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 /* btrfs handle error by forcing the filesystem readonly */ 101 static void btrfs_handle_error(struct btrfs_fs_info *fs_info) 102 { 103 struct super_block *sb = fs_info->sb; 104 105 if (sb->s_flags & MS_RDONLY) 106 return; 107 108 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { 109 sb->s_flags |= MS_RDONLY; 110 btrfs_info(fs_info, "forced readonly"); 111 /* 112 * Note that a running device replace operation is not 113 * canceled here although there is no way to update 114 * the progress. It would add the risk of a deadlock, 115 * therefore the canceling is omitted. The only penalty 116 * is that some I/O remains active until the procedure 117 * completes. The next time when the filesystem is 118 * mounted writeable again, the device replace 119 * operation continues. 120 */ 121 } 122 } 123 124 /* 125 * __btrfs_handle_fs_error decodes expected errors from the caller and 126 * invokes the approciate error response. 127 */ 128 __cold 129 void __btrfs_handle_fs_error(struct btrfs_fs_info *fs_info, const char *function, 130 unsigned int line, int errno, const char *fmt, ...) 131 { 132 struct super_block *sb = fs_info->sb; 133 #ifdef CONFIG_PRINTK 134 const char *errstr; 135 #endif 136 137 /* 138 * Special case: if the error is EROFS, and we're already 139 * under MS_RDONLY, then it is safe here. 140 */ 141 if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) 142 return; 143 144 #ifdef CONFIG_PRINTK 145 errstr = btrfs_decode_error(errno); 146 if (fmt) { 147 struct va_format vaf; 148 va_list args; 149 150 va_start(args, fmt); 151 vaf.fmt = fmt; 152 vaf.va = &args; 153 154 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n", 155 sb->s_id, function, line, errno, errstr, &vaf); 156 va_end(args); 157 } else { 158 pr_crit("BTRFS: error (device %s) in %s:%d: errno=%d %s\n", 159 sb->s_id, function, line, errno, errstr); 160 } 161 #endif 162 163 /* 164 * Today we only save the error info to memory. Long term we'll 165 * also send it down to the disk 166 */ 167 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state); 168 169 /* Don't go through full error handling during mount */ 170 if (sb->s_flags & MS_BORN) 171 btrfs_handle_error(fs_info); 172 } 173 174 #ifdef CONFIG_PRINTK 175 static const char * const logtypes[] = { 176 "emergency", 177 "alert", 178 "critical", 179 "error", 180 "warning", 181 "notice", 182 "info", 183 "debug", 184 }; 185 186 187 /* 188 * Use one ratelimit state per log level so that a flood of less important 189 * messages doesn't cause more important ones to be dropped. 190 */ 191 static struct ratelimit_state printk_limits[] = { 192 RATELIMIT_STATE_INIT(printk_limits[0], DEFAULT_RATELIMIT_INTERVAL, 100), 193 RATELIMIT_STATE_INIT(printk_limits[1], DEFAULT_RATELIMIT_INTERVAL, 100), 194 RATELIMIT_STATE_INIT(printk_limits[2], DEFAULT_RATELIMIT_INTERVAL, 100), 195 RATELIMIT_STATE_INIT(printk_limits[3], DEFAULT_RATELIMIT_INTERVAL, 100), 196 RATELIMIT_STATE_INIT(printk_limits[4], DEFAULT_RATELIMIT_INTERVAL, 100), 197 RATELIMIT_STATE_INIT(printk_limits[5], DEFAULT_RATELIMIT_INTERVAL, 100), 198 RATELIMIT_STATE_INIT(printk_limits[6], DEFAULT_RATELIMIT_INTERVAL, 100), 199 RATELIMIT_STATE_INIT(printk_limits[7], DEFAULT_RATELIMIT_INTERVAL, 100), 200 }; 201 202 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...) 203 { 204 struct super_block *sb = fs_info->sb; 205 char lvl[PRINTK_MAX_SINGLE_HEADER_LEN + 1] = "\0"; 206 struct va_format vaf; 207 va_list args; 208 int kern_level; 209 const char *type = logtypes[4]; 210 struct ratelimit_state *ratelimit = &printk_limits[4]; 211 212 va_start(args, fmt); 213 214 while ((kern_level = printk_get_level(fmt)) != 0) { 215 size_t size = printk_skip_level(fmt) - fmt; 216 217 if (kern_level >= '0' && kern_level <= '7') { 218 memcpy(lvl, fmt, size); 219 lvl[size] = '\0'; 220 type = logtypes[kern_level - '0']; 221 ratelimit = &printk_limits[kern_level - '0']; 222 } 223 fmt += size; 224 } 225 226 vaf.fmt = fmt; 227 vaf.va = &args; 228 229 if (__ratelimit(ratelimit)) 230 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf); 231 232 va_end(args); 233 } 234 #endif 235 236 /* 237 * We only mark the transaction aborted and then set the file system read-only. 238 * This will prevent new transactions from starting or trying to join this 239 * one. 240 * 241 * This means that error recovery at the call site is limited to freeing 242 * any local memory allocations and passing the error code up without 243 * further cleanup. The transaction should complete as it normally would 244 * in the call path but will return -EIO. 245 * 246 * We'll complete the cleanup in btrfs_end_transaction and 247 * btrfs_commit_transaction. 248 */ 249 __cold 250 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 251 const char *function, 252 unsigned int line, int errno) 253 { 254 struct btrfs_fs_info *fs_info = trans->fs_info; 255 256 trans->aborted = errno; 257 /* Nothing used. The other threads that have joined this 258 * transaction may be able to continue. */ 259 if (!trans->dirty && list_empty(&trans->new_bgs)) { 260 const char *errstr; 261 262 errstr = btrfs_decode_error(errno); 263 btrfs_warn(fs_info, 264 "%s:%d: Aborting unused transaction(%s).", 265 function, line, errstr); 266 return; 267 } 268 WRITE_ONCE(trans->transaction->aborted, errno); 269 /* Wake up anybody who may be waiting on this transaction */ 270 wake_up(&fs_info->transaction_wait); 271 wake_up(&fs_info->transaction_blocked_wait); 272 __btrfs_handle_fs_error(fs_info, function, line, errno, NULL); 273 } 274 /* 275 * __btrfs_panic decodes unexpected, fatal errors from the caller, 276 * issues an alert, and either panics or BUGs, depending on mount options. 277 */ 278 __cold 279 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, 280 unsigned int line, int errno, const char *fmt, ...) 281 { 282 char *s_id = "<unknown>"; 283 const char *errstr; 284 struct va_format vaf = { .fmt = fmt }; 285 va_list args; 286 287 if (fs_info) 288 s_id = fs_info->sb->s_id; 289 290 va_start(args, fmt); 291 vaf.va = &args; 292 293 errstr = btrfs_decode_error(errno); 294 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR)) 295 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n", 296 s_id, function, line, &vaf, errno, errstr); 297 298 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)", 299 function, line, &vaf, errno, errstr); 300 va_end(args); 301 /* Caller calls BUG() */ 302 } 303 304 static void btrfs_put_super(struct super_block *sb) 305 { 306 close_ctree(btrfs_sb(sb)); 307 } 308 309 enum { 310 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, 311 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, 312 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, 313 Opt_compress_type, Opt_compress_force, Opt_compress_force_type, 314 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, 315 Opt_space_cache, Opt_space_cache_version, Opt_clear_cache, 316 Opt_user_subvol_rm_allowed, Opt_enospc_debug, Opt_subvolrootid, 317 Opt_defrag, Opt_inode_cache, Opt_no_space_cache, Opt_recovery, 318 Opt_skip_balance, Opt_check_integrity, 319 Opt_check_integrity_including_extent_data, 320 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree, 321 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard, 322 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow, 323 Opt_datasum, Opt_treelog, Opt_noinode_cache, Opt_usebackuproot, 324 Opt_nologreplay, Opt_norecovery, 325 #ifdef CONFIG_BTRFS_DEBUG 326 Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all, 327 #endif 328 Opt_err, 329 }; 330 331 static const match_table_t tokens = { 332 {Opt_degraded, "degraded"}, 333 {Opt_subvol, "subvol=%s"}, 334 {Opt_subvolid, "subvolid=%s"}, 335 {Opt_device, "device=%s"}, 336 {Opt_nodatasum, "nodatasum"}, 337 {Opt_datasum, "datasum"}, 338 {Opt_nodatacow, "nodatacow"}, 339 {Opt_datacow, "datacow"}, 340 {Opt_nobarrier, "nobarrier"}, 341 {Opt_barrier, "barrier"}, 342 {Opt_max_inline, "max_inline=%s"}, 343 {Opt_alloc_start, "alloc_start=%s"}, 344 {Opt_thread_pool, "thread_pool=%d"}, 345 {Opt_compress, "compress"}, 346 {Opt_compress_type, "compress=%s"}, 347 {Opt_compress_force, "compress-force"}, 348 {Opt_compress_force_type, "compress-force=%s"}, 349 {Opt_ssd, "ssd"}, 350 {Opt_ssd_spread, "ssd_spread"}, 351 {Opt_nossd, "nossd"}, 352 {Opt_acl, "acl"}, 353 {Opt_noacl, "noacl"}, 354 {Opt_notreelog, "notreelog"}, 355 {Opt_treelog, "treelog"}, 356 {Opt_nologreplay, "nologreplay"}, 357 {Opt_norecovery, "norecovery"}, 358 {Opt_flushoncommit, "flushoncommit"}, 359 {Opt_noflushoncommit, "noflushoncommit"}, 360 {Opt_ratio, "metadata_ratio=%d"}, 361 {Opt_discard, "discard"}, 362 {Opt_nodiscard, "nodiscard"}, 363 {Opt_space_cache, "space_cache"}, 364 {Opt_space_cache_version, "space_cache=%s"}, 365 {Opt_clear_cache, "clear_cache"}, 366 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, 367 {Opt_enospc_debug, "enospc_debug"}, 368 {Opt_noenospc_debug, "noenospc_debug"}, 369 {Opt_subvolrootid, "subvolrootid=%d"}, 370 {Opt_defrag, "autodefrag"}, 371 {Opt_nodefrag, "noautodefrag"}, 372 {Opt_inode_cache, "inode_cache"}, 373 {Opt_noinode_cache, "noinode_cache"}, 374 {Opt_no_space_cache, "nospace_cache"}, 375 {Opt_recovery, "recovery"}, /* deprecated */ 376 {Opt_usebackuproot, "usebackuproot"}, 377 {Opt_skip_balance, "skip_balance"}, 378 {Opt_check_integrity, "check_int"}, 379 {Opt_check_integrity_including_extent_data, "check_int_data"}, 380 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"}, 381 {Opt_rescan_uuid_tree, "rescan_uuid_tree"}, 382 {Opt_fatal_errors, "fatal_errors=%s"}, 383 {Opt_commit_interval, "commit=%d"}, 384 #ifdef CONFIG_BTRFS_DEBUG 385 {Opt_fragment_data, "fragment=data"}, 386 {Opt_fragment_metadata, "fragment=metadata"}, 387 {Opt_fragment_all, "fragment=all"}, 388 #endif 389 {Opt_err, NULL}, 390 }; 391 392 /* 393 * Regular mount options parser. Everything that is needed only when 394 * reading in a new superblock is parsed here. 395 * XXX JDM: This needs to be cleaned up for remount. 