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/cleancache.h> 27 #include <linux/ratelimit.h> 28 #include <linux/crc32c.h> 29 #include <linux/btrfs.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 "volumes.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 #define CREATE_TRACE_POINTS 53 #include <trace/events/btrfs.h> 54 55 static const struct super_operations btrfs_super_ops; 56 57 /* 58 * Types for mounting the default subvolume and a subvolume explicitly 59 * requested by subvol=/path. That way the callchain is straightforward and we 60 * don't have to play tricks with the mount options and recursive calls to 61 * btrfs_mount. 62 * 63 * The new btrfs_root_fs_type also servers as a tag for the bdev_holder. 64 */ 65 static struct file_system_type btrfs_fs_type; 66 static struct file_system_type btrfs_root_fs_type; 67 68 static int btrfs_remount(struct super_block *sb, int *flags, char *data); 69 70 /* 71 * Generally the error codes correspond to their respective errors, but there 72 * are a few special cases. 73 * 74 * EUCLEAN: Any sort of corruption that we encounter. The tree-checker for 75 * instance will return EUCLEAN if any of the blocks are corrupted in 76 * a way that is problematic. We want to reserve EUCLEAN for these 77 * sort of corruptions. 78 * 79 * EROFS: If we check BTRFS_FS_STATE_ERROR and fail out with a return error, we 80 * need to use EROFS for this case. We will have no idea of the 81 * original failure, that will have been reported at the time we tripped 82 * over the error. Each subsequent error that doesn't have any context 83 * of the original error should use EROFS when handling BTRFS_FS_STATE_ERROR. 84 */ 85 const char * __attribute_const__ btrfs_decode_error(int errno) 86 { 87 char *errstr = "unknown"; 88 89 switch (errno) { 90 case -ENOENT: /* -2 */ 91 errstr = "No such entry"; 92 break; 93 case -EIO: /* -5 */ 94 errstr = "IO failure"; 95 break; 96 case -ENOMEM: /* -12*/ 97 errstr = "Out of memory"; 98 break; 99 case -EEXIST: /* -17 */ 100 errstr = "Object already exists"; 101 break; 102 case -ENOSPC: /* -28 */ 103 errstr = "No space left"; 104 break; 105 case -EROFS: /* -30 */ 106 errstr = "Readonly filesystem"; 107 break; 108 case -EOPNOTSUPP: /* -95 */ 109 errstr = "Operation not supported"; 110 break; 111 case -EUCLEAN: /* -117 */ 112 errstr = "Filesystem corrupted"; 113 break; 114 case -EDQUOT: /* -122 */ 115 errstr = "Quota exceeded"; 116 break; 117 } 118 119 return errstr; 120 } 121 122 /* 123 * __btrfs_handle_fs_error decodes expected errors from the caller and 124 * invokes the appropriate error response. 125 */ 126 __cold 127 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function, 128 unsigned int line, int errno, const char *fmt, ...) 129 { 130 struct super_block *sb = fs_info->sb; 131 #ifdef CONFIG_PRINTK 132 const char *errstr; 133 #endif 134 135 /* 136 * Special case: if the error is EROFS, and we're already 137 * under SB_RDONLY, then it is safe here. 138 */ 139 if (errno == -EROFS && sb_rdonly(sb)) 140 return; 141 142 #ifdef CONFIG_PRINTK 143 errstr = btrfs_decode_error(errno); 144 if (fmt) { 145 struct va_format vaf; 146 va_list args; 147 148 va_start(args, fmt); 149 vaf.fmt = fmt; 150 vaf.va = &args; 151 152 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n", 153 sb->s_id, function, line, errno, errstr, &vaf); 154 va_end(args); 155 } else { 156 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n", 157 sb->s_id, function, line, errno, errstr); 158 } 159 #endif 160 161 /* 162 * Today we only save the error info to memory. Long term we'll 163 * also send it down to the disk 164 */ 165 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state); 166 167 /* Don't go through full error handling during mount */ 168 if (!(sb->s_flags & SB_BORN)) 169 return; 170 171 if (sb_rdonly(sb)) 172 return; 173 174 btrfs_discard_stop(fs_info); 175 176 /* btrfs handle error by forcing the filesystem readonly */ 177 btrfs_set_sb_rdonly(sb); 178 btrfs_info(fs_info, "forced readonly"); 179 /* 180 * Note that a running device replace operation is not canceled here 181 * although there is no way to update the progress. It would add the 182 * risk of a deadlock, therefore the canceling is omitted. The only 183 * penalty is that some I/O remains active until the procedure 184 * completes. The next time when the filesystem is mounted writable 185 * again, the device replace operation continues. 186 */ 187 } 188 189 #ifdef CONFIG_PRINTK 190 static const char * const logtypes[] = { 191 "emergency", 192 "alert", 193 "critical", 194 "error", 195 "warning", 196 "notice", 197 "info", 198 "debug", 199 }; 200 201 202 /* 203 * Use one ratelimit state per log level so that a flood of less important 204 * messages doesn't cause more important ones to be dropped. 205 */ 206 static struct ratelimit_state printk_limits[] = { 207 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100), 208 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100), 209 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100), 210 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100), 211 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100), 212 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100), 213 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100), 214 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100), 215 }; 216 217 void __cold btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...) 218 { 219 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0"; 220 struct va_format vaf; 221 va_list args; 222 int kern_level; 223 const char *type = logtypes[4]; 224 struct ratelimit_state *ratelimit = &printk_limits[4]; 225 226 va_start(args, fmt); 227 228 while ((kern_level = printk_get_level(fmt)) != 0) { 229 size_t size = printk_skip_level(fmt) - fmt; 230 231 if (kern_level >= '0' && kern_level <= '7') { 232 memcpy(lvl, fmt, size); 233 lvl[size] = '\0'; 234 type = logtypes[kern_level - '0']; 235 ratelimit = &printk_limits[kern_level - '0']; 236 } 237 fmt += size; 238 } 239 240 vaf.fmt = fmt; 241 vaf.va = &args; 242 243 if (__ratelimit(ratelimit)) { 244 if (fs_info) 245 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, 246 fs_info->sb->s_id, &vaf); 247 else 248 printk("%sBTRFS %s: %pV\n", lvl, type, &vaf); 249 } 250 251 va_end(args); 252 } 253 #endif 254 255 #if BITS_PER_LONG == 32 256 void __cold btrfs_warn_32bit_limit(struct btrfs_fs_info *fs_info) 257 { 258 if (!test_and_set_bit(BTRFS_FS_32BIT_WARN, &fs_info->flags)) { 259 btrfs_warn(fs_info, "reaching 32bit limit for logical addresses"); 260 btrfs_warn(fs_info, 261 "due to page cache limit on 32bit systems, btrfs can't access metadata at or beyond %lluT", 262 BTRFS_32BIT_MAX_FILE_SIZE >> 40); 263 btrfs_warn(fs_info, 264 "please consider upgrading to 64bit kernel/hardware"); 265 } 266 } 267 268 void __cold btrfs_err_32bit_limit(struct btrfs_fs_info *fs_info) 269 { 270 if (!test_and_set_bit(BTRFS_FS_32BIT_ERROR, &fs_info->flags)) { 271 btrfs_err(fs_info, "reached 32bit limit for logical addresses"); 272 btrfs_err(fs_info, 273 "due to page cache limit on 32bit systems, metadata beyond %lluT can't be accessed", 274 BTRFS_32BIT_MAX_FILE_SIZE >> 40); 275 btrfs_err(fs_info, 276 "please consider upgrading to 64bit kernel/hardware"); 277 } 278 } 279 #endif 280 281 /* 282 * We only mark the transaction aborted and then set the file system read-only. 283 * This will prevent new transactions from starting or trying to join this 284 * one. 285 * 286 * This means that error recovery at the call site is limited to freeing 287 * any local memory allocations and passing the error code up without 288 * further cleanup. The transaction should complete as it normally would 289 * in the call path but will return -EIO. 290 * 291 * We'll complete the cleanup in btrfs_end_transaction and 292 * btrfs_commit_transaction. 293 */ 294 __cold 295 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 296 const char *function, 297 unsigned int line, int errno) 298 { 299 struct btrfs_fs_info *fs_info = trans->fs_info; 300 301 WRITE_ONCE(trans->aborted, errno); 302 /* Nothing used. The other threads that have joined this 303 * transaction may be able to continue. */ 304 if (!trans->dirty && list_empty(&trans->new_bgs)) { 305 const char *errstr; 306 307 errstr = btrfs_decode_error(errno); 308 btrfs_warn(fs_info, 309 "%s:%d: Aborting unused transaction(%s).", 310 function, line, errstr); 311 return; 312 } 313 WRITE_ONCE(trans->transaction->aborted, errno); 314 /* Wake up anybody who may be waiting on this transaction */ 315 wake_up(&fs_info->transaction_wait); 316 wake_up(&fs_info->transaction_blocked_wait); 317 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL); 318 } 319 /* 320 * __btrfs_panic decodes unexpected, fatal errors from the caller, 321 * issues an alert, and either panics or BUGs, depending on mount options. 322 */ 323 __cold 324 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, 325 unsigned int line, int errno, const char *fmt, ...) 