1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2007 Oracle. All rights reserved. 4 */ 5 6 #include <linux/blkdev.h> 7 #include <linux/module.h> 8 #include <linux/fs.h> 9 #include <linux/pagemap.h> 10 #include <linux/highmem.h> 11 #include <linux/time.h> 12 #include <linux/init.h> 13 #include <linux/seq_file.h> 14 #include <linux/string.h> 15 #include <linux/backing-dev.h> 16 #include <linux/mount.h> 17 #include <linux/writeback.h> 18 #include <linux/statfs.h> 19 #include <linux/compat.h> 20 #include <linux/parser.h> 21 #include <linux/ctype.h> 22 #include <linux/namei.h> 23 #include <linux/miscdevice.h> 24 #include <linux/magic.h> 25 #include <linux/slab.h> 26 #include <linux/ratelimit.h> 27 #include <linux/crc32c.h> 28 #include <linux/btrfs.h> 29 #include "messages.h" 30 #include "delayed-inode.h" 31 #include "ctree.h" 32 #include "disk-io.h" 33 #include "transaction.h" 34 #include "btrfs_inode.h" 35 #include "print-tree.h" 36 #include "props.h" 37 #include "xattr.h" 38 #include "bio.h" 39 #include "export.h" 40 #include "compression.h" 41 #include "rcu-string.h" 42 #include "dev-replace.h" 43 #include "free-space-cache.h" 44 #include "backref.h" 45 #include "space-info.h" 46 #include "sysfs.h" 47 #include "zoned.h" 48 #include "tests/btrfs-tests.h" 49 #include "block-group.h" 50 #include "discard.h" 51 #include "qgroup.h" 52 #include "raid56.h" 53 #include "fs.h" 54 #include "accessors.h" 55 #include "defrag.h" 56 #include "dir-item.h" 57 #include "ioctl.h" 58 #include "scrub.h" 59 #include "verity.h" 60 #include "super.h" 61 #include "extent-tree.h" 62 #define CREATE_TRACE_POINTS 63 #include <trace/events/btrfs.h> 64 65 static const struct super_operations btrfs_super_ops; 66 67 /* 68 * Types for mounting the default subvolume and a subvolume explicitly 69 * requested by subvol=/path. That way the callchain is straightforward and we 70 * don't have to play tricks with the mount options and recursive calls to 71 * btrfs_mount. 72 * 73 * The new btrfs_root_fs_type also servers as a tag for the bdev_holder. 74 */ 75 static struct file_system_type btrfs_fs_type; 76 static struct file_system_type btrfs_root_fs_type; 77 78 static int btrfs_remount(struct super_block *sb, int *flags, char *data); 79 80 static void btrfs_put_super(struct super_block *sb) 81 { 82 close_ctree(btrfs_sb(sb)); 83 } 84 85 enum { 86 Opt_acl, Opt_noacl, 87 Opt_clear_cache, 88 Opt_commit_interval, 89 Opt_compress, 90 Opt_compress_force, 91 Opt_compress_force_type, 92 Opt_compress_type, 93 Opt_degraded, 94 Opt_device, 95 Opt_fatal_errors, 96 Opt_flushoncommit, Opt_noflushoncommit, 97 Opt_max_inline, 98 Opt_barrier, Opt_nobarrier, 99 Opt_datacow, Opt_nodatacow, 100 Opt_datasum, Opt_nodatasum, 101 Opt_defrag, Opt_nodefrag, 102 Opt_discard, Opt_nodiscard, 103 Opt_discard_mode, 104 Opt_norecovery, 105 Opt_ratio, 106 Opt_rescan_uuid_tree, 107 Opt_skip_balance, 108 Opt_space_cache, Opt_no_space_cache, 109 Opt_space_cache_version, 110 Opt_ssd, Opt_nossd, 111 Opt_ssd_spread, Opt_nossd_spread, 112 Opt_subvol, 113 Opt_subvol_empty, 114 Opt_subvolid, 115 Opt_thread_pool, 116 Opt_treelog, Opt_notreelog, 117 Opt_user_subvol_rm_allowed, 118 119 /* Rescue options */ 120 Opt_rescue, 121 Opt_usebackuproot, 122 Opt_nologreplay, 123 Opt_ignorebadroots, 124 Opt_ignoredatacsums, 125 Opt_rescue_all, 126 127 /* Deprecated options */ 128 Opt_recovery, 129 Opt_inode_cache, Opt_noinode_cache, 130 131 /* Debugging options */ 132 Opt_check_integrity, 133 Opt_check_integrity_including_extent_data, 134 Opt_check_integrity_print_mask, 135 Opt_enospc_debug, Opt_noenospc_debug, 136 #ifdef CONFIG_BTRFS_DEBUG 137 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all, 138 #endif 139 #ifdef CONFIG_BTRFS_FS_REF_VERIFY 140 Opt_ref_verify, 141 #endif 142 Opt_err, 143 }; 144 145 static const match_table_t tokens = { 146 {Opt_acl, "acl"}, 147 {Opt_noacl, "noacl"}, 148 {Opt_clear_cache, "clear_cache"}, 149 {Opt_commit_interval, "commit=%u"}, 150 {Opt_compress, "compress"}, 151 {Opt_compress_type, "compress=%s"}, 152 {Opt_compress_force, "compress-force"}, 153 {Opt_compress_force_type, "compress-force=%s"}, 154 {Opt_degraded, "degraded"}, 155 {Opt_device, "device=%s"}, 156 {Opt_fatal_errors, "fatal_errors=%s"}, 157 {Opt_flushoncommit, "flushoncommit"}, 158 {Opt_noflushoncommit, "noflushoncommit"}, 159 {Opt_inode_cache, "inode_cache"}, 160 {Opt_noinode_cache, "noinode_cache"}, 161 {Opt_max_inline, "max_inline=%s"}, 162 {Opt_barrier, "barrier"}, 163 {Opt_nobarrier, "nobarrier"}, 164 {Opt_datacow, "datacow"}, 165 {Opt_nodatacow, "nodatacow"}, 166 {Opt_datasum, "datasum"}, 167 {Opt_nodatasum, "nodatasum"}, 168 {Opt_defrag, "autodefrag"}, 169 {Opt_nodefrag, "noautodefrag"}, 170 {Opt_discard, "discard"}, 171 {Opt_discard_mode, "discard=%s"}, 172 {Opt_nodiscard, "nodiscard"}, 173 {Opt_norecovery, "norecovery"}, 174 {Opt_ratio, "metadata_ratio=%u"}, 175 {Opt_rescan_uuid_tree, "rescan_uuid_tree"}, 176 {Opt_skip_balance, "skip_balance"}, 177 {Opt_space_cache, "space_cache"}, 178 {Opt_no_space_cache, "nospace_cache"}, 179 {Opt_space_cache_version, "space_cache=%s"}, 180 {Opt_ssd, "ssd"}, 181 {Opt_nossd, "nossd"}, 182 {Opt_ssd_spread, "ssd_spread"}, 183 {Opt_nossd_spread, "nossd_spread"}, 184 {Opt_subvol, "subvol=%s"}, 185 {Opt_subvol_empty, "subvol="}, 186 {Opt_subvolid, "subvolid=%s"}, 187 {Opt_thread_pool, "thread_pool=%u"}, 188 {Opt_treelog, "treelog"}, 189 {Opt_notreelog, "notreelog"}, 190 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, 191 192 /* Rescue options */ 193 {Opt_rescue, "rescue=%s"}, 194 /* Deprecated, with alias rescue=nologreplay */ 195 {Opt_nologreplay, "nologreplay"}, 196 /* Deprecated, with alias rescue=usebackuproot */ 197 {Opt_usebackuproot, "usebackuproot"}, 198 199 /* Deprecated options */ 200 {Opt_recovery, "recovery"}, 201 202 /* Debugging options */ 203 {Opt_check_integrity, "check_int"}, 204 {Opt_check_integrity_including_extent_data, "check_int_data"}, 205 {Opt_check_integrity_print_mask, "check_int_print_mask=%u"}, 206 {Opt_enospc_debug, "enospc_debug"}, 207 {Opt_noenospc_debug, "noenospc_debug"}, 208 #ifdef CONFIG_BTRFS_DEBUG 209 {Opt_fragment_data, "fragment=data"}, 210 {Opt_fragment_metadata, "fragment=metadata"}, 211 {Opt_fragment_all, "fragment=all"}, 212 #endif 213 #ifdef CONFIG_BTRFS_FS_REF_VERIFY 214 {Opt_ref_verify, "ref_verify"}, 215 #endif 216 {Opt_err, NULL}, 217 }; 218 219 static const match_table_t rescue_tokens = { 220 {Opt_usebackuproot, "usebackuproot"}, 221 {Opt_nologreplay, "nologreplay"}, 222 {Opt_ignorebadroots, "ignorebadroots"}, 223 {Opt_ignorebadroots, "ibadroots"}, 224 {Opt_ignoredatacsums, "ignoredatacsums"}, 225 {Opt_ignoredatacsums, "idatacsums"}, 226 {Opt_rescue_all, "all"}, 227 {Opt_err, NULL}, 228 }; 229 230 static bool check_ro_option(struct btrfs_fs_info *fs_info, unsigned long opt, 231 const char *opt_name) 232 { 233 if (fs_info->mount_opt & opt) { 234 btrfs_err(fs_info, "%s must be used with ro mount option", 235 opt_name); 236 return true; 237 } 238 return false; 239 } 240 241 static int parse_rescue_options(struct btrfs_fs_info *info, const char *options) 242 { 243 char *opts; 244 char *orig; 245 char *p; 246 substring_t args[MAX_OPT_ARGS]; 247 int ret = 0; 248 249 opts = kstrdup(options, GFP_KERNEL); 250 if (!opts) 251 return -ENOMEM; 252 orig = opts; 253 254 while ((p = strsep(&opts, ":")) != NULL) { 255 int token; 256 257 if (!*p) 258 continue; 259 token = match_token(p, rescue_tokens, args); 260 switch (token){ 261 case Opt_usebackuproot: 262 btrfs_info(info, 263 "trying to use backup root at mount time"); 264 btrfs_set_opt(info->mount_opt, USEBACKUPROOT); 265 break; 266 case Opt_nologreplay: 267 btrfs_set_and_info(info, NOLOGREPLAY, 268 "disabling log replay at mount time"); 269 break; 270 case Opt_ignorebadroots: 271 btrfs_set_and_info(info, IGNOREBADROOTS, 272 "ignoring bad roots"); 273 break; 274 case Opt_ignoredatacsums: 275 btrfs_set_and_info(info, IGNOREDATACSUMS, 276 "ignoring data csums"); 277 break; 278 case Opt_rescue_all: 279 btrfs_info(info, "enabling all of the rescue options"); 280 btrfs_set_and_info(info, IGNOREDATACSUMS, 281 "ignoring data csums"); 282 btrfs_set_and_info(info, IGNOREBADROOTS, 283 "ignoring bad roots"); 284 btrfs_set_and_info(info, NOLOGREPLAY, 285 "disabling log replay at mount time"); 286 break; 287 case Opt_err: 288 btrfs_info(info, "unrecognized rescue option '%s'", p); 289 ret = -EINVAL; 290 goto out; 291 default: 292 break; 293 } 294 295 } 296 out: 297 kfree(orig); 298 return ret; 299 } 300 301 /* 302 * Regular mount options parser. Everything that is needed only when 303 * reading in a new superblock is parsed here. 304 * XXX JDM: This needs to be cleaned up for remount. 305 */ 306 int btrfs_parse_options(struct btrfs_fs_info *info, char *options, 307 unsigned long new_flags) 308 { 309 substring_t args[MAX_OPT_ARGS]; 310 char *p, *num; 311 int intarg; 312 int ret = 0; 313 char *compress_type; 314 bool compress_force = false; 315 enum btrfs_compression_type saved_compress_type; 316 int saved_compress_level; 317 bool saved_compress_force; 318 int no_compress = 0; 319 const bool remounting = test_bit(BTRFS_FS_STATE_REMOUNTING, &info->fs_state); 320 321 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE)) 322 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE); 323 else if (btrfs_free_space_cache_v1_active(info)) { 324 if (btrfs_is_zoned(info)) { 325 btrfs_info(info, 326 "zoned: clearing existing space cache"); 327 btrfs_set_super_cache_generation(info->super_copy, 0); 328 } else { 329 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 330 } 331 } 332 333 /* 334 * Even the options are empty, we still need to do extra check 335 * against new flags 336 */ 337 if (!options) 338 goto check; 339 340 while ((p = strsep(&options, ",")) != NULL) { 341 int token; 342 if (!