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 "compat.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 "ioctl.h" 51 #include "print-tree.h" 52 #include "xattr.h" 53 #include "volumes.h" 54 #include "version.h" 55 #include "export.h" 56 #include "compression.h" 57 #include "rcu-string.h" 58 #include "dev-replace.h" 59 60 #define CREATE_TRACE_POINTS 61 #include <trace/events/btrfs.h> 62 63 static const struct super_operations btrfs_super_ops; 64 static struct file_system_type btrfs_fs_type; 65 66 static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno, 67 char nbuf[16]) 68 { 69 char *errstr = NULL; 70 71 switch (errno) { 72 case -EIO: 73 errstr = "IO failure"; 74 break; 75 case -ENOMEM: 76 errstr = "Out of memory"; 77 break; 78 case -EROFS: 79 errstr = "Readonly filesystem"; 80 break; 81 case -EEXIST: 82 errstr = "Object already exists"; 83 break; 84 default: 85 if (nbuf) { 86 if (snprintf(nbuf, 16, "error %d", -errno) >= 0) 87 errstr = nbuf; 88 } 89 break; 90 } 91 92 return errstr; 93 } 94 95 static void __save_error_info(struct btrfs_fs_info *fs_info) 96 { 97 /* 98 * today we only save the error info into ram. Long term we'll 99 * also send it down to the disk 100 */ 101 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR; 102 } 103 104 static void save_error_info(struct btrfs_fs_info *fs_info) 105 { 106 __save_error_info(fs_info); 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 (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { 118 sb->s_flags |= MS_RDONLY; 119 printk(KERN_INFO "btrfs is forced readonly\n"); 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 // WARN_ON(1); 131 } 132 } 133 134 #ifdef CONFIG_PRINTK 135 /* 136 * __btrfs_std_error decodes expected errors from the caller and 137 * invokes the approciate error response. 138 */ 139 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, 140 unsigned int line, int errno, const char *fmt, ...) 141 { 142 struct super_block *sb = fs_info->sb; 143 char nbuf[16]; 144 const char *errstr; 145 va_list args; 146 va_start(args, fmt); 147 148 /* 149 * Special case: if the error is EROFS, and we're already 150 * under MS_RDONLY, then it is safe here. 151 */ 152 if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) 153 return; 154 155 errstr = btrfs_decode_error(fs_info, errno, nbuf); 156 if (fmt) { 157 struct va_format vaf = { 158 .fmt = fmt, 159 .va = &args, 160 }; 161 162 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s (%pV)\n", 163 sb->s_id, function, line, errstr, &vaf); 164 } else { 165 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n", 166 sb->s_id, function, line, errstr); 167 } 168 169 /* Don't go through full error handling during mount */ 170 if (sb->s_flags & MS_BORN) { 171 save_error_info(fs_info); 172 btrfs_handle_error(fs_info); 173 } 174 va_end(args); 175 } 176 177 static const char * const logtypes[] = { 178 "emergency", 179 "alert", 180 "critical", 181 "error", 182 "warning", 183 "notice", 184 "info", 185 "debug", 186 }; 187 188 void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...) 189 { 190 struct super_block *sb = fs_info->sb; 191 char lvl[4]; 192 struct va_format vaf; 193 va_list args; 194 const char *type = logtypes[4]; 195 int kern_level; 196 197 va_start(args, fmt); 198 199 kern_level = printk_get_level(fmt); 200 if (kern_level) { 201 size_t size = printk_skip_level(fmt) - fmt; 202 memcpy(lvl, fmt, size); 203 lvl[size] = '\0'; 204 fmt += size; 205 type = logtypes[kern_level - '0']; 206 } else 207 *lvl = '\0'; 208 209 vaf.fmt = fmt; 210 vaf.va = &args; 211 212 printk("%sBTRFS %s (device %s): %pV", lvl, type, sb->s_id, &vaf); 213 214 va_end(args); 215 } 216 217 #else 218 219 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, 220 unsigned int line, int errno, const char *fmt, ...) 221 { 222 struct super_block *sb = fs_info->sb; 223 224 /* 225 * Special case: if the error is EROFS, and we're already 226 * under MS_RDONLY, then it is safe here. 227 */ 228 if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) 229 return; 230 231 /* Don't go through full error handling during mount */ 232 if (sb->s_flags & MS_BORN) { 233 save_error_info(fs_info); 234 btrfs_handle_error(fs_info); 235 } 236 } 237 #endif 238 239 /* 240 * We only mark the transaction aborted and then set the file system read-only. 241 * This will prevent new transactions from starting or trying to join this 242 * one. 243 * 244 * This means that error recovery at the call site is limited to freeing 245 * any local memory allocations and passing the error code up without 246 * further cleanup. The transaction should complete as it normally would 247 * in the call path but will return -EIO. 248 * 249 * We'll complete the cleanup in btrfs_end_transaction and 250 * btrfs_commit_transaction. 251 */ 252 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 253 struct btrfs_root *root, const char *function, 254 unsigned int line, int errno) 255 { 256 WARN_ONCE(1, KERN_DEBUG "btrfs: Transaction aborted\n"); 257 trans->aborted = errno; 258 /* Nothing used. The other threads that have joined this 259 * transaction may be able to continue. */ 260 if (!trans->blocks_used) { 261 char nbuf[16]; 262 const char *errstr; 263 264 errstr = btrfs_decode_error(root->fs_info, errno, nbuf); 265 btrfs_printk(root->fs_info, 266 "%s:%d: Aborting unused transaction(%s).\n", 267 function, line, errstr); 268 return; 269 } 270 trans->transaction->aborted = errno; 271 __btrfs_std_error(root->fs_info, function, line, errno, NULL); 272 } 273 /* 274 * __btrfs_panic decodes unexpected, fatal errors from the caller, 275 * issues an alert, and either panics or BUGs, depending on mount options. 276 */ 277 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, 278 unsigned int line, int errno, const char *fmt, ...) 