326 { 327 char *s_id = "<unknown>"; 328 const char *errstr; 329 struct va_format vaf = { .fmt = fmt }; 330 va_list args; 331 332 if (fs_info) 333 s_id = fs_info->sb->s_id; 334 335 va_start(args, fmt); 336 vaf.va = &args; 337 338 errstr = btrfs_decode_error(errno); 339 if (fs_info && (btrfs_test_opt(fs_info, PANIC_ON_FATAL_ERROR))) 340 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n", 341 s_id, function, line, &vaf, errno, errstr); 342 343 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)", 344 function, line, &vaf, errno, errstr); 345 va_end(args); 346 /* Caller calls BUG() */ 347 } 348 349 static void btrfs_put_super(struct super_block *sb) 350 { 351 close_ctree(btrfs_sb(sb)); 352 } 353 354 enum { 355 Opt_acl, Opt_noacl, 356 Opt_clear_cache, 357 Opt_commit_interval, 358 Opt_compress, 359 Opt_compress_force, 360 Opt_compress_force_type, 361 Opt_compress_type, 362 Opt_degraded, 363 Opt_device, 364 Opt_fatal_errors, 365 Opt_flushoncommit, Opt_noflushoncommit, 366 Opt_max_inline, 367 Opt_barrier, Opt_nobarrier, 368 Opt_datacow, Opt_nodatacow, 369 Opt_datasum, Opt_nodatasum, 370 Opt_defrag, Opt_nodefrag, 371 Opt_discard, Opt_nodiscard, 372 Opt_discard_mode, 373 Opt_norecovery, 374 Opt_ratio, 375 Opt_rescan_uuid_tree, 376 Opt_skip_balance, 377 Opt_space_cache, Opt_no_space_cache, 378 Opt_space_cache_version, 379 Opt_ssd, Opt_nossd, 380 Opt_ssd_spread, Opt_nossd_spread, 381 Opt_subvol, 382 Opt_subvol_empty, 383 Opt_subvolid, 384 Opt_thread_pool, 385 Opt_treelog, Opt_notreelog, 386 Opt_user_subvol_rm_allowed, 387 388 /* Rescue options */ 389 Opt_rescue, 390 Opt_usebackuproot, 391 Opt_nologreplay, 392 Opt_ignorebadroots, 393 Opt_ignoredatacsums, 394 Opt_rescue_all, 395 396 /* Deprecated options */ 397 Opt_recovery, 398 Opt_inode_cache, Opt_noinode_cache, 399 400 /* Debugging options */ 401 Opt_check_integrity, 402 Opt_check_integrity_including_extent_data, 403 Opt_check_integrity_print_mask, 404 Opt_enospc_debug, Opt_noenospc_debug, 405 #ifdef CONFIG_BTRFS_DEBUG 406 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all, 407 #endif 408 #ifdef CONFIG_BTRFS_FS_REF_VERIFY 409 Opt_ref_verify, 410 #endif 411 Opt_err, 412 }; 413 414 static const match_table_t tokens = { 415 {Opt_acl, "acl"}, 416 {Opt_noacl, "noacl"}, 417 {Opt_clear_cache, "clear_cache"}, 418 {Opt_commit_interval, "commit=%u"}, 419 {Opt_compress, "compress"}, 420 {Opt_compress_type, "compress=%s"}, 421 {Opt_compress_force, "compress-force"}, 422 {Opt_compress_force_type, "compress-force=%s"}, 423 {Opt_degraded, "degraded"}, 424 {Opt_device, "device=%s"}, 425 {Opt_fatal_errors, "fatal_errors=%s"}, 426 {Opt_flushoncommit, "flushoncommit"}, 427 {Opt_noflushoncommit, "noflushoncommit"}, 428 {Opt_inode_cache, "inode_cache"}, 429 {Opt_noinode_cache, "noinode_cache"}, 430 {Opt_max_inline, "max_inline=%s"}, 431 {Opt_barrier, "barrier"}, 432 {Opt_nobarrier, "nobarrier"}, 433 {Opt_datacow, "datacow"}, 434 {Opt_nodatacow, "nodatacow"}, 435 {Opt_datasum, "datasum"}, 436 {Opt_nodatasum, "nodatasum"}, 437 {Opt_defrag, "autodefrag"}, 438 {Opt_nodefrag, "noautodefrag"}, 439 {Opt_discard, "discard"}, 440 {Opt_discard_mode, "discard=%s"}, 441 {Opt_nodiscard, "nodiscard"}, 442 {Opt_norecovery, "norecovery"}, 443 {Opt_ratio, "metadata_ratio=%u"}, 444 {Opt_rescan_uuid_tree, "rescan_uuid_tree"}, 445 {Opt_skip_balance, "skip_balance"}, 446 {Opt_space_cache, "space_cache"}, 447 {Opt_no_space_cache, "nospace_cache"}, 448 {Opt_space_cache_version, "space_cache=%s"}, 449 {Opt_ssd, "ssd"}, 450 {Opt_nossd, "nossd"}, 451 {Opt_ssd_spread, "ssd_spread"}, 452 {Opt_nossd_spread, "nossd_spread"}, 453 {Opt_subvol, "subvol=%s"}, 454 {Opt_subvol_empty, "subvol="}, 455 {Opt_subvolid, "subvolid=%s"}, 456 {Opt_thread_pool, "thread_pool=%u"}, 457 {Opt_treelog, "treelog"}, 458 {Opt_notreelog, "notreelog"}, 459 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, 460 461 /* Rescue options */ 462 {Opt_rescue, "rescue=%s"}, 463 /* Deprecated, with alias rescue=nologreplay */ 464 {Opt_nologreplay, "nologreplay"}, 465 /* Deprecated, with alias rescue=usebackuproot */ 466 {Opt_usebackuproot, "usebackuproot"}, 467 468 /* Deprecated options */ 469 {Opt_recovery, "recovery"}, 470 471 /* Debugging options */ 472 {Opt_check_integrity, "check_int"}, 473 {Opt_check_integrity_including_extent_data, "check_int_data"}, 474 {Opt_check_integrity_print_mask, "check_int_print_mask=%u"}, 475 {Opt_enospc_debug, "enospc_debug"}, 476 {Opt_noenospc_debug, "noenospc_debug"}, 477 #ifdef CONFIG_BTRFS_DEBUG 478 {Opt_fragment_data, "fragment=data"}, 479 {Opt_fragment_metadata, "fragment=metadata"}, 480 {Opt_fragment_all, "fragment=all"}, 481 #endif 482 #ifdef CONFIG_BTRFS_FS_REF_VERIFY 483 {Opt_ref_verify, "ref_verify"}, 484 #endif 485 {Opt_err, NULL}, 486 }; 487 488 static const match_table_t rescue_tokens = { 489 {Opt_usebackuproot, "usebackuproot"}, 490 {Opt_nologreplay, "nologreplay"}, 491 {Opt_ignorebadroots, "ignorebadroots"}, 492 {Opt_ignorebadroots, "ibadroots"}, 493 {Opt_ignoredatacsums, "ignoredatacsums"}, 494 {Opt_ignoredatacsums, "idatacsums"}, 495 {Opt_rescue_all, "all"}, 496 {Opt_err, NULL}, 497 }; 498 499 static bool check_ro_option(struct btrfs_fs_info *fs_info, unsigned long opt, 500 const char *opt_name) 501 { 502 if (fs_info->mount_opt & opt) { 503 btrfs_err(fs_info, "%s must be used with ro mount option", 504 opt_name); 505 return true; 506 } 507 return false; 508 } 509 510 static int parse_rescue_options(struct btrfs_fs_info *info, const char *options) 511 { 512 char *opts; 513 char *orig; 514 char *p; 515 substring_t args[MAX_OPT_ARGS]; 516 int ret = 0; 517 518 opts = kstrdup(options, GFP_KERNEL); 519 if (!opts) 520 return -ENOMEM; 521 orig = opts; 522 523 while ((p = strsep(&opts, ":")) != NULL) { 524 int token; 525 526 if (!*p) 527 continue; 528 token = match_token(p, rescue_tokens, args); 529 switch (token){ 530 case Opt_usebackuproot: 531 btrfs_info(info, 532 "trying to use backup root at mount time"); 533 btrfs_set_opt(info->mount_opt, USEBACKUPROOT); 534 break; 535 case Opt_nologreplay: 536 btrfs_set_and_info(info, NOLOGREPLAY, 537 "disabling log replay at mount time"); 538 break; 539 case Opt_ignorebadroots: 540 btrfs_set_and_info(info, IGNOREBADROOTS, 541 "ignoring bad roots"); 542 break; 543 case Opt_ignoredatacsums: 544 btrfs_set_and_info(info, IGNOREDATACSUMS, 545 "ignoring data csums"); 546 break; 547 case Opt_rescue_all: 548 btrfs_info(info, "enabling all of the rescue options"); 549 btrfs_set_and_info(info, IGNOREDATACSUMS, 550 "ignoring data csums"); 551 btrfs_set_and_info(info, IGNOREBADROOTS, 552 "ignoring bad roots"); 553 btrfs_set_and_info(info, NOLOGREPLAY, 554 "disabling log replay at mount time"); 555 break; 556 case Opt_err: 557 btrfs_info(info, "unrecognized rescue option '%s'", p); 558 ret = -EINVAL; 559 goto out; 560 default: 561 break; 562 } 563 564 } 565 out: 566 kfree(orig); 567 return ret; 568 } 569 570 /* 571 * Regular mount options parser. Everything that is needed only when 572 * reading in a new superblock is parsed here. 573 * XXX JDM: This needs to be cleaned up for remount. 574 */ 575 int btrfs_parse_options(struct btrfs_fs_info *info, char *options, 576 unsigned long new_flags) 577 { 578 substring_t args[MAX_OPT_ARGS]; 579 char *p, *num; 580 int intarg; 581 int ret = 0; 582 char *compress_type; 583 bool compress_force = false; 584 enum btrfs_compression_type saved_compress_type; 585 int saved_compress_level; 586 bool saved_compress_force; 587 int no_compress = 0; 588 589 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE)) 590 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE); 591 else if (btrfs_free_space_cache_v1_active(info)) { 592 if (btrfs_is_zoned(info)) { 593 btrfs_info(info, 594 "zoned: clearing existing space cache"); 595 btrfs_set_super_cache_generation(info->super_copy, 0); 596 } else { 597 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 598 } 599 } 600 601 /* 602 * Even the options are empty, we still need to do extra check 603 * against new flags 604 */ 605 if (!options) 606 goto check; 607 608 while ((p = strsep(&options, ",")) != NULL) { 609 int token; 610 if (!*p) 611 continue; 612 613 token = match_token(p, tokens, args); 614 switch (token) { 615 case Opt_degraded: 616 btrfs_info(info, "allowing degraded mounts"); 617 btrfs_set_opt(info->mount_opt, DEGRADED); 618 break; 619 case Opt_subvol: 620 case Opt_subvol_empty: 621 case Opt_subvolid: 622 case Opt_device: 623 /* 624 * These are parsed by btrfs_parse_subvol_options or 625 * btrfs_parse_device_options and can be ignored here. 626 */ 627 break; 628 case Opt_nodatasum: 629 btrfs_set_and_info(info, NODATASUM, 630 "setting nodatasum"); 631 break; 632 case Opt_datasum: 633 if (btrfs_test_opt(info, NODATASUM)) { 634 if (btrfs_test_opt(info, NODATACOW)) 635 btrfs_info(info, 636 "setting datasum, datacow enabled"); 637 else 638 btrfs_info(info, "setting datasum"); 639 } 640 btrfs_clear_opt(info->mount_opt, NODATACOW); 641 btrfs_clear_opt(info->mount_opt, NODATASUM); 642 break; 643 case Opt_nodatacow: 644 if (!btrfs_test_opt(info, NODATACOW)) { 645 if (!btrfs_test_opt(info, COMPRESS) || 646 !btrfs_test_opt(info, FORCE_COMPRESS)) { 647 btrfs_info(info, 648 "setting nodatacow, compression disabled"); 649 } else { 650 btrfs_info(info, "setting nodatacow"); 651 } 652 } 653 btrfs_clear_opt(info->mount_opt, COMPRESS); 654 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 655 btrfs_set_opt(info->mount_opt, NODATACOW); 656 btrfs_set_opt(info->mount_opt, NODATASUM); 657 break; 658 case Opt_datacow: 659 btrfs_clear_and_info(info, NODATACOW, 660 "setting datacow"); 661 break; 662 case Opt_compress_force: 663 case Opt_compress_force_type: 664 compress_force = true; 665 fallthrough; 666 case Opt_compress: 667 case Opt_compress_type: 668 saved_compress_type = btrfs_test_opt(info, 669 COMPRESS) ? 670 info->compress_type : BTRFS_COMPRESS_NONE; 671 saved_compress_force = 672 btrfs_test_opt(info, FORCE_COMPRESS); 673 saved_compress_level = info->compress_level; 674 if (token == Opt_compress || 675 token == Opt_compress_force || 676 strncmp(args[0].from, "zlib", 4) == 0) { 677 compress_type = "zlib"; 678 679 info->compress_type = BTRFS_COMPRESS_ZLIB; 680 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL; 681 /* 682 * args[0] contains uninitialized data since 683 * for these tokens we don't expect any 684 * parameter. 