*p) 343 continue; 344 345 token = match_token(p, tokens, args); 346 switch (token) { 347 case Opt_degraded: 348 btrfs_info(info, "allowing degraded mounts"); 349 btrfs_set_opt(info->mount_opt, DEGRADED); 350 break; 351 case Opt_subvol: 352 case Opt_subvol_empty: 353 case Opt_subvolid: 354 case Opt_device: 355 /* 356 * These are parsed by btrfs_parse_subvol_options or 357 * btrfs_parse_device_options and can be ignored here. 358 */ 359 break; 360 case Opt_nodatasum: 361 btrfs_set_and_info(info, NODATASUM, 362 "setting nodatasum"); 363 break; 364 case Opt_datasum: 365 if (btrfs_test_opt(info, NODATASUM)) { 366 if (btrfs_test_opt(info, NODATACOW)) 367 btrfs_info(info, 368 "setting datasum, datacow enabled"); 369 else 370 btrfs_info(info, "setting datasum"); 371 } 372 btrfs_clear_opt(info->mount_opt, NODATACOW); 373 btrfs_clear_opt(info->mount_opt, NODATASUM); 374 break; 375 case Opt_nodatacow: 376 if (!btrfs_test_opt(info, NODATACOW)) { 377 if (!btrfs_test_opt(info, COMPRESS) || 378 !btrfs_test_opt(info, FORCE_COMPRESS)) { 379 btrfs_info(info, 380 "setting nodatacow, compression disabled"); 381 } else { 382 btrfs_info(info, "setting nodatacow"); 383 } 384 } 385 btrfs_clear_opt(info->mount_opt, COMPRESS); 386 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 387 btrfs_set_opt(info->mount_opt, NODATACOW); 388 btrfs_set_opt(info->mount_opt, NODATASUM); 389 break; 390 case Opt_datacow: 391 btrfs_clear_and_info(info, NODATACOW, 392 "setting datacow"); 393 break; 394 case Opt_compress_force: 395 case Opt_compress_force_type: 396 compress_force = true; 397 fallthrough; 398 case Opt_compress: 399 case Opt_compress_type: 400 saved_compress_type = btrfs_test_opt(info, 401 COMPRESS) ? 402 info->compress_type : BTRFS_COMPRESS_NONE; 403 saved_compress_force = 404 btrfs_test_opt(info, FORCE_COMPRESS); 405 saved_compress_level = info->compress_level; 406 if (token == Opt_compress || 407 token == Opt_compress_force || 408 strncmp(args[0].from, "zlib", 4) == 0) { 409 compress_type = "zlib"; 410 411 info->compress_type = BTRFS_COMPRESS_ZLIB; 412 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL; 413 /* 414 * args[0] contains uninitialized data since 415 * for these tokens we don't expect any 416 * parameter. 417 */ 418 if (token != Opt_compress && 419 token != Opt_compress_force) 420 info->compress_level = 421 btrfs_compress_str2level( 422 BTRFS_COMPRESS_ZLIB, 423 args[0].from + 4); 424 btrfs_set_opt(info->mount_opt, COMPRESS); 425 btrfs_clear_opt(info->mount_opt, NODATACOW); 426 btrfs_clear_opt(info->mount_opt, NODATASUM); 427 no_compress = 0; 428 } else if (strncmp(args[0].from, "lzo", 3) == 0) { 429 compress_type = "lzo"; 430 info->compress_type = BTRFS_COMPRESS_LZO; 431 info->compress_level = 0; 432 btrfs_set_opt(info->mount_opt, COMPRESS); 433 btrfs_clear_opt(info->mount_opt, NODATACOW); 434 btrfs_clear_opt(info->mount_opt, NODATASUM); 435 btrfs_set_fs_incompat(info, COMPRESS_LZO); 436 no_compress = 0; 437 } else if (strncmp(args[0].from, "zstd", 4) == 0) { 438 compress_type = "zstd"; 439 info->compress_type = BTRFS_COMPRESS_ZSTD; 440 info->compress_level = 441 btrfs_compress_str2level( 442 BTRFS_COMPRESS_ZSTD, 443 args[0].from + 4); 444 btrfs_set_opt(info->mount_opt, COMPRESS); 445 btrfs_clear_opt(info->mount_opt, NODATACOW); 446 btrfs_clear_opt(info->mount_opt, NODATASUM); 447 btrfs_set_fs_incompat(info, COMPRESS_ZSTD); 448 no_compress = 0; 449 } else if (strncmp(args[0].from, "no", 2) == 0) { 450 compress_type = "no"; 451 info->compress_level = 0; 452 info->compress_type = 0; 453 btrfs_clear_opt(info->mount_opt, COMPRESS); 454 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 455 compress_force = false; 456 no_compress++; 457 } else { 458 btrfs_err(info, "unrecognized compression value %s", 459 args[0].from); 460 ret = -EINVAL; 461 goto out; 462 } 463 464 if (compress_force) { 465 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); 466 } else { 467 /* 468 * If we remount from compress-force=xxx to 469 * compress=xxx, we need clear FORCE_COMPRESS 470 * flag, otherwise, there is no way for users 471 * to disable forcible compression separately. 472 */ 473 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 474 } 475 if (no_compress == 1) { 476 btrfs_info(info, "use no compression"); 477 } else if ((info->compress_type != saved_compress_type) || 478 (compress_force != saved_compress_force) || 479 (info->compress_level != saved_compress_level)) { 480 btrfs_info(info, "%s %s compression, level %d", 481 (compress_force) ? "force" : "use", 482 compress_type, info->compress_level); 483 } 484 compress_force = false; 485 break; 486 case Opt_ssd: 487 btrfs_set_and_info(info, SSD, 488 "enabling ssd optimizations"); 489 btrfs_clear_opt(info->mount_opt, NOSSD); 490 break; 491 case Opt_ssd_spread: 492 btrfs_set_and_info(info, SSD, 493 "enabling ssd optimizations"); 494 btrfs_set_and_info(info, SSD_SPREAD, 495 "using spread ssd allocation scheme"); 496 btrfs_clear_opt(info->mount_opt, NOSSD); 497 break; 498 case Opt_nossd: 499 btrfs_set_opt(info->mount_opt, NOSSD); 500 btrfs_clear_and_info(info, SSD, 501 "not using ssd optimizations"); 502 fallthrough; 503 case Opt_nossd_spread: 504 btrfs_clear_and_info(info, SSD_SPREAD, 505 "not using spread ssd allocation scheme"); 506 break; 507 case Opt_barrier: 508 btrfs_clear_and_info(info, NOBARRIER, 509 "turning on barriers"); 510 break; 511 case Opt_nobarrier: 512 btrfs_set_and_info(info, NOBARRIER, 513 "turning off barriers"); 514 break; 515 case Opt_thread_pool: 516 ret = match_int(&args[0], &intarg); 517 if (ret) { 518 btrfs_err(info, "unrecognized thread_pool value %s", 519 args[0].from); 520 goto out; 521 } else if (intarg == 0) { 522 btrfs_err(info, "invalid value 0 for thread_pool"); 523 ret = -EINVAL; 524 goto out; 525 } 526 info->thread_pool_size = intarg; 527 break; 528 case Opt_max_inline: 529 num = match_strdup(&args[0]); 530 if (num) { 531 info->max_inline = memparse(num, NULL); 532 kfree(num); 533 534 if (info->max_inline) { 535 info->max_inline = min_t(u64, 536 info->max_inline, 537 info->sectorsize); 538 } 539 btrfs_info(info, "max_inline at %llu", 540 info->max_inline); 541 } else { 542 ret = -ENOMEM; 543 goto out; 544 } 545 break; 546 case Opt_acl: 547 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 548 info->sb->s_flags |= SB_POSIXACL; 549 break; 550 #else 551 btrfs_err(info, "support for ACL not compiled in!"); 552 ret = -EINVAL; 553 goto out; 554 #endif 555 case Opt_noacl: 556 info->sb->s_flags &= ~SB_POSIXACL; 557 break; 558 case Opt_notreelog: 559 btrfs_set_and_info(info, NOTREELOG, 560 "disabling tree log"); 561 break; 562 case Opt_treelog: 563 btrfs_clear_and_info(info, NOTREELOG, 564 "enabling tree log"); 565 break; 566 case Opt_norecovery: 567 case Opt_nologreplay: 568 btrfs_warn(info, 569 "'nologreplay' is deprecated, use 'rescue=nologreplay' instead"); 570 btrfs_set_and_info(info, NOLOGREPLAY, 571 "disabling log replay at mount time"); 572 break; 573 case Opt_flushoncommit: 574 btrfs_set_and_info(info, FLUSHONCOMMIT, 575 "turning on flush-on-commit"); 576 break; 577 case Opt_noflushoncommit: 578 btrfs_clear_and_info(info, FLUSHONCOMMIT, 579 "turning off flush-on-commit"); 580 break; 581 case Opt_ratio: 582 ret = match_int(&args[0], &intarg); 583 if (ret) { 584 btrfs_err(info, "unrecognized metadata_ratio value %s", 585 args[0].from); 586 goto out; 587 } 588 info->metadata_ratio = intarg; 589 btrfs_info(info, "metadata ratio %u", 590 info->metadata_ratio); 591 break; 592 case Opt_discard: 593 case Opt_discard_mode: 594 if (token == Opt_discard || 595 strcmp(args[0].from, "sync") == 0) { 596 btrfs_clear_opt(info->mount_opt, DISCARD_ASYNC); 597 btrfs_set_and_info(info, DISCARD_SYNC, 598 "turning on sync discard"); 599 } else if (strcmp(args[0].from, "async") == 0) { 600 btrfs_clear_opt(info->mount_opt, DISCARD_SYNC); 601 btrfs_set_and_info(info, DISCARD_ASYNC, 602 "turning on async discard"); 603 } else { 604 btrfs_err(info, "unrecognized discard mode value %s", 605 args[0].from); 606 ret = -EINVAL; 607 goto out; 608 } 609 btrfs_clear_opt(info->mount_opt, NODISCARD); 610 break; 611 case Opt_nodiscard: 612 btrfs_clear_and_info(info, DISCARD_SYNC, 613 "turning off discard"); 614 btrfs_clear_and_info(info, DISCARD_ASYNC, 615 "turning off async discard"); 616 btrfs_set_opt(info->mount_opt, NODISCARD); 617 break; 618 case Opt_space_cache: 619 case Opt_space_cache_version: 620 /* 621 * We already set FREE_SPACE_TREE above because we have 622 * compat_ro(FREE_SPACE_TREE) set, and we aren't going 623 * to allow v1 to be set for extent tree v2, simply 624 * ignore this setting if we're extent tree v2. 625 */ 626 if (btrfs_fs_incompat(info, EXTENT_TREE_V2)) 627 break; 628 if (token == Opt_space_cache || 629 strcmp(args[0].from, "v1") == 0) { 630 btrfs_clear_opt(info->mount_opt, 631 FREE_SPACE_TREE); 632 btrfs_set_and_info(info, SPACE_CACHE, 633 "enabling disk space caching"); 634 } else if (strcmp(args[0].from, "v2") == 0) { 635 btrfs_clear_opt(info->mount_opt, 636 SPACE_CACHE); 637 btrfs_set_and_info(info, FREE_SPACE_TREE, 638 "enabling free space tree"); 639 } else { 640 btrfs_err(info, "unrecognized space_cache value %s", 641 args[0].from); 642 ret = -EINVAL; 643 goto out; 644 } 645 break; 646 case Opt_rescan_uuid_tree: 647 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE); 648 break; 649 case Opt_no_space_cache: 650 /* 651 * We cannot operate without the free space tree with 652 * extent tree v2, ignore this option. 