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 59 #define CREATE_TRACE_POINTS 60 #include <trace/events/btrfs.h> 61 62 static const struct super_operations btrfs_super_ops; 63 static struct file_system_type btrfs_fs_type; 64 65 static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno, 66 char nbuf[16]) 67 { 68 char *errstr = NULL; 69 70 switch (errno) { 71 case -EIO: 72 errstr = "IO failure"; 73 break; 74 case -ENOMEM: 75 errstr = "Out of memory"; 76 break; 77 case -EROFS: 78 errstr = "Readonly filesystem"; 79 break; 80 case -EEXIST: 81 errstr = "Object already exists"; 82 break; 83 default: 84 if (nbuf) { 85 if (snprintf(nbuf, 16, "error %d", -errno) >= 0) 86 errstr = nbuf; 87 } 88 break; 89 } 90 91 return errstr; 92 } 93 94 static void __save_error_info(struct btrfs_fs_info *fs_info) 95 { 96 /* 97 * today we only save the error info into ram. Long term we'll 98 * also send it down to the disk 99 */ 100 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR; 101 } 102 103 /* NOTE: 104 * We move write_super stuff at umount in order to avoid deadlock 105 * for umount hold all lock. 106 */ 107 static void save_error_info(struct btrfs_fs_info *fs_info) 108 { 109 __save_error_info(fs_info); 110 } 111 112 /* btrfs handle error by forcing the filesystem readonly */ 113 static void btrfs_handle_error(struct btrfs_fs_info *fs_info) 114 { 115 struct super_block *sb = fs_info->sb; 116 117 if (sb->s_flags & MS_RDONLY) 118 return; 119 120 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { 121 sb->s_flags |= MS_RDONLY; 122 printk(KERN_INFO "btrfs is forced readonly\n"); 123 __btrfs_scrub_cancel(fs_info); 124 // WARN_ON(1); 125 } 126 } 127 128 /* 129 * __btrfs_std_error decodes expected errors from the caller and 130 * invokes the approciate error response. 131 */ 132 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, 133 unsigned int line, int errno, const char *fmt, ...) 134 { 135 struct super_block *sb = fs_info->sb; 136 char nbuf[16]; 137 const char *errstr; 138 va_list args; 139 va_start(args, fmt); 140 141 /* 142 * Special case: if the error is EROFS, and we're already 143 * under MS_RDONLY, then it is safe here. 144 */ 145 if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) 146 return; 147 148 errstr = btrfs_decode_error(fs_info, errno, nbuf); 149 if (fmt) { 150 struct va_format vaf = { 151 .fmt = fmt, 152 .va = &args, 153 }; 154 155 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s (%pV)\n", 156 sb->s_id, function, line, errstr, &vaf); 157 } else { 158 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n", 159 sb->s_id, function, line, errstr); 160 } 161 162 /* Don't go through full error handling during mount */ 163 if (sb->s_flags & MS_BORN) { 164 save_error_info(fs_info); 165 btrfs_handle_error(fs_info); 166 } 167 va_end(args); 168 } 169 170 const char *logtypes[] = { 171 "emergency", 172 "alert", 173 "critical", 174 "error", 175 "warning", 176 "notice", 177 "info", 178 "debug", 179 }; 180 181 void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...) 