685 */ 686 if (token != Opt_compress && 687 token != Opt_compress_force) 688 info->compress_level = 689 btrfs_compress_str2level( 690 BTRFS_COMPRESS_ZLIB, 691 args[0].from + 4); 692 btrfs_set_opt(info->mount_opt, COMPRESS); 693 btrfs_clear_opt(info->mount_opt, NODATACOW); 694 btrfs_clear_opt(info->mount_opt, NODATASUM); 695 no_compress = 0; 696 } else if (strncmp(args[0].from, "lzo", 3) == 0) { 697 compress_type = "lzo"; 698 info->compress_type = BTRFS_COMPRESS_LZO; 699 info->compress_level = 0; 700 btrfs_set_opt(info->mount_opt, COMPRESS); 701 btrfs_clear_opt(info->mount_opt, NODATACOW); 702 btrfs_clear_opt(info->mount_opt, NODATASUM); 703 btrfs_set_fs_incompat(info, COMPRESS_LZO); 704 no_compress = 0; 705 } else if (strncmp(args[0].from, "zstd", 4) == 0) { 706 compress_type = "zstd"; 707 info->compress_type = BTRFS_COMPRESS_ZSTD; 708 info->compress_level = 709 btrfs_compress_str2level( 710 BTRFS_COMPRESS_ZSTD, 711 args[0].from + 4); 712 btrfs_set_opt(info->mount_opt, COMPRESS); 713 btrfs_clear_opt(info->mount_opt, NODATACOW); 714 btrfs_clear_opt(info->mount_opt, NODATASUM); 715 btrfs_set_fs_incompat(info, COMPRESS_ZSTD); 716 no_compress = 0; 717 } else if (strncmp(args[0].from, "no", 2) == 0) { 718 compress_type = "no"; 719 info->compress_level = 0; 720 info->compress_type = 0; 721 btrfs_clear_opt(info->mount_opt, COMPRESS); 722 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 723 compress_force = false; 724 no_compress++; 725 } else { 726 ret = -EINVAL; 727 goto out; 728 } 729 730 if (compress_force) { 731 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); 732 } else { 733 /* 734 * If we remount from compress-force=xxx to 735 * compress=xxx, we need clear FORCE_COMPRESS 736 * flag, otherwise, there is no way for users 737 * to disable forcible compression separately. 738 */ 739 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 740 } 741 if (no_compress == 1) { 742 btrfs_info(info, "use no compression"); 743 } else if ((info->compress_type != saved_compress_type) || 744 (compress_force != saved_compress_force) || 745 (info->compress_level != saved_compress_level)) { 746 btrfs_info(info, "%s %s compression, level %d", 747 (compress_force) ? "force" : "use", 748 compress_type, info->compress_level); 749 } 750 compress_force = false; 751 break; 752 case Opt_ssd: 753 btrfs_set_and_info(info, SSD, 754 "enabling ssd optimizations"); 755 btrfs_clear_opt(info->mount_opt, NOSSD); 756 break; 757 case Opt_ssd_spread: 758 btrfs_set_and_info(info, SSD, 759 "enabling ssd optimizations"); 760 btrfs_set_and_info(info, SSD_SPREAD, 761 "using spread ssd allocation scheme"); 762 btrfs_clear_opt(info->mount_opt, NOSSD); 763 break; 764 case Opt_nossd: 765 btrfs_set_opt(info->mount_opt, NOSSD); 766 btrfs_clear_and_info(info, SSD, 767 "not using ssd optimizations"); 768 fallthrough; 769 case Opt_nossd_spread: 770 btrfs_clear_and_info(info, SSD_SPREAD, 771 "not using spread ssd allocation scheme"); 772 break; 773 case Opt_barrier: 774 btrfs_clear_and_info(info, NOBARRIER, 775 "turning on barriers"); 776 break; 777 case Opt_nobarrier: 778 btrfs_set_and_info(info, NOBARRIER, 779 "turning off barriers"); 780 break; 781 case Opt_thread_pool: 782 ret = match_int(&args[0], &intarg); 783 if (ret) { 784 goto out; 785 } else if (intarg == 0) { 786 ret = -EINVAL; 787 goto out; 788 } 789 info->thread_pool_size = intarg; 790 break; 791 case Opt_max_inline: 792 num = match_strdup(&args[0]); 793 if (num) { 794 info->max_inline = memparse(num, NULL); 795 kfree(num); 796 797 if (info->max_inline) { 798 info->max_inline = min_t(u64, 799 info->max_inline, 800 info->sectorsize); 801 } 802 btrfs_info(info, "max_inline at %llu", 803 info->max_inline); 804 } else { 805 ret = -ENOMEM; 806 goto out; 807 } 808 break; 809 case Opt_acl: 810 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 811 info->sb->s_flags |= SB_POSIXACL; 812 break; 813 #else 814 btrfs_err(info, "support for ACL not compiled in!"); 815 ret = -EINVAL; 816 goto out; 817 #endif 818 case Opt_noacl: 819 info->sb->s_flags &= ~SB_POSIXACL; 820 break; 821 case Opt_notreelog: 822 btrfs_set_and_info(info, NOTREELOG, 823 "disabling tree log"); 824 break; 825 case Opt_treelog: 826 btrfs_clear_and_info(info, NOTREELOG, 827 "enabling tree log"); 828 break; 829 case Opt_norecovery: 830 case Opt_nologreplay: 831 btrfs_warn(info, 832 "'nologreplay' is deprecated, use 'rescue=nologreplay' instead"); 833 btrfs_set_and_info(info, NOLOGREPLAY, 834 "disabling log replay at mount time"); 835 break; 836 case Opt_flushoncommit: 837 btrfs_set_and_info(info, FLUSHONCOMMIT, 838 "turning on flush-on-commit"); 839 break; 840 case Opt_noflushoncommit: 841 btrfs_clear_and_info(info, FLUSHONCOMMIT, 842 "turning off flush-on-commit"); 843 break; 844 case Opt_ratio: 845 ret = match_int(&args[0], &intarg); 846 if (ret) 847 goto out; 848 info->metadata_ratio = intarg; 849 btrfs_info(info, "metadata ratio %u", 850 info->metadata_ratio); 851 break; 852 case Opt_discard: 853 case Opt_discard_mode: 854 if (token == Opt_discard || 855 strcmp(args[0].from, "sync") == 0) { 856 btrfs_clear_opt(info->mount_opt, DISCARD_ASYNC); 857 btrfs_set_and_info(info, DISCARD_SYNC, 858 "turning on sync discard"); 859 } else if (strcmp(args[0].from, "async") == 0) { 860 btrfs_clear_opt(info->mount_opt, DISCARD_SYNC); 861 btrfs_set_and_info(info, DISCARD_ASYNC, 862 "turning on async discard"); 863 } else { 864 ret = -EINVAL; 865 goto out; 866 } 867 break; 868 case Opt_nodiscard: 869 btrfs_clear_and_info(info, DISCARD_SYNC, 870 "turning off discard"); 871 btrfs_clear_and_info(info, DISCARD_ASYNC, 872 "turning off async discard"); 873 break; 874 case Opt_space_cache: 875 case Opt_space_cache_version: 876 if (token == Opt_space_cache || 877 strcmp(args[0].from, "v1") == 0) { 878 btrfs_clear_opt(info->mount_opt, 879 FREE_SPACE_TREE); 880 btrfs_set_and_info(info, SPACE_CACHE, 881 "enabling disk space caching"); 882 } else if (strcmp(args[0].from, "v2") == 0) { 883 btrfs_clear_opt(info->mount_opt, 884 SPACE_CACHE); 885 btrfs_set_and_info(info, FREE_SPACE_TREE, 886 "enabling free space tree"); 887 } else { 888 ret = -EINVAL; 889 goto out; 890 } 891 break; 892 case Opt_rescan_uuid_tree: 893 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE); 894 break; 895 case Opt_no_space_cache: 896 if (btrfs_test_opt(info, SPACE_CACHE)) { 897 btrfs_clear_and_info(info, SPACE_CACHE, 898 "disabling disk space caching"); 899 } 900 if (btrfs_test_opt(info, FREE_SPACE_TREE)) { 901 btrfs_clear_and_info(info, FREE_SPACE_TREE, 902 "disabling free space tree"); 903 } 904 break; 905 case Opt_inode_cache: 906 case Opt_noinode_cache: 907 btrfs_warn(info, 908 "the 'inode_cache' option is deprecated and has no effect since 5.11"); 909 break; 910 case Opt_clear_cache: 911 btrfs_set_and_info(info, CLEAR_CACHE, 912 "force clearing of disk cache"); 913 break; 914 case Opt_user_subvol_rm_allowed: 915 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 916 break; 917 case Opt_enospc_debug: 918 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 919 break; 920 case Opt_noenospc_debug: 921 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG); 922 break; 923 case Opt_defrag: 924 btrfs_set_and_info(info, AUTO_DEFRAG, 925 "enabling auto defrag"); 926 break; 927 case Opt_nodefrag: 928 btrfs_clear_and_info(info, AUTO_DEFRAG, 929 "disabling auto defrag"); 930 break; 931 case Opt_recovery: 932 case Opt_usebackuproot: 933 btrfs_warn(info, 934 "'%s' is deprecated, use 'rescue=usebackuproot' instead", 935 token == Opt_recovery ? "recovery" : 936 "usebackuproot"); 937 btrfs_info(info, 938 "trying to use backup root at mount time"); 939 btrfs_set_opt(info->mount_opt, USEBACKUPROOT); 940 break; 941 case Opt_skip_balance: 942 btrfs_set_opt(info->mount_opt, SKIP_BALANCE); 943 break; 944 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 945 case Opt_check_integrity_including_extent_data: 946 btrfs_info(info, 947 "enabling check integrity including extent data"); 948 btrfs_set_opt(info->mount_opt, 949 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); 950 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 951 break; 952 case Opt_check_integrity: 953 btrfs_info(info, "enabling check integrity"); 954 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 955 break; 956 case Opt_check_integrity_print_mask: 957 ret = match_int(&args[0], &intarg); 958 if (ret) 959 goto out; 960 info->check_integrity_print_mask = intarg; 961 btrfs_info(info, "check_integrity_print_mask 0x%x", 962 info->check_integrity_print_mask); 963 break; 964 #else 965 case Opt_check_integrity_including_extent_data: 966 case Opt_check_integrity: 967 case Opt_check_integrity_print_mask: 968 btrfs_err(info, 969 "support for check_integrity* not compiled in!"); 970 ret = -EINVAL; 971 goto out; 972 #endif 973 case Opt_fatal_errors: 974 if (strcmp(args[0].from, "panic") == 0) 975 btrfs_set_opt(info->mount_opt, 976 PANIC_ON_FATAL_ERROR); 977 else if (strcmp(args[0].from, "bug") == 0) 978 btrfs_clear_opt(info->mount_opt, 979 PANIC_ON_FATAL_ERROR); 980 else { 981 ret = -EINVAL; 982 goto out; 983 } 984 break; 985 case Opt_commit_interval: 986 intarg = 0; 987 ret = match_int(&args[0], &intarg); 988 if (ret) 989 goto out; 990 if (intarg == 0) { 991 btrfs_info(info, 992 "using default commit interval %us", 993 BTRFS_DEFAULT_COMMIT_INTERVAL); 994 intarg = BTRFS_DEFAULT_COMMIT_INTERVAL; 995 } else if (intarg > 300) { 996 btrfs_warn(info, "excessive commit interval %d", 997 intarg); 998 } 999 info->commit_interval = intarg; 1000 break; 1001 case Opt_rescue: 1002 ret = parse_rescue_options(info, args[0].from); 1003 if (ret < 0) 1004 goto out; 1005 break; 1006 #ifdef CONFIG_BTRFS_DEBUG 1007 case Opt_fragment_all: 1008 btrfs_info(info, "fragmenting all space"); 1009 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 1010 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA); 1011 break; 1012 case Opt_fragment_metadata: 1013 btrfs_info(info, "fragmenting metadata"); 1014 btrfs_set_opt(info->mount_opt, 1015 FRAGMENT_METADATA); 1016 break; 1017 case Opt_fragment_data: 1018 btrfs_info(info, "fragmenting data"); 1019 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 1020 break; 1021 #endif 1022 #ifdef CONFIG_BTRFS_FS_REF_VERIFY 1023 case Opt_ref_verify: 1024 btrfs_info(info, "doing ref verification"); 1025 btrfs_set_opt(info->mount_opt, REF_VERIFY); 1026 break; 1027 #endif 1028 case Opt_err: 1029 btrfs_err(info, "unrecognized mount option '%s'", p); 1030 ret = -EINVAL; 1031 goto out; 1032 default: 1033 break; 1034 } 1035 } 1036 check: 1037 /* We're read-only, don't have to check. */ 1038 if (new_flags & SB_RDONLY) 1039 goto out; 1040 1041 if (check_ro_option(info, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") || 1042 check_ro_option(info, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") || 1043 check_ro_option(info, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums")) 1044 ret = -EINVAL; 1045 out: 1046 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) && 1047 !btrfs_test_opt(info, FREE_SPACE_TREE) && 1048 !btrfs_test_opt(info, CLEAR_CACHE)) { 1049 btrfs_err(info, "cannot disable free space tree"); 1050 ret = -EINVAL; 1051 1052 } 1053 if (!ret) 1054 ret = btrfs_check_mountopts_zoned(info); 1055 if (!ret && btrfs_test_opt(info, SPACE_CACHE)) 1056 btrfs_info(info, "disk space caching is enabled"); 1057 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE)) 1058 btrfs_info(info, "using free space tree"); 1059 return ret; 1060 } 1061 1062 /* 1063 * Parse mount options that are required early in the mount process. 