653 */ 654 if (btrfs_fs_incompat(info, EXTENT_TREE_V2)) 655 break; 656 if (btrfs_test_opt(info, SPACE_CACHE)) { 657 btrfs_clear_and_info(info, SPACE_CACHE, 658 "disabling disk space caching"); 659 } 660 if (btrfs_test_opt(info, FREE_SPACE_TREE)) { 661 btrfs_clear_and_info(info, FREE_SPACE_TREE, 662 "disabling free space tree"); 663 } 664 break; 665 case Opt_inode_cache: 666 case Opt_noinode_cache: 667 btrfs_warn(info, 668 "the 'inode_cache' option is deprecated and has no effect since 5.11"); 669 break; 670 case Opt_clear_cache: 671 /* 672 * We cannot clear the free space tree with extent tree 673 * v2, ignore this option. 674 */ 675 if (btrfs_fs_incompat(info, EXTENT_TREE_V2)) 676 break; 677 btrfs_set_and_info(info, CLEAR_CACHE, 678 "force clearing of disk cache"); 679 break; 680 case Opt_user_subvol_rm_allowed: 681 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 682 break; 683 case Opt_enospc_debug: 684 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 685 break; 686 case Opt_noenospc_debug: 687 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG); 688 break; 689 case Opt_defrag: 690 btrfs_set_and_info(info, AUTO_DEFRAG, 691 "enabling auto defrag"); 692 break; 693 case Opt_nodefrag: 694 btrfs_clear_and_info(info, AUTO_DEFRAG, 695 "disabling auto defrag"); 696 break; 697 case Opt_recovery: 698 case Opt_usebackuproot: 699 btrfs_warn(info, 700 "'%s' is deprecated, use 'rescue=usebackuproot' instead", 701 token == Opt_recovery ? "recovery" : 702 "usebackuproot"); 703 btrfs_info(info, 704 "trying to use backup root at mount time"); 705 btrfs_set_opt(info->mount_opt, USEBACKUPROOT); 706 break; 707 case Opt_skip_balance: 708 btrfs_set_opt(info->mount_opt, SKIP_BALANCE); 709 break; 710 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 711 case Opt_check_integrity_including_extent_data: 712 btrfs_warn(info, 713 "integrity checker is deprecated and will be removed in 6.7"); 714 btrfs_info(info, 715 "enabling check integrity including extent data"); 716 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY_DATA); 717 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 718 break; 719 case Opt_check_integrity: 720 btrfs_warn(info, 721 "integrity checker is deprecated and will be removed in 6.7"); 722 btrfs_info(info, "enabling check integrity"); 723 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 724 break; 725 case Opt_check_integrity_print_mask: 726 ret = match_int(&args[0], &intarg); 727 if (ret) { 728 btrfs_err(info, 729 "unrecognized check_integrity_print_mask value %s", 730 args[0].from); 731 goto out; 732 } 733 info->check_integrity_print_mask = intarg; 734 btrfs_warn(info, 735 "integrity checker is deprecated and will be removed in 6.7"); 736 btrfs_info(info, "check_integrity_print_mask 0x%x", 737 info->check_integrity_print_mask); 738 break; 739 #else 740 case Opt_check_integrity_including_extent_data: 741 case Opt_check_integrity: 742 case Opt_check_integrity_print_mask: 743 btrfs_err(info, 744 "support for check_integrity* not compiled in!"); 745 ret = -EINVAL; 746 goto out; 747 #endif 748 case Opt_fatal_errors: 749 if (strcmp(args[0].from, "panic") == 0) { 750 btrfs_set_opt(info->mount_opt, 751 PANIC_ON_FATAL_ERROR); 752 } else if (strcmp(args[0].from, "bug") == 0) { 753 btrfs_clear_opt(info->mount_opt, 754 PANIC_ON_FATAL_ERROR); 755 } else { 756 btrfs_err(info, "unrecognized fatal_errors value %s", 757 args[0].from); 758 ret = -EINVAL; 759 goto out; 760 } 761 break; 762 case Opt_commit_interval: 763 intarg = 0; 764 ret = match_int(&args[0], &intarg); 765 if (ret) { 766 btrfs_err(info, "unrecognized commit_interval value %s", 767 args[0].from); 768 ret = -EINVAL; 769 goto out; 770 } 771 if (intarg == 0) { 772 btrfs_info(info, 773 "using default commit interval %us", 774 BTRFS_DEFAULT_COMMIT_INTERVAL); 775 intarg = BTRFS_DEFAULT_COMMIT_INTERVAL; 776 } else if (intarg > 300) { 777 btrfs_warn(info, "excessive commit interval %d", 778 intarg); 779 } 780 info->commit_interval = intarg; 781 break; 782 case Opt_rescue: 783 ret = parse_rescue_options(info, args[0].from); 784 if (ret < 0) { 785 btrfs_err(info, "unrecognized rescue value %s", 786 args[0].from); 787 goto out; 788 } 789 break; 790 #ifdef CONFIG_BTRFS_DEBUG 791 case Opt_fragment_all: 792 btrfs_info(info, "fragmenting all space"); 793 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 794 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA); 795 break; 796 case Opt_fragment_metadata: 797 btrfs_info(info, "fragmenting metadata"); 798 btrfs_set_opt(info->mount_opt, 799 FRAGMENT_METADATA); 800 break; 801 case Opt_fragment_data: 802 btrfs_info(info, "fragmenting data"); 803 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 804 break; 805 #endif 806 #ifdef CONFIG_BTRFS_FS_REF_VERIFY 807 case Opt_ref_verify: 808 btrfs_info(info, "doing ref verification"); 809 btrfs_set_opt(info->mount_opt, REF_VERIFY); 810 break; 811 #endif 812 case Opt_err: 813 btrfs_err(info, "unrecognized mount option '%s'", p); 814 ret = -EINVAL; 815 goto out; 816 default: 817 break; 818 } 819 } 820 check: 821 /* We're read-only, don't have to check. */ 822 if (new_flags & SB_RDONLY) 823 goto out; 824 825 if (check_ro_option(info, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") || 826 check_ro_option(info, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") || 827 check_ro_option(info, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums")) 828 ret = -EINVAL; 829 out: 830 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) && 831 !btrfs_test_opt(info, FREE_SPACE_TREE) && 832 !btrfs_test_opt(info, CLEAR_CACHE)) { 833 btrfs_err(info, "cannot disable free space tree"); 834 ret = -EINVAL; 835 } 836 if (btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE) && 837 !btrfs_test_opt(info, FREE_SPACE_TREE)) { 838 btrfs_err(info, "cannot disable free space tree with block-group-tree feature"); 839 ret = -EINVAL; 840 } 841 if (!ret) 842 ret = btrfs_check_mountopts_zoned(info); 843 if (!ret && !remounting) { 844 if (btrfs_test_opt(info, SPACE_CACHE)) 845 btrfs_info(info, "disk space caching is enabled"); 846 if (btrfs_test_opt(info, FREE_SPACE_TREE)) 847 btrfs_info(info, "using free space tree"); 848 } 849 return ret; 850 } 851 852 /* 853 * Parse mount options that are required early in the mount process. 854 * 855 * All other options will be parsed on much later in the mount process and 856 * only when we need to allocate a new super block. 857 */ 858 static int btrfs_parse_device_options(const char *options, blk_mode_t flags) 859 { 860 substring_t args[MAX_OPT_ARGS]; 861 char *device_name, *opts, *orig, *p; 862 struct btrfs_device *device = NULL; 863 int error = 0; 864 865 lockdep_assert_held(&uuid_mutex); 866 867 if (!options) 868 return 0; 869 870 /* 871 * strsep changes the string, duplicate it because btrfs_parse_options 872 * gets called later 873 */ 874 opts = kstrdup(options, GFP_KERNEL); 875 if (!opts) 876 return -ENOMEM; 877 orig = opts; 878 879 while ((p = strsep(&opts, ",")) != NULL) { 880 int token; 881 882 if (!*p) 883 continue; 884 885 token = match_token(p, tokens, args); 886 if (token == Opt_device) { 887 device_name = match_strdup(&args[0]); 888 if (!device_name) { 889 error = -ENOMEM; 890 goto out; 891 } 892 device = btrfs_scan_one_device(device_name, flags); 893 kfree(device_name); 894 if (IS_ERR(device)) { 895 error = PTR_ERR(device); 896 goto out; 897 } 898 } 899 } 900 901 out: 902 kfree(orig); 903 return error; 904 } 905 906 /* 907 * Parse mount options that are related to subvolume id 908 * 909 * The value is later passed to mount_subvol() 910 */ 911 static int btrfs_parse_subvol_options(const char *options, char **subvol_name, 912 u64 *subvol_objectid) 913 { 914 substring_t args[MAX_OPT_ARGS]; 915 char *opts, *orig, *p; 916 int error = 0; 917 u64 subvolid; 918 919 if (!options) 920 return 0; 921 922 /* 923 * strsep changes the string, duplicate it because 924 * btrfs_parse_device_options gets called later 925 */ 926 opts = kstrdup(options, GFP_KERNEL); 927 if (!opts) 928 return -ENOMEM; 929 orig = opts; 930 931 while ((p = strsep(&opts, ",")) != NULL) { 932 int token; 933 if (!*p) 934 continue; 935 936 token = match_token(p, tokens, args); 937 switch (token) { 938 case Opt_subvol: 939 kfree(*subvol_name); 940 *subvol_name = match_strdup(&args[0]); 941 if (!*subvol_name) { 942 error = -ENOMEM; 943 goto out; 944 } 945 break; 946 case Opt_subvolid: 947 error = match_u64(&args[0], &subvolid); 948 if (error) 949 goto out; 950 951 /* we want the original fs_tree */ 952 if (subvolid == 0) 953 subvolid = BTRFS_FS_TREE_OBJECTID; 954 955 *subvol_objectid = subvolid; 956 break; 957 default: 958 break; 959 } 960 } 961 962 out: 963 kfree(orig); 964 return error; 965 } 966 967 char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, 968 u64 subvol_objectid) 969 { 970 struct btrfs_root *root = fs_info->tree_root; 971 struct btrfs_root *fs_root = NULL; 972 struct btrfs_root_ref *root_ref; 973 struct btrfs_inode_ref *inode_ref; 974 struct btrfs_key key; 975 struct btrfs_path *path = NULL; 976 char *name = NULL, *ptr; 977 u64 dirid; 978 int len; 979 int ret; 980 981 path = btrfs_alloc_path(); 982 if (!path) { 983 ret = -ENOMEM; 984 goto err; 985 } 986 987 name = kmalloc(PATH_MAX, GFP_KERNEL); 988 if (!name) { 989 ret = -ENOMEM; 990 goto err; 991 } 992 ptr = name + PATH_MAX - 1; 993 ptr[0] = '\0'; 994 995 /* 996 * Walk up the subvolume trees in the tree of tree roots by root 997 * backrefs until we hit the top-level subvolume. 