182 { 183 struct super_block *sb = fs_info->sb; 184 char lvl[4]; 185 struct va_format vaf; 186 va_list args; 187 const char *type = logtypes[4]; 188 189 va_start(args, fmt); 190 191 if (fmt[0] == '<' && isdigit(fmt[1]) && fmt[2] == '>') { 192 memcpy(lvl, fmt, 3); 193 lvl[3] = '\0'; 194 fmt += 3; 195 type = logtypes[fmt[1] - '0']; 196 } else 197 *lvl = '\0'; 198 199 vaf.fmt = fmt; 200 vaf.va = &args; 201 printk("%sBTRFS %s (device %s): %pV", lvl, type, sb->s_id, &vaf); 202 } 203 204 /* 205 * We only mark the transaction aborted and then set the file system read-only. 206 * This will prevent new transactions from starting or trying to join this 207 * one. 208 * 209 * This means that error recovery at the call site is limited to freeing 210 * any local memory allocations and passing the error code up without 211 * further cleanup. The transaction should complete as it normally would 212 * in the call path but will return -EIO. 213 * 214 * We'll complete the cleanup in btrfs_end_transaction and 215 * btrfs_commit_transaction. 216 */ 217 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 218 struct btrfs_root *root, const char *function, 219 unsigned int line, int errno) 220 { 221 WARN_ONCE(1, KERN_DEBUG "btrfs: Transaction aborted"); 222 trans->aborted = errno; 223 /* Nothing used. The other threads that have joined this 224 * transaction may be able to continue. */ 225 if (!trans->blocks_used) { 226 btrfs_printk(root->fs_info, "Aborting unused transaction.\n"); 227 return; 228 } 229 trans->transaction->aborted = errno; 230 __btrfs_std_error(root->fs_info, function, line, errno, NULL); 231 } 232 /* 233 * __btrfs_panic decodes unexpected, fatal errors from the caller, 234 * issues an alert, and either panics or BUGs, depending on mount options. 235 */ 236 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, 237 unsigned int line, int errno, const char *fmt, ...) 238 { 239 char nbuf[16]; 240 char *s_id = "<unknown>"; 241 const char *errstr; 242 struct va_format vaf = { .fmt = fmt }; 243 va_list args; 244 245 if (fs_info) 246 s_id = fs_info->sb->s_id; 247 248 va_start(args, fmt); 249 vaf.va = &args; 250 251 errstr = btrfs_decode_error(fs_info, errno, nbuf); 252 if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR) 253 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", 254 s_id, function, line, &vaf, errstr); 255 256 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", 257 s_id, function, line, &vaf, errstr); 258 va_end(args); 259 /* Caller calls BUG() */ 260 } 261 262 static void btrfs_put_super(struct super_block *sb) 263 { 264 (void)close_ctree(btrfs_sb(sb)->tree_root); 265 /* FIXME: need to fix VFS to return error? */ 266 /* AV: return it _where_? ->put_super() can be triggered by any number 267 * of async events, up to and including delivery of SIGKILL to the 268 * last process that kept it busy. Or segfault in the aforementioned 269 * process... Whom would you report that to? 270 */ 271 } 272 273 enum { 274 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, 275 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, 276 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, 277 Opt_compress_type, Opt_compress_force, Opt_compress_force_type, 278 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, 279 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, 280 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache, 281 Opt_no_space_cache, Opt_recovery, Opt_skip_balance, 282 Opt_check_integrity, Opt_check_integrity_including_extent_data, 283 Opt_check_integrity_print_mask, Opt_fatal_errors, 284 Opt_err, 285 }; 286 287 static match_table_t tokens = { 288 {Opt_degraded, "degraded"}, 289 {Opt_subvol, "subvol=%s"}, 290 {Opt_subvolid, "subvolid=%d"}, 291 {Opt_device, "device=%s"}, 292 {Opt_nodatasum, "nodatasum"}, 293 {Opt_nodatacow, "nodatacow"}, 294 {Opt_nobarrier, "nobarrier"}, 295 {Opt_max_inline, "max_inline=%s"}, 296 {Opt_alloc_start, "alloc_start=%s"}, 297 {Opt_thread_pool, "thread_pool=%d"}, 