1064 * 1065 * All other options will be parsed on much later in the mount process and 1066 * only when we need to allocate a new super block. 1067 */ 1068 static int btrfs_parse_device_options(const char *options, fmode_t flags, 1069 void *holder) 1070 { 1071 substring_t args[MAX_OPT_ARGS]; 1072 char *device_name, *opts, *orig, *p; 1073 struct btrfs_device *device = NULL; 1074 int error = 0; 1075 1076 lockdep_assert_held(&uuid_mutex); 1077 1078 if (!options) 1079 return 0; 1080 1081 /* 1082 * strsep changes the string, duplicate it because btrfs_parse_options 1083 * gets called later 1084 */ 1085 opts = kstrdup(options, GFP_KERNEL); 1086 if (!opts) 1087 return -ENOMEM; 1088 orig = opts; 1089 1090 while ((p = strsep(&opts, ",")) != NULL) { 1091 int token; 1092 1093 if (!*p) 1094 continue; 1095 1096 token = match_token(p, tokens, args); 1097 if (token == Opt_device) { 1098 device_name = match_strdup(&args[0]); 1099 if (!device_name) { 1100 error = -ENOMEM; 1101 goto out; 1102 } 1103 device = btrfs_scan_one_device(device_name, flags, 1104 holder); 1105 kfree(device_name); 1106 if (IS_ERR(device)) { 1107 error = PTR_ERR(device); 1108 goto out; 1109 } 1110 } 1111 } 1112 1113 out: 1114 kfree(orig); 1115 return error; 1116 } 1117 1118 /* 1119 * Parse mount options that are related to subvolume id 1120 * 1121 * The value is later passed to mount_subvol() 1122 */ 1123 static int btrfs_parse_subvol_options(const char *options, char **subvol_name, 1124 u64 *subvol_objectid) 1125 { 1126 substring_t args[MAX_OPT_ARGS]; 1127 char *opts, *orig, *p; 1128 int error = 0; 1129 u64 subvolid; 1130 1131 if (!options) 1132 return 0; 1133 1134 /* 1135 * strsep changes the string, duplicate it because 1136 * btrfs_parse_device_options gets called later 1137 */ 1138 opts = kstrdup(options, GFP_KERNEL); 1139 if (!opts) 1140 return -ENOMEM; 1141 orig = opts; 1142 1143 while ((p = strsep(&opts, ",")) != NULL) { 1144 int token; 1145 if (!*p) 1146 continue; 1147 1148 token = match_token(p, tokens, args); 1149 switch (token) { 1150 case Opt_subvol: 1151 kfree(*subvol_name); 1152 *subvol_name = match_strdup(&args[0]); 1153 if (!*subvol_name) { 1154 error = -ENOMEM; 1155 goto out; 1156 } 1157 break; 1158 case Opt_subvolid: 1159 error = match_u64(&args[0], &subvolid); 1160 if (error) 1161 goto out; 1162 1163 /* we want the original fs_tree */ 1164 if (subvolid == 0) 1165 subvolid = BTRFS_FS_TREE_OBJECTID; 1166 1167 *subvol_objectid = subvolid; 1168 break; 1169 default: 1170 break; 1171 } 1172 } 1173 1174 out: 1175 kfree(orig); 1176 return error; 1177 } 1178 1179 char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, 1180 u64 subvol_objectid) 1181 { 1182 struct btrfs_root *root = fs_info->tree_root; 1183 struct btrfs_root *fs_root = NULL; 1184 struct btrfs_root_ref *root_ref; 1185 struct btrfs_inode_ref *inode_ref; 1186 struct btrfs_key key; 1187 struct btrfs_path *path = NULL; 1188 char *name = NULL, *ptr; 1189 u64 dirid; 1190 int len; 1191 int ret; 1192 1193 path = btrfs_alloc_path(); 1194 if (!path) { 1195 ret = -ENOMEM; 1196 goto err; 1197 } 1198 1199 name = kmalloc(PATH_MAX, GFP_KERNEL); 1200 if (!name) { 1201 ret = -ENOMEM; 1202 goto err; 1203 } 1204 ptr = name + PATH_MAX - 1; 1205 ptr[0] = '\0'; 1206 1207 /* 1208 * Walk up the subvolume trees in the tree of tree roots by root 1209 * backrefs until we hit the top-level subvolume. 1210 */ 1211 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) { 1212 key.objectid = subvol_objectid; 1213 key.type = BTRFS_ROOT_BACKREF_KEY; 1214 key.offset = (u64)-1; 1215 1216 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 1217 if (ret < 0) { 1218 goto err; 1219 } else if (ret > 0) { 1220 ret = btrfs_previous_item(root, path, subvol_objectid, 1221 BTRFS_ROOT_BACKREF_KEY); 1222 if (ret < 0) { 1223 goto err; 1224 } else if (ret > 0) { 1225 ret = -ENOENT; 1226 goto err; 1227 } 1228 } 1229 1230 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 1231 subvol_objectid = key.offset; 1232 1233 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 1234 struct btrfs_root_ref); 1235 len = btrfs_root_ref_name_len(path->nodes[0], root_ref); 1236 ptr -= len + 1; 1237 if (ptr < name) { 1238 ret = -ENAMETOOLONG; 1239 goto err; 1240 } 1241 read_extent_buffer(path->nodes[0], ptr + 1, 1242 (unsigned long)(root_ref + 1), len); 1243 ptr[0] = '/'; 1244 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref); 1245 btrfs_release_path(path); 1246 1247 fs_root = btrfs_get_fs_root(fs_info, subvol_objectid, true); 1248 if (IS_ERR(fs_root)) { 1249 ret = PTR_ERR(fs_root); 1250 fs_root = NULL; 1251 goto err; 1252 } 1253 1254 /* 1255 * Walk up the filesystem tree by inode refs until we hit the 1256 * root directory. 1257 */ 1258 while (dirid != BTRFS_FIRST_FREE_OBJECTID) { 1259 key.objectid = dirid; 1260 key.type = BTRFS_INODE_REF_KEY; 1261 key.offset = (u64)-1; 1262 1263 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); 1264 if (ret < 0) { 1265 goto err; 1266 } else if (ret > 0) { 1267 ret = btrfs_previous_item(fs_root, path, dirid, 1268 BTRFS_INODE_REF_KEY); 1269 if (ret < 0) { 1270 goto err; 1271 } else if (ret > 0) { 1272 ret = -ENOENT; 1273 goto err; 1274 } 1275 } 1276 1277 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 1278 dirid = key.offset; 1279 1280 inode_ref = btrfs_item_ptr(path->nodes[0], 1281 path->slots[0], 1282 struct btrfs_inode_ref); 1283 len = btrfs_inode_ref_name_len(path->nodes[0], 1284 inode_ref); 1285 ptr -= len + 1; 1286 if (ptr < name) { 1287 ret = -ENAMETOOLONG; 1288 goto err; 1289 } 1290 read_extent_buffer(path->nodes[0], ptr + 1, 1291 (unsigned long)(inode_ref + 1), len); 1292 ptr[0] = '/'; 1293 btrfs_release_path(path); 1294 } 1295 btrfs_put_root(fs_root); 1296 fs_root = NULL; 1297 } 1298 1299 btrfs_free_path(path); 1300 if (ptr == name + PATH_MAX - 1) { 1301 name[0] = '/'; 1302 name[1] = '\0'; 1303 } else { 1304 memmove(name, ptr, name + PATH_MAX - ptr); 1305 } 1306 return name; 1307 1308 err: 1309 btrfs_put_root(fs_root); 1310 btrfs_free_path(path); 1311 kfree(name); 1312 return ERR_PTR(ret); 1313 } 1314 1315 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid) 1316 { 1317 struct btrfs_root *root = fs_info->tree_root; 1318 struct btrfs_dir_item *di; 1319 struct btrfs_path *path; 1320 struct btrfs_key location; 1321 u64 dir_id; 1322 1323 path = btrfs_alloc_path(); 1324 if (!path) 1325 return -ENOMEM; 1326 1327 /* 1328 * Find the "default" dir item which points to the root item that we 1329 * will mount by default if we haven't been given a specific subvolume 1330 * to mount. 1331 */ 1332 dir_id = btrfs_super_root_dir(fs_info->super_copy); 1333 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 1334 if (IS_ERR(di)) { 1335 btrfs_free_path(path); 1336 return PTR_ERR(di); 1337 } 1338 if (!di) { 1339 /* 1340 * Ok the default dir item isn't there. This is weird since 1341 * it's always been there, but don't freak out, just try and 1342 * mount the top-level subvolume. 1343 */ 1344 btrfs_free_path(path); 1345 *objectid = BTRFS_FS_TREE_OBJECTID; 1346 return 0; 1347 } 1348 1349 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 1350 btrfs_free_path(path); 1351 *objectid = location.objectid; 1352 return 0; 1353 } 1354 1355 static int btrfs_fill_super(struct super_block *sb, 1356 struct btrfs_fs_devices *fs_devices, 1357 void *data) 1358 { 1359 struct inode *inode; 1360 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1361 int err; 1362 1363 sb->s_maxbytes = MAX_LFS_FILESIZE; 1364 sb->s_magic = BTRFS_SUPER_MAGIC; 1365 sb->s_op = &btrfs_super_ops; 1366 sb->s_d_op = &btrfs_dentry_operations; 1367 sb->s_export_op = &btrfs_export_ops; 1368 sb->s_xattr = btrfs_xattr_handlers; 1369 sb->s_time_gran = 1; 1370 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 1371 sb->s_flags |= SB_POSIXACL; 1372 #endif 1373 sb->s_flags |= SB_I_VERSION; 1374 sb->s_iflags |= SB_I_CGROUPWB; 1375 1376 err = super_setup_bdi(sb); 1377 if (err) { 1378 btrfs_err(fs_info, "super_setup_bdi failed"); 1379 return err; 1380 } 1381 1382 err = open_ctree(sb, fs_devices, (char *)data); 1383 if (err) { 1384 btrfs_err(fs_info, "open_ctree failed"); 1385 return err; 1386 } 1387 1388 inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root); 1389 if (IS_ERR(inode)) { 1390 err = PTR_ERR(inode); 1391 goto fail_close; 1392 } 1393 1394 sb->s_root = d_make_root(inode); 1395 if (!sb->s_root) { 1396 err = -ENOMEM; 1397 goto fail_close; 1398 } 1399 1400 cleancache_init_fs(sb); 1401 sb->s_flags |= SB_ACTIVE; 1402 return 0; 1403 1404 fail_close: 1405 close_ctree(fs_info); 1406 return err; 1407 } 1408 1409 int btrfs_sync_fs(struct super_block *sb, int wait) 1410 { 1411 struct btrfs_trans_handle *trans; 1412 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1413 struct btrfs_root *root = fs_info->tree_root; 1414 1415 trace_btrfs_sync_fs(fs_info, wait); 1416 1417 if (!wait) { 1418 filemap_flush(fs_info->btree_inode->i_mapping); 1419 return 0; 1420 } 1421 1422 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 1423 1424 trans = btrfs_attach_transaction_barrier(root); 1425 if (IS_ERR(trans)) { 1426 /* no transaction, don't bother */ 1427 if (PTR_ERR(trans) == -ENOENT) { 1428 /* 1429 * Exit unless we have some pending changes 1430 * that need to go through commit 1431 */ 1432 if (fs_info->pending_changes == 0) 1433 return 0; 1434 /* 1435 * A non-blocking test if the fs is frozen. We must not 1436 * start a new transaction here otherwise a deadlock 1437 * happens. The pending operations are delayed to the 1438 * next commit after thawing. 