998 */ 999 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) { 1000 key.objectid = subvol_objectid; 1001 key.type = BTRFS_ROOT_BACKREF_KEY; 1002 key.offset = (u64)-1; 1003 1004 ret = btrfs_search_backwards(root, &key, path); 1005 if (ret < 0) { 1006 goto err; 1007 } else if (ret > 0) { 1008 ret = -ENOENT; 1009 goto err; 1010 } 1011 1012 subvol_objectid = key.offset; 1013 1014 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 1015 struct btrfs_root_ref); 1016 len = btrfs_root_ref_name_len(path->nodes[0], root_ref); 1017 ptr -= len + 1; 1018 if (ptr < name) { 1019 ret = -ENAMETOOLONG; 1020 goto err; 1021 } 1022 read_extent_buffer(path->nodes[0], ptr + 1, 1023 (unsigned long)(root_ref + 1), len); 1024 ptr[0] = '/'; 1025 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref); 1026 btrfs_release_path(path); 1027 1028 fs_root = btrfs_get_fs_root(fs_info, subvol_objectid, true); 1029 if (IS_ERR(fs_root)) { 1030 ret = PTR_ERR(fs_root); 1031 fs_root = NULL; 1032 goto err; 1033 } 1034 1035 /* 1036 * Walk up the filesystem tree by inode refs until we hit the 1037 * root directory. 1038 */ 1039 while (dirid != BTRFS_FIRST_FREE_OBJECTID) { 1040 key.objectid = dirid; 1041 key.type = BTRFS_INODE_REF_KEY; 1042 key.offset = (u64)-1; 1043 1044 ret = btrfs_search_backwards(fs_root, &key, path); 1045 if (ret < 0) { 1046 goto err; 1047 } else if (ret > 0) { 1048 ret = -ENOENT; 1049 goto err; 1050 } 1051 1052 dirid = key.offset; 1053 1054 inode_ref = btrfs_item_ptr(path->nodes[0], 1055 path->slots[0], 1056 struct btrfs_inode_ref); 1057 len = btrfs_inode_ref_name_len(path->nodes[0], 1058 inode_ref); 1059 ptr -= len + 1; 1060 if (ptr < name) { 1061 ret = -ENAMETOOLONG; 1062 goto err; 1063 } 1064 read_extent_buffer(path->nodes[0], ptr + 1, 1065 (unsigned long)(inode_ref + 1), len); 1066 ptr[0] = '/'; 1067 btrfs_release_path(path); 1068 } 1069 btrfs_put_root(fs_root); 1070 fs_root = NULL; 1071 } 1072 1073 btrfs_free_path(path); 1074 if (ptr == name + PATH_MAX - 1) { 1075 name[0] = '/'; 1076 name[1] = '\0'; 1077 } else { 1078 memmove(name, ptr, name + PATH_MAX - ptr); 1079 } 1080 return name; 1081 1082 err: 1083 btrfs_put_root(fs_root); 1084 btrfs_free_path(path); 1085 kfree(name); 1086 return ERR_PTR(ret); 1087 } 1088 1089 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid) 1090 { 1091 struct btrfs_root *root = fs_info->tree_root; 1092 struct btrfs_dir_item *di; 1093 struct btrfs_path *path; 1094 struct btrfs_key location; 1095 struct fscrypt_str name = FSTR_INIT("default", 7); 1096 u64 dir_id; 1097 1098 path = btrfs_alloc_path(); 1099 if (!path) 1100 return -ENOMEM; 1101 1102 /* 1103 * Find the "default" dir item which points to the root item that we 1104 * will mount by default if we haven't been given a specific subvolume 1105 * to mount. 1106 */ 1107 dir_id = btrfs_super_root_dir(fs_info->super_copy); 1108 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, &name, 0); 1109 if (IS_ERR(di)) { 1110 btrfs_free_path(path); 1111 return PTR_ERR(di); 1112 } 1113 if (!di) { 1114 /* 1115 * Ok the default dir item isn't there. This is weird since 1116 * it's always been there, but don't freak out, just try and 1117 * mount the top-level subvolume. 1118 */ 1119 btrfs_free_path(path); 1120 *objectid = BTRFS_FS_TREE_OBJECTID; 1121 return 0; 1122 } 1123 1124 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 1125 btrfs_free_path(path); 1126 *objectid = location.objectid; 1127 return 0; 1128 } 1129 1130 static int btrfs_fill_super(struct super_block *sb, 1131 struct btrfs_fs_devices *fs_devices, 1132 void *data) 1133 { 1134 struct inode *inode; 1135 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1136 int err; 1137 1138 sb->s_maxbytes = MAX_LFS_FILESIZE; 1139 sb->s_magic = BTRFS_SUPER_MAGIC; 1140 sb->s_op = &btrfs_super_ops; 1141 sb->s_d_op = &btrfs_dentry_operations; 1142 sb->s_export_op = &btrfs_export_ops; 1143 #ifdef CONFIG_FS_VERITY 1144 sb->s_vop = &btrfs_verityops; 1145 #endif 1146 sb->s_xattr = btrfs_xattr_handlers; 1147 sb->s_time_gran = 1; 1148 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 1149 sb->s_flags |= SB_POSIXACL; 1150 #endif 1151 sb->s_flags |= SB_I_VERSION; 1152 sb->s_iflags |= SB_I_CGROUPWB; 1153 1154 err = super_setup_bdi(sb); 1155 if (err) { 1156 btrfs_err(fs_info, "super_setup_bdi failed"); 1157 return err; 1158 } 1159 1160 err = open_ctree(sb, fs_devices, (char *)data); 1161 if (err) { 1162 btrfs_err(fs_info, "open_ctree failed"); 1163 return err; 1164 } 1165 1166 inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root); 1167 if (IS_ERR(inode)) { 1168 err = PTR_ERR(inode); 1169 btrfs_handle_fs_error(fs_info, err, NULL); 1170 goto fail_close; 1171 } 1172 1173 sb->s_root = d_make_root(inode); 1174 if (!sb->s_root) { 1175 err = -ENOMEM; 1176 goto fail_close; 1177 } 1178 1179 sb->s_flags |= SB_ACTIVE; 1180 return 0; 1181 1182 fail_close: 1183 close_ctree(fs_info); 1184 return err; 1185 } 1186 1187 int btrfs_sync_fs(struct super_block *sb, int wait) 1188 { 1189 struct btrfs_trans_handle *trans; 1190 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1191 struct btrfs_root *root = fs_info->tree_root; 1192 1193 trace_btrfs_sync_fs(fs_info, wait); 1194 1195 if (!wait) { 1196 filemap_flush(fs_info->btree_inode->i_mapping); 1197 return 0; 1198 } 1199 1200 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 1201 1202 trans = btrfs_attach_transaction_barrier(root); 1203 if (IS_ERR(trans)) { 1204 /* no transaction, don't bother */ 1205 if (PTR_ERR(trans) == -ENOENT) { 1206 /* 1207 * Exit unless we have some pending changes 1208 * that need to go through commit 1209 */ 1210 if (!test_bit(BTRFS_FS_NEED_TRANS_COMMIT, 1211 &fs_info->flags)) 1212 return 0; 1213 /* 1214 * A non-blocking test if the fs is frozen. We must not 1215 * start a new transaction here otherwise a deadlock 1216 * happens. The pending operations are delayed to the 1217 * next commit after thawing. 1218 */ 1219 if (sb_start_write_trylock(sb)) 1220 sb_end_write(sb); 1221 else 1222 return 0; 1223 trans = btrfs_start_transaction(root, 0); 1224 } 1225 if (IS_ERR(trans)) 1226 return PTR_ERR(trans); 1227 } 1228 return btrfs_commit_transaction(trans); 1229 } 1230 1231 static void print_rescue_option(struct seq_file *seq, const char *s, bool *printed) 1232 { 1233 seq_printf(seq, "%s%s", (*printed) ? ":" : ",rescue=", s); 1234 *printed = true; 1235 } 1236 1237 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) 1238 { 1239 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); 1240 const char *compress_type; 1241 const char *subvol_name; 1242 bool printed = false; 1243 1244 if (btrfs_test_opt(info, DEGRADED)) 1245 seq_puts(seq, ",degraded"); 1246 if (btrfs_test_opt(info, NODATASUM)) 1247 seq_puts(seq, ",nodatasum"); 1248 if (btrfs_test_opt(info, NODATACOW)) 1249 seq_puts(seq, ",nodatacow"); 1250 if (btrfs_test_opt(info, NOBARRIER)) 1251 seq_puts(seq, ",nobarrier"); 1252 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) 1253 seq_printf(seq, ",max_inline=%llu", info->max_inline); 1254 if (info->thread_pool_size != min_t(unsigned long, 1255 num_online_cpus() + 2, 8)) 1256 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size); 1257 if (btrfs_test_opt(info, COMPRESS)) { 1258 compress_type = btrfs_compress_type2str(info->compress_type); 1259 if (btrfs_test_opt(info, FORCE_COMPRESS)) 1260 seq_printf(seq, ",compress-force=%s", compress_type); 1261 else 1262 seq_printf(seq, ",compress=%s", compress_type); 1263 if (info->compress_level) 1264 seq_printf(seq, ":%d", info->compress_level); 1265 } 1266 if (btrfs_test_opt(info, NOSSD)) 1267 seq_puts(seq, ",nossd"); 1268 if (btrfs_test_opt(info, SSD_SPREAD)) 1269 seq_puts(seq, ",ssd_spread"); 1270 else if (btrfs_test_opt(info, SSD)) 1271 seq_puts(seq, ",ssd"); 1272 if (btrfs_test_opt(info, NOTREELOG)) 1273 seq_puts(seq, ",notreelog"); 1274 if (btrfs_test_opt(info, NOLOGREPLAY)) 1275 print_rescue_option(seq, "nologreplay", &printed); 1276 if (btrfs_test_opt(info, USEBACKUPROOT)) 1277 print_rescue_option(seq, "usebackuproot", &printed); 1278 if (btrfs_test_opt(info, IGNOREBADROOTS)) 1279 print_rescue_option(seq, "ignorebadroots", &printed); 1280 if (btrfs_test_opt(info, IGNOREDATACSUMS)) 1281 print_rescue_option(seq, "ignoredatacsums", &printed); 1282 if (btrfs_test_opt(info, FLUSHONCOMMIT)) 1283 seq_puts(seq, ",flushoncommit"); 1284 if (btrfs_test_opt(info, DISCARD_SYNC)) 1285 seq_puts(seq, ",discard"); 1286 if (btrfs_test_opt(info, DISCARD_ASYNC)) 1287 seq_puts(seq, ",discard=async"); 1288 if (!