401 if (!new && sb->s_root->d_inode == inode) { 402 iput(inode); 403 return dget(sb->s_root); 404 } 405 406 if (new) { 407 const struct qstr name = { .name = "/", .len = 1 }; 408 409 /* 410 * New inode, we need to make the dentry a sibling of s_root so 411 * everything gets cleaned up properly on unmount. 412 */ 413 dentry = d_alloc(sb->s_root, &name); 414 if (!dentry) { 415 iput(inode); 416 return ERR_PTR(-ENOMEM); 417 } 418 d_splice_alias(inode, dentry); 419 } else { 420 /* 421 * We found the inode in cache, just find a dentry for it and 422 * put the reference to the inode we just got. 423 */ 424 dentry = d_find_alias(inode); 425 iput(inode); 426 } 427 428 return dentry; 429 } 430 431 static int btrfs_fill_super(struct super_block *sb, 432 struct btrfs_fs_devices *fs_devices, 433 void *data, int silent) 434 { 435 struct inode *inode; 436 struct dentry *root_dentry; 437 struct btrfs_super_block *disk_super; 438 struct btrfs_root *tree_root; 439 struct btrfs_key key; 440 int err; 441 442 sb->s_maxbytes = MAX_LFS_FILESIZE; 443 sb->s_magic = BTRFS_SUPER_MAGIC; 444 sb->s_op = &btrfs_super_ops; 445 sb->s_export_op = &btrfs_export_ops; 446 sb->s_xattr = btrfs_xattr_handlers; 447 sb->s_time_gran = 1; 448 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 449 sb->s_flags |= MS_POSIXACL; 450 #endif 451 452 tree_root = open_ctree(sb, fs_devices, (char *)data); 453 454 if (IS_ERR(tree_root)) { 455 printk("btrfs: open_ctree failed\n"); 456 return PTR_ERR(tree_root); 457 } 458 sb->s_fs_info = tree_root; 459 disk_super = &tree_root->fs_info->super_copy; 460 461 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 462 key.type = BTRFS_INODE_ITEM_KEY; 463 key.offset = 0; 464 inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL); 465 if (IS_ERR(inode)) { 466 err = PTR_ERR(inode); 467 goto fail_close; 468 } 469 470 root_dentry = d_alloc_root(inode); 471 if (!root_dentry) { 472 iput(inode); 473 err = -ENOMEM; 474 goto fail_close; 475 } 476 477 sb->s_root = root_dentry; 478 479 save_mount_options(sb, data); 480 return 0; 481 482 fail_close: 483 close_ctree(tree_root); 484 return err; 485 } 486 487 int btrfs_sync_fs(struct super_block *sb, int wait) 488 { 489 struct btrfs_trans_handle *trans; 490 struct btrfs_root *root = btrfs_sb(sb); 491 int ret; 492 493 if (!wait) { 494 filemap_flush(root->fs_info->btree_inode->i_mapping); 495 return 0; 496 } 497 498 btrfs_start_delalloc_inodes(root, 0); 499 btrfs_wait_ordered_extents(root, 0, 0); 500 501 trans = btrfs_start_transaction(root, 1); 502 ret = btrfs_commit_transaction(trans, root); 503 return ret; 504 } 505 506 static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) 507 { 508 struct btrfs_root *root = btrfs_sb(vfs->mnt_sb); 509 struct btrfs_fs_info *info = root->fs_info; 510 511 if (btrfs_test_opt(root, DEGRADED)) 512 seq_puts(seq, ",degraded"); 513 if (btrfs_test_opt(root, NODATASUM)) 514 seq_puts(seq, ",nodatasum"); 515 if (btrfs_test_opt(root, NODATACOW)) 516 seq_puts(seq, ",nodatacow"); 517 if (btrfs_test_opt(root, NOBARRIER)) 518 seq_puts(seq, ",nobarrier"); 519 if (info->max_inline != 8192 * 1024) 520 seq_printf(seq, ",max_inline=%llu", 521 (unsigned long long)info->max_inline); 522 if (info->alloc_start != 0) 523 seq_printf(seq, ",alloc_start=%llu", 524 (unsigned long long)info->alloc_start); 525 if (info->thread_pool_size != min_t(unsigned long, 526 num_online_cpus() + 