1439 */ 1440 if (sb_start_write_trylock(sb)) 1441 sb_end_write(sb); 1442 else 1443 return 0; 1444 trans = btrfs_start_transaction(root, 0); 1445 } 1446 if (IS_ERR(trans)) 1447 return PTR_ERR(trans); 1448 } 1449 return btrfs_commit_transaction(trans); 1450 } 1451 1452 static void print_rescue_option(struct seq_file *seq, const char *s, bool *printed) 1453 { 1454 seq_printf(seq, "%s%s", (*printed) ? ":" : ",rescue=", s); 1455 *printed = true; 1456 } 1457 1458 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) 1459 { 1460 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); 1461 const char *compress_type; 1462 const char *subvol_name; 1463 bool printed = false; 1464 1465 if (btrfs_test_opt(info, DEGRADED)) 1466 seq_puts(seq, ",degraded"); 1467 if (btrfs_test_opt(info, NODATASUM)) 1468 seq_puts(seq, ",nodatasum"); 1469 if (btrfs_test_opt(info, NODATACOW)) 1470 seq_puts(seq, ",nodatacow"); 1471 if (btrfs_test_opt(info, NOBARRIER)) 1472 seq_puts(seq, ",nobarrier"); 1473 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) 1474 seq_printf(seq, ",max_inline=%llu", info->max_inline); 1475 if (info->thread_pool_size != min_t(unsigned long, 1476 num_online_cpus() + 2, 8)) 1477 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size); 1478 if (btrfs_test_opt(info, COMPRESS)) { 1479 compress_type = btrfs_compress_type2str(info->compress_type); 1480 if (btrfs_test_opt(info, FORCE_COMPRESS)) 1481 seq_printf(seq, ",compress-force=%s", compress_type); 1482 else 1483 seq_printf(seq, ",compress=%s", compress_type); 1484 if (info->compress_level) 1485 seq_printf(seq, ":%d", info->compress_level); 1486 } 1487 if (btrfs_test_opt(info, NOSSD)) 1488 seq_puts(seq, ",nossd"); 1489 if (btrfs_test_opt(info, SSD_SPREAD)) 1490 seq_puts(seq, ",ssd_spread"); 1491 else if (btrfs_test_opt(info, SSD)) 1492 seq_puts(seq, ",ssd"); 1493 if (btrfs_test_opt(info, NOTREELOG)) 1494 seq_puts(seq, ",notreelog"); 1495 if (btrfs_test_opt(info, NOLOGREPLAY)) 1496 print_rescue_option(seq, "nologreplay", &printed); 1497 if (btrfs_test_opt(info, USEBACKUPROOT)) 1498 print_rescue_option(seq, "usebackuproot", &printed); 1499 if (btrfs_test_opt(info, IGNOREBADROOTS)) 1500 print_rescue_option(seq, "ignorebadroots", &printed); 1501 if (btrfs_test_opt(info, IGNOREDATACSUMS)) 1502 print_rescue_option(seq, "ignoredatacsums", &printed); 1503 if (btrfs_test_opt(info, FLUSHONCOMMIT)) 1504 seq_puts(seq, ",flushoncommit"); 1505 if (btrfs_test_opt(info, DISCARD_SYNC)) 1506 seq_puts(seq, ",discard"); 1507 if (btrfs_test_opt(info, DISCARD_ASYNC)) 1508 seq_puts(seq, ",discard=async"); 1509 if (!(info->sb->s_flags & SB_POSIXACL)) 1510 seq_puts(seq, ",noacl"); 1511 if (btrfs_free_space_cache_v1_active(info)) 1512 seq_puts(seq, ",space_cache"); 1513 else if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE)) 1514 seq_puts(seq, ",space_cache=v2"); 1515 else 1516 seq_puts(seq, ",nospace_cache"); 1517 if (btrfs_test_opt(info, RESCAN_UUID_TREE)) 1518 seq_puts(seq, ",rescan_uuid_tree"); 1519 if (btrfs_test_opt(info, CLEAR_CACHE)) 1520 seq_puts(seq, ",clear_cache"); 1521 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED)) 1522 seq_puts(seq, ",user_subvol_rm_allowed"); 1523 if (btrfs_test_opt(info, ENOSPC_DEBUG)) 1524 seq_puts(seq, ",enospc_debug"); 1525 if (btrfs_test_opt(info, AUTO_DEFRAG)) 1526 seq_puts(seq, ",autodefrag"); 1527 if (btrfs_test_opt(info, SKIP_BALANCE)) 1528 seq_puts(seq, ",skip_balance"); 1529 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 1530 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA)) 1531 seq_puts(seq, ",check_int_data"); 1532 else if (btrfs_test_opt(info, CHECK_INTEGRITY)) 1533 seq_puts(seq, ",check_int"); 1534 if (info->check_integrity_print_mask) 1535 seq_printf(seq, ",check_int_print_mask=%d", 1536 info->check_integrity_print_mask); 1537 #endif 1538 if (info->metadata_ratio) 1539 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio); 1540 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR)) 1541 seq_puts(seq, ",fatal_errors=panic"); 1542 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) 1543 seq_printf(seq, ",commit=%u", info->commit_interval); 1544 #ifdef CONFIG_BTRFS_DEBUG 1545 if (btrfs_test_opt(info, FRAGMENT_DATA)) 1546 seq_puts(seq, ",fragment=data"); 1547 if (btrfs_test_opt(info, FRAGMENT_METADATA)) 1548 seq_puts(seq, ",fragment=metadata"); 1549 #endif 1550 if (btrfs_test_opt(info, REF_VERIFY)) 1551 seq_puts(seq, ",ref_verify"); 1552 seq_printf(seq, ",subvolid=%llu", 1553 BTRFS_I(d_inode(dentry))->root->root_key.objectid); 1554 subvol_name = btrfs_get_subvol_name_from_objectid(info, 1555 BTRFS_I(d_inode(dentry))->root->root_key.objectid); 1556 if (!IS_ERR(subvol_name)) { 1557 seq_puts(seq, ",subvol="); 1558 seq_escape(seq, subvol_name, " \t\n\\"); 1559 kfree(subvol_name); 1560 } 1561 return 0; 1562 } 1563 1564 static int btrfs_test_super(struct super_block *s, void *data) 1565 { 1566 struct btrfs_fs_info *p = data; 1567 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1568 1569 return fs_info->fs_devices == p->fs_devices; 1570 } 1571 1572 static int btrfs_set_super(struct super_block *s, void *data) 1573 { 1574 int err = set_anon_super(s, data); 1575 if (!err) 1576 s->s_fs_info = data; 1577 return err; 1578 } 1579 1580 /* 1581 * subvolumes are identified by ino 256 1582 */ 1583 static inline int is_subvolume_inode(struct inode *inode) 1584 { 1585 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 1586 return 1; 1587 return 0; 1588 } 1589 1590 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid, 1591 struct vfsmount *mnt) 1592 { 1593 struct dentry *root; 1594 int ret; 1595 1596 if (!subvol_name) { 1597 if (!subvol_objectid) { 1598 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb), 1599 &subvol_objectid); 1600 if (ret) { 1601 root = ERR_PTR(ret); 1602 goto out; 1603 } 1604 } 1605 subvol_name = btrfs_get_subvol_name_from_objectid( 1606 btrfs_sb(mnt->mnt_sb), subvol_objectid); 1607 if (IS_ERR(subvol_name)) { 1608 root = ERR_CAST(subvol_name); 1609 subvol_name = NULL; 1610 goto out; 1611 } 1612 1613 } 1614 1615 root = mount_subtree(mnt, subvol_name); 1616 /* mount_subtree() drops our reference on the vfsmount. */ 1617 mnt = NULL; 1618 1619 if (!IS_ERR(root)) { 1620 struct super_block *s = root->d_sb; 1621 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1622 struct inode *root_inode = d_inode(root); 1623 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid; 1624 1625 ret = 0; 1626 if (!is_subvolume_inode(root_inode)) { 1627 btrfs_err(fs_info, "'%s' is not a valid subvolume", 1628 subvol_name); 1629 ret = -EINVAL; 1630 } 1631 if (subvol_objectid && root_objectid != subvol_objectid) { 1632 /* 1633 * This will also catch a race condition where a 1634 * subvolume which was passed by ID is renamed and 1635 * another subvolume is renamed over the old location. 1636 */ 1637 btrfs_err(fs_info, 1638 "subvol '%s' does not match subvolid %llu", 1639 subvol_name, subvol_objectid); 1640 ret = -EINVAL; 1641 } 1642 if (ret) { 1643 dput(root); 1644 root = ERR_PTR(ret); 1645 deactivate_locked_super(s); 1646 } 1647 } 1648 1649 out: 1650 mntput(mnt); 1651 kfree(subvol_name); 1652 return root; 1653 } 1654 1655 /* 1656 * Find a superblock for the given device / mount point. 1657 * 1658 * Note: This is based on mount_bdev from fs/super.c with a few additions 1659 * for multiple device setup. Make sure to keep it in sync. 1660 */ 1661 static struct dentry *btrfs_mount_root(struct file_system_type *fs_type, 1662 int flags, const char *device_name, void *data) 1663 { 1664 struct block_device *bdev = NULL; 1665 struct super_block *s; 1666 struct btrfs_device *device = NULL; 1667 struct btrfs_fs_devices *fs_devices = NULL; 1668 struct btrfs_fs_info *fs_info = NULL; 1669 void *new_sec_opts = NULL; 1670 fmode_t mode = FMODE_READ; 1671 int error = 0; 1672 1673 if (!(flags & SB_RDONLY)) 1674 mode |= FMODE_WRITE; 1675 1676 if (data) { 1677 error = security_sb_eat_lsm_opts(data, &new_sec_opts); 1678 if (error) 1679 return ERR_PTR(error); 1680 } 1681 1682 /* 1683 * Setup a dummy root and fs_info for test/set super. This is because 1684 * we don't actually fill this stuff out until open_ctree, but we need 1685 * then open_ctree will properly initialize the file system specific 1686 * settings later. btrfs_init_fs_info initializes the static elements 1687 * of the fs_info (locks and such) to make cleanup easier if we find a 1688 * superblock with our given fs_devices later on at sget() time. 1689 */ 1690 fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL); 1691 if (!fs_info) { 1692 error = -ENOMEM; 1693 goto error_sec_opts; 1694 } 1695 btrfs_init_fs_info(fs_info); 1696 1697 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); 1698 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL); 1699 if (!fs_info->super_copy || !fs_info->super_for_commit) { 1700 error = -ENOMEM; 1701 goto error_fs_info; 1702 } 1703 1704 mutex_lock(&uuid_mutex); 1705 error = btrfs_parse_device_options(data, mode, fs_type); 1706 if (error) { 1707 mutex_unlock(&uuid_mutex); 1708 goto error_fs_info; 1709 } 1710 1711 device = btrfs_scan_one_device(device_name, mode, fs_type); 1712 if (IS_ERR(device)) { 1713 mutex_unlock(&uuid_mutex); 1714 error = PTR_ERR(device); 1715 goto error_fs_info; 1716 } 1717 1718 fs_devices = device->fs_devices; 1719 fs_info->fs_devices = fs_devices; 1720 1721 error = btrfs_open_devices(fs_devices, mode, fs_type); 1722 mutex_unlock(&uuid_mutex); 1723 if (error) 1724 goto error_fs_info; 1725 1726 if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) { 1727 error = -EACCES; 1728 goto error_close_devices; 1729 } 1730 1731 bdev = fs_devices->latest_bdev; 1732 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC, 1733 fs_info); 1734 if (IS_ERR(s)) { 1735 error = PTR_ERR(s); 1736 goto error_close_devices; 1737 } 1738 1739 if (s->s_root) { 1740 btrfs_close_devices(fs_devices); 1741 btrfs_free_fs_info(fs_info); 1742 if ((flags ^ s->s_flags) & SB_RDONLY) 1743 error = -EBUSY; 1744 } else { 1745 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); 1746 btrfs_sb(s)->bdev_holder = fs_type; 1747 if (!strstr(crc32c_impl(), "generic")) 1748 set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags); 1749 error = btrfs_fill_super(s, fs_devices, data); 1750 } 1751 if (!error) 1752 error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL); 1753 security_free_mnt_opts(&new_sec_opts); 1754 if (error) { 1755 deactivate_locked_super(s); 1756 return ERR_PTR(error); 1757 } 1758 1759 return dget(s->s_root); 1760 1761 error_close_devices: 1762 btrfs_close_devices(fs_devices); 1763 error_fs_info: 1764 btrfs_free_fs_info(fs_info); 1765 error_sec_opts: 1766 security_free_mnt_opts(&new_sec_opts); 1767 return ERR_PTR(error); 1768 } 1769 1770 /* 1771 * Mount function which is called by VFS layer. 