1 /* 2 * Copyright (C) 2007 Oracle. All rights reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public 6 * License v2 as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public 14 * License along with this program; if not, write to the 15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 16 * Boston, MA 021110-1307, USA. 17 */ 18 19 #include <linux/blkdev.h> 20 #include <linux/module.h> 21 #include <linux/buffer_head.h> 22 #include <linux/fs.h> 23 #include <linux/pagemap.h> 24 #include <linux/highmem.h> 25 #include <linux/time.h> 26 #include <linux/init.h> 27 #include <linux/seq_file.h> 28 #include <linux/string.h> 29 #include <linux/backing-dev.h> 30 #include <linux/mount.h> 31 #include <linux/mpage.h> 32 #include <linux/swap.h> 33 #include <linux/writeback.h> 34 #include <linux/statfs.h> 35 #include <linux/compat.h> 36 #include <linux/parser.h> 37 #include <linux/ctype.h> 38 #include <linux/namei.h> 39 #include <linux/miscdevice.h> 40 #include <linux/magic.h> 41 #include <linux/slab.h> 42 #include <linux/cleancache.h> 43 #include <linux/ratelimit.h> 44 #include <linux/btrfs.h> 45 #include "delayed-inode.h" 46 #include "ctree.h" 47 #include "disk-io.h" 48 #include "transaction.h" 49 #include "btrfs_inode.h" 50 #include "print-tree.h" 51 #include "hash.h" 52 #include "props.h" 53 #include "xattr.h" 54 #include "volumes.h" 55 #include "export.h" 56 #include "compression.h" 57 #include "rcu-string.h" 58 #include "dev-replace.h" 59 #include "free-space-cache.h" 60 #include "backref.h" 61 #include "tests/btrfs-tests.h" 62 63 #include "qgroup.h" 64 #define CREATE_TRACE_POINTS 65 #include <trace/events/btrfs.h> 66 67 static const struct super_operations btrfs_super_ops; 68 static struct file_system_type btrfs_fs_type; 69 70 static int btrfs_remount(struct super_block *sb, int *flags, char *data); 71 72 const char *btrfs_decode_error(int errno) 73 { 74 char *errstr = "unknown"; 75 76 switch (errno) { 77 case -EIO: 78 errstr = "IO failure"; 79 break; 80 case -ENOMEM: 81 errstr = "Out of memory"; 82 break; 83 case -EROFS: 84 errstr = "Readonly filesystem"; 85 break; 86 case -EEXIST: 87 errstr = "Object already exists"; 88 break; 89 case -ENOSPC: 90 errstr = "No space left"; 91 break; 92 case -ENOENT: 93 errstr = "No such entry"; 94 break; 95 } 96 97 return errstr; 98 } 99 100 static void save_error_info(struct btrfs_fs_info *fs_info) 101 { 102 /* 103 * today we only save the error info into ram. Long term we'll 104 * also send it down to the disk 105 */ 106 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state); 107 } 108 109 /* btrfs handle error by forcing the filesystem readonly */ 110 static void btrfs_handle_error(struct btrfs_fs_info *fs_info) 111 { 112 struct super_block *sb = fs_info->sb; 113 114 if (sb->s_flags & MS_RDONLY) 115 return; 116 117 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { 118 sb->s_flags |= MS_RDONLY; 119 btrfs_info(fs_info, "forced readonly"); 120 /* 121 * Note that a running device replace operation is not 122 * canceled here although there is no way to update 123 * the progress. It would add the risk of a deadlock, 124 * therefore the canceling is ommited. The only penalty 125 * is that some I/O remains active until the procedure 126 * completes. The next time when the filesystem is 127 * mounted writeable again, the device replace 128 * operation continues. 129 */ 130 } 131 } 132 133 /* 134 * __btrfs_std_error decodes expected errors from the caller and 135 * invokes the approciate error response. 136 */ 137 __cold 138 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, 139 unsigned int line, int errno, const char *fmt, ...) 140 { 141 struct super_block *sb = fs_info->sb; 142 #ifdef CONFIG_PRINTK 143 const char *errstr; 144 #endif 145 146 /* 147 * Special case: if the error is EROFS, and we're already 148 * under MS_RDONLY, then it is safe here. 149 */ 150 if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) 151 return; 152 153 #ifdef CONFIG_PRINTK 154 errstr = btrfs_decode_error(errno); 155 if (fmt) { 156 struct va_format vaf; 157 va_list args; 158 159 va_start(args, fmt); 160 vaf.fmt = fmt; 161 vaf.va = &args; 162 163 printk(KERN_CRIT 164 "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n", 165 sb->s_id, function, line, errno, errstr, &vaf); 166 va_end(args); 167 } else { 168 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n", 169 sb->s_id, function, line, errno, errstr); 170 } 171 #endif 172 173 /* Don't go through full error handling during mount */ 174 save_error_info(fs_info); 175 if (sb->s_flags & MS_BORN) 176 btrfs_handle_error(fs_info); 177 } 178 179 #ifdef CONFIG_PRINTK 180 static const char * const logtypes[] = { 181 "emergency", 182 "alert", 183 "critical", 184 "error", 185 "warning", 186 "notice", 187 "info", 188 "debug", 189 }; 190 191 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...) 192 { 193 struct super_block *sb = fs_info->sb; 194 char lvl[4]; 195 struct va_format vaf; 196 va_list args; 197 const char *type = logtypes[4]; 198 int kern_level; 199 200 va_start(args, fmt); 201 202 kern_level = printk_get_level(fmt); 203 if (kern_level) { 204 size_t size = printk_skip_level(fmt) - fmt; 205 memcpy(lvl, fmt, size); 206 lvl[size] = '\0'; 207 fmt += size; 208 type = logtypes[kern_level - '0']; 209 } else 210 *lvl = '\0'; 211 212 vaf.fmt = fmt; 213 vaf.va = &args; 214 215 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf); 216 217 va_end(args); 218 } 219 #endif 220 221 /* 222 * We only mark the transaction aborted and then set the file system read-only. 223 * This will prevent new transactions from starting or trying to join this 224 * one. 225 * 226 * This means that error recovery at the call site is limited to freeing 227 * any local memory allocations and passing the error code up without 228 * further cleanup. The transaction should complete as it normally would 229 * in the call path but will return -EIO. 230 * 231 * We'll complete the cleanup in btrfs_end_transaction and 232 * btrfs_commit_transaction. 233 */ 234 __cold 235 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 236 struct btrfs_root *root, const char *function, 237 unsigned int line, int errno) 238 { 239 trans->aborted = errno; 240 /* Nothing used. The other threads that have joined this 241 * transaction may be able to continue. */ 242 if (!trans->blocks_used && list_empty(&trans->new_bgs)) { 243 const char *errstr; 244 245 errstr = btrfs_decode_error(errno); 246 btrfs_warn(root->fs_info, 247 "%s:%d: Aborting unused transaction(%s).", 248 function, line, errstr); 249 return; 250 } 251 ACCESS_ONCE(trans->transaction->aborted) = errno; 252 /* Wake up anybody who may be waiting on this transaction */ 253 wake_up(&root->fs_info->transaction_wait); 254 wake_up(&root->fs_info->transaction_blocked_wait); 255 __btrfs_std_error(root->fs_info, function, line, errno, NULL); 256 } 257 /* 258 * __btrfs_panic decodes unexpected, fatal errors from the caller, 259 * issues an alert, and either panics or BUGs, depending on mount options. 260 */ 261 __cold 262 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, 263 unsigned int line, int errno, const char *fmt, ...) 264 { 265 char *s_id = "<unknown>"; 266 const char *errstr; 267 struct va_format vaf = { .fmt = fmt }; 268 va_list args; 269 270 if (fs_info) 271 s_id = fs_info->sb->s_id; 272 273 va_start(args, fmt); 274 vaf.va = &args; 275 276 errstr = btrfs_decode_error(errno); 277 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR)) 278 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n", 279 s_id, function, line, &vaf, errno, errstr); 280 281 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)", 282 function, line, &vaf, errno, errstr); 283 va_end(args); 284 /* Caller calls BUG() */ 285 } 286 287 static void btrfs_put_super(struct super_block *sb) 288 { 289 close_ctree(btrfs_sb(sb)->tree_root); 290 } 291 292 enum { 293 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, 294 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, 295 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, 296 Opt_compress_type, Opt_compress_force, Opt_compress_force_type, 297 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, 298 Opt_space_cache, Opt_space_cache_version, Opt_clear_cache, 299 Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid, 300 Opt_defrag, Opt_inode_cache, Opt_no_space_cache, Opt_recovery, 301 Opt_skip_balance, Opt_check_integrity, 302 Opt_check_integrity_including_extent_data, 303 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree, 304 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard, 305 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow, 306 Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot, 307 Opt_nologreplay, Opt_norecovery, 308 #ifdef CONFIG_BTRFS_DEBUG 309 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all, 310 #endif 311 