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 <linux/cleancache.h> 43 #include <linux/mnt_namespace.h> 44 #include "compat.h" 45 #include "delayed-inode.h" 46 #include "ctree.h" 47 #include "disk-io.h" 48 #include "transaction.h" 49 #include "btrfs_inode.h" 50 #include "ioctl.h" 51 #include "print-tree.h" 52 #include "xattr.h" 53 #include "volumes.h" 54 #include "version.h" 55 #include "export.h" 56 #include "compression.h" 57 58 #define CREATE_TRACE_POINTS 59 #include <trace/events/btrfs.h> 60 61 static const struct super_operations btrfs_super_ops; 62 static struct file_system_type btrfs_fs_type; 63 64 static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno, 65 char nbuf[16]) 66 { 67 char *errstr = NULL; 68 69 switch (errno) { 70 case -EIO: 71 errstr = "IO failure"; 72 break; 73 case -ENOMEM: 74 errstr = "Out of memory"; 75 break; 76 case -EROFS: 77 errstr = "Readonly filesystem"; 78 break; 79 default: 80 if (nbuf) { 81 if (snprintf(nbuf, 16, "error %d", -errno) >= 0) 82 errstr = nbuf; 83 } 84 break; 85 } 86 87 return errstr; 88 } 89 90 static void __save_error_info(struct btrfs_fs_info *fs_info) 91 { 92 /* 93 * today we only save the error info into ram. Long term we'll 94 * also send it down to the disk 95 */ 96 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR; 97 } 98 99 /* NOTE: 100 * We move write_super stuff at umount in order to avoid deadlock 101 * for umount hold all lock. 102 */ 103 static void save_error_info(struct btrfs_fs_info *fs_info) 104 { 105 __save_error_info(fs_info); 106 } 107 108 /* btrfs handle error by forcing the filesystem readonly */ 109 static void btrfs_handle_error(struct btrfs_fs_info *fs_info) 110 { 111 struct super_block *sb = fs_info->sb; 112 113 if (sb->s_flags & MS_RDONLY) 114 return; 115 116 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { 117 sb->s_flags |= MS_RDONLY; 118 printk(KERN_INFO "btrfs is forced readonly\n"); 119 } 120 } 121 122 /* 123 * __btrfs_std_error decodes expected errors from the caller and 124 * invokes the approciate error response. 125 */ 126 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, 127 unsigned int line, int errno) 128 { 129 struct super_block *sb = fs_info->sb; 130 char nbuf[16]; 131 const char *errstr; 132 133 /* 134 * Special case: if the error is EROFS, and we're already 135 * under MS_RDONLY, then it is safe here. 136 */ 137 if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) 138 return; 139 140 errstr = btrfs_decode_error(fs_info, errno, nbuf); 141 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n", 142 sb->s_id, function, line, errstr); 143 save_error_info(fs_info); 144 145 btrfs_handle_error(fs_info); 146 } 147 148 static void btrfs_put_super(struct super_block *sb) 149 { 150 struct btrfs_root *root = btrfs_sb(sb); 151 int ret; 152 153 ret = close_ctree(root); 154 sb->s_fs_info = NULL; 155 156 (void)ret; /* FIXME: need to fix VFS to return error? */ 157 } 158 159 enum { 160 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, 161 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, 162 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, 163 Opt_compress_type, Opt_compress_force, Opt_compress_force_type, 164 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, 165 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, 166 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, 167 Opt_inode_cache, Opt_no_space_cache, Opt_recovery, Opt_err, 168 }; 169 170 static match_table_t tokens = { 171 {Opt_degraded, "degraded"}, 172 {Opt_subvol, "subvol=%s"}, 173 {Opt_subvolid, "subvolid=%d"}, 174 {Opt_device, "device=%s"}, 175 {Opt_nodatasum, "nodatasum"}, 176 {Opt_nodatacow, "nodatacow"}, 177 {Opt_nobarrier, "nobarrier"}, 178 {Opt_max_inline, "max_inline=%s"}, 179 {Opt_alloc_start, "alloc_start=%s"}, 180 {Opt_thread_pool, "thread_pool=%d"}, 181 {Opt_compress, "compress"}, 182 {Opt_compress_type, "compress=%s"}, 183 {Opt_compress_force, "compress-force"}, 184 {Opt_compress_force_type, "compress-force=%s"}, 185 {Opt_ssd, "ssd"}, 186 {Opt_ssd_spread, "ssd_spread"}, 187 {Opt_nossd, "nossd"}, 188 {Opt_noacl, "noacl"}, 189 {Opt_notreelog, "notreelog"}, 190 {Opt_flushoncommit, "flushoncommit"}, 191 {Opt_ratio, "metadata_ratio=%d"}, 192 {Opt_discard, "discard"}, 193 {Opt_space_cache, "space_cache"}, 194 {Opt_clear_cache, "clear_cache"}, 195 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, 196 {Opt_enospc_debug, "enospc_debug"}, 197 {Opt_subvolrootid, "subvolrootid=%d"}, 198 {Opt_defrag, "autodefrag"}, 199 {Opt_inode_cache, "inode_cache"}, 200 {Opt_no_space_cache, "nospace_cache"}, 201 {Opt_recovery, "recovery"}, 202 {Opt_err, NULL}, 203 }; 204 205 /* 206 * Regular mount options parser. Everything that is