(info->sb->s_flags & SB_POSIXACL)) 1289 seq_puts(seq, ",noacl"); 1290 if (btrfs_free_space_cache_v1_active(info)) 1291 seq_puts(seq, ",space_cache"); 1292 else if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE)) 1293 seq_puts(seq, ",space_cache=v2"); 1294 else 1295 seq_puts(seq, ",nospace_cache"); 1296 if (btrfs_test_opt(info, RESCAN_UUID_TREE)) 1297 seq_puts(seq, ",rescan_uuid_tree"); 1298 if (btrfs_test_opt(info, CLEAR_CACHE)) 1299 seq_puts(seq, ",clear_cache"); 1300 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED)) 1301 seq_puts(seq, ",user_subvol_rm_allowed"); 1302 if (btrfs_test_opt(info, ENOSPC_DEBUG)) 1303 seq_puts(seq, ",enospc_debug"); 1304 if (btrfs_test_opt(info, AUTO_DEFRAG)) 1305 seq_puts(seq, ",autodefrag"); 1306 if (btrfs_test_opt(info, SKIP_BALANCE)) 1307 seq_puts(seq, ",skip_balance"); 1308 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 1309 if (btrfs_test_opt(info, CHECK_INTEGRITY_DATA)) 1310 seq_puts(seq, ",check_int_data"); 1311 else if (btrfs_test_opt(info, CHECK_INTEGRITY)) 1312 seq_puts(seq, ",check_int"); 1313 if (info->check_integrity_print_mask) 1314 seq_printf(seq, ",check_int_print_mask=%d", 1315 info->check_integrity_print_mask); 1316 #endif 1317 if (info->metadata_ratio) 1318 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio); 1319 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR)) 1320 seq_puts(seq, ",fatal_errors=panic"); 1321 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) 1322 seq_printf(seq, ",commit=%u", info->commit_interval); 1323 #ifdef CONFIG_BTRFS_DEBUG 1324 if (btrfs_test_opt(info, FRAGMENT_DATA)) 1325 seq_puts(seq, ",fragment=data"); 1326 if (btrfs_test_opt(info, FRAGMENT_METADATA)) 1327 seq_puts(seq, ",fragment=metadata"); 1328 #endif 1329 if (btrfs_test_opt(info, REF_VERIFY)) 1330 seq_puts(seq, ",ref_verify"); 1331 seq_printf(seq, ",subvolid=%llu", 1332 BTRFS_I(d_inode(dentry))->root->root_key.objectid); 1333 subvol_name = btrfs_get_subvol_name_from_objectid(info, 1334 BTRFS_I(d_inode(dentry))->root->root_key.objectid); 1335 if (!IS_ERR(subvol_name)) { 1336 seq_puts(seq, ",subvol="); 1337 seq_escape(seq, subvol_name, " \t\n\\"); 1338 kfree(subvol_name); 1339 } 1340 return 0; 1341 } 1342 1343 static int btrfs_test_super(struct super_block *s, void *data) 1344 { 1345 struct btrfs_fs_info *p = data; 1346 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1347 1348 return fs_info->fs_devices == p->fs_devices; 1349 } 1350 1351 static int btrfs_set_super(struct super_block *s, void *data) 1352 { 1353 int err = set_anon_super(s, data); 1354 if (!err) 1355 s->s_fs_info = data; 1356 return err; 1357 } 1358 1359 /* 1360 * subvolumes are identified by ino 256 1361 */ 1362 static inline int is_subvolume_inode(struct inode *inode) 1363 { 1364 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 1365 return 1; 1366 return 0; 1367 } 1368 1369 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid, 1370 struct vfsmount *mnt) 1371 { 1372 struct dentry *root; 1373 int ret; 1374 1375 if (!subvol_name) { 1376 if (!subvol_objectid) { 1377 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb), 1378 &subvol_objectid); 1379 if (ret) { 1380 root = ERR_PTR(ret); 1381 goto out; 1382 } 1383 } 1384 subvol_name = btrfs_get_subvol_name_from_objectid( 1385 btrfs_sb(mnt->mnt_sb), subvol_objectid); 1386 if (IS_ERR(subvol_name)) { 1387 root = ERR_CAST(subvol_name); 1388 subvol_name = NULL; 1389 goto out; 1390 } 1391 1392 } 1393 1394 root = mount_subtree(mnt, subvol_name); 1395 /* mount_subtree() drops our reference on the vfsmount. */ 1396 mnt = NULL; 1397 1398 if (!IS_ERR(root)) { 1399 struct super_block *s = root->d_sb; 1400 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1401 struct inode *root_inode = d_inode(root); 1402 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid; 1403 1404 ret = 0; 1405 if (!is_subvolume_inode(root_inode)) { 1406 btrfs_err(fs_info, "'%s' is not a valid subvolume", 1407 subvol_name); 1408 ret = -EINVAL; 1409 } 1410 if (subvol_objectid && root_objectid != subvol_objectid) { 1411 /* 1412 * This will also catch a race condition where a 1413 * subvolume which was passed by ID is renamed and 1414 * another subvolume is renamed over the old location. 1415 */ 1416 btrfs_err(fs_info, 1417 "subvol '%s' does not match subvolid %llu", 1418 subvol_name, subvol_objectid); 1419 ret = -EINVAL; 1420 } 1421 if (ret) { 1422 dput(root); 1423 root = ERR_PTR(ret); 1424 deactivate_locked_super(s); 1425 } 1426 } 1427 1428 out: 1429 mntput(mnt); 1430 kfree(subvol_name); 1431 return root; 1432 } 1433 1434 /* 1435 * Find a superblock for the given device / mount point. 1436 * 1437 * Note: This is based on mount_bdev from fs/super.c with a few additions 1438 * for multiple device setup. Make sure to keep it in sync. 1439 */ 1440 static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, 1441 int flags, const char *device_name, void *data) 1442 { 1443 struct block_device *bdev = NULL; 1444 struct super_block *s; 1445 struct btrfs_device *device = NULL; 1446 struct btrfs_fs_devices *fs_devices = NULL; 1447 struct btrfs_fs_info *fs_info = NULL; 1448 void *new_sec_opts = NULL; 1449 blk_mode_t mode = sb_open_mode(flags); 1450 int error = 0; 1451 1452 if (data) { 1453 error = security_sb_eat_lsm_opts(data, &new_sec_opts); 1454 if (error) 1455 return ERR_PTR(error); 1456 } 1457 1458 /* 1459 * Setup a dummy root and fs_info for test/set super. This is because 1460 * we don't actually fill this stuff out until open_ctree, but we need 1461 * then open_ctree will properly initialize the file system specific 1462 * settings later. btrfs_init_fs_info initializes the static elements 1463 * of the fs_info (locks and such) to make cleanup easier if we find a 1464 * superblock with our given fs_devices later on at sget() time. 1465 */ 1466 fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL); 1467 if (!fs_info) { 1468 error = -ENOMEM; 1469 goto error_sec_opts; 1470 } 1471 btrfs_init_fs_info(fs_info); 1472 1473 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); 1474 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); 1475 if (!fs_info->super_copy || !fs_info->super_for_commit) { 1476 error = -ENOMEM; 1477 goto error_fs_info; 1478 } 1479 1480 mutex_lock(&uuid_mutex); 1481 error = btrfs_parse_device_options(data, mode); 1482 if (error) { 1483 mutex_unlock(&uuid_mutex); 1484 goto error_fs_info; 1485 } 1486 1487 device = btrfs_scan_one_device(device_name, mode); 1488 if (IS_ERR(device)) { 1489 mutex_unlock(&uuid_mutex); 1490 error = PTR_ERR(device); 1491 goto error_fs_info; 1492 } 1493 1494 fs_devices = device->fs_devices; 1495 fs_info->fs_devices = fs_devices; 1496 1497 error = btrfs_open_devices(fs_devices, mode, fs_type); 1498 mutex_unlock(&uuid_mutex); 1499 if (error) 1500 goto error_fs_info; 1501 1502 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) { 1503 error = -EACCES; 1504 goto error_close_devices; 1505 } 1506 1507 bdev = fs_devices->latest_dev->bdev; 1508 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC, 1509 fs_info); 1510 if (IS_ERR(s)) { 1511 error = PTR_ERR(s); 1512 goto error_close_devices; 1513 } 1514 1515 if (s->s_root) { 1516 btrfs_close_devices(fs_devices); 1517 btrfs_free_fs_info(fs_info); 1518 if ((flags ^ s->s_flags) & SB_RDONLY) 1519 error = -EBUSY; 1520 } else { 1521 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); 1522 shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s", fs_type->name, 1523 s->s_id); 1524 btrfs_sb(s)->bdev_holder = fs_type; 1525 error = btrfs_fill_super(s, fs_devices, data); 1526 } 1527 if (!error) 1528 error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL); 1529 security_free_mnt_opts(&new_sec_opts); 1530 if (error) { 1531 deactivate_locked_super(s); 1532 return ERR_PTR(error); 1533 } 1534 1535 return dget(s->s_root); 1536 1537 error_close_devices: 1538 btrfs_close_devices(fs_devices); 1539 error_fs_info: 1540 btrfs_free_fs_info(fs_info); 1541 error_sec_opts: 1542 security_free_mnt_opts(&new_sec_opts); 1543 return ERR_PTR(error); 1544 } 1545 1546 /* 1547 * Mount function which is called by VFS layer. 1548 * 1549 * In order to allow mounting a subvolume directly, btrfs uses mount_subtree() 1550 * which needs vfsmount* of device's root (/). This means device's root has to 1551 * be mounted internally in any case. 1552 * 1553 * Operation flow: 1554 * 1. Parse subvol id related options for later use in mount_subvol(). 1555 * 1556 * 2. Mount device's root (/) by calling vfs_kern_mount(). 1557 * 1558 * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the 1559 * first place. In order to avoid calling btrfs_mount() again, we use 1560 * different file_system_type which is not registered to VFS by 1561 * register_filesystem() (btrfs_root_fs_type). As a result, 1562 * btrfs_mount_root() is called. The return value will be used by 1563 * mount_subtree() in mount_subvol(). 1564 * 1565 * 3. Call mount_subvol() to get the dentry of subvolume. Since there is 1566 * "btrfs subvolume set-default", mount_subvol() is called always. 1567 */ 1568 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 1569 const char *device_name, void *data) 1570 { 1571 struct vfsmount *mnt_root; 1572 struct dentry *root; 1573 char *subvol_name = NULL; 1574 u64 subvol_objectid = 0; 1575 int error = 0; 1576 1577 error = btrfs_parse_subvol_options(data, &subvol_name, 1578 &subvol_objectid); 1579 if (error) { 1580 kfree(subvol_name); 1581 return ERR_PTR(error); 1582 } 1583 1584 /* mount device's root (/) */ 1585 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data); 1586 if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) { 1587 if (flags & SB_RDONLY) { 1588 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, 1589 flags & ~SB_RDONLY, device_name, data); 1590 } else { 1591 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, 1592 flags | SB_RDONLY, device_name, data); 1593 if (IS_ERR(mnt_root)) { 1594 root = ERR_CAST(mnt_root); 1595 kfree(subvol_name); 1596 goto out; 1597 } 1598 1599 down_write(&mnt_root->mnt_sb->s_umount); 1600 error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL); 1601 up_write(&mnt_root->mnt_sb->s_umount); 1602 if (error < 0) { 1603 root = ERR_PTR(error); 1604 mntput(mnt_root); 1605 kfree(subvol_name); 1606 goto out; 1607 } 1608 } 1609 } 1610 if (IS_ERR(mnt_root)) { 1611 root = ERR_CAST(mnt_root); 1612 kfree(subvol_name); 1613 goto out; 1614 } 1615 1616 /* mount_subvol() will free subvol_name and mnt_root */ 1617 root = mount_subvol(subvol_name, subvol_objectid, mnt_root); 1618 1619 out: 1620 return root; 1621 } 1622 1623 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, 1624 u32 new_pool_size, u32 old_pool_size) 1625 { 1626 if (new_pool_size == old_pool_size) 1627 return; 1628 1629 fs_info->thread_pool_size = new_pool_size; 1630 1631 btrfs_info(fs_info, "resize thread pool %d -> %d", 1632 old_pool_size, new_pool_size); 1633 1634 btrfs_workqueue_set_max(fs_info->workers, new_pool_size); 1635 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size); 