Opt_err, 312 }; 313 314 static const match_table_t tokens = { 315 {Opt_degraded, "degraded"}, 316 {Opt_subvol, "subvol=%s"}, 317 {Opt_subvolid, "subvolid=%s"}, 318 {Opt_device, "device=%s"}, 319 {Opt_nodatasum, "nodatasum"}, 320 {Opt_datasum, "datasum"}, 321 {Opt_nodatacow, "nodatacow"}, 322 {Opt_datacow, "datacow"}, 323 {Opt_nobarrier, "nobarrier"}, 324 {Opt_barrier, "barrier"}, 325 {Opt_max_inline, "max_inline=%s"}, 326 {Opt_alloc_start, "alloc_start=%s"}, 327 {Opt_thread_pool, "thread_pool=%d"}, 328 {Opt_compress, "compress"}, 329 {Opt_compress_type, "compress=%s"}, 330 {Opt_compress_force, "compress-force"}, 331 {Opt_compress_force_type, "compress-force=%s"}, 332 {Opt_ssd, "ssd"}, 333 {Opt_ssd_spread, "ssd_spread"}, 334 {Opt_nossd, "nossd"}, 335 {Opt_acl, "acl"}, 336 {Opt_noacl, "noacl"}, 337 {Opt_notreelog, "notreelog"}, 338 {Opt_treelog, "treelog"}, 339 {Opt_nologreplay, "nologreplay"}, 340 {Opt_norecovery, "norecovery"}, 341 {Opt_flushoncommit, "flushoncommit"}, 342 {Opt_noflushoncommit, "noflushoncommit"}, 343 {Opt_ratio, "metadata_ratio=%d"}, 344 {Opt_discard, "discard"}, 345 {Opt_nodiscard, "nodiscard"}, 346 {Opt_space_cache, "space_cache"}, 347 {Opt_space_cache_version, "space_cache=%s"}, 348 {Opt_clear_cache, "clear_cache"}, 349 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, 350 {Opt_enospc_debug, "enospc_debug"}, 351 {Opt_noenospc_debug, "noenospc_debug"}, 352 {Opt_subvolrootid, "subvolrootid=%d"}, 353 {Opt_defrag, "autodefrag"}, 354 {Opt_nodefrag, "noautodefrag"}, 355 {Opt_inode_cache, "inode_cache"}, 356 {Opt_noinode_cache, "noinode_cache"}, 357 {Opt_no_space_cache, "nospace_cache"}, 358 {Opt_recovery, "recovery"}, /* deprecated */ 359 {Opt_usebackuproot, "usebackuproot"}, 360 {Opt_skip_balance, "skip_balance"}, 361 {Opt_check_integrity, "check_int"}, 362 {Opt_check_integrity_including_extent_data, "check_int_data"}, 363 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"}, 364 {Opt_rescan_uuid_tree, "rescan_uuid_tree"}, 365 {Opt_fatal_errors, "fatal_errors=%s"}, 366 {Opt_commit_interval, "commit=%d"}, 367 #ifdef CONFIG_BTRFS_DEBUG 368 {Opt_fragment_data, "fragment=data"}, 369 {Opt_fragment_metadata, "fragment=metadata"}, 370 {Opt_fragment_all, "fragment=all"}, 371 #endif 372 {Opt_err, NULL}, 373 }; 374 375 /* 376 * Regular mount options parser. Everything that is needed only when 377 * reading in a new superblock is parsed here. 378 * XXX JDM: This needs to be cleaned up for remount. 379 */ 380 int btrfs_parse_options(struct btrfs_root *root, char *options, 381 unsigned long new_flags) 382 { 383 struct btrfs_fs_info *info = root->fs_info; 384 substring_t args[MAX_OPT_ARGS]; 385 char *p, *num, *orig = NULL; 386 u64 cache_gen; 387 int intarg; 388 int ret = 0; 389 char *compress_type; 390 bool compress_force = false; 391 enum btrfs_compression_type saved_compress_type; 392 bool saved_compress_force; 393 int no_compress = 0; 394 395 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); 396 if (btrfs_fs_compat_ro(root->fs_info, FREE_SPACE_TREE)) 397 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE); 398 else if (cache_gen) 399 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 400 401 /* 402 * Even the options are empty, we still need to do extra check 403 * against new flags 404 */ 405 if (!options) 406 goto check; 407 408 /* 409 * strsep changes the string, duplicate it because parse_options 410 * gets called twice 411 */ 412 options = kstrdup(options, GFP_NOFS); 413 if (!options) 414 return -ENOMEM; 415 416 orig = options; 417 418 while ((p = strsep(&options, ",")) != NULL) { 419 int token; 420 if (!*p) 421 continue; 422 423 token = match_token(p, tokens, args); 424 switch (token) { 425 case Opt_degraded: 426 btrfs_info(root->fs_info, "allowing degraded mounts"); 427 btrfs_set_opt(info->mount_opt, DEGRADED); 428 break; 429 case Opt_subvol: 430 case Opt_subvolid: 431 case Opt_subvolrootid: 432 case Opt_device: 433 /* 434 * These are parsed by btrfs_parse_early_options 435 * and can be happily ignored here. 436 */ 437 break; 438 case Opt_nodatasum: 439 btrfs_set_and_info(root, NODATASUM, 440 "setting nodatasum"); 441 break; 442 case Opt_datasum: 443 if (btrfs_test_opt(root, NODATASUM)) { 444 if (btrfs_test_opt(root, NODATACOW)) 445 btrfs_info(root->fs_info, "setting datasum, datacow enabled"); 446 else 447 btrfs_info(root->fs_info, "setting datasum"); 448 } 449 btrfs_clear_opt(info->mount_opt, NODATACOW); 450 btrfs_clear_opt(info->mount_opt, NODATASUM); 451 break; 452 case Opt_nodatacow: 453 if (!btrfs_test_opt(root, NODATACOW)) { 454 if (!btrfs_test_opt(root, COMPRESS) || 455 !btrfs_test_opt(root, FORCE_COMPRESS)) { 456 btrfs_info(root->fs_info, 457 "setting nodatacow, compression disabled"); 458 } else { 459 btrfs_info(root->fs_info, "setting nodatacow"); 460 } 461 } 462 btrfs_clear_opt(info->mount_opt, COMPRESS); 463 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 464 btrfs_set_opt(info->mount_opt, NODATACOW); 465 btrfs_set_opt(info->mount_opt, NODATASUM); 466 break; 467 case Opt_datacow: 468 btrfs_clear_and_info(root, NODATACOW, 469 "setting datacow"); 470 break; 471 case Opt_compress_force: 472 case Opt_compress_force_type: 473 compress_force = true; 474 /* Fallthrough */ 475 case Opt_compress: 476 case Opt_compress_type: 477 saved_compress_type = btrfs_test_opt(root, COMPRESS) ? 478 info->compress_type : BTRFS_COMPRESS_NONE; 479 saved_compress_force = 480 btrfs_test_opt(root, FORCE_COMPRESS); 481 if (token == Opt_compress || 482 token == Opt_compress_force || 483 strcmp(args[0].from, "zlib") == 0) { 484 compress_type = "zlib"; 485 info->compress_type = BTRFS_COMPRESS_ZLIB; 486 btrfs_set_opt(info->mount_opt, COMPRESS); 487 btrfs_clear_opt(info->mount_opt, NODATACOW); 488 btrfs_clear_opt(info->mount_opt, NODATASUM); 489 no_compress = 0; 490 } else if (strcmp(args[0].from, "lzo") == 0) { 491 compress_type = "lzo"; 492 info->compress_type = BTRFS_COMPRESS_LZO; 493 btrfs_set_opt(info->mount_opt, COMPRESS); 494 btrfs_clear_opt(info->mount_opt, NODATACOW); 495 btrfs_clear_opt(info->mount_opt, NODATASUM); 496 btrfs_set_fs_incompat(info, COMPRESS_LZO); 497 no_compress = 0; 498 } else if (strncmp(args[0].from, "no", 2) == 0) { 499 compress_type = "no"; 500 btrfs_clear_opt(info->mount_opt, COMPRESS); 501 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 502 compress_force = false; 503 no_compress++; 504 } else { 505 ret = -EINVAL; 506 goto out; 507 } 508 509 if (compress_force) { 510 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); 511 } else { 512 /* 513 * If we remount from compress-force=xxx to 514 * compress=xxx, we need clear FORCE_COMPRESS 515 * flag, otherwise, there is no way for users 516 * to disable forcible compression separately. 517 */ 518 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 519 } 520 if ((btrfs_test_opt(root, COMPRESS) && 521 (info->compress_type != saved_compress_type || 522 compress_force != saved_compress_force)) || 523 (!btrfs_test_opt(root, COMPRESS) && 524 no_compress == 1)) { 525 btrfs_info(root->fs_info, 526 "%s %s compression", 527 (compress_force) ? "force" : "use", 528 compress_type); 529 } 530 compress_force = false; 531 break; 532 case Opt_ssd: 533 btrfs_set_and_info(root, SSD, 534 "use ssd allocation scheme"); 535 break; 536 case Opt_ssd_spread: 537 btrfs_set_and_info(root, SSD_SPREAD, 538 "use spread ssd allocation scheme"); 539 btrfs_set_opt(info->mount_opt, SSD); 540 break; 541 case Opt_nossd: 542 btrfs_set_and_info(root, NOSSD, 543 "not using ssd allocation scheme"); 544 btrfs_clear_opt(info->mount_opt, SSD); 545 break; 546 case Opt_barrier: 547 btrfs_clear_and_info(root, NOBARRIER, 548 "turning on barriers"); 549 break; 550 case Opt_nobarrier: 551 btrfs_set_and_info(root, NOBARRIER, 552 "turning off barriers"); 553 break; 554 case Opt_thread_pool: 555 ret = match_int(&args[0], &intarg); 556 if (ret) { 557 goto out; 558 } else if (intarg > 0) { 559 info->thread_pool_size = intarg; 560 } else { 561 ret = -EINVAL; 562 goto out; 563 } 564 break; 565 case Opt_max_inline: 566 num = match_strdup(&args[0]); 567 if (num) { 568 info->max_inline = memparse(num, NULL); 569 kfree(num); 570 571 if (info->max_inline) { 572 info->max_inline = min_t(u64, 573 info->max_inline, 574 root->sectorsize); 575 } 576 btrfs_info(root->fs_info, "max_inline at %llu", 577 info->max_inline); 578 } else { 579 ret = -ENOMEM; 580 goto out; 581 } 582 break; 583 case Opt_alloc_start: 584 num = match_strdup(&args[0]); 585 if (num) { 586 mutex_lock(&info->chunk_mutex); 587 info->alloc_start = memparse(num, NULL); 588 mutex_unlock(&info->chunk_mutex); 589 kfree(num); 590 btrfs_info(root->fs_info, "allocations start at %llu", 591 info->alloc_start); 592 } else { 593 ret = -ENOMEM; 594 goto out; 595 } 596 break; 597 case Opt_acl: 598 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 599 root->fs_info->sb->s_flags |= MS_POSIXACL; 600 break; 601 #else 602 btrfs_err(root->fs_info, 603 "support for ACL not compiled in!"); 604 ret = -EINVAL; 605 goto out; 606 #endif 607 case Opt_noacl: 608 root->fs_info->sb->s_flags &= ~MS_POSIXACL; 609 break; 610 case Opt_notreelog: 611 btrfs_set_and_info(root, NOTREELOG, 612 "disabling tree log"); 613 break; 614 case Opt_treelog: 615 btrfs_clear_and_info(root, NOTREELOG, 616 "enabling tree log"); 617 break; 618 case Opt_norecovery: 619 case Opt_nologreplay: 620 btrfs_set_and_info(root, NOLOGREPLAY, 621 "disabling log replay at mount time"); 622 break; 623 case Opt_flushoncommit: 624 btrfs_set_and_info(root, FLUSHONCOMMIT, 625 "turning on flush-on-commit"); 626 break; 627 case Opt_noflushoncommit: 628 btrfs_clear_and_info(root, FLUSHONCOMMIT, 629 "turning off flush-on-commit"); 630 break; 631 case Opt_ratio: 632 ret = match_int(&args[0], &intarg); 633 if (ret) { 634 goto out; 635 } else if (intarg >= 0) { 636 info->metadata_ratio = intarg; 637 btrfs_info(root->fs_info, "metadata ratio %d", 638 info->metadata_ratio); 639 } else { 640 ret = -EINVAL; 641 goto out; 642 } 643 break; 644 case Opt_discard: 645 btrfs_set_and_info(root, DISCARD, 646 "turning on discard"); 647 break; 648 case Opt_nodiscard: 649 btrfs_clear_and_info(root, DISCARD, 650 "turning off discard"); 651 break; 652 case Opt_space_cache: 653 case Opt_space_cache_version: 654 if (token == Opt_space_cache || 655 strcmp(args[0].from, "v1") == 0) { 656 btrfs_clear_opt(root->fs_info->mount_opt, 657 FREE_SPACE_TREE); 658 btrfs_set_and_info(root, SPACE_CACHE, 659 "enabling disk space caching"); 660 } else if (strcmp(args[0].from, "v2") == 0) { 661 btrfs_clear_opt(root->fs_info->mount_opt, 662 SPACE_CACHE); 663 btrfs_set_and_info(root, FREE_SPACE_TREE, 664 "enabling free space tree"); 665 } else { 666 ret = -EINVAL; 667 goto out; 668 } 669 break; 670 case Opt_rescan_uuid_tree: 671 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE); 672 break; 673 case Opt_no_space_cache: 674 if (btrfs_test_opt(root, SPACE_CACHE)) { 675 btrfs_clear_and_info(root, SPACE_CACHE, 676 "disabling disk space caching"); 677 } 678 if (btrfs_test_opt(root, FREE_SPACE_TREE)) { 679 btrfs_clear_and_info(root, FREE_SPACE_TREE, 680 "disabling free space tree"); 681 } 682 break; 683 case Opt_inode_cache: 684 btrfs_set_pending_and_info(info, INODE_MAP_CACHE, 685 "enabling inode map caching"); 686 break; 687 case Opt_noinode_cache: 688 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE, 689 "disabling inode map caching"); 690 break; 691 case Opt_clear_cache: 692 btrfs_set_and_info(root, CLEAR_CACHE, 693 "force clearing of disk cache"); 694 break; 695 case Opt_user_subvol_rm_allowed: 696 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 697 break; 698 case Opt_enospc_debug: 699 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 700 break; 701 case Opt_noenospc_debug: 702 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG); 703 break; 704 case Opt_defrag: 705 btrfs_set_and_info(root, AUTO_DEFRAG, 706 "enabling auto defrag"); 707 break; 708 case Opt_nodefrag: 709 btrfs_clear_and_info(root, AUTO_DEFRAG, 710 "disabling auto defrag"); 711 break; 712 case Opt_recovery: 713 btrfs_warn(root->fs_info, 714 "'recovery' is deprecated, use 'usebackuproot' instead"); 715 case Opt_usebackuproot: 716 btrfs_info(root->fs_info, 717 "trying to use backup root at mount time"); 718 btrfs_set_opt(info->mount_opt, USEBACKUPROOT); 719 break; 720 case Opt_skip_balance: 721 btrfs_set_opt(info->mount_opt, SKIP_BALANCE); 722 break; 723 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 724 case Opt_check_integrity_including_extent_data: 725 btrfs_info(root->fs_info, 726 "enabling check integrity including extent data"); 727 btrfs_set_opt(info->mount_opt, 728 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); 729 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 730 break; 731 case Opt_check_integrity: 732 btrfs_info(root->fs_info, "enabling check integrity"); 733 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 734 break; 735 case Opt_check_integrity_print_mask: 736 ret = match_int(&args[0], &intarg); 737 if (ret) { 738 goto out; 739 } else if (intarg >= 0) { 740 info->check_integrity_print_mask = intarg; 741 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x", 742 info->check_integrity_print_mask); 743 } else { 744 ret = -EINVAL; 745 goto out; 746 } 747 break; 748 #else 749 case Opt_check_integrity_including_extent_data: 750 case Opt_check_integrity: 751 case Opt_check_integrity_print_mask: 752 btrfs_err(root->fs_info, 753 "support for check_integrity* not compiled in!"); 754 ret = -EINVAL; 755 goto out; 756 #endif 757 case Opt_fatal_errors: 758 if (strcmp(args[0].from, "panic") == 0) 759 btrfs_set_opt(info->mount_opt, 760 PANIC_ON_FATAL_ERROR); 761 else if (strcmp(args[0].from, "bug") == 0) 762 btrfs_clear_opt(info->mount_opt, 763 PANIC_ON_FATAL_ERROR); 764 else { 765 ret = -EINVAL; 766 goto out; 767 } 768 break; 769 case Opt_commit_interval: 770 intarg = 0; 771 ret = match_int(&args[0], &intarg); 772 if (ret < 0) { 773 btrfs_err(root->fs_info, "invalid commit interval"); 774 ret = -EINVAL; 775 goto out; 776 } 777 if (intarg > 0) { 778 if (intarg > 300) { 779 btrfs_warn(root->fs_info, "excessive commit interval %d", 780 intarg); 781 } 782 info->commit_interval = intarg; 783 } else { 784 btrfs_info(root->fs_info, "using default commit interval %ds", 785 BTRFS_DEFAULT_COMMIT_INTERVAL); 786 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL; 787 } 788 break; 789 #ifdef CONFIG_BTRFS_DEBUG 790 case Opt_fragment_all: 791 btrfs_info(root->fs_info, "fragmenting all space"); 792 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 793 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA); 794 break; 795 case Opt_fragment_metadata: 796 btrfs_info(root->fs_info, "fragmenting metadata"); 797 btrfs_set_opt(info->mount_opt, 798 FRAGMENT_METADATA); 799 break; 800 case Opt_fragment_data: 801 btrfs_info(root->fs_info, "fragmenting data"); 802 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 803 break; 804 #endif 805 case Opt_err: 806 btrfs_info(root->fs_info, "unrecognized mount option '%s'", p); 807 ret = -EINVAL; 808 goto out; 809 default: 810 break; 811 } 812 } 813 check: 814 /* 815 * Extra check for current option against current flag 816 */ 817 if (btrfs_test_opt(root, NOLOGREPLAY) && !(new_flags & MS_RDONLY)) { 818 btrfs_err(root->fs_info, 819 "nologreplay must be used with ro mount option"); 820 ret = -EINVAL; 821 } 822 out: 823 if (btrfs_fs_compat_ro(root->fs_info, FREE_SPACE_TREE) && 824 !btrfs_test_opt(root, FREE_SPACE_TREE) && 825 !btrfs_test_opt(root, CLEAR_CACHE)) { 826 btrfs_err(root->fs_info, "cannot disable free space tree"); 827 ret = -EINVAL; 828 829 } 830 if (!ret && btrfs_test_opt(root, SPACE_CACHE)) 831 btrfs_info(root->fs_info, "disk space caching is enabled"); 832 if (!ret && btrfs_test_opt(root, FREE_SPACE_TREE)) 833 btrfs_info(root->fs_info, "using free space tree"); 834 kfree(orig); 835 return ret; 836 } 837 838 /* 839 * Parse mount options that are required early in the mount process. 840 * 841 * All other options will be parsed on much later in the mount process and 842 * only when we need to allocate a new super block. 843 */ 844 static int btrfs_parse_early_options(const char *options, fmode_t flags, 845 void *holder, char **subvol_name, u64 *subvol_objectid, 846 struct btrfs_fs_devices **fs_devices) 847 { 848 substring_t args[MAX_OPT_ARGS]; 849 char *device_name, *opts, *orig, *p; 850 char *num = NULL; 851 int error = 0; 852 853 if (!options) 854 return 0; 855 856 /* 857 * strsep changes the string, duplicate it because parse_options 858 * gets called twice 859 */ 860 opts = kstrdup(options, GFP_KERNEL); 861 if (!opts) 862 return -ENOMEM; 863 orig = opts; 864 865 while ((p = strsep(&opts, ",")) != NULL) { 866 int token; 867 if (!*p) 868 continue; 869 870 token = match_token(p, tokens, args); 871 switch (token) { 872 case Opt_subvol: 873 kfree(*subvol_name); 874 *subvol_name = match_strdup(&args[0]); 875 if (!*subvol_name) { 876 error = -ENOMEM; 877 goto out; 878 } 879 break; 880 case Opt_subvolid: 881 num = match_strdup(&args[0]); 882 if (num) { 883 *subvol_objectid = memparse(num, NULL); 884 kfree(num); 885 /* we want the original fs_tree */ 886 if (!