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 static const char *btrfs_decode_error(int errno) 73 { 74 char *errstr = "unknown"; 75 76 switch (errno) { 77 case -EIO: 78 errstr = "IO failure"; 79 break; 80 case -ENOMEM: 81 errstr = "Out of memory"; 82 break; 83 case -EROFS: 84 errstr = "Readonly filesystem"; 85 break; 86 case -EEXIST: 87 errstr = "Object already exists"; 88 break; 89 case -ENOSPC: 90 errstr = "No space left"; 91 break; 92 case -ENOENT: 93 errstr = "No such entry"; 94 break; 95 } 96 97 return errstr; 98 } 99 100 static void save_error_info(struct btrfs_fs_info *fs_info) 101 { 102 /* 103 * today we only save the error info into ram. Long term we'll 104 * also send it down to the disk 105 */ 106 set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state); 107 } 108 109 /* btrfs handle error by forcing the filesystem readonly */ 110 static void btrfs_handle_error(struct btrfs_fs_info *fs_info) 111 { 112 struct super_block *sb = fs_info->sb; 113 114 if (sb->s_flags & MS_RDONLY) 115 return; 116 117 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) { 118 sb->s_flags |= MS_RDONLY; 119 btrfs_info(fs_info, "forced readonly"); 120 /* 121 * Note that a running device replace operation is not 122 * canceled here although there is no way to update 123 * the progress. It would add the risk of a deadlock, 124 * therefore the canceling is ommited. The only penalty 125 * is that some I/O remains active until the procedure 126 * completes. The next time when the filesystem is 127 * mounted writeable again, the device replace 128 * operation continues. 129 */ 130 } 131 } 132 133 #ifdef CONFIG_PRINTK 134 /* 135 * __btrfs_std_error decodes expected errors from the caller and 136 * invokes the approciate error response. 137 */ 138 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, 139 unsigned int line, int errno, const char *fmt, ...) 140 { 141 struct super_block *sb = fs_info->sb; 142 const char *errstr; 143 144 /* 145 * Special case: if the error is EROFS, and we're already 146 * under MS_RDONLY, then it is safe here. 147 */ 148 if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) 149 return; 150 151 errstr = btrfs_decode_error(errno); 152 if (fmt) { 153 struct va_format vaf; 154 va_list args; 155 156 va_start(args, fmt); 157 vaf.fmt = fmt; 158 vaf.va = &args; 159 160 printk(KERN_CRIT 161 "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n", 162 sb->s_id, function, line, errno, errstr, &vaf); 163 va_end(args); 164 } else { 165 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n", 166 sb->s_id, function, line, errno, errstr); 167 } 168 169 /* Don't go through full error handling during mount */ 170 save_error_info(fs_info); 171 if (sb->s_flags & MS_BORN) 172 btrfs_handle_error(fs_info); 173 } 174 175 static const char * const logtypes[] = { 176 "emergency", 177 "alert", 178 "critical", 179 "error", 180 "warning", 181 "notice", 182 "info", 183 "debug", 184 }; 185 186 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...) 187 { 188 struct super_block *sb = fs_info->sb; 189 char lvl[4]; 190 struct va_format vaf; 191 va_list args; 192 const char *type = logtypes[4]; 193 int kern_level; 194 195 va_start(args, fmt); 196 197 kern_level = printk_get_level(fmt); 198 if (kern_level) { 199 size_t size = printk_skip_level(fmt) - fmt; 200 memcpy(lvl, fmt, size); 201 lvl[size] = '\0'; 202 fmt += size; 203 type = logtypes[kern_level - '0']; 204 } else 205 *lvl = '\0'; 206 207 vaf.fmt = fmt; 208 vaf.va = &args; 209 210 printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf); 211 212 va_end(args); 213 } 214 215 #else 216 217 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, 218 unsigned int line, int errno, const char *fmt, ...) 219 { 220 struct super_block *sb = fs_info->sb; 221 222 /* 223 * Special case: if the error is EROFS, and we're already 224 * under MS_RDONLY, then it is safe here. 225 */ 226 if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) 227 return; 228 229 /* Don't go through full error handling during mount */ 230 if (sb->s_flags & MS_BORN) { 231 save_error_info(fs_info); 232 btrfs_handle_error(fs_info); 233 } 234 } 235 #endif 236 237 /* 238 * We only mark the transaction aborted and then set the file system read-only. 239 * This will prevent new transactions from starting or trying to join this 240 * one. 241 * 242 * This means that error recovery at the call site is limited to freeing 243 * any local memory allocations and passing the error code up without 244 * further cleanup. The transaction should complete as it normally would 245 * in the call path but will return -EIO. 246 * 247 * We'll complete the cleanup in btrfs_end_transaction and 248 * btrfs_commit_transaction. 249 */ 250 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 251 struct btrfs_root *root, const char *function, 252 unsigned int line, int errno) 253 { 254 /* 255 * Report first abort since mount 256 */ 257 if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED, 258 &root->fs_info->fs_state)) { 259 WARN(1, KERN_DEBUG "BTRFS: Transaction aborted (error %d)\n", 260 errno); 261 } 262 trans->aborted = errno; 263 /* Nothing used. The other threads that have joined this 264 * transaction may be able to continue. */ 265 if (!trans->blocks_used && list_empty(&trans->new_bgs)) { 266 const char *errstr; 267 268 errstr = btrfs_decode_error(errno); 269 btrfs_warn(root->fs_info, 270 "%s:%d: Aborting unused transaction(%s).", 271 function, line, errstr); 272 return; 273 } 274 ACCESS_ONCE(trans->transaction->aborted) = errno; 275 /* Wake up anybody who may be waiting on this transaction */ 276 wake_up(&root->fs_info->transaction_wait); 277 wake_up(&root->fs_info->transaction_blocked_wait); 278 __btrfs_std_error(root->fs_info, function, line, errno, NULL); 279 } 280 /* 281 * __btrfs_panic decodes unexpected, fatal errors from the caller, 282 * issues an alert, and either panics or BUGs, depending on mount options. 283 */ 284 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, 285 unsigned int line, int errno, const char *fmt, ...) 286 { 287 char *s_id = "<unknown>"; 288 const char *errstr; 289 struct va_format vaf = { .fmt = fmt }; 290 va_list args; 291 292 if (fs_info) 293 s_id = fs_info->sb->s_id; 294 295 va_start(args, fmt); 296 vaf.va = &args; 297 298 errstr = btrfs_decode_error(errno); 299 if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR)) 300 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n", 301 s_id, function, line, &vaf, errno, errstr); 302 303 btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)", 304 function, line, &vaf, errno, errstr); 305 va_end(args); 306 /* Caller calls BUG() */ 307 } 308 309 static void btrfs_put_super(struct super_block *sb) 310 { 311 close_ctree(btrfs_sb(sb)->tree_root); 312 } 313 314 enum { 315 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, 316 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, 317 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, 318 Opt_compress_type, Opt_compress_force, Opt_compress_force_type, 319 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, 320 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, 321 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache, 322 Opt_no_space_cache, Opt_recovery, Opt_skip_balance, 323 Opt_check_integrity, Opt_check_integrity_including_extent_data, 324 Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree, 325 Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard, 326 Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow, 327 Opt_datasum, Opt_treelog, Opt_noinode_cache, 