396 */ 397 int btrfs_parse_options(struct btrfs_fs_info *info, char *options, 398 unsigned long new_flags) 399 { 400 substring_t args[MAX_OPT_ARGS]; 401 char *p, *num, *orig = NULL; 402 u64 cache_gen; 403 int intarg; 404 int ret = 0; 405 char *compress_type; 406 bool compress_force = false; 407 enum btrfs_compression_type saved_compress_type; 408 bool saved_compress_force; 409 int no_compress = 0; 410 411 cache_gen = btrfs_super_cache_generation(info->super_copy); 412 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE)) 413 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE); 414 else if (cache_gen) 415 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 416 417 /* 418 * Even the options are empty, we still need to do extra check 419 * against new flags 420 */ 421 if (!options) 422 goto check; 423 424 /* 425 * strsep changes the string, duplicate it because parse_options 426 * gets called twice 427 */ 428 options = kstrdup(options, GFP_NOFS); 429 if (!options) 430 return -ENOMEM; 431 432 orig = options; 433 434 while ((p = strsep(&options, ",")) != NULL) { 435 int token; 436 if (!*p) 437 continue; 438 439 token = match_token(p, tokens, args); 440 switch (token) { 441 case Opt_degraded: 442 btrfs_info(info, "allowing degraded mounts"); 443 btrfs_set_opt(info->mount_opt, DEGRADED); 444 break; 445 case Opt_subvol: 446 case Opt_subvolid: 447 case Opt_subvolrootid: 448 case Opt_device: 449 /* 450 * These are parsed by btrfs_parse_early_options 451 * and can be happily ignored here. 452 */ 453 break; 454 case Opt_nodatasum: 455 btrfs_set_and_info(info, NODATASUM, 456 "setting nodatasum"); 457 break; 458 case Opt_datasum: 459 if (btrfs_test_opt(info, NODATASUM)) { 460 if (btrfs_test_opt(info, NODATACOW)) 461 btrfs_info(info, 462 "setting datasum, datacow enabled"); 463 else 464 btrfs_info(info, "setting datasum"); 465 } 466 btrfs_clear_opt(info->mount_opt, NODATACOW); 467 btrfs_clear_opt(info->mount_opt, NODATASUM); 468 break; 469 case Opt_nodatacow: 470 if (!btrfs_test_opt(info, NODATACOW)) { 471 if (!btrfs_test_opt(info, COMPRESS) || 472 !btrfs_test_opt(info, FORCE_COMPRESS)) { 473 btrfs_info(info, 474 "setting nodatacow, compression disabled"); 475 } else { 476 btrfs_info(info, "setting nodatacow"); 477 } 478 } 479 btrfs_clear_opt(info->mount_opt, COMPRESS); 480 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 481 btrfs_set_opt(info->mount_opt, NODATACOW); 482 btrfs_set_opt(info->mount_opt, NODATASUM); 483 break; 484 case Opt_datacow: 485 btrfs_clear_and_info(info, NODATACOW, 486 "setting datacow"); 487 break; 488 case Opt_compress_force: 489 case Opt_compress_force_type: 490 compress_force = true; 491 /* Fallthrough */ 492 case Opt_compress: 493 case Opt_compress_type: 494 saved_compress_type = btrfs_test_opt(info, 495 COMPRESS) ? 496 info->compress_type : BTRFS_COMPRESS_NONE; 497 saved_compress_force = 498 btrfs_test_opt(info, FORCE_COMPRESS); 499 if (token == Opt_compress || 500 token == Opt_compress_force || 501 strcmp(args[0].from, "zlib") == 0) { 502 compress_type = "zlib"; 503 info->compress_type = BTRFS_COMPRESS_ZLIB; 504 btrfs_set_opt(info->mount_opt, COMPRESS); 505 btrfs_clear_opt(info->mount_opt, NODATACOW); 506 btrfs_clear_opt(info->mount_opt, NODATASUM); 507 no_compress = 0; 508 } else if (strcmp(args[0].from, "lzo") == 0) { 509 compress_type = "lzo"; 510 info->compress_type = BTRFS_COMPRESS_LZO; 511 btrfs_set_opt(info->mount_opt, COMPRESS); 512 btrfs_clear_opt(info->mount_opt, NODATACOW); 513 btrfs_clear_opt(info->mount_opt, NODATASUM); 514 btrfs_set_fs_incompat(info, COMPRESS_LZO); 515 no_compress = 0; 516 } else if (strncmp(args[0].from, "no", 2) == 0) { 517 compress_type = "no"; 518 btrfs_clear_opt(info->mount_opt, COMPRESS); 519 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 520 compress_force = false; 521 no_compress++; 522 } else { 523 ret = -EINVAL; 524 goto out; 525 } 526 527 if (compress_force) { 528 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); 529 } else { 530 /* 531 * If we remount from compress-force=xxx to 532 * compress=xxx, we need clear FORCE_COMPRESS 533 * flag, otherwise, there is no way for users 534 * to disable forcible compression separately. 535 */ 536 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 537 } 538 if ((btrfs_test_opt(info, COMPRESS) && 539 (info->compress_type != saved_compress_type || 540 compress_force != saved_compress_force)) || 541 (!btrfs_test_opt(info, COMPRESS) && 542 no_compress == 1)) { 543 btrfs_info(info, "%s %s compression", 544 (compress_force) ? "force" : "use", 545 compress_type); 546 } 547 compress_force = false; 548 break; 549 case Opt_ssd: 550 btrfs_set_and_info(info, SSD, 551 "use ssd allocation scheme"); 552 btrfs_clear_opt(info->mount_opt, NOSSD); 553 break; 554 case Opt_ssd_spread: 555 btrfs_set_and_info(info, SSD_SPREAD, 556 "use spread ssd allocation scheme"); 557 btrfs_set_opt(info->mount_opt, SSD); 558 btrfs_clear_opt(info->mount_opt, NOSSD); 559 break; 560 case Opt_nossd: 561 btrfs_set_and_info(info, NOSSD, 562 "not using ssd allocation scheme"); 563 btrfs_clear_opt(info->mount_opt, SSD); 564 btrfs_clear_opt(info->mount_opt, SSD_SPREAD); 565 break; 566 case Opt_barrier: 567 btrfs_clear_and_info(info, NOBARRIER, 568 "turning on barriers"); 569 break; 570 case Opt_nobarrier: 571 btrfs_set_and_info(info, NOBARRIER, 572 "turning off barriers"); 573 break; 574 case Opt_thread_pool: 575 ret = match_int(&args[0], &intarg); 576 if (ret) { 577 goto out; 578 } else if (intarg > 0) { 579 info->thread_pool_size = intarg; 580 } else { 581 ret = -EINVAL; 582 goto out; 583 } 584 break; 585 case Opt_max_inline: 586 num = match_strdup(&args[0]); 587 if (num) { 588 info->max_inline = memparse(num, NULL); 589 kfree(num); 590 591 if (info->max_inline) { 592 info->max_inline = min_t(u64, 593 info->max_inline, 594 info->sectorsize); 595 } 596 btrfs_info(info, "max_inline at %llu", 597 info->max_inline); 598 } else { 599 ret = -ENOMEM; 600 goto out; 601 } 602 break; 603 case Opt_alloc_start: 604 num = match_strdup(&args[0]); 605 if (num) { 606 mutex_lock(&info->chunk_mutex); 607 info->alloc_start = memparse(num, NULL); 608 mutex_unlock(&info->chunk_mutex); 609 kfree(num); 610 btrfs_info(info, "allocations start at %llu", 611 info->alloc_start); 612 } else { 613 ret = -ENOMEM; 614 goto out; 615 } 616 break; 617 case Opt_acl: 618 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 619 info->sb->s_flags |= MS_POSIXACL; 620 break; 621 #else 622 btrfs_err(info, "support for ACL not compiled in!"); 623 ret = -EINVAL; 624 goto out; 625 #endif 626 case Opt_noacl: 627 info->sb->s_flags &= ~MS_POSIXACL; 628 break; 629 case Opt_notreelog: 630 btrfs_set_and_info(info, NOTREELOG, 631 "disabling tree log"); 632 break; 633 case Opt_treelog: 634 btrfs_clear_and_info(info, NOTREELOG, 635 "enabling tree log"); 636 break; 637 case Opt_norecovery: 638 case Opt_nologreplay: 639 btrfs_set_and_info(info, NOLOGREPLAY, 640 "disabling log replay at mount time"); 641 break; 642 case Opt_flushoncommit: 643 btrfs_set_and_info(info, FLUSHONCOMMIT, 644 "turning on flush-on-commit"); 645 break; 646 case Opt_noflushoncommit: 647 btrfs_clear_and_info(info, FLUSHONCOMMIT, 648 "turning off flush-on-commit"); 649 break; 650 case Opt_ratio: 651 ret = match_int(&args[0], &intarg); 652 if (ret) { 653 goto out; 654 } else if (intarg >= 0) { 655 info->metadata_ratio = intarg; 656 btrfs_info(info, "metadata