279 { 280 char nbuf[16]; 281 char *s_id = "<unknown>"; 282 const char *errstr; 283 struct va_format vaf = { .fmt = fmt }; 284 va_list args; 285 286 if (fs_info) 287 s_id = fs_info->sb->s_id; 288 289 va_start(args, fmt); 290 vaf.va = &args; 291 292 errstr = btrfs_decode_error(fs_info, errno, nbuf); 293 if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR) 294 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", 295 s_id, function, line, &vaf, errstr); 296 297 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", 298 s_id, function, line, &vaf, errstr); 299 va_end(args); 300 /* Caller calls BUG() */ 301 } 302 303 static void btrfs_put_super(struct super_block *sb) 304 { 305 (void)close_ctree(btrfs_sb(sb)->tree_root); 306 /* FIXME: need to fix VFS to return error? */ 307 /* AV: return it _where_? ->put_super() can be triggered by any number 308 * of async events, up to and including delivery of SIGKILL to the 309 * last process that kept it busy. Or segfault in the aforementioned 310 * process... Whom would you report that to? 311 */ 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, 325 Opt_err, 326 }; 327 328 static match_table_t tokens = { 329 {Opt_degraded, "degraded"}, 330 {Opt_subvol, "subvol=%s"}, 331 {Opt_subvolid, "subvolid=%d"}, 332 {Opt_device, "device=%s"}, 333 {Opt_nodatasum, "nodatasum"}, 334 {Opt_nodatacow, "nodatacow"}, 335 {Opt_nobarrier, "nobarrier"}, 336 {Opt_max_inline, "max_inline=%s"}, 337 {Opt_alloc_start, "alloc_start=%s"}, 338 {Opt_thread_pool, "thread_pool=%d"}, 339 {Opt_compress, "compress"}, 340 {Opt_compress_type, "compress=%s"}, 341 {Opt_compress_force, "compress-force"}, 342 {Opt_compress_force_type, "compress-force=%s"}, 343 {Opt_ssd, "ssd"}, 344 {Opt_ssd_spread, "ssd_spread"}, 345 {Opt_nossd, "nossd"}, 346 {Opt_noacl, "noacl"}, 347 {Opt_notreelog, "notreelog"}, 348 {Opt_flushoncommit, "flushoncommit"}, 349 {Opt_ratio, "metadata_ratio=%d"}, 350 {Opt_discard, "discard"}, 351 {Opt_space_cache, "space_cache"}, 352 {Opt_clear_cache, "clear_cache"}, 353 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, 354 {Opt_enospc_debug, "enospc_debug"}, 355 {Opt_subvolrootid, "subvolrootid=%d"}, 356 {Opt_defrag, "autodefrag"}, 357 {Opt_inode_cache, "inode_cache"}, 358 {Opt_no_space_cache, "nospace_cache"}, 359 {Opt_recovery, "recovery"}, 360 {Opt_skip_balance, "skip_balance"}, 361 {Opt_check_integrity, "check_int"}, 362 {Opt_check_integrity_including_extent_data, "check_int_data"}, 363 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"}, 364 {Opt_fatal_errors, "fatal_errors=%s"}, 365 {Opt_err, NULL}, 366 }; 367 368 /* 369 * Regular mount options parser. Everything that is needed only when 370 * reading in a new superblock is parsed here. 371 * XXX JDM: This needs to be cleaned up for remount. 372 */ 373 int btrfs_parse_options(struct btrfs_root *root, char *options) 374 { 375 struct btrfs_fs_info *info = root->fs_info; 376 substring_t args[MAX_OPT_ARGS]; 377 char *p, *num, *orig = NULL; 378 u64 cache_gen; 379 int intarg; 380 int ret = 0; 381 char *compress_type; 382 bool compress_force = false; 383 384 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); 385 if (cache_gen) 386 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 387 388 if (!options) 389 goto out; 390 391 /* 392 * strsep changes the string, duplicate it because parse_options 393 * gets called twice 394 */ 395 options = kstrdup(options, GFP_NOFS); 396 if (!options) 397 return -ENOMEM; 398 399 orig = options; 400 401 while ((p = strsep(&options, ",")) != NULL) { 402 int token; 403 if (!*p) 404 continue; 405 406 token = match_token(p, tokens, args); 407 switch (token) { 408 case Opt_degraded: 409 printk(KERN_INFO "btrfs: allowing degraded mounts\n"); 410 btrfs_set_opt(info->mount_opt, DEGRADED); 411 break; 412 case Opt_subvol: 413 case Opt_subvolid: 414 case Opt_subvolrootid: 415 case Opt_device: 416 /* 417 * These are parsed by btrfs_parse_early_options 418 * and can be happily ignored here. 419 */ 420 break; 421 case Opt_nodatasum: 422 printk(KERN_INFO "btrfs: setting nodatasum\n"); 423 btrfs_set_opt(info->mount_opt, NODATASUM); 424 break; 425 case Opt_nodatacow: 426 if (!btrfs_test_opt(root, COMPRESS) || 427 !btrfs_test_opt(root, FORCE_COMPRESS)) { 428 printk(KERN_INFO "btrfs: setting nodatacow, compression disabled\n"); 429 } else { 430 printk(KERN_INFO "btrfs: setting nodatacow\n"); 431 } 432 info->compress_type = BTRFS_COMPRESS_NONE; 433 btrfs_clear_opt(info->mount_opt, COMPRESS); 434 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 435 btrfs_set_opt(info->mount_opt, NODATACOW); 436 btrfs_set_opt(info->mount_opt, NODATASUM); 437 break; 438 case Opt_compress_force: 439 case Opt_compress_force_type: 440 compress_force = true; 441 case Opt_compress: 442 case Opt_compress_type: 443 if (token == Opt_compress || 444 token == Opt_compress_force || 445 strcmp(args[0].from, "zlib") == 0) { 446 compress_type = "zlib"; 447 info->compress_type = BTRFS_COMPRESS_ZLIB; 448 btrfs_set_opt(info->mount_opt, COMPRESS); 449 btrfs_clear_opt(info->mount_opt, NODATACOW); 450 btrfs_clear_opt(info->mount_opt, NODATASUM); 451 } else if (strcmp(args[0].from, "lzo") == 0) { 452 compress_type = "lzo"; 453 info->compress_type = BTRFS_COMPRESS_LZO; 454 btrfs_set_opt(info->mount_opt, COMPRESS); 455 btrfs_clear_opt(info->mount_opt, NODATACOW); 456 btrfs_clear_opt(info->mount_opt, NODATASUM); 457 btrfs_set_fs_incompat(info, COMPRESS_LZO); 458 } else if (strncmp(args[0].from, "no", 2) == 0) { 459 compress_type = "no"; 460 info->compress_type = BTRFS_COMPRESS_NONE; 461 btrfs_clear_opt(info->mount_opt, COMPRESS); 462 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS); 463 compress_force = false; 464 } else { 465 ret = -EINVAL; 466 goto out; 467 } 468 469 if (compress_force) { 470 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); 471 pr_info("btrfs: force %s compression\n", 472 compress_type); 473 } else 474 pr_info("btrfs: use %s compression\n", 475 compress_type); 476 break; 477 case Opt_ssd: 478 printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); 479 btrfs_set_opt(info->mount_opt, SSD); 480 break; 481 case Opt_ssd_spread: 482 printk(KERN_INFO "btrfs: use spread ssd " 483 "allocation scheme\n"); 484 btrfs_set_opt(info->mount_opt, SSD); 485 btrfs_set_opt(info->mount_opt, SSD_SPREAD); 486 break; 487 case Opt_nossd: 488 printk(KERN_INFO "btrfs: not using ssd allocation " 489 "scheme\n"); 490 btrfs_set_opt(info->mount_opt, NOSSD); 491 btrfs_clear_opt(info->mount_opt, SSD); 492 btrfs_clear_opt(info->mount_opt, SSD_SPREAD); 493 break; 494 case Opt_nobarrier: 495 printk(KERN_INFO "btrfs: turning off barriers\n"); 496 btrfs_set_opt(info->mount_opt, NOBARRIER); 497 break; 498 case Opt_thread_pool: 499 intarg = 0; 500 match_int(&args[0], &intarg); 501 if (intarg) 502 info->thread_pool_size = intarg; 503 break; 504 case Opt_max_inline: 505 num = match_strdup(&args[0]); 506 if (num) { 507 info->max_inline = memparse(num, NULL); 508 kfree(num); 509 510 if (info->max_inline) { 511 info->max_inline = max_t(u64, 512 info->max_inline, 513 root->sectorsize); 514 } 515 printk(KERN_INFO "btrfs: max_inline at %llu\n", 516 (unsigned long long)info->max_inline); 517 } 518 break; 519 case Opt_alloc_start: 520 num = match_strdup(&args[0]); 521 if (num) { 522 info->alloc_start = memparse(num, NULL); 523 kfree(num); 524 printk(KERN_INFO 525 "btrfs: allocations start at %llu\n", 526 (unsigned long long)info->alloc_start); 527 } 528 break; 529 case Opt_noacl: 530 root->fs_info->sb->s_flags &= ~MS_POSIXACL; 531 break; 532 case Opt_notreelog: 533 printk(KERN_INFO "btrfs: disabling tree log\n"); 534 btrfs_set_opt(info->mount_opt, NOTREELOG); 535 break; 536 case Opt_flushoncommit: 537 printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); 538 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); 539 break; 540 case Opt_ratio: 541 intarg = 0; 542 match_int(&args[0], &intarg); 543 if (intarg) { 544 info->metadata_ratio = intarg; 545 printk(KERN_INFO "btrfs: metadata ratio %d\n", 546 info->metadata_ratio); 547 } 548 break; 549 case Opt_discard: 550 btrfs_set_opt(info->mount_opt, DISCARD); 551 break; 552 case Opt_space_cache: 553 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 554 break; 555 case Opt_no_space_cache: 556 printk(KERN_INFO "btrfs: disabling disk space caching\n"); 557 btrfs_clear_opt(info->mount_opt, SPACE_CACHE); 558 break; 559 case Opt_inode_cache: 560 printk(KERN_INFO "btrfs: enabling inode map caching\n"); 561 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE); 562 break; 563 case Opt_clear_cache: 564 printk(KERN_INFO "btrfs: force clearing of disk cache\n"); 565 btrfs_set_opt(info->mount_opt, CLEAR_CACHE); 566 break; 567 case Opt_user_subvol_rm_allowed: 568 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 569 break; 570 case Opt_enospc_debug: 571 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 572 break; 573 case Opt_defrag: 574 printk(KERN_INFO "btrfs: enabling auto defrag\n"); 575 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG); 576 break; 577 case Opt_recovery: 578 printk(KERN_INFO "btrfs: enabling auto recovery\n"); 579 btrfs_set_opt(info->mount_opt, RECOVERY); 580 break; 581 case Opt_skip_balance: 582 btrfs_set_opt(info->mount_opt, SKIP_BALANCE); 583 break; 584 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 585 case Opt_check_integrity_including_extent_data: 586 printk(KERN_INFO "btrfs: enabling check integrity" 587 " including extent data\n"); 588 btrfs_set_opt(info->mount_opt, 589 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); 590 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 591 break; 592 case Opt_check_integrity: 593 printk(KERN_INFO "btrfs: enabling check integrity\n"); 594 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 595 break; 596 case Opt_check_integrity_print_mask: 597 intarg = 0; 598 match_int(&args[0], &intarg); 599 if (intarg) { 600 info->check_integrity_print_mask = intarg; 601 printk(KERN_INFO "btrfs:" 602 " check_integrity_print_mask 0x%x\n", 603 info->check_integrity_print_mask); 604 } 605 break; 606 #else 607 case Opt_check_integrity_including_extent_data: 608 case Opt_check_integrity: 609 case Opt_check_integrity_print_mask: 610 printk(KERN_ERR "btrfs: support for check_integrity*" 611 " not compiled in!\n"); 612 ret = -EINVAL; 613 goto out; 614 #endif 615 case Opt_fatal_errors: 616 if (strcmp(args[0].from, "panic") == 0) 617 btrfs_set_opt(info->mount_opt, 618 PANIC_ON_FATAL_ERROR); 619 else if (strcmp(args[0].from, "bug") == 0) 620 btrfs_clear_opt(info->mount_opt, 621 PANIC_ON_FATAL_ERROR); 622 else { 623 ret = -EINVAL; 624 goto out; 625 } 626 break; 627 case Opt_err: 628 printk(KERN_INFO "btrfs: unrecognized mount option " 629 "'%s'\n", p); 630 ret = -EINVAL; 631 goto out; 632 default: 633 break; 634 } 635 } 636 out: 637 if (!ret && btrfs_test_opt(root, SPACE_CACHE)) 638 printk(KERN_INFO "btrfs: disk space caching is enabled\n"); 639 kfree(orig); 640 return ret; 641 } 642 643 /* 644 * Parse mount options that are required early in the mount process. 645 * 646 * All other options will be parsed on much later in the mount process and 647 * only when we need to allocate a new super block. 648 */ 649 static int btrfs_parse_early_options(const char *options, fmode_t flags, 650 void *holder, char **subvol_name, u64 *subvol_objectid, 651 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices) 652 { 653 substring_t args[MAX_OPT_ARGS]; 654 char *device_name, *opts, *orig, *p; 655 int error = 0; 656 int intarg; 657 658 if (!options) 659 return 0; 660 661 /* 662 * strsep changes the string, duplicate it because parse_options 663 * gets called twice 664 */ 665 opts = kstrdup(options, GFP_KERNEL); 666 if (!opts) 667 return -ENOMEM; 668 orig = opts; 669 670 while ((p = strsep(&opts, ",")) != NULL) { 671 int token; 672 if (!