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 btrfs_info(info, 605 "option alloc_start is obsolete, ignored"); 606 break; 607 case Opt_acl: 608 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 609 info->sb->s_flags |= MS_POSIXACL; 610 break; 611 #else 612 btrfs_err(info, "support for ACL not compiled in!"); 613 ret = -EINVAL; 614 goto out; 615 #endif 616 case Opt_noacl: 617 info->sb->s_flags &= ~MS_POSIXACL; 618 break; 619 case Opt_notreelog: 620 btrfs_set_and_info(info, NOTREELOG, 621 "disabling tree log"); 622 break; 623 case Opt_treelog: 624 btrfs_clear_and_info(info, NOTREELOG, 625 "enabling tree log"); 626 break; 627 case Opt_norecovery: 628 case Opt_nologreplay: 629 btrfs_set_and_info(info, NOLOGREPLAY, 630 "disabling log replay at mount time"); 631 break; 632 case Opt_flushoncommit: 633 btrfs_set_and_info(info, FLUSHONCOMMIT, 634 "turning on flush-on-commit"); 635 break; 636 case Opt_noflushoncommit: 637 btrfs_clear_and_info(info, FLUSHONCOMMIT, 638 "turning off flush-on-commit"); 639 break; 640 case Opt_ratio: 641 ret = match_int(&args[0], &intarg); 642 if (ret) { 643 goto out; 644 } else if (intarg >= 0) { 645 info->metadata_ratio = intarg; 646 btrfs_info(info, "metadata ratio %d", 647 info->metadata_ratio); 648 } else { 649 ret = -EINVAL; 650 goto out; 651 } 652 break; 653 case Opt_discard: 654 btrfs_set_and_info(info, DISCARD, 655 "turning on discard"); 656 break; 657 case Opt_nodiscard: 658 btrfs_clear_and_info(info, DISCARD, 659 "turning off discard"); 660 break; 661 case Opt_space_cache: 662 case Opt_space_cache_version: 663 if (token == Opt_space_cache || 664 strcmp(args[0].from, "v1") == 0) { 665 btrfs_clear_opt(info->mount_opt, 666 FREE_SPACE_TREE); 667 btrfs_set_and_info(info, SPACE_CACHE, 668 "enabling disk space caching"); 669 } else if (strcmp(args[0].from, "v2") == 0) { 670 btrfs_clear_opt(info->mount_opt, 671 SPACE_CACHE); 672 btrfs_set_and_info(info, FREE_SPACE_TREE, 673 "enabling free space tree"); 674 } else { 675 ret = -EINVAL; 676 goto out; 677 } 678 break; 679 case Opt_rescan_uuid_tree: 680 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE); 681 break; 682 case Opt_no_space_cache: 683 if (btrfs_test_opt(info, SPACE_CACHE)) { 684 btrfs_clear_and_info(info, SPACE_CACHE, 685 "disabling disk space caching"); 686 } 687 if (btrfs_test_opt(info, FREE_SPACE_TREE)) { 688 btrfs_clear_and_info(info, FREE_SPACE_TREE, 689 "disabling free space tree"); 690 } 691 break; 692 case Opt_inode_cache: 693 btrfs_set_pending_and_info(info, INODE_MAP_CACHE, 694 "enabling inode map caching"); 695 break; 696 case Opt_noinode_cache: 697 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE, 698 "disabling inode map caching"); 699 break; 700 case Opt_clear_cache: 701 btrfs_set_and_info(info, CLEAR_CACHE, 702 "force clearing of disk cache"); 703 break; 704 case Opt_user_subvol_rm_allowed: 705 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 706 break; 707 case Opt_enospc_debug: 708 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 709 break; 710 case Opt_noenospc_debug: 711 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG); 712 break; 713 case Opt_defrag: 714 btrfs_set_and_info(info, AUTO_DEFRAG, 715 "enabling auto defrag"); 716 break; 717 case Opt_nodefrag: 718 btrfs_clear_and_info(info, AUTO_DEFRAG, 719 "disabling auto defrag"); 720 break; 721 case Opt_recovery: 722 btrfs_warn(info, 723 "'recovery' is deprecated, use 'usebackuproot' instead"); 724 case Opt_usebackuproot: 725 btrfs_info(info, 726 "trying to use backup root at mount time"); 727 btrfs_set_opt(info->mount_opt, USEBACKUPROOT); 728 break; 729 case Opt_skip_balance: 730 btrfs_set_opt(info->mount_opt, SKIP_BALANCE); 731 break; 732 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 733 case Opt_check_integrity_including_extent_data: 734 btrfs_info(info, 735 "enabling check integrity including extent data"); 736 btrfs_set_opt(info->mount_opt, 737 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); 738 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 739 break; 740 case Opt_check_integrity: 741 btrfs_info(info, "enabling check integrity"); 742 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 743 break; 744 case Opt_check_integrity_print_mask: 745 ret = match_int(&args[0], &intarg); 746 if (ret) { 747 goto out; 748 } else if (intarg >= 0) { 749 info->check_integrity_print_mask = intarg; 750 btrfs_info(info, 751 "check_integrity_print_mask 0x%x", 752 info->check_integrity_print_mask); 753 } else { 754 ret = -EINVAL; 755 goto out; 756 } 757 break; 758 #else 759 case Opt_check_integrity_including_extent_data: 760 case Opt_check_integrity: 761 case Opt_check_integrity_print_mask: 762 btrfs_err(info, 763 "support for check_integrity* not compiled in!"); 764 ret = -EINVAL; 765 goto out; 766 #endif 767 case Opt_fatal_errors: 768 if (strcmp(args[0].from, "panic") == 0) 769 btrfs_set_opt(info->mount_opt, 770 PANIC_ON_FATAL_ERROR); 771 else if (strcmp(args[0].from, "bug") == 0) 772 btrfs_clear_opt(info->mount_opt, 773 PANIC_ON_FATAL_ERROR); 774 else { 775 ret = -EINVAL; 776 goto out; 777 } 778 break; 779 case Opt_commit_interval: 780 intarg = 0; 781 ret = match_int(&args[0], &intarg); 782 if (ret < 0) { 783 btrfs_err(info, "invalid commit interval"); 784 ret = -EINVAL; 785 goto out; 786 } 787 if (intarg > 0) { 788 if (intarg > 300) { 789 btrfs_warn(info, 790 "excessive commit interval %d", 791 intarg); 792 } 793 info->commit_interval = intarg; 794 } else { 795 btrfs_info(info, 796 "using default commit interval %ds", 797 BTRFS_DEFAULT_COMMIT_INTERVAL); 798 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL; 799 } 800 break; 801 #ifdef CONFIG_BTRFS_DEBUG 802 case Opt_fragment_all: 803 btrfs_info(info, "fragmenting all space"); 804 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 805 btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA); 806 break; 807 case Opt_fragment_metadata: 808 btrfs_info(info, "fragmenting metadata"); 809 btrfs_set_opt(info->mount_opt, 810 FRAGMENT_METADATA); 811 break; 812 case Opt_fragment_data: 813 btrfs_info(info, "fragmenting data"); 814 btrfs_set_opt(info->mount_opt, FRAGMENT_DATA); 815 break; 816 #endif 817 case Opt_err: 818 btrfs_info(info, "unrecognized mount option '%s'", p); 819 ret = -EINVAL; 820 goto out; 821 default: 822 break; 823 } 824 } 825 check: 826 /* 827 * Extra check for current option against current flag 828 */ 829 if (btrfs_test_opt(info, NOLOGREPLAY) && !