*subvol_objectid) 887 *subvol_objectid = 888 BTRFS_FS_TREE_OBJECTID; 889 } else { 890 error = -EINVAL; 891 goto out; 892 } 893 break; 894 case Opt_subvolrootid: 895 printk(KERN_WARNING 896 "BTRFS: 'subvolrootid' mount option is deprecated and has " 897 "no effect\n"); 898 break; 899 case Opt_device: 900 device_name = match_strdup(&args[0]); 901 if (!device_name) { 902 error = -ENOMEM; 903 goto out; 904 } 905 error = btrfs_scan_one_device(device_name, 906 flags, holder, fs_devices); 907 kfree(device_name); 908 if (error) 909 goto out; 910 break; 911 default: 912 break; 913 } 914 } 915 916 out: 917 kfree(orig); 918 return error; 919 } 920 921 static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, 922 u64 subvol_objectid) 923 { 924 struct btrfs_root *root = fs_info->tree_root; 925 struct btrfs_root *fs_root; 926 struct btrfs_root_ref *root_ref; 927 struct btrfs_inode_ref *inode_ref; 928 struct btrfs_key key; 929 struct btrfs_path *path = NULL; 930 char *name = NULL, *ptr; 931 u64 dirid; 932 int len; 933 int ret; 934 935 path = btrfs_alloc_path(); 936 if (!path) { 937 ret = -ENOMEM; 938 goto err; 939 } 940 path->leave_spinning = 1; 941 942 name = kmalloc(PATH_MAX, GFP_NOFS); 943 if (!name) { 944 ret = -ENOMEM; 945 goto err; 946 } 947 ptr = name + PATH_MAX - 1; 948 ptr[0] = '\0'; 949 950 /* 951 * Walk up the subvolume trees in the tree of tree roots by root 952 * backrefs until we hit the top-level subvolume. 953 */ 954 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) { 955 key.objectid = subvol_objectid; 956 key.type = BTRFS_ROOT_BACKREF_KEY; 957 key.offset = (u64)-1; 958 959 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 960 if (ret < 0) { 961 goto err; 962 } else if (ret > 0) { 963 ret = btrfs_previous_item(root, path, subvol_objectid, 964 BTRFS_ROOT_BACKREF_KEY); 965 if (ret < 0) { 966 goto err; 967 } else if (ret > 0) { 968 ret = -ENOENT; 969 goto err; 970 } 971 } 972 973 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 974 subvol_objectid = key.offset; 975 976 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 977 struct btrfs_root_ref); 978 len = btrfs_root_ref_name_len(path->nodes[0], root_ref); 979 ptr -= len + 1; 980 if (ptr < name) { 981 ret = -ENAMETOOLONG; 982 goto err; 983 } 984 read_extent_buffer(path->nodes[0], ptr + 1, 985 (unsigned long)(root_ref + 1), len); 986 ptr[0] = '/'; 987 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref); 988 btrfs_release_path(path); 989 990 key.objectid = subvol_objectid; 991 key.type = BTRFS_ROOT_ITEM_KEY; 992 key.offset = (u64)-1; 993 fs_root = btrfs_read_fs_root_no_name(fs_info, &key); 994 if (IS_ERR(fs_root)) { 995 ret = PTR_ERR(fs_root); 996 goto err; 997 } 998 999 /* 1000 * Walk up the filesystem tree by inode refs until we hit the 1001 * root directory. 1002 */ 1003 while (dirid != BTRFS_FIRST_FREE_OBJECTID) { 1004 key.objectid = dirid; 1005 key.type = BTRFS_INODE_REF_KEY; 1006 key.offset = (u64)-1; 1007 1008 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); 1009 if (ret < 0) { 1010 goto err; 1011 } else if (ret > 0) { 1012 ret = btrfs_previous_item(fs_root, path, dirid, 1013 BTRFS_INODE_REF_KEY); 1014 if (ret < 0) { 1015 goto err; 1016 } else if (ret > 0) { 1017 ret = -ENOENT; 1018 goto err; 1019 } 1020 } 1021 1022 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 1023 dirid = key.offset; 1024 1025 inode_ref = btrfs_item_ptr(path->nodes[0], 1026 path->slots[0], 1027 struct btrfs_inode_ref); 1028 len = btrfs_inode_ref_name_len(path->nodes[0], 1029 inode_ref); 1030 ptr -= len + 1; 1031 if (ptr < name) { 1032 ret = -ENAMETOOLONG; 1033 goto err; 1034 } 1035 read_extent_buffer(path->nodes[0], ptr + 1, 1036 (unsigned long)(inode_ref + 1), len); 1037 ptr[0] = '/'; 1038 btrfs_release_path(path); 1039 } 1040 } 1041 1042 btrfs_free_path(path); 1043 if (ptr == name + PATH_MAX - 1) { 1044 name[0] = '/'; 1045 name[1] = '\0'; 1046 } else { 1047 memmove(name, ptr, name + PATH_MAX - ptr); 1048 } 1049 return name; 1050 1051 err: 1052 btrfs_free_path(path); 1053 kfree(name); 1054 return ERR_PTR(ret); 1055 } 1056 1057 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid) 1058 { 1059 struct btrfs_root *root = fs_info->tree_root; 1060 struct btrfs_dir_item *di; 1061 struct btrfs_path *path; 1062 struct btrfs_key location; 1063 u64 dir_id; 1064 1065 path = btrfs_alloc_path(); 1066 if (!path) 1067 return -ENOMEM; 1068 path->leave_spinning = 1; 1069 1070 /* 1071 * Find the "default" dir item which points to the root item that we 1072 * will mount by default if we haven't been given a specific subvolume 1073 * to mount. 1074 */ 1075 dir_id = btrfs_super_root_dir(fs_info->super_copy); 1076 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 1077 if (IS_ERR(di)) { 1078 btrfs_free_path(path); 1079 return PTR_ERR(di); 1080 } 1081 if (!di) { 1082 /* 1083 * Ok the default dir item isn't there. This is weird since 1084 * it's always been there, but don't freak out, just try and 1085 * mount the top-level subvolume. 1086 */ 1087 btrfs_free_path(path); 1088 *objectid = BTRFS_FS_TREE_OBJECTID; 1089 return 0; 1090 } 1091 1092 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 1093 btrfs_free_path(path); 1094 *objectid = location.objectid; 1095 return 0; 1096 } 1097 1098 static int btrfs_fill_super(struct super_block *sb, 1099 struct btrfs_fs_devices *fs_devices, 1100 void *data, int silent) 1101 { 1102 struct inode *inode; 1103 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1104 struct btrfs_key key; 1105 int err; 1106 1107 sb->s_maxbytes = MAX_LFS_FILESIZE; 1108 sb->s_magic = BTRFS_SUPER_MAGIC; 1109 sb->s_op = &btrfs_super_ops; 1110 sb->s_d_op = &btrfs_dentry_operations; 1111 sb->s_export_op = &btrfs_export_ops; 1112 sb->s_xattr = btrfs_xattr_handlers; 1113 sb->s_time_gran = 1; 1114 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 1115 sb->s_flags |= MS_POSIXACL; 1116 #endif 1117 sb->s_flags |= MS_I_VERSION; 1118 sb->s_iflags |= SB_I_CGROUPWB; 1119 err = open_ctree(sb, fs_devices, (char *)data); 1120 if (err) { 1121 printk(KERN_ERR "BTRFS: open_ctree failed\n"); 1122 return err; 1123 } 1124 1125 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 1126 key.type = BTRFS_INODE_ITEM_KEY; 1127 key.offset = 0; 1128 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL); 1129 if (IS_ERR(inode)) { 1130 err = PTR_ERR(inode); 1131 goto fail_close; 1132 } 1133 1134 sb->s_root = d_make_root(inode); 1135 if (!sb->s_root) { 1136 err = -ENOMEM; 1137 goto fail_close; 1138 } 1139 1140 save_mount_options(sb, data); 1141 cleancache_init_fs(sb); 1142 sb->s_flags |= MS_ACTIVE; 1143 return 0; 1144 1145 fail_close: 1146 close_ctree(fs_info->tree_root); 1147 return err; 1148 } 1149 1150 int btrfs_sync_fs(struct super_block *sb, int wait) 1151 { 1152 struct btrfs_trans_handle *trans; 1153 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1154 struct btrfs_root *root = fs_info->tree_root; 1155 1156 trace_btrfs_sync_fs(wait); 1157 1158 if (!wait) { 1159 filemap_flush(fs_info->btree_inode->i_mapping); 1160 return 0; 1161 } 1162 1163 btrfs_wait_ordered_roots(fs_info, -1); 1164 1165 trans = btrfs_attach_transaction_barrier(root); 1166 if (IS_ERR(trans)) { 1167 /* no transaction, don't bother */ 1168 if (PTR_ERR(trans) == -ENOENT) { 1169 /* 1170 * Exit unless we have some pending changes 1171 * that need to go through commit 1172 */ 1173 if (fs_info->pending_changes == 0) 1174 return 0; 1175 /* 1176 * A non-blocking test if the fs is frozen. We must not 1177 * start a new transaction here otherwise a deadlock 1178 * happens. The pending operations are delayed to the 1179 * next commit after thawing. 1180 */ 1181 if (__sb_start_write(sb, SB_FREEZE_WRITE, false)) 1182 __sb_end_write(sb, SB_FREEZE_WRITE); 1183 else 1184 return 0; 1185 trans = btrfs_start_transaction(root, 0); 1186 } 1187 if (IS_ERR(trans)) 1188 return PTR_ERR(trans); 1189 } 1190 return btrfs_commit_transaction(trans, root); 1191 } 1192 1193 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) 1194 { 1195 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); 1196 struct btrfs_root *root = info->tree_root; 1197 char *compress_type; 1198 1199 if (btrfs_test_opt(root, DEGRADED)) 1200 seq_puts(seq, ",degraded"); 1201 if (btrfs_test_opt(root, NODATASUM)) 1202 seq_puts(seq, ",nodatasum"); 1203 if (btrfs_test_opt(root, NODATACOW)) 1204 seq_puts(seq, ",nodatacow"); 1205 if (btrfs_test_opt(root, NOBARRIER)) 1206 seq_puts(seq, ",nobarrier"); 1207 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) 1208 seq_printf(seq, ",max_inline=%llu", info->max_inline); 1209 if (info->alloc_start != 0) 1210 seq_printf(seq, ",alloc_start=%llu", info->alloc_start); 1211 if (info->thread_pool_size != min_t(unsigned long, 1212 num_online_cpus() + 2, 8)) 1213 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 1214 if (btrfs_test_opt(root, COMPRESS)) { 1215 if (info->compress_type == BTRFS_COMPRESS_ZLIB) 1216 compress_type = "zlib"; 1217 else 1218 compress_type = "lzo"; 1219 if (btrfs_test_opt(root, FORCE_COMPRESS)) 1220 seq_printf(seq, ",compress-force=%s", compress_type); 1221 else 1222 seq_printf(seq, ",compress=%s", compress_type); 1223 } 1224 if (btrfs_test_opt(root, NOSSD)) 1225 seq_puts(seq, ",nossd"); 1226 if (btrfs_test_opt(root, SSD_SPREAD)) 1227 seq_puts(seq, ",ssd_spread"); 1228 else if (btrfs_test_opt(root, SSD)) 1229 seq_puts(seq, ",ssd"); 1230 if (btrfs_test_opt(root, NOTREELOG)) 1231 seq_puts(seq, ",notreelog"); 