*p) 673 continue; 674 675 token = match_token(p, tokens, args); 676 switch (token) { 677 case Opt_subvol: 678 kfree(*subvol_name); 679 *subvol_name = match_strdup(&args[0]); 680 break; 681 case Opt_subvolid: 682 intarg = 0; 683 error = match_int(&args[0], &intarg); 684 if (!error) { 685 /* we want the original fs_tree */ 686 if (!intarg) 687 *subvol_objectid = 688 BTRFS_FS_TREE_OBJECTID; 689 else 690 *subvol_objectid = intarg; 691 } 692 break; 693 case Opt_subvolrootid: 694 intarg = 0; 695 error = match_int(&args[0], &intarg); 696 if (!error) { 697 /* we want the original fs_tree */ 698 if (!intarg) 699 *subvol_rootid = 700 BTRFS_FS_TREE_OBJECTID; 701 else 702 *subvol_rootid = intarg; 703 } 704 break; 705 case Opt_device: 706 device_name = match_strdup(&args[0]); 707 if (!device_name) { 708 error = -ENOMEM; 709 goto out; 710 } 711 error = btrfs_scan_one_device(device_name, 712 flags, holder, fs_devices); 713 kfree(device_name); 714 if (error) 715 goto out; 716 break; 717 default: 718 break; 719 } 720 } 721 722 out: 723 kfree(orig); 724 return error; 725 } 726 727 static struct dentry *get_default_root(struct super_block *sb, 728 u64 subvol_objectid) 729 { 730 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 731 struct btrfs_root *root = fs_info->tree_root; 732 struct btrfs_root *new_root; 733 struct btrfs_dir_item *di; 734 struct btrfs_path *path; 735 struct btrfs_key location; 736 struct inode *inode; 737 u64 dir_id; 738 int new = 0; 739 740 /* 741 * We have a specific subvol we want to mount, just setup location and 742 * go look up the root. 743 */ 744 if (subvol_objectid) { 745 location.objectid = subvol_objectid; 746 location.type = BTRFS_ROOT_ITEM_KEY; 747 location.offset = (u64)-1; 748 goto find_root; 749 } 750 751 path = btrfs_alloc_path(); 752 if (!path) 753 return ERR_PTR(-ENOMEM); 754 path->leave_spinning = 1; 755 756 /* 757 * Find the "default" dir item which points to the root item that we 758 * will mount by default if we haven't been given a specific subvolume 759 * to mount. 760 */ 761 dir_id = btrfs_super_root_dir(fs_info->super_copy); 762 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 763 if (IS_ERR(di)) { 764 btrfs_free_path(path); 765 return ERR_CAST(di); 766 } 767 if (!di) { 768 /* 769 * Ok the default dir item isn't there. This is weird since 770 * it's always been there, but don't freak out, just try and 771 * mount to root most subvolume. 772 */ 773 btrfs_free_path(path); 774 dir_id = BTRFS_FIRST_FREE_OBJECTID; 775 new_root = fs_info->fs_root; 776 goto setup_root; 777 } 778 779 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 780 btrfs_free_path(path); 781 782 find_root: 783 new_root = btrfs_read_fs_root_no_name(fs_info, &location); 784 if (IS_ERR(new_root)) 785 return ERR_CAST(new_root); 786 787 if (btrfs_root_refs(&new_root->root_item) == 0) 788 return ERR_PTR(-ENOENT); 789 790 dir_id = btrfs_root_dirid(&new_root->root_item); 791 setup_root: 792 location.objectid = dir_id; 793 location.type = BTRFS_INODE_ITEM_KEY; 794 location.offset = 0; 795 796 inode = btrfs_iget(sb, &location, new_root, &new); 797 if (IS_ERR(inode)) 798 return ERR_CAST(inode); 799 800 /* 801 * If we're just mounting the root most subvol put the inode and return 802 * a reference to the dentry. We will have already gotten a reference 803 * to the inode in btrfs_fill_super so we're good to go. 804 */ 805 if (!new && sb->s_root->d_inode == inode) { 806 iput(inode); 807 return dget(sb->s_root); 808 } 809 810 return d_obtain_alias(inode); 811 } 812 813 static int btrfs_fill_super(struct super_block *sb, 814 struct btrfs_fs_devices *fs_devices, 815 void *data, int silent) 816 { 817 struct inode *inode; 818 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 819 struct btrfs_key key; 820 int err; 821 822 sb->s_maxbytes = MAX_LFS_FILESIZE; 823 sb->s_magic = BTRFS_SUPER_MAGIC; 824 sb->s_op = &btrfs_super_ops; 825 sb->s_d_op = &btrfs_dentry_operations; 826 sb->s_export_op = &btrfs_export_ops; 827 sb->s_xattr = btrfs_xattr_handlers; 828 sb->s_time_gran = 1; 829 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 830 sb->s_flags |= MS_POSIXACL; 831 #endif 832 sb->s_flags |= MS_I_VERSION; 833 err = open_ctree(sb, fs_devices, (char *)data); 834 if (err) { 835 printk("btrfs: open_ctree failed\n"); 836 return err; 837 } 838 839 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 840 key.type = BTRFS_INODE_ITEM_KEY; 841 key.offset = 0; 842 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL); 843 if (IS_ERR(inode)) { 844 err = PTR_ERR(inode); 845 goto fail_close; 846 } 847 848 sb->s_root = d_make_root(inode); 849 if (!sb->s_root) { 850 err = -ENOMEM; 851 goto fail_close; 852 } 853 854 save_mount_options(sb, data); 855 cleancache_init_fs(sb); 856 sb->s_flags |= MS_ACTIVE; 857 return 0; 858 859 fail_close: 860 close_ctree(fs_info->tree_root); 861 return err; 862 } 863 864 int btrfs_sync_fs(struct super_block *sb, int wait) 865 { 866 struct btrfs_trans_handle *trans; 867 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 868 struct btrfs_root *root = fs_info->tree_root; 869 870 trace_btrfs_sync_fs(wait); 871 872 if (!wait) { 873 filemap_flush(fs_info->btree_inode->i_mapping); 874 return 0; 875 } 876 877 btrfs_wait_ordered_extents(root, 0); 878 879 trans = btrfs_attach_transaction(root); 880 if (IS_ERR(trans)) { 881 /* no transaction, don't bother */ 882 if (PTR_ERR(trans) == -ENOENT) 883 return 0; 884 return PTR_ERR(trans); 885 } 886 return btrfs_commit_transaction(trans, root); 887 } 888 889 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) 890 { 891 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); 892 struct btrfs_root *root = info->tree_root; 893 char *compress_type; 894 895 if (btrfs_test_opt(root, DEGRADED)) 896 seq_puts(seq, ",degraded"); 897 if (btrfs_test_opt(root, NODATASUM)) 898 seq_puts(seq, ",nodatasum"); 899 if (btrfs_test_opt(root, NODATACOW)) 900 seq_puts(seq, ",nodatacow"); 901 if (btrfs_test_opt(root, NOBARRIER)) 902 seq_puts(seq, ",nobarrier"); 903 if (info->max_inline != 8192 * 1024) 904 seq_printf(seq, ",max_inline=%llu", 905 (unsigned long long)info->max_inline); 906 if (info->alloc_start != 0) 907 seq_printf(seq, ",alloc_start=%llu", 908 (unsigned long long)info->alloc_start); 909 if (info->thread_pool_size != min_t(unsigned long, 910 num_online_cpus() + 2, 8)) 911 