1636 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size); 1637 workqueue_set_max_active(fs_info->endio_workers, new_pool_size); 1638 workqueue_set_max_active(fs_info->endio_meta_workers, new_pool_size); 1639 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size); 1640 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size); 1641 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size); 1642 } 1643 1644 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info, 1645 unsigned long old_opts, int flags) 1646 { 1647 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1648 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1649 (flags & SB_RDONLY))) { 1650 /* wait for any defraggers to finish */ 1651 wait_event(fs_info->transaction_wait, 1652 (atomic_read(&fs_info->defrag_running) == 0)); 1653 if (flags & SB_RDONLY) 1654 sync_filesystem(fs_info->sb); 1655 } 1656 } 1657 1658 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info, 1659 unsigned long old_opts) 1660 { 1661 const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE); 1662 1663 /* 1664 * We need to cleanup all defragable inodes if the autodefragment is 1665 * close or the filesystem is read only. 1666 */ 1667 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1668 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) { 1669 btrfs_cleanup_defrag_inodes(fs_info); 1670 } 1671 1672 /* If we toggled discard async */ 1673 if (!btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) && 1674 btrfs_test_opt(fs_info, DISCARD_ASYNC)) 1675 btrfs_discard_resume(fs_info); 1676 else if (btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) && 1677 !btrfs_test_opt(fs_info, DISCARD_ASYNC)) 1678 btrfs_discard_cleanup(fs_info); 1679 1680 /* If we toggled space cache */ 1681 if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) 1682 btrfs_set_free_space_cache_v1_active(fs_info, cache_opt); 1683 } 1684 1685 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1686 { 1687 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1688 unsigned old_flags = sb->s_flags; 1689 unsigned long old_opts = fs_info->mount_opt; 1690 unsigned long old_compress_type = fs_info->compress_type; 1691 u64 old_max_inline = fs_info->max_inline; 1692 u32 old_thread_pool_size = fs_info->thread_pool_size; 1693 u32 old_metadata_ratio = fs_info->metadata_ratio; 1694 int ret; 1695 1696 sync_filesystem(sb); 1697 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1698 1699 if (data) { 1700 void *new_sec_opts = NULL; 1701 1702 ret = security_sb_eat_lsm_opts(data, &new_sec_opts); 1703 if (!ret) 1704 ret = security_sb_remount(sb, new_sec_opts); 1705 security_free_mnt_opts(&new_sec_opts); 1706 if (ret) 1707 goto restore; 1708 } 1709 1710 ret = btrfs_parse_options(fs_info, data, *flags); 1711 if (ret) 1712 goto restore; 1713 1714 ret = btrfs_check_features(fs_info, !(*flags & SB_RDONLY)); 1715 if (ret < 0) 1716 goto restore; 1717 1718 btrfs_remount_begin(fs_info, old_opts, *flags); 1719 btrfs_resize_thread_pool(fs_info, 1720 fs_info->thread_pool_size, old_thread_pool_size); 1721 1722 if ((bool)btrfs_test_opt(fs_info, FREE_SPACE_TREE) != 1723 (bool)btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) && 1724 (!sb_rdonly(sb) || (*flags & SB_RDONLY))) { 1725 btrfs_warn(fs_info, 1726 "remount supports changing free space tree only from ro to rw"); 1727 /* Make sure free space cache options match the state on disk */ 1728 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) { 1729 btrfs_set_opt(fs_info->mount_opt, FREE_SPACE_TREE); 1730 btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE); 1731 } 1732 if (btrfs_free_space_cache_v1_active(fs_info)) { 1733 btrfs_clear_opt(fs_info->mount_opt, FREE_SPACE_TREE); 1734 btrfs_set_opt(fs_info->mount_opt, SPACE_CACHE); 1735 } 1736 } 1737 1738 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb)) 1739 goto out; 1740 1741 if (*flags & SB_RDONLY) { 1742 /* 1743 * this also happens on 'umount -rf' or on shutdown, when 1744 * the filesystem is busy. 1745 */ 1746 cancel_work_sync(&fs_info->async_reclaim_work); 1747 cancel_work_sync(&fs_info->async_data_reclaim_work); 1748 1749 btrfs_discard_cleanup(fs_info); 1750 1751 /* wait for the uuid_scan task to finish */ 1752 down(&fs_info->uuid_tree_rescan_sem); 1753 /* avoid complains from lockdep et al. */ 1754 up(&fs_info->uuid_tree_rescan_sem); 1755 1756 btrfs_set_sb_rdonly(sb); 1757 1758 /* 1759 * Setting SB_RDONLY will put the cleaner thread to 1760 * sleep at the next loop if it's already active. 1761 * If it's already asleep, we'll leave unused block 1762 * groups on disk until we're mounted read-write again 1763 * unless we clean them up here. 1764 */ 1765 btrfs_delete_unused_bgs(fs_info); 1766 1767 /* 1768 * The cleaner task could be already running before we set the 1769 * flag BTRFS_FS_STATE_RO (and SB_RDONLY in the superblock). 1770 * We must make sure that after we finish the remount, i.e. after 1771 * we call btrfs_commit_super(), the cleaner can no longer start 1772 * a transaction - either because it was dropping a dead root, 1773 * running delayed iputs or deleting an unused block group (the 1774 * cleaner picked a block group from the list of unused block 1775 * groups before we were able to in the previous call to 1776 * btrfs_delete_unused_bgs()). 1777 */ 1778 wait_on_bit(&fs_info->flags, BTRFS_FS_CLEANER_RUNNING, 1779 TASK_UNINTERRUPTIBLE); 1780 1781 /* 1782 * We've set the superblock to RO mode, so we might have made 1783 * the cleaner task sleep without running all pending delayed 1784 * iputs. Go through all the delayed iputs here, so that if an 1785 * unmount happens without remounting RW we don't end up at 1786 * finishing close_ctree() with a non-empty list of delayed 1787 * iputs. 1788 */ 1789 btrfs_run_delayed_iputs(fs_info); 1790 1791 btrfs_dev_replace_suspend_for_unmount(fs_info); 1792 btrfs_scrub_cancel(fs_info); 1793 btrfs_pause_balance(fs_info); 1794 1795 /* 1796 * Pause the qgroup rescan worker if it is running. We don't want 1797 * it to be still running after we are in RO mode, as after that, 1798 * by the time we unmount, it might have left a transaction open, 1799 * so we would leak the transaction and/or crash. 1800 */ 1801 btrfs_qgroup_wait_for_completion(fs_info, false); 1802 1803 ret = btrfs_commit_super(fs_info); 1804 if (ret) 1805 goto restore; 1806 } else { 1807 if (BTRFS_FS_ERROR(fs_info)) { 1808 btrfs_err(fs_info, 1809 "Remounting read-write after error is not allowed"); 1810 ret = -EINVAL; 1811 goto restore; 1812 } 1813 if (fs_info->fs_devices->rw_devices == 0) { 1814 ret = -EACCES; 1815 goto restore; 1816 } 1817 1818 if (!btrfs_check_rw_degradable(fs_info, NULL)) { 1819 btrfs_warn(fs_info, 1820 "too many missing devices, writable remount is not allowed"); 1821 ret = -EACCES; 1822 goto restore; 1823 } 1824 1825 if (btrfs_super_log_root(fs_info->super_copy) != 0) { 1826 btrfs_warn(fs_info, 1827 "mount required to replay tree-log, cannot remount read-write"); 1828 ret = -EINVAL; 1829 goto restore; 1830 } 1831 1832 /* 1833 * NOTE: when remounting with a change that does writes, don't 1834 * put it anywhere above this point, as we are not sure to be 1835 * safe to write until we pass the above checks. 1836 */ 1837 ret = btrfs_start_pre_rw_mount(fs_info); 1838 if (ret) 1839 goto restore; 1840 1841 btrfs_clear_sb_rdonly(sb); 1842 1843 set_bit(BTRFS_FS_OPEN, &fs_info->flags); 1844 1845 /* 1846 * If we've gone from readonly -> read/write, we need to get 1847 * our sync/async discard lists in the right state. 1848 */ 1849 btrfs_discard_resume(fs_info); 1850 } 1851 out: 1852 /* 1853 * We need to set SB_I_VERSION here otherwise it'll get cleared by VFS, 1854 * since the absence of the flag means it can be toggled off by remount. 1855 */ 1856 *flags |= SB_I_VERSION; 1857 1858 wake_up_process(fs_info->transaction_kthread); 1859 btrfs_remount_cleanup(fs_info, old_opts); 1860 btrfs_clear_oneshot_options(fs_info); 1861 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1862 1863 return 0; 1864 1865 restore: 1866 /* We've hit an error - don't reset SB_RDONLY */ 1867 if (sb_rdonly(sb)) 1868 old_flags |= SB_RDONLY; 1869 if (!(old_flags & SB_RDONLY)) 1870 clear_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state); 1871 sb->s_flags = old_flags; 1872 fs_info->mount_opt = old_opts; 1873 fs_info->compress_type = old_compress_type; 1874 fs_info->max_inline = old_max_inline; 1875 btrfs_resize_thread_pool(fs_info, 1876 old_thread_pool_size, fs_info->thread_pool_size); 1877 fs_info->metadata_ratio = old_metadata_ratio; 1878 btrfs_remount_cleanup(fs_info, old_opts); 1879 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1880 1881 return ret; 1882 } 1883 1884 /* Used to sort the devices by max_avail(descending sort) */ 1885 static int btrfs_cmp_device_free_bytes(const void *a, const void *b) 1886 { 1887 const struct btrfs_device_info *dev_info1 = a; 1888 const struct btrfs_device_info *dev_info2 = b; 1889 1890 if (dev_info1->max_avail > dev_info2->max_avail) 1891 return -1; 1892 else if (dev_info1->max_avail < dev_info2->max_avail) 1893 return 1; 1894 return 0; 1895 } 1896 1897 /* 1898 * sort the devices by max_avail, in which max free extent size of each device 1899 * is stored.