needed only when 207 * reading in a new superblock is parsed here. 208 */ 209 int btrfs_parse_options(struct btrfs_root *root, char *options) 210 { 211 struct btrfs_fs_info *info = root->fs_info; 212 substring_t args[MAX_OPT_ARGS]; 213 char *p, *num, *orig = NULL; 214 u64 cache_gen; 215 int intarg; 216 int ret = 0; 217 char *compress_type; 218 bool compress_force = false; 219 220 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); 221 if (cache_gen) 222 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 223 224 if (!options) 225 goto out; 226 227 /* 228 * strsep changes the string, duplicate it because parse_options 229 * gets called twice 230 */ 231 options = kstrdup(options, GFP_NOFS); 232 if (!options) 233 return -ENOMEM; 234 235 orig = options; 236 237 while ((p = strsep(&options, ",")) != NULL) { 238 int token; 239 if (!*p) 240 continue; 241 242 token = match_token(p, tokens, args); 243 switch (token) { 244 case Opt_degraded: 245 printk(KERN_INFO "btrfs: allowing degraded mounts\n"); 246 btrfs_set_opt(info->mount_opt, DEGRADED); 247 break; 248 case Opt_subvol: 249 case Opt_subvolid: 250 case Opt_subvolrootid: 251 case Opt_device: 252 /* 253 * These are parsed by btrfs_parse_early_options 254 * and can be happily ignored here. 255 */ 256 break; 257 case Opt_nodatasum: 258 printk(KERN_INFO "btrfs: setting nodatasum\n"); 259 btrfs_set_opt(info->mount_opt, NODATASUM); 260 break; 261 case Opt_nodatacow: 262 printk(KERN_INFO "btrfs: setting nodatacow\n"); 263 btrfs_set_opt(info->mount_opt, NODATACOW); 264 btrfs_set_opt(info->mount_opt, NODATASUM); 265 break; 266 case Opt_compress_force: 267 case Opt_compress_force_type: 268 compress_force = true; 269 case Opt_compress: 270 case Opt_compress_type: 271 if (token == Opt_compress || 272 token == Opt_compress_force || 273 strcmp(args[0].from, "zlib") == 0) { 274 compress_type = "zlib"; 275 info->compress_type = BTRFS_COMPRESS_ZLIB; 276 } else if (strcmp(args[0].from, "lzo") == 0) { 277 compress_type = "lzo"; 278 info->compress_type = BTRFS_COMPRESS_LZO; 279 } else { 280 ret = -EINVAL; 281 goto out; 282 } 283 284 btrfs_set_opt(info->mount_opt, COMPRESS); 285 if (compress_force) { 286 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); 287 pr_info("btrfs: force %s compression\n", 288 compress_type); 289 } else 290 pr_info("btrfs: use %s compression\n", 291 compress_type); 292 break; 293 case Opt_ssd: 294 printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); 295 btrfs_set_opt(info->mount_opt, SSD); 296 break; 297 case Opt_ssd_spread: 298 printk(KERN_INFO "btrfs: use spread ssd " 299 "allocation scheme\n"); 300 btrfs_set_opt(info->mount_opt, SSD); 301 btrfs_set_opt(info->mount_opt, SSD_SPREAD); 302 break; 303 case Opt_nossd: 304 printk(KERN_INFO "btrfs: not using ssd allocation " 305 "scheme\n"); 306 btrfs_set_opt(info->mount_opt, NOSSD); 307 btrfs_clear_opt(info->mount_opt, SSD); 308 btrfs_clear_opt(info->mount_opt, SSD_SPREAD); 309 break; 310 case Opt_nobarrier: 311 printk(KERN_INFO "btrfs: turning off barriers\n"); 312 btrfs_set_opt(info->mount_opt, NOBARRIER); 313 break; 314 case Opt_thread_pool: 315 intarg = 0; 316 match_int(&args[0], &intarg); 317 if (intarg) { 318 info->thread_pool_size = intarg; 319 printk(KERN_INFO "btrfs: thread pool %d\n", 320 info->thread_pool_size); 321 } 322 break; 323 case Opt_max_inline: 324 num = match_strdup(&args[0]); 325 if (num) { 326 info->max_inline = memparse(num, NULL); 327 kfree(num); 328 329 if (info->max_inline) { 330 info->max_inline = max_t(u64, 331 info->max_inline, 332 root->sectorsize); 333 } 334 printk(KERN_INFO "btrfs: max_inline at %llu\n", 335 (unsigned long long)info->max_inline); 336 } 337 break; 338 case Opt_alloc_start: 339 num = match_strdup(&args[0]); 340 if (num) { 341 info->alloc_start = memparse(num, NULL); 342 kfree(num); 343 printk(KERN_INFO 344 "btrfs: allocations start at %llu\n", 345 (unsigned long long)info->alloc_start); 346 } 347 break; 348 case Opt_noacl: 349 root->fs_info->sb->s_flags &= ~MS_POSIXACL; 350 break; 351 case Opt_notreelog: 352 printk(KERN_INFO "btrfs: disabling tree log\n"); 353 btrfs_set_opt(info->mount_opt, NOTREELOG); 354 break; 355 case Opt_flushoncommit: 356 printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); 357 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); 358 break; 359 case Opt_ratio: 360 intarg = 0; 361 match_int(&args[0], &intarg); 362 if (intarg) { 363 info->metadata_ratio = intarg; 364 printk(KERN_INFO "btrfs: metadata ratio %d\n", 365 info->metadata_ratio); 366 } 367 break; 368 case Opt_discard: 369 btrfs_set_opt(info->mount_opt, DISCARD); 370 break; 371 case Opt_space_cache: 372 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 373 break; 