298 {Opt_compress, "compress"}, 299 {Opt_compress_type, "compress=%s"}, 300 {Opt_compress_force, "compress-force"}, 301 {Opt_compress_force_type, "compress-force=%s"}, 302 {Opt_ssd, "ssd"}, 303 {Opt_ssd_spread, "ssd_spread"}, 304 {Opt_nossd, "nossd"}, 305 {Opt_noacl, "noacl"}, 306 {Opt_notreelog, "notreelog"}, 307 {Opt_flushoncommit, "flushoncommit"}, 308 {Opt_ratio, "metadata_ratio=%d"}, 309 {Opt_discard, "discard"}, 310 {Opt_space_cache, "space_cache"}, 311 {Opt_clear_cache, "clear_cache"}, 312 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, 313 {Opt_enospc_debug, "enospc_debug"}, 314 {Opt_subvolrootid, "subvolrootid=%d"}, 315 {Opt_defrag, "autodefrag"}, 316 {Opt_inode_cache, "inode_cache"}, 317 {Opt_no_space_cache, "nospace_cache"}, 318 {Opt_recovery, "recovery"}, 319 {Opt_skip_balance, "skip_balance"}, 320 {Opt_check_integrity, "check_int"}, 321 {Opt_check_integrity_including_extent_data, "check_int_data"}, 322 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"}, 323 {Opt_fatal_errors, "fatal_errors=%s"}, 324 {Opt_err, NULL}, 325 }; 326 327 /* 328 * Regular mount options parser. Everything that is needed only when 329 * reading in a new superblock is parsed here. 330 * XXX JDM: This needs to be cleaned up for remount. 331 */ 332 int btrfs_parse_options(struct btrfs_root *root, char *options) 333 { 334 struct btrfs_fs_info *info = root->fs_info; 335 substring_t args[MAX_OPT_ARGS]; 336 char *p, *num, *orig = NULL; 337 u64 cache_gen; 338 int intarg; 339 int ret = 0; 340 char *compress_type; 341 bool compress_force = false; 342 343 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); 344 if (cache_gen) 345 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 346 347 if (!options) 348 goto out; 349 350 /* 351 * strsep changes the string, duplicate it because parse_options 352 * gets called twice 353 */ 354 options = kstrdup(options, GFP_NOFS); 355 if (!options) 356 return -ENOMEM; 357 358 orig = options; 359 360 while ((p = strsep(&options, ",")) != NULL) { 361 int token; 362 if (!*p) 363 continue; 364 365 token = match_token(p, tokens, args); 366 switch (token) { 367 case Opt_degraded: 368 printk(KERN_INFO "btrfs: allowing degraded mounts\n"); 369 btrfs_set_opt(info->mount_opt, DEGRADED); 370 break; 371 case Opt_subvol: 372 case Opt_subvolid: 373 case Opt_subvolrootid: 374 case Opt_device: 375 /* 376 * These are parsed by btrfs_parse_early_options 377 * and can be happily ignored here. 378 */ 379 break; 380 case Opt_nodatasum: 381 printk(KERN_INFO "btrfs: setting nodatasum\n"); 382 btrfs_set_opt(info->mount_opt, NODATASUM); 383 break; 384 case Opt_nodatacow: 385 printk(KERN_INFO "btrfs: setting nodatacow\n"); 386 btrfs_set_opt(info->mount_opt, NODATACOW); 387 btrfs_set_opt(info->mount_opt, NODATASUM); 388 break; 389 case Opt_compress_force: 390 case Opt_compress_force_type: 391 compress_force = true; 392 case Opt_compress: 393 case Opt_compress_type: 394 if (token == Opt_compress || 395 token == Opt_compress_force || 396 strcmp(args[0].from, "zlib") == 0) { 397 compress_type = "zlib"; 398 info->compress_type = BTRFS_COMPRESS_ZLIB; 399 } else if (strcmp(args[0].from, "lzo") == 0) { 400 compress_type = "lzo"; 401 info->compress_type = BTRFS_COMPRESS_LZO; 402 } else { 403 ret = -EINVAL; 404 goto out; 405 } 406 407 btrfs_set_opt(info->mount_opt, COMPRESS); 408 if (compress_force) { 409 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); 410 pr_info("btrfs: force %s compression\n", 411 compress_type); 412 } else 413 pr_info("btrfs: use %s