(new_flags & MS_RDONLY)) { 830 btrfs_err(info, 831 "nologreplay must be used with ro mount option"); 832 ret = -EINVAL; 833 } 834 out: 835 if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) && 836 !btrfs_test_opt(info, FREE_SPACE_TREE) && 837 !btrfs_test_opt(info, CLEAR_CACHE)) { 838 btrfs_err(info, "cannot disable free space tree"); 839 ret = -EINVAL; 840 841 } 842 if (!ret && btrfs_test_opt(info, SPACE_CACHE)) 843 btrfs_info(info, "disk space caching is enabled"); 844 if (!ret && btrfs_test_opt(info, FREE_SPACE_TREE)) 845 btrfs_info(info, "using free space tree"); 846 kfree(orig); 847 return ret; 848 } 849 850 /* 851 * Parse mount options that are required early in the mount process. 852 * 853 * All other options will be parsed on much later in the mount process and 854 * only when we need to allocate a new super block. 855 */ 856 static int btrfs_parse_early_options(const char *options, fmode_t flags, 857 void *holder, char **subvol_name, u64 *subvol_objectid, 858 struct btrfs_fs_devices **fs_devices) 859 { 860 substring_t args[MAX_OPT_ARGS]; 861 char *device_name, *opts, *orig, *p; 862 char *num = NULL; 863 int error = 0; 864 865 if (!options) 866 return 0; 867 868 /* 869 * strsep changes the string, duplicate it because parse_options 870 * gets called twice 871 */ 872 opts = kstrdup(options, GFP_KERNEL); 873 if (!opts) 874 return -ENOMEM; 875 orig = opts; 876 877 while ((p = strsep(&opts, ",")) != NULL) { 878 int token; 879 if (!*p) 880 continue; 881 882 token = match_token(p, tokens, args); 883 switch (token) { 884 case Opt_subvol: 885 kfree(*subvol_name); 886 *subvol_name = match_strdup(&args[0]); 887 if (!*subvol_name) { 888 error = -ENOMEM; 889 goto out; 890 } 891 break; 892 case Opt_subvolid: 893 num = match_strdup(&args[0]); 894 if (num) { 895 *subvol_objectid = memparse(num, NULL); 896 kfree(num); 897 /* we want the original fs_tree */ 898 if (!*subvol_objectid) 899 *subvol_objectid = 900 BTRFS_FS_TREE_OBJECTID; 901 } else { 902 error = -EINVAL; 903 goto out; 904 } 905 break; 906 case Opt_subvolrootid: 907 pr_warn("BTRFS: 'subvolrootid' mount option is deprecated and has no effect\n"); 908 break; 909 case Opt_device: 910 device_name = match_strdup(&args[0]); 911 if (!device_name) { 912 error = -ENOMEM; 913 goto out; 914 } 915 error = btrfs_scan_one_device(device_name, 916 flags, holder, fs_devices); 917 kfree(device_name); 918 if (error) 919 goto out; 920 break; 921 default: 922 break; 923 } 924 } 925 926 out: 927 kfree(orig); 928 return error; 929 } 930 931 static char *get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info, 932 u64 subvol_objectid) 933 { 934 struct btrfs_root *root = fs_info->tree_root; 935 struct btrfs_root *fs_root; 936 struct btrfs_root_ref *root_ref; 937 struct btrfs_inode_ref *inode_ref; 938 struct btrfs_key key; 939 struct btrfs_path *path = NULL; 940 char *name = NULL, *ptr; 941 u64 dirid; 942 int len; 943 int ret; 944 945 path = btrfs_alloc_path(); 946 if (!path) { 947 ret = -ENOMEM; 948 goto err; 949 } 950 path->leave_spinning = 1; 951 952 name = kmalloc(PATH_MAX, GFP_NOFS); 953 if (!name) { 954 ret = -ENOMEM; 955 goto err; 956 } 957 ptr = name + PATH_MAX - 1; 958 ptr[0] = '\0'; 959 960 /* 961 * Walk up the subvolume trees in the tree of tree roots by root 962 * backrefs until we hit the top-level subvolume. 963 */ 964 while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) { 965 key.objectid = subvol_objectid; 966 key.type = BTRFS_ROOT_BACKREF_KEY; 967 key.offset = (u64)-1; 968 969 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 970 if (ret < 0) { 971 goto err; 972 } else if (ret > 0) { 973 ret = btrfs_previous_item(root, path, subvol_objectid, 974 BTRFS_ROOT_BACKREF_KEY); 975 if (ret < 0) { 976 goto err; 977 } else if (ret > 0) { 978 ret = -ENOENT; 979 goto err; 980 } 981 } 982 983 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 984 subvol_objectid = key.offset; 985 986 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], 987 struct btrfs_root_ref); 988 len = btrfs_root_ref_name_len(path->nodes[0], root_ref); 989 ptr -= len + 1; 990 if (ptr < name) { 991 ret = -ENAMETOOLONG; 992 goto err; 993 } 994 read_extent_buffer(path->nodes[0], ptr + 1, 995 (unsigned long)(root_ref + 1), len); 996 ptr[0] = '/'; 997 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref); 998 btrfs_release_path(path); 999 1000 key.objectid = subvol_objectid; 1001 key.type = BTRFS_ROOT_ITEM_KEY; 1002 key.offset = (u64)-1; 1003 fs_root = btrfs_read_fs_root_no_name(fs_info, &key); 1004 if (IS_ERR(fs_root)) { 1005 ret = PTR_ERR(fs_root); 1006 goto err; 1007 } 1008 1009 /* 1010 * Walk up the filesystem tree by inode refs until we hit the 1011 * root directory. 1012 */ 1013 while (dirid != BTRFS_FIRST_FREE_OBJECTID) { 1014 key.objectid = dirid; 1015 key.type = BTRFS_INODE_REF_KEY; 1016 key.offset = (u64)-1; 1017 1018 ret = btrfs_search_slot(NULL, fs_root, &key, path, 0, 0); 1019 if (ret < 0) { 1020 goto err; 1021 } else if (ret > 0) { 1022 ret = btrfs_previous_item(fs_root, path, dirid, 1023 BTRFS_INODE_REF_KEY); 1024 if (ret < 0) { 1025 goto err; 1026 } else if (ret > 0) { 1027 ret = -ENOENT; 1028 goto err; 1029 } 1030 } 1031 1032 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 1033 dirid = key.offset; 1034 1035 inode_ref = btrfs_item_ptr(path->nodes[0], 1036 path->slots[0], 1037 struct btrfs_inode_ref); 1038 len = btrfs_inode_ref_name_len(path->nodes[0], 1039 inode_ref); 1040 ptr -= len + 1; 1041 if (ptr < name) { 1042 ret = -ENAMETOOLONG; 1043 goto err; 1044 } 1045 read_extent_buffer(path->nodes[0], ptr + 1, 1046 (unsigned long)(inode_ref + 1), len); 1047 ptr[0] = '/'; 1048 btrfs_release_path(path); 1049 } 1050 } 1051 1052 btrfs_free_path(path); 1053 if (ptr == name + PATH_MAX - 1) { 1054 name[0] = '/'; 1055 name[1] = '\0'; 1056 } else { 1057 memmove(name, ptr, name + PATH_MAX - ptr); 1058 } 1059 return name; 1060 1061 err: 1062 btrfs_free_path(path); 1063 kfree(name); 1064 return ERR_PTR(ret); 1065 } 1066 1067 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid) 1068 { 1069 struct btrfs_root *root = fs_info->tree_root; 1070 struct btrfs_dir_item *di; 1071 struct btrfs_path *path; 1072 struct btrfs_key location; 1073 u64 dir_id; 1074 1075 path = btrfs_alloc_path(); 1076 if (!path) 1077 return -ENOMEM; 1078 path->leave_spinning = 1; 1079 1080 /* 1081 * Find the "default" dir item which points to the root item that we 1082 * will mount by default if we haven't been given a specific subvolume 1083 * to mount. 