374 case Opt_no_space_cache: 375 printk(KERN_INFO "btrfs: disabling disk space caching\n"); 376 btrfs_clear_opt(info->mount_opt, SPACE_CACHE); 377 break; 378 case Opt_inode_cache: 379 printk(KERN_INFO "btrfs: enabling inode map caching\n"); 380 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE); 381 break; 382 case Opt_clear_cache: 383 printk(KERN_INFO "btrfs: force clearing of disk cache\n"); 384 btrfs_set_opt(info->mount_opt, CLEAR_CACHE); 385 break; 386 case Opt_user_subvol_rm_allowed: 387 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 388 break; 389 case Opt_enospc_debug: 390 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 391 break; 392 case Opt_defrag: 393 printk(KERN_INFO "btrfs: enabling auto defrag"); 394 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG); 395 break; 396 case Opt_recovery: 397 printk(KERN_INFO "btrfs: enabling auto recovery"); 398 btrfs_set_opt(info->mount_opt, RECOVERY); 399 break; 400 case Opt_err: 401 printk(KERN_INFO "btrfs: unrecognized mount option " 402 "'%s'\n", p); 403 ret = -EINVAL; 404 goto out; 405 default: 406 break; 407 } 408 } 409 out: 410 if (!ret && btrfs_test_opt(root, SPACE_CACHE)) 411 printk(KERN_INFO "btrfs: disk space caching is enabled\n"); 412 kfree(orig); 413 return ret; 414 } 415 416 /* 417 * Parse mount options that are required early in the mount process. 418 * 419 * All other options will be parsed on much later in the mount process and 420 * only when we need to allocate a new super block. 421 */ 422 static int btrfs_parse_early_options(const char *options, fmode_t flags, 423 void *holder, char **subvol_name, u64 *subvol_objectid, 424 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices) 425 { 426 substring_t args[MAX_OPT_ARGS]; 427 char *device_name, *opts, *orig, *p; 428 int error = 0; 429 int intarg; 430 431 if (!options) 432 return 0; 433 434 /* 435 * strsep changes the string, duplicate it because parse_options 436 * gets called twice 437 */ 438 opts = kstrdup(options, GFP_KERNEL); 439 if (!opts) 440 return -ENOMEM; 441 orig = opts; 442 443 while ((p = strsep(&opts, ",")) != NULL) { 444 int token; 445 if (!*p) 446 continue; 447 448 token = match_token(p, tokens, args); 449 switch (token) { 450 case Opt_subvol: 451 kfree(*subvol_name); 452 *subvol_name = match_strdup(&args[0]); 453 break; 454 case Opt_subvolid: 455 intarg = 0; 456 error = match_int(&args[0], &intarg); 457 if (!error) { 458 /* we want the original fs_tree */ 459 if (!intarg) 460 *subvol_objectid = 461 BTRFS_FS_TREE_OBJECTID; 462 else 463 *subvol_objectid = intarg; 464 } 465 break; 466 case Opt_subvolrootid: 467 intarg = 0; 468 error = match_int(&args[0], &intarg); 469 if (!error) { 470 /* we want the original fs_tree */ 471 if (!intarg) 472 *subvol_rootid = 473 BTRFS_FS_TREE_OBJECTID; 474 else 475 *subvol_rootid = intarg; 476 } 477 break; 478 case Opt_device: 479 device_name = match_strdup(&args[0]); 480 if (!device_name) { 481 error = -ENOMEM; 482 goto out; 483 } 484 error = btrfs_scan_one_device(device_name, 485 flags, holder, fs_devices); 486 kfree(device_name); 487 if (error) 488 goto out; 489 break; 490 default: 491 break; 492 } 493 } 494 495 out: 496 kfree(orig); 497 return error; 498 } 499 500 static struct dentry *get_default_root(struct super_block *sb, 501 u64 subvol_objectid) 502 { 503 struct btrfs_root *root = sb->s_fs_info; 504 struct btrfs_root *new_root; 505 struct btrfs_dir_item *di; 506 struct btrfs_path *path; 507 struct btrfs_key location; 508 struct inode *inode; 509 u64 dir_id; 510 int new = 0; 511 512 /* 513 * We have a specific subvol we want to mount, just setup location and 514 * go look up the root. 515 */ 516 if (subvol_objectid) { 517 location.objectid = subvol_objectid; 518 location.type = BTRFS_ROOT_ITEM_KEY; 519 location.offset = (u64)-1; 520 goto find_root; 521 } 522 523 path = btrfs_alloc_path(); 524 if (!path) 525 return ERR_PTR(-ENOMEM); 526 path->leave_spinning = 1; 527 528 /* 529 * Find the "default" dir item which points to the root item that we 530 * will mount by default if we haven't been given a specific subvolume 531 * to mount. 532 */ 533 dir_id = btrfs_super_root_dir(root->fs_info->super_copy); 534 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 535 if (IS_ERR(di)) { 536 btrfs_free_path(path); 537 return ERR_CAST(di); 538 } 539 if (!di) { 540 /* 541 * Ok the default dir item isn't there. This is weird since 542 * it's always been there, but don't freak out, just try and 543 * mount to root most subvolume. 