1232 if (btrfs_test_opt(root, NOLOGREPLAY)) 1233 seq_puts(seq, ",nologreplay"); 1234 if (btrfs_test_opt(root, FLUSHONCOMMIT)) 1235 seq_puts(seq, ",flushoncommit"); 1236 if (btrfs_test_opt(root, DISCARD)) 1237 seq_puts(seq, ",discard"); 1238 if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) 1239 seq_puts(seq, ",noacl"); 1240 if (btrfs_test_opt(root, SPACE_CACHE)) 1241 seq_puts(seq, ",space_cache"); 1242 else if (btrfs_test_opt(root, FREE_SPACE_TREE)) 1243 seq_puts(seq, ",space_cache=v2"); 1244 else 1245 seq_puts(seq, ",nospace_cache"); 1246 if (btrfs_test_opt(root, RESCAN_UUID_TREE)) 1247 seq_puts(seq, ",rescan_uuid_tree"); 1248 if (btrfs_test_opt(root, CLEAR_CACHE)) 1249 seq_puts(seq, ",clear_cache"); 1250 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 1251 seq_puts(seq, ",user_subvol_rm_allowed"); 1252 if (btrfs_test_opt(root, ENOSPC_DEBUG)) 1253 seq_puts(seq, ",enospc_debug"); 1254 if (btrfs_test_opt(root, AUTO_DEFRAG)) 1255 seq_puts(seq, ",autodefrag"); 1256 if (btrfs_test_opt(root, INODE_MAP_CACHE)) 1257 seq_puts(seq, ",inode_cache"); 1258 if (btrfs_test_opt(root, SKIP_BALANCE)) 1259 seq_puts(seq, ",skip_balance"); 1260 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 1261 if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA)) 1262 seq_puts(seq, ",check_int_data"); 1263 else if (btrfs_test_opt(root, CHECK_INTEGRITY)) 1264 seq_puts(seq, ",check_int"); 1265 if (info->check_integrity_print_mask) 1266 seq_printf(seq, ",check_int_print_mask=%d", 1267 info->check_integrity_print_mask); 1268 #endif 1269 if (info->metadata_ratio) 1270 seq_printf(seq, ",metadata_ratio=%d", 1271 info->metadata_ratio); 1272 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR)) 1273 seq_puts(seq, ",fatal_errors=panic"); 1274 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) 1275 seq_printf(seq, ",commit=%d", info->commit_interval); 1276 #ifdef CONFIG_BTRFS_DEBUG 1277 if (btrfs_test_opt(root, FRAGMENT_DATA)) 1278 seq_puts(seq, ",fragment=data"); 1279 if (btrfs_test_opt(root, FRAGMENT_METADATA)) 1280 seq_puts(seq, ",fragment=metadata"); 1281 #endif 1282 seq_printf(seq, ",subvolid=%llu", 1283 BTRFS_I(d_inode(dentry))->root->root_key.objectid); 1284 seq_puts(seq, ",subvol="); 1285 seq_dentry(seq, dentry, " \t\n\\"); 1286 return 0; 1287 } 1288 1289 static int btrfs_test_super(struct super_block *s, void *data) 1290 { 1291 struct btrfs_fs_info *p = data; 1292 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1293 1294 return fs_info->fs_devices == p->fs_devices; 1295 } 1296 1297 static int btrfs_set_super(struct super_block *s, void *data) 1298 { 1299 int err = set_anon_super(s, data); 1300 if (!err) 1301 s->s_fs_info = data; 1302 return err; 1303 } 1304 1305 /* 1306 * subvolumes are identified by ino 256 1307 */ 1308 static inline int is_subvolume_inode(struct inode *inode) 1309 { 1310 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 1311 return 1; 1312 return 0; 1313 } 1314 1315 /* 1316 * This will add subvolid=0 to the argument string while removing any subvol= 1317 * and subvolid= arguments to make sure we get the top-level root for path 1318 * walking to the subvol we want. 1319 */ 1320 static char *setup_root_args(char *args) 1321 { 1322 char *buf, *dst, *sep; 1323 1324 if (!args) 1325 return kstrdup("subvolid=0", GFP_NOFS); 1326 1327 /* The worst case is that we add ",subvolid=0" to the end. */ 1328 buf = dst = kmalloc(strlen(args) + strlen(",subvolid=0") + 1, GFP_NOFS); 1329 if (!buf) 1330 return NULL; 1331 1332 while (1) { 1333 sep = strchrnul(args, ','); 1334 if (!strstarts(args, "subvol=") && 1335 !strstarts(args, "subvolid=")) { 1336 memcpy(dst, args, sep - args); 1337 dst += sep - args; 1338 *dst++ = ','; 1339 } 1340 if (*sep) 1341 args = sep + 1; 1342 else 1343 break; 1344 } 1345 strcpy(dst, "subvolid=0"); 1346 1347 return buf; 1348 } 1349 1350 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid, 1351 int flags, const char *device_name, 1352 char *data) 1353 { 1354 struct dentry *root; 1355 struct vfsmount *mnt = NULL; 1356 char *newargs; 1357 int ret; 1358 1359 newargs = setup_root_args(data); 1360 if (!newargs) { 1361 root = ERR_PTR(-ENOMEM); 1362 goto out; 1363 } 1364 1365 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs); 1366 if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) { 1367 if (flags & MS_RDONLY) { 1368 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, 1369 device_name, newargs); 1370 } else { 1371 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, 1372 device_name, newargs); 1373 if (IS_ERR(mnt)) { 1374 root = ERR_CAST(mnt); 1375 mnt = NULL; 1376 goto out; 1377 } 1378 1379 down_write(&mnt->mnt_sb->s_umount); 1380 ret = btrfs_remount(mnt->mnt_sb, &flags, NULL); 1381 up_write(&mnt->mnt_sb->s_umount); 1382 if (ret < 0) { 1383 root = ERR_PTR(ret); 1384 goto out; 1385 } 1386 } 1387 } 1388 if (IS_ERR(mnt)) { 1389 root = ERR_CAST(mnt); 1390 mnt = NULL; 1391 goto out; 1392 } 1393 1394 if (!subvol_name) { 1395 if (!subvol_objectid) { 1396 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb), 1397 &subvol_objectid); 1398 if (ret) { 1399 root = ERR_PTR(ret); 1400 goto out; 1401 } 1402 } 1403 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb), 1404 subvol_objectid); 1405 if (IS_ERR(subvol_name)) { 1406 root = ERR_CAST(subvol_name); 1407 subvol_name = NULL; 1408 goto out; 1409 } 1410 1411 } 1412 1413 root = mount_subtree(mnt, subvol_name); 1414 /* mount_subtree() drops our reference on the vfsmount. */ 1415 mnt = NULL; 1416 1417 if (!IS_ERR(root)) { 1418 struct super_block *s = root->d_sb; 1419 struct inode *root_inode = d_inode(root); 1420 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid; 1421 1422 ret = 0; 1423 if (!is_subvolume_inode(root_inode)) { 1424 pr_err("BTRFS: '%s' is not a valid subvolume\n", 1425 subvol_name); 1426 ret = -EINVAL; 1427 } 1428 if (subvol_objectid && root_objectid != subvol_objectid) { 1429 /* 1430 * This will also catch a race condition where a 1431 * subvolume which was passed by ID is renamed and 1432 * another subvolume is renamed over the old location. 1433 */ 1434 pr_err("BTRFS: subvol '%s' does not match subvolid %llu\n", 1435 subvol_name, subvol_objectid); 1436 ret = -EINVAL; 1437 } 1438 if (ret) { 1439 dput(root); 1440 root = ERR_PTR(ret); 1441 deactivate_locked_super(s); 1442 } 1443 } 1444 1445 out: 1446 mntput(mnt); 1447 kfree(newargs); 1448 kfree(subvol_name); 1449 return root; 1450 } 1451 1452 static int parse_security_options(char *orig_opts, 1453 struct security_mnt_opts *sec_opts) 1454 { 1455 char *secdata = NULL; 1456 int ret = 0; 1457 1458 secdata = alloc_secdata(); 1459 if (!secdata) 1460 return -ENOMEM; 1461 ret = security_sb_copy_data(orig_opts, secdata); 1462 if (ret) { 1463 free_secdata(secdata); 1464 return ret; 1465 } 1466 ret = security_sb_parse_opts_str(secdata, sec_opts); 1467 free_secdata(secdata); 1468 return ret; 1469 } 1470 1471 static int setup_security_options(struct btrfs_fs_info *fs_info, 1472 struct super_block *sb, 1473 struct security_mnt_opts *sec_opts) 1474 { 1475 int ret = 0; 1476 1477 /* 1478 * Call security_sb_set_mnt_opts() to check whether new sec_opts 1479 * is valid. 1480 */ 1481 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL); 1482 if (ret) 1483 return ret; 1484 1485 #ifdef CONFIG_SECURITY 1486 if (!fs_info->security_opts.num_mnt_opts) { 1487 /* first time security setup, copy sec_opts to fs_info */ 1488 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts)); 1489 } else { 1490 /* 1491 * Since SELinux(the only one supports security_mnt_opts) does 1492 * NOT support changing context during remount/mount same sb, 1493 * This must be the same or part of the same security options, 1494 * just free it. 1495 */ 1496 security_free_mnt_opts(sec_opts); 1497 } 1498 #endif 1499 return ret; 1500 } 1501 1502 /* 1503 * Find a superblock for the given device / mount point. 1504 * 1505 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 1506 * for multiple device setup. Make sure to keep it in sync. 1507 */ 1508 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 1509 const char *device_name, void *data) 1510 { 1511 struct block_device *bdev = NULL; 1512 struct super_block *s; 1513 struct btrfs_fs_devices *fs_devices = NULL; 1514 struct btrfs_fs_info *fs_info = NULL; 1515 struct security_mnt_opts new_sec_opts; 1516 fmode_t mode = FMODE_READ; 1517 char *subvol_name = NULL; 1518 u64 subvol_objectid = 0; 1519 int error = 0; 1520 1521 if (!