1084 */ 1085 dir_id = btrfs_super_root_dir(fs_info->super_copy); 1086 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 1087 if (IS_ERR(di)) { 1088 btrfs_free_path(path); 1089 return PTR_ERR(di); 1090 } 1091 if (!di) { 1092 /* 1093 * Ok the default dir item isn't there. This is weird since 1094 * it's always been there, but don't freak out, just try and 1095 * mount the top-level subvolume. 1096 */ 1097 btrfs_free_path(path); 1098 *objectid = BTRFS_FS_TREE_OBJECTID; 1099 return 0; 1100 } 1101 1102 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 1103 btrfs_free_path(path); 1104 *objectid = location.objectid; 1105 return 0; 1106 } 1107 1108 static int btrfs_fill_super(struct super_block *sb, 1109 struct btrfs_fs_devices *fs_devices, 1110 void *data) 1111 { 1112 struct inode *inode; 1113 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1114 struct btrfs_key key; 1115 int err; 1116 1117 sb->s_maxbytes = MAX_LFS_FILESIZE; 1118 sb->s_magic = BTRFS_SUPER_MAGIC; 1119 sb->s_op = &btrfs_super_ops; 1120 sb->s_d_op = &btrfs_dentry_operations; 1121 sb->s_export_op = &btrfs_export_ops; 1122 sb->s_xattr = btrfs_xattr_handlers; 1123 sb->s_time_gran = 1; 1124 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 1125 sb->s_flags |= MS_POSIXACL; 1126 #endif 1127 sb->s_flags |= MS_I_VERSION; 1128 sb->s_iflags |= SB_I_CGROUPWB; 1129 1130 err = super_setup_bdi(sb); 1131 if (err) { 1132 btrfs_err(fs_info, "super_setup_bdi failed"); 1133 return err; 1134 } 1135 1136 err = open_ctree(sb, fs_devices, (char *)data); 1137 if (err) { 1138 btrfs_err(fs_info, "open_ctree failed"); 1139 return err; 1140 } 1141 1142 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 1143 key.type = BTRFS_INODE_ITEM_KEY; 1144 key.offset = 0; 1145 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL); 1146 if (IS_ERR(inode)) { 1147 err = PTR_ERR(inode); 1148 goto fail_close; 1149 } 1150 1151 sb->s_root = d_make_root(inode); 1152 if (!sb->s_root) { 1153 err = -ENOMEM; 1154 goto fail_close; 1155 } 1156 1157 cleancache_init_fs(sb); 1158 sb->s_flags |= MS_ACTIVE; 1159 return 0; 1160 1161 fail_close: 1162 close_ctree(fs_info); 1163 return err; 1164 } 1165 1166 int btrfs_sync_fs(struct super_block *sb, int wait) 1167 { 1168 struct btrfs_trans_handle *trans; 1169 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1170 struct btrfs_root *root = fs_info->tree_root; 1171 1172 trace_btrfs_sync_fs(fs_info, wait); 1173 1174 if (!wait) { 1175 filemap_flush(fs_info->btree_inode->i_mapping); 1176 return 0; 1177 } 1178 1179 btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1); 1180 1181 trans = btrfs_attach_transaction_barrier(root); 1182 if (IS_ERR(trans)) { 1183 /* no transaction, don't bother */ 1184 if (PTR_ERR(trans) == -ENOENT) { 1185 /* 1186 * Exit unless we have some pending changes 1187 * that need to go through commit 1188 */ 1189 if (fs_info->pending_changes == 0) 1190 return 0; 1191 /* 1192 * A non-blocking test if the fs is frozen. We must not 1193 * start a new transaction here otherwise a deadlock 1194 * happens. The pending operations are delayed to the 1195 * next commit after thawing. 1196 */ 1197 if (__sb_start_write(sb, SB_FREEZE_WRITE, false)) 1198 __sb_end_write(sb, SB_FREEZE_WRITE); 1199 else 1200 return 0; 1201 trans = btrfs_start_transaction(root, 0); 1202 } 1203 if (IS_ERR(trans)) 1204 return PTR_ERR(trans); 1205 } 1206 return btrfs_commit_transaction(trans); 1207 } 1208 1209 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) 1210 { 1211 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); 1212 char *compress_type; 1213 1214 if (btrfs_test_opt(info, DEGRADED)) 1215 seq_puts(seq, ",degraded"); 1216 if (btrfs_test_opt(info, NODATASUM)) 1217 seq_puts(seq, ",nodatasum"); 1218 if (btrfs_test_opt(info, NODATACOW)) 1219 seq_puts(seq, ",nodatacow"); 1220 if (btrfs_test_opt(info, NOBARRIER)) 1221 seq_puts(seq, ",nobarrier"); 1222 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) 1223 seq_printf(seq, ",max_inline=%llu", info->max_inline); 1224 if (info->thread_pool_size != min_t(unsigned long, 1225 num_online_cpus() + 2, 8)) 1226 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 1227 if (btrfs_test_opt(info, COMPRESS)) { 1228 if (info->compress_type == BTRFS_COMPRESS_ZLIB) 1229 compress_type = "zlib"; 1230 else 1231 compress_type = "lzo"; 1232 if (btrfs_test_opt(info, FORCE_COMPRESS)) 1233 seq_printf(seq, ",compress-force=%s", compress_type); 1234 else 1235 seq_printf(seq, ",compress=%s", compress_type); 1236 } 1237 if (btrfs_test_opt(info, NOSSD)) 1238 seq_puts(seq, ",nossd"); 1239 if (btrfs_test_opt(info, SSD_SPREAD)) 1240 seq_puts(seq, ",ssd_spread"); 1241 else if (btrfs_test_opt(info, SSD)) 1242 seq_puts(seq, ",ssd"); 1243 if (btrfs_test_opt(info, NOTREELOG)) 1244 seq_puts(seq, ",notreelog"); 1245 if (btrfs_test_opt(info, NOLOGREPLAY)) 1246 seq_puts(seq, ",nologreplay"); 1247 if (btrfs_test_opt(info, FLUSHONCOMMIT)) 1248 seq_puts(seq, ",flushoncommit"); 1249 if (btrfs_test_opt(info, DISCARD)) 1250 seq_puts(seq, ",discard"); 1251 if (!(info->sb->s_flags & MS_POSIXACL)) 1252 seq_puts(seq, ",noacl"); 1253 if (btrfs_test_opt(info, SPACE_CACHE)) 1254 seq_puts(seq, ",space_cache"); 1255 else if (btrfs_test_opt(info, FREE_SPACE_TREE)) 1256 seq_puts(seq, ",space_cache=v2"); 1257 else 1258 seq_puts(seq, ",nospace_cache"); 1259 if (btrfs_test_opt(info, RESCAN_UUID_TREE)) 1260 seq_puts(seq, ",rescan_uuid_tree"); 1261 if (btrfs_test_opt(info, CLEAR_CACHE)) 1262 seq_puts(seq, ",clear_cache"); 1263 if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED)) 1264 seq_puts(seq, ",user_subvol_rm_allowed"); 1265 if (btrfs_test_opt(info, ENOSPC_DEBUG)) 1266 seq_puts(seq, ",enospc_debug"); 1267 if (btrfs_test_opt(info, AUTO_DEFRAG)) 1268 seq_puts(seq, ",autodefrag"); 1269 if (btrfs_test_opt(info, INODE_MAP_CACHE)) 1270 seq_puts(seq, ",inode_cache"); 1271 if (btrfs_test_opt(info, SKIP_BALANCE)) 1272 seq_puts(seq, ",skip_balance"); 1273 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 1274 if (btrfs_test_opt(info, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA)) 1275 seq_puts(seq, ",check_int_data"); 1276 else if (btrfs_test_opt(info, CHECK_INTEGRITY)) 1277 seq_puts(seq, ",check_int"); 1278 if (info->check_integrity_print_mask) 1279 seq_printf(seq, ",check_int_print_mask=%d", 1280 info->check_integrity_print_mask); 1281 #endif 1282 if (info->metadata_ratio) 1283 seq_printf(seq, ",metadata_ratio=%d", 1284 info->metadata_ratio); 1285 if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR)) 1286 seq_puts(seq, ",fatal_errors=panic"); 1287 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) 1288 seq_printf(seq, ",commit=%d", info->commit_interval); 1289 #ifdef CONFIG_BTRFS_DEBUG 1290 if (btrfs_test_opt(info, FRAGMENT_DATA)) 1291 seq_puts(seq, ",fragment=data"); 1292 if (btrfs_test_opt(info, FRAGMENT_METADATA)) 1293 seq_puts(seq, ",fragment=metadata"); 1294 #endif 1295 seq_printf(seq, ",subvolid=%llu", 1296 BTRFS_I(d_inode(dentry))->root->root_key.objectid); 1297 seq_puts(seq, ",subvol="); 1298 seq_dentry(seq, dentry, " \t\n\\"); 1299 return 0; 1300 } 1301 1302 static int btrfs_test_super(struct super_block *s, void *data) 1303 { 1304 struct btrfs_fs_info *p = data; 1305 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1306 1307 return fs_info->fs_devices == p->fs_devices; 1308 } 1309 1310 static int btrfs_set_super(struct super_block *s, void *data) 1311 { 1312 int err = set_anon_super(s, data); 1313 if (!err) 1314 s->s_fs_info = data; 1315 return err; 1316 } 1317 1318 /* 1319 * subvolumes are identified by ino 256 1320 */ 1321 static inline int is_subvolume_inode(struct inode *inode) 1322 { 1323 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 1324 return 1; 1325 return 0; 1326 } 1327 1328 /* 1329 * This will add subvolid=0 to the argument string while removing any subvol= 1330 * and subvolid= arguments to make sure we get the top-level root for path 1331 * walking to the subvol we want. 1332 */ 1333 static char *setup_root_args(char *args) 1334 { 1335 char *buf, *dst, *sep; 1336 1337 if (!args) 1338 return kstrdup("subvolid=0", GFP_NOFS); 1339 1340 /* The worst case is that we add ",subvolid=0" to the end. */ 1341 buf = dst = kmalloc(strlen(args) + strlen(",subvolid=0") + 1, GFP_NOFS); 1342 if (!buf) 1343 return NULL; 1344 1345 while (1) { 1346 sep = strchrnul(args, ','); 1347 if (!strstarts(args, "subvol=") && 1348 !strstarts(args, "subvolid=")) { 1349 memcpy(dst, args, sep - args); 1350 dst += sep - args; 1351 *dst++ = ','; 1352 } 1353 if (*sep) 1354 args = sep + 1; 1355 else 1356 break; 1357 } 1358 strcpy(dst, "subvolid=0"); 1359 1360 return buf; 1361 } 1362 1363 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid, 1364 int flags, const char *device_name, 1365 char *data) 1366 { 1367 struct dentry *root; 1368 struct vfsmount *mnt = NULL; 1369 char *newargs; 1370 int ret; 1371 1372 newargs = setup_root_args(data); 1373 if (!newargs) { 1374 root = ERR_PTR(-ENOMEM); 1375 goto out; 1376 } 1377 1378 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, newargs); 1379 if (PTR_ERR_OR_ZERO(mnt) == -EBUSY) { 1380 if (flags & MS_RDONLY) { 1381 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, 1382 device_name, newargs); 1383 } else { 1384 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, 1385 device_name, newargs); 1386 if (IS_ERR(mnt)) { 1387 root = ERR_CAST(mnt); 1388 mnt = NULL; 1389 goto out; 1390 } 1391 1392 down_write(&mnt->mnt_sb->s_umount); 1393 ret = btrfs_remount(mnt->mnt_sb, &flags, NULL); 1394 up_write(&mnt->mnt_sb->s_umount); 1395 if (ret < 0) { 1396 root = ERR_PTR(ret); 1397 goto out; 1398 } 1399 } 1400 } 1401 if (IS_ERR(mnt)) { 1402 root = ERR_CAST(mnt); 1403 mnt = NULL; 1404 goto out; 1405 } 1406 1407 if (!subvol_name) { 1408 if (!subvol_objectid) { 1409 ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb), 1410 &subvol_objectid); 1411 if (ret) { 1412 root = ERR_PTR(ret); 1413 goto out; 1414 } 1415 } 1416 subvol_name = get_subvol_name_from_objectid(btrfs_sb(mnt->mnt_sb), 1417 subvol_objectid); 1418 if (IS_ERR(subvol_name)) { 1419 root = ERR_CAST(subvol_name); 1420 subvol_name = NULL; 1421 goto out; 1422 } 1423 1424 } 1425 1426 root = mount_subtree(mnt, subvol_name); 1427 /* mount_subtree() drops our reference on the vfsmount. */ 1428 mnt = NULL; 1429 1430 if (!IS_ERR(root)) { 1431 struct super_block *s = root->d_sb; 1432 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1433 struct inode *root_inode = d_inode(root); 1434 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid; 1435 1436 ret = 0; 1437 if (!is_subvolume_inode(root_inode)) { 1438 btrfs_err(fs_info, "'%s' is not a valid subvolume", 1439 subvol_name); 1440 ret = -EINVAL; 1441 } 1442 if (subvol_objectid && root_objectid != subvol_objectid) { 1443 /* 1444 * This will also catch a race condition where a 1445 * subvolume which was passed by ID is renamed and 1446 * another subvolume is renamed over the old location. 1447 */ 1448 btrfs_err(fs_info, 1449 "subvol '%s' does not match subvolid %llu", 1450 subvol_name, subvol_objectid); 1451 ret = -EINVAL; 1452 } 1453 if (ret) { 1454 dput(root); 1455 root = ERR_PTR(ret); 1456 deactivate_locked_super(s); 1457 } 1458 } 1459 1460 out: 1461 mntput(mnt); 1462 kfree(newargs); 1463 kfree(subvol_name); 1464 return root; 1465 } 1466 1467 static int parse_security_options(char *orig_opts, 1468 struct security_mnt_opts *sec_opts) 1469 { 1470 char *secdata = NULL; 1471 int ret = 0; 1472 1473 secdata = alloc_secdata(); 1474 if (!secdata) 1475 return -ENOMEM; 1476 ret = security_sb_copy_data(orig_opts, secdata); 1477 if (ret) { 1478 free_secdata(secdata); 1479 return ret; 1480 } 1481 ret = security_sb_parse_opts_str(secdata, sec_opts); 1482 free_secdata(secdata); 1483 return ret; 1484 } 1485 1486 static int setup_security_options(struct btrfs_fs_info *fs_info, 1487 struct super_block *sb, 1488 struct security_mnt_opts *sec_opts) 1489 { 1490 int ret = 0; 1491 1492 /* 1493 * Call security_sb_set_mnt_opts() to check whether new sec_opts 1494 * is valid. 1495 */ 1496 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL); 1497 if (ret) 1498 return ret; 1499 1500 #ifdef CONFIG_SECURITY 1501 if (!fs_info->security_opts.num_mnt_opts) { 1502 /* first time security setup, copy sec_opts to fs_info */ 1503 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts)); 1504 } else { 1505 /* 1506 * Since SELinux (the only one supporting security_mnt_opts) 1507 * does NOT support changing context during remount/mount of 1508 * the same sb, this must be the same or part of the same 1509 * security options, just free it. 1510 */ 1511 security_free_mnt_opts(sec_opts); 1512 } 1513 #endif 1514 return ret; 1515 } 1516 1517 /* 1518 * Find a superblock for the given device / mount point. 1519 * 1520 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 1521 * for multiple device setup. Make sure to keep it in sync. 1522 */ 1523 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 1524 const char *device_name, void *data) 1525 { 1526 struct block_device *bdev = NULL; 1527 struct super_block *s; 1528 struct btrfs_fs_devices *fs_devices = NULL; 1529 struct btrfs_fs_info *fs_info = NULL; 1530 struct security_mnt_opts new_sec_opts; 1531 fmode_t mode = FMODE_READ; 1532 char *subvol_name = NULL; 1533 u64 subvol_objectid = 0; 1534 int error = 0; 1535 1536 if (!