544 */ 545 btrfs_free_path(path); 546 dir_id = BTRFS_FIRST_FREE_OBJECTID; 547 new_root = root->fs_info->fs_root; 548 goto setup_root; 549 } 550 551 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 552 btrfs_free_path(path); 553 554 find_root: 555 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); 556 if (IS_ERR(new_root)) 557 return ERR_CAST(new_root); 558 559 if (btrfs_root_refs(&new_root->root_item) == 0) 560 return ERR_PTR(-ENOENT); 561 562 dir_id = btrfs_root_dirid(&new_root->root_item); 563 setup_root: 564 location.objectid = dir_id; 565 location.type = BTRFS_INODE_ITEM_KEY; 566 location.offset = 0; 567 568 inode = btrfs_iget(sb, &location, new_root, &new); 569 if (IS_ERR(inode)) 570 return ERR_CAST(inode); 571 572 /* 573 * If we're just mounting the root most subvol put the inode and return 574 * a reference to the dentry. We will have already gotten a reference 575 * to the inode in btrfs_fill_super so we're good to go. 576 */ 577 if (!new && sb->s_root->d_inode == inode) { 578 iput(inode); 579 return dget(sb->s_root); 580 } 581 582 return d_obtain_alias(inode); 583 } 584 585 static int btrfs_fill_super(struct super_block *sb, 586 struct btrfs_fs_devices *fs_devices, 587 void *data, int silent) 588 { 589 struct inode *inode; 590 struct dentry *root_dentry; 591 struct btrfs_root *tree_root; 592 struct btrfs_key key; 593 int err; 594 595 sb->s_maxbytes = MAX_LFS_FILESIZE; 596 sb->s_magic = BTRFS_SUPER_MAGIC; 597 sb->s_op = &btrfs_super_ops; 598 sb->s_d_op = &btrfs_dentry_operations; 599 sb->s_export_op = &btrfs_export_ops; 600 sb->s_xattr = btrfs_xattr_handlers; 601 sb->s_time_gran = 1; 602 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 603 sb->s_flags |= MS_POSIXACL; 604 #endif 605 606 tree_root = open_ctree(sb, fs_devices, (char *)data); 607 608 if (IS_ERR(tree_root)) { 609 printk("btrfs: open_ctree failed\n"); 610 return PTR_ERR(tree_root); 611 } 612 sb->s_fs_info = tree_root; 613 614 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 615 key.type = BTRFS_INODE_ITEM_KEY; 616 key.offset = 0; 617 inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL); 618 if (IS_ERR(inode)) { 619 err = PTR_ERR(inode); 620 goto fail_close; 621 } 622 623 root_dentry = d_alloc_root(inode); 624 if (!root_dentry) { 625 iput(inode); 626 err = -ENOMEM; 627 goto fail_close; 628 } 629 630 sb->s_root = root_dentry; 631 632 save_mount_options(sb, data); 633 cleancache_init_fs(sb); 634 return 0; 635 636 fail_close: 637 close_ctree(tree_root); 638 return err; 639 } 640 641 int btrfs_sync_fs(struct super_block *sb, int wait) 642 { 643 struct btrfs_trans_handle *trans; 644 struct btrfs_root *root = btrfs_sb(sb); 645 int ret; 646 647 trace_btrfs_sync_fs(wait); 648 649 if (!wait) { 650 filemap_flush(root->fs_info->btree_inode->i_mapping); 651 return 0; 652 } 653 654 btrfs_start_delalloc_inodes(root, 0); 655 btrfs_wait_ordered_extents(root, 0, 0); 656 657 trans = btrfs_start_transaction(root, 0); 658 if (IS_ERR(trans)) 659 return PTR_ERR(trans); 660 ret = btrfs_commit_transaction(trans, root); 661 return ret; 662 } 663 664 static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) 665 { 666 struct btrfs_root *root = btrfs_sb(vfs->mnt_sb); 667 struct btrfs_fs_info *info = root->fs_info; 668 char *compress_type; 669 670 if (btrfs_test_opt(root, DEGRADED)) 671 seq_puts(seq, ",degraded"); 672 if (btrfs_test_opt(root, NODATASUM)) 673 seq_puts(seq, ",nodatasum"); 674 if (btrfs_test_opt(root, NODATACOW)) 675 seq_puts(seq, ",nodatacow"); 676 if (btrfs_test_opt(root, NOBARRIER)) 677 seq_puts(seq, ",nobarrier"); 678 if (info->max_inline != 8192 * 1024) 679 seq_printf(seq, ",max_inline=%llu", 680 (unsigned long long)info->max_inline); 681 if (info->alloc_start != 0) 682 seq_printf(seq, ",alloc_start=%llu", 683 (unsigned long long)info->alloc_start); 684 if (info->thread_pool_size != min_t(unsigned long, 685 num_online_cpus() + 2, 8)) 686 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 687 if (btrfs_test_opt(root, COMPRESS)) { 688 if (info->compress_type == BTRFS_COMPRESS_ZLIB) 689 compress_type = "zlib"; 690 else 691 compress_type = "lzo"; 692 if (btrfs_test_opt(root, FORCE_COMPRESS)) 693 seq_printf(seq, ",compress-force=%s", compress_type); 694 else 695 seq_printf(seq, ",compress=%s", compress_type); 696 } 697 if (btrfs_test_opt(root, NOSSD)) 698 seq_puts(seq, ",nossd"); 699 if (btrfs_test_opt(root, SSD_SPREAD)) 700 seq_puts(seq, ",ssd_spread"); 701 else if (btrfs_test_opt(root, SSD)) 702 seq_puts(seq, ",ssd"); 703 if (btrfs_test_opt(root, NOTREELOG)) 704 seq_puts(seq, ",notreelog"); 705 if (btrfs_test_opt(root, FLUSHONCOMMIT)) 706 seq_puts(seq, ",flushoncommit"); 707 if (btrfs_test_opt(root, DISCARD)) 708 seq_puts(seq, ",discard"); 709 if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) 710 seq_puts(seq, ",noacl"); 711 if (btrfs_test_opt(root, SPACE_CACHE)) 712 seq_puts(seq, ",space_cache"); 713 else 714 seq_puts(seq, ",nospace_cache"); 