328 Opt_err, 329 }; 330 331 static 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_flushoncommit, "flushoncommit"}, 357 {Opt_noflushoncommit, "noflushoncommit"}, 358 {Opt_ratio, "metadata_ratio=%d"}, 359 {Opt_discard, "discard"}, 360 {Opt_nodiscard, "nodiscard"}, 361 {Opt_space_cache, "space_cache"}, 362 {Opt_clear_cache, "clear_cache"}, 363 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, 364 {Opt_enospc_debug, "enospc_debug"}, 365 {Opt_noenospc_debug, "noenospc_debug"}, 366 {Opt_subvolrootid, "subvolrootid=%d"}, 367 {Opt_defrag, "autodefrag"}, 368 {Opt_nodefrag, "noautodefrag"}, 369 {Opt_inode_cache, "inode_cache"}, 370 {Opt_noinode_cache, "noinode_cache"}, 371 {Opt_no_space_cache, "nospace_cache"}, 372 {Opt_recovery, "recovery"}, 373 {Opt_skip_balance, "skip_balance"}, 374 {Opt_check_integrity, "check_int"}, 375 {Opt_check_integrity_including_extent_data, "check_int_data"}, 376 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"}, 377 {Opt_rescan_uuid_tree, "rescan_uuid_tree"}, 378 {Opt_fatal_errors, "fatal_errors=%s"}, 379 {Opt_commit_interval, "commit=%d"}, 380 {Opt_err, NULL}, 381 }; 382 383 /* 384 * Regular mount options parser. Everything that is needed only when 385 * reading in a new superblock is parsed here. 386 * XXX JDM: This needs to be cleaned up for remount. 387 */ 388 int btrfs_parse_options(struct btrfs_root *root, char *options) 389 { 390 struct btrfs_fs_info *info = root->fs_info; 391 substring_t args[MAX_OPT_ARGS]; 392 char *p, *num, *orig = NULL; 393 u64 cache_gen; 394 int intarg; 395 int ret = 0; 396 char *compress_type; 397 bool compress_force = false; 398 399 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); 400 if (cache_gen) 401 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 402 403 if (!options) 404 goto out; 405 406 /* 407 * strsep changes the string, duplicate it because parse_options 408 * gets called twice 409 */ 410 options = kstrdup(options, GFP_NOFS); 411 if (!options) 412 return -ENOMEM; 413 414 orig = options; 415 416 while ((p = strsep(&options, ",")) != NULL) { 417 int token; 418 if (!*p) 419 continue; 420 421 token = match_token(p, tokens, args); 422 switch (token) { 423 case Opt_degraded: 424 btrfs_info(root->fs_info, "allowing degraded mounts"); 425 btrfs_set_opt(info->mount_opt, DEGRADED); 426 break; 427 case Opt_subvol: 428 case Opt_subvolid: 429 case Opt_subvolrootid: 430 case Opt_device: 431 /* 432 * These are parsed by btrfs_parse_early_options 433 * and can be happily ignored here. 434 */ 435 break; 436 case Opt_nodatasum: 437 btrfs_set_and_info(root, NODATASUM, 438 "setting nodatasum"); 439 break; 440 case Opt_datasum: 441 if (btrfs_test_opt(root, NODATASUM)) { 442 if (btrfs_test_opt(root, NODATACOW)) 443 btrfs_info(root->fs_info, "setting datasum, datacow enabled"); 444 else 445 btrfs_info(root->fs_info, "setting datasum"); 446 } 447 btrfs_clear_opt(info->mount_opt, NODATACOW); 448 btrfs_clear_opt(info->mount_opt, NODATASUM); 449 break; 450 case Opt_nodatacow: 451 if (!btrfs_test_opt(root, NODATACOW)) { 452 if (!btrfs_test_opt(root, COMPRESS) || 453 !btrfs_test_opt(root, FORCE_COMPRESS)) { 454 btrfs_info(root->fs_info, 455 "setting nodatacow, compression disabled"); 456 } else { 457 btrfs_info(root->fs_info, "setting nodatacow"); 458 } 459 } 460 btrfs_clear_opt(info->mount_opt, COMPRESS); 461 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 462 btrfs_set_opt(info->mount_opt, NODATACOW); 463 btrfs_set_opt(info->mount_opt, NODATASUM); 464 break; 465 case Opt_datacow: 466 btrfs_clear_and_info(root, NODATACOW, 467 "setting datacow"); 468 break; 469 case Opt_compress_force: 470 case Opt_compress_force_type: 471 compress_force = true; 472 /* Fallthrough */ 473 case Opt_compress: 474 case Opt_compress_type: 475 if (token == Opt_compress || 476 token == Opt_compress_force || 477 strcmp(args[0].from, "zlib") == 0) { 478 compress_type = "zlib"; 479 info->compress_type = BTRFS_COMPRESS_ZLIB; 480 btrfs_set_opt(info->mount_opt, COMPRESS); 481 btrfs_clear_opt(info->mount_opt, NODATACOW); 482 btrfs_clear_opt(info->mount_opt, NODATASUM); 483 } else if (strcmp(args[0].from, "lzo") == 0) { 484 compress_type = "lzo"; 485 info->compress_type = BTRFS_COMPRESS_LZO; 486 btrfs_set_opt(info->mount_opt, COMPRESS); 487 btrfs_clear_opt(info->mount_opt, NODATACOW); 488 btrfs_clear_opt(info->mount_opt, NODATASUM); 489 btrfs_set_fs_incompat(info, COMPRESS_LZO); 490 } else if (strncmp(args[0].from, "no", 2) == 0) { 491 compress_type = "no"; 492 btrfs_clear_opt(info->mount_opt, COMPRESS); 493 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 494 compress_force = false; 495 } else { 496 ret = -EINVAL; 497 goto out; 498 } 499 500 if (compress_force) { 501 btrfs_set_and_info(root, FORCE_COMPRESS, 502 "force %s compression", 503 compress_type); 504 } else { 505 if (!btrfs_test_opt(root, COMPRESS)) 506 btrfs_info(root->fs_info, 507 "btrfs: use %s compression", 508 compress_type); 509 /* 510 * If we remount from compress-force=xxx to 511 * compress=xxx, we need clear FORCE_COMPRESS 512 * flag, otherwise, there is no way for users 513 * to disable forcible compression separately. 514 */ 515 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 516 } 517 break; 518 case Opt_ssd: 519 btrfs_set_and_info(root, SSD, 520 "use ssd allocation scheme"); 521 break; 522 case Opt_ssd_spread: 523 btrfs_set_and_info(root, SSD_SPREAD, 524 "use spread ssd allocation scheme"); 525 btrfs_set_opt(info->mount_opt, SSD); 526 break; 527 case Opt_nossd: 528 btrfs_set_and_info(root, NOSSD, 529 "not using ssd allocation scheme"); 530 btrfs_clear_opt(info->mount_opt, SSD); 531 break; 532 case Opt_barrier: 533 btrfs_clear_and_info(root, NOBARRIER, 534 "turning on barriers"); 535 break; 536 case Opt_nobarrier: 537 btrfs_set_and_info(root, NOBARRIER, 538 "turning off barriers"); 539 break; 540 case Opt_thread_pool: 541 ret = match_int(&args[0], &intarg); 542 if (ret) { 543 goto out; 544 } else if (intarg > 0) { 545 info->thread_pool_size = intarg; 546 } else { 547 ret = -EINVAL; 548 goto out; 549 } 550 break; 551 case Opt_max_inline: 552 num = match_strdup(&args[0]); 553 if (num) { 554 info->max_inline = memparse(num, NULL); 555 kfree(num); 556 557 if (info->max_inline) { 558 info->max_inline = min_t(u64, 559 info->max_inline, 560 root->sectorsize); 561 } 562 btrfs_info(root->fs_info, "max_inline at %llu", 563 info->max_inline); 564 } else { 565 ret = -ENOMEM; 566 goto out; 567 } 568 break; 569 case Opt_alloc_start: 570 num = match_strdup(&args[0]); 571 if (num) { 572 mutex_lock(&info->chunk_mutex); 573 info->alloc_start = memparse(num, NULL); 574 mutex_unlock(&info->chunk_mutex); 575 kfree(num); 576 btrfs_info(root->fs_info, "allocations start at %llu", 577 info->alloc_start); 578 } else { 579 ret = -ENOMEM; 580 goto out; 581 } 582 break; 583 case Opt_acl: 584 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 585 root->fs_info->sb->s_flags |= MS_POSIXACL; 586 break; 587 #else 588 btrfs_err(root->fs_info, 589 "support for ACL not compiled in!"); 590 ret = -EINVAL; 591 goto out; 592 #endif 593 case Opt_noacl: 594 root->fs_info->sb->s_flags &= ~MS_POSIXACL; 595 break; 596 case Opt_notreelog: 597 btrfs_set_and_info(root, NOTREELOG, 598 "disabling tree log"); 599 break; 600 case Opt_treelog: 601 btrfs_clear_and_info(root, NOTREELOG, 602 "enabling tree log"); 603 break; 604 case Opt_flushoncommit: 605 btrfs_set_and_info(root, FLUSHONCOMMIT, 606 "turning on flush-on-commit"); 607 break; 608 case Opt_noflushoncommit: 609 btrfs_clear_and_info(root, FLUSHONCOMMIT, 610 "turning off flush-on-commit"); 611 break; 612 case Opt_ratio: 613 ret = match_int(&args[0], &intarg); 614 if (ret) { 615 goto out; 616 } else if (intarg >= 0) { 617 info->metadata_ratio = intarg; 618 btrfs_info(root->fs_info, "metadata ratio %d", 619 info->metadata_ratio); 620 } else { 621 ret = -EINVAL; 622 goto out; 623 } 624 break; 625 case Opt_discard: 626 btrfs_set_and_info(root, DISCARD, 627 "turning on discard"); 628 break; 629 case Opt_nodiscard: 630 btrfs_clear_and_info(root, DISCARD, 631 "turning off discard"); 632 break; 633 case Opt_space_cache: 634 btrfs_set_and_info(root, SPACE_CACHE, 635 "enabling disk space caching"); 636 break; 637 case Opt_rescan_uuid_tree: 638 btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE); 639 break; 640 case Opt_no_space_cache: 641 btrfs_clear_and_info(root, SPACE_CACHE, 642 "disabling disk space caching"); 643 break; 644 case Opt_inode_cache: 645 btrfs_set_pending_and_info(info, INODE_MAP_CACHE, 646 "enabling inode map caching"); 647 break; 648 case Opt_noinode_cache: 649 btrfs_clear_pending_and_info(info, INODE_MAP_CACHE, 650 "disabling inode map caching"); 651 break; 652 case Opt_clear_cache: 653 btrfs_set_and_info(root, CLEAR_CACHE, 654 "force clearing of disk cache"); 655 break; 656 case Opt_user_subvol_rm_allowed: 657 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 658 break; 659 case Opt_enospc_debug: 660 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 661 break; 662 case Opt_noenospc_debug: 663 btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG); 664 break; 665 case Opt_defrag: 666 btrfs_set_and_info(root, AUTO_DEFRAG, 667 "enabling auto defrag"); 668 break; 669 case Opt_nodefrag: 670 btrfs_clear_and_info(root, AUTO_DEFRAG, 671 "disabling auto defrag"); 672 break; 673 case Opt_recovery: 674 btrfs_info(root->fs_info, "enabling auto recovery"); 675 btrfs_set_opt(info->mount_opt, RECOVERY); 676 break; 677 case Opt_skip_balance: 678 btrfs_set_opt(info->mount_opt, SKIP_BALANCE); 679 break; 680 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 681 case Opt_check_integrity_including_extent_data: 682 btrfs_info(root->fs_info, 683 "enabling check integrity including extent data"); 684 btrfs_set_opt(info->mount_opt, 685 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); 686 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 687 break; 688 case Opt_check_integrity: 689 btrfs_info(root->fs_info, "enabling check integrity"); 690 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 691 break; 692 case Opt_check_integrity_print_mask: 693 ret = match_int(&args[0], &intarg); 694 if (ret) { 695 goto out; 696 } else if (intarg >= 0) { 697 info->check_integrity_print_mask = intarg; 698 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x", 699 info->check_integrity_print_mask); 700 } else { 701 ret = -EINVAL; 702 goto out; 703 } 704 break; 705 #else 706 case Opt_check_integrity_including_extent_data: 707 case Opt_check_integrity: 708 case Opt_check_integrity_print_mask: 709 btrfs_err(root->fs_info, 710 "support for check_integrity* not compiled in!"); 711 ret = -EINVAL; 712 goto out; 713 #endif 714 case Opt_fatal_errors: 715 if (strcmp(args[0].from, "panic") == 0) 716 btrfs_set_opt(info->mount_opt, 717 PANIC_ON_FATAL_ERROR); 718 else if (strcmp(args[0].from, "bug") == 0) 719 btrfs_clear_opt(info->mount_opt, 720 PANIC_ON_FATAL_ERROR); 721 else { 722 ret = -EINVAL; 723 goto out; 724 } 725 break; 726 case Opt_commit_interval: 727 intarg = 0; 728 ret = match_int(&args[0], &intarg); 729 if (ret < 0) { 730 btrfs_err(root->fs_info, "invalid commit interval"); 731 ret = -EINVAL; 732 goto out; 733 } 734 if (intarg > 0) { 735 if (intarg > 300) { 736 btrfs_warn(root->fs_info, "excessive commit interval %d", 737 intarg); 738 } 739 info->commit_interval = intarg; 740 } else { 741 btrfs_info(root->fs_info, "using default commit interval %ds", 742 BTRFS_DEFAULT_COMMIT_INTERVAL); 743 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL; 744 } 745 break; 746 case Opt_err: 747 btrfs_info(root->fs_info, "unrecognized mount option '%s'", p); 748 ret = -EINVAL; 749 goto out; 750 default: 751 break; 752 } 753 } 754 out: 755 if (!ret && btrfs_test_opt(root, SPACE_CACHE)) 756 btrfs_info(root->fs_info, "disk space caching is enabled"); 757 kfree(orig); 758 return ret; 759 } 760 761 /* 762 * Parse mount options that are required early in the mount process. 763 * 764 * All other options will be parsed on much later in the mount process and 765 * only when we need to allocate a new super block. 766 */ 767 static int btrfs_parse_early_options(const char *options, fmode_t flags, 768 void *holder, char **subvol_name, u64 *subvol_objectid, 769 struct btrfs_fs_devices **fs_devices) 770 { 771 substring_t args[MAX_OPT_ARGS]; 772 char *device_name, *opts, *orig, *p; 773 char *num = NULL; 774 int error = 0; 775 776 if (!options) 777 return 0; 778 779 /* 780 * strsep changes the string, duplicate it because parse_options 781 * gets called twice 782 */ 783 opts = kstrdup(options, GFP_KERNEL); 784 if (!opts) 785 return -ENOMEM; 786 orig = opts; 787 788 while ((p = strsep(&opts, ",")) != NULL) { 789 int token; 790 if (!*p) 791 continue; 792 793 token = match_token(p, tokens, args); 794 switch (token) { 795 case Opt_subvol: 796 kfree(*subvol_name); 797 *subvol_name = match_strdup(&args[0]); 798 if (!*subvol_name) { 799 error = -ENOMEM; 800 goto out; 801 } 802 break; 803 case Opt_subvolid: 804 num = match_strdup(&args[0]); 805 if (num) { 806 *subvol_objectid = memparse(num, NULL); 807 kfree(num); 808 /* we want the original fs_tree */ 809 if (!*subvol_objectid) 810 *subvol_objectid = 811 BTRFS_FS_TREE_OBJECTID; 812 } else { 813 error = -EINVAL; 814 goto out; 815 } 816 break; 817 case Opt_subvolrootid: 818 printk(KERN_WARNING 819 "BTRFS: 'subvolrootid' mount option is deprecated and has " 820 "no effect\n"); 821 break; 822 case Opt_device: 823 device_name = match_strdup(&args[0]); 824 if (!device_name) { 825 error = -ENOMEM; 826 goto out; 827 } 828 error = btrfs_scan_one_device(device_name, 829 flags, holder, fs_devices); 830 kfree(device_name); 831 if (error) 832 goto out; 833 break; 834 default: 835 break; 836 } 837 } 838 839 out: 840 kfree(orig); 841 return error; 842 } 843 844 static struct dentry *get_default_root(struct super_block *sb, 845 u64 subvol_objectid) 846 { 847 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 848 struct btrfs_root *root = fs_info->tree_root; 849 struct btrfs_root *new_root; 850 struct btrfs_dir_item *di; 851 struct btrfs_path *path; 852 struct btrfs_key location; 853 struct inode *inode; 854 u64 dir_id; 855 int new = 0; 856 857 /* 858 * We have a specific subvol we want to mount, just setup location and 859 * go look up the root. 860 */ 861 if (subvol_objectid) { 862 location.objectid = subvol_objectid; 863 location.type = BTRFS_ROOT_ITEM_KEY; 864 location.offset = (u64)-1; 865 goto find_root; 866 } 867 868 path = btrfs_alloc_path(); 869 if (!path) 870 return ERR_PTR(-ENOMEM); 871 path->leave_spinning = 1; 872 873 /* 874 * Find the "default" dir item which points to the root item that we 875 * will mount by default if we haven't been given a specific subvolume 876 * to mount. 877 */ 878 dir_id = btrfs_super_root_dir(fs_info->super_copy); 879 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 880 if (IS_ERR(di)) { 881 btrfs_free_path(path); 882 return ERR_CAST(di); 883 } 884 if (!di) { 885 /* 886 * Ok the default dir item isn't there. This is weird since 887 * it's always been there, but don't freak out, just try and 888 * mount to root most subvolume. 