(flags & MS_RDONLY)) 1537 mode |= FMODE_WRITE; 1538 1539 error = btrfs_parse_early_options(data, mode, fs_type, 1540 &subvol_name, &subvol_objectid, 1541 &fs_devices); 1542 if (error) { 1543 kfree(subvol_name); 1544 return ERR_PTR(error); 1545 } 1546 1547 if (subvol_name || subvol_objectid != BTRFS_FS_TREE_OBJECTID) { 1548 /* mount_subvol() will free subvol_name. */ 1549 return mount_subvol(subvol_name, subvol_objectid, flags, 1550 device_name, data); 1551 } 1552 1553 security_init_mnt_opts(&new_sec_opts); 1554 if (data) { 1555 error = parse_security_options(data, &new_sec_opts); 1556 if (error) 1557 return ERR_PTR(error); 1558 } 1559 1560 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); 1561 if (error) 1562 goto error_sec_opts; 1563 1564 /* 1565 * Setup a dummy root and fs_info for test/set super. This is because 1566 * we don't actually fill this stuff out until open_ctree, but we need 1567 * it for searching for existing supers, so this lets us do that and 1568 * then open_ctree will properly initialize everything later. 1569 */ 1570 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); 1571 if (!fs_info) { 1572 error = -ENOMEM; 1573 goto error_sec_opts; 1574 } 1575 1576 fs_info->fs_devices = fs_devices; 1577 1578 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1579 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1580 security_init_mnt_opts(&fs_info->security_opts); 1581 if (!fs_info->super_copy || !fs_info->super_for_commit) { 1582 error = -ENOMEM; 1583 goto error_fs_info; 1584 } 1585 1586 error = btrfs_open_devices(fs_devices, mode, fs_type); 1587 if (error) 1588 goto error_fs_info; 1589 1590 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 1591 error = -EACCES; 1592 goto error_close_devices; 1593 } 1594 1595 bdev = fs_devices->latest_bdev; 1596 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC, 1597 fs_info); 1598 if (IS_ERR(s)) { 1599 error = PTR_ERR(s); 1600 goto error_close_devices; 1601 } 1602 1603 if (s->s_root) { 1604 btrfs_close_devices(fs_devices); 1605 free_fs_info(fs_info); 1606 if ((flags ^ s->s_flags) & MS_RDONLY) 1607 error = -EBUSY; 1608 } else { 1609 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev); 1610 btrfs_sb(s)->bdev_holder = fs_type; 1611 error = btrfs_fill_super(s, fs_devices, data); 1612 } 1613 if (error) { 1614 deactivate_locked_super(s); 1615 goto error_sec_opts; 1616 } 1617 1618 fs_info = btrfs_sb(s); 1619 error = setup_security_options(fs_info, s, &new_sec_opts); 1620 if (error) { 1621 deactivate_locked_super(s); 1622 goto error_sec_opts; 1623 } 1624 1625 return dget(s->s_root); 1626 1627 error_close_devices: 1628 btrfs_close_devices(fs_devices); 1629 error_fs_info: 1630 free_fs_info(fs_info); 1631 error_sec_opts: 1632 security_free_mnt_opts(&new_sec_opts); 1633 return ERR_PTR(error); 1634 } 1635 1636 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, 1637 int new_pool_size, int old_pool_size) 1638 { 1639 if (new_pool_size == old_pool_size) 1640 return; 1641 1642 fs_info->thread_pool_size = new_pool_size; 1643 1644 btrfs_info(fs_info, "resize thread pool %d -> %d", 1645 old_pool_size, new_pool_size); 1646 1647 btrfs_workqueue_set_max(fs_info->workers, new_pool_size); 1648 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size); 1649 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size); 1650 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size); 1651 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size); 1652 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size); 1653 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers, 1654 new_pool_size); 1655 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size); 1656 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size); 1657 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size); 1658 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size); 1659 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers, 1660 new_pool_size); 1661 } 1662 1663 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info) 1664 { 1665 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1666 } 1667 1668 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info, 1669 unsigned long old_opts, int flags) 1670 { 1671 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1672 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1673 (flags & MS_RDONLY))) { 1674 /* wait for any defraggers to finish */ 1675 wait_event(fs_info->transaction_wait, 1676 (atomic_read(&fs_info->defrag_running) == 0)); 1677 if (flags & MS_RDONLY) 1678 sync_filesystem(fs_info->sb); 1679 } 1680 } 1681 1682 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info, 1683 unsigned long old_opts) 1684 { 1685 /* 1686 * We need to cleanup all defragable inodes if the autodefragment is 1687 * close or the filesystem is read only. 1688 */ 1689 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1690 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1691 (fs_info->sb->s_flags & MS_RDONLY))) { 1692 btrfs_cleanup_defrag_inodes(fs_info); 1693 } 1694 1695 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1696 } 1697 1698 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1699 { 1700 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1701 struct btrfs_root *root = fs_info->tree_root; 1702 unsigned old_flags = sb->s_flags; 1703 unsigned long old_opts = fs_info->mount_opt; 1704 unsigned long old_compress_type = fs_info->compress_type; 1705 u64 old_max_inline = fs_info->max_inline; 1706 int old_thread_pool_size = fs_info->thread_pool_size; 1707 unsigned int old_metadata_ratio = fs_info->metadata_ratio; 1708 int ret; 1709 1710 sync_filesystem(sb); 1711 btrfs_remount_prepare(fs_info); 1712 1713 if (data) { 1714 struct security_mnt_opts new_sec_opts; 1715 1716 security_init_mnt_opts(&new_sec_opts); 1717 ret = parse_security_options(data, &new_sec_opts); 1718 if (ret) 1719 goto restore; 1720 ret = setup_security_options(fs_info, sb, 1721 &new_sec_opts); 1722 if (ret) { 1723 security_free_mnt_opts(&new_sec_opts); 1724 goto restore; 1725 } 1726 } 1727 1728 ret = btrfs_parse_options(fs_info, data, *flags); 1729 if (ret) { 1730 ret = -EINVAL; 1731 goto restore; 1732 } 1733 1734 btrfs_remount_begin(fs_info, old_opts, *flags); 1735 btrfs_resize_thread_pool(fs_info, 1736 fs_info->thread_pool_size, old_thread_pool_size); 1737 1738 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1739 goto out; 1740 1741 if (*flags & MS_RDONLY) { 1742 /* 1743 * this also happens on 'umount -rf' or on shutdown, when 1744 * the filesystem is busy. 1745 */ 1746 cancel_work_sync(&fs_info->async_reclaim_work); 1747 1748 /* wait for the uuid_scan task to finish */ 1749 down(&fs_info->uuid_tree_rescan_sem); 1750 /* avoid complains from lockdep et al. */ 1751 up(&fs_info->uuid_tree_rescan_sem); 1752 1753 sb->s_flags |= MS_RDONLY; 1754 1755 /* 1756 * Setting MS_RDONLY will put the cleaner thread to 1757 * sleep at the next loop if it's already active. 