1772 * 1773 * In order to allow mounting a subvolume directly, btrfs uses mount_subtree() 1774 * which needs vfsmount* of device's root (/). This means device's root has to 1775 * be mounted internally in any case. 1776 * 1777 * Operation flow: 1778 * 1. Parse subvol id related options for later use in mount_subvol(). 1779 * 1780 * 2. Mount device's root (/) by calling vfs_kern_mount(). 1781 * 1782 * NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the 1783 * first place. In order to avoid calling btrfs_mount() again, we use 1784 * different file_system_type which is not registered to VFS by 1785 * register_filesystem() (btrfs_root_fs_type). As a result, 1786 * btrfs_mount_root() is called. The return value will be used by 1787 * mount_subtree() in mount_subvol(). 1788 * 1789 * 3. Call mount_subvol() to get the dentry of subvolume. Since there is 1790 * "btrfs subvolume set-default", mount_subvol() is called always. 1791 */ 1792 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 1793 const char *device_name, void *data) 1794 { 1795 struct vfsmount *mnt_root; 1796 struct dentry *root; 1797 char *subvol_name = NULL; 1798 u64 subvol_objectid = 0; 1799 int error = 0; 1800 1801 error = btrfs_parse_subvol_options(data, &subvol_name, 1802 &subvol_objectid); 1803 if (error) { 1804 kfree(subvol_name); 1805 return ERR_PTR(error); 1806 } 1807 1808 /* mount device's root (/) */ 1809 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data); 1810 if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) { 1811 if (flags & SB_RDONLY) { 1812 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, 1813 flags & ~SB_RDONLY, device_name, data); 1814 } else { 1815 mnt_root = vfs_kern_mount(&btrfs_root_fs_type, 1816 flags | SB_RDONLY, device_name, data); 1817 if (IS_ERR(mnt_root)) { 1818 root = ERR_CAST(mnt_root); 1819 kfree(subvol_name); 1820 goto out; 1821 } 1822 1823 down_write(&mnt_root->mnt_sb->s_umount); 1824 error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL); 1825 up_write(&mnt_root->mnt_sb->s_umount); 1826 if (error < 0) { 1827 root = ERR_PTR(error); 1828 mntput(mnt_root); 1829 kfree(subvol_name); 1830 goto out; 1831 } 1832 } 1833 } 1834 if (IS_ERR(mnt_root)) { 1835 root = ERR_CAST(mnt_root); 1836 kfree(subvol_name); 1837 goto out; 1838 } 1839 1840 /* mount_subvol() will free subvol_name and mnt_root */ 1841 root = mount_subvol(subvol_name, subvol_objectid, mnt_root); 1842 1843 out: 1844 return root; 1845 } 1846 1847 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, 1848 u32 new_pool_size, u32 old_pool_size) 1849 { 1850 if (new_pool_size == old_pool_size) 1851 return; 1852 1853 fs_info->thread_pool_size = new_pool_size; 1854 1855 btrfs_info(fs_info, "resize thread pool %d -> %d", 1856 old_pool_size, new_pool_size); 1857 1858 btrfs_workqueue_set_max(fs_info->workers, new_pool_size); 1859 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size); 1860 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size); 1861 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size); 1862 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size); 1863 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers, 1864 new_pool_size); 1865 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size); 1866 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size); 1867 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size); 1868 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size); 1869 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers, 1870 new_pool_size); 1871 } 1872 1873 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info, 1874 unsigned long old_opts, int flags) 1875 { 1876 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1877 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1878 (flags & SB_RDONLY))) { 1879 /* wait for any defraggers to finish */ 1880 wait_event(fs_info->transaction_wait, 1881 (atomic_read(&fs_info->defrag_running) == 0)); 1882 if (flags & SB_RDONLY) 1883 sync_filesystem(fs_info->sb); 1884 } 1885 } 1886 1887 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info, 1888 unsigned long old_opts) 1889 { 1890 const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE); 1891 1892 /* 1893 * We need to cleanup all defragable inodes if the autodefragment is 1894 * close or the filesystem is read only. 1895 */ 1896 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1897 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) { 1898 btrfs_cleanup_defrag_inodes(fs_info); 1899 } 1900 1901 /* If we toggled discard async */ 1902 if (!btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) && 1903 btrfs_test_opt(fs_info, DISCARD_ASYNC)) 1904 btrfs_discard_resume(fs_info); 1905 else if (btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) && 1906 !btrfs_test_opt(fs_info, DISCARD_ASYNC)) 1907 btrfs_discard_cleanup(fs_info); 1908 1909 /* If we toggled space cache */ 1910 if (cache_opt != btrfs_free_space_cache_v1_active(fs_info)) 1911 btrfs_set_free_space_cache_v1_active(fs_info, cache_opt); 1912 } 1913 1914 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1915 { 1916 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1917 unsigned old_flags = sb->s_flags; 1918 unsigned long old_opts = fs_info->mount_opt; 1919 unsigned long old_compress_type = fs_info->compress_type; 1920 u64 old_max_inline = fs_info->max_inline; 1921 u32 old_thread_pool_size = fs_info->thread_pool_size; 1922 u32 old_metadata_ratio = fs_info->metadata_ratio; 1923 int ret; 1924 1925 sync_filesystem(sb); 1926 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1927 1928 if (data) { 1929 void *new_sec_opts = NULL; 1930 1931 ret = security_sb_eat_lsm_opts(data, &new_sec_opts); 1932 if (!ret) 1933 ret = security_sb_remount(sb, new_sec_opts); 1934 security_free_mnt_opts(&new_sec_opts); 1935 if (ret) 1936 goto restore; 1937 } 1938 1939 ret = btrfs_parse_options(fs_info, data, *flags); 1940 if (ret) 1941 goto restore; 1942 1943 btrfs_remount_begin(fs_info, old_opts, *flags); 1944 btrfs_resize_thread_pool(fs_info, 1945 fs_info->thread_pool_size, old_thread_pool_size); 1946 1947 if ((bool)btrfs_test_opt(fs_info, FREE_SPACE_TREE) != 1948 (bool)btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) && 1949 (!sb_rdonly(sb) || (*flags & SB_RDONLY))) { 1950 btrfs_warn(fs_info, 1951 "remount supports changing free space tree only from ro to rw"); 1952 /* Make sure free space cache options match the state on disk */ 1953 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) { 1954 btrfs_set_opt(fs_info->mount_opt, FREE_SPACE_TREE); 1955 btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE); 1956 } 1957 if (btrfs_free_space_cache_v1_active(fs_info)) { 1958 btrfs_clear_opt(fs_info->mount_opt, FREE_SPACE_TREE); 1959 btrfs_set_opt(fs_info->mount_opt, SPACE_CACHE); 1960 } 1961 } 1962 1963 if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb)) 1964 goto out; 1965 1966 if (*flags & SB_RDONLY) { 1967 /* 1968 * this also happens on 'umount -rf' or on shutdown, when 1969 * the filesystem is busy. 1970 */ 1971 cancel_work_sync(&fs_info->async_reclaim_work); 1972 cancel_work_sync(&fs_info->async_data_reclaim_work); 1973 1974 btrfs_discard_cleanup(fs_info); 1975 1976 /* wait for the uuid_scan task to finish */ 1977 down(&fs_info->uuid_tree_rescan_sem); 1978 /* avoid complains from lockdep et al. */ 1979 up(&fs_info->uuid_tree_rescan_sem); 1980 1981 btrfs_set_sb_rdonly(sb); 1982 1983 /* 1984 * Setting SB_RDONLY will put the cleaner thread to 1985 * sleep at the next loop if it's already active. 1986 * If it's already asleep, we'll leave unused block 1987 * groups on disk until we're mounted read-write again 1988 * unless we clean them up here. 1989 */ 1990 btrfs_delete_unused_bgs(fs_info); 1991 1992 /* 1993 * The cleaner task could be already running before we set the 1994 * flag BTRFS_FS_STATE_RO (and SB_RDONLY in the superblock). 1995 * We must make sure that after we finish the remount, i.e. after 1996 * we call btrfs_commit_super(), the cleaner can no longer start 1997 * a transaction - either because it was dropping a dead root, 1998 * running delayed iputs or deleting an unused block group (the 1999 * cleaner picked a block group from the list of unused block 2000 * groups before we were able to in the previous call to 2001 * btrfs_delete_unused_bgs()). 2002 */ 2003 wait_on_bit(&fs_info->flags, BTRFS_FS_CLEANER_RUNNING, 2004 TASK_UNINTERRUPTIBLE); 2005 2006 /* 2007 * We've set the superblock to RO mode, so we might have made 2008 * the cleaner task sleep without running all pending delayed 2009 * iputs. Go through all the delayed iputs here, so that if an 2010 * unmount happens without remounting RW we don't end up at 2011 * finishing close_ctree() with a non-empty list of delayed 2012 * iputs. 2013 */ 2014 btrfs_run_delayed_iputs(fs_info); 2015 2016 btrfs_dev_replace_suspend_for_unmount(fs_info); 2017 btrfs_scrub_cancel(fs_info); 2018 btrfs_pause_balance(fs_info); 2019 2020 /* 2021 * Pause the qgroup rescan worker if it is running. We don't want 2022 * it to be still running after we are in RO mode, as after that, 2023 * by the time we unmount, it might have left a transaction open, 2024 * so we would leak the transaction and/or crash. 