889 */ 890 btrfs_free_path(path); 891 dir_id = BTRFS_FIRST_FREE_OBJECTID; 892 new_root = fs_info->fs_root; 893 goto setup_root; 894 } 895 896 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 897 btrfs_free_path(path); 898 899 find_root: 900 new_root = btrfs_read_fs_root_no_name(fs_info, &location); 901 if (IS_ERR(new_root)) 902 return ERR_CAST(new_root); 903 904 dir_id = btrfs_root_dirid(&new_root->root_item); 905 setup_root: 906 location.objectid = dir_id; 907 location.type = BTRFS_INODE_ITEM_KEY; 908 location.offset = 0; 909 910 inode = btrfs_iget(sb, &location, new_root, &new); 911 if (IS_ERR(inode)) 912 return ERR_CAST(inode); 913 914 /* 915 * If we're just mounting the root most subvol put the inode and return 916 * a reference to the dentry. We will have already gotten a reference 917 * to the inode in btrfs_fill_super so we're good to go. 918 */ 919 if (!new && sb->s_root->d_inode == inode) { 920 iput(inode); 921 return dget(sb->s_root); 922 } 923 924 return d_obtain_root(inode); 925 } 926 927 static int btrfs_fill_super(struct super_block *sb, 928 struct btrfs_fs_devices *fs_devices, 929 void *data, int silent) 930 { 931 struct inode *inode; 932 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 933 struct btrfs_key key; 934 int err; 935 936 sb->s_maxbytes = MAX_LFS_FILESIZE; 937 sb->s_magic = BTRFS_SUPER_MAGIC; 938 sb->s_op = &btrfs_super_ops; 939 sb->s_d_op = &btrfs_dentry_operations; 940 sb->s_export_op = &btrfs_export_ops; 941 sb->s_xattr = btrfs_xattr_handlers; 942 sb->s_time_gran = 1; 943 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 944 sb->s_flags |= MS_POSIXACL; 945 #endif 946 sb->s_flags |= MS_I_VERSION; 947 err = open_ctree(sb, fs_devices, (char *)data); 948 if (err) { 949 printk(KERN_ERR "BTRFS: open_ctree failed\n"); 950 return err; 951 } 952 953 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 954 key.type = BTRFS_INODE_ITEM_KEY; 955 key.offset = 0; 956 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL); 957 if (IS_ERR(inode)) { 958 err = PTR_ERR(inode); 959 goto fail_close; 960 } 961 962 sb->s_root = d_make_root(inode); 963 if (!sb->s_root) { 964 err = -ENOMEM; 965 goto fail_close; 966 } 967 968 save_mount_options(sb, data); 969 cleancache_init_fs(sb); 970 sb->s_flags |= MS_ACTIVE; 971 return 0; 972 973 fail_close: 974 close_ctree(fs_info->tree_root); 975 return err; 976 } 977 978 int btrfs_sync_fs(struct super_block *sb, int wait) 979 { 980 struct btrfs_trans_handle *trans; 981 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 982 struct btrfs_root *root = fs_info->tree_root; 983 984 trace_btrfs_sync_fs(wait); 985 986 if (!wait) { 987 filemap_flush(fs_info->btree_inode->i_mapping); 988 return 0; 989 } 990 991 btrfs_wait_ordered_roots(fs_info, -1); 992 993 trans = btrfs_attach_transaction_barrier(root); 994 if (IS_ERR(trans)) { 995 /* no transaction, don't bother */ 996 if (PTR_ERR(trans) == -ENOENT) { 997 /* 998 * Exit unless we have some pending changes 999 * that need to go through commit 1000 */ 1001 if (fs_info->pending_changes == 0) 1002 return 0; 1003 /* 1004 * A non-blocking test if the fs is frozen. We must not 1005 * start a new transaction here otherwise a deadlock 1006 * happens. The pending operations are delayed to the 1007 * next commit after thawing. 1008 */ 1009 if (__sb_start_write(sb, SB_FREEZE_WRITE, false)) 1010 __sb_end_write(sb, SB_FREEZE_WRITE); 1011 else 1012 return 0; 1013 trans = btrfs_start_transaction(root, 0); 1014 } 1015 if (IS_ERR(trans)) 1016 return PTR_ERR(trans); 1017 } 1018 return btrfs_commit_transaction(trans, root); 1019 } 1020 1021 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) 1022 { 1023 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); 1024 struct btrfs_root *root = info->tree_root; 1025 char *compress_type; 1026 1027 if (btrfs_test_opt(root, DEGRADED)) 1028 seq_puts(seq, ",degraded"); 1029 if (btrfs_test_opt(root, NODATASUM)) 1030 seq_puts(seq, ",nodatasum"); 1031 if (btrfs_test_opt(root, NODATACOW)) 1032 seq_puts(seq, ",nodatacow"); 1033 if (btrfs_test_opt(root, NOBARRIER)) 1034 seq_puts(seq, ",nobarrier"); 1035 if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE) 1036 seq_printf(seq, ",max_inline=%llu", info->max_inline); 1037 if (info->alloc_start != 0) 1038 seq_printf(seq, ",alloc_start=%llu", info->alloc_start); 1039 if (info->thread_pool_size != min_t(unsigned long, 1040 num_online_cpus() + 2, 8)) 1041 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 1042 if (btrfs_test_opt(root, COMPRESS)) { 1043 if (info->compress_type == BTRFS_COMPRESS_ZLIB) 1044 compress_type = "zlib"; 1045 else 1046 compress_type = "lzo"; 1047 if (btrfs_test_opt(root, FORCE_COMPRESS)) 1048 seq_printf(seq, ",compress-force=%s", compress_type); 1049 else 1050 seq_printf(seq, ",compress=%s", compress_type); 1051 } 1052 if (btrfs_test_opt(root, NOSSD)) 1053 seq_puts(seq, ",nossd"); 1054 if (btrfs_test_opt(root, SSD_SPREAD)) 1055 seq_puts(seq, ",ssd_spread"); 1056 else if (btrfs_test_opt(root, SSD)) 1057 seq_puts(seq, ",ssd"); 1058 if (btrfs_test_opt(root, NOTREELOG)) 1059 seq_puts(seq, ",notreelog"); 1060 if (btrfs_test_opt(root, FLUSHONCOMMIT)) 1061 seq_puts(seq, ",flushoncommit"); 1062 if (btrfs_test_opt(root, DISCARD)) 1063 seq_puts(seq, ",discard"); 1064 if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) 1065 seq_puts(seq, ",noacl"); 1066 if (btrfs_test_opt(root, SPACE_CACHE)) 1067 seq_puts(seq, ",space_cache"); 1068 else 1069 seq_puts(seq, ",nospace_cache"); 1070 if (btrfs_test_opt(root, RESCAN_UUID_TREE)) 1071 seq_puts(seq, ",rescan_uuid_tree"); 1072 if (btrfs_test_opt(root, CLEAR_CACHE)) 1073 seq_puts(seq, ",clear_cache"); 1074 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 1075 seq_puts(seq, ",user_subvol_rm_allowed"); 1076 if (btrfs_test_opt(root, ENOSPC_DEBUG)) 1077 seq_puts(seq, ",enospc_debug"); 1078 if (btrfs_test_opt(root, AUTO_DEFRAG)) 1079 seq_puts(seq, ",autodefrag"); 1080 if (btrfs_test_opt(root, INODE_MAP_CACHE)) 1081 seq_puts(seq, ",inode_cache"); 1082 if (btrfs_test_opt(root, SKIP_BALANCE)) 1083 seq_puts(seq, ",skip_balance"); 1084 if (btrfs_test_opt(root, RECOVERY)) 1085 seq_puts(seq, ",recovery"); 1086 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 1087 if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA)) 1088 seq_puts(seq, ",check_int_data"); 1089 else if (btrfs_test_opt(root, CHECK_INTEGRITY)) 1090 seq_puts(seq, ",check_int"); 1091 if (info->check_integrity_print_mask) 1092 seq_printf(seq, ",check_int_print_mask=%d", 1093 info->check_integrity_print_mask); 1094 #endif 1095 if (info->metadata_ratio) 1096 seq_printf(seq, ",metadata_ratio=%d", 1097 info->metadata_ratio); 1098 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR)) 1099 seq_puts(seq, ",fatal_errors=panic"); 1100 if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL) 1101 seq_printf(seq, ",commit=%d", info->commit_interval); 1102 return 0; 1103 } 1104 1105 static int btrfs_test_super(struct super_block *s, void *data) 1106 { 1107 struct btrfs_fs_info *p = data; 1108 struct btrfs_fs_info *fs_info = btrfs_sb(s); 1109 1110 return fs_info->fs_devices == p->fs_devices; 1111 } 1112 1113 static int btrfs_set_super(struct super_block *s, void *data) 1114 { 1115 int err = set_anon_super(s, data); 1116 if (!err) 1117 s->s_fs_info = data; 1118 return err; 1119 } 1120 1121 /* 1122 * subvolumes are identified by ino 256 1123 */ 1124 static inline int is_subvolume_inode(struct inode *inode) 1125 { 1126 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 1127 return 1; 1128 return 0; 1129 } 1130 1131 /* 1132 * This will strip out the subvol=%s argument for an argument string and add 1133 * subvolid=0 to make sure we get the actual tree root for path walking to the 1134 * subvol we want. 1135 */ 1136 static char *setup_root_args(char *args) 1137 { 1138 unsigned len = strlen(args) + 2 + 1; 1139 char *src, *dst, *buf; 1140 1141 /* 1142 * We need the same args as before, but with this substitution: 1143 * s!subvol=[^,]+!subvolid=0! 