ratio %d", 657 info->metadata_ratio); 658 } else { 659 ret = -EINVAL; 660 goto out; 661 } 662 break; 663 case Opt_discard: 664 btrfs_set_and_info(info, DISCARD, 665 "turning on discard"); 666 break; 667 case Opt_nodiscard: 668 btrfs_clear_and_info(info, DISCARD, 669 "turning off discard"); 670 break; 671 case Opt_space_cache: 672 case Opt_space_cache_version: 673 if (token == Opt_space_cache || 674 strcmp(args[0].from, "v1") == 0) { 675 btrfs_clear_opt(info->mount_opt, 676 FREE_SPACE_TREE); 677 btrfs_set_and_info(info, SPACE_CACHE, 678 "enabling disk space caching"); 679 } else if (strcmp(args[0].from, "v2") == 0) { 680 btrfs_clear_opt(info->mount_opt, 681 SPACE_CACHE); 682 btrfs_set_and_info(info, FREE_SPACE_TREE, 683 "enabling free space tree"); 684 } else { 685 ret = -EINVAL; 686 goto out; 687 } 688 break; 689 case Opt_rescan_uuid_tree: 690 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE); 691 break; 692 case Opt_no_space_cache: 693 if (btrfs_test_opt(info, SPACE_CACHE)) { 694 btrfs_clear_and_info(info, SPACE_CACHE, 695 "disabling disk space caching"); 696 } 697 if (btrfs_test_opt(info, FREE_SPACE_TREE)) { 698 btrfs_clear_and_info(info, FREE_SPACE_TREE, 699 "disabling free space tree"); 700 } 701 break; 702 case Opt_inode_cache: 703 btrfs_set_pending_and_info(info, INODE_MAP_CACHE, 704 "enabling inode map caching"); 705 break; 706 case Opt_noinode_cache: 707 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE, 708 "disabling inode map caching"); 709 break; 710 case Opt_clear_cache: 711 btrfs_set_and_info(info, CLEAR_CACHE, 712 "force clearing of disk cache"); 713 break; 714 case Opt_user_subvol_rm_allowed: 715 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 716 break; 717 case Opt_enospc_debug: 718 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 719 break; 720 case Opt_noenospc_debug: 721 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG); 722 break; 723 case Opt_defrag: 724 btrfs_set_and_info(info, AUTO_DEFRAG, 725 "enabling auto defrag"); 726 break; 727 case Opt_nodefrag: 728 btrfs_clear_and_info(info, AUTO_DEFRAG, 729 "disabling auto defrag"); 730 break; 731 case Opt_recovery: 732 btrfs_warn(info, 733 "'recovery' is deprecated, use 'usebackuproot' instead"); 734 case Opt_usebackuproot: 735 btrfs_info(info, 736 "trying to use backup root at mount time"); 737 btrfs_set_opt(info->mount_opt, USEBACKUPROOT); 738 break; 739 case Opt_skip_balance: 740 btrfs_set_opt(info->mount_opt, SKIP_BALANCE); 741 break; 742 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 743 case Opt_check_integrity_including_extent_data: 744 btrfs_info(info, 745 "enabling check integrity including extent data"); 746 btrfs_set_opt(info->mount_opt, 747 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); 748 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 749 break; 750 case Opt_check_integrity: 751 btrfs_info(info, "enabling check integrity"); 752 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 753 break; 754 case Opt_check_integrity_print_mask: 755 ret = match_int(&args[0], &intarg); 756 if (ret) { 757 goto out; 758 } else if (intarg >= 0) { 759 info->check_integrity_print_mask = intarg; 760 btrfs_info(info, 761 "check_integrity_print_mask 0x%x", 762 info->check_integrity_print_mask); 763 } else { 764 ret = -EINVAL; 765 goto out; 766 } 767 break; 768 #else 769 case Opt_check_integrity_including_extent_data: 770 case Opt_check_integrity: 771 case Opt_check_integrity_print_mask: 772 btrfs_err(info, 773 "support for check_integrity* not compiled in!"); 774 ret = -EINVAL; 775 goto out; 776 #endif 777 case Opt_fatal_errors: 778 if (strcmp(args[0].from, "panic") == 0) 779 btrfs_set_opt(info->mount_opt, 780 PANIC_ON_FATAL_ERROR); 781 else if (strcmp(args[0].from, "bug") == 0) 782 btrfs_clear_opt(info->mount_opt, 783 PANIC_ON_FATAL_ERROR); 784 else { 785 ret = -EINVAL; 786 goto out; 787 } 788 break; 789 case Opt_commit_interval: 790 intarg = 0; 791 ret = match_int(&args[0], &intarg); 792 if (ret < 0) { 793 btrfs_err(info, "invalid commit interval"); 794 ret = -EINVAL; 795 goto out; 796 } 797 if (intarg > 0) { 798 if (intarg > 300) { 799 btrfs_warn(info, 800 "excessive commit interval %d", 801 intarg); 802 } 803 info->commit_interval = intarg; 804 } else { 805 btrfs_info(info, 806 "using default commit interval %ds", 807 BTRFS_DEFAULT_COMMIT_INTERVAL); 808 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL; 809 } 810 break; 811 #ifdef CONFIG_BTRFS_DEBUG 812 case Opt_fragment_all: 813 btrfs_info(info, "fragmenting all space"); 814 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 815 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA); 816 break; 817 case Opt_fragment_metadata: 818 btrfs_info(info, "fragmenting metadata"); 819 btrfs_set_opt(info->mount_opt, 820 FRAGMENT_METADATA); 821 break; 822 case Opt_fragment_data: 823 btrfs_info(info, "fragmenting data"); 824 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 825 break; 826 #endif 827 case Opt_err: 828 btrfs_info(info, "unrecognized mount option '%s'", p); 829 ret = -EINVAL; 830 goto out; 831 default: 832 break; 833 } 834 } 835 check: 836 /* 837 * Extra check for current option against current flag 838 */ 839 if (btrfs_test_opt(info, NOLOGREPLAY) && !(new_flags & MS_RDONLY)) { 840 btrfs_err(info, 841 "nologreplay must be used with ro mount option"); 842 ret = -EINVAL; 843 } 844 out: 845 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) && 846 !btrfs_test_opt(info, FREE_SPACE_TREE) && 847 !btrfs_test_opt(info, CLEAR_CACHE)) { 848 btrfs_err(info, "cannot disable free space tree"); 849 ret = -EINVAL; 850 851 } 852 if (!ret && btrfs_test_opt(info, SPACE_CACHE)) 853 btrfs_info(info, "disk space caching is enabled"); 854 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE)) 855 btrfs_info(info, "using free space tree"); 856 kfree(orig); 857 return ret; 858 } 859 860 /* 861 * Parse mount options that are required early in the mount process. 862 * 863 * All other options will be parsed on much later in the mount process and 864 * only when we need to allocate a new super block. 865 */ 866 static int btrfs_parse_early_options(const char *options, fmode_t flags, 867 void *holder, char **subvol_name, u64 *subvol_objectid, 868 struct btrfs_fs_devices **fs_devices) 869 { 870 substring_t args[MAX_OPT_ARGS]; 871 char *device_name, *opts, *orig, *p; 872 char *num = NULL; 873 int error = 0; 874 875 if (!options) 876 return 0; 877 878 /* 879 * strsep changes the string, duplicate it because parse_options 880 * gets called twice 881 */ 882 opts = kstrdup(options, GFP_KERNEL); 883 if (!opts) 884 return -ENOMEM; 885 orig = opts; 886 887 while ((p = strsep(&opts, ",")) != NULL) { 888 int token; 889 if (!*p) 890 continue; 891 892 token = match_token(p, tokens, args); 893 switch (token) { 894 case Opt_subvol: 895 kfree(*subvol_name); 896 *subvol_name = match_strdup(&args[0]); 897 if (!*subvol_name) { 898 error = -ENOMEM; 899 goto out; 900 } 901 break; 902 case Opt_subvolid: 903 num = match_strdup(&args[0]); 904 if (num) { 905 *subvol_objectid = memparse(num, NULL); 906 kfree(num); 907 /* we want the original fs_tree */ 908 if (!*subvol_objectid) 909 *subvol_objectid = 910 BTRFS_FS_TREE_OBJECTID; 911 } else { 912 error = -EINVAL; 913 goto out; 914 } 915 break; 916 case Opt_subvolrootid: 917 pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n"); 918 break; 919 case Opt_device: 920 device_name = match_strdup(&args[0]); 921 if (!device_name) { 922 error = -ENOMEM; 923 goto out; 924 } 925 error = btrfs_scan_one_device(device_name, 926 flags, holder, fs_devices); 927 kfree(device_name); 928 if (error) 929 goto out; 930 break; 931 default: 932 break; 933 } 934 } 935 936 out: 937 kfree(orig); 938 return error; 939 } 940 941 static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, 942 u64 subvol_objectid) 943 { 944 struct btrfs_root *root = fs_info->tree_root; 945 struct btrfs_root *fs_root; 946 struct btrfs_root_ref *root_ref; 947 struct btrfs_inode_ref *inode_ref; 948 struct btrfs_key key; 949 struct btrfs_path *path = NULL; 950 char *name = NULL, *ptr; 951 u64 dirid; 952 int len; 953 int ret; 954 955 path = btrfs_alloc_path(); 956 if (!path) { 957 ret = -ENOMEM; 958 goto err; 959 } 960 path->leave_spinning = 1; 961 962 name = kmalloc(PATH_MAX, GFP_NOFS); 963 if (!name) { 964 ret = -ENOMEM; 965 goto err; 966 } 967 ptr = name + PATH_MAX - 1; 968 ptr[0] = '\0'; 969 970 /* 971 * Walk up the subvolume trees in the tree of tree roots by root 972 * backrefs until we hit the top-level subvolume. 