2025 */ 2026 btrfs_qgroup_wait_for_completion(fs_info, false); 2027 2028 ret = btrfs_commit_super(fs_info); 2029 if (ret) 2030 goto restore; 2031 } else { 2032 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { 2033 btrfs_err(fs_info, 2034 "Remounting read-write after error is not allowed"); 2035 ret = -EINVAL; 2036 goto restore; 2037 } 2038 if (fs_info->fs_devices->rw_devices == 0) { 2039 ret = -EACCES; 2040 goto restore; 2041 } 2042 2043 if (!btrfs_check_rw_degradable(fs_info, NULL)) { 2044 btrfs_warn(fs_info, 2045 "too many missing devices, writable remount is not allowed"); 2046 ret = -EACCES; 2047 goto restore; 2048 } 2049 2050 if (btrfs_super_log_root(fs_info->super_copy) != 0) { 2051 btrfs_warn(fs_info, 2052 "mount required to replay tree-log, cannot remount read-write"); 2053 ret = -EINVAL; 2054 goto restore; 2055 } 2056 if (fs_info->sectorsize < PAGE_SIZE) { 2057 btrfs_warn(fs_info, 2058 "read-write mount is not yet allowed for sectorsize %u page size %lu", 2059 fs_info->sectorsize, PAGE_SIZE); 2060 ret = -EINVAL; 2061 goto restore; 2062 } 2063 2064 /* 2065 * NOTE: when remounting with a change that does writes, don't 2066 * put it anywhere above this point, as we are not sure to be 2067 * safe to write until we pass the above checks. 2068 */ 2069 ret = btrfs_start_pre_rw_mount(fs_info); 2070 if (ret) 2071 goto restore; 2072 2073 btrfs_clear_sb_rdonly(sb); 2074 2075 set_bit(BTRFS_FS_OPEN, &fs_info->flags); 2076 } 2077 out: 2078 /* 2079 * We need to set SB_I_VERSION here otherwise it'll get cleared by VFS, 2080 * since the absence of the flag means it can be toggled off by remount. 2081 */ 2082 *flags |= SB_I_VERSION; 2083 2084 wake_up_process(fs_info->transaction_kthread); 2085 btrfs_remount_cleanup(fs_info, old_opts); 2086 btrfs_clear_oneshot_options(fs_info); 2087 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 2088 2089 return 0; 2090 2091 restore: 2092 /* We've hit an error - don't reset SB_RDONLY */ 2093 if (sb_rdonly(sb)) 2094 old_flags |= SB_RDONLY; 2095 if (!(old_flags & SB_RDONLY)) 2096 clear_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state); 2097 sb->s_flags = old_flags; 2098 fs_info->mount_opt = old_opts; 2099 fs_info->compress_type = old_compress_type; 2100 fs_info->max_inline = old_max_inline; 2101 btrfs_resize_thread_pool(fs_info, 2102 old_thread_pool_size, fs_info->thread_pool_size); 2103 fs_info->metadata_ratio = old_metadata_ratio; 2104 btrfs_remount_cleanup(fs_info, old_opts); 2105 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 2106 2107 return ret; 2108 } 2109 2110 /* Used to sort the devices by max_avail(descending sort) */ 2111 static inline int btrfs_cmp_device_free_bytes(const void *dev_info1, 2112 const void *dev_info2) 2113 { 2114 if (((struct btrfs_device_info *)dev_info1)->max_avail > 2115 ((struct btrfs_device_info *)dev_info2)->max_avail) 2116 return -1; 2117 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 2118 ((struct btrfs_device_info *)dev_info2)->max_avail) 2119 return 1; 2120 else 2121 return 0; 2122 } 2123 2124 /* 2125 * sort the devices by max_avail, in which max free extent size of each device 2126 * is stored.(Descending Sort) 2127 */ 2128 static inline void btrfs_descending_sort_devices( 2129 struct btrfs_device_info *devices, 2130 size_t nr_devices) 2131 { 2132 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 2133 btrfs_cmp_device_free_bytes, NULL); 2134 } 2135 2136 /* 2137 * The helper to calc the free space on the devices that can be used to store 2138 * file data. 2139 */ 2140 static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info, 2141 u64 *free_bytes) 2142 { 2143 struct btrfs_device_info *devices_info; 2144 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 2145 struct btrfs_device *device; 2146 u64 type; 2147 u64 avail_space; 2148 u64 min_stripe_size; 2149 int num_stripes = 1; 2150 int i = 0, nr_devices; 2151 const struct btrfs_raid_attr *rattr; 2152 2153 /* 2154 * We aren't under the device list lock, so this is racy-ish, but good 2155 * enough for our purposes. 2156 */ 2157 nr_devices = fs_info->fs_devices->open_devices; 2158 if (!nr_devices) { 2159 smp_mb(); 2160 nr_devices = fs_info->fs_devices->open_devices; 2161 ASSERT(nr_devices); 2162 if (!nr_devices) { 2163 *free_bytes = 0; 2164 return 0; 2165 } 2166 } 2167 2168 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info), 2169 GFP_KERNEL); 2170 if (!devices_info) 2171 return -ENOMEM; 2172 2173 /* calc min stripe number for data space allocation */ 2174 type = btrfs_data_alloc_profile(fs_info); 2175 rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)]; 2176 2177 if (type & BTRFS_BLOCK_GROUP_RAID0) 2178 num_stripes = nr_devices; 2179 else if (type & BTRFS_BLOCK_GROUP_RAID1) 2180 num_stripes = 2; 2181 else if (type & BTRFS_BLOCK_GROUP_RAID1C3) 2182 num_stripes = 3; 2183 else if (type & BTRFS_BLOCK_GROUP_RAID1C4) 2184 num_stripes = 4; 2185 else if (type & BTRFS_BLOCK_GROUP_RAID10) 2186 num_stripes = 4; 2187 2188 /* Adjust for more than 1 stripe per device */ 2189 min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN; 2190 2191 rcu_read_lock(); 2192 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { 2193 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, 2194 &device->dev_state) || 2195 !device->bdev || 2196 test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) 2197 continue; 2198 2199 if (i >= nr_devices) 2200 break; 2201 2202 avail_space = device->total_bytes - device->bytes_used; 2203 2204 /* align with stripe_len */ 2205 avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN); 2206 2207 /* 2208 * In order to avoid overwriting the superblock on the drive, 2209 * btrfs starts at an offset of at least 1MB when doing chunk 2210 * allocation. 2211 * 2212 * This ensures we have at least min_stripe_size free space 2213 * after excluding 1MB. 2214 */ 2215 if (avail_space <= SZ_1M + min_stripe_size) 2216 continue; 2217 2218 avail_space -= SZ_1M; 2219 2220 devices_info[i].dev = device; 2221 devices_info[i].max_avail = avail_space; 2222 2223 i++; 2224 } 2225 rcu_read_unlock(); 2226 2227 nr_devices = i; 2228 2229 btrfs_descending_sort_devices(devices_info, nr_devices); 2230 2231 i = nr_devices - 1; 2232 avail_space = 0; 2233 while (nr_devices >= rattr->devs_min) { 2234 num_stripes = min(num_stripes, nr_devices); 2235 2236 if (devices_info[i].max_avail >= min_stripe_size) { 2237 int j; 2238 u64 alloc_size; 2239 2240 avail_space += devices_info[i].max_avail * num_stripes; 2241 alloc_size = devices_info[i].max_avail; 2242 for (j = i + 1 - num_stripes; j <= i; j++) 2243 devices_info[j].max_avail -= alloc_size; 2244 } 2245 i--; 2246 nr_devices--; 2247 } 2248 2249 kfree(devices_info); 2250 *free_bytes = avail_space; 2251 return 0; 2252 } 2253 2254 /* 2255 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles. 2256 * 2257 * If there's a redundant raid level at DATA block groups, use the respective 2258 * multiplier to scale the sizes. 2259 * 2260 * Unused device space usage is based on simulating the chunk allocator 2261 * algorithm that respects the device sizes and order of allocations. This is 2262 * a close approximation of the actual use but there are other factors that may 2263 * change the result (like a new metadata chunk). 2264 * 2265 * If metadata is exhausted, f_bavail will be 0. 2266 */ 2267 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 2268 { 2269 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); 2270 struct btrfs_super_block *disk_super = fs_info->super_copy; 2271 struct btrfs_space_info *found; 2272 u64 total_used = 0; 2273 u64 total_free_data = 0; 2274 u64 total_free_meta = 0; 2275 u32 bits = fs_info->sectorsize_bits; 2276 __be32 *fsid = (__be32 *)fs_info->fs_devices->fsid; 2277 unsigned factor = 1; 2278 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 2279 int ret; 2280 u64 thresh = 0; 2281 int mixed = 0; 2282 2283 list_for_each_entry(found, &fs_info->space_info, list) { 2284 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 2285 int i; 2286 2287 total_free_data += found->disk_total - found->disk_used; 2288 total_free_data -= 2289 btrfs_account_ro_block_groups_free_space(found); 2290 2291 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { 2292 if (!list_empty(&found->block_groups[i])) 2293 factor = btrfs_bg_type_to_factor( 2294 btrfs_raid_array[i].bg_flag); 2295 } 2296 } 2297 2298 /* 2299 * Metadata in mixed block goup profiles are accounted in data 2300 */ 2301 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) { 2302 if (found->flags & BTRFS_BLOCK_GROUP_DATA) 2303 mixed = 1; 2304 else 2305 total_free_meta += found->disk_total - 2306 found->disk_used; 2307 } 2308 2309 total_used += found->disk_used; 2310 } 2311 2312 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor); 2313 buf->f_blocks >>= bits; 2314 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits); 2315 2316 /* Account global block reserve as used, it's in logical size already */ 2317 spin_lock(&block_rsv->lock); 2318 /* Mixed block groups accounting is not byte-accurate, avoid overflow */ 2319 if (buf->f_bfree >= block_rsv->size >> bits) 2320 buf->f_bfree -= block_rsv->size >> bits; 2321 else 2322 buf->f_bfree = 0; 2323 spin_unlock(&block_rsv->lock); 2324 2325 buf->f_bavail = div_u64(total_free_data, factor); 2326 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data); 2327 if (ret) 2328 return ret; 2329 buf->f_bavail += div_u64(total_free_data, factor); 2330 buf->f_bavail = buf->f_bavail >> bits; 2331 2332 /* 2333 * We calculate the remaining metadata space minus global reserve. If 2334 * this is (supposedly) smaller than zero, there's no space. But this 2335 * does not hold in practice, the exhausted state happens where's still 2336 * some positive delta. So we apply some guesswork and compare the 2337 * delta to a 4M threshold. (Practically observed delta was ~2M.) 2338 * 2339 * We probably cannot calculate the exact threshold value because this 2340 * depends on the internal reservations requested by various 2341 * operations, so some operations that consume a few metadata will 2342 * succeed even if the Avail is zero. But this is better than the other 2343 * way around. 