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 912 if (btrfs_test_opt(root, COMPRESS)) { 913 if (info->compress_type == BTRFS_COMPRESS_ZLIB) 914 compress_type = "zlib"; 915 else 916 compress_type = "lzo"; 917 if (btrfs_test_opt(root, FORCE_COMPRESS)) 918 seq_printf(seq, ",compress-force=%s", compress_type); 919 else 920 seq_printf(seq, ",compress=%s", compress_type); 921 } 922 if (btrfs_test_opt(root, NOSSD)) 923 seq_puts(seq, ",nossd"); 924 if (btrfs_test_opt(root, SSD_SPREAD)) 925 seq_puts(seq, ",ssd_spread"); 926 else if (btrfs_test_opt(root, SSD)) 927 seq_puts(seq, ",ssd"); 928 if (btrfs_test_opt(root, NOTREELOG)) 929 seq_puts(seq, ",notreelog"); 930 if (btrfs_test_opt(root, FLUSHONCOMMIT)) 931 seq_puts(seq, ",flushoncommit"); 932 if (btrfs_test_opt(root, DISCARD)) 933 seq_puts(seq, ",discard"); 934 if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) 935 seq_puts(seq, ",noacl"); 936 if (btrfs_test_opt(root, SPACE_CACHE)) 937 seq_puts(seq, ",space_cache"); 938 else 939 seq_puts(seq, ",nospace_cache"); 940 if (btrfs_test_opt(root, CLEAR_CACHE)) 941 seq_puts(seq, ",clear_cache"); 942 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 943 seq_puts(seq, ",user_subvol_rm_allowed"); 944 if (btrfs_test_opt(root, ENOSPC_DEBUG)) 945 seq_puts(seq, ",enospc_debug"); 946 if (btrfs_test_opt(root, AUTO_DEFRAG)) 947 seq_puts(seq, ",autodefrag"); 948 if (btrfs_test_opt(root, INODE_MAP_CACHE)) 949 seq_puts(seq, ",inode_cache"); 950 if (btrfs_test_opt(root, SKIP_BALANCE)) 951 seq_puts(seq, ",skip_balance"); 952 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR)) 953 seq_puts(seq, ",fatal_errors=panic"); 954 return 0; 955 } 956 957 static int btrfs_test_super(struct super_block *s, void *data) 958 { 959 struct btrfs_fs_info *p = data; 960 struct btrfs_fs_info *fs_info = btrfs_sb(s); 961 962 return fs_info->fs_devices == p->fs_devices; 963 } 964 965 static int btrfs_set_super(struct super_block *s, void *data) 966 { 967 int err = set_anon_super(s, data); 968 if (!err) 969 s->s_fs_info = data; 970 return err; 971 } 972 973 /* 974 * subvolumes are identified by ino 256 975 */ 976 static inline int is_subvolume_inode(struct inode *inode) 977 { 978 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 979 return 1; 980 return 0; 981 } 982 983 /* 984 * This will strip out the subvol=%s argument for an argument string and add 985 * subvolid=0 to make sure we get the actual tree root for path walking to the 986 * subvol we want. 987 */ 988 static char *setup_root_args(char *args) 989 { 990 unsigned len = strlen(args) + 2 + 1; 991 char *src, *dst, *buf; 992 993 /* 994 * We need the same args as before, but with this substitution: 995 * s!subvol=[^,]+!subvolid=0! 996 * 997 * Since the replacement string is up to 2 bytes longer than the 998 * original, allocate strlen(args) + 2 + 1 bytes. 999 */ 1000 1001 src = strstr(args, "subvol="); 1002 /* This shouldn't happen, but just in case.. */ 1003 if (!src) 1004 return NULL; 1005 1006 buf = dst = kmalloc(len, GFP_NOFS); 1007 if (!buf) 1008 return NULL; 1009 1010 /* 1011 * If the subvol= arg is not at the start of the string, 1012 * copy whatever precedes it into buf. 1013 */ 1014 if (src != args) { 1015 *src++ = '\0'; 1016 strcpy(buf, args); 1017 dst += strlen(args); 1018 } 1019 1020 strcpy(dst, "subvolid=0"); 1021 dst += strlen("subvolid=0"); 1022 1023 /* 1024 * If there is a "," after the original subvol=... string, 1025 * copy that suffix into our buffer. Otherwise, we're done. 1026 */ 1027 src = strchr(src, ','); 1028 if (src) 1029 strcpy(dst, src); 1030 1031 return buf; 1032 } 1033 1034 static struct dentry *mount_subvol(const char *subvol_name, int flags, 1035 const char *device_name, char *data) 1036 { 1037 struct dentry *root; 1038 struct vfsmount *mnt; 1039 char *newargs; 1040 1041 newargs = setup_root_args(data); 1042 if (!newargs) 1043 return ERR_PTR(-ENOMEM); 1044 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, 1045 newargs); 1046 kfree(newargs); 1047 if (IS_ERR(mnt)) 1048 return ERR_CAST(mnt); 1049 1050 root = mount_subtree(mnt, subvol_name); 1051 1052 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) { 1053 struct super_block *s = root->d_sb; 1054 dput(root); 1055 root = ERR_PTR(-EINVAL); 1056 deactivate_locked_super(s); 1057 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n", 1058 subvol_name); 1059 } 1060 1061 return root; 1062 } 1063 1064 /* 1065 * Find a superblock for the given device / mount point. 1066 * 1067 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 1068 * for multiple device setup. Make sure to keep it in sync. 1069 */ 1070 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 1071 const char *device_name, void *data) 1072 { 1073 struct block_device *bdev = NULL; 1074 struct super_block *s; 1075 struct dentry *root; 1076 struct btrfs_fs_devices *fs_devices = NULL; 1077 struct btrfs_fs_info *fs_info = NULL; 1078 fmode_t mode = FMODE_READ; 1079 char *subvol_name = NULL; 1080 u64 subvol_objectid = 0; 1081 u64 subvol_rootid = 0; 1082 int error = 0; 1083 1084 if (!(flags & MS_RDONLY)) 1085 mode |= FMODE_WRITE; 1086 1087 error = btrfs_parse_early_options(data, mode, fs_type, 1088 &subvol_name, &subvol_objectid, 1089 &subvol_rootid, &fs_devices); 1090 if (error) { 1091 kfree(subvol_name); 1092 return ERR_PTR(error); 1093 } 1094 1095 if (subvol_name) { 1096 root = mount_subvol(subvol_name, flags, device_name, data); 1097 kfree(subvol_name); 1098 return root; 1099 } 1100 1101 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); 1102 if (error) 1103 return ERR_PTR(error); 1104 1105 /* 1106 * Setup a dummy root and fs_info for test/set super. This is because 1107 * we don't actually fill this stuff out until open_ctree, but we need 1108 * it for searching for existing supers, so this lets us do that and 1109 * then open_ctree will properly initialize everything later. 