compression\n", 414 compress_type); 415 break; 416 case Opt_ssd: 417 printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); 418 btrfs_set_opt(info->mount_opt, SSD); 419 break; 420 case Opt_ssd_spread: 421 printk(KERN_INFO "btrfs: use spread ssd " 422 "allocation scheme\n"); 423 btrfs_set_opt(info->mount_opt, SSD); 424 btrfs_set_opt(info->mount_opt, SSD_SPREAD); 425 break; 426 case Opt_nossd: 427 printk(KERN_INFO "btrfs: not using ssd allocation " 428 "scheme\n"); 429 btrfs_set_opt(info->mount_opt, NOSSD); 430 btrfs_clear_opt(info->mount_opt, SSD); 431 btrfs_clear_opt(info->mount_opt, SSD_SPREAD); 432 break; 433 case Opt_nobarrier: 434 printk(KERN_INFO "btrfs: turning off barriers\n"); 435 btrfs_set_opt(info->mount_opt, NOBARRIER); 436 break; 437 case Opt_thread_pool: 438 intarg = 0; 439 match_int(&args[0], &intarg); 440 if (intarg) 441 info->thread_pool_size = intarg; 442 break; 443 case Opt_max_inline: 444 num = match_strdup(&args[0]); 445 if (num) { 446 info->max_inline = memparse(num, NULL); 447 kfree(num); 448 449 if (info->max_inline) { 450 info->max_inline = max_t(u64, 451 info->max_inline, 452 root->sectorsize); 453 } 454 printk(KERN_INFO "btrfs: max_inline at %llu\n", 455 (unsigned long long)info->max_inline); 456 } 457 break; 458 case Opt_alloc_start: 459 num = match_strdup(&args[0]); 460 if (num) { 461 info->alloc_start = memparse(num, NULL); 462 kfree(num); 463 printk(KERN_INFO 464 "btrfs: allocations start at %llu\n", 465 (unsigned long long)info->alloc_start); 466 } 467 break; 468 case Opt_noacl: 469 root->fs_info->sb->s_flags &= ~MS_POSIXACL; 470 break; 471 case Opt_notreelog: 472 printk(KERN_INFO "btrfs: disabling tree log\n"); 473 btrfs_set_opt(info->mount_opt, NOTREELOG); 474 break; 475 case Opt_flushoncommit: 476 printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); 477 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); 478 break; 479 case Opt_ratio: 480 intarg = 0; 481 match_int(&args[0], &intarg); 482 if (intarg) { 483 info->metadata_ratio = intarg; 484 printk(KERN_INFO "btrfs: metadata ratio %d\n", 485 info->metadata_ratio); 486 } 487 break; 488 case Opt_discard: 489 btrfs_set_opt(info->mount_opt, DISCARD); 490 break; 491 case Opt_space_cache: 492 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 493 break; 494 case Opt_no_space_cache: 495 printk(KERN_INFO "btrfs: disabling disk space caching\n"); 496 btrfs_clear_opt(info->mount_opt, SPACE_CACHE); 497 break; 498 case Opt_inode_cache: 499 printk(KERN_INFO "btrfs: enabling inode map caching\n"); 500 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE); 501 break; 502 case Opt_clear_cache: 503 printk(KERN_INFO "btrfs: force clearing of disk cache\n"); 504 btrfs_set_opt(info->mount_opt, CLEAR_CACHE); 505 break; 506 case Opt_user_subvol_rm_allowed: 507 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 508 break; 509 case Opt_enospc_debug: 510 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 511 break; 512 case Opt_defrag: 513 printk(KERN_INFO "btrfs: enabling auto defrag"); 514 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG); 515 break; 516 case Opt_recovery: 517 printk(KERN_INFO "btrfs: enabling auto recovery"); 518 btrfs_set_opt(info->mount_opt, RECOVERY); 519 break; 520 case Opt_skip_balance: 521 btrfs_set_opt(info->mount_opt, SKIP_BALANCE); 522 break; 523 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 524 case Opt_check_integrity_including_extent_data: 525 printk(KERN_INFO "btrfs: enabling check integrity" 526 " including extent