1758 * If it's already asleep, we'll leave unused block 1759 * groups on disk until we're mounted read-write again 1760 * unless we clean them up here. 1761 */ 1762 btrfs_delete_unused_bgs(fs_info); 1763 1764 btrfs_dev_replace_suspend_for_unmount(fs_info); 1765 btrfs_scrub_cancel(fs_info); 1766 btrfs_pause_balance(fs_info); 1767 1768 ret = btrfs_commit_super(fs_info); 1769 if (ret) 1770 goto restore; 1771 } else { 1772 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { 1773 btrfs_err(fs_info, 1774 "Remounting read-write after error is not allowed"); 1775 ret = -EINVAL; 1776 goto restore; 1777 } 1778 if (fs_info->fs_devices->rw_devices == 0) { 1779 ret = -EACCES; 1780 goto restore; 1781 } 1782 1783 if (fs_info->fs_devices->missing_devices > 1784 fs_info->num_tolerated_disk_barrier_failures) { 1785 btrfs_warn(fs_info, 1786 "too many missing devices, writeable remount is not allowed"); 1787 ret = -EACCES; 1788 goto restore; 1789 } 1790 1791 if (btrfs_super_log_root(fs_info->super_copy) != 0) { 1792 ret = -EINVAL; 1793 goto restore; 1794 } 1795 1796 ret = btrfs_cleanup_fs_roots(fs_info); 1797 if (ret) 1798 goto restore; 1799 1800 /* recover relocation */ 1801 mutex_lock(&fs_info->cleaner_mutex); 1802 ret = btrfs_recover_relocation(root); 1803 mutex_unlock(&fs_info->cleaner_mutex); 1804 if (ret) 1805 goto restore; 1806 1807 ret = btrfs_resume_balance_async(fs_info); 1808 if (ret) 1809 goto restore; 1810 1811 ret = btrfs_resume_dev_replace_async(fs_info); 1812 if (ret) { 1813 btrfs_warn(fs_info, "failed to resume dev_replace"); 1814 goto restore; 1815 } 1816 1817 if (!fs_info->uuid_root) { 1818 btrfs_info(fs_info, "creating UUID tree"); 1819 ret = btrfs_create_uuid_tree(fs_info); 1820 if (ret) { 1821 btrfs_warn(fs_info, 1822 "failed to create the UUID tree %d", 1823 ret); 1824 goto restore; 1825 } 1826 } 1827 sb->s_flags &= ~MS_RDONLY; 1828 1829 set_bit(BTRFS_FS_OPEN, &fs_info->flags); 1830 } 1831 out: 1832 wake_up_process(fs_info->transaction_kthread); 1833 btrfs_remount_cleanup(fs_info, old_opts); 1834 return 0; 1835 1836 restore: 1837 /* We've hit an error - don't reset MS_RDONLY */ 1838 if (sb->s_flags & MS_RDONLY) 1839 old_flags |= MS_RDONLY; 1840 sb->s_flags = old_flags; 1841 fs_info->mount_opt = old_opts; 1842 fs_info->compress_type = old_compress_type; 1843 fs_info->max_inline = old_max_inline; 1844 btrfs_resize_thread_pool(fs_info, 1845 old_thread_pool_size, fs_info->thread_pool_size); 1846 fs_info->metadata_ratio = old_metadata_ratio; 1847 btrfs_remount_cleanup(fs_info, old_opts); 1848 return ret; 1849 } 1850 1851 /* Used to sort the devices by max_avail(descending sort) */ 1852 static int btrfs_cmp_device_free_bytes(const void *dev_info1, 1853 const void *dev_info2) 1854 { 1855 if (((struct btrfs_device_info *)dev_info1)->max_avail > 1856 ((struct btrfs_device_info *)dev_info2)->max_avail) 1857 return -1; 1858 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 1859 ((struct btrfs_device_info *)dev_info2)->max_avail) 1860 return 1; 1861 else 1862 return 0; 1863 } 1864 1865 /* 1866 * sort the devices by max_avail, in which max free extent size of each device 1867 * is stored.(Descending Sort) 1868 */ 1869 static inline void btrfs_descending_sort_devices( 1870 struct btrfs_device_info *devices, 1871 size_t nr_devices) 1872 { 1873 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1874 btrfs_cmp_device_free_bytes, NULL); 1875 } 1876 1877 /* 1878 * The helper to calc the free space on the devices that can be used to store 1879 * file data. 1880 */ 1881 static int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info, 1882 u64 *free_bytes) 1883 { 1884 struct btrfs_device_info *devices_info; 1885 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1886 struct btrfs_device *device; 1887 u64 skip_space; 1888 u64 type; 1889 u64 avail_space; 1890 u64 min_stripe_size; 1891 int min_stripes = 1, num_stripes = 1; 1892 int i = 0, nr_devices; 1893 1894 /* 1895 * We aren't under the device list lock, so this is racy-ish, but good 1896 * enough for our purposes. 1897 */ 1898 nr_devices = fs_info->fs_devices->open_devices; 1899 if (!nr_devices) { 1900 smp_mb(); 1901 nr_devices = fs_info->fs_devices->open_devices; 1902 ASSERT(nr_devices); 1903 if (!nr_devices) { 1904 *free_bytes = 0; 1905 return 0; 1906 } 1907 } 1908 1909 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info), 1910 GFP_KERNEL); 1911 if (!devices_info) 1912 return -ENOMEM; 1913 1914 /* calc min stripe number for data space allocation */ 1915 type = btrfs_data_alloc_profile(fs_info); 1916 if (type & BTRFS_BLOCK_GROUP_RAID0) { 1917 min_stripes = 2; 1918 num_stripes = nr_devices; 1919 } else if (type & BTRFS_BLOCK_GROUP_RAID1) { 1920 min_stripes = 2; 1921 num_stripes = 2; 1922 } else if (type & BTRFS_BLOCK_GROUP_RAID10) { 1923 min_stripes = 4; 1924 num_stripes = 4; 1925 } 1926 1927 if (type & BTRFS_BLOCK_GROUP_DUP) 1928 min_stripe_size = 2 * BTRFS_STRIPE_LEN; 1929 else 1930 min_stripe_size = BTRFS_STRIPE_LEN; 1931 1932 rcu_read_lock(); 1933 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { 1934 if (!device->in_fs_metadata || !device->bdev || 1935 device->is_tgtdev_for_dev_replace) 1936 continue; 1937 1938 if (i >= nr_devices) 1939 break; 1940 1941 avail_space = device->total_bytes - device->bytes_used; 1942 1943 /* align with stripe_len */ 1944 avail_space = div_u64(avail_space, BTRFS_STRIPE_LEN); 1945 avail_space *= BTRFS_STRIPE_LEN; 1946 1947 /* 1948 * In order to avoid overwriting the superblock on the drive, 1949 * btrfs starts at an offset of at least 1MB when doing chunk 1950 * allocation. 1951 */ 1952 skip_space = SZ_1M; 1953 1954 /* 1955 * we can use the free space in [0, skip_space - 1], subtract 1956 * it from the total. 