1144 * 1145 * Since the replacement string is up to 2 bytes longer than the 1146 * original, allocate strlen(args) + 2 + 1 bytes. 1147 */ 1148 1149 src = strstr(args, "subvol="); 1150 /* This shouldn't happen, but just in case.. */ 1151 if (!src) 1152 return NULL; 1153 1154 buf = dst = kmalloc(len, GFP_NOFS); 1155 if (!buf) 1156 return NULL; 1157 1158 /* 1159 * If the subvol= arg is not at the start of the string, 1160 * copy whatever precedes it into buf. 1161 */ 1162 if (src != args) { 1163 *src++ = '\0'; 1164 strcpy(buf, args); 1165 dst += strlen(args); 1166 } 1167 1168 strcpy(dst, "subvolid=0"); 1169 dst += strlen("subvolid=0"); 1170 1171 /* 1172 * If there is a "," after the original subvol=... string, 1173 * copy that suffix into our buffer. Otherwise, we're done. 1174 */ 1175 src = strchr(src, ','); 1176 if (src) 1177 strcpy(dst, src); 1178 1179 return buf; 1180 } 1181 1182 static struct dentry *mount_subvol(const char *subvol_name, int flags, 1183 const char *device_name, char *data) 1184 { 1185 struct dentry *root; 1186 struct vfsmount *mnt; 1187 char *newargs; 1188 1189 newargs = setup_root_args(data); 1190 if (!newargs) 1191 return ERR_PTR(-ENOMEM); 1192 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, 1193 newargs); 1194 1195 if (PTR_RET(mnt) == -EBUSY) { 1196 if (flags & MS_RDONLY) { 1197 mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, device_name, 1198 newargs); 1199 } else { 1200 int r; 1201 mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name, 1202 newargs); 1203 if (IS_ERR(mnt)) { 1204 kfree(newargs); 1205 return ERR_CAST(mnt); 1206 } 1207 1208 r = btrfs_remount(mnt->mnt_sb, &flags, NULL); 1209 if (r < 0) { 1210 /* FIXME: release vfsmount mnt ??*/ 1211 kfree(newargs); 1212 return ERR_PTR(r); 1213 } 1214 } 1215 } 1216 1217 kfree(newargs); 1218 1219 if (IS_ERR(mnt)) 1220 return ERR_CAST(mnt); 1221 1222 root = mount_subtree(mnt, subvol_name); 1223 1224 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) { 1225 struct super_block *s = root->d_sb; 1226 dput(root); 1227 root = ERR_PTR(-EINVAL); 1228 deactivate_locked_super(s); 1229 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n", 1230 subvol_name); 1231 } 1232 1233 return root; 1234 } 1235 1236 static int parse_security_options(char *orig_opts, 1237 struct security_mnt_opts *sec_opts) 1238 { 1239 char *secdata = NULL; 1240 int ret = 0; 1241 1242 secdata = alloc_secdata(); 1243 if (!secdata) 1244 return -ENOMEM; 1245 ret = security_sb_copy_data(orig_opts, secdata); 1246 if (ret) { 1247 free_secdata(secdata); 1248 return ret; 1249 } 1250 ret = security_sb_parse_opts_str(secdata, sec_opts); 1251 free_secdata(secdata); 1252 return ret; 1253 } 1254 1255 static int setup_security_options(struct btrfs_fs_info *fs_info, 1256 struct super_block *sb, 1257 struct security_mnt_opts *sec_opts) 1258 { 1259 int ret = 0; 1260 1261 /* 1262 * Call security_sb_set_mnt_opts() to check whether new sec_opts 1263 * is valid. 1264 */ 1265 ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL); 1266 if (ret) 1267 return ret; 1268 1269 #ifdef CONFIG_SECURITY 1270 if (!fs_info->security_opts.num_mnt_opts) { 1271 /* first time security setup, copy sec_opts to fs_info */ 1272 memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts)); 1273 } else { 1274 /* 1275 * Since SELinux(the only one supports security_mnt_opts) does 1276 * NOT support changing context during remount/mount same sb, 1277 * This must be the same or part of the same security options, 1278 * just free it. 1279 */ 1280 security_free_mnt_opts(sec_opts); 1281 } 1282 #endif 1283 return ret; 1284 } 1285 1286 /* 1287 * Find a superblock for the given device / mount point. 1288 * 1289 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 1290 * for multiple device setup. Make sure to keep it in sync. 1291 */ 1292 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 1293 const char *device_name, void *data) 1294 { 1295 struct block_device *bdev = NULL; 1296 struct super_block *s; 1297 struct dentry *root; 1298 struct btrfs_fs_devices *fs_devices = NULL; 1299 struct btrfs_fs_info *fs_info = NULL; 1300 struct security_mnt_opts new_sec_opts; 1301 fmode_t mode = FMODE_READ; 1302 char *subvol_name = NULL; 1303 u64 subvol_objectid = 0; 1304 int error = 0; 1305 1306 if (!(flags & MS_RDONLY)) 1307 mode |= FMODE_WRITE; 1308 1309 error = btrfs_parse_early_options(data, mode, fs_type, 1310 &subvol_name, &subvol_objectid, 1311 &fs_devices); 1312 if (error) { 1313 kfree(subvol_name); 1314 return ERR_PTR(error); 1315 } 1316 1317 if (subvol_name) { 1318 root = mount_subvol(subvol_name, flags, device_name, data); 1319 kfree(subvol_name); 1320 return root; 1321 } 1322 1323 security_init_mnt_opts(&new_sec_opts); 1324 if (data) { 1325 error = parse_security_options(data, &new_sec_opts); 1326 if (error) 1327 return ERR_PTR(error); 1328 } 1329 1330 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); 1331 if (error) 1332 goto error_sec_opts; 1333 1334 /* 1335 * Setup a dummy root and fs_info for test/set super. This is because 1336 * we don't actually fill this stuff out until open_ctree, but we need 1337 * it for searching for existing supers, so this lets us do that and 1338 * then open_ctree will properly initialize everything later. 1339 */ 1340 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); 1341 if (!fs_info) { 1342 error = -ENOMEM; 1343 goto error_sec_opts; 1344 } 1345 1346 fs_info->fs_devices = fs_devices; 1347 1348 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1349 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1350 security_init_mnt_opts(&fs_info->security_opts); 1351 if (!fs_info->super_copy || !fs_info->super_for_commit) { 1352 error = -ENOMEM; 1353 goto error_fs_info; 1354 } 1355 1356 error = btrfs_open_devices(fs_devices, mode, fs_type); 1357 if (error) 1358 goto error_fs_info; 1359 1360 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 1361 error = -EACCES; 1362 goto error_close_devices; 1363 } 1364 1365 bdev = fs_devices->latest_bdev; 1366 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC, 1367 fs_info); 1368 if (IS_ERR(s)) { 1369 error = PTR_ERR(s); 1370 goto error_close_devices; 1371 } 1372 1373 if (s->s_root) { 1374 btrfs_close_devices(fs_devices); 1375 free_fs_info(fs_info); 1376 if ((flags ^ s->s_flags) & MS_RDONLY) 1377 error = -EBUSY; 1378 } else { 1379 char b[BDEVNAME_SIZE]; 1380 1381 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); 1382 btrfs_sb(s)->bdev_holder = fs_type; 1383 error = btrfs_fill_super(s, fs_devices, data, 1384 flags & MS_SILENT ? 