data\n"); 527 btrfs_set_opt(info->mount_opt, 528 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); 529 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 530 break; 531 case Opt_check_integrity: 532 printk(KERN_INFO "btrfs: enabling check integrity\n"); 533 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 534 break; 535 case Opt_check_integrity_print_mask: 536 intarg = 0; 537 match_int(&args[0], &intarg); 538 if (intarg) { 539 info->check_integrity_print_mask = intarg; 540 printk(KERN_INFO "btrfs:" 541 " check_integrity_print_mask 0x%x\n", 542 info->check_integrity_print_mask); 543 } 544 break; 545 #else 546 case Opt_check_integrity_including_extent_data: 547 case Opt_check_integrity: 548 case Opt_check_integrity_print_mask: 549 printk(KERN_ERR "btrfs: support for check_integrity*" 550 " not compiled in!\n"); 551 ret = -EINVAL; 552 goto out; 553 #endif 554 case Opt_fatal_errors: 555 if (strcmp(args[0].from, "panic") == 0) 556 btrfs_set_opt(info->mount_opt, 557 PANIC_ON_FATAL_ERROR); 558 else if (strcmp(args[0].from, "bug") == 0) 559 btrfs_clear_opt(info->mount_opt, 560 PANIC_ON_FATAL_ERROR); 561 else { 562 ret = -EINVAL; 563 goto out; 564 } 565 break; 566 case Opt_err: 567 printk(KERN_INFO "btrfs: unrecognized mount option " 568 "'%s'\n", p); 569 ret = -EINVAL; 570 goto out; 571 default: 572 break; 573 } 574 } 575 out: 576 if (!ret && btrfs_test_opt(root, SPACE_CACHE)) 577 printk(KERN_INFO "btrfs: disk space caching is enabled\n"); 578 kfree(orig); 579 return ret; 580 } 581 582 /* 583 * Parse mount options that are required early in the mount process. 584 * 585 * All other options will be parsed on much later in the mount process and 586 * only when we need to allocate a new super block. 587 */ 588 static int btrfs_parse_early_options(const char *options, fmode_t flags, 589 void *holder, char **subvol_name, u64 *subvol_objectid, 590 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices) 591 { 592 substring_t args[MAX_OPT_ARGS]; 593 char *device_name, *opts, *orig, *p; 594 int error = 0; 595 int intarg; 596 597 if (!options) 598 return 0; 599 600 /* 601 * strsep changes the string, duplicate it because parse_options 602 * gets called twice 603 */ 604 opts = kstrdup(options, GFP_KERNEL); 605 if (!opts) 606 return -ENOMEM; 607 orig = opts; 608 609 while ((p = strsep(&opts, ",")) != NULL) { 610 int token; 611 if (!*p) 612 continue; 613 614 token = match_token(p, tokens, args); 615 switch (token) { 616 case Opt_subvol: 617 kfree(*subvol_name); 618 *subvol_name = match_strdup(&args[0]); 619 break; 620 case Opt_subvolid: 621 intarg = 0; 622 error = match_int(&args[0], &intarg); 623 if (!error) { 624 /* we want the original fs_tree */ 625 if (!intarg) 626 *subvol_objectid = 627 BTRFS_FS_TREE_OBJECTID; 628 else 629 *subvol_objectid = intarg; 630 } 631 break; 632 case Opt_subvolrootid: 633 intarg = 0; 634 error = match_int(&args[0], &intarg); 635 if (!error) { 636 /* we want the original fs_tree */ 637 if (!intarg) 638 *subvol_rootid = 639 BTRFS_FS_TREE_OBJECTID; 640 else 641 *subvol_rootid = intarg; 642 } 643 break; 644 case Opt_device: 645 device_name = match_strdup(&args[0]); 646 if (!device_name) { 647 error = -ENOMEM; 648 goto out; 649 } 650 error = btrfs_scan_one_device(device_name, 651 flags, holder, fs_devices); 652 kfree(device_name); 653 if (error) 654 goto out; 655 break; 656 default: 657 break; 658 } 659 } 660 661 out: 662 kfree(orig); 663 return error; 664 } 665 666 static struct dentry *get_default_root(struct super_block *sb, 667 