(Descending Sort) 1900 */ 1901 static inline void btrfs_descending_sort_devices( 1902 struct btrfs_device_info *devices, 1903 size_t nr_devices) 1904 { 1905 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1906 btrfs_cmp_device_free_bytes, NULL); 1907 } 1908 1909 /* 1910 * The helper to calc the free space on the devices that can be used to store 1911 * file data. 1912 */ 1913 static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info, 1914 u64 *free_bytes) 1915 { 1916 struct btrfs_device_info *devices_info; 1917 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1918 struct btrfs_device *device; 1919 u64 type; 1920 u64 avail_space; 1921 u64 min_stripe_size; 1922 int num_stripes = 1; 1923 int i = 0, nr_devices; 1924 const struct btrfs_raid_attr *rattr; 1925 1926 /* 1927 * We aren't under the device list lock, so this is racy-ish, but good 1928 * enough for our purposes. 1929 */ 1930 nr_devices = fs_info->fs_devices->open_devices; 1931 if (!nr_devices) { 1932 smp_mb(); 1933 nr_devices = fs_info->fs_devices->open_devices; 1934 ASSERT(nr_devices); 1935 if (!nr_devices) { 1936 *free_bytes = 0; 1937 return 0; 1938 } 1939 } 1940 1941 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info), 1942 GFP_KERNEL); 1943 if (!devices_info) 1944 return -ENOMEM; 1945 1946 /* calc min stripe number for data space allocation */ 1947 type = btrfs_data_alloc_profile(fs_info); 1948 rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)]; 1949 1950 if (type & BTRFS_BLOCK_GROUP_RAID0) 1951 num_stripes = nr_devices; 1952 else if (type & BTRFS_BLOCK_GROUP_RAID1_MASK) 1953 num_stripes = rattr->ncopies; 1954 else if (type & BTRFS_BLOCK_GROUP_RAID10) 1955 num_stripes = 4; 1956 1957 /* Adjust for more than 1 stripe per device */ 1958 min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN; 1959 1960 rcu_read_lock(); 1961 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { 1962 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, 1963 &device->dev_state) || 1964 !device->bdev || 1965 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) 1966 continue; 1967 1968 if (i >= nr_devices) 1969 break; 1970 1971 avail_space = device->total_bytes - device->bytes_used; 1972 1973 /* align with stripe_len */ 1974 avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN); 1975 1976 /* 1977 * Ensure we have at least min_stripe_size on top of the 1978 * reserved space on the device. 1979 */ 1980 if (avail_space <= BTRFS_DEVICE_RANGE_RESERVED + min_stripe_size) 1981 continue; 1982 1983 avail_space -= BTRFS_DEVICE_RANGE_RESERVED; 1984 1985 devices_info[i].dev = device; 1986 devices_info[i].max_avail = avail_space; 1987 1988 i++; 1989 } 1990 rcu_read_unlock(); 1991 1992 nr_devices = i; 1993 1994 btrfs_descending_sort_devices(devices_info, nr_devices); 1995 1996 i = nr_devices - 1; 1997 avail_space = 0; 1998 while (nr_devices >= rattr->devs_min) { 1999 num_stripes = min(num_stripes, nr_devices); 2000 2001 if (devices_info[i].max_avail >= min_stripe_size) { 2002 int j; 2003 u64 alloc_size; 2004 2005 avail_space += devices_info[i].max_avail * num_stripes; 2006 alloc_size = devices_info[i].max_avail; 2007 for (j = i + 1 - num_stripes; j <= i; j++) 2008 devices_info[j].max_avail -= alloc_size; 2009 } 2010 i--; 2011 nr_devices--; 2012 } 2013 2014 kfree(devices_info); 2015 *free_bytes = avail_space; 2016 return 0; 2017 } 2018 2019 /* 2020 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles. 2021 * 2022 * If there's a redundant raid level at DATA block groups, use the respective 2023 * multiplier to scale the sizes. 2024 * 2025 * Unused device space usage is based on simulating the chunk allocator 2026 * algorithm that respects the device sizes and order of allocations. This is 2027 * a close approximation of the actual use but there are other factors that may 2028 * change the result (like a new metadata chunk). 2029 * 2030 * If metadata is exhausted, f_bavail will be 0. 2031 */ 2032 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 2033 { 2034 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); 2035 struct btrfs_super_block *disk_super = fs_info->super_copy; 2036 struct btrfs_space_info *found; 2037 u64 total_used = 0; 2038 u64 total_free_data = 0; 2039 u64 total_free_meta = 0; 2040 u32 bits = fs_info->sectorsize_bits; 2041 __be32 *fsid = (__be32 *)fs_info->fs_devices->fsid; 2042 unsigned factor = 1; 2043 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 2044 int ret; 2045 u64 thresh = 0; 2046 int mixed = 0; 2047 2048 list_for_each_entry(found, &fs_info->space_info, list) { 2049 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 2050 int i; 2051 2052 total_free_data += found->disk_total - found->disk_used; 2053 total_free_data -= 2054 btrfs_account_ro_block_groups_free_space(found); 2055 2056 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { 2057 if (!list_empty(&found->block_groups[i])) 2058 factor = btrfs_bg_type_to_factor( 2059 btrfs_raid_array[i].bg_flag); 2060 } 2061 } 2062 2063 /* 2064 * Metadata in mixed block group profiles are accounted in data 2065 */ 2066 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) { 2067 if (found->flags & BTRFS_BLOCK_GROUP_DATA) 2068 mixed = 1; 2069 else 2070 total_free_meta += found->disk_total - 2071 found->disk_used; 2072 } 2073 2074 total_used += found->disk_used; 2075 } 2076 2077 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor); 2078 buf->f_blocks >>= bits; 2079 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits); 2080 2081 /* Account global block reserve as used, it's in logical size already */ 2082 spin_lock(&block_rsv->lock); 2083 /* Mixed block groups accounting is not byte-accurate, avoid overflow */ 2084 if (buf->f_bfree >= block_rsv->size >> bits) 2085 buf->f_bfree -= block_rsv->size >> bits; 2086 else 2087 buf->f_bfree = 0; 2088 spin_unlock(&block_rsv->lock); 2089 2090 buf->f_bavail = div_u64(total_free_data, factor); 2091 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data); 2092 if (ret) 2093 return ret; 2094 buf->f_bavail += div_u64(total_free_data, factor); 2095 buf->f_bavail = buf->f_bavail >> bits; 2096 2097 /* 2098 * We calculate the remaining metadata space minus global reserve. If 2099 * this is (supposedly) smaller than zero, there's no space. But this 2100 * does not hold in practice, the exhausted state happens where's still 2101 * some positive delta. So we apply some guesswork and compare the 2102 * delta to a 4M threshold. (Practically observed delta was ~2M.) 2103 * 2104 * We probably cannot calculate the exact threshold value because this 2105 * depends on the internal reservations requested by various 2106 * operations, so some operations that consume a few metadata will 2107 * succeed even if the Avail is zero. But this is better than the other 2108 * way around. 2109 */ 2110 thresh = SZ_4M; 2111 2112 /* 2113 * We only want to claim there's no available space if we can no longer 2114 * allocate chunks for our metadata profile and our global reserve will 2115 * not fit in the free metadata space. If we aren't ->full then we 2116 * still can allocate chunks and thus are fine using the currently 2117 * calculated f_bavail. 2118 */ 2119 if (!mixed && block_rsv->space_info->full && 2120 (total_free_meta < thresh || total_free_meta - thresh < block_rsv->size)) 2121 buf->f_bavail = 0; 2122 2123 buf->f_type = BTRFS_SUPER_MAGIC; 2124 buf->f_bsize = dentry->d_sb->s_blocksize; 2125 buf->f_namelen = BTRFS_NAME_LEN; 2126 2127 /* We treat it as constant endianness (it doesn't matter _which_) 2128 because we want the fsid to come out the same whether mounted 2129 on a big-endian or little-endian host */ 2130 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 2131 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 2132 /* Mask in the root object ID too, to disambiguate subvols */ 2133 buf->f_fsid.val[0] ^= 2134 BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32; 2135 buf->f_fsid.val[1] ^= 2136 BTRFS_I(d_inode(dentry))->root->root_key.objectid; 2137 2138 return 0; 2139 } 2140 2141 static void btrfs_kill_super(struct super_block *sb) 2142 { 2143 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2144 kill_anon_super(sb); 2145 btrfs_free_fs_info(fs_info); 2146 } 2147 2148 static struct file_system_type btrfs_fs_type = { 2149 .owner = THIS_MODULE, 2150 .name = "btrfs", 2151 .mount = btrfs_mount, 2152 .kill_sb = btrfs_kill_super, 2153 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, 2154 }; 2155 2156 static struct file_system_type btrfs_root_fs_type = { 2157 .owner = THIS_MODULE, 2158 .name = "btrfs", 2159 .mount = btrfs_mount_root, 2160 .kill_sb = btrfs_kill_super, 2161 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_ALLOW_IDMAP, 2162 }; 2163 2164 MODULE_ALIAS_FS("btrfs"); 2165 2166 static int btrfs_control_open(struct inode *inode, struct file *file) 2167 { 2168 /* 2169 * The control file's private_data is used to hold the 2170 * transaction when it is started and is used to keep 2171 * track of whether a transaction is already in progress. 2172 */ 2173 file->private_data = NULL; 2174 return 0; 2175 } 2176 2177 /* 2178 * Used by /dev/btrfs-control for devices ioctls. 2179 */ 2180 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 2181 unsigned long arg) 2182 { 2183 struct btrfs_ioctl_vol_args *vol; 2184 struct btrfs_device *device = NULL; 2185 dev_t devt = 0; 2186 int ret = -ENOTTY; 2187 2188 if (!capable(CAP_SYS_ADMIN)) 2189 return -EPERM; 2190 2191 vol = memdup_user((void __user *)arg, sizeof(*vol)); 2192 if (IS_ERR(vol)) 2193 return PTR_ERR(vol); 2194 vol->name[BTRFS_PATH_NAME_MAX] = '\0'; 2195 2196 switch (cmd) { 2197 case BTRFS_IOC_SCAN_DEV: 2198 mutex_lock(&uuid_mutex); 2199 device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ); 2200 ret = PTR_ERR_OR_ZERO(device); 2201 mutex_unlock(&uuid_mutex); 2202 break; 2203 case BTRFS_IOC_FORGET_DEV: 2204 if (vol->name[0] != 0) { 2205 ret = lookup_bdev(vol->name, &devt); 2206 if (ret) 2207 break; 2208 } 2209 ret = btrfs_forget_devices(devt); 2210 break; 2211 case BTRFS_IOC_DEVICES_READY: 2212 mutex_lock(&uuid_mutex); 2213 device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ); 2214 if (IS_ERR(device)) { 2215 mutex_unlock(&uuid_mutex); 2216 ret = PTR_ERR(device); 2217 break; 2218 } 2219 ret = !