1 : 0); 1385 } 1386 1387 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error); 1388 if (IS_ERR(root)) { 1389 deactivate_locked_super(s); 1390 error = PTR_ERR(root); 1391 goto error_sec_opts; 1392 } 1393 1394 fs_info = btrfs_sb(s); 1395 error = setup_security_options(fs_info, s, &new_sec_opts); 1396 if (error) { 1397 dput(root); 1398 deactivate_locked_super(s); 1399 goto error_sec_opts; 1400 } 1401 1402 return root; 1403 1404 error_close_devices: 1405 btrfs_close_devices(fs_devices); 1406 error_fs_info: 1407 free_fs_info(fs_info); 1408 error_sec_opts: 1409 security_free_mnt_opts(&new_sec_opts); 1410 return ERR_PTR(error); 1411 } 1412 1413 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, 1414 int new_pool_size, int old_pool_size) 1415 { 1416 if (new_pool_size == old_pool_size) 1417 return; 1418 1419 fs_info->thread_pool_size = new_pool_size; 1420 1421 btrfs_info(fs_info, "resize thread pool %d -> %d", 1422 old_pool_size, new_pool_size); 1423 1424 btrfs_workqueue_set_max(fs_info->workers, new_pool_size); 1425 btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size); 1426 btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size); 1427 btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size); 1428 btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size); 1429 btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size); 1430 btrfs_workqueue_set_max(fs_info->endio_meta_write_workers, 1431 new_pool_size); 1432 btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size); 1433 btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size); 1434 btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size); 1435 btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size); 1436 btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers, 1437 new_pool_size); 1438 } 1439 1440 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info) 1441 { 1442 set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1443 } 1444 1445 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info, 1446 unsigned long old_opts, int flags) 1447 { 1448 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1449 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1450 (flags & MS_RDONLY))) { 1451 /* wait for any defraggers to finish */ 1452 wait_event(fs_info->transaction_wait, 1453 (atomic_read(&fs_info->defrag_running) == 0)); 1454 if (flags & MS_RDONLY) 1455 sync_filesystem(fs_info->sb); 1456 } 1457 } 1458 1459 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info, 1460 unsigned long old_opts) 1461 { 1462 /* 1463 * We need cleanup all defragable inodes if the autodefragment is 1464 * close or the fs is R/O. 1465 */ 1466 if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) && 1467 (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || 1468 (fs_info->sb->s_flags & MS_RDONLY))) { 1469 btrfs_cleanup_defrag_inodes(fs_info); 1470 } 1471 1472 clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state); 1473 } 1474 1475 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1476 { 1477 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1478 struct btrfs_root *root = fs_info->tree_root; 1479 unsigned old_flags = sb->s_flags; 1480 unsigned long old_opts = fs_info->mount_opt; 1481 unsigned long old_compress_type = fs_info->compress_type; 1482 u64 old_max_inline = fs_info->max_inline; 1483 u64 old_alloc_start = fs_info->alloc_start; 1484 int old_thread_pool_size = fs_info->thread_pool_size; 1485 unsigned int old_metadata_ratio = fs_info->metadata_ratio; 1486 int ret; 1487 1488 sync_filesystem(sb); 1489 btrfs_remount_prepare(fs_info); 1490 1491 if (data) { 1492 struct security_mnt_opts new_sec_opts; 1493 1494 security_init_mnt_opts(&new_sec_opts); 1495 ret = parse_security_options(data, &new_sec_opts); 1496 if (ret) 1497 goto restore; 1498 ret = setup_security_options(fs_info, sb, 1499 &new_sec_opts); 1500 if (ret) { 1501 security_free_mnt_opts(&new_sec_opts); 1502 goto restore; 1503 } 1504 } 1505 1506 ret = btrfs_parse_options(root, data); 1507 if (ret) { 1508 ret = -EINVAL; 1509 goto restore; 1510 } 1511 1512 btrfs_remount_begin(fs_info, old_opts, *flags); 1513 btrfs_resize_thread_pool(fs_info, 1514 fs_info->thread_pool_size, old_thread_pool_size); 1515 1516 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1517 goto out; 1518 1519 if (*flags & MS_RDONLY) { 1520 /* 1521 * this also happens on 'umount -rf' or on shutdown, when 1522 * the filesystem is busy. 1523 */ 1524 cancel_work_sync(&fs_info->async_reclaim_work); 1525 1526 /* wait for the uuid_scan task to finish */ 1527 down(&fs_info->uuid_tree_rescan_sem); 1528 /* avoid complains from lockdep et al. */ 1529 up(&fs_info->uuid_tree_rescan_sem); 1530 1531 sb->s_flags |= MS_RDONLY; 1532 1533 btrfs_dev_replace_suspend_for_unmount(fs_info); 1534 btrfs_scrub_cancel(fs_info); 1535 btrfs_pause_balance(fs_info); 1536 1537 ret = btrfs_commit_super(root); 1538 if (ret) 1539 goto restore; 1540 } else { 1541 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) { 1542 btrfs_err(fs_info, 1543 "Remounting read-write after error is not allowed"); 1544 ret = -EINVAL; 1545 goto restore; 1546 } 1547 if (fs_info->fs_devices->rw_devices == 0) { 1548 ret = -EACCES; 1549 goto restore; 1550 } 1551 1552 if (fs_info->fs_devices->missing_devices > 1553 fs_info->num_tolerated_disk_barrier_failures && 1554 !(*flags & MS_RDONLY)) { 1555 btrfs_warn(fs_info, 1556 "too many missing devices, writeable remount is not allowed"); 1557 ret = -EACCES; 1558 goto restore; 1559 } 1560 1561 if (btrfs_super_log_root(fs_info->super_copy) != 0) { 1562 ret = -EINVAL; 1563 goto restore; 1564 } 1565 1566 ret = btrfs_cleanup_fs_roots(fs_info); 1567 if (ret) 1568 goto restore; 1569 1570 /* recover relocation */ 1571 mutex_lock(&fs_info->cleaner_mutex); 1572 ret = btrfs_recover_relocation(root); 1573 mutex_unlock(&fs_info->cleaner_mutex); 1574 if (ret) 1575 goto restore; 1576 1577 ret = btrfs_resume_balance_async(fs_info); 1578 if (ret) 1579 goto restore; 1580 1581 ret = btrfs_resume_dev_replace_async(fs_info); 1582 if (ret) { 1583 btrfs_warn(fs_info, "failed to resume dev_replace"); 1584 goto restore; 1585 } 1586 1587 if (!fs_info->uuid_root) { 1588 btrfs_info(fs_info, "creating UUID tree"); 1589 ret = btrfs_create_uuid_tree(fs_info); 1590 if (ret) { 1591 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret); 1592 goto restore; 1593 } 1594 } 1595 sb->s_flags &= ~MS_RDONLY; 1596 } 1597 out: 1598 wake_up_process(fs_info->transaction_kthread); 1599 btrfs_remount_cleanup(fs_info, old_opts); 1600 return 0; 1601 1602 restore: 1603 /* We've hit an error - don't reset MS_RDONLY */ 1604 if (sb->s_flags & MS_RDONLY) 1605 old_flags |= MS_RDONLY; 1606 sb->s_flags = old_flags; 1607 fs_info->mount_opt = old_opts; 1608 fs_info->compress_type = old_compress_type; 1609 fs_info->max_inline = old_max_inline; 1610 mutex_lock(&fs_info->chunk_mutex); 1611 fs_info->alloc_start = old_alloc_start; 1612 mutex_unlock(&fs_info->chunk_mutex); 1613 btrfs_resize_thread_pool(fs_info, 1614 old_thread_pool_size, fs_info->thread_pool_size); 1615 fs_info->metadata_ratio = old_metadata_ratio; 1616 btrfs_remount_cleanup(fs_info, old_opts); 1617 return ret; 1618 } 1619 1620 /* Used to sort the devices by max_avail(descending sort) */ 1621 static int btrfs_cmp_device_free_bytes(const void *dev_info1, 1622 const void *dev_info2) 1623 { 1624 if (((struct btrfs_device_info *)dev_info1)->max_avail > 1625 ((struct btrfs_device_info *)dev_info2)->max_avail) 1626 return -1; 1627 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 1628 ((struct btrfs_device_info *)dev_info2)->max_avail) 1629 return 1; 1630 else 1631 return 0; 1632 } 1633 1634 /* 1635 * sort the devices by max_avail, in which max free extent size of each device 1636 * is stored.