2, 8)) 527 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 528 if (btrfs_test_opt(root, COMPRESS)) 529 seq_puts(seq, ",compress"); 530 if (btrfs_test_opt(root, NOSSD)) 531 seq_puts(seq, ",nossd"); 532 if (btrfs_test_opt(root, SSD_SPREAD)) 533 seq_puts(seq, ",ssd_spread"); 534 else if (btrfs_test_opt(root, SSD)) 535 seq_puts(seq, ",ssd"); 536 if (btrfs_test_opt(root, NOTREELOG)) 537 seq_puts(seq, ",notreelog"); 538 if (btrfs_test_opt(root, FLUSHONCOMMIT)) 539 seq_puts(seq, ",flushoncommit"); 540 if (btrfs_test_opt(root, DISCARD)) 541 seq_puts(seq, ",discard"); 542 if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) 543 seq_puts(seq, ",noacl"); 544 return 0; 545 } 546 547 static int btrfs_test_super(struct super_block *s, void *data) 548 { 549 struct btrfs_fs_devices *test_fs_devices = data; 550 struct btrfs_root *root = btrfs_sb(s); 551 552 return root->fs_info->fs_devices == test_fs_devices; 553 } 554 555 /* 556 * Find a superblock for the given device / mount point. 557 * 558 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 559 * for multiple device setup. Make sure to keep it in sync. 560 */ 561 static int btrfs_get_sb(struct file_system_type *fs_type, int flags, 562 const char *dev_name, void *data, struct vfsmount *mnt) 563 { 564 struct block_device *bdev = NULL; 565 struct super_block *s; 566 struct dentry *root; 567 struct btrfs_fs_devices *fs_devices = NULL; 568 fmode_t mode = FMODE_READ; 569 char *subvol_name = NULL; 570 u64 subvol_objectid = 0; 571 int error = 0; 572 int found = 0; 573 574 if (!(flags & MS_RDONLY)) 575 mode |= FMODE_WRITE; 576 577 error = btrfs_parse_early_options(data, mode, fs_type, 578 &subvol_name, &subvol_objectid, 579 &fs_devices); 580 if (error) 581 return error; 582 583 error = btrfs_scan_one_device(dev_name, mode, fs_type, &fs_devices); 584 if (error) 585 goto error_free_subvol_name; 586 587 error = btrfs_open_devices(fs_devices, mode, fs_type); 588 if (error) 589 goto error_free_subvol_name; 590 591 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 592 error = -EACCES; 593 goto error_close_devices; 594 } 595 596 bdev = fs_devices->latest_bdev; 597 s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices); 598 if (IS_ERR(s)) 599 goto error_s; 600 601 if (s->s_root) { 602 if ((flags ^ s->s_flags) & MS_RDONLY) { 603 deactivate_locked_super(s); 604 error = -EBUSY; 605 goto error_close_devices; 606 } 607 608 found = 1; 609 btrfs_close_devices(fs_devices); 610 } else { 611 char b[BDEVNAME_SIZE]; 612 613 s->s_flags = flags; 614 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); 615 error = btrfs_fill_super(s, fs_devices, data, 616 flags & MS_SILENT ? 1 : 0); 617 if (error) { 618 deactivate_locked_super(s); 619 goto error_free_subvol_name; 620 } 621 622 btrfs_sb(s)->fs_info->bdev_holder = fs_type; 623 s->s_flags |= MS_ACTIVE; 624 } 625 626 root = get_default_root(s, subvol_objectid); 627 if (IS_ERR(root)) { 628 error = PTR_ERR(root); 629 deactivate_locked_super(s); 630 goto error; 631 } 632 /* if they gave us a subvolume name bind mount into that */ 633 if (strcmp(subvol_name, ".")) { 634 struct dentry *new_root; 635 mutex_lock(&root->d_inode->i_mutex); 636 new_root = lookup_one_len(subvol_name, root, 637 strlen(subvol_name)); 638 mutex_unlock(&root->d_inode->i_mutex); 639 640 if (IS_ERR(new_root)) { 641 deactivate_locked_super(s); 642 error = PTR_ERR(new_root); 