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, "no_space_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 *subvol_name = match_strdup(&args[0]); 452 break; 453 case Opt_subvolid: 454 intarg = 0; 455 error = match_int(&args[0], &intarg); 456 if (!error) { 457 /* we want the original fs_tree */ 458 if (!intarg) 459 *subvol_objectid = 460 BTRFS_FS_TREE_OBJECTID; 461 else 462 *subvol_objectid = intarg; 463 } 464 break; 465 case Opt_subvolrootid: 466 intarg = 0; 467 error = match_int(&args[0], &intarg); 468 if (!error) { 469 /* we want the original fs_tree */ 470 if (!intarg) 471 *subvol_rootid = 472 BTRFS_FS_TREE_OBJECTID; 473 else 474 *subvol_rootid = intarg; 475 } 476 break; 477 case Opt_device: 478 device_name = match_strdup(&args[0]); 479 if (!device_name) { 480 error = -ENOMEM; 481 goto out; 482 } 483 error = btrfs_scan_one_device(device_name, 484 flags, holder, fs_devices); 485 kfree(device_name); 486 if (error) 487 goto out; 488 break; 489 default: 490 break; 491 } 492 } 493 494 out: 495 kfree(orig); 496 return error; 497 } 498 499 static struct dentry *get_default_root(struct super_block *sb, 500 u64 subvol_objectid) 501 { 502 struct btrfs_root *root = sb->s_fs_info; 503 struct btrfs_root *new_root; 504 struct btrfs_dir_item *di; 505 struct btrfs_path *path; 506 struct btrfs_key location; 507 struct inode *inode; 508 u64 dir_id; 509 int new = 0; 510 511 /* 512 * We have a specific subvol we want to mount, just setup location and 513 * go look up the root. 514 */ 515 if (subvol_objectid) { 516 location.objectid = subvol_objectid; 517 location.type = BTRFS_ROOT_ITEM_KEY; 518 location.offset = (u64)-1; 519 goto find_root; 520 } 521 522 path = btrfs_alloc_path(); 523 if (!path) 524 return ERR_PTR(-ENOMEM); 525 path->leave_spinning = 1; 526 527 /* 528 * Find the "default" dir item which points to the root item that we 529 * will mount by default if we haven't been given a specific subvolume 530 * to mount. 531 */ 532 dir_id = btrfs_super_root_dir(root->fs_info->super_copy); 533 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 534 if (IS_ERR(di)) { 535 btrfs_free_path(path); 536 return ERR_CAST(di); 537 } 538 if (!di) { 539 /* 540 * Ok the default dir item isn't there. This is weird since 541 * it's always been there, but don't freak out, just try and 542 * mount to root most subvolume. 543 */ 544 btrfs_free_path(path); 545 dir_id = BTRFS_FIRST_FREE_OBJECTID; 546 new_root = root->fs_info->fs_root; 547 goto setup_root; 548 } 549 550 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 551 btrfs_free_path(path); 552 553 find_root: 554 new_root = btrfs_read_fs_root_no_name(root->fs_info, &location); 555 if (IS_ERR(new_root)) 556 return ERR_CAST(new_root); 557 558 if (btrfs_root_refs(&new_root->root_item) == 0) 559 return ERR_PTR(-ENOENT); 560 561 dir_id = btrfs_root_dirid(&new_root->root_item); 562 setup_root: 563 location.objectid = dir_id; 564 location.type = BTRFS_INODE_ITEM_KEY; 565 location.offset = 0; 566 567 inode = btrfs_iget(sb, &location, new_root, &new); 568 if (IS_ERR(inode)) 569 return ERR_CAST(inode); 570 571 /* 572 * If we're just mounting the root most subvol put the inode and return 573 * a reference to the dentry. We will have already gotten a reference 574 * to the inode in btrfs_fill_super so we're good to go. 575 */ 576 if (!new && sb->s_root->d_inode == inode) { 577 iput(inode); 578 return dget(sb->s_root); 579 } 580 581 return d_obtain_alias(inode); 582 } 583 584 static int btrfs_fill_super(struct super_block *sb, 585 struct btrfs_fs_devices *fs_devices, 586 void *data, int silent) 587 { 588 struct inode *inode; 589 struct dentry *root_dentry; 590 struct btrfs_root *tree_root; 591 struct btrfs_key key; 592 int err; 593 594 sb->s_maxbytes = MAX_LFS_FILESIZE; 595 sb->s_magic = BTRFS_SUPER_MAGIC; 596 sb->s_op = &btrfs_super_ops; 597 sb->s_d_op = &btrfs_dentry_operations; 598 sb->s_export_op = &btrfs_export_ops; 599 sb->s_xattr = btrfs_xattr_handlers; 600 sb->s_time_gran = 1; 601 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 602 sb->s_flags |= MS_POSIXACL; 603 #endif 604 605 tree_root = open_ctree(sb, fs_devices, (char *)data); 606 607 if (IS_ERR(tree_root)) { 608 printk("btrfs: open_ctree failed\n"); 609 return PTR_ERR(tree_root); 610 } 611 sb->s_fs_info = tree_root; 612 613 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 614 key.type = BTRFS_INODE_ITEM_KEY; 615 key.offset = 0; 616 inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL); 617 if (IS_ERR(inode)) { 618 err = PTR_ERR(inode); 619 goto fail_close; 620 } 621 622 root_dentry = d_alloc_root(inode); 623 if (!root_dentry) { 624 iput(inode); 625 err = -ENOMEM; 626 goto fail_close; 627 } 628 629 sb->s_root = root_dentry; 630 631 save_mount_options(sb, data); 632 cleancache_init_fs(sb); 633 return 0; 634 635 fail_close: 636 close_ctree(tree_root); 637 return err; 638 } 639 640 int btrfs_sync_fs(struct super_block *sb, int wait) 641 { 642 struct btrfs_trans_handle *trans; 643 struct btrfs_root *root = btrfs_sb(sb); 644 int ret; 645 646 trace_btrfs_sync_fs(wait); 647 648 if (!wait) { 649 filemap_flush(root->fs_info->btree_inode->i_mapping); 650 return 0; 651 } 652 653 btrfs_start_delalloc_inodes(root, 0); 654 btrfs_wait_ordered_extents(root, 0, 0); 655 656 trans = btrfs_start_transaction(root, 0); 657 if (IS_ERR(trans)) 658 return PTR_ERR(trans); 659 ret = btrfs_commit_transaction(trans, root); 660 return ret; 661 } 662 663 static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs) 664 { 665 struct btrfs_root *root = btrfs_sb(vfs->mnt_sb); 666 struct btrfs_fs_info *info = root->fs_info; 667 char *compress_type; 668 669 if (btrfs_test_opt(root, DEGRADED)) 670 seq_puts(seq, ",degraded"); 671 if (btrfs_test_opt(root, NODATASUM)) 672 seq_puts(seq, ",nodatasum"); 673 if (btrfs_test_opt(root, NODATACOW)) 674 seq_puts(seq, ",nodatacow"); 675 if (btrfs_test_opt(root, NOBARRIER)) 676 seq_puts(seq, ",nobarrier"); 677 if (info->max_inline != 8192 * 1024) 678 seq_printf(seq, ",max_inline=%llu", 679 (unsigned long long)info->max_inline); 680 if (info->alloc_start != 0) 681 seq_printf(seq, ",alloc_start=%llu", 682 (unsigned long long)info->alloc_start); 683 if (info->thread_pool_size != min_t(unsigned long, 684 num_online_cpus() + 2, 8)) 685 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 686 if (btrfs_test_opt(root, COMPRESS)) { 687 if (info->compress_type == BTRFS_COMPRESS_ZLIB) 688 compress_type = "zlib"; 689 else 690 compress_type = "lzo"; 691 if (btrfs_test_opt(root, FORCE_COMPRESS)) 692 seq_printf(seq, ",compress-force=%s", compress_type); 693 else 694 seq_printf(seq, ",compress=%s", compress_type); 695 } 696 if (btrfs_test_opt(root, NOSSD)) 697 seq_puts(seq, ",nossd"); 698 if (btrfs_test_opt(root, SSD_SPREAD)) 699 seq_puts(seq, ",ssd_spread"); 700 else if (btrfs_test_opt(root, SSD)) 701 seq_puts(seq, ",ssd"); 702 if (btrfs_test_opt(root, NOTREELOG)) 703 seq_puts(seq, ",notreelog"); 704 if (btrfs_test_opt(root, FLUSHONCOMMIT)) 705 seq_puts(seq, ",flushoncommit"); 706 if (btrfs_test_opt(root, DISCARD)) 707 seq_puts(seq, ",discard"); 708 if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) 709 seq_puts(seq, ",noacl"); 710 if (btrfs_test_opt(root, SPACE_CACHE)) 711 seq_puts(seq, ",space_cache"); 712 else 713 seq_puts(seq, ",no_space_cache"); 714 if (btrfs_test_opt(root, CLEAR_CACHE)) 715 seq_puts(seq, ",clear_cache"); 