1957 */ 1958 if (avail_space && avail_space >= skip_space) 1959 avail_space -= skip_space; 1960 else 1961 avail_space = 0; 1962 1963 if (avail_space < min_stripe_size) 1964 continue; 1965 1966 devices_info[i].dev = device; 1967 devices_info[i].max_avail = avail_space; 1968 1969 i++; 1970 } 1971 rcu_read_unlock(); 1972 1973 nr_devices = i; 1974 1975 btrfs_descending_sort_devices(devices_info, nr_devices); 1976 1977 i = nr_devices - 1; 1978 avail_space = 0; 1979 while (nr_devices >= min_stripes) { 1980 if (num_stripes > nr_devices) 1981 num_stripes = nr_devices; 1982 1983 if (devices_info[i].max_avail >= min_stripe_size) { 1984 int j; 1985 u64 alloc_size; 1986 1987 avail_space += devices_info[i].max_avail * num_stripes; 1988 alloc_size = devices_info[i].max_avail; 1989 for (j = i + 1 - num_stripes; j <= i; j++) 1990 devices_info[j].max_avail -= alloc_size; 1991 } 1992 i--; 1993 nr_devices--; 1994 } 1995 1996 kfree(devices_info); 1997 *free_bytes = avail_space; 1998 return 0; 1999 } 2000 2001 /* 2002 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles. 2003 * 2004 * If there's a redundant raid level at DATA block groups, use the respective 2005 * multiplier to scale the sizes. 2006 * 2007 * Unused device space usage is based on simulating the chunk allocator 2008 * algorithm that respects the device sizes and order of allocations. This is 2009 * a close approximation of the actual use but there are other factors that may 2010 * change the result (like a new metadata chunk). 2011 * 2012 * If metadata is exhausted, f_bavail will be 0. 2013 */ 2014 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 2015 { 2016 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); 2017 struct btrfs_super_block *disk_super = fs_info->super_copy; 2018 struct list_head *head = &fs_info->space_info; 2019 struct btrfs_space_info *found; 2020 u64 total_used = 0; 2021 u64 total_free_data = 0; 2022 u64 total_free_meta = 0; 2023 int bits = dentry->d_sb->s_blocksize_bits; 2024 __be32 *fsid = (__be32 *)fs_info->fsid; 2025 unsigned factor = 1; 2026 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 2027 int ret; 2028 u64 thresh = 0; 2029 int mixed = 0; 2030 2031 rcu_read_lock(); 2032 list_for_each_entry_rcu(found, head, list) { 2033 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 2034 int i; 2035 2036 total_free_data += found->disk_total - found->disk_used; 2037 total_free_data -= 2038 btrfs_account_ro_block_groups_free_space(found); 2039 2040 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { 2041 if (!list_empty(&found->block_groups[i])) { 2042 switch (i) { 2043 case BTRFS_RAID_DUP: 2044 case BTRFS_RAID_RAID1: 2045 case BTRFS_RAID_RAID10: 2046 factor = 2; 2047 } 2048 } 2049 } 2050 } 2051 2052 /* 2053 * Metadata in mixed block goup profiles are accounted in data 2054 */ 2055 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) { 2056 if (found->flags & BTRFS_BLOCK_GROUP_DATA) 2057 mixed = 1; 2058 else 2059 total_free_meta += found->disk_total - 2060 found->disk_used; 2061 } 2062 2063 total_used += found->disk_used; 2064 } 2065 2066 rcu_read_unlock(); 2067 2068 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor); 2069 buf->f_blocks >>= bits; 2070 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits); 2071 2072 /* Account global block reserve as used, it's in logical size already */ 2073 spin_lock(&block_rsv->lock); 2074 /* Mixed block groups accounting is not byte-accurate, avoid overflow */ 2075 if (buf->f_bfree >= block_rsv->size >> bits) 2076 buf->f_bfree -= block_rsv->size >> bits; 2077 else 2078 buf->f_bfree = 0; 2079 spin_unlock(&block_rsv->lock); 2080 2081 buf->f_bavail = div_u64(total_free_data, factor); 2082 ret = btrfs_calc_avail_data_space(fs_info, &total_free_data); 2083 if (ret) 2084 return ret; 2085 buf->f_bavail += div_u64(total_free_data, factor); 2086 buf->f_bavail = buf->f_bavail >> bits; 2087 2088 /* 2089 * We calculate the remaining metadata space minus global reserve. If 2090 * this is (supposedly) smaller than zero, there's no space. But this 2091 * does not hold in practice, the exhausted state happens where's still 2092 * some positive delta. So we apply some guesswork and compare the 2093 * delta to a 4M threshold. (Practically observed delta was ~2M.) 2094 * 2095 * We probably cannot calculate the exact threshold value because this 2096 * depends on the internal reservations requested by various 2097 * operations, so some operations that consume a few metadata will 2098 * succeed even if the Avail is zero. But this is better than the other 2099 * way around. 2100 */ 2101 thresh = 4 * 1024 * 1024; 2102 2103 if (!mixed && total_free_meta - thresh < block_rsv->size) 2104 buf->f_bavail = 0; 2105 2106 buf->f_type = BTRFS_SUPER_MAGIC; 2107 buf->f_bsize = dentry->d_sb->s_blocksize; 2108 buf->f_namelen = BTRFS_NAME_LEN; 2109 2110 /* We treat it as constant endianness (it doesn't matter _which_) 2111 because we want the fsid to come out the same whether mounted 2112 on a big-endian or little-endian host */ 2113 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 2114 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 2115 /* Mask in the root object ID too, to disambiguate subvols */ 2116 buf->f_fsid.val[0] ^= BTRFS_I(d_inode(dentry))->root->objectid >> 32; 2117 buf->f_fsid.val[1] ^= BTRFS_I(d_inode(dentry))->root->objectid; 2118 2119 return 0; 2120 } 2121 2122 static void btrfs_kill_super(struct super_block *sb) 2123 { 2124 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2125 kill_anon_super(sb); 2126 free_fs_info(fs_info); 2127 } 2128 2129 static struct file_system_type btrfs_fs_type = { 2130 .owner = THIS_MODULE, 2131 .name = "btrfs", 2132 .mount = btrfs_mount, 2133 .kill_sb = btrfs_kill_super, 2134 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, 2135 }; 2136 MODULE_ALIAS_FS("btrfs"); 2137 2138 static int btrfs_control_open(struct inode *inode, struct file *file) 2139 { 2140 /* 2141 * The control file's private_data is used to hold the 2142 * transaction when it is started and is used to keep 2143 * track of whether a transaction is already in progress. 2144 */ 2145 file->private_data = NULL; 2146 return 0; 2147 } 2148 2149 /* 2150 * used by btrfsctl to scan devices when no FS is mounted 2151 */ 2152 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 2153 unsigned long arg) 2154 { 2155 struct btrfs_ioctl_vol_args *vol; 2156 struct btrfs_fs_devices *fs_devices; 2157 int ret = -ENOTTY; 2158 2159 if (!capable(CAP_SYS_ADMIN)) 2160 return -EPERM; 2161 2162 vol = memdup_user((void __user *)arg, sizeof(*vol)); 2163 if (IS_ERR(vol)) 2164 return PTR_ERR(vol); 2165 2166 switch (cmd) { 2167 case BTRFS_IOC_SCAN_DEV: 2168 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 2169 &btrfs_fs_type, &fs_devices); 2170 break; 2171 case BTRFS_IOC_DEVICES_READY: 2172 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 2173 &btrfs_fs_type, &fs_devices); 2174 if (ret) 2175 break; 2176 ret = !