643 dput(root); 644 goto error_close_devices; 645 } 646 if (!new_root->d_inode) { 647 dput(root); 648 dput(new_root); 649 deactivate_locked_super(s); 650 error = -ENXIO; 651 goto error_close_devices; 652 } 653 dput(root); 654 root = new_root; 655 } 656 657 mnt->mnt_sb = s; 658 mnt->mnt_root = root; 659 660 kfree(subvol_name); 661 return 0; 662 663 error_s: 664 error = PTR_ERR(s); 665 error_close_devices: 666 btrfs_close_devices(fs_devices); 667 error_free_subvol_name: 668 kfree(subvol_name); 669 error: 670 return error; 671 } 672 673 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 674 { 675 struct btrfs_root *root = btrfs_sb(sb); 676 int ret; 677 678 ret = btrfs_parse_options(root, data); 679 if (ret) 680 return -EINVAL; 681 682 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 683 return 0; 684 685 if (*flags & MS_RDONLY) { 686 sb->s_flags |= MS_RDONLY; 687 688 ret = btrfs_commit_super(root); 689 WARN_ON(ret); 690 } else { 691 if (root->fs_info->fs_devices->rw_devices == 0) 692 return -EACCES; 693 694 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0) 695 return -EINVAL; 696 697 /* recover relocation */ 698 ret = btrfs_recover_relocation(root); 699 WARN_ON(ret); 700 701 ret = btrfs_cleanup_fs_roots(root->fs_info); 702 WARN_ON(ret); 703 704 sb->s_flags &= ~MS_RDONLY; 705 } 706 707 return 0; 708 } 709 710 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 711 { 712 struct btrfs_root *root = btrfs_sb(dentry->d_sb); 713 struct btrfs_super_block *disk_super = &root->fs_info->super_copy; 714 struct list_head *head = &root->fs_info->space_info; 715 struct btrfs_space_info *found; 716 u64 total_used = 0; 717 u64 data_used = 0; 718 int bits = dentry->d_sb->s_blocksize_bits; 719 __be32 *fsid = (__be32 *)root->fs_info->fsid; 720 721 rcu_read_lock(); 722 list_for_each_entry_rcu(found, head, list) { 723 if (found->flags & (BTRFS_BLOCK_GROUP_DUP| 724 BTRFS_BLOCK_GROUP_RAID10| 725 BTRFS_BLOCK_GROUP_RAID1)) { 726 total_used += found->bytes_used; 727 if (found->flags & BTRFS_BLOCK_GROUP_DATA) 728 data_used += found->bytes_used; 729 else 730 data_used += found->total_bytes; 731 } 732 733 total_used += found->bytes_used; 734 if (found->flags & BTRFS_BLOCK_GROUP_DATA) 735 data_used += found->bytes_used; 736 else 737 data_used += found->total_bytes; 738 } 739 rcu_read_unlock(); 740 741 buf->f_namelen = BTRFS_NAME_LEN; 742 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; 743 buf->f_bfree = buf->f_blocks - (total_used >> bits); 744 buf->f_bavail = buf->f_blocks - (data_used >> bits); 745 buf->f_bsize = dentry->d_sb->s_blocksize; 746 buf->f_type = BTRFS_SUPER_MAGIC; 747 748 /* We treat it as constant endianness (it doesn't matter _which_) 749 because we want the fsid to come out the same whether mounted 750 on a big-endian or little-endian host */ 751 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 752 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 753 /* Mask in the root object ID too, to disambiguate subvols */ 754 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; 755 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; 756 757 return 0; 758 } 759 760 static struct file_system_type btrfs_fs_type = { 761 .owner = THIS_MODULE, 762 .name = "btrfs", 763 .get_sb = btrfs_get_sb, 764 .kill_sb = kill_anon_super, 765 .fs_flags = FS_REQUIRES_DEV, 766 }; 767 768 /* 769 * used by btrfsctl to scan devices when