715 if (btrfs_test_opt(root, CLEAR_CACHE)) 716 seq_puts(seq, ",clear_cache"); 717 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 718 seq_puts(seq, ",user_subvol_rm_allowed"); 719 if (btrfs_test_opt(root, ENOSPC_DEBUG)) 720 seq_puts(seq, ",enospc_debug"); 721 if (btrfs_test_opt(root, AUTO_DEFRAG)) 722 seq_puts(seq, ",autodefrag"); 723 if (btrfs_test_opt(root, INODE_MAP_CACHE)) 724 seq_puts(seq, ",inode_cache"); 725 return 0; 726 } 727 728 static int btrfs_test_super(struct super_block *s, void *data) 729 { 730 struct btrfs_root *test_root = data; 731 struct btrfs_root *root = btrfs_sb(s); 732 733 /* 734 * If this super block is going away, return false as it 735 * can't match as an existing super block. 736 */ 737 if (!atomic_read(&s->s_active)) 738 return 0; 739 return root->fs_info->fs_devices == test_root->fs_info->fs_devices; 740 } 741 742 static int btrfs_set_super(struct super_block *s, void *data) 743 { 744 s->s_fs_info = data; 745 746 return set_anon_super(s, data); 747 } 748 749 /* 750 * subvolumes are identified by ino 256 751 */ 752 static inline int is_subvolume_inode(struct inode *inode) 753 { 754 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 755 return 1; 756 return 0; 757 } 758 759 /* 760 * This will strip out the subvol=%s argument for an argument string and add 761 * subvolid=0 to make sure we get the actual tree root for path walking to the 762 * subvol we want. 763 */ 764 static char *setup_root_args(char *args) 765 { 766 unsigned copied = 0; 767 unsigned len = strlen(args) + 2; 768 char *pos; 769 char *ret; 770 771 /* 772 * We need the same args as before, but minus 773 * 774 * subvol=a 775 * 776 * and add 777 * 778 * subvolid=0 779 * 780 * which is a difference of 2 characters, so we allocate strlen(args) + 781 * 2 characters. 782 */ 783 ret = kzalloc(len * sizeof(char), GFP_NOFS); 784 if (!ret) 785 return NULL; 786 pos = strstr(args, "subvol="); 787 788 /* This shouldn't happen, but just in case.. */ 789 if (!pos) { 790 kfree(ret); 791 return NULL; 792 } 793 794 /* 795 * The subvol=<> arg is not at the front of the string, copy everybody 796 * up to that into ret. 797 */ 798 if (pos != args) { 799 *pos = '\0'; 800 strcpy(ret, args); 801 copied += strlen(args); 802 pos++; 803 } 804 805 strncpy(ret + copied, "subvolid=0", len - copied); 806 807 /* Length of subvolid=0 */ 808 copied += 10; 809 810 /* 811 * If there is no , after the subvol= option then we know there's no 812 * other options and we can just return. 813 */ 814 pos = strchr(pos, ','); 815 if (!pos) 816 return ret; 817 818 /* Copy the rest of the arguments into our buffer */ 819 strncpy(ret + copied, pos, len - copied); 820 copied += strlen(pos); 821 822 return ret; 823 } 824 825 static struct dentry *mount_subvol(const char *subvol_name, int flags, 826 const char *device_name, char *data) 827 { 828 struct super_block *s; 829 struct dentry *root; 830 struct vfsmount *mnt; 831 struct mnt_namespace *ns_private; 832 char *newargs; 833 struct path path; 834 int error; 835 836 newargs = setup_root_args(data); 837 if (!newargs) 838 return ERR_PTR(-ENOMEM); 839 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, 840 newargs); 841 kfree(newargs); 842 if (IS_ERR(mnt)) 843 return ERR_CAST(mnt); 844 845 ns_private = create_mnt_ns(mnt); 846 if (IS_ERR(ns_private)) { 847 mntput(mnt); 848 return ERR_CAST(ns_private); 849 } 850 851 /* 852 * This will trigger the automount of the subvol so we can just 853 * drop the mnt we have here and return the dentry that we 854 * found. 855 */ 856 error = vfs_path_lookup(mnt->mnt_root, mnt, subvol_name, 857 LOOKUP_FOLLOW, &path); 858 put_mnt_ns(ns_private); 859 if (error) 860 return ERR_PTR(error); 861 862 if (!is_subvolume_inode(path.dentry->d_inode)) { 863 path_put(&path); 864 mntput(mnt); 865 error = -EINVAL; 866 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n", 867 subvol_name); 868 return ERR_PTR(-EINVAL); 869 } 870 871 /* Get a ref to the sb and the dentry we found and return it */ 872 s = path.mnt->mnt_sb; 873 atomic_inc(&s->s_active); 874 root = dget(path.dentry); 875 path_put(&path); 876 down_write(&s->s_umount); 877 878 return root; 879 } 880 881 /* 882 * Find a superblock for the given device / mount point. 883 * 884 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 885 * for multiple device setup. Make sure to keep it in sync. 886 */ 887 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 888 const char *device_name, void *data) 889 { 890 struct block_device *bdev = NULL; 891 struct super_block *s; 892 struct dentry *root; 893 struct btrfs_fs_devices *fs_devices = NULL; 894 struct btrfs_fs_info *fs_info = NULL; 895 fmode_t mode = FMODE_READ; 896 char *subvol_name = NULL; 897 u64 subvol_objectid = 0; 898 u64 subvol_rootid = 0; 899 int error = 0; 900 901 if (!