(Descending Sort) 1637 */ 1638 static inline void btrfs_descending_sort_devices( 1639 struct btrfs_device_info *devices, 1640 size_t nr_devices) 1641 { 1642 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1643 btrfs_cmp_device_free_bytes, NULL); 1644 } 1645 1646 /* 1647 * The helper to calc the free space on the devices that can be used to store 1648 * file data. 1649 */ 1650 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) 1651 { 1652 struct btrfs_fs_info *fs_info = root->fs_info; 1653 struct btrfs_device_info *devices_info; 1654 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1655 struct btrfs_device *device; 1656 u64 skip_space; 1657 u64 type; 1658 u64 avail_space; 1659 u64 used_space; 1660 u64 min_stripe_size; 1661 int min_stripes = 1, num_stripes = 1; 1662 int i = 0, nr_devices; 1663 int ret; 1664 1665 /* 1666 * We aren't under the device list lock, so this is racey-ish, but good 1667 * enough for our purposes. 1668 */ 1669 nr_devices = fs_info->fs_devices->open_devices; 1670 if (!nr_devices) { 1671 smp_mb(); 1672 nr_devices = fs_info->fs_devices->open_devices; 1673 ASSERT(nr_devices); 1674 if (!nr_devices) { 1675 *free_bytes = 0; 1676 return 0; 1677 } 1678 } 1679 1680 devices_info = kmalloc_array(nr_devices, sizeof(*devices_info), 1681 GFP_NOFS); 1682 if (!devices_info) 1683 return -ENOMEM; 1684 1685 /* calc min stripe number for data space alloction */ 1686 type = btrfs_get_alloc_profile(root, 1); 1687 if (type & BTRFS_BLOCK_GROUP_RAID0) { 1688 min_stripes = 2; 1689 num_stripes = nr_devices; 1690 } else if (type & BTRFS_BLOCK_GROUP_RAID1) { 1691 min_stripes = 2; 1692 num_stripes = 2; 1693 } else if (type & BTRFS_BLOCK_GROUP_RAID10) { 1694 min_stripes = 4; 1695 num_stripes = 4; 1696 } 1697 1698 if (type & BTRFS_BLOCK_GROUP_DUP) 1699 min_stripe_size = 2 * BTRFS_STRIPE_LEN; 1700 else 1701 min_stripe_size = BTRFS_STRIPE_LEN; 1702 1703 if (fs_info->alloc_start) 1704 mutex_lock(&fs_devices->device_list_mutex); 1705 rcu_read_lock(); 1706 list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) { 1707 if (!device->in_fs_metadata || !device->bdev || 1708 device->is_tgtdev_for_dev_replace) 1709 continue; 1710 1711 if (i >= nr_devices) 1712 break; 1713 1714 avail_space = device->total_bytes - device->bytes_used; 1715 1716 /* align with stripe_len */ 1717 do_div(avail_space, BTRFS_STRIPE_LEN); 1718 avail_space *= BTRFS_STRIPE_LEN; 1719 1720 /* 1721 * In order to avoid overwritting the superblock on the drive, 1722 * btrfs starts at an offset of at least 1MB when doing chunk 1723 * allocation. 1724 */ 1725 skip_space = 1024 * 1024; 1726 1727 /* user can set the offset in fs_info->alloc_start. */ 1728 if (fs_info->alloc_start && 1729 fs_info->alloc_start + BTRFS_STRIPE_LEN <= 1730 device->total_bytes) { 1731 rcu_read_unlock(); 1732 skip_space = max(fs_info->alloc_start, skip_space); 1733 1734 /* 1735 * btrfs can not use the free space in 1736 * [0, skip_space - 1], we must subtract it from the 1737 * total. In order to implement it, we account the used 1738 * space in this range first. 1739 */ 1740 ret = btrfs_account_dev_extents_size(device, 0, 1741 skip_space - 1, 1742 &used_space); 1743 if (ret) { 1744 kfree(devices_info); 1745 mutex_unlock(&fs_devices->device_list_mutex); 1746 return ret; 1747 } 1748 1749 rcu_read_lock(); 1750 1751 /* calc the free space in [0, skip_space - 1] */ 1752 skip_space -= used_space; 1753 } 1754 1755 /* 1756 * we can use the free space in [0, skip_space - 1], subtract 1757 * it from the total. 1758 */ 1759 if (avail_space && avail_space >= skip_space) 1760 avail_space -= skip_space; 1761 else 1762 avail_space = 0; 1763 1764 if (avail_space < min_stripe_size) 1765 continue; 1766 1767 devices_info[i].dev = device; 1768 devices_info[i].max_avail = avail_space; 1769 1770 i++; 1771 } 1772 rcu_read_unlock(); 1773 if (fs_info->alloc_start) 1774 mutex_unlock(&fs_devices->device_list_mutex); 1775 1776 nr_devices = i; 1777 1778 btrfs_descending_sort_devices(devices_info, nr_devices); 1779 1780 i = nr_devices - 1; 1781 avail_space = 0; 1782 while (nr_devices >= min_stripes) { 1783 if (num_stripes > nr_devices) 1784 num_stripes = nr_devices; 1785 1786 if (devices_info[i].max_avail >= min_stripe_size) { 1787 int j; 1788 u64 alloc_size; 1789 1790 avail_space += devices_info[i].max_avail * num_stripes; 1791 alloc_size = devices_info[i].max_avail; 1792 for (j = i + 1 - num_stripes; j <= i; j++) 1793 devices_info[j].max_avail -= alloc_size; 1794 } 1795 i--; 1796 nr_devices--; 1797 } 1798 1799 kfree(devices_info); 1800 *free_bytes = avail_space; 1801 return 0; 1802 } 1803 1804 /* 1805 * Calculate numbers for 'df', pessimistic in case of mixed raid profiles. 1806 * 1807 * If there's a redundant raid level at DATA block groups, use the respective 1808 * multiplier to scale the sizes. 1809 * 1810 * Unused device space usage is based on simulating the chunk allocator 1811 * algorithm that respects the device sizes, order of allocations and the 1812 * 'alloc_start' value, this is a close approximation of the actual use but 1813 * there are other factors that may change the result (like a new metadata 1814 * chunk). 1815 * 1816 * FIXME: not accurate for mixed block groups, total and free/used are ok, 1817 * available appears slightly larger. 1818 */ 1819 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 1820 { 1821 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); 1822 struct btrfs_super_block *disk_super = fs_info->super_copy; 1823 struct list_head *head = &fs_info->space_info; 1824 struct btrfs_space_info *found; 1825 u64 total_used = 0; 1826 u64 total_free_data = 0; 1827 int bits = dentry->d_sb->s_blocksize_bits; 1828 __be32 *fsid = (__be32 *)fs_info->fsid; 1829 unsigned factor = 1; 1830 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; 1831 int ret; 1832 1833 /* 1834 * holding chunk_muext to avoid allocating new chunks, holding 1835 * device_list_mutex to avoid the device being removed 1836 */ 1837 rcu_read_lock(); 1838 list_for_each_entry_rcu(found, head, list) { 1839 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 1840 int i; 1841 1842 total_free_data += found->disk_total - found->disk_used; 1843 total_free_data -= 1844 btrfs_account_ro_block_groups_free_space(found); 1845 1846 for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { 1847 if (!list_empty(&found->block_groups[i])) { 1848 switch (i) { 1849 case BTRFS_RAID_DUP: 1850 case BTRFS_RAID_RAID1: 1851 case BTRFS_RAID_RAID10: 1852 factor = 2; 1853 } 1854 } 1855 } 1856 } 1857 1858 total_used += found->disk_used; 1859 } 1860 1861 rcu_read_unlock(); 1862 1863 buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor); 1864 buf->f_blocks >>= bits; 1865 buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits); 1866 1867 /* Account global block reserve as used, it's in logical size already */ 1868 spin_lock(&block_rsv->lock); 1869 buf->f_bfree -= block_rsv->size >> bits; 1870 spin_unlock(&block_rsv->lock); 1871 1872 buf->f_bavail = div_u64(total_free_data, factor); 1873 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data); 1874 if (ret) 1875 return ret; 1876 buf->f_bavail += div_u64(total_free_data, factor); 1877 buf->f_bavail = buf->f_bavail >> bits; 1878 1879 buf->f_type = BTRFS_SUPER_MAGIC; 1880 buf->f_bsize = dentry->d_sb->s_blocksize; 1881 buf->f_namelen = BTRFS_NAME_LEN; 1882 1883 /* We treat it as constant endianness (it doesn't matter _which_) 1884 because we want the fsid to come out the same whether mounted 1885 on a big-endian or little-endian host */ 1886 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 1887 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 1888 /* Mask in the root object ID too, to disambiguate subvols */ 1889 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; 1890 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; 1891 1892 return 0; 1893 } 1894 1895 static void btrfs_kill_super(struct super_block *sb) 