(flags & MS_RDONLY)) 1522 mode |= FMODE_WRITE; 1523 1524 error = btrfs_parse_early_options(data, mode, fs_type, 1525 &subvol_name, &subvol_objectid, 1526 &fs_devices); 1527 if (error) { 1528 kfree(subvol_name); 1529 return ERR_PTR(error); 1530 } 1531 1532 if (subvol_name || subvol_objectid != BTRFS_FS_TREE_OBJECTID) { 1533 /* mount_subvol() will free subvol_name. */ 1534 return mount_subvol(subvol_name, subvol_objectid, flags, 1535 device_name, data); 1536 } 1537 1538 security_init_mnt_opts(&new_sec_opts); 1539 if (data) { 1540 error = parse_security_options(data, &new_sec_opts); 1541 if (error) 1542 return ERR_PTR(error); 1543 } 1544 1545 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); 1546 if (error) 1547 goto error_sec_opts; 1548 1549 /* 1550 * Setup a dummy root and fs_info for test/set super. This is because 1551 * we don't actually fill this stuff out until open_ctree, but we need 1552 * it for searching for existing supers, so this lets us do that and 1553 * then open_ctree will properly initialize everything later. 1554 */ 1555 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); 1556 if (!fs_info) { 1557 error = -ENOMEM; 1558 goto error_sec_opts; 1559 } 1560 1561 fs_info->fs_devices = fs_devices; 1562 1563 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1564 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1565 security_init_mnt_opts(&fs_info->security_opts); 1566 if (!fs_info->super_copy || !fs_info->super_for_commit) { 1567 error = -ENOMEM; 1568 goto error_fs_info; 1569 } 1570 1571 error = btrfs_open_devices(fs_devices, mode, fs_type); 1572 if (error) 1573 goto error_fs_info; 1574 1575 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 1576 error = -EACCES; 1577 goto error_close_devices; 1578 } 1579 1580 bdev = fs_devices->latest_bdev; 1581 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC, 1582 fs_info); 1583 if (IS_ERR(s)) { 1584 error = PTR_ERR(s); 1585 goto error_close_devices; 1586 } 1587 1588 if (s->s_root) { 1589 btrfs_close_devices(fs_devices); 1590 free_fs_info(fs_info); 1591 if ((flags ^ s->s_flags) & MS_RDONLY) 1592 error = -EBUSY; 1593 } else { 1594 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); 1595 btrfs_sb(s)->bdev_holder = fs_type; 1596 error = btrfs_fill_super(s, fs_devices, data, 1597 flags & MS_SILENT ? 1 : 0); 1598 } 1599 if (error) { 1600 deactivate_locked_super(s); 1601 goto error_sec_opts; 1602 } 1603 1604 fs_info = btrfs_sb(s); 1605 error = setup_security_options(fs_info, s, &new_sec_opts); 1606 if (error) { 1607 deactivate_locked_super(s); 1608 goto error_sec_opts; 1609 } 1610 1611 return dget(s->s_root); 1612 1613 error_close_devices: 1614 btrfs_close_devices(fs_devices); 1615 error_fs_info: 1616 free_fs_info(fs_info); 1617 error_sec_opts: 1618 security_free_mnt_opts(&new_sec_opts); 1619 return ERR_PTR(error); 1620 } 1621 1622 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, 1623 int new_pool_size, int old_pool_size) 1624 { 1625 if (new_pool_size == old_pool_size) 1626 return; 1627 1628 fs_info->thread_pool_size = new_pool_size; 1629 1630 btrfs_info(fs_info, "resize thread pool %d -> %d", 1631 old_pool_size, new_pool_size); 1632 1633 btrfs_workqueue_set_max(fs_info->workers, new_pool_size); 1634 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size); 1635 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size); 1636 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size); 1637 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size); 1638 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size); 1639 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers, 1640 new_pool_size); 1641 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size); 1642 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size); 1643 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size); 1644 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size); 1645 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers, 1646 new_pool_size); 1647 } 1648 1649 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info) 1650 { 1651 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1652 } 1653 1654 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info, 1655 unsigned long old_opts, int flags) 1656 { 1657 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1658 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1659 (flags & MS_RDONLY))) { 1660 /* wait for any defraggers to finish */ 1661 wait_event(fs_info->transaction_wait, 1662 (atomic_read(&fs_info->defrag_running) == 0)); 1663 if (flags & MS_RDONLY) 1664 sync_filesystem(fs_info->sb); 1665 } 1666 } 1667 1668 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info, 1669 unsigned long old_opts) 1670 { 1671 /* 1672 * We need cleanup all defragable inodes if the autodefragment is 1673 * close or the fs is R/O. 1674 */ 1675 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1676 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1677 (fs_info->sb->s_flags & MS_RDONLY))) { 1678 btrfs_cleanup_defrag_inodes(fs_info); 1679 } 1680 1681 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1682 } 1683 1684 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1685 { 1686 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1687 struct btrfs_root *root = fs_info->tree_root; 1688 unsigned old_flags = sb->s_flags; 1689 unsigned long old_opts = fs_info->mount_opt; 1690 unsigned long old_compress_type = fs_info->compress_type; 1691 u64 old_max_inline = fs_info->max_inline; 1692 u64 old_alloc_start = fs_info->alloc_start; 1693 int old_thread_pool_size = fs_info->thread_pool_size; 1694 unsigned int old_metadata_ratio = fs_info->metadata_ratio; 1695 int ret; 1696 1697 sync_filesystem(sb); 1698 btrfs_remount_prepare(fs_info); 1699 1700 if (data) { 1701 struct security_mnt_opts new_sec_opts; 1702 1703 security_init_mnt_opts(&new_sec_opts); 1704 ret = parse_security_options(data, &new_sec_opts); 1705 if (ret) 1706 goto restore; 1707 ret = setup_security_options(fs_info, sb, 1708 &new_sec_opts); 1709 if (ret) { 1710 security_free_mnt_opts(&new_sec_opts); 1711 goto restore; 1712 } 1713 } 1714 1715 ret = btrfs_parse_options(root, data, *flags); 1716 if (ret) { 1717 ret = -EINVAL; 1718 goto restore; 1719 } 1720 1721 btrfs_remount_begin(fs_info, old_opts, *flags); 1722 btrfs_resize_thread_pool(fs_info, 1723 fs_info->thread_pool_size, old_thread_pool_size); 1724 1725 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1726 goto out; 1727 1728 if (*flags & MS_RDONLY) { 1729 /* 1730 * this also happens on 'umount -rf' or on shutdown, when 1731 * the filesystem is busy. 1732 */ 1733 cancel_work_sync(&fs_info->async_reclaim_work); 1734 1735 /* wait for the uuid_scan task to finish */ 1736 down(&fs_info->uuid_tree_rescan_sem); 1737 /* avoid complains from lockdep et al. */ 1738 up(&fs_info->uuid_tree_rescan_sem); 1739 1740 sb->s_flags |= MS_RDONLY; 1741 1742 /* 1743 * Setting MS_RDONLY will put the cleaner thread to 1744 * sleep at the next loop if it's already active. 1745 * If it's already asleep, we'll leave unused block 1746 * groups on disk until we're mounted read-write again 1747 * unless we clean them up here. 1748 */ 1749 btrfs_delete_unused_bgs(fs_info); 1750 1751 btrfs_dev_replace_suspend_for_unmount(fs_info); 1752 btrfs_scrub_cancel(fs_info); 1753 btrfs_pause_balance(fs_info); 1754 1755 ret = btrfs_commit_super(root); 1756 if (ret) 1757 goto restore; 1758 } else { 1759 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) { 1760 btrfs_err(fs_info, 1761 "Remounting read-write after error is not allowed"); 1762 ret = -EINVAL; 1763 goto restore; 1764 } 1765 if (fs_info->fs_devices->rw_devices == 0) { 1766 ret = -EACCES; 1767 goto restore; 1768 } 1769 1770 if (fs_info->fs_devices->missing_devices > 1771 fs_info->num_tolerated_disk_barrier_failures && 1772 !(*flags & MS_RDONLY)) { 1773 btrfs_warn(fs_info, 1774 "too many missing devices, writeable remount is not allowed"); 1775 ret = -EACCES; 1776 goto restore; 1777 } 1778 1779 if (btrfs_super_log_root(fs_info->super_copy) != 0) { 1780 ret = -EINVAL; 1781 goto restore; 1782 } 1783 1784 ret = btrfs_cleanup_fs_roots(fs_info); 1785 if (ret) 1786 goto restore; 1787 1788 /* recover relocation */ 1789 mutex_lock(&fs_info->cleaner_mutex); 1790 ret = btrfs_recover_relocation(root); 1791 mutex_unlock(&fs_info->cleaner_mutex); 1792 if (ret) 1793 goto restore; 1794 1795 ret = btrfs_resume_balance_async(fs_info); 1796 if (ret) 1797 goto restore; 1798 1799 ret = btrfs_resume_dev_replace_async(fs_info); 1800 if (ret) { 1801 btrfs_warn(fs_info, "failed to resume dev_replace"); 1802 goto restore; 1803 } 1804 1805 if (!fs_info->uuid_root) { 1806 btrfs_info(fs_info, "creating UUID tree"); 1807 ret = btrfs_create_uuid_tree(fs_info); 1808 if (ret) { 1809 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret); 1810 goto restore; 1811 } 1812 } 1813 sb->s_flags &= ~MS_RDONLY; 1814 } 1815 out: 1816 wake_up_process(fs_info->transaction_kthread); 1817 btrfs_remount_cleanup(fs_info, old_opts); 1818 return 0; 1819 1820 restore: 1821 /* We've hit an error - don't reset MS_RDONLY */ 1822 if (sb->s_flags & MS_RDONLY) 1823 old_flags |= MS_RDONLY; 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 mutex_lock(&fs_info->chunk_mutex); 1829 fs_info->alloc_start = old_alloc_start; 1830 mutex_unlock(&fs_info->chunk_mutex); 1831 btrfs_resize_thread_pool(fs_info, 1832 old_thread_pool_size, fs_info->thread_pool_size); 1833 fs_info->metadata_ratio = old_metadata_ratio; 1834 btrfs_remount_cleanup(fs_info, old_opts); 1835 return ret; 1836 } 1837 1838 /* Used to sort the devices by max_avail(descending sort) */ 1839 static int btrfs_cmp_device_free_bytes(const void *dev_info1, 1840 const void *dev_info2) 1841 { 1842 if (((struct btrfs_device_info *)dev_info1)->max_avail > 1843 ((struct btrfs_device_info *)dev_info2)->max_avail) 1844 return -1; 1845 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 1846 ((struct btrfs_device_info *)dev_info2)->max_avail) 1847 return 1; 1848 else 1849 return 0; 1850 } 1851 1852 /* 1853 * sort the devices by max_avail, in which max free extent size of each device 1854 * is stored.