(flags & MS_RDONLY)) 902 mode |= FMODE_WRITE; 903 904 error = btrfs_parse_early_options(data, mode, fs_type, 905 &subvol_name, &subvol_objectid, 906 &subvol_rootid, &fs_devices); 907 if (error) { 908 kfree(subvol_name); 909 return ERR_PTR(error); 910 } 911 912 if (subvol_name) { 913 root = mount_subvol(subvol_name, flags, device_name, data); 914 kfree(subvol_name); 915 return root; 916 } 917 918 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); 919 if (error) 920 return ERR_PTR(error); 921 922 /* 923 * Setup a dummy root and fs_info for test/set super. This is because 924 * we don't actually fill this stuff out until open_ctree, but we need 925 * it for searching for existing supers, so this lets us do that and 926 * then open_ctree will properly initialize everything later. 927 */ 928 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); 929 if (!fs_info) 930 return ERR_PTR(-ENOMEM); 931 932 fs_info->tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); 933 if (!fs_info->tree_root) { 934 error = -ENOMEM; 935 goto error_fs_info; 936 } 937 fs_info->tree_root->fs_info = fs_info; 938 fs_info->fs_devices = fs_devices; 939 940 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 941 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 942 if (!fs_info->super_copy || !fs_info->super_for_commit) { 943 error = -ENOMEM; 944 goto error_fs_info; 945 } 946 947 error = btrfs_open_devices(fs_devices, mode, fs_type); 948 if (error) 949 goto error_fs_info; 950 951 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 952 error = -EACCES; 953 goto error_close_devices; 954 } 955 956 bdev = fs_devices->latest_bdev; 957 s = sget(fs_type, btrfs_test_super, btrfs_set_super, 958 fs_info->tree_root); 959 if (IS_ERR(s)) { 960 error = PTR_ERR(s); 961 goto error_close_devices; 962 } 963 964 if (s->s_root) { 965 if ((flags ^ s->s_flags) & MS_RDONLY) { 966 deactivate_locked_super(s); 967 error = -EBUSY; 968 goto error_close_devices; 969 } 970 971 btrfs_close_devices(fs_devices); 972 free_fs_info(fs_info); 973 } else { 974 char b[BDEVNAME_SIZE]; 975 976 s->s_flags = flags | MS_NOSEC; 977 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); 978 btrfs_sb(s)->fs_info->bdev_holder = fs_type; 979 error = btrfs_fill_super(s, fs_devices, data, 980 flags & MS_SILENT ? 1 : 0); 981 if (error) { 982 deactivate_locked_super(s); 983 return ERR_PTR(error); 984 } 985 986 s->s_flags |= MS_ACTIVE; 987 } 988 989 root = get_default_root(s, subvol_objectid); 990 if (IS_ERR(root)) { 991 deactivate_locked_super(s); 992 return root; 993 } 994 995 return root; 996 997 error_close_devices: 998 btrfs_close_devices(fs_devices); 999 error_fs_info: 1000 free_fs_info(fs_info); 1001 return ERR_PTR(error); 1002 } 1003 1004 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1005 { 1006 struct btrfs_root *root = btrfs_sb(sb); 1007 int ret; 1008 1009 ret = btrfs_parse_options(root, data); 1010 if (ret) 1011 return -EINVAL; 1012 1013 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1014 return 0; 1015 1016 if (*flags & MS_RDONLY) { 1017 sb->s_flags |= MS_RDONLY; 1018 1019 ret = btrfs_commit_super(root); 1020 WARN_ON(ret); 1021 } else { 1022 if (root->fs_info->fs_devices->rw_devices == 0) 1023 return -EACCES; 1024 1025 if (btrfs_super_log_root(root->fs_info->super_copy) != 0) 1026 return -EINVAL; 1027 1028 ret = btrfs_cleanup_fs_roots(root->fs_info); 1029 WARN_ON(ret); 1030 1031 /* recover relocation */ 1032 ret = btrfs_recover_relocation(root); 1033 WARN_ON(ret); 1034 1035 sb->s_flags &= ~MS_RDONLY; 1036 } 1037 1038 return 0; 1039 } 1040 1041 /* Used to sort the devices by max_avail(descending sort) */ 1042 static int btrfs_cmp_device_free_bytes(const void *dev_info1, 1043 const void *dev_info2) 1044 { 1045 if (((struct btrfs_device_info *)dev_info1)->max_avail > 1046 ((struct btrfs_device_info *)dev_info2)->max_avail) 1047 return -1; 1048 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 1049 ((struct btrfs_device_info *)dev_info2)->max_avail) 1050 return 1; 1051 else 1052 return 0; 1053 } 1054 1055 /* 1056 * sort the devices by max_avail, in which max free extent size of each device 1057 * is stored.