1896 { 1897 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1898 kill_anon_super(sb); 1899 free_fs_info(fs_info); 1900 } 1901 1902 static struct file_system_type btrfs_fs_type = { 1903 .owner = THIS_MODULE, 1904 .name = "btrfs", 1905 .mount = btrfs_mount, 1906 .kill_sb = btrfs_kill_super, 1907 .fs_flags = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA, 1908 }; 1909 MODULE_ALIAS_FS("btrfs"); 1910 1911 /* 1912 * used by btrfsctl to scan devices when no FS is mounted 1913 */ 1914 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 1915 unsigned long arg) 1916 { 1917 struct btrfs_ioctl_vol_args *vol; 1918 struct btrfs_fs_devices *fs_devices; 1919 int ret = -ENOTTY; 1920 1921 if (!capable(CAP_SYS_ADMIN)) 1922 return -EPERM; 1923 1924 vol = memdup_user((void __user *)arg, sizeof(*vol)); 1925 if (IS_ERR(vol)) 1926 return PTR_ERR(vol); 1927 1928 switch (cmd) { 1929 case BTRFS_IOC_SCAN_DEV: 1930 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 1931 &btrfs_fs_type, &fs_devices); 1932 break; 1933 case BTRFS_IOC_DEVICES_READY: 1934 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 1935 &btrfs_fs_type, &fs_devices); 1936 if (ret) 1937 break; 1938 ret = !(fs_devices->num_devices == fs_devices->total_devices); 1939 break; 1940 } 1941 1942 kfree(vol); 1943 return ret; 1944 } 1945 1946 static int btrfs_freeze(struct super_block *sb) 1947 { 1948 struct btrfs_trans_handle *trans; 1949 struct btrfs_root *root = btrfs_sb(sb)->tree_root; 1950 1951 trans = btrfs_attach_transaction_barrier(root); 1952 if (IS_ERR(trans)) { 1953 /* no transaction, don't bother */ 1954 if (PTR_ERR(trans) == -ENOENT) 1955 return 0; 1956 return PTR_ERR(trans); 1957 } 1958 return btrfs_commit_transaction(trans, root); 1959 } 1960 1961 static int btrfs_unfreeze(struct super_block *sb) 1962 { 1963 return 0; 1964 } 1965 1966 static int btrfs_show_devname(struct seq_file *m, struct dentry *root) 1967 { 1968 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); 1969 struct btrfs_fs_devices *cur_devices; 1970 struct btrfs_device *dev, *first_dev = NULL; 1971 struct list_head *head; 1972 struct rcu_string *name; 1973 1974 mutex_lock(&fs_info->fs_devices->device_list_mutex); 1975 cur_devices = fs_info->fs_devices; 1976 while (cur_devices) { 1977 head = &cur_devices->devices; 1978 list_for_each_entry(dev, head, dev_list) { 1979 if (dev->missing) 1980 continue; 1981 if (!dev->name) 1982 continue; 1983 if (!first_dev || dev->devid < first_dev->devid) 1984 first_dev = dev; 1985 } 1986 cur_devices = cur_devices->seed; 1987 } 1988 1989 if (first_dev) { 1990 rcu_read_lock(); 1991 name = rcu_dereference(first_dev->name); 1992 seq_escape(m, name->str, " \t\n\\"); 1993 rcu_read_unlock(); 1994 } else { 1995 WARN_ON(1); 1996 } 1997 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 1998 return 0; 1999 } 2000 2001 static const struct super_operations btrfs_super_ops = { 2002 .drop_inode = btrfs_drop_inode, 2003 .evict_inode = btrfs_evict_inode, 2004 .put_super = btrfs_put_super, 2005 .sync_fs = btrfs_sync_fs, 2006 .show_options = btrfs_show_options, 2007 .show_devname = btrfs_show_devname, 2008 .write_inode = btrfs_write_inode, 2009 .alloc_inode = btrfs_alloc_inode, 2010 .destroy_inode = btrfs_destroy_inode, 2011 .statfs = btrfs_statfs, 2012 .remount_fs = btrfs_remount, 2013 .freeze_fs = btrfs_freeze, 2014 .unfreeze_fs = btrfs_unfreeze, 2015 }; 2016 2017 static const struct file_operations btrfs_ctl_fops = { 2018 .unlocked_ioctl = btrfs_control_ioctl, 2019 .compat_ioctl = btrfs_control_ioctl, 2020 .owner = THIS_MODULE, 2021 .llseek = noop_llseek, 2022 }; 2023 2024 static struct miscdevice btrfs_misc = { 2025 .minor = BTRFS_MINOR, 2026 .name = "btrfs-control", 2027 .fops = &btrfs_ctl_fops 2028 }; 2029 2030 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 2031 MODULE_ALIAS("devname:btrfs-control"); 2032 2033 static int btrfs_interface_init(void) 2034 { 2035 return misc_register(&btrfs_misc); 2036 } 2037 2038 static void btrfs_interface_exit(void) 2039 { 2040 if (misc_deregister(&btrfs_misc) < 0) 2041 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n"); 2042 } 2043 2044 static void btrfs_print_info(void) 2045 { 2046 printk(KERN_INFO "Btrfs loaded" 2047 #ifdef CONFIG_BTRFS_DEBUG 2048 ", debug=on" 2049 #endif 2050 #ifdef CONFIG_BTRFS_ASSERT 2051 ", assert=on" 2052 #endif 2053 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 2054 ", integrity-checker=on" 2055 #endif 2056 "\n"); 2057 } 2058 2059 static int btrfs_run_sanity_tests(void) 2060 { 2061 int ret; 2062 2063 ret = btrfs_init_test_fs(); 2064 if (ret) 2065 return ret; 2066 2067 ret = btrfs_test_free_space_cache(); 2068 if (ret) 2069 goto out; 2070 ret = btrfs_test_extent_buffer_operations(); 2071 if (ret) 2072 goto out; 2073 ret = btrfs_test_extent_io(); 2074 if (ret) 2075 goto out; 2076 ret = btrfs_test_inodes(); 2077 if (ret) 2078 goto out; 2079 ret = btrfs_test_qgroups(); 2080 out: 2081 btrfs_destroy_test_fs(); 2082 return ret; 2083 } 2084 2085 static int __init init_btrfs_fs(void) 2086 { 2087 int err; 2088 2089 err = btrfs_hash_init(); 2090 if (err) 2091 return err; 2092 2093 btrfs_props_init(); 2094 2095 err = btrfs_init_sysfs(); 2096 if (err) 2097 goto free_hash; 2098 2099 btrfs_init_compress(); 2100 2101 err = btrfs_init_cachep(); 2102 if (err) 2103 goto free_compress; 2104 2105 err = extent_io_init(); 2106 if (err) 2107 goto free_cachep; 2108 2109 err = extent_map_init(); 2110 if (err) 2111 goto free_extent_io; 2112 2113 err = ordered_data_init(); 2114 if (err) 2115 goto free_extent_map; 2116 2117 err = btrfs_delayed_inode_init(); 2118 if (err) 2119 goto free_ordered_data; 2120 2121 err = btrfs_auto_defrag_init(); 2122 if (err) 2123 goto free_delayed_inode; 2124 2125 err = btrfs_delayed_ref_init(); 2126 if (err) 2127 goto free_auto_defrag; 2128 2129 err = btrfs_prelim_ref_init(); 2130 if (err) 2131 goto free_delayed_ref; 2132 2133 err = btrfs_end_io_wq_init(); 2134 if (err) 2135 goto free_prelim_ref; 2136 2137 err = btrfs_interface_init(); 2138 if (err) 2139 goto free_end_io_wq; 2140 2141 btrfs_init_lockdep(); 2142 2143 btrfs_print_info(); 2144 2145 err = btrfs_run_sanity_tests(); 2146 if (err) 2147 goto unregister_ioctl; 2148 2149 err = register_filesystem(&btrfs_fs_type); 2150 if (err) 2151 goto unregister_ioctl; 2152 2153 return 0; 2154 2155 unregister_ioctl: 2156 btrfs_interface_exit(); 2157 free_end_io_wq: 2158 btrfs_end_io_wq_exit(); 2159 free_prelim_ref: 2160 btrfs_prelim_ref_exit(); 2161 free_delayed_ref: 2162 btrfs_delayed_ref_exit(); 2163 free_auto_defrag: 2164 btrfs_auto_defrag_exit(); 2165 free_delayed_inode: 2166 btrfs_delayed_inode_exit(); 2167 free_ordered_data: 2168 ordered_data_exit(); 2169 free_extent_map: 2170 extent_map_exit(); 2171 free_extent_io: 2172 extent_io_exit(); 2173 free_cachep: 2174 btrfs_destroy_cachep(); 2175 free_compress: 2176 btrfs_exit_compress(); 2177 btrfs_exit_sysfs(); 2178 free_hash: 2179 btrfs_hash_exit(); 2180 return err; 2181 } 2182 2183 static void __exit exit_btrfs_fs(void) 2184 { 2185 btrfs_destroy_cachep(); 2186 btrfs_delayed_ref_exit(); 2187 btrfs_auto_defrag_exit(); 2188 btrfs_delayed_inode_exit(); 2189 btrfs_prelim_ref_exit(); 2190 ordered_data_exit(); 2191 extent_map_exit(); 2192 extent_io_exit(); 2193 btrfs_interface_exit(); 2194 btrfs_end_io_wq_exit(); 2195 unregister_filesystem(&btrfs_fs_type); 2196 btrfs_exit_sysfs(); 2197 btrfs_cleanup_fs_uuids(); 2198 btrfs_exit_compress(); 2199 btrfs_hash_exit(); 2200 } 2201 2202 late_initcall(init_btrfs_fs); 2203 module_exit(exit_btrfs_fs) 2204 2205 MODULE_LICENSE("GPL"); 2206