no FS is mounted 770 */ 771 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 772 unsigned long arg) 773 { 774 struct btrfs_ioctl_vol_args *vol; 775 struct btrfs_fs_devices *fs_devices; 776 int ret = -ENOTTY; 777 778 if (!capable(CAP_SYS_ADMIN)) 779 return -EPERM; 780 781 vol = memdup_user((void __user *)arg, sizeof(*vol)); 782 if (IS_ERR(vol)) 783 return PTR_ERR(vol); 784 785 switch (cmd) { 786 case BTRFS_IOC_SCAN_DEV: 787 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 788 &btrfs_fs_type, &fs_devices); 789 break; 790 } 791 792 kfree(vol); 793 return ret; 794 } 795 796 static int btrfs_freeze(struct super_block *sb) 797 { 798 struct btrfs_root *root = btrfs_sb(sb); 799 mutex_lock(&root->fs_info->transaction_kthread_mutex); 800 mutex_lock(&root->fs_info->cleaner_mutex); 801 return 0; 802 } 803 804 static int btrfs_unfreeze(struct super_block *sb) 805 { 806 struct btrfs_root *root = btrfs_sb(sb); 807 mutex_unlock(&root->fs_info->cleaner_mutex); 808 mutex_unlock(&root->fs_info->transaction_kthread_mutex); 809 return 0; 810 } 811 812 static const struct super_operations btrfs_super_ops = { 813 .drop_inode = btrfs_drop_inode, 814 .delete_inode = btrfs_delete_inode, 815 .put_super = btrfs_put_super, 816 .sync_fs = btrfs_sync_fs, 817 .show_options = btrfs_show_options, 818 .write_inode = btrfs_write_inode, 819 .dirty_inode = btrfs_dirty_inode, 820 .alloc_inode = btrfs_alloc_inode, 821 .destroy_inode = btrfs_destroy_inode, 822 .statfs = btrfs_statfs, 823 .remount_fs = btrfs_remount, 824 .freeze_fs = btrfs_freeze, 825 .unfreeze_fs = btrfs_unfreeze, 826 }; 827 828 static const struct file_operations btrfs_ctl_fops = { 829 .unlocked_ioctl = btrfs_control_ioctl, 830 .compat_ioctl = btrfs_control_ioctl, 831 .owner = THIS_MODULE, 832 }; 833 834 static struct miscdevice btrfs_misc = { 835 .minor = MISC_DYNAMIC_MINOR, 836 .name = "btrfs-control", 837 .fops = &btrfs_ctl_fops 838 }; 839 840 static int btrfs_interface_init(void) 841 { 842 return misc_register(&btrfs_misc); 843 } 844 845 static void btrfs_interface_exit(void) 846 { 847 if (misc_deregister(&btrfs_misc) < 0) 848 printk(KERN_INFO "misc_deregister failed for control device"); 849 } 850 851 static int __init init_btrfs_fs(void) 852 { 853 int err; 854 855 err = btrfs_init_sysfs(); 856 if (err) 857 return err; 858 859 err = btrfs_init_cachep(); 860 if (err) 861 goto free_sysfs; 862 863 err = extent_io_init(); 864 if (err) 865 goto free_cachep; 866 867 err = extent_map_init(); 868 if (err) 869 goto free_extent_io; 870 871 err = btrfs_interface_init(); 872 if (err) 873 goto free_extent_map; 874 875 err = register_filesystem(&btrfs_fs_type); 876 if (err) 877 goto unregister_ioctl; 878 879 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); 880 return 0; 881 882 unregister_ioctl: 883 btrfs_interface_exit(); 884 free_extent_map: 885 extent_map_exit(); 886 free_extent_io: 887 extent_io_exit(); 888 free_cachep: 889 btrfs_destroy_cachep(); 890 free_sysfs: 891 btrfs_exit_sysfs(); 892 return err; 893 } 894 895 static void __exit exit_btrfs_fs(void) 896 { 897 btrfs_destroy_cachep(); 898 extent_map_exit(); 899 extent_io_exit(); 900 btrfs_interface_exit(); 901 unregister_filesystem(&btrfs_fs_type); 902 btrfs_exit_sysfs(); 903 btrfs_cleanup_fs_uuids(); 904 btrfs_zlib_exit(); 905 } 906 907 module_init(init_btrfs_fs) 908 module_exit(exit_btrfs_fs) 909 910 MODULE_LICENSE("GPL"); 911