(fs_devices->num_devices == fs_devices->total_devices); 2177 break; 2178 case BTRFS_IOC_GET_SUPPORTED_FEATURES: 2179 ret = btrfs_ioctl_get_supported_features((void __user*)arg); 2180 break; 2181 } 2182 2183 kfree(vol); 2184 return ret; 2185 } 2186 2187 static int btrfs_freeze(struct super_block *sb) 2188 { 2189 struct btrfs_trans_handle *trans; 2190 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2191 struct btrfs_root *root = fs_info->tree_root; 2192 2193 set_bit(BTRFS_FS_FROZEN, &fs_info->flags); 2194 /* 2195 * We don't need a barrier here, we'll wait for any transaction that 2196 * could be in progress on other threads (and do delayed iputs that 2197 * we want to avoid on a frozen filesystem), or do the commit 2198 * ourselves. 2199 */ 2200 trans = btrfs_attach_transaction_barrier(root); 2201 if (IS_ERR(trans)) { 2202 /* no transaction, don't bother */ 2203 if (PTR_ERR(trans) == -ENOENT) 2204 return 0; 2205 return PTR_ERR(trans); 2206 } 2207 return btrfs_commit_transaction(trans); 2208 } 2209 2210 static int btrfs_unfreeze(struct super_block *sb) 2211 { 2212 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 2213 2214 clear_bit(BTRFS_FS_FROZEN, &fs_info->flags); 2215 return 0; 2216 } 2217 2218 static int btrfs_show_devname(struct seq_file *m, struct dentry *root) 2219 { 2220 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); 2221 struct btrfs_fs_devices *cur_devices; 2222 struct btrfs_device *dev, *first_dev = NULL; 2223 struct list_head *head; 2224 struct rcu_string *name; 2225 2226 mutex_lock(&fs_info->fs_devices->device_list_mutex); 2227 cur_devices = fs_info->fs_devices; 2228 while (cur_devices) { 2229 head = &cur_devices->devices; 2230 list_for_each_entry(dev, head, dev_list) { 2231 if (dev->missing) 2232 continue; 2233 if (!dev->name) 2234 continue; 2235 if (!first_dev || dev->devid < first_dev->devid) 2236 first_dev = dev; 2237 } 2238 cur_devices = cur_devices->seed; 2239 } 2240 2241 if (first_dev) { 2242 rcu_read_lock(); 2243 name = rcu_dereference(first_dev->name); 2244 seq_escape(m, name->str, " \t\n\\"); 2245 rcu_read_unlock(); 2246 } else { 2247 WARN_ON(1); 2248 } 2249 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 2250 return 0; 2251 } 2252 2253 static const struct super_operations btrfs_super_ops = { 2254 .drop_inode = btrfs_drop_inode, 2255 .evict_inode = btrfs_evict_inode, 2256 .put_super = btrfs_put_super, 2257 .sync_fs = btrfs_sync_fs, 2258 .show_options = btrfs_show_options, 2259 .show_devname = btrfs_show_devname, 2260 .write_inode = btrfs_write_inode, 2261 .alloc_inode = btrfs_alloc_inode, 2262 .destroy_inode = btrfs_destroy_inode, 2263 .statfs = btrfs_statfs, 2264 .remount_fs = btrfs_remount, 2265 .freeze_fs = btrfs_freeze, 2266 .unfreeze_fs = btrfs_unfreeze, 2267 }; 2268 2269 static const struct file_operations btrfs_ctl_fops = { 2270 .open = btrfs_control_open, 2271 .unlocked_ioctl = btrfs_control_ioctl, 2272 .compat_ioctl = btrfs_control_ioctl, 2273 .owner = THIS_MODULE, 2274 .llseek = noop_llseek, 2275 }; 2276 2277 static struct miscdevice btrfs_misc = { 2278 .minor = BTRFS_MINOR, 2279 .name = "btrfs-control", 2280 .fops = &btrfs_ctl_fops 2281 }; 2282 2283 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 2284 MODULE_ALIAS("devname:btrfs-control"); 2285 2286 static int btrfs_interface_init(void) 2287 { 2288 return misc_register(&btrfs_misc); 2289 } 2290 2291 static void btrfs_interface_exit(void) 2292 { 2293 misc_deregister(&btrfs_misc); 2294 } 2295 2296 static void btrfs_print_mod_info(void) 2297 { 2298 pr_info("Btrfs loaded, crc32c=%s" 2299 #ifdef CONFIG_BTRFS_DEBUG 2300 ", debug=on" 2301 #endif 2302 #ifdef CONFIG_BTRFS_ASSERT 2303 ", assert=on" 2304 #endif 2305 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 2306 ", integrity-checker=on" 2307 #endif 2308 "\n", 2309 btrfs_crc32c_impl()); 2310 } 2311 2312 static int __init init_btrfs_fs(void) 2313 { 2314 int err; 2315 2316 err = btrfs_hash_init(); 2317 if (err) 2318 return err; 2319 2320 btrfs_props_init(); 2321 2322 err = btrfs_init_sysfs(); 2323 if (err) 2324 goto free_hash; 2325 2326 btrfs_init_compress(); 2327 2328 err = btrfs_init_cachep(); 2329 if (err) 2330 goto free_compress; 2331 2332 err = extent_io_init(); 2333 if (err) 2334 goto free_cachep; 2335 2336 err = extent_map_init(); 2337 if (err) 2338 goto free_extent_io; 2339 2340 err = ordered_data_init(); 2341 if (err) 2342 goto free_extent_map; 2343 2344 err = btrfs_delayed_inode_init(); 2345 if (err) 2346 goto free_ordered_data; 2347 2348 err = btrfs_auto_defrag_init(); 2349 if (err) 2350 goto free_delayed_inode; 2351 2352 err = btrfs_delayed_ref_init(); 2353 if (err) 2354 goto free_auto_defrag; 2355 2356 err = btrfs_prelim_ref_init(); 2357 if (err) 2358 goto free_delayed_ref; 2359 2360 err = btrfs_end_io_wq_init(); 2361 if (err) 2362 goto free_prelim_ref; 2363 2364 err = btrfs_interface_init(); 2365 if (err) 2366 goto free_end_io_wq; 2367 2368 btrfs_init_lockdep(); 2369 2370 btrfs_print_mod_info(); 2371 2372 err = btrfs_run_sanity_tests(); 2373 if (err) 2374 goto unregister_ioctl; 2375 2376 err = register_filesystem(&btrfs_fs_type); 2377 if (err) 2378 goto unregister_ioctl; 2379 2380 return 0; 2381 2382 unregister_ioctl: 2383 btrfs_interface_exit(); 2384 free_end_io_wq: 2385 btrfs_end_io_wq_exit(); 2386 free_prelim_ref: 2387 btrfs_prelim_ref_exit(); 2388 free_delayed_ref: 2389 btrfs_delayed_ref_exit(); 2390 free_auto_defrag: 2391 btrfs_auto_defrag_exit(); 2392 free_delayed_inode: 2393 btrfs_delayed_inode_exit(); 2394 free_ordered_data: 2395 ordered_data_exit(); 2396 free_extent_map: 2397 extent_map_exit(); 2398 free_extent_io: 2399 extent_io_exit(); 2400 free_cachep: 2401 btrfs_destroy_cachep(); 2402 free_compress: 2403 btrfs_exit_compress(); 2404 btrfs_exit_sysfs(); 2405 free_hash: 2406 btrfs_hash_exit(); 2407 return err; 2408 } 2409 2410 static void __exit exit_btrfs_fs(void) 2411 { 2412 btrfs_destroy_cachep(); 2413 btrfs_delayed_ref_exit(); 2414 btrfs_auto_defrag_exit(); 2415 btrfs_delayed_inode_exit(); 2416 btrfs_prelim_ref_exit(); 2417 ordered_data_exit(); 2418 extent_map_exit(); 2419 extent_io_exit(); 2420 btrfs_interface_exit(); 2421 btrfs_end_io_wq_exit(); 2422 unregister_filesystem(&btrfs_fs_type); 2423 btrfs_exit_sysfs(); 2424 btrfs_cleanup_fs_uuids(); 2425 btrfs_exit_compress(); 2426 btrfs_hash_exit(); 2427 } 2428 2429 late_initcall(init_btrfs_fs); 2430 module_exit(exit_btrfs_fs) 2431 2432 MODULE_LICENSE("GPL"); 2433