1110 */ 1111 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); 1112 if (!fs_info) 1113 return ERR_PTR(-ENOMEM); 1114 1115 fs_info->fs_devices = fs_devices; 1116 1117 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1118 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1119 if (!fs_info->super_copy || !fs_info->super_for_commit) { 1120 error = -ENOMEM; 1121 goto error_fs_info; 1122 } 1123 1124 error = btrfs_open_devices(fs_devices, mode, fs_type); 1125 if (error) 1126 goto error_fs_info; 1127 1128 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 1129 error = -EACCES; 1130 goto error_close_devices; 1131 } 1132 1133 bdev = fs_devices->latest_bdev; 1134 s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC, 1135 fs_info); 1136 if (IS_ERR(s)) { 1137 error = PTR_ERR(s); 1138 goto error_close_devices; 1139 } 1140 1141 if (s->s_root) { 1142 btrfs_close_devices(fs_devices); 1143 free_fs_info(fs_info); 1144 if ((flags ^ s->s_flags) & MS_RDONLY) 1145 error = -EBUSY; 1146 } else { 1147 char b[BDEVNAME_SIZE]; 1148 1149 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); 1150 btrfs_sb(s)->bdev_holder = fs_type; 1151 error = btrfs_fill_super(s, fs_devices, data, 1152 flags & MS_SILENT ? 1 : 0); 1153 } 1154 1155 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error); 1156 if (IS_ERR(root)) 1157 deactivate_locked_super(s); 1158 1159 return root; 1160 1161 error_close_devices: 1162 btrfs_close_devices(fs_devices); 1163 error_fs_info: 1164 free_fs_info(fs_info); 1165 return ERR_PTR(error); 1166 } 1167 1168 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit) 1169 { 1170 spin_lock_irq(&workers->lock); 1171 workers->max_workers = new_limit; 1172 spin_unlock_irq(&workers->lock); 1173 } 1174 1175 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, 1176 int new_pool_size, int old_pool_size) 1177 { 1178 if (new_pool_size == old_pool_size) 1179 return; 1180 1181 fs_info->thread_pool_size = new_pool_size; 1182 1183 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n", 1184 old_pool_size, new_pool_size); 1185 1186 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size); 1187 btrfs_set_max_workers(&fs_info->workers, new_pool_size); 1188 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size); 1189 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size); 1190 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size); 1191 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size); 1192 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size); 1193 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size); 1194 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size); 1195 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size); 1196 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size); 1197 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size); 1198 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size); 1199 btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers, 1200 new_pool_size); 1201 } 1202 1203 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1204 { 1205 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1206 struct btrfs_root *root = fs_info->tree_root; 1207 unsigned old_flags = sb->s_flags; 1208 unsigned long old_opts = fs_info->mount_opt; 1209 unsigned long old_compress_type = fs_info->compress_type; 1210 u64 old_max_inline = fs_info->max_inline; 1211 u64 old_alloc_start = fs_info->alloc_start; 1212 int old_thread_pool_size = fs_info->thread_pool_size; 1213 unsigned int old_metadata_ratio = fs_info->metadata_ratio; 1214 int ret; 1215 1216 ret = btrfs_parse_options(root, data); 1217 if (ret) { 1218 ret = -EINVAL; 1219 goto restore; 1220 } 1221 1222 btrfs_resize_thread_pool(fs_info, 1223 fs_info->thread_pool_size, old_thread_pool_size); 1224 1225 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1226 return 0; 1227 1228 if (*flags & MS_RDONLY) { 1229 /* 1230 * this also happens on 'umount -rf' or on shutdown, when 1231 * the filesystem is busy. 1232 */ 1233 sb->s_flags |= MS_RDONLY; 1234 1235 btrfs_dev_replace_suspend_for_unmount(fs_info); 1236 btrfs_scrub_cancel(fs_info); 1237 1238 ret = btrfs_commit_super(root); 1239 if (ret) 1240 goto restore; 1241 } else { 1242 if (fs_info->fs_devices->rw_devices == 0) { 1243 ret = -EACCES; 1244 goto restore; 1245 } 1246 1247 if (fs_info->fs_devices->missing_devices > 1248 fs_info->num_tolerated_disk_barrier_failures && 1249 !(*flags & MS_RDONLY)) { 1250 printk(KERN_WARNING 1251 "Btrfs: too many missing devices, writeable remount is not allowed\n"); 1252 ret = -EACCES; 1253 goto restore; 1254 } 1255 1256 if (btrfs_super_log_root(fs_info->super_copy) != 0) { 1257 ret = -EINVAL; 1258 goto restore; 1259 } 1260 1261 ret = btrfs_cleanup_fs_roots(fs_info); 1262 if (ret) 1263 goto restore; 1264 1265 /* recover relocation */ 1266 ret = btrfs_recover_relocation(root); 1267 if (ret) 1268 goto restore; 1269 1270 ret = btrfs_resume_balance_async(fs_info); 1271 if (ret) 1272 goto restore; 1273 1274 ret = btrfs_resume_dev_replace_async(fs_info); 1275 if (ret) { 1276 pr_warn("btrfs: failed to resume dev_replace\n"); 1277 goto restore; 1278 } 1279 sb->s_flags &= ~MS_RDONLY; 1280 } 1281 1282 return 0; 1283 1284 restore: 1285 /* We've hit an error - don't reset MS_RDONLY */ 1286 if (sb->s_flags & MS_RDONLY) 1287 old_flags |= MS_RDONLY; 1288 sb->s_flags = old_flags; 1289 fs_info->mount_opt = old_opts; 1290 fs_info->compress_type = old_compress_type; 1291 fs_info->max_inline = old_max_inline; 1292 fs_info->alloc_start = old_alloc_start; 1293 btrfs_resize_thread_pool(fs_info, 1294 old_thread_pool_size, fs_info->thread_pool_size); 1295 fs_info->metadata_ratio = old_metadata_ratio; 1296 return ret; 1297 } 1298 1299 /* Used to sort the devices by max_avail(descending sort) */ 1300 static int btrfs_cmp_device_free_bytes(const void *dev_info1, 1301 const void *dev_info2) 1302 { 1303 if (((struct btrfs_device_info *)dev_info1)->max_avail > 1304 ((struct btrfs_device_info *)dev_info2)->max_avail) 1305 return -1; 1306 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 1307 ((struct btrfs_device_info *)dev_info2)->max_avail) 1308 return 1; 1309 else 1310 return 0; 1311 } 1312 1313 /* 1314 * sort the devices by max_avail, in which max free extent size of each device 1315 * is stored.