973 */ 974 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) { 975 key.objectid = subvol_objectid; 976 key.type = BTRFS_ROOT_BACKREF_KEY; 977 key.offset = (u64)-1; 978 979 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 980 if (ret < 0) { 981 goto err; 982 } else if (ret > 0) { 983 ret = btrfs_previous_item(root, path, subvol_objectid, 984 BTRFS_ROOT_BACKREF_KEY); 985 if (ret < 0) { 986 goto err; 987 } else if (ret > 0) { 988 ret = -ENOENT; 989 goto err; 990 } 991 } 992 993 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 994 subvol_objectid = key.offset; 995 996 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 997 struct btrfs_root_ref); 998 len = btrfs_root_ref_name_len(path->nodes[0], root_ref); 999 ptr -= len + 1; 1000 if (ptr < name) { 1001 ret = -ENAMETOOLONG; 1002 goto err; 1003 } 1004 read_extent_buffer(path->nodes[0], ptr + 1, 1005 (unsigned long)(root_ref + 1), len); 1006 ptr[0] = '/'; 1007 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref); 1008 btrfs_release_path(path); 1009 1010 key.objectid = subvol_objectid; 1011 key.type = BTRFS_ROOT_ITEM_KEY; 1012 key.offset = (u64)-1; 1013 fs_root = btrfs_read_fs_root_no_name(fs_info, &key); 1014 if (IS_ERR(fs_root)) { 1015 ret = PTR_ERR(fs_root); 1016 goto err; 1017 } 1018 1019 /* 1020 * Walk up the filesystem tree by inode refs until we hit the 1021 * root directory. 1022 */ 1023 while (dirid != BTRFS_FIRST_FREE_OBJECTID) { 1024 key.objectid = dirid; 1025 key.type = BTRFS_INODE_REF_KEY; 1026 key.offset = (u64)-1; 1027 1028 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); 1029 if (ret < 0) { 1030 goto err; 1031 } else if (ret > 0) { 1032 ret = btrfs_previous_item(fs_root, path, dirid, 1033 BTRFS_INODE_REF_KEY); 1034 if (ret < 0) { 1035 goto err; 1036 } else if (ret > 0) { 1037 ret = -ENOENT; 1038 goto err; 1039 } 1040 } 1041 1042 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 1043 dirid = key.offset; 1044 1045 inode_ref = btrfs_item_ptr(path->nodes[0], 1046 path->slots[0], 1047 struct btrfs_inode_ref); 1048 len = btrfs_inode_ref_name_len(path->nodes[0], 1049 inode_ref); 1050 ptr -= len + 1; 1051 if (ptr < name) { 1052 ret = -ENAMETOOLONG; 1053 goto err; 1054 } 1055 read_extent_buffer(path->nodes[0], ptr + 1, 1056 (unsigned long)(inode_ref + 1), len); 1057 ptr[0] = '/'; 1058 btrfs_release_path(path); 1059 } 1060 } 1061 1062 btrfs_free_path(path); 1063 if (ptr == name + PATH_MAX - 1) { 1064 name[0] = '/'; 1065 name[1] = '\0'; 1066 } else { 1067 memmove(name, ptr, name + PATH_MAX - ptr); 1068 } 1069 return name; 1070 1071 err: 1072 btrfs_free_path(path); 1073 kfree(name); 1074 return ERR_PTR(ret); 1075 } 1076 1077 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid) 1078 { 1079 struct btrfs_root *root = fs_info->tree_root; 1080 struct btrfs_dir_item *di; 1081 struct btrfs_path *path; 1082 struct btrfs_key location; 1083 u64 dir_id; 1084 1085 path = btrfs_alloc_path(); 1086 if (!path) 1087 return -ENOMEM; 1088 path->leave_spinning = 1; 1089 1090 /* 1091 * Find the "default" dir item which points to the root item that we 1092 * will mount by default if we haven't been given a specific subvolume 1093 * to mount. 1094 */ 1095 dir_id = btrfs_super_root_dir(fs_info->super_copy); 1096 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 1097 if (IS_ERR(di)) { 1098 btrfs_free_path(path); 1099 return PTR_ERR(di); 1100 } 1101 if (!di) { 1102 /* 1103 * Ok the default dir item isn't there. This is weird since 1104 * it's always been there, but don't freak out, just try and 1105 * mount the top-level subvolume. 1106 */ 1107 btrfs_free_path(path); 1108 *objectid = BTRFS_FS_TREE_OBJECTID; 1109 return 0; 1110 } 1111 1112 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 1113 btrfs_free_path(path); 1114 *objectid = location.objectid; 1115 return 0; 1116 } 1117 1118 static int btrfs_fill_super(struct super_block *sb, 1119 struct btrfs_fs_devices *fs_devices, 1120 void *data) 1121 { 1122 struct inode *inode; 1123 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1124 struct btrfs_key key; 1125 int err; 1126 1127 sb->s_maxbytes = MAX_LFS_FILESIZE; 1128 sb->s_magic = BTRFS_SUPER_MAGIC; 1129 sb->s_op = &btrfs_super_ops; 1130 sb->s_d_op = &btrfs_dentry_operations; 1131 sb->s_export_op = &btrfs_export_ops; 1132 sb->s_xattr = btrfs_xattr_handlers; 1133 sb->s_time_gran = 1; 1134 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 1135 sb->s_flags |= MS_POSIXACL; 1136 #endif 1137 sb->s_flags |= MS_I_VERSION; 1138 sb->s_iflags |= SB_I_CGROUPWB; 1139 1140 err = super_setup_bdi(sb); 1141 if (err) { 1142 btrfs_err(fs_info, "super_setup_bdi failed"); 1143 return err; 1144 } 1145 1146 err = open_ctree(sb, fs_devices, (char *)data); 1147 if (err) { 1148 btrfs_err(fs_info, "open_ctree failed"); 1149 return err; 1150 } 1151 1152 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 1153 key.type = BTRFS_INODE_ITEM_KEY; 1154 key.offset = 0; 1155 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL); 1156 if (IS_ERR(inode)) { 1157 err = PTR_ERR(inode); 1158 goto fail_close; 1159 } 1160 1161 sb->s_root = d_make_root(inode); 1162 if (!sb->s_root) { 1163 err = -ENOMEM; 1164 goto fail_close; 1165 } 1166 1167 save_mount_options(sb, data); 1168 cleancache_init_fs(sb); 1169 sb->s_flags |= MS_ACTIVE; 1170 return 0; 1171 1172 fail_close: 1173 close_ctree(fs_info); 1174 return err; 1175 } 1176 1177 int btrfs_sync_fs(struct super_block *sb, int wait) 1178 { 1179 struct btrfs_trans_handle *trans; 1180 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1181 struct btrfs_root *root = fs_info->tree_root; 1182 1183 trace_btrfs_sync_fs(fs_info, wait); 1184 1185 if (!wait) { 1186 filemap_flush(fs_info->btree_inode->i_mapping); 1187 return 0; 1188 } 1189 1190 btrfs_wait_ordered_roots(fs_info, -1, 0, (u64)-1); 1191 1192 trans = btrfs_attach_transaction_barrier(root); 1193 if (IS_ERR(trans)) { 1194 /* no transaction, don't bother */ 1195 if (PTR_ERR(trans) == -ENOENT) { 1196 /* 1197 * Exit unless we have some pending changes 1198 * that need to go through commit 1199 */ 1200 if (fs_info->pending_changes == 0) 1201 return 0; 1202 /* 1203 * A non-blocking test if the fs is frozen. We must not 1204 * start a new transaction here otherwise a deadlock 1205 * happens. The pending operations are delayed to the 1206 * next commit after thawing. 1207 */ 1208 if (__sb_start_write(sb, SB_FREEZE_WRITE, false)) 1209 __sb_end_write(sb, SB_FREEZE_WRITE); 1210 else 1211 return 0; 1212 trans = btrfs_start_transaction(root, 0); 1213 } 1214 if (IS_ERR(trans)) 1215 return PTR_ERR(trans); 1216 } 1217 return btrfs_commit_transaction(trans); 1218 } 1219 1220 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) 1221 { 1222 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); 1223 char *compress_type; 1224 1225 if (btrfs_test_opt(info, DEGRADED)) 1226 seq_puts(seq, ",degraded"); 1227 if (btrfs_test_opt(info, NODATASUM)) 1228 seq_puts(seq, ",nodatasum"); 1229 if (btrfs_test_opt(info, NODATACOW)) 1230 seq_puts(seq, ",nodatacow"); 1231 if (btrfs_test_opt(info, NOBARRIER)) 1232 seq_puts(seq, ",nobarrier"); 1233 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) 1234 seq_printf(seq, ",max_inline=%llu", info->max_inline); 1235 if (info->alloc_start != 0) 1236 seq_printf(seq, ",alloc_start=%llu", info->alloc_start); 1237 if (info->thread_pool_size != min_t(unsigned long, 1238 num_online_cpus() + 2, 8)) 1239 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 1240 if (btrfs_test_opt(info, COMPRESS)) { 1241 if (info->compress_type == BTRFS_COMPRESS_ZLIB) 1242 compress_type = "zlib"; 1243 else 1244 compress_type = "lzo"; 1245 if (btrfs_test_opt(info, FORCE_COMPRESS)) 1246 seq_printf(seq, ",compress-force=%s", compress_type); 1247 else 1248 seq_printf(seq, ",compress=%s", compress_type); 1249 } 1250 if (btrfs_test_opt(info, NOSSD)) 1251 seq_puts(seq, ",nossd"); 1252 if (btrfs_test_opt(info, SSD_SPREAD)) 1253 seq_puts(seq, ",ssd_spread"); 1254 else if (btrfs_test_opt(info, SSD)) 1255 seq_puts(seq, ",ssd"); 1256 if (btrfs_test_opt(info, NOTREELOG)) 1257 seq_puts(seq, ",notreelog"); 1258 if (btrfs_test_opt(info, NOLOGREPLAY)) 1259 seq_puts(seq, ",nologreplay"); 1260 if (btrfs_test_opt(info, FLUSHONCOMMIT)) 1261 seq_puts(seq, ",flushoncommit"); 1262 if (btrfs_test_opt(info, DISCARD)) 1263 seq_puts(seq, ",discard"); 1264 if (!