716 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 717 seq_puts(seq, ",user_subvol_rm_allowed"); 718 if (btrfs_test_opt(root, ENOSPC_DEBUG)) 719 seq_puts(seq, ",enospc_debug"); 720 if (btrfs_test_opt(root, AUTO_DEFRAG)) 721 seq_puts(seq, ",autodefrag"); 722 if (btrfs_test_opt(root, INODE_MAP_CACHE)) 723 seq_puts(seq, ",inode_cache"); 724 return 0; 725 } 726 727 static int btrfs_test_super(struct super_block *s, void *data) 728 { 729 struct btrfs_root *test_root = data; 730 struct btrfs_root *root = btrfs_sb(s); 731 732 /* 733 * If this super block is going away, return false as it 734 * can't match as an existing super block. 735 */ 736 if (!atomic_read(&s->s_active)) 737 return 0; 738 return root->fs_info->fs_devices == test_root->fs_info->fs_devices; 739 } 740 741 static int btrfs_set_super(struct super_block *s, void *data) 742 { 743 s->s_fs_info = data; 744 745 return set_anon_super(s, data); 746 } 747 748 /* 749 * subvolumes are identified by ino 256 750 */ 751 static inline int is_subvolume_inode(struct inode *inode) 752 { 753 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 754 return 1; 755 return 0; 756 } 757 758 /* 759 * This will strip out the subvol=%s argument for an argument string and add 760 * subvolid=0 to make sure we get the actual tree root for path walking to the 761 * subvol we want. 762 */ 763 static char *setup_root_args(char *args) 764 { 765 unsigned copied = 0; 766 unsigned len = strlen(args) + 2; 767 char *pos; 768 char *ret; 769 770 /* 771 * We need the same args as before, but minus 772 * 773 * subvol=a 774 * 775 * and add 776 * 777 * subvolid=0 778 * 779 * which is a difference of 2 characters, so we allocate strlen(args) + 780 * 2 characters. 781 */ 782 ret = kzalloc(len * sizeof(char), GFP_NOFS); 783 if (!ret) 784 return NULL; 785 pos = strstr(args, "subvol="); 786 787 /* This shouldn't happen, but just in case.. */ 788 if (!pos) { 789 kfree(ret); 790 return NULL; 791 } 792 793 /* 794 * The subvol=<> arg is not at the front of the string, copy everybody 795 * up to that into ret. 796 */ 797 if (pos != args) { 798 *pos = '\0'; 799 strcpy(ret, args); 800 copied += strlen(args); 801 pos++; 802 } 803 804 strncpy(ret + copied, "subvolid=0", len - copied); 805 806 /* Length of subvolid=0 */ 807 copied += 10; 808 809 /* 810 * If there is no , after the subvol= option then we know there's no 811 * other options and we can just return. 812 */ 813 pos = strchr(pos, ','); 814 if (!pos) 815 return ret; 816 817 /* Copy the rest of the arguments into our buffer */ 818 strncpy(ret + copied, pos, len - copied); 819 copied += strlen(pos); 820 821 return ret; 822 } 823 824 static struct dentry *mount_subvol(const char *subvol_name, int flags, 825 const char *device_name, char *data) 826 { 827 struct super_block *s; 828 struct dentry *root; 829 struct vfsmount *mnt; 830 struct mnt_namespace *ns_private; 831 char *newargs; 832 struct path path; 833 int error; 834 835 newargs = setup_root_args(data); 836 if (!newargs) 837 return ERR_PTR(-ENOMEM); 838 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, 839 newargs); 840 kfree(newargs); 841 if (IS_ERR(mnt)) 842 return ERR_CAST(mnt); 843 844 ns_private = create_mnt_ns(mnt); 845 if (IS_ERR(ns_private)) { 846 mntput(mnt); 847 return ERR_CAST(ns_private); 848 } 849 850 /* 851 * This will trigger the automount of the subvol so we can just 852 * drop the mnt we have here and return the dentry that we 853 * found. 