(Descending Sort) 1316 */ 1317 static inline void btrfs_descending_sort_devices( 1318 struct btrfs_device_info *devices, 1319 size_t nr_devices) 1320 { 1321 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1322 btrfs_cmp_device_free_bytes, NULL); 1323 } 1324 1325 /* 1326 * The helper to calc the free space on the devices that can be used to store 1327 * file data. 1328 */ 1329 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) 1330 { 1331 struct btrfs_fs_info *fs_info = root->fs_info; 1332 struct btrfs_device_info *devices_info; 1333 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1334 struct btrfs_device *device; 1335 u64 skip_space; 1336 u64 type; 1337 u64 avail_space; 1338 u64 used_space; 1339 u64 min_stripe_size; 1340 int min_stripes = 1, num_stripes = 1; 1341 int i = 0, nr_devices; 1342 int ret; 1343 1344 nr_devices = fs_info->fs_devices->open_devices; 1345 BUG_ON(!nr_devices); 1346 1347 devices_info = kmalloc(sizeof(*devices_info) * nr_devices, 1348 GFP_NOFS); 1349 if (!devices_info) 1350 return -ENOMEM; 1351 1352 /* calc min stripe number for data space alloction */ 1353 type = btrfs_get_alloc_profile(root, 1); 1354 if (type & BTRFS_BLOCK_GROUP_RAID0) { 1355 min_stripes = 2; 1356 num_stripes = nr_devices; 1357 } else if (type & BTRFS_BLOCK_GROUP_RAID1) { 1358 min_stripes = 2; 1359 num_stripes = 2; 1360 } else if (type & BTRFS_BLOCK_GROUP_RAID10) { 1361 min_stripes = 4; 1362 num_stripes = 4; 1363 } 1364 1365 if (type & BTRFS_BLOCK_GROUP_DUP) 1366 min_stripe_size = 2 * BTRFS_STRIPE_LEN; 1367 else 1368 min_stripe_size = BTRFS_STRIPE_LEN; 1369 1370 list_for_each_entry(device, &fs_devices->devices, dev_list) { 1371 if (!device->in_fs_metadata || !device->bdev || 1372 device->is_tgtdev_for_dev_replace) 1373 continue; 1374 1375 avail_space = device->total_bytes - device->bytes_used; 1376 1377 /* align with stripe_len */ 1378 do_div(avail_space, BTRFS_STRIPE_LEN); 1379 avail_space *= BTRFS_STRIPE_LEN; 1380 1381 /* 1382 * In order to avoid overwritting the superblock on the drive, 1383 * btrfs starts at an offset of at least 1MB when doing chunk 1384 * allocation. 1385 */ 1386 skip_space = 1024 * 1024; 1387 1388 /* user can set the offset in fs_info->alloc_start. */ 1389 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <= 1390 device->total_bytes) 1391 skip_space = max(fs_info->alloc_start, skip_space); 1392 1393 /* 1394 * btrfs can not use the free space in [0, skip_space - 1], 1395 * we must subtract it from the total. In order to implement 1396 * it, we account the used space in this range first. 1397 */ 1398 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1, 1399 &used_space); 1400 if (ret) { 1401 kfree(devices_info); 1402 return ret; 1403 } 1404 1405 /* calc the free space in [0, skip_space - 1] */ 1406 skip_space -= used_space; 1407 1408 /* 1409 * we can use the free space in [0, skip_space - 1], subtract 1410 * it from the total. 1411 */ 1412 if (avail_space && avail_space >= skip_space) 1413 avail_space -= skip_space; 1414 else 1415 avail_space = 0; 1416 1417 if (avail_space < min_stripe_size) 1418 continue; 1419 1420 devices_info[i].dev = device; 1421 devices_info[i].max_avail = avail_space; 1422 1423 i++; 1424 } 1425 1426 nr_devices = i; 1427 1428 btrfs_descending_sort_devices(devices_info, nr_devices); 1429 1430 i = nr_devices - 1; 1431 avail_space = 0; 1432 while (nr_devices >= min_stripes) { 1433 if (num_stripes > nr_devices) 1434 num_stripes = nr_devices; 1435 1436 if (devices_info[i].max_avail >= min_stripe_size) { 1437 int j; 1438 u64 alloc_size; 1439 1440 avail_space += devices_info[i].max_avail * num_stripes; 1441 alloc_size = devices_info[i].max_avail; 1442 for (j = i + 1 - num_stripes; j <= i; j++) 1443 devices_info[j].max_avail -= alloc_size; 1444 } 1445 i--; 1446 nr_devices--; 1447 } 1448 1449 kfree(devices_info); 1450 *free_bytes = avail_space; 1451 return 0; 1452 } 1453 1454 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 1455 { 1456 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); 1457 struct btrfs_super_block *disk_super = fs_info->super_copy; 1458 struct list_head *head = &fs_info->space_info; 1459 struct btrfs_space_info *found; 1460 u64 total_used = 0; 1461 u64 total_free_data = 0; 1462 int bits = dentry->d_sb->s_blocksize_bits; 1463 __be32 *fsid = (__be32 *)fs_info->fsid; 1464 int ret; 1465 1466 /* holding chunk_muext to avoid allocating new chunks */ 1467 mutex_lock(&fs_info->chunk_mutex); 1468 rcu_read_lock(); 1469 list_for_each_entry_rcu(found, head, list) { 1470 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 1471 total_free_data += found->disk_total - found->disk_used; 1472 total_free_data -= 1473 btrfs_account_ro_block_groups_free_space(found); 1474 } 1475 1476 total_used += found->disk_used; 1477 } 1478 rcu_read_unlock(); 1479 1480 buf->f_namelen = BTRFS_NAME_LEN; 1481 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; 1482 buf->f_bfree = buf->f_blocks - (total_used >> bits); 1483 buf->f_bsize = dentry->d_sb->s_blocksize; 1484 buf->f_type = BTRFS_SUPER_MAGIC; 1485 buf->f_bavail = total_free_data; 1486 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data); 1487 if (ret) { 1488 mutex_unlock(&fs_info->chunk_mutex); 1489 return ret; 1490 } 1491 buf->f_bavail += total_free_data; 1492 buf->f_bavail = buf->f_bavail >> bits; 1493 mutex_unlock(&fs_info->chunk_mutex); 1494 1495 /* We treat it as constant endianness (it doesn't matter _which_) 1496 because we want the fsid to come out the same whether mounted 1497 on a big-endian or little-endian host */ 1498 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 1499 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 1500 /* Mask in the root object ID too, to disambiguate subvols */ 1501 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; 1502 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; 