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