854 */ 855 error = vfs_path_lookup(mnt->mnt_root, mnt, subvol_name, 856 LOOKUP_FOLLOW, &path); 857 put_mnt_ns(ns_private); 858 if (error) 859 return ERR_PTR(error); 860 861 if (!is_subvolume_inode(path.dentry->d_inode)) { 862 path_put(&path); 863 mntput(mnt); 864 error = -EINVAL; 865 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n", 866 subvol_name); 867 return ERR_PTR(-EINVAL); 868 } 869 870 /* Get a ref to the sb and the dentry we found and return it */ 871 s = path.mnt->mnt_sb; 872 atomic_inc(&s->s_active); 873 root = dget(path.dentry); 874 path_put(&path); 875 down_write(&s->s_umount); 876 877 return root; 878 } 879 880 /* 881 * Find a superblock for the given device / mount point. 882 * 883 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 884 * for multiple device setup. Make sure to keep it in sync. 885 */ 886 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 887 const char *device_name, void *data) 888 { 889 struct block_device *bdev = NULL; 890 struct super_block *s; 891 struct dentry *root; 892 struct btrfs_fs_devices *fs_devices = NULL; 893 struct btrfs_root *tree_root = 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 return ERR_PTR(error); 909 910 if (subvol_name) { 911 root = mount_subvol(subvol_name, flags, device_name, data); 912 kfree(subvol_name); 913 return root; 914 } 915 916 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); 917 if (error) 918 return ERR_PTR(error); 919 920 error = btrfs_open_devices(fs_devices, mode, fs_type); 921 if (error) 922 return ERR_PTR(error); 923 924 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 925 error = -EACCES; 926 goto error_close_devices; 927 } 928 929 /* 930 * Setup a dummy root and fs_info for test/set super. This is because 931 * we don't actually fill this stuff out until open_ctree, but we need 932 * it for searching for existing supers, so this lets us do that and 933 * then open_ctree will properly initialize everything later. 934 */ 935 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); 936 tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS); 937 if (!fs_info || !tree_root) { 938 error = -ENOMEM; 939 goto error_close_devices; 940 } 941 fs_info->tree_root = tree_root; 942 fs_info->fs_devices = fs_devices; 943 tree_root->fs_info = fs_info; 944 945 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 946 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 947 if (!fs_info->super_copy || !fs_info->super_for_commit) { 948 error = -ENOMEM; 949 goto error_close_devices; 950 } 951 952 bdev = fs_devices->latest_bdev; 953 s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root); 954 if (IS_ERR(s)) { 955 error = PTR_ERR(s); 956 goto error_close_devices; 957 } 958 959 if (s->s_root) { 960 if ((flags ^ s->s_flags) & MS_RDONLY) { 961 deactivate_locked_super(s); 962 return ERR_PTR(-EBUSY); 963 } 964 965 btrfs_close_devices(fs_devices); 966 free_fs_info(fs_info); 967 kfree(tree_root); 968 } else { 969 char b[BDEVNAME_SIZE]; 970 971 s->s_flags = flags | MS_NOSEC; 972 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); 973 btrfs_sb(s)->fs_info->bdev_holder = fs_type; 974 error = btrfs_fill_super(s, fs_devices, data, 975 flags & MS_SILENT ? 1 : 0); 976 if (error) { 977 deactivate_locked_super(s); 978 return ERR_PTR(error); 979 } 980 981 s->s_flags |= MS_ACTIVE; 982 } 983 984 root = get_default_root(s, subvol_objectid); 985 if (IS_ERR(root)) { 986 deactivate_locked_super(s); 987 return root; 988 } 989 990 return root; 991 992 error_close_devices: 993 btrfs_close_devices(fs_devices); 994 free_fs_info(fs_info); 995 kfree(tree_root); 996 return ERR_PTR(error); 997 } 998 999 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1000 { 1001 struct btrfs_root *root = btrfs_sb(sb); 1002 int ret; 1003 1004 ret = btrfs_parse_options(root, data); 1005 if (ret) 1006 return -EINVAL; 1007 1008 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1009 