(Descending Sort) 1058 */ 1059 static inline void btrfs_descending_sort_devices( 1060 struct btrfs_device_info *devices, 1061 size_t nr_devices) 1062 { 1063 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1064 btrfs_cmp_device_free_bytes, NULL); 1065 } 1066 1067 /* 1068 * The helper to calc the free space on the devices that can be used to store 1069 * file data. 1070 */ 1071 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) 1072 { 1073 struct btrfs_fs_info *fs_info = root->fs_info; 1074 struct btrfs_device_info *devices_info; 1075 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1076 struct btrfs_device *device; 1077 u64 skip_space; 1078 u64 type; 1079 u64 avail_space; 1080 u64 used_space; 1081 u64 min_stripe_size; 1082 int min_stripes = 1; 1083 int i = 0, nr_devices; 1084 int ret; 1085 1086 nr_devices = fs_info->fs_devices->rw_devices; 1087 BUG_ON(!nr_devices); 1088 1089 devices_info = kmalloc(sizeof(*devices_info) * nr_devices, 1090 GFP_NOFS); 1091 if (!devices_info) 1092 return -ENOMEM; 1093 1094 /* calc min stripe number for data space alloction */ 1095 type = btrfs_get_alloc_profile(root, 1); 1096 if (type & BTRFS_BLOCK_GROUP_RAID0) 1097 min_stripes = 2; 1098 else if (type & BTRFS_BLOCK_GROUP_RAID1) 1099 min_stripes = 2; 1100 else if (type & BTRFS_BLOCK_GROUP_RAID10) 1101 min_stripes = 4; 1102 1103 if (type & BTRFS_BLOCK_GROUP_DUP) 1104 min_stripe_size = 2 * BTRFS_STRIPE_LEN; 1105 else 1106 min_stripe_size = BTRFS_STRIPE_LEN; 1107 1108 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { 1109 if (!device->in_fs_metadata) 1110 continue; 1111 1112 avail_space = device->total_bytes - device->bytes_used; 1113 1114 /* align with stripe_len */ 1115 do_div(avail_space, BTRFS_STRIPE_LEN); 1116 avail_space *= BTRFS_STRIPE_LEN; 1117 1118 /* 1119 * In order to avoid overwritting the superblock on the drive, 1120 * btrfs starts at an offset of at least 1MB when doing chunk 1121 * allocation. 1122 */ 1123 skip_space = 1024 * 1024; 1124 1125 /* user can set the offset in fs_info->alloc_start. */ 1126 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <= 1127 device->total_bytes) 1128 skip_space = max(fs_info->alloc_start, skip_space); 1129 1130 /* 1131 * btrfs can not use the free space in [0, skip_space - 1], 1132 * we must subtract it from the total. In order to implement 1133 * it, we account the used space in this range first. 1134 */ 1135 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1, 1136 &used_space); 1137 if (ret) { 1138 kfree(devices_info); 1139 return ret; 1140 } 1141 1142 /* calc the free space in [0, skip_space - 1] */ 1143 skip_space -= used_space; 1144 1145 /* 1146 * we can use the free space in [0, skip_space - 1], subtract 1147 * it from the total. 1148 */ 1149 if (avail_space && avail_space >= skip_space) 1150 avail_space -= skip_space; 1151 else 1152 avail_space = 0; 1153 1154 if (avail_space < min_stripe_size) 1155 continue; 1156 1157 devices_info[i].dev = device; 1158 devices_info[i].max_avail = avail_space; 1159 1160 i++; 1161 } 1162 1163 nr_devices = i; 1164 1165 btrfs_descending_sort_devices(devices_info, nr_devices); 1166 1167 i = nr_devices - 1; 1168 avail_space = 0; 1169 while (nr_devices >= min_stripes) { 1170 if (devices_info[i].max_avail >= min_stripe_size) { 1171 int j; 1172 u64 alloc_size; 1173 1174 avail_space += devices_info[i].max_avail * min_stripes; 1175 alloc_size = devices_info[i].max_avail; 1176 for (j = i + 1 - min_stripes; j <= i; j++) 1177 devices_info[j].max_avail -= alloc_size; 1178 } 1179 i--; 1180 nr_devices--; 1181 } 1182 1183 kfree(devices_info); 1184 *free_bytes = avail_space; 1185 return 0; 1186 } 1187 1188 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 1189 { 1190 struct btrfs_root *root = btrfs_sb(dentry->d_sb); 1191 struct btrfs_super_block *disk_super = root->fs_info->super_copy; 1192 struct list_head *head = &root->fs_info->space_info; 1193 struct btrfs_space_info *found; 1194 u64 total_used = 0; 1195 u64 total_free_data = 0; 1196 int bits = dentry->d_sb->s_blocksize_bits; 1197 __be32 *fsid = (__be32 *)root->fs_info->fsid; 1198 int ret; 1199 1200 /* holding chunk_muext to avoid allocating new chunks */ 1201 mutex_lock(&root->fs_info->chunk_mutex); 1202 rcu_read_lock(); 1203 list_for_each_entry_rcu(found, head, list) { 1204 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 1205 total_free_data += found->disk_total - found->disk_used; 1206 total_free_data -= 1207 btrfs_account_ro_block_groups_free_space(found); 1208 } 1209 1210 total_used += found->disk_used; 1211 } 1212 rcu_read_unlock(); 1213 1214 buf->f_namelen = BTRFS_NAME_LEN; 1215 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; 1216 buf->f_bfree = buf->f_blocks - (total_used >> bits); 1217 buf->f_bsize = dentry->d_sb->s_blocksize; 1218 buf->f_type = BTRFS_SUPER_MAGIC; 1219 buf->f_bavail = total_free_data; 1220 ret = btrfs_calc_avail_data_space(root, &total_free_data); 1221 if (ret) { 1222 mutex_unlock(&root->fs_info->chunk_mutex); 1223 return ret; 1224 } 1225 buf->f_bavail += total_free_data; 1226 buf->f_bavail = buf->f_bavail >> bits; 1227 mutex_unlock(&root->fs_info->chunk_mutex); 1228 1229 /* We treat it as constant endianness (it doesn't matter _which_) 1230 because we want the fsid to come out the same whether mounted 1231 on a big-endian or little-endian host */ 1232 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 1233 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 1234 /* Mask in the root object ID too, to disambiguate subvols */ 1235 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; 1236 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; 1237 1238 return 0; 1239 } 1240 1241 static struct file_system_type btrfs_fs_type = { 1242 .owner = THIS_MODULE, 1243 .name = "btrfs", 1244 .mount = btrfs_mount, 1245 .kill_sb = kill_anon_super, 1246 .fs_flags = FS_REQUIRES_DEV, 1247 }; 1248 1249 /* 1250 * used by btrfsctl to scan devices when no FS is mounted 1251 */ 1252 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 1253 unsigned long arg) 1254 { 1255 struct btrfs_ioctl_vol_args *vol; 1256 struct btrfs_fs_devices *fs_devices; 1257 int ret = -ENOTTY; 1258 1259 if (!capable(CAP_SYS_ADMIN)) 1260 return -EPERM; 1261 1262 vol = memdup_user((void __user *)arg, sizeof(*vol)); 1263 if (IS_ERR(vol)) 1264 return PTR_ERR(vol); 1265 1266 switch (cmd) { 1267 case BTRFS_IOC_SCAN_DEV: 1268 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 1269 &btrfs_fs_type, &fs_devices); 1270 break; 1271 } 1272 1273 kfree(vol); 1274 return ret; 1275 } 1276 1277 static int btrfs_freeze(struct super_block *sb) 1278 { 1279 struct btrfs_root *root = btrfs_sb(sb); 1280 mutex_lock(&root->fs_info->transaction_kthread_mutex); 1281 mutex_lock(&root->fs_info->cleaner_mutex); 1282 return 0; 1283 } 1284 1285 static int btrfs_unfreeze(struct super_block *sb) 1286 { 1287 struct btrfs_root *root = btrfs_sb(sb); 1288 mutex_unlock(&root->fs_info->cleaner_mutex); 1289 mutex_unlock(&root->fs_info->transaction_kthread_mutex); 1290 return 0; 1291 } 1292 1293 static const struct super_operations btrfs_super_ops = { 1294 .drop_inode = btrfs_drop_inode, 1295 .evict_inode = btrfs_evict_inode, 1296 .put_super = btrfs_put_super, 1297 .sync_fs = btrfs_sync_fs, 1298 .show_options = btrfs_show_options, 1299 .write_inode = btrfs_write_inode, 1300 .dirty_inode = btrfs_dirty_inode, 1301 .alloc_inode = btrfs_alloc_inode, 1302 .destroy_inode = btrfs_destroy_inode, 1303 .statfs = btrfs_statfs, 1304 .remount_fs = btrfs_remount, 1305 .freeze_fs = btrfs_freeze, 1306 .unfreeze_fs = btrfs_unfreeze, 1307 }; 1308 1309 static const struct file_operations btrfs_ctl_fops = { 1310 .unlocked_ioctl = btrfs_control_ioctl, 1311 .compat_ioctl = btrfs_control_ioctl, 1312 .owner = THIS_MODULE, 1313 .llseek = noop_llseek, 1314 }; 1315 1316 static struct miscdevice btrfs_misc = { 1317 .minor = BTRFS_MINOR, 1318 .name = "btrfs-control", 1319 .fops = &btrfs_ctl_fops 1320 }; 1321 1322 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 1323 MODULE_ALIAS("devname:btrfs-control"); 1324 1325 static int btrfs_interface_init(void) 1326 { 1327 return misc_register(&btrfs_misc); 1328 } 1329 1330 static void btrfs_interface_exit(void) 1331 { 1332 if (misc_deregister(&btrfs_misc) < 0) 1333 printk(KERN_INFO "misc_deregister failed for control device"); 1334 } 1335 1336 static int __init init_btrfs_fs(void) 1337 { 1338 int err; 1339 1340 err = btrfs_init_sysfs(); 1341 if (err) 1342 return err; 1343 1344 err = btrfs_init_compress(); 1345 if (err) 1346 goto free_sysfs; 1347 1348 err = btrfs_init_cachep(); 1349 if (err) 1350 goto free_compress; 1351 1352 err = extent_io_init(); 1353 if (err) 1354 goto free_cachep; 1355 1356 err = extent_map_init(); 1357 if (err) 1358 goto free_extent_io; 1359 1360 err = btrfs_delayed_inode_init(); 1361 if (err) 1362 goto free_extent_map; 1363 1364 err = btrfs_interface_init(); 1365 if (err) 1366 goto free_delayed_inode; 1367 1368 err = register_filesystem(&btrfs_fs_type); 1369 if (err) 1370 goto unregister_ioctl; 1371 1372 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); 1373 return 0; 1374 1375 unregister_ioctl: 1376 btrfs_interface_exit(); 1377 free_delayed_inode: 1378 btrfs_delayed_inode_exit(); 1379 free_extent_map: 1380 extent_map_exit(); 1381 free_extent_io: 1382 extent_io_exit(); 1383 free_cachep: 1384 btrfs_destroy_cachep(); 1385 free_compress: 1386 btrfs_exit_compress(); 1387 free_sysfs: 1388 btrfs_exit_sysfs(); 1389 return err; 1390 } 1391 1392 static void __exit exit_btrfs_fs(void) 1393 { 1394 btrfs_destroy_cachep(); 1395 btrfs_delayed_inode_exit(); 1396 extent_map_exit(); 1397 extent_io_exit(); 1398 btrfs_interface_exit(); 1399 unregister_filesystem(&btrfs_fs_type); 1400 btrfs_exit_sysfs(); 1401 btrfs_cleanup_fs_uuids(); 1402 btrfs_exit_compress(); 1403 } 1404 1405 module_init(init_btrfs_fs) 1406 module_exit(exit_btrfs_fs) 1407 1408 MODULE_LICENSE("GPL"); 1409