1503 1504 return 0; 1505 } 1506 1507 static void btrfs_kill_super(struct super_block *sb) 1508 { 1509 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1510 kill_anon_super(sb); 1511 free_fs_info(fs_info); 1512 } 1513 1514 static struct file_system_type btrfs_fs_type = { 1515 .owner = THIS_MODULE, 1516 .name = "btrfs", 1517 .mount = btrfs_mount, 1518 .kill_sb = btrfs_kill_super, 1519 .fs_flags = FS_REQUIRES_DEV, 1520 }; 1521 1522 /* 1523 * used by btrfsctl to scan devices when no FS is mounted 1524 */ 1525 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 1526 unsigned long arg) 1527 { 1528 struct btrfs_ioctl_vol_args *vol; 1529 struct btrfs_fs_devices *fs_devices; 1530 int ret = -ENOTTY; 1531 1532 if (!capable(CAP_SYS_ADMIN)) 1533 return -EPERM; 1534 1535 vol = memdup_user((void __user *)arg, sizeof(*vol)); 1536 if (IS_ERR(vol)) 1537 return PTR_ERR(vol); 1538 1539 switch (cmd) { 1540 case BTRFS_IOC_SCAN_DEV: 1541 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 1542 &btrfs_fs_type, &fs_devices); 1543 break; 1544 case BTRFS_IOC_DEVICES_READY: 1545 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 1546 &btrfs_fs_type, &fs_devices); 1547 if (ret) 1548 break; 1549 ret = !(fs_devices->num_devices == fs_devices->total_devices); 1550 break; 1551 } 1552 1553 kfree(vol); 1554 return ret; 1555 } 1556 1557 static int btrfs_freeze(struct super_block *sb) 1558 { 1559 struct btrfs_trans_handle *trans; 1560 struct btrfs_root *root = btrfs_sb(sb)->tree_root; 1561 1562 trans = btrfs_attach_transaction(root); 1563 if (IS_ERR(trans)) { 1564 /* no transaction, don't bother */ 1565 if (PTR_ERR(trans) == -ENOENT) 1566 return 0; 1567 return PTR_ERR(trans); 1568 } 1569 return btrfs_commit_transaction(trans, root); 1570 } 1571 1572 static int btrfs_unfreeze(struct super_block *sb) 1573 { 1574 return 0; 1575 } 1576 1577 static int btrfs_show_devname(struct seq_file *m, struct dentry *root) 1578 { 1579 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); 1580 struct btrfs_fs_devices *cur_devices; 1581 struct btrfs_device *dev, *first_dev = NULL; 1582 struct list_head *head; 1583 struct rcu_string *name; 1584 1585 mutex_lock(&fs_info->fs_devices->device_list_mutex); 1586 cur_devices = fs_info->fs_devices; 1587 while (cur_devices) { 1588 head = &cur_devices->devices; 1589 list_for_each_entry(dev, head, dev_list) { 1590 if (dev->missing) 1591 continue; 1592 if (!first_dev || dev->devid < first_dev->devid) 1593 first_dev = dev; 1594 } 1595 cur_devices = cur_devices->seed; 1596 } 1597 1598 if (first_dev) { 1599 rcu_read_lock(); 1600 name = rcu_dereference(first_dev->name); 1601 seq_escape(m, name->str, " \t\n\\"); 1602 rcu_read_unlock(); 1603 } else { 1604 WARN_ON(1); 1605 } 1606 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 1607 return 0; 1608 } 1609 1610 static const struct super_operations btrfs_super_ops = { 1611 .drop_inode = btrfs_drop_inode, 1612 .evict_inode = btrfs_evict_inode, 1613 .put_super = btrfs_put_super, 1614 .sync_fs = btrfs_sync_fs, 1615 .show_options = btrfs_show_options, 1616 .show_devname = btrfs_show_devname, 1617 .write_inode = btrfs_write_inode, 1618 .alloc_inode = btrfs_alloc_inode, 1619 .destroy_inode = btrfs_destroy_inode, 1620 .statfs = btrfs_statfs, 1621 .remount_fs = btrfs_remount, 1622 .freeze_fs = btrfs_freeze, 1623 .unfreeze_fs = btrfs_unfreeze, 1624 }; 1625 1626 static const struct file_operations btrfs_ctl_fops = { 1627 .unlocked_ioctl = btrfs_control_ioctl, 1628 .compat_ioctl = btrfs_control_ioctl, 1629 .owner = THIS_MODULE, 1630 .llseek = noop_llseek, 1631 }; 1632 1633 static struct miscdevice btrfs_misc = { 1634 .minor = BTRFS_MINOR, 1635 .name = "btrfs-control", 1636 .fops = &btrfs_ctl_fops 1637 }; 1638 1639 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 1640 MODULE_ALIAS("devname:btrfs-control"); 1641 1642 static int btrfs_interface_init(void) 1643 { 1644 return misc_register(&btrfs_misc); 1645 } 1646 1647 static void btrfs_interface_exit(void) 1648 { 1649 if (misc_deregister(&btrfs_misc) < 0) 1650 printk(KERN_INFO "btrfs: misc_deregister failed for control device\n"); 1651 } 1652 1653 static int __init init_btrfs_fs(void) 1654 { 1655 int err; 1656 1657 err = btrfs_init_sysfs(); 1658 if (err) 1659 return err; 1660 1661 btrfs_init_compress(); 1662 1663 err = btrfs_init_cachep(); 1664 if (err) 1665 goto free_compress; 1666 1667 err = extent_io_init(); 1668 if (err) 1669 goto free_cachep; 1670 1671 err = extent_map_init(); 1672 if (err) 1673 goto free_extent_io; 1674 1675 err = ordered_data_init(); 1676 if (err) 1677 goto free_extent_map; 1678 1679 err = btrfs_delayed_inode_init(); 1680 if (err) 1681 goto free_ordered_data; 1682 1683 err = btrfs_auto_defrag_init(); 1684 if (err) 1685 goto free_delayed_inode; 1686 1687 err = btrfs_interface_init(); 1688 if (err) 1689 goto free_auto_defrag; 1690 1691 err = register_filesystem(&btrfs_fs_type); 1692 if (err) 1693 goto unregister_ioctl; 1694 1695 btrfs_init_lockdep(); 1696 1697 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); 1698 return 0; 1699 1700 unregister_ioctl: 1701 btrfs_interface_exit(); 1702 free_auto_defrag: 1703 btrfs_auto_defrag_exit(); 1704 free_delayed_inode: 1705 btrfs_delayed_inode_exit(); 1706 free_ordered_data: 1707 ordered_data_exit(); 1708 free_extent_map: 1709 extent_map_exit(); 1710 free_extent_io: 1711 extent_io_exit(); 1712 free_cachep: 1713 btrfs_destroy_cachep(); 1714 free_compress: 1715 btrfs_exit_compress(); 1716 btrfs_exit_sysfs(); 1717 return err; 1718 } 1719 1720 static void __exit exit_btrfs_fs(void) 1721 { 1722 btrfs_destroy_cachep(); 1723 btrfs_auto_defrag_exit(); 1724 btrfs_delayed_inode_exit(); 1725 ordered_data_exit(); 1726 extent_map_exit(); 1727 extent_io_exit(); 1728 btrfs_interface_exit(); 1729 unregister_filesystem(&btrfs_fs_type); 1730 btrfs_exit_sysfs(); 1731 btrfs_cleanup_fs_uuids(); 1732 btrfs_exit_compress(); 1733 } 1734 1735 module_init(init_btrfs_fs) 1736 module_exit(exit_btrfs_fs) 1737 1738 MODULE_LICENSE("GPL"); 1739