return 0; 1010 1011 if (*flags & MS_RDONLY) { 1012 sb->s_flags |= MS_RDONLY; 1013 1014 ret = btrfs_commit_super(root); 1015 WARN_ON(ret); 1016 } else { 1017 if (root->fs_info->fs_devices->rw_devices == 0) 1018 return -EACCES; 1019 1020 if (btrfs_super_log_root(root->fs_info->super_copy) != 0) 1021 return -EINVAL; 1022 1023 ret = btrfs_cleanup_fs_roots(root->fs_info); 1024 WARN_ON(ret); 1025 1026 /* recover relocation */ 1027 ret = btrfs_recover_relocation(root); 1028 WARN_ON(ret); 1029 1030 sb->s_flags &= ~MS_RDONLY; 1031 } 1032 1033 return 0; 1034 } 1035 1036 /* Used to sort the devices by max_avail(descending sort) */ 1037 static int btrfs_cmp_device_free_bytes(const void *dev_info1, 1038 const void *dev_info2) 1039 { 1040 if (((struct btrfs_device_info *)dev_info1)->max_avail > 1041 ((struct btrfs_device_info *)dev_info2)->max_avail) 1042 return -1; 1043 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 1044 ((struct btrfs_device_info *)dev_info2)->max_avail) 1045 return 1; 1046 else 1047 return 0; 1048 } 1049 1050 /* 1051 * sort the devices by max_avail, in which max free extent size of each device 1052 * is stored.(Descending Sort) 1053 */ 1054 static inline void btrfs_descending_sort_devices( 1055 struct btrfs_device_info *devices, 1056 size_t nr_devices) 1057 { 1058 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1059 btrfs_cmp_device_free_bytes, NULL); 1060 } 1061 1062 /* 1063 * The helper to calc the free space on the devices that can be used to store 1064 * file data. 1065 */ 1066 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) 1067 { 1068 struct btrfs_fs_info *fs_info = root->fs_info; 1069 struct btrfs_device_info *devices_info; 1070 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1071 struct btrfs_device *device; 1072 u64 skip_space; 1073 u64 type; 1074 u64 avail_space; 1075 u64 used_space; 1076 u64 min_stripe_size; 1077 int min_stripes = 1; 1078 int i = 0, nr_devices; 1079 int ret; 1080 1081 nr_devices = fs_info->fs_devices->rw_devices; 1082 BUG_ON(!nr_devices); 1083 1084 devices_info = kmalloc(sizeof(*devices_info) * nr_devices, 1085 GFP_NOFS); 1086 if (!devices_info) 1087 return -ENOMEM; 1088 1089 /* calc min stripe number for data space alloction */ 1090 type = btrfs_get_alloc_profile(root, 1); 1091 if (type & BTRFS_BLOCK_GROUP_RAID0) 1092 min_stripes = 2; 1093 else if (type & BTRFS_BLOCK_GROUP_RAID1) 1094 min_stripes = 2; 1095 else if (type & BTRFS_BLOCK_GROUP_RAID10) 1096 min_stripes = 4; 1097 1098 if (type & BTRFS_BLOCK_GROUP_DUP) 1099 min_stripe_size = 2 * BTRFS_STRIPE_LEN; 1100 else 1101 min_stripe_size = BTRFS_STRIPE_LEN; 1102 1103 list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { 1104 if (!device->in_fs_metadata) 1105 continue; 1106 1107 avail_space = device->total_bytes - device->bytes_used; 1108 1109 /* align with stripe_len */ 1110 do_div(avail_space, BTRFS_STRIPE_LEN); 1111 avail_space *= BTRFS_STRIPE_LEN; 1112 1113 /* 1114 * In order to avoid overwritting the superblock on the drive, 1115 * btrfs starts at an offset of at least 1MB when doing chunk 1116 * allocation. 1117 */ 1118 skip_space = 1024 * 1024; 1119 1120 /* user can set the offset in fs_info->alloc_start. */ 1121 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <= 1122 device->total_bytes) 1123 skip_space = max(fs_info->alloc_start, skip_space); 1124 1125 /* 1126 * btrfs can not use the free space in [0, skip_space - 1], 1127 * we must subtract it from the total. In order to implement 1128 * it, we account the used space in this range first. 