(info->sb->s_flags & MS_POSIXACL)) 1265 seq_puts(seq, ",noacl"); 1266 if (btrfs_test_opt(info, SPACE_CACHE)) 1267 seq_puts(seq, ",space_cache"); 1268 else if (btrfs_test_opt(info, FREE_SPACE_TREE)) 1269 seq_puts(seq, ",space_cache=v2"); 1270 else 1271 seq_puts(seq, ",nospace_cache"); 1272 if (btrfs_test_opt(info, RESCAN_UUID_TREE)) 1273 seq_puts(seq, ",rescan_uuid_tree"); 1274 if (btrfs_test_opt(info, CLEAR_CACHE)) 1275 seq_puts(seq, ",clear_cache"); 1276 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED)) 1277 seq_puts(seq, ",user_subvol_rm_allowed"); 1278 if (btrfs_test_opt(info, ENOSPC_DEBUG)) 1279 seq_puts(seq, ",enospc_debug"); 1280 if (btrfs_test_opt(info, AUTO_DEFRAG)) 1281 seq_puts(seq, ",autodefrag"); 1282 if (btrfs_test_opt(info, INODE_MAP_CACHE)) 1283 seq_puts(seq, ",inode_cache"); 1284 if (btrfs_test_opt(info, SKIP_BALANCE)) 1285 seq_puts(seq, ",skip_balance"); 1286 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 1287 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA)) 1288 seq_puts(seq, ",check_int_data"); 1289 else if (btrfs_test_opt(info, CHECK_INTEGRITY)) 1290 seq_puts(seq, ",check_int"); 1291 if (info->check_integrity_print_mask) 1292 seq_printf(seq, ",check_int_print_mask=%d", 1293 info->check_integrity_print_mask); 1294 #endif 1295 if (info->metadata_ratio) 1296 seq_printf(seq, ",metadata_ratio=%d", 1297 info->metadata_ratio); 1298 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR)) 1299 seq_puts(seq, ",fatal_errors=panic"); 1300 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) 1301 seq_printf(seq, ",commit=%d", info->commit_interval); 1302 #ifdef CONFIG_BTRFS_DEBUG 1303 if (btrfs_test_opt(info, FRAGMENT_DATA)) 1304 seq_puts(seq, ",fragment=data"); 1305 if (btrfs_test_opt(info, FRAGMENT_METADATA)) 1306 seq_puts(seq, ",fragment=metadata"); 1307 #endif 1308 seq_printf(seq, ",subvolid=%llu", 1309 BTRFS_I(d_inode(dentry))->root->root_key.objectid); 1310 seq_puts(seq, ",subvol="); 1311 seq_dentry(seq, dentry, " \t\n\\"); 1312 return 0; 1313 } 1314 1315 static int btrfs_test_super(struct super_block *s, void *data) 1316 { 1317 struct btrfs_fs_info *p = data; 1318 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1319 1320 return fs_info->fs_devices == p->fs_devices; 1321 } 1322 1323 static int btrfs_set_super(struct super_block *s, void *data) 1324 { 1325 int err = set_anon_super(s, data); 1326 if (!err) 1327 s->s_fs_info = data; 1328 return err; 1329 } 1330 1331 /* 1332 * subvolumes are identified by ino 256 1333 */ 1334 static inline int is_subvolume_inode(struct inode *inode) 1335 { 1336 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 1337 return 1; 1338 return 0; 1339 } 1340 1341 /* 1342 * This will add subvolid=0 to the argument string while removing any subvol= 1343 * and subvolid= arguments to make sure we get the top-level root for path 1344 * walking to the subvol we want. 1345 */ 1346 static char *setup_root_args(char *args) 1347 { 1348 char *buf, *dst, *sep; 1349 1350 if (!args) 1351 return kstrdup("subvolid=0", GFP_NOFS); 1352 1353 /* The worst case is that we add ",subvolid=0" to the end. */ 1354 buf = dst = kmalloc(strlen(args) + strlen(",subvolid=0") + 1, GFP_NOFS); 1355 if (!buf) 1356 return NULL; 1357 1358 while (1) { 1359 sep = strchrnul(args, ','); 1360 if (!strstarts(args, "subvol=") && 1361 !strstarts(args, "subvolid=")) { 1362 memcpy(dst, args, sep - args); 1363 dst += sep - args; 1364 *dst++ = ','; 1365 } 1366 if (*sep) 1367 args = sep + 1; 1368 else 1369 break; 1370 } 1371 strcpy(dst, "subvolid=0"); 1372 1373 return buf; 1374 } 1375 1376 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid, 1377 int flags, const char *device_name, 1378 char *data) 1379 { 1380 struct dentry *root; 1381 struct vfsmount *mnt = NULL; 1382 char *newargs; 1383 int ret; 1384 1385 newargs = setup_root_args(data); 1386 if (!newargs) { 1387 root = ERR_PTR(-ENOMEM); 1388 goto out; 1389 } 1390 1391 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs); 1392 if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) { 1393 if (flags & MS_RDONLY) { 1394 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, 1395 device_name, newargs); 1396 } else { 1397 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, 1398 device_name, newargs); 1399 if (IS_ERR(mnt)) { 1400 root = ERR_CAST(mnt); 1401 mnt = NULL; 1402 goto out; 1403 } 1404 1405 down_write(&mnt->mnt_sb->s_umount); 1406 ret = btrfs_remount(mnt->mnt_sb, &flags, NULL); 1407 up_write(&mnt->mnt_sb->s_umount); 1408 if (ret < 0) { 1409 root = ERR_PTR(ret); 1410 goto out; 1411 } 1412 } 1413 } 1414 if (IS_ERR(mnt)) { 1415 root = ERR_CAST(mnt); 1416 mnt = NULL; 1417 goto out; 1418 } 1419 1420 if (!subvol_name) { 1421 if (!subvol_objectid) { 1422 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb), 1423 &subvol_objectid); 1424 if (ret) { 1425 root = ERR_PTR(ret); 1426 goto out; 1427 } 1428 } 1429 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb), 1430 subvol_objectid); 1431 if (IS_ERR(subvol_name)) { 1432 root = ERR_CAST(subvol_name); 1433 subvol_name = NULL; 1434 goto out; 1435 } 1436 1437 } 1438 1439 root = mount_subtree(mnt, subvol_name); 1440 /* mount_subtree() drops our reference on the vfsmount. */ 1441 mnt = NULL; 1442 1443 if (!IS_ERR(root)) { 1444 struct super_block *s = root->d_sb; 1445 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1446 struct inode *root_inode = d_inode(root); 1447 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid; 1448 1449 ret = 0; 1450 if (!is_subvolume_inode(root_inode)) { 1451 btrfs_err(fs_info, "'%s' is not a valid subvolume", 1452 subvol_name); 1453 ret = -EINVAL; 1454 } 1455 if (subvol_objectid && root_objectid != subvol_objectid) { 1456 /* 1457 * This will also catch a race condition where a 1458 * subvolume which was passed by ID is renamed and 1459 * another subvolume is renamed over the old location. 1460 */ 1461 btrfs_err(fs_info, 1462 "subvol '%s' does not match subvolid %llu", 1463 subvol_name, subvol_objectid); 1464 ret = -EINVAL; 1465 } 1466 if (ret) { 1467 dput(root); 1468 root = ERR_PTR(ret); 1469 deactivate_locked_super(s); 1470 } 1471 } 1472 1473 out: 1474 mntput(mnt); 1475 kfree(newargs); 1476 kfree(subvol_name); 1477 return root; 1478 } 1479 1480 static int parse_security_options(char *orig_opts, 1481 struct security_mnt_opts *sec_opts) 1482 { 1483 char *secdata = NULL; 1484 int ret = 0; 1485 1486 secdata = alloc_secdata(); 1487 if (!secdata) 1488 return -ENOMEM; 1489 ret = security_sb_copy_data(orig_opts, secdata); 1490 if (ret) { 1491 free_secdata(secdata); 1492 return ret; 1493 } 1494 ret = security_sb_parse_opts_str(secdata, sec_opts); 1495 free_secdata(secdata); 1496 return ret; 1497 } 1498 1499 static int setup_security_options(struct btrfs_fs_info *fs_info, 1500 struct super_block *sb, 1501 struct security_mnt_opts *sec_opts) 1502 { 1503 int ret = 0; 1504 1505 /* 1506 * Call security_sb_set_mnt_opts() to check whether new sec_opts 1507 * is valid. 1508 */ 1509 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL); 1510 if (ret) 1511 return ret; 1512 1513 #ifdef CONFIG_SECURITY 1514 if (!fs_info->security_opts.num_mnt_opts) { 1515 /* first time security setup, copy sec_opts to fs_info */ 1516 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts)); 1517 } else { 1518 /* 1519 * Since SELinux (the only one supporting security_mnt_opts) 1520 * does NOT support changing context during remount/mount of 1521 * the same sb, this must be the same or part of the same 1522 * security options, just free it. 1523 */ 1524 security_free_mnt_opts(sec_opts); 1525 } 1526 #endif 1527 return ret; 1528 } 1529 1530 /* 1531 * Find a superblock for the given device / mount point. 1532 * 1533 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 1534 * for multiple device setup. Make sure to keep it in sync. 1535 */ 1536 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 1537 const char *device_name, void *data) 1538 { 1539 struct block_device *bdev = NULL; 1540 struct super_block *s; 1541 struct btrfs_fs_devices *fs_devices = NULL; 1542 struct btrfs_fs_info *fs_info = NULL; 1543 struct security_mnt_opts new_sec_opts; 1544 fmode_t mode = FMODE_READ; 1545 char *subvol_name = NULL; 1546 u64 subvol_objectid = 0; 1547 int error = 0; 1548 1549 if (!(flags & MS_RDONLY)) 1550 mode |= FMODE_WRITE; 1551 1552 error = btrfs_parse_early_options(data, mode, fs_type, 1553 &subvol_name, &subvol_objectid, 1554 &fs_devices); 1555 if (error) { 1556 kfree(subvol_name); 1557 return ERR_PTR(error); 1558 } 1559 1560 if (subvol_name || subvol_objectid != BTRFS_FS_TREE_OBJECTID) { 1561 /* mount_subvol() will free subvol_name. */ 1562 return mount_subvol(subvol_name, subvol_objectid, flags, 1563 device_name, data); 1564 } 1565 1566 security_init_mnt_opts(&new_sec_opts); 1567 if (data) { 1568 error = parse_security_options(data, &new_sec_opts); 1569 if (error) 1570 return ERR_PTR(error); 1571 } 1572 1573 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); 1574 if (error) 1575 goto error_sec_opts; 1576 1577 /* 1578 * Setup a dummy root and fs_info for test/set super. This is because 1579 * we don't actually fill this stuff out until open_ctree, but we need 1580 * it for searching for existing supers, so this lets us do that and 1581 * then open_ctree will properly initialize everything later. 