(Descending Sort) 1855 */ 1856 static inline void btrfs_descending_sort_devices( 1857 struct btrfs_device_info *devices, 1858 size_t nr_devices) 1859 { 1860 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1861 btrfs_cmp_device_free_bytes, NULL); 1862 } 1863 1864 /* 1865 * The helper to calc the free space on the devices that can be used to store 1866 * file data. 1867 */ 1868 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) 1869 { 1870 struct btrfs_fs_info *fs_info = root->fs_info; 1871 struct btrfs_device_info *devices_info; 1872 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1873 struct btrfs_device *device; 1874 u64 skip_space; 1875 u64 type; 1876 u64 avail_space; 1877 u64 used_space; 1878 u64 min_stripe_size; 1879 int min_stripes = 1, num_stripes = 1; 1880 int i = 0, nr_devices; 1881 int ret; 1882 1883 /* 1884 * We aren't under the device list lock, so this is racey-ish, but good 1885 * enough for our purposes. 1886 */ 1887 nr_devices = fs_info->fs_devices->open_devices; 1888 if (!nr_devices) { 1889 smp_mb(); 1890 nr_devices = fs_info->fs_devices->open_devices; 1891 ASSERT(nr_devices); 1892 if (!nr_devices) { 1893 *free_bytes = 0; 1894 return 0; 1895 } 1896 } 1897 1898 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info), 1899 GFP_NOFS); 1900 if (!devices_info) 1901 return -ENOMEM; 1902 1903 /* calc min stripe number for data space alloction */ 1904 type = btrfs_get_alloc_profile(root, 1); 1905 if (type & BTRFS_BLOCK_GROUP_RAID0) { 1906 min_stripes = 2; 1907 num_stripes = nr_devices; 1908 } else if (type & BTRFS_BLOCK_GROUP_RAID1) { 1909 min_stripes = 2; 1910 num_stripes = 2; 1911 } else if (type & BTRFS_BLOCK_GROUP_RAID10) { 1912 min_stripes = 4; 1913 num_stripes = 4; 1914 } 1915 1916 if (type & BTRFS_BLOCK_GROUP_DUP) 1917 min_stripe_size = 2 * BTRFS_STRIPE_LEN; 1918 else 1919 min_stripe_size = BTRFS_STRIPE_LEN; 1920 1921 if (fs_info->alloc_start) 1922 mutex_lock(&fs_devices->device_list_mutex); 1923 rcu_read_lock(); 1924 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { 1925 if (!device->in_fs_metadata || !device->bdev || 1926 device->is_tgtdev_for_dev_replace) 1927 continue; 1928 1929 if (i >= nr_devices) 1930 break; 1931 1932 avail_space = device->total_bytes - device->bytes_used; 1933 1934 /* align with stripe_len */ 1935 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN); 1936 avail_space *= BTRFS_STRIPE_LEN; 1937 1938 /* 1939 * In order to avoid overwritting the superblock on the drive, 1940 * btrfs starts at an offset of at least 1MB when doing chunk 1941 * allocation. 1942 */ 1943 skip_space = SZ_1M; 1944 1945 /* user can set the offset in fs_info->alloc_start. */ 1946 if (fs_info->alloc_start && 1947 fs_info->alloc_start + BTRFS_STRIPE_LEN <= 1948 device->total_bytes) { 1949 rcu_read_unlock(); 1950 skip_space = max(fs_info->alloc_start, skip_space); 1951 1952 /* 1953 * btrfs can not use the free space in 1954 * [0, skip_space - 1], we must subtract it from the 1955 * total. In order to implement it, we account the used 1956 * space in this range first. 1957 */ 1958 ret = btrfs_account_dev_extents_size(device, 0, 1959 skip_space - 1, 1960 &used_space); 1961 if (ret) { 1962 kfree(devices_info); 1963 mutex_unlock(&fs_devices->device_list_mutex); 1964 return ret; 1965 } 1966 1967 rcu_read_lock(); 1968 1969 /* calc the free space in [0, skip_space - 1] */ 1970 skip_space -= used_space; 1971 } 1972 1973 /* 1974 * we can use the free space in [0, skip_space - 1], subtract 1975 * it from the total. 1976 */ 1977 if (avail_space && avail_space >= skip_space) 1978 avail_space -= skip_space; 1979 else 1980 avail_space = 0; 1981 1982 if (avail_space < min_stripe_size) 1983 continue; 1984 1985 devices_info[i].dev = device; 1986 devices_info[i].max_avail = avail_space; 1987 1988 i++; 1989 } 1990 rcu_read_unlock(); 1991 if (fs_info->alloc_start) 1992 mutex_unlock(&fs_devices->device_list_mutex); 1993 1994 nr_devices = i; 1995 1996 btrfs_descending_sort_devices(devices_info, nr_devices); 1997 1998 i = nr_devices - 1; 1999 avail_space = 0; 2000 while (nr_devices >= min_stripes) { 2001 if (num_stripes > nr_devices) 2002 num_stripes = nr_devices; 2003 2004 if (devices_info[i].max_avail >= min_stripe_size) { 2005 int j; 2006 u64 alloc_size; 2007 2008 avail_space += devices_info[i].max_avail * num_stripes; 2009 alloc_size = devices_info[i].max_avail; 2010 for (j = i + 1 - num_stripes; j <= i; j++) 2011 devices_info[j].max_avail -= alloc_size; 2012 } 2013 i--; 2014 nr_devices--; 2015 } 2016 2017 kfree(devices_info); 2018 *free_bytes = avail_space; 2019 return 0; 2020 } 2021 2022 /* 2023 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles. 2024 * 2025 * If there's a redundant raid level at DATA block groups, use the respective 2026 * multiplier to scale the sizes. 2027 * 2028 * Unused device space usage is based on simulating the chunk allocator 2029 * algorithm that respects the device sizes, order of allocations and the 2030 * 'alloc_start' value, this is a close approximation of the actual use but 2031 * there are other factors that may change the result (like a new metadata 2032 * chunk). 2033 * 2034 * If metadata is exhausted, f_bavail will be 0. 2035 * 2036 * FIXME: not accurate for mixed block groups, total and free/used are ok, 2037 * available appears slightly larger. 2038 */ 2039 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 2040 { 2041 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); 2042 struct btrfs_super_block *disk_super = fs_info->super_copy; 2043 struct list_head *head = &fs_info->space_info; 2044 struct btrfs_space_info *found; 2045 u64 total_used = 0; 2046 u64 total_free_data = 0; 2047 u64 total_free_meta = 0; 2048 int bits = dentry->d_sb->s_blocksize_bits; 2049 __be32 *fsid = (__be32 *)fs_info->fsid; 2050 unsigned factor = 1; 2051 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 2052 int ret; 2053 u64 thresh = 0; 2054 2055 /* 2056 * holding chunk_muext to avoid allocating new chunks, holding 2057 * device_list_mutex to avoid the device being removed 2058 */ 2059 rcu_read_lock(); 2060 list_for_each_entry_rcu(found, head, list) { 2061 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 2062 int i; 2063 2064 total_free_data += found->disk_total - found->disk_used; 2065 total_free_data -= 2066 btrfs_account_ro_block_groups_free_space(found); 2067 2068 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { 2069 if (!list_empty(&found->block_groups[i])) { 2070 switch (i) { 2071 case BTRFS_RAID_DUP: 2072 case BTRFS_RAID_RAID1: 2073 case BTRFS_RAID_RAID10: 2074 factor = 2; 2075 } 2076 } 2077 } 2078 } 2079 if (found->flags & BTRFS_BLOCK_GROUP_METADATA) 2080 total_free_meta += found->disk_total - found->disk_used; 2081 2082 total_used += found->disk_used; 2083 } 2084 2085 rcu_read_unlock(); 2086 2087 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor); 2088 buf->f_blocks >>= bits; 2089 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits); 2090 2091 /* Account global block reserve as used, it's in logical size already */ 2092 spin_lock(&block_rsv->lock); 2093 buf->f_bfree -= block_rsv->size >> bits; 2094 spin_unlock(&block_rsv->lock); 2095 2096 buf->f_bavail = div_u64(total_free_data, factor); 2097 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data); 2098 if (ret) 2099 return ret; 2100 buf->f_bavail += div_u64(total_free_data, factor); 2101 buf->f_bavail = buf->f_bavail >> bits; 2102 2103 /* 2104 * We calculate the remaining metadata space minus global reserve. If 2105 * this is (supposedly) smaller than zero, there's no space. But this 2106 * does not hold in practice, the exhausted state happens where's still 2107 * some positive delta. So we apply some guesswork and compare the 2108 * delta to a 4M threshold. (Practically observed delta was ~2M.) 2109 * 2110 * We probably cannot calculate the exact threshold value because this 2111 * depends on the internal reservations requested by various 2112 * operations, so some operations that consume a few metadata will 2113 * succeed even if the Avail is zero. But this is better than the other 2114 * way around. 