1129 */ 1130 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1, 1131 &used_space); 1132 if (ret) { 1133 kfree(devices_info); 1134 return ret; 1135 } 1136 1137 /* calc the free space in [0, skip_space - 1] */ 1138 skip_space -= used_space; 1139 1140 /* 1141 * we can use the free space in [0, skip_space - 1], subtract 1142 * it from the total. 1143 */ 1144 if (avail_space && avail_space >= skip_space) 1145 avail_space -= skip_space; 1146 else 1147 avail_space = 0; 1148 1149 if (avail_space < min_stripe_size) 1150 continue; 1151 1152 devices_info[i].dev = device; 1153 devices_info[i].max_avail = avail_space; 1154 1155 i++; 1156 } 1157 1158 nr_devices = i; 1159 1160 btrfs_descending_sort_devices(devices_info, nr_devices); 1161 1162 i = nr_devices - 1; 1163 avail_space = 0; 1164 while (nr_devices >= min_stripes) { 1165 if (devices_info[i].max_avail >= min_stripe_size) { 1166 int j; 1167 u64 alloc_size; 1168 1169 avail_space += devices_info[i].max_avail * min_stripes; 1170 alloc_size = devices_info[i].max_avail; 1171 for (j = i + 1 - min_stripes; j <= i; j++) 1172 devices_info[j].max_avail -= alloc_size; 1173 } 1174 i--; 1175 nr_devices--; 1176 } 1177 1178 kfree(devices_info); 1179 *free_bytes = avail_space; 1180 return 0; 1181 } 1182 1183 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 1184 { 1185 struct btrfs_root *root = btrfs_sb(dentry->d_sb); 1186 struct btrfs_super_block *disk_super = root->fs_info->super_copy; 1187 struct list_head *head = &root->fs_info->space_info; 1188 struct btrfs_space_info *found; 1189 u64 total_used = 0; 1190 u64 total_free_data = 0; 1191 int bits = dentry->d_sb->s_blocksize_bits; 1192 __be32 *fsid = (__be32 *)root->fs_info->fsid; 1193 int ret; 1194 1195 /* holding chunk_muext to avoid allocating new chunks */ 1196 mutex_lock(&root->fs_info->chunk_mutex); 1197 rcu_read_lock(); 1198 list_for_each_entry_rcu(found, head, list) { 1199 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 1200 total_free_data += found->disk_total - found->disk_used; 1201 total_free_data -= 1202 btrfs_account_ro_block_groups_free_space(found); 1203 } 1204 1205 total_used += found->disk_used; 1206 } 1207 rcu_read_unlock(); 1208 1209 buf->f_namelen = BTRFS_NAME_LEN; 1210 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; 1211 buf->f_bfree = buf->f_blocks - (total_used >> bits); 1212 buf->f_bsize = dentry->d_sb->s_blocksize; 1213 buf->f_type = BTRFS_SUPER_MAGIC; 1214 buf->f_bavail = total_free_data; 1215 ret = btrfs_calc_avail_data_space(root, &total_free_data); 1216 if (ret) { 1217 mutex_unlock(&root->fs_info->chunk_mutex); 1218 return ret; 1219 } 1220 buf->f_bavail += total_free_data; 1221 buf->f_bavail = buf->f_bavail >> bits; 1222 mutex_unlock(&root->fs_info->chunk_mutex); 1223 1224 /* We treat it as constant endianness (it doesn't matter _which_) 1225 because we want the fsid to come out the same whether mounted 1226 on a big-endian or little-endian host */ 1227 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 1228 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 1229 /* Mask in the root object ID too, to disambiguate subvols */ 1230 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; 1231 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; 1232 1233 return 0; 1234 } 1235 1236 static struct file_system_type btrfs_fs_type = { 1237 .owner = THIS_MODULE, 1238 .name = "btrfs", 1239 .mount = btrfs_mount, 1240 .kill_sb = kill_anon_super, 1241 .fs_flags = FS_REQUIRES_DEV, 1242 }; 1243 1244 /* 1245 * used by btrfsctl to scan devices when no FS is mounted 1246 */ 1247 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 1248 unsigned long arg) 1249 { 1250 struct btrfs_ioctl_vol_args *vol; 1251 struct btrfs_fs_devices *fs_devices; 1252 int ret = -ENOTTY; 1253 1254 if (!capable(CAP_SYS_ADMIN)) 1255 return -EPERM; 1256 