1582 */ 1583 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); 1584 if (!fs_info) { 1585 error = -ENOMEM; 1586 goto error_sec_opts; 1587 } 1588 1589 fs_info->fs_devices = fs_devices; 1590 1591 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1592 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1593 security_init_mnt_opts(&fs_info->security_opts); 1594 if (!fs_info->super_copy || !fs_info->super_for_commit) { 1595 error = -ENOMEM; 1596 goto error_fs_info; 1597 } 1598 1599 error = btrfs_open_devices(fs_devices, mode, fs_type); 1600 if (error) 1601 goto error_fs_info; 1602 1603 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 1604 error = -EACCES; 1605 goto error_close_devices; 1606 } 1607 1608 bdev = fs_devices->latest_bdev; 1609 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC, 1610 fs_info); 1611 if (IS_ERR(s)) { 1612 error = PTR_ERR(s); 1613 goto error_close_devices; 1614 } 1615 1616 if (s->s_root) { 1617 btrfs_close_devices(fs_devices); 1618 free_fs_info(fs_info); 1619 if ((flags ^ s->s_flags) & MS_RDONLY) 1620 error = -EBUSY; 1621 } else { 1622 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); 1623 btrfs_sb(s)->bdev_holder = fs_type; 1624 error = btrfs_fill_super(s, fs_devices, data); 1625 } 1626 if (error) { 1627 deactivate_locked_super(s); 1628 goto error_sec_opts; 1629 } 1630 1631 fs_info = btrfs_sb(s); 1632 error = setup_security_options(fs_info, s, &new_sec_opts); 1633 if (error) { 1634 deactivate_locked_super(s); 1635 goto error_sec_opts; 1636 } 1637 1638 return dget(s->s_root); 1639 1640 error_close_devices: 1641 btrfs_close_devices(fs_devices); 1642 error_fs_info: 1643 free_fs_info(fs_info); 1644 error_sec_opts: 1645 security_free_mnt_opts(&new_sec_opts); 1646 return ERR_PTR(error); 1647 } 1648 1649 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, 1650 int new_pool_size, int old_pool_size) 1651 { 1652 if (new_pool_size == old_pool_size) 1653 return; 1654 1655 fs_info->thread_pool_size = new_pool_size; 1656 1657 btrfs_info(fs_info, "resize thread pool %d -> %d", 1658 old_pool_size, new_pool_size); 1659 1660 btrfs_workqueue_set_max(fs_info->workers, new_pool_size); 1661 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size); 1662 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size); 1663 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size); 1664 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size); 1665 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size); 1666 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers, 1667 new_pool_size); 1668 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size); 1669 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size); 1670 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size); 1671 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size); 1672 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers, 1673 new_pool_size); 1674 } 1675 1676 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info) 1677 { 1678 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1679 } 1680 1681 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info, 1682 unsigned long old_opts, int flags) 1683 { 1684 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1685 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1686 (flags & MS_RDONLY))) { 1687 /* wait for any defraggers to finish */ 1688 wait_event(fs_info->transaction_wait, 1689 (atomic_read(&fs_info->defrag_running) == 0)); 1690 if (flags & MS_RDONLY) 1691 sync_filesystem(fs_info->sb); 1692 } 1693 } 1694 1695 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info, 1696 unsigned long old_opts) 1697 { 1698 /* 1699 * We need to cleanup all defragable inodes if the autodefragment is 1700 * close or the filesystem is read only. 1701 */ 1702 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1703 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1704 (fs_info->sb->s_flags & MS_RDONLY))) { 1705 btrfs_cleanup_defrag_inodes(fs_info); 1706 } 1707 1708 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1709 } 1710 1711 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1712 { 1713 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1714 struct btrfs_root *root = fs_info->tree_root; 1715 unsigned old_flags = sb->s_flags; 1716 unsigned long old_opts = fs_info->mount_opt; 1717 unsigned long old_compress_type = fs_info->compress_type; 1718 u64 old_max_inline = fs_info->max_inline; 1719 u64 old_alloc_start = fs_info->alloc_start; 1720 int old_thread_pool_size = fs_info->thread_pool_size; 1721 unsigned int old_metadata_ratio = fs_info->metadata_ratio; 1722 int ret; 1723 1724 sync_filesystem(sb); 1725 btrfs_remount_prepare(fs_info); 1726 1727 if (data) { 1728 struct security_mnt_opts new_sec_opts; 1729 1730 security_init_mnt_opts(&new_sec_opts); 1731 ret = parse_security_options(data, &new_sec_opts); 1732 if (ret) 1733 goto restore; 1734 ret = setup_security_options(fs_info, sb, 1735 &new_sec_opts); 1736 if (ret) { 1737 security_free_mnt_opts(&new_sec_opts); 1738 goto restore; 1739 } 1740 } 1741 1742 ret = btrfs_parse_options(fs_info, data, *flags); 1743 if (ret) { 1744 ret = -EINVAL; 1745 goto restore; 1746 } 1747 1748 btrfs_remount_begin(fs_info, old_opts, *flags); 1749 btrfs_resize_thread_pool(fs_info, 1750 fs_info->thread_pool_size, old_thread_pool_size); 1751 1752 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1753 goto out; 1754 1755 if (*flags & MS_RDONLY) { 1756 /* 1757 * this also happens on 'umount -rf' or on shutdown, when 1758 * the filesystem is busy. 1759 */ 1760 cancel_work_sync(&fs_info->async_reclaim_work); 1761 1762 /* wait for the uuid_scan task to finish */ 1763 down(&fs_info->uuid_tree_rescan_sem); 1764 /* avoid complains from lockdep et al. */ 1765 up(&fs_info->uuid_tree_rescan_sem); 1766 1767 sb->s_flags |= MS_RDONLY; 1768 1769 /* 1770 * Setting MS_RDONLY will put the cleaner thread to 1771 * sleep at the next loop if it's already active. 1772 * If it's already asleep, we'll leave unused block 1773 * groups on disk until we're mounted read-write again 1774 * unless we clean them up here. 1775 */ 1776 btrfs_delete_unused_bgs(fs_info); 1777 1778 btrfs_dev_replace_suspend_for_unmount(fs_info); 1779 btrfs_scrub_cancel(fs_info); 1780 btrfs_pause_balance(fs_info); 1781 1782 ret = btrfs_commit_super(fs_info); 1783 if (ret) 1784 goto restore; 1785 } else { 1786 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { 1787 btrfs_err(fs_info, 1788 "Remounting read-write after error is not allowed"); 1789 ret = -EINVAL; 1790 goto restore; 1791 } 1792 if (fs_info->fs_devices->rw_devices == 0) { 1793 ret = -EACCES; 1794 goto restore; 1795 } 1796 1797 if (fs_info->fs_devices->missing_devices > 1798 fs_info->num_tolerated_disk_barrier_failures) { 1799 btrfs_warn(fs_info, 1800 "too many missing devices, writeable remount is not allowed"); 1801 ret = -EACCES; 1802 goto restore; 1803 } 1804 1805 if (btrfs_super_log_root(fs_info->super_copy) != 0) { 1806 ret = -EINVAL; 1807 goto restore; 1808 } 1809 1810 ret = btrfs_cleanup_fs_roots(fs_info); 1811 if (ret) 1812 goto restore; 1813 1814 /* recover relocation */ 1815 mutex_lock(&fs_info->cleaner_mutex); 1816 ret = btrfs_recover_relocation(root); 1817 mutex_unlock(&fs_info->cleaner_mutex); 1818 if (ret) 1819 goto restore; 1820 1821 ret = btrfs_resume_balance_async(fs_info); 1822 if (ret) 1823 goto restore; 1824 1825 ret = btrfs_resume_dev_replace_async(fs_info); 1826 if (ret) { 1827 btrfs_warn(fs_info, "failed to resume dev_replace"); 1828 goto restore; 1829 } 1830 1831 if (!fs_info->uuid_root) { 1832 btrfs_info(fs_info, "creating UUID tree"); 1833 ret = btrfs_create_uuid_tree(fs_info); 1834 if (ret) { 1835 btrfs_warn(fs_info, 1836 "failed to create the UUID tree %d", 1837 ret); 1838 goto restore; 1839 } 1840 } 1841 sb->s_flags &= ~MS_RDONLY; 1842 1843 set_bit(BTRFS_FS_OPEN, &fs_info->flags); 1844 } 1845 out: 1846 wake_up_process(fs_info->transaction_kthread); 1847 btrfs_remount_cleanup(fs_info, old_opts); 1848 return 0; 1849 1850 restore: 1851 /* We've hit an error - don't reset MS_RDONLY */ 1852 if (sb->s_flags & MS_RDONLY) 1853 old_flags |= MS_RDONLY; 1854 sb->s_flags = old_flags; 1855 fs_info->mount_opt = old_opts; 1856 fs_info->compress_type = old_compress_type; 1857 fs_info->max_inline = old_max_inline; 1858 mutex_lock(&fs_info->chunk_mutex); 1859 fs_info->alloc_start = old_alloc_start; 1860 mutex_unlock(&fs_info->chunk_mutex); 1861 btrfs_resize_thread_pool(fs_info, 1862 old_thread_pool_size, fs_info->thread_pool_size); 1863 fs_info->metadata_ratio = old_metadata_ratio; 1864 btrfs_remount_cleanup(fs_info, old_opts); 1865 return ret; 1866 } 1867 1868 /* Used to sort the devices by max_avail(descending sort) */ 1869 static int btrfs_cmp_device_free_bytes(const void *dev_info1, 1870 const void *dev_info2) 1871 { 1872 if (((struct btrfs_device_info *)dev_info1)->max_avail > 1873 ((struct btrfs_device_info *)dev_info2)->max_avail) 1874 return -1; 1875 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 1876 ((struct btrfs_device_info *)dev_info2)->max_avail) 1877 return 1; 1878 else 1879 return 0; 1880 } 1881 1882 /* 1883 * sort the devices by max_avail, in which max free extent size of each device 1884 * is stored.