(device->fs_devices->num_devices == 2220 device->fs_devices->total_devices); 2221 mutex_unlock(&uuid_mutex); 2222 break; 2223 case BTRFS_IOC_GET_SUPPORTED_FEATURES: 2224 ret = btrfs_ioctl_get_supported_features((void __user*)arg); 2225 break; 2226 } 2227 2228 kfree(vol); 2229 return ret; 2230 } 2231 2232 static int btrfs_freeze(struct super_block *sb) 2233 { 2234 struct btrfs_trans_handle *trans; 2235 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2236 struct btrfs_root *root = fs_info->tree_root; 2237 2238 set_bit(BTRFS_FS_FROZEN, &fs_info->flags); 2239 /* 2240 * We don't need a barrier here, we'll wait for any transaction that 2241 * could be in progress on other threads (and do delayed iputs that 2242 * we want to avoid on a frozen filesystem), or do the commit 2243 * ourselves. 2244 */ 2245 trans = btrfs_attach_transaction_barrier(root); 2246 if (IS_ERR(trans)) { 2247 /* no transaction, don't bother */ 2248 if (PTR_ERR(trans) == -ENOENT) 2249 return 0; 2250 return PTR_ERR(trans); 2251 } 2252 return btrfs_commit_transaction(trans); 2253 } 2254 2255 static int check_dev_super(struct btrfs_device *dev) 2256 { 2257 struct btrfs_fs_info *fs_info = dev->fs_info; 2258 struct btrfs_super_block *sb; 2259 u16 csum_type; 2260 int ret = 0; 2261 2262 /* This should be called with fs still frozen. */ 2263 ASSERT(test_bit(BTRFS_FS_FROZEN, &fs_info->flags)); 2264 2265 /* Missing dev, no need to check. */ 2266 if (!dev->bdev) 2267 return 0; 2268 2269 /* Only need to check the primary super block. */ 2270 sb = btrfs_read_dev_one_super(dev->bdev, 0, true); 2271 if (IS_ERR(sb)) 2272 return PTR_ERR(sb); 2273 2274 /* Verify the checksum. */ 2275 csum_type = btrfs_super_csum_type(sb); 2276 if (csum_type != btrfs_super_csum_type(fs_info->super_copy)) { 2277 btrfs_err(fs_info, "csum type changed, has %u expect %u", 2278 csum_type, btrfs_super_csum_type(fs_info->super_copy)); 2279 ret = -EUCLEAN; 2280 goto out; 2281 } 2282 2283 if (btrfs_check_super_csum(fs_info, sb)) { 2284 btrfs_err(fs_info, "csum for on-disk super block no longer matches"); 2285 ret = -EUCLEAN; 2286 goto out; 2287 } 2288 2289 /* Btrfs_validate_super() includes fsid check against super->fsid. */ 2290 ret = btrfs_validate_super(fs_info, sb, 0); 2291 if (ret < 0) 2292 goto out; 2293 2294 if (btrfs_super_generation(sb) != fs_info->last_trans_committed) { 2295 btrfs_err(fs_info, "transid mismatch, has %llu expect %llu", 2296 btrfs_super_generation(sb), 2297 fs_info->last_trans_committed); 2298 ret = -EUCLEAN; 2299 goto out; 2300 } 2301 out: 2302 btrfs_release_disk_super(sb); 2303 return ret; 2304 } 2305 2306 static int btrfs_unfreeze(struct super_block *sb) 2307 { 2308 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2309 struct btrfs_device *device; 2310 int ret = 0; 2311 2312 /* 2313 * Make sure the fs is not changed by accident (like hibernation then 2314 * modified by other OS). 2315 * If we found anything wrong, we mark the fs error immediately. 2316 * 2317 * And since the fs is frozen, no one can modify the fs yet, thus 2318 * we don't need to hold device_list_mutex. 2319 */ 2320 list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) { 2321 ret = check_dev_super(device); 2322 if (ret < 0) { 2323 btrfs_handle_fs_error(fs_info, ret, 2324 "super block on devid %llu got modified unexpectedly", 2325 device->devid); 2326 break; 2327 } 2328 } 2329 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags); 2330 2331 /* 2332 * We still return 0, to allow VFS layer to unfreeze the fs even the 2333 * above checks failed. Since the fs is either fine or read-only, we're 2334 * safe to continue, without causing further damage. 2335 */ 2336 return 0; 2337 } 2338 2339 static int btrfs_show_devname(struct seq_file *m, struct dentry *root) 2340 { 2341 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); 2342 2343 /* 2344 * There should be always a valid pointer in latest_dev, it may be stale 2345 * for a short moment in case it's being deleted but still valid until 2346 * the end of RCU grace period. 2347 */ 2348 rcu_read_lock(); 2349 seq_escape(m, btrfs_dev_name(fs_info->fs_devices->latest_dev), " \t\n\\"); 2350 rcu_read_unlock(); 2351 2352 return 0; 2353 } 2354 2355 static const struct super_operations btrfs_super_ops = { 2356 .drop_inode = btrfs_drop_inode, 2357 .evict_inode = btrfs_evict_inode, 2358 .put_super = btrfs_put_super, 2359 .sync_fs = btrfs_sync_fs, 2360 .show_options = btrfs_show_options, 2361 .show_devname = btrfs_show_devname, 2362 .alloc_inode = btrfs_alloc_inode, 2363 .destroy_inode = btrfs_destroy_inode, 2364 .free_inode = btrfs_free_inode, 2365 .statfs = btrfs_statfs, 2366 .remount_fs = btrfs_remount, 2367 .freeze_fs = btrfs_freeze, 2368 .unfreeze_fs = btrfs_unfreeze, 2369 }; 2370 2371 static const struct file_operations btrfs_ctl_fops = { 2372 .open = btrfs_control_open, 2373 .unlocked_ioctl = btrfs_control_ioctl, 2374 .compat_ioctl = compat_ptr_ioctl, 2375 .owner = THIS_MODULE, 2376 .llseek = noop_llseek, 2377 }; 2378 2379 static struct miscdevice btrfs_misc = { 2380 .minor = BTRFS_MINOR, 2381 .name = "btrfs-control", 2382 .fops = &btrfs_ctl_fops 2383 }; 2384 2385 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 2386 MODULE_ALIAS("devname:btrfs-control"); 2387 2388 static int __init btrfs_interface_init(void) 2389 { 2390 return misc_register(&btrfs_misc); 2391 } 2392 2393 static __cold void btrfs_interface_exit(void) 2394 { 2395 misc_deregister(&btrfs_misc); 2396 } 2397 2398 static int __init btrfs_print_mod_info(void) 2399 { 2400 static const char options[] = "" 2401 #ifdef CONFIG_BTRFS_DEBUG 2402 ", debug=on" 2403 #endif 2404 #ifdef CONFIG_BTRFS_ASSERT 2405 ", assert=on" 2406 #endif 2407 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 2408 ", integrity-checker=on" 2409 #endif 2410 #ifdef CONFIG_BTRFS_FS_REF_VERIFY 2411 ", ref-verify=on" 2412 #endif 2413 #ifdef CONFIG_BLK_DEV_ZONED 2414 ", zoned=yes" 2415 #else 2416 ", zoned=no" 2417 #endif 2418 #ifdef CONFIG_FS_VERITY 2419 ", fsverity=yes" 2420 #else 2421 ", fsverity=no" 2422 #endif 2423 ; 2424 pr_info("Btrfs loaded%s\n", options); 2425 return 0; 2426 } 2427 2428 static int register_btrfs(void) 2429 { 2430 return register_filesystem(&btrfs_fs_type); 2431 } 2432 2433 static void unregister_btrfs(void) 2434 { 2435 unregister_filesystem(&btrfs_fs_type); 2436 } 2437 2438 /* Helper structure for long init/exit functions. */ 2439 struct init_sequence { 2440 int (*init_func)(void); 2441 /* Can be NULL if the init_func doesn't need cleanup. */ 2442 void (*exit_func)(void); 2443 }; 2444 2445 static const struct init_sequence mod_init_seq[] = { 2446 { 2447 .init_func = btrfs_props_init, 2448 .exit_func = NULL, 2449 }, { 2450 .init_func = btrfs_init_sysfs, 2451 .exit_func = btrfs_exit_sysfs, 2452 }, { 2453 .init_func = btrfs_init_compress, 2454 .exit_func = btrfs_exit_compress, 2455 }, { 2456 .init_func = btrfs_init_cachep, 2457 .exit_func = btrfs_destroy_cachep, 2458 }, { 2459 .init_func = btrfs_transaction_init, 2460 .exit_func = btrfs_transaction_exit, 2461 }, { 2462 .init_func = btrfs_ctree_init, 2463 .exit_func = btrfs_ctree_exit, 2464 }, { 2465 .init_func = btrfs_free_space_init, 2466 .exit_func = btrfs_free_space_exit, 2467 }, { 2468 .init_func = extent_state_init_cachep, 2469 .exit_func = extent_state_free_cachep, 2470 }, { 2471 .init_func = extent_buffer_init_cachep, 2472 .exit_func = extent_buffer_free_cachep, 2473 }, { 2474 .init_func = btrfs_bioset_init, 2475 .exit_func = btrfs_bioset_exit, 2476 }, { 2477 .init_func = extent_map_init, 2478 .exit_func = extent_map_exit, 2479 }, { 2480 .init_func = ordered_data_init, 2481 .exit_func = ordered_data_exit, 2482 }, { 2483 .init_func = btrfs_delayed_inode_init, 2484 .exit_func = btrfs_delayed_inode_exit, 2485 }, { 2486 .init_func = btrfs_auto_defrag_init, 2487 .exit_func = btrfs_auto_defrag_exit, 2488 }, { 2489 .init_func = btrfs_delayed_ref_init, 2490 .exit_func = btrfs_delayed_ref_exit, 2491 }, { 2492 .init_func = btrfs_prelim_ref_init, 2493 .exit_func = btrfs_prelim_ref_exit, 2494 }, { 2495 .init_func = btrfs_interface_init, 2496 .exit_func = btrfs_interface_exit, 2497 }, { 2498 .init_func = btrfs_print_mod_info, 2499 .exit_func = NULL, 2500 }, { 2501 .init_func = btrfs_run_sanity_tests, 2502 .exit_func = NULL, 2503 }, { 2504 .init_func = register_btrfs, 2505 .exit_func = unregister_btrfs, 2506 } 2507 }; 2508 2509 static bool mod_init_result[ARRAY_SIZE(mod_init_seq)]; 2510 2511 static __always_inline void btrfs_exit_btrfs_fs(void) 2512 { 2513 int i; 2514 2515 for (i = ARRAY_SIZE(mod_init_seq) - 1; i >= 0; i--) { 2516 if (!mod_init_result[i]) 2517 continue; 2518 if (mod_init_seq[i].exit_func) 2519 mod_init_seq[i].exit_func(); 2520 mod_init_result[i] = false; 2521 } 2522 } 2523 2524 static void __exit exit_btrfs_fs(void) 2525 { 2526 btrfs_exit_btrfs_fs(); 2527 btrfs_cleanup_fs_uuids(); 2528 } 2529 2530 static int __init init_btrfs_fs(void) 2531 { 2532 int ret; 2533 int i; 2534 2535 for (i = 0; i < ARRAY_SIZE(mod_init_seq); i++) { 2536 ASSERT(!mod_init_result[i]); 2537 ret = mod_init_seq[i].init_func(); 2538 if (ret < 0) { 2539 btrfs_exit_btrfs_fs(); 2540 return ret; 2541 } 2542 mod_init_result[i] = true; 2543 } 2544 return 0; 2545 } 2546 2547 late_initcall(init_btrfs_fs); 2548 module_exit(exit_btrfs_fs) 2549 2550 MODULE_LICENSE("GPL"); 2551 MODULE_SOFTDEP("pre: crc32c"); 2552 MODULE_SOFTDEP("pre: xxhash64"); 2553 MODULE_SOFTDEP("pre: sha256"); 2554 MODULE_SOFTDEP("pre: blake2b-256"); 2555