2344 */ 2345 thresh = SZ_4M; 2346 2347 /* 2348 * We only want to claim there's no available space if we can no longer 2349 * allocate chunks for our metadata profile and our global reserve will 2350 * not fit in the free metadata space. If we aren't ->full then we 2351 * still can allocate chunks and thus are fine using the currently 2352 * calculated f_bavail. 2353 */ 2354 if (!mixed && block_rsv->space_info->full && 2355 total_free_meta - thresh < block_rsv->size) 2356 buf->f_bavail = 0; 2357 2358 buf->f_type = BTRFS_SUPER_MAGIC; 2359 buf->f_bsize = dentry->d_sb->s_blocksize; 2360 buf->f_namelen = BTRFS_NAME_LEN; 2361 2362 /* We treat it as constant endianness (it doesn't matter _which_) 2363 because we want the fsid to come out the same whether mounted 2364 on a big-endian or little-endian host */ 2365 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 2366 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 2367 /* Mask in the root object ID too, to disambiguate subvols */ 2368 buf->f_fsid.val[0] ^= 2369 BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32; 2370 buf->f_fsid.val[1] ^= 2371 BTRFS_I(d_inode(dentry))->root->root_key.objectid; 2372 2373 return 0; 2374 } 2375 2376 static void btrfs_kill_super(struct super_block *sb) 2377 { 2378 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2379 kill_anon_super(sb); 2380 btrfs_free_fs_info(fs_info); 2381 } 2382 2383 static struct file_system_type btrfs_fs_type = { 2384 .owner = THIS_MODULE, 2385 .name = "btrfs", 2386 .mount = btrfs_mount, 2387 .kill_sb = btrfs_kill_super, 2388 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, 2389 }; 2390 2391 static struct file_system_type btrfs_root_fs_type = { 2392 .owner = THIS_MODULE, 2393 .name = "btrfs", 2394 .mount = btrfs_mount_root, 2395 .kill_sb = btrfs_kill_super, 2396 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, 2397 }; 2398 2399 MODULE_ALIAS_FS("btrfs"); 2400 2401 static int btrfs_control_open(struct inode *inode, struct file *file) 2402 { 2403 /* 2404 * The control file's private_data is used to hold the 2405 * transaction when it is started and is used to keep 2406 * track of whether a transaction is already in progress. 2407 */ 2408 file->private_data = NULL; 2409 return 0; 2410 } 2411 2412 /* 2413 * Used by /dev/btrfs-control for devices ioctls. 2414 */ 2415 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 2416 unsigned long arg) 2417 { 2418 struct btrfs_ioctl_vol_args *vol; 2419 struct btrfs_device *device = NULL; 2420 int ret = -ENOTTY; 2421 2422 if (!capable(CAP_SYS_ADMIN)) 2423 return -EPERM; 2424 2425 vol = memdup_user((void __user *)arg, sizeof(*vol)); 2426 if (IS_ERR(vol)) 2427 return PTR_ERR(vol); 2428 vol->name[BTRFS_PATH_NAME_MAX] = '\0'; 2429 2430 switch (cmd) { 2431 case BTRFS_IOC_SCAN_DEV: 2432 mutex_lock(&uuid_mutex); 2433 device = btrfs_scan_one_device(vol->name, FMODE_READ, 2434 &btrfs_root_fs_type); 2435 ret = PTR_ERR_OR_ZERO(device); 2436 mutex_unlock(&uuid_mutex); 2437 break; 2438 case BTRFS_IOC_FORGET_DEV: 2439 ret = btrfs_forget_devices(vol->name); 2440 break; 2441 case BTRFS_IOC_DEVICES_READY: 2442 mutex_lock(&uuid_mutex); 2443 device = btrfs_scan_one_device(vol->name, FMODE_READ, 2444 &btrfs_root_fs_type); 2445 if (IS_ERR(device)) { 2446 mutex_unlock(&uuid_mutex); 2447 ret = PTR_ERR(device); 2448 break; 2449 } 2450 ret = !(device->fs_devices->num_devices == 2451 device->fs_devices->total_devices); 2452 mutex_unlock(&uuid_mutex); 2453 break; 2454 case BTRFS_IOC_GET_SUPPORTED_FEATURES: 2455 ret = btrfs_ioctl_get_supported_features((void __user*)arg); 2456 break; 2457 } 2458 2459 kfree(vol); 2460 return ret; 2461 } 2462 2463 static int btrfs_freeze(struct super_block *sb) 2464 { 2465 struct btrfs_trans_handle *trans; 2466 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2467 struct btrfs_root *root = fs_info->tree_root; 2468 2469 set_bit(BTRFS_FS_FROZEN, &fs_info->flags); 2470 /* 2471 * We don't need a barrier here, we'll wait for any transaction that 2472 * could be in progress on other threads (and do delayed iputs that 2473 * we want to avoid on a frozen filesystem), or do the commit 2474 * ourselves. 2475 */ 2476 trans = btrfs_attach_transaction_barrier(root); 2477 if (IS_ERR(trans)) { 2478 /* no transaction, don't bother */ 2479 if (PTR_ERR(trans) == -ENOENT) 2480 return 0; 2481 return PTR_ERR(trans); 2482 } 2483 return btrfs_commit_transaction(trans); 2484 } 2485 2486 static int btrfs_unfreeze(struct super_block *sb) 2487 { 2488 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2489 2490 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags); 2491 return 0; 2492 } 2493 2494 static int btrfs_show_devname(struct seq_file *m, struct dentry *root) 2495 { 2496 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); 2497 struct btrfs_device *dev, *first_dev = NULL; 2498 2499 /* 2500 * Lightweight locking of the devices. We should not need 2501 * device_list_mutex here as we only read the device data and the list 2502 * is protected by RCU. Even if a device is deleted during the list 2503 * traversals, we'll get valid data, the freeing callback will wait at 2504 * least until the rcu_read_unlock. 2505 */ 2506 rcu_read_lock(); 2507 list_for_each_entry_rcu(dev, &fs_info->fs_devices->devices, dev_list) { 2508 if (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state)) 2509 continue; 2510 if (!dev->name) 2511 continue; 2512 if (!first_dev || dev->devid < first_dev->devid) 2513 first_dev = dev; 2514 } 2515 2516 if (first_dev) 2517 seq_escape(m, rcu_str_deref(first_dev->name), " \t\n\\"); 2518 else 2519 WARN_ON(1); 2520 rcu_read_unlock(); 2521 return 0; 2522 } 2523 2524 static const struct super_operations btrfs_super_ops = { 2525 .drop_inode = btrfs_drop_inode, 2526 .evict_inode = btrfs_evict_inode, 2527 .put_super = btrfs_put_super, 2528 .sync_fs = btrfs_sync_fs, 2529 .show_options = btrfs_show_options, 2530 .show_devname = btrfs_show_devname, 2531 .alloc_inode = btrfs_alloc_inode, 2532 .destroy_inode = btrfs_destroy_inode, 2533 .free_inode = btrfs_free_inode, 2534 .statfs = btrfs_statfs, 2535 .remount_fs = btrfs_remount, 2536 .freeze_fs = btrfs_freeze, 2537 .unfreeze_fs = btrfs_unfreeze, 2538 }; 2539 2540 static const struct file_operations btrfs_ctl_fops = { 2541 .open = btrfs_control_open, 2542 .unlocked_ioctl = btrfs_control_ioctl, 2543 .compat_ioctl = compat_ptr_ioctl, 2544 .owner = THIS_MODULE, 2545 .llseek = noop_llseek, 2546 }; 2547 2548 static struct miscdevice btrfs_misc = { 2549 .minor = BTRFS_MINOR, 2550 .name = "btrfs-control", 2551 .fops = &btrfs_ctl_fops 2552 }; 2553 2554 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 2555 MODULE_ALIAS("devname:btrfs-control"); 2556 2557 static int __init btrfs_interface_init(void) 2558 { 2559 return misc_register(&btrfs_misc); 2560 } 2561 2562 static __cold void btrfs_interface_exit(void) 2563 { 2564 misc_deregister(&btrfs_misc); 2565 } 2566 2567 static void __init btrfs_print_mod_info(void) 2568 { 2569 static const char options[] = "" 2570 #ifdef CONFIG_BTRFS_DEBUG 2571 ", debug=on" 2572 #endif 2573 #ifdef CONFIG_BTRFS_ASSERT 2574 ", assert=on" 2575 #endif 2576 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 2577 ", integrity-checker=on" 2578 #endif 2579 #ifdef CONFIG_BTRFS_FS_REF_VERIFY 2580 ", ref-verify=on" 2581 #endif 2582 #ifdef CONFIG_BLK_DEV_ZONED 2583 ", zoned=yes" 2584 #else 2585 ", zoned=no" 2586 #endif 2587 ; 2588 pr_info("Btrfs loaded, crc32c=%s%s\n", crc32c_impl(), options); 2589 } 2590 2591 static int __init init_btrfs_fs(void) 2592 { 2593 int err; 2594 2595 btrfs_props_init(); 2596 2597 err = btrfs_init_sysfs(); 2598 if (err) 2599 return err; 2600 2601 btrfs_init_compress(); 2602 2603 err = btrfs_init_cachep(); 2604 if (err) 2605 goto free_compress; 2606 2607 err = extent_io_init(); 2608 if (err) 2609 goto free_cachep; 2610 2611 err = extent_state_cache_init(); 2612 if (err) 2613 goto free_extent_io; 2614 2615 err = extent_map_init(); 2616 if (err) 2617 goto free_extent_state_cache; 2618 2619 err = ordered_data_init(); 2620 if (err) 2621 goto free_extent_map; 2622 2623 err = btrfs_delayed_inode_init(); 2624 if (err) 2625 goto free_ordered_data; 2626 2627 err = btrfs_auto_defrag_init(); 2628 if (err) 2629 goto free_delayed_inode; 2630 2631 err = btrfs_delayed_ref_init(); 2632 if (err) 2633 goto free_auto_defrag; 2634 2635 err = btrfs_prelim_ref_init(); 2636 if (err) 2637 goto free_delayed_ref; 2638 2639 err = btrfs_end_io_wq_init(); 2640 if (err) 2641 goto free_prelim_ref; 2642 2643 err = btrfs_interface_init(); 2644 if (err) 2645 goto free_end_io_wq; 2646 2647 btrfs_print_mod_info(); 2648 2649 err = btrfs_run_sanity_tests(); 2650 if (err) 2651 goto unregister_ioctl; 2652 2653 err = register_filesystem(&btrfs_fs_type); 2654 if (err) 2655 goto unregister_ioctl; 2656 2657 return 0; 2658 2659 unregister_ioctl: 2660 btrfs_interface_exit(); 2661 free_end_io_wq: 2662 btrfs_end_io_wq_exit(); 2663 free_prelim_ref: 2664 btrfs_prelim_ref_exit(); 2665 free_delayed_ref: 2666 btrfs_delayed_ref_exit(); 2667 free_auto_defrag: 2668 btrfs_auto_defrag_exit(); 2669 free_delayed_inode: 2670 btrfs_delayed_inode_exit(); 2671 free_ordered_data: 2672 ordered_data_exit(); 2673 free_extent_map: 2674 extent_map_exit(); 2675 free_extent_state_cache: 2676 extent_state_cache_exit(); 2677 free_extent_io: 2678 extent_io_exit(); 2679 free_cachep: 2680 btrfs_destroy_cachep(); 2681 free_compress: 2682 btrfs_exit_compress(); 2683 btrfs_exit_sysfs(); 2684 2685 return err; 2686 } 2687 2688 static void __exit exit_btrfs_fs(void) 2689 { 2690 btrfs_destroy_cachep(); 2691 btrfs_delayed_ref_exit(); 2692 btrfs_auto_defrag_exit(); 2693 btrfs_delayed_inode_exit(); 2694 btrfs_prelim_ref_exit(); 2695 ordered_data_exit(); 2696 extent_map_exit(); 2697 extent_state_cache_exit(); 2698 extent_io_exit(); 2699 btrfs_interface_exit(); 2700 btrfs_end_io_wq_exit(); 2701 unregister_filesystem(&btrfs_fs_type); 2702 btrfs_exit_sysfs(); 2703 btrfs_cleanup_fs_uuids(); 2704 btrfs_exit_compress(); 2705 } 2706 2707 late_initcall(init_btrfs_fs); 2708 module_exit(exit_btrfs_fs) 2709 2710 MODULE_LICENSE("GPL"); 2711 MODULE_SOFTDEP("pre: crc32c"); 2712 MODULE_SOFTDEP("pre: xxhash64"); 2713 MODULE_SOFTDEP("pre: sha256"); 2714 MODULE_SOFTDEP("pre: blake2b-256"); 2715