(Descending Sort) 1885 */ 1886 static inline void btrfs_descending_sort_devices( 1887 struct btrfs_device_info *devices, 1888 size_t nr_devices) 1889 { 1890 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1891 btrfs_cmp_device_free_bytes, NULL); 1892 } 1893 1894 /* 1895 * The helper to calc the free space on the devices that can be used to store 1896 * file data. 1897 */ 1898 static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info, 1899 u64 *free_bytes) 1900 { 1901 struct btrfs_root *root = fs_info->tree_root; 1902 struct btrfs_device_info *devices_info; 1903 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1904 struct btrfs_device *device; 1905 u64 skip_space; 1906 u64 type; 1907 u64 avail_space; 1908 u64 used_space; 1909 u64 min_stripe_size; 1910 int min_stripes = 1, num_stripes = 1; 1911 int i = 0, nr_devices; 1912 int ret; 1913 1914 /* 1915 * We aren't under the device list lock, so this is racy-ish, but good 1916 * enough for our purposes. 1917 */ 1918 nr_devices = fs_info->fs_devices->open_devices; 1919 if (!nr_devices) { 1920 smp_mb(); 1921 nr_devices = fs_info->fs_devices->open_devices; 1922 ASSERT(nr_devices); 1923 if (!nr_devices) { 1924 *free_bytes = 0; 1925 return 0; 1926 } 1927 } 1928 1929 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info), 1930 GFP_NOFS); 1931 if (!devices_info) 1932 return -ENOMEM; 1933 1934 /* calc min stripe number for data space allocation */ 1935 type = btrfs_get_alloc_profile(root, 1); 1936 if (type & BTRFS_BLOCK_GROUP_RAID0) { 1937 min_stripes = 2; 1938 num_stripes = nr_devices; 1939 } else if (type & BTRFS_BLOCK_GROUP_RAID1) { 1940 min_stripes = 2; 1941 num_stripes = 2; 1942 } else if (type & BTRFS_BLOCK_GROUP_RAID10) { 1943 min_stripes = 4; 1944 num_stripes = 4; 1945 } 1946 1947 if (type & BTRFS_BLOCK_GROUP_DUP) 1948 min_stripe_size = 2 * BTRFS_STRIPE_LEN; 1949 else 1950 min_stripe_size = BTRFS_STRIPE_LEN; 1951 1952 if (fs_info->alloc_start) 1953 mutex_lock(&fs_devices->device_list_mutex); 1954 rcu_read_lock(); 1955 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { 1956 if (!device->in_fs_metadata || !device->bdev || 1957 device->is_tgtdev_for_dev_replace) 1958 continue; 1959 1960 if (i >= nr_devices) 1961 break; 1962 1963 avail_space = device->total_bytes - device->bytes_used; 1964 1965 /* align with stripe_len */ 1966 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN); 1967 avail_space *= BTRFS_STRIPE_LEN; 1968 1969 /* 1970 * In order to avoid overwriting the superblock on the drive, 1971 * btrfs starts at an offset of at least 1MB when doing chunk 1972 * allocation. 1973 */ 1974 skip_space = SZ_1M; 1975 1976 /* user can set the offset in fs_info->alloc_start. */ 1977 if (fs_info->alloc_start && 1978 fs_info->alloc_start + BTRFS_STRIPE_LEN <= 1979 device->total_bytes) { 1980 rcu_read_unlock(); 1981 skip_space = max(fs_info->alloc_start, skip_space); 1982 1983 /* 1984 * btrfs can not use the free space in 1985 * [0, skip_space - 1], we must subtract it from the 1986 * total. In order to implement it, we account the used 1987 * space in this range first. 1988 */ 1989 ret = btrfs_account_dev_extents_size(device, 0, 1990 skip_space - 1, 1991 &used_space); 1992 if (ret) { 1993 kfree(devices_info); 1994 mutex_unlock(&fs_devices->device_list_mutex); 1995 return ret; 1996 } 1997 1998 rcu_read_lock(); 1999 2000 /* calc the free space in [0, skip_space - 1] */ 2001 skip_space -= used_space; 2002 } 2003 2004 /* 2005 * we can use the free space in [0, skip_space - 1], subtract 2006 * it from the total. 2007 */ 2008 if (avail_space && avail_space >= skip_space) 2009 avail_space -= skip_space; 2010 else 2011 avail_space = 0; 2012 2013 if (avail_space < min_stripe_size) 2014 continue; 2015 2016 devices_info[i].dev = device; 2017 devices_info[i].max_avail = avail_space; 2018 2019 i++; 2020 } 2021 rcu_read_unlock(); 2022 if (fs_info->alloc_start) 2023 mutex_unlock(&fs_devices->device_list_mutex); 2024 2025 nr_devices = i; 2026 2027 btrfs_descending_sort_devices(devices_info, nr_devices); 2028 2029 i = nr_devices - 1; 2030 avail_space = 0; 2031 while (nr_devices >= min_stripes) { 2032 if (num_stripes > nr_devices) 2033 num_stripes = nr_devices; 2034 2035 if (devices_info[i].max_avail >= min_stripe_size) { 2036 int j; 2037 u64 alloc_size; 2038 2039 avail_space += devices_info[i].max_avail * num_stripes; 2040 alloc_size = devices_info[i].max_avail; 2041 for (j = i + 1 - num_stripes; j <= i; j++) 2042 devices_info[j].max_avail -= alloc_size; 2043 } 2044 i--; 2045 nr_devices--; 2046 } 2047 2048 kfree(devices_info); 2049 *free_bytes = avail_space; 2050 return 0; 2051 } 2052 2053 /* 2054 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles. 2055 * 2056 * If there's a redundant raid level at DATA block groups, use the respective 2057 * multiplier to scale the sizes. 2058 * 2059 * Unused device space usage is based on simulating the chunk allocator 2060 * algorithm that respects the device sizes, order of allocations and the 2061 * 'alloc_start' value, this is a close approximation of the actual use but 2062 * there are other factors that may change the result (like a new metadata 2063 * chunk). 2064 * 2065 * If metadata is exhausted, f_bavail will be 0. 2066 */ 2067 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 2068 { 2069 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); 2070 struct btrfs_super_block *disk_super = fs_info->super_copy; 2071 struct list_head *head = &fs_info->space_info; 2072 struct btrfs_space_info *found; 2073 u64 total_used = 0; 2074 u64 total_free_data = 0; 2075 u64 total_free_meta = 0; 2076 int bits = dentry->d_sb->s_blocksize_bits; 2077 __be32 *fsid = (__be32 *)fs_info->fsid; 2078 unsigned factor = 1; 2079 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 2080 int ret; 2081 u64 thresh = 0; 2082 int mixed = 0; 2083 2084 rcu_read_lock(); 2085 list_for_each_entry_rcu(found, head, list) { 2086 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 2087 int i; 2088 2089 total_free_data += found->disk_total - found->disk_used; 2090 total_free_data -= 2091 btrfs_account_ro_block_groups_free_space(found); 2092 2093 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { 2094 if (!list_empty(&found->block_groups[i])) { 2095 switch (i) { 2096 case BTRFS_RAID_DUP: 2097 case BTRFS_RAID_RAID1: 2098 case BTRFS_RAID_RAID10: 2099 factor = 2; 2100 } 2101 } 2102 } 2103 } 2104 2105 /* 2106 * Metadata in mixed block goup profiles are accounted in data 2107 */ 2108 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) { 2109 if (found->flags & BTRFS_BLOCK_GROUP_DATA) 2110 mixed = 1; 2111 else 2112 total_free_meta += found->disk_total - 2113 found->disk_used; 2114 } 2115 2116 total_used += found->disk_used; 2117 } 2118 2119 rcu_read_unlock(); 2120 2121 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor); 2122 buf->f_blocks >>= bits; 2123 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits); 2124 2125 /* Account global block reserve as used, it's in logical size already */ 2126 spin_lock(&block_rsv->lock); 2127 /* Mixed block groups accounting is not byte-accurate, avoid overflow */ 2128 if (buf->f_bfree >= block_rsv->size >> bits) 2129 buf->f_bfree -= block_rsv->size >> bits; 2130 else 2131 buf->f_bfree = 0; 2132 spin_unlock(&block_rsv->lock); 2133 2134 buf->f_bavail = div_u64(total_free_data, factor); 2135 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data); 2136 if (ret) 2137 return ret; 2138 buf->f_bavail += div_u64(total_free_data, factor); 2139 buf->f_bavail = buf->f_bavail >> bits; 2140 2141 /* 2142 * We calculate the remaining metadata space minus global reserve. If 2143 * this is (supposedly) smaller than zero, there's no space. But this 2144 * does not hold in practice, the exhausted state happens where's still 2145 * some positive delta. So we apply some guesswork and compare the 2146 * delta to a 4M threshold. (Practically observed delta was ~2M.) 2147 * 2148 * We probably cannot calculate the exact threshold value because this 2149 * depends on the internal reservations requested by various 2150 * operations, so some operations that consume a few metadata will 2151 * succeed even if the Avail is zero. But this is better than the other 2152 * way around. 