1257 vol = memdup_user((void __user *)arg, sizeof(*vol)); 1258 if (IS_ERR(vol)) 1259 return PTR_ERR(vol); 1260 1261 switch (cmd) { 1262 case BTRFS_IOC_SCAN_DEV: 1263 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 1264 &btrfs_fs_type, &fs_devices); 1265 break; 1266 } 1267 1268 kfree(vol); 1269 return ret; 1270 } 1271 1272 static int btrfs_freeze(struct super_block *sb) 1273 { 1274 struct btrfs_root *root = btrfs_sb(sb); 1275 mutex_lock(&root->fs_info->transaction_kthread_mutex); 1276 mutex_lock(&root->fs_info->cleaner_mutex); 1277 return 0; 1278 } 1279 1280 static int btrfs_unfreeze(struct super_block *sb) 1281 { 1282 struct btrfs_root *root = btrfs_sb(sb); 1283 mutex_unlock(&root->fs_info->cleaner_mutex); 1284 mutex_unlock(&root->fs_info->transaction_kthread_mutex); 1285 return 0; 1286 } 1287 1288 static const struct super_operations btrfs_super_ops = { 1289 .drop_inode = btrfs_drop_inode, 1290 .evict_inode = btrfs_evict_inode, 1291 .put_super = btrfs_put_super, 1292 .sync_fs = btrfs_sync_fs, 1293 .show_options = btrfs_show_options, 1294 .write_inode = btrfs_write_inode, 1295 .dirty_inode = btrfs_dirty_inode, 1296 .alloc_inode = btrfs_alloc_inode, 1297 .destroy_inode = btrfs_destroy_inode, 1298 .statfs = btrfs_statfs, 1299 .remount_fs = btrfs_remount, 1300 .freeze_fs = btrfs_freeze, 1301 .unfreeze_fs = btrfs_unfreeze, 1302 }; 1303 1304 static const struct file_operations btrfs_ctl_fops = { 1305 .unlocked_ioctl = btrfs_control_ioctl, 1306 .compat_ioctl = btrfs_control_ioctl, 1307 .owner = THIS_MODULE, 1308 .llseek = noop_llseek, 1309 }; 1310 1311 static struct miscdevice btrfs_misc = { 1312 .minor = BTRFS_MINOR, 1313 .name = "btrfs-control", 1314 .fops = &btrfs_ctl_fops 1315 }; 1316 1317 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 1318 MODULE_ALIAS("devname:btrfs-control"); 1319 1320 static int btrfs_interface_init(void) 1321 { 1322 return misc_register(&btrfs_misc); 1323 } 1324 1325 static void btrfs_interface_exit(void) 1326 { 1327 if (misc_deregister(&btrfs_misc) < 0) 1328 printk(KERN_INFO "misc_deregister failed for control device"); 1329 } 1330 1331 static int __init init_btrfs_fs(void) 1332 { 1333 int err; 1334 1335 err = btrfs_init_sysfs(); 1336 if (err) 1337 return err; 1338 1339 err = btrfs_init_compress(); 1340 if (err) 1341 goto free_sysfs; 1342 1343 err = btrfs_init_cachep(); 1344 if (err) 1345 goto free_compress; 1346 1347 err = extent_io_init(); 1348 if (err) 1349 goto free_cachep; 1350 1351 err = extent_map_init(); 1352 if (err) 1353 goto free_extent_io; 1354 1355 err = btrfs_delayed_inode_init(); 1356 if (err) 1357 goto free_extent_map; 1358 1359 err = btrfs_interface_init(); 1360 if (err) 1361 goto free_delayed_inode; 1362 1363 err = register_filesystem(&btrfs_fs_type); 1364 if (err) 1365 goto unregister_ioctl; 1366 1367 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); 1368 return 0; 1369 1370 unregister_ioctl: 1371 btrfs_interface_exit(); 1372 free_delayed_inode: 1373 btrfs_delayed_inode_exit(); 1374 free_extent_map: 1375 extent_map_exit(); 1376 free_extent_io: 1377 extent_io_exit(); 1378 free_cachep: 1379 btrfs_destroy_cachep(); 1380 free_compress: 1381 btrfs_exit_compress(); 1382 free_sysfs: 1383 btrfs_exit_sysfs(); 1384 return err; 1385 } 1386 1387 static void __exit exit_btrfs_fs(void) 1388 { 1389 btrfs_destroy_cachep(); 1390 btrfs_delayed_inode_exit(); 1391 extent_map_exit(); 1392 extent_io_exit(); 1393 btrfs_interface_exit(); 1394 unregister_filesystem(&btrfs_fs_type); 1395 btrfs_exit_sysfs(); 1396 btrfs_cleanup_fs_uuids(); 1397 btrfs_exit_compress(); 1398 } 1399 1400 module_init(init_btrfs_fs) 1401 module_exit(exit_btrfs_fs) 1402 1403 MODULE_LICENSE("GPL"); 1404