2115 */ 2116 thresh = 4 * 1024 * 1024; 2117 2118 if (total_free_meta - thresh < block_rsv->size) 2119 buf->f_bavail = 0; 2120 2121 buf->f_type = BTRFS_SUPER_MAGIC; 2122 buf->f_bsize = dentry->d_sb->s_blocksize; 2123 buf->f_namelen = BTRFS_NAME_LEN; 2124 2125 /* We treat it as constant endianness (it doesn't matter _which_) 2126 because we want the fsid to come out the same whether mounted 2127 on a big-endian or little-endian host */ 2128 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 2129 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 2130 /* Mask in the root object ID too, to disambiguate subvols */ 2131 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32; 2132 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid; 2133 2134 return 0; 2135 } 2136 2137 static void btrfs_kill_super(struct super_block *sb) 2138 { 2139 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2140 kill_anon_super(sb); 2141 free_fs_info(fs_info); 2142 } 2143 2144 static struct file_system_type btrfs_fs_type = { 2145 .owner = THIS_MODULE, 2146 .name = "btrfs", 2147 .mount = btrfs_mount, 2148 .kill_sb = btrfs_kill_super, 2149 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, 2150 }; 2151 MODULE_ALIAS_FS("btrfs"); 2152 2153 static int btrfs_control_open(struct inode *inode, struct file *file) 2154 { 2155 /* 2156 * The control file's private_data is used to hold the 2157 * transaction when it is started and is used to keep 2158 * track of whether a transaction is already in progress. 2159 */ 2160 file->private_data = NULL; 2161 return 0; 2162 } 2163 2164 /* 2165 * used by btrfsctl to scan devices when no FS is mounted 2166 */ 2167 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 2168 unsigned long arg) 2169 { 2170 struct btrfs_ioctl_vol_args *vol; 2171 struct btrfs_fs_devices *fs_devices; 2172 int ret = -ENOTTY; 2173 2174 if (!capable(CAP_SYS_ADMIN)) 2175 return -EPERM; 2176 2177 vol = memdup_user((void __user *)arg, sizeof(*vol)); 2178 if (IS_ERR(vol)) 2179 return PTR_ERR(vol); 2180 2181 switch (cmd) { 2182 case BTRFS_IOC_SCAN_DEV: 2183 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 2184 &btrfs_fs_type, &fs_devices); 2185 break; 2186 case BTRFS_IOC_DEVICES_READY: 2187 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 2188 &btrfs_fs_type, &fs_devices); 2189 if (ret) 2190 break; 2191 ret = !(fs_devices->num_devices == fs_devices->total_devices); 2192 break; 2193 case BTRFS_IOC_GET_SUPPORTED_FEATURES: 2194 ret = btrfs_ioctl_get_supported_features((void __user*)arg); 2195 break; 2196 } 2197 2198 kfree(vol); 2199 return ret; 2200 } 2201 2202 static int btrfs_freeze(struct super_block *sb) 2203 { 2204 struct btrfs_trans_handle *trans; 2205 struct btrfs_root *root = btrfs_sb(sb)->tree_root; 2206 2207 trans = btrfs_attach_transaction_barrier(root); 2208 if (IS_ERR(trans)) { 2209 /* no transaction, don't bother */ 2210 if (PTR_ERR(trans) == -ENOENT) 2211 return 0; 2212 return PTR_ERR(trans); 2213 } 2214 return btrfs_commit_transaction(trans, root); 2215 } 2216 2217 static int btrfs_show_devname(struct seq_file *m, struct dentry *root) 2218 { 2219 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); 2220 struct btrfs_fs_devices *cur_devices; 2221 struct btrfs_device *dev, *first_dev = NULL; 2222 struct list_head *head; 2223 struct rcu_string *name; 2224 2225 mutex_lock(&fs_info->fs_devices->device_list_mutex); 2226 cur_devices = fs_info->fs_devices; 2227 while (cur_devices) { 2228 head = &cur_devices->devices; 2229 list_for_each_entry(dev, head, dev_list) { 2230 if (dev->missing) 2231 continue; 2232 if (!dev->name) 2233 continue; 2234 if (!first_dev || dev->devid < first_dev->devid) 2235 first_dev = dev; 2236 } 2237 cur_devices = cur_devices->seed; 2238 } 2239 2240 if (first_dev) { 2241 rcu_read_lock(); 2242 name = rcu_dereference(first_dev->name); 2243 seq_escape(m, name->str, " \t\n\\"); 2244 rcu_read_unlock(); 2245 } else { 2246 WARN_ON(1); 2247 } 2248 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2249 return 0; 2250 } 2251 2252 static const struct super_operations btrfs_super_ops = { 2253 .drop_inode = btrfs_drop_inode, 2254 .evict_inode = btrfs_evict_inode, 2255 .put_super = btrfs_put_super, 2256 .sync_fs = btrfs_sync_fs, 2257 .show_options = btrfs_show_options, 2258 .show_devname = btrfs_show_devname, 2259 .write_inode = btrfs_write_inode, 2260 .alloc_inode = btrfs_alloc_inode, 2261 .destroy_inode = btrfs_destroy_inode, 2262 .statfs = btrfs_statfs, 2263 .remount_fs = btrfs_remount, 2264 .freeze_fs = btrfs_freeze, 2265 }; 2266 2267 static const struct file_operations btrfs_ctl_fops = { 2268 .open = btrfs_control_open, 2269 .unlocked_ioctl = btrfs_control_ioctl, 2270 .compat_ioctl = btrfs_control_ioctl, 2271 .owner = THIS_MODULE, 2272 .llseek = noop_llseek, 2273 }; 2274 2275 static struct miscdevice btrfs_misc = { 2276 .minor = BTRFS_MINOR, 2277 .name = "btrfs-control", 2278 .fops = &btrfs_ctl_fops 2279 }; 2280 2281 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 2282 MODULE_ALIAS("devname:btrfs-control"); 2283 2284 static int btrfs_interface_init(void) 2285 { 2286 return misc_register(&btrfs_misc); 2287 } 2288 2289 static void btrfs_interface_exit(void) 2290 { 2291 misc_deregister(&btrfs_misc); 2292 } 2293 2294 static void btrfs_print_mod_info(void) 2295 { 2296 printk(KERN_INFO "Btrfs loaded" 2297 #ifdef CONFIG_BTRFS_DEBUG 2298 ", debug=on" 2299 #endif 2300 #ifdef CONFIG_BTRFS_ASSERT 2301 ", assert=on" 2302 #endif 2303 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 2304 ", integrity-checker=on" 2305 #endif 2306 "\n"); 2307 } 2308 2309 static int btrfs_run_sanity_tests(void) 2310 { 2311 int ret; 2312 2313 ret = btrfs_init_test_fs(); 2314 if (ret) 2315 return ret; 2316 2317 ret = btrfs_test_free_space_cache(); 2318 if (ret) 2319 goto out; 2320 ret = btrfs_test_extent_buffer_operations(); 2321 if (ret) 2322 goto out; 2323 ret = btrfs_test_extent_io(); 2324 if (ret) 2325 goto out; 2326 ret = btrfs_test_inodes(); 2327 if (ret) 2328 goto out; 2329 ret = btrfs_test_qgroups(); 2330 if (ret) 2331 goto out; 2332 ret = btrfs_test_free_space_tree(); 2333 out: 2334 btrfs_destroy_test_fs(); 2335 return ret; 2336 } 2337 2338 static int __init init_btrfs_fs(void) 2339 { 2340 int err; 2341 2342 err = btrfs_hash_init(); 2343 if (err) 2344 return err; 2345 2346 btrfs_props_init(); 2347 2348 err = btrfs_init_sysfs(); 2349 if (err) 2350 goto free_hash; 2351 2352 btrfs_init_compress(); 2353 2354 err = btrfs_init_cachep(); 2355 if (err) 2356 goto free_compress; 2357 2358 err = extent_io_init(); 2359 if (err) 2360 goto free_cachep; 2361 2362 err = extent_map_init(); 2363 if (err) 2364 goto free_extent_io; 2365 2366 err = ordered_data_init(); 2367 if (err) 2368 goto free_extent_map; 2369 2370 err = btrfs_delayed_inode_init(); 2371 if (err) 2372 goto free_ordered_data; 2373 2374 err = btrfs_auto_defrag_init(); 2375 if (err) 2376 goto free_delayed_inode; 2377 2378 err = btrfs_delayed_ref_init(); 2379 if (err) 2380 goto free_auto_defrag; 2381 2382 err = btrfs_prelim_ref_init(); 2383 if (err) 2384 goto free_delayed_ref; 2385 2386 err = btrfs_end_io_wq_init(); 2387 if (err) 2388 goto free_prelim_ref; 2389 2390 err = btrfs_interface_init(); 2391 if (err) 2392 goto free_end_io_wq; 2393 2394 btrfs_init_lockdep(); 2395 2396 btrfs_print_mod_info(); 2397 2398 err = btrfs_run_sanity_tests(); 2399 if (err) 2400 goto unregister_ioctl; 2401 2402 err = register_filesystem(&btrfs_fs_type); 2403 if (err) 2404 goto unregister_ioctl; 2405 2406 return 0; 2407 2408 unregister_ioctl: 2409 btrfs_interface_exit(); 2410 free_end_io_wq: 2411 btrfs_end_io_wq_exit(); 2412 free_prelim_ref: 2413 btrfs_prelim_ref_exit(); 2414 free_delayed_ref: 2415 btrfs_delayed_ref_exit(); 2416 free_auto_defrag: 2417 btrfs_auto_defrag_exit(); 2418 free_delayed_inode: 2419 btrfs_delayed_inode_exit(); 2420 free_ordered_data: 2421 ordered_data_exit(); 2422 free_extent_map: 2423 extent_map_exit(); 2424 free_extent_io: 2425 extent_io_exit(); 2426 free_cachep: 2427 btrfs_destroy_cachep(); 2428 free_compress: 2429 btrfs_exit_compress(); 2430 btrfs_exit_sysfs(); 2431 free_hash: 2432 btrfs_hash_exit(); 2433 return err; 2434 } 2435 2436 static void __exit exit_btrfs_fs(void) 2437 { 2438 btrfs_destroy_cachep(); 2439 btrfs_delayed_ref_exit(); 2440 btrfs_auto_defrag_exit(); 2441 btrfs_delayed_inode_exit(); 2442 btrfs_prelim_ref_exit(); 2443 ordered_data_exit(); 2444 extent_map_exit(); 2445 extent_io_exit(); 2446 btrfs_interface_exit(); 2447 btrfs_end_io_wq_exit(); 2448 unregister_filesystem(&btrfs_fs_type); 2449 btrfs_exit_sysfs(); 2450 btrfs_cleanup_fs_uuids(); 2451 btrfs_exit_compress(); 2452 btrfs_hash_exit(); 2453 } 2454 2455 late_initcall(init_btrfs_fs); 2456 module_exit(exit_btrfs_fs) 2457 2458 MODULE_LICENSE("GPL"); 2459