2153 */ 2154 thresh = 4 * 1024 * 1024; 2155 2156 if (!mixed && total_free_meta - thresh < block_rsv->size) 2157 buf->f_bavail = 0; 2158 2159 buf->f_type = BTRFS_SUPER_MAGIC; 2160 buf->f_bsize = dentry->d_sb->s_blocksize; 2161 buf->f_namelen = BTRFS_NAME_LEN; 2162 2163 /* We treat it as constant endianness (it doesn't matter _which_) 2164 because we want the fsid to come out the same whether mounted 2165 on a big-endian or little-endian host */ 2166 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 2167 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 2168 /* Mask in the root object ID too, to disambiguate subvols */ 2169 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32; 2170 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid; 2171 2172 return 0; 2173 } 2174 2175 static void btrfs_kill_super(struct super_block *sb) 2176 { 2177 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2178 kill_anon_super(sb); 2179 free_fs_info(fs_info); 2180 } 2181 2182 static struct file_system_type btrfs_fs_type = { 2183 .owner = THIS_MODULE, 2184 .name = "btrfs", 2185 .mount = btrfs_mount, 2186 .kill_sb = btrfs_kill_super, 2187 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, 2188 }; 2189 MODULE_ALIAS_FS("btrfs"); 2190 2191 static int btrfs_control_open(struct inode *inode, struct file *file) 2192 { 2193 /* 2194 * The control file's private_data is used to hold the 2195 * transaction when it is started and is used to keep 2196 * track of whether a transaction is already in progress. 2197 */ 2198 file->private_data = NULL; 2199 return 0; 2200 } 2201 2202 /* 2203 * used by btrfsctl to scan devices when no FS is mounted 2204 */ 2205 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 2206 unsigned long arg) 2207 { 2208 struct btrfs_ioctl_vol_args *vol; 2209 struct btrfs_fs_devices *fs_devices; 2210 int ret = -ENOTTY; 2211 2212 if (!capable(CAP_SYS_ADMIN)) 2213 return -EPERM; 2214 2215 vol = memdup_user((void __user *)arg, sizeof(*vol)); 2216 if (IS_ERR(vol)) 2217 return PTR_ERR(vol); 2218 2219 switch (cmd) { 2220 case BTRFS_IOC_SCAN_DEV: 2221 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 2222 &btrfs_fs_type, &fs_devices); 2223 break; 2224 case BTRFS_IOC_DEVICES_READY: 2225 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 2226 &btrfs_fs_type, &fs_devices); 2227 if (ret) 2228 break; 2229 ret = !(fs_devices->num_devices == fs_devices->total_devices); 2230 break; 2231 case BTRFS_IOC_GET_SUPPORTED_FEATURES: 2232 ret = btrfs_ioctl_get_supported_features((void __user*)arg); 2233 break; 2234 } 2235 2236 kfree(vol); 2237 return ret; 2238 } 2239 2240 static int btrfs_freeze(struct super_block *sb) 2241 { 2242 struct btrfs_trans_handle *trans; 2243 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2244 struct btrfs_root *root = fs_info->tree_root; 2245 2246 fs_info->fs_frozen = 1; 2247 /* 2248 * We don't need a barrier here, we'll wait for any transaction that 2249 * could be in progress on other threads (and do delayed iputs that 2250 * we want to avoid on a frozen filesystem), or do the commit 2251 * ourselves. 2252 */ 2253 trans = btrfs_attach_transaction_barrier(root); 2254 if (IS_ERR(trans)) { 2255 /* no transaction, don't bother */ 2256 if (PTR_ERR(trans) == -ENOENT) 2257 return 0; 2258 return PTR_ERR(trans); 2259 } 2260 return btrfs_commit_transaction(trans); 2261 } 2262 2263 static int btrfs_unfreeze(struct super_block *sb) 2264 { 2265 btrfs_sb(sb)->fs_frozen = 0; 2266 return 0; 2267 } 2268 2269 static int btrfs_show_devname(struct seq_file *m, struct dentry *root) 2270 { 2271 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); 2272 struct btrfs_fs_devices *cur_devices; 2273 struct btrfs_device *dev, *first_dev = NULL; 2274 struct list_head *head; 2275 struct rcu_string *name; 2276 2277 mutex_lock(&fs_info->fs_devices->device_list_mutex); 2278 cur_devices = fs_info->fs_devices; 2279 while (cur_devices) { 2280 head = &cur_devices->devices; 2281 list_for_each_entry(dev, head, dev_list) { 2282 if (dev->missing) 2283 continue; 2284 if (!dev->name) 2285 continue; 2286 if (!first_dev || dev->devid < first_dev->devid) 2287 first_dev = dev; 2288 } 2289 cur_devices = cur_devices->seed; 2290 } 2291 2292 if (first_dev) { 2293 rcu_read_lock(); 2294 name = rcu_dereference(first_dev->name); 2295 seq_escape(m, name->str, " \t\n\\"); 2296 rcu_read_unlock(); 2297 } else { 2298 WARN_ON(1); 2299 } 2300 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2301 return 0; 2302 } 2303 2304 static const struct super_operations btrfs_super_ops = { 2305 .drop_inode = btrfs_drop_inode, 2306 .evict_inode = btrfs_evict_inode, 2307 .put_super = btrfs_put_super, 2308 .sync_fs = btrfs_sync_fs, 2309 .show_options = btrfs_show_options, 2310 .show_devname = btrfs_show_devname, 2311 .write_inode = btrfs_write_inode, 2312 .alloc_inode = btrfs_alloc_inode, 2313 .destroy_inode = btrfs_destroy_inode, 2314 .statfs = btrfs_statfs, 2315 .remount_fs = btrfs_remount, 2316 .freeze_fs = btrfs_freeze, 2317 .unfreeze_fs = btrfs_unfreeze, 2318 }; 2319 2320 static const struct file_operations btrfs_ctl_fops = { 2321 .open = btrfs_control_open, 2322 .unlocked_ioctl = btrfs_control_ioctl, 2323 .compat_ioctl = btrfs_control_ioctl, 2324 .owner = THIS_MODULE, 2325 .llseek = noop_llseek, 2326 }; 2327 2328 static struct miscdevice btrfs_misc = { 2329 .minor = BTRFS_MINOR, 2330 .name = "btrfs-control", 2331 .fops = &btrfs_ctl_fops 2332 }; 2333 2334 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 2335 MODULE_ALIAS("devname:btrfs-control"); 2336 2337 static int btrfs_interface_init(void) 2338 { 2339 return misc_register(&btrfs_misc); 2340 } 2341 2342 static void btrfs_interface_exit(void) 2343 { 2344 misc_deregister(&btrfs_misc); 2345 } 2346 2347 static void btrfs_print_mod_info(void) 2348 { 2349 pr_info("Btrfs loaded, crc32c=%s" 2350 #ifdef CONFIG_BTRFS_DEBUG 2351 ", debug=on" 2352 #endif 2353 #ifdef CONFIG_BTRFS_ASSERT 2354 ", assert=on" 2355 #endif 2356 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 2357 ", integrity-checker=on" 2358 #endif 2359 "\n", 2360 btrfs_crc32c_impl()); 2361 } 2362 2363 static int __init init_btrfs_fs(void) 2364 { 2365 int err; 2366 2367 err = btrfs_hash_init(); 2368 if (err) 2369 return err; 2370 2371 btrfs_props_init(); 2372 2373 err = btrfs_init_sysfs(); 2374 if (err) 2375 goto free_hash; 2376 2377 btrfs_init_compress(); 2378 2379 err = btrfs_init_cachep(); 2380 if (err) 2381 goto free_compress; 2382 2383 err = extent_io_init(); 2384 if (err) 2385 goto free_cachep; 2386 2387 err = extent_map_init(); 2388 if (err) 2389 goto free_extent_io; 2390 2391 err = ordered_data_init(); 2392 if (err) 2393 goto free_extent_map; 2394 2395 err = btrfs_delayed_inode_init(); 2396 if (err) 2397 goto free_ordered_data; 2398 2399 err = btrfs_auto_defrag_init(); 2400 if (err) 2401 goto free_delayed_inode; 2402 2403 err = btrfs_delayed_ref_init(); 2404 if (err) 2405 goto free_auto_defrag; 2406 2407 err = btrfs_prelim_ref_init(); 2408 if (err) 2409 goto free_delayed_ref; 2410 2411 err = btrfs_end_io_wq_init(); 2412 if (err) 2413 goto free_prelim_ref; 2414 2415 err = btrfs_interface_init(); 2416 if (err) 2417 goto free_end_io_wq; 2418 2419 btrfs_init_lockdep(); 2420 2421 btrfs_print_mod_info(); 2422 2423 err = btrfs_run_sanity_tests(); 2424 if (err) 2425 goto unregister_ioctl; 2426 2427 err = register_filesystem(&btrfs_fs_type); 2428 if (err) 2429 goto unregister_ioctl; 2430 2431 return 0; 2432 2433 unregister_ioctl: 2434 btrfs_interface_exit(); 2435 free_end_io_wq: 2436 btrfs_end_io_wq_exit(); 2437 free_prelim_ref: 2438 btrfs_prelim_ref_exit(); 2439 free_delayed_ref: 2440 btrfs_delayed_ref_exit(); 2441 free_auto_defrag: 2442 btrfs_auto_defrag_exit(); 2443 free_delayed_inode: 2444 btrfs_delayed_inode_exit(); 2445 free_ordered_data: 2446 ordered_data_exit(); 2447 free_extent_map: 2448 extent_map_exit(); 2449 free_extent_io: 2450 extent_io_exit(); 2451 free_cachep: 2452 btrfs_destroy_cachep(); 2453 free_compress: 2454 btrfs_exit_compress(); 2455 btrfs_exit_sysfs(); 2456 free_hash: 2457 btrfs_hash_exit(); 2458 return err; 2459 } 2460 2461 static void __exit exit_btrfs_fs(void) 2462 { 2463 btrfs_destroy_cachep(); 2464 btrfs_delayed_ref_exit(); 2465 btrfs_auto_defrag_exit(); 2466 btrfs_delayed_inode_exit(); 2467 btrfs_prelim_ref_exit(); 2468 ordered_data_exit(); 2469 extent_map_exit(); 2470 extent_io_exit(); 2471 btrfs_interface_exit(); 2472 btrfs_end_io_wq_exit(); 2473 unregister_filesystem(&btrfs_fs_type); 2474 btrfs_exit_sysfs(); 2475 btrfs_cleanup_fs_uuids(); 2476 btrfs_exit_compress(); 2477 btrfs_hash_exit(); 2478 } 2479 2480 late_initcall(init_btrfs_fs); 2481 module_exit(exit_btrfs_fs) 2482 2483 MODULE_LICENSE("GPL"); 2484