u64 subvol_objectid) 668 { 669 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 670 struct btrfs_root *root = fs_info->tree_root; 671 struct btrfs_root *new_root; 672 struct btrfs_dir_item *di; 673 struct btrfs_path *path; 674 struct btrfs_key location; 675 struct inode *inode; 676 u64 dir_id; 677 int new = 0; 678 679 /* 680 * We have a specific subvol we want to mount, just setup location and 681 * go look up the root. 682 */ 683 if (subvol_objectid) { 684 location.objectid = subvol_objectid; 685 location.type = BTRFS_ROOT_ITEM_KEY; 686 location.offset = (u64)-1; 687 goto find_root; 688 } 689 690 path = btrfs_alloc_path(); 691 if (!path) 692 return ERR_PTR(-ENOMEM); 693 path->leave_spinning = 1; 694 695 /* 696 * Find the "default" dir item which points to the root item that we 697 * will mount by default if we haven't been given a specific subvolume 698 * to mount. 699 */ 700 dir_id = btrfs_super_root_dir(fs_info->super_copy); 701 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 702 if (IS_ERR(di)) { 703 btrfs_free_path(path); 704 return ERR_CAST(di); 705 } 706 if (!di) { 707 /* 708 * Ok the default dir item isn't there. This is weird since 709 * it's always been there, but don't freak out, just try and 710 * mount to root most subvolume. 711 */ 712 btrfs_free_path(path); 713 dir_id = BTRFS_FIRST_FREE_OBJECTID; 714 new_root = fs_info->fs_root; 715 goto setup_root; 716 } 717 718 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 719 btrfs_free_path(path); 720 721 find_root: 722 new_root = btrfs_read_fs_root_no_name(fs_info, &location); 723 if (IS_ERR(new_root)) 724 return ERR_CAST(new_root); 725 726 if (btrfs_root_refs(&new_root->root_item) == 0) 727 return ERR_PTR(-ENOENT); 728 729 dir_id = btrfs_root_dirid(&new_root->root_item); 730 setup_root: 731 location.objectid = dir_id; 732 location.type = BTRFS_INODE_ITEM_KEY; 733 location.offset = 0; 734 735 inode = btrfs_iget(sb, &location, new_root, &new); 736 if (IS_ERR(inode)) 737 return ERR_CAST(inode); 738 739 /* 740 * If we're just mounting the root most subvol put the inode and return 741 * a reference to the dentry. We will have already gotten a reference 742 * to the inode in btrfs_fill_super so we're good to go. 743 */ 744 if (!new && sb->s_root->d_inode == inode) { 745 iput(inode); 746 return dget(sb->s_root); 747 } 748 749 return d_obtain_alias(inode); 750 } 751 752 static int btrfs_fill_super(struct super_block *sb, 753 struct btrfs_fs_devices *fs_devices, 754 void *data, int silent) 755 { 756 struct inode *inode; 757 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 758 struct btrfs_key key; 759 int err; 760 761 sb->s_maxbytes = MAX_LFS_FILESIZE; 762 sb->s_magic = BTRFS_SUPER_MAGIC; 763 sb->s_op = &btrfs_super_ops; 764 sb->s_d_op = &btrfs_dentry_operations; 765 sb->s_export_op = &btrfs_export_ops; 766 sb->s_xattr = btrfs_xattr_handlers; 767 sb->s_time_gran = 1; 768 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 769 sb->s_flags |= MS_POSIXACL; 770 #endif 771 sb->s_flags |= MS_I_VERSION; 772 err = open_ctree(sb, fs_devices, (char *)data); 773 if (err) { 774 printk("btrfs: open_ctree failed\n"); 775 return err; 776 } 777 778 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 779 key.type = BTRFS_INODE_ITEM_KEY; 780 key.offset = 0; 781 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL); 782 if (IS_ERR(inode)) { 783 err = PTR_ERR(inode); 784 goto fail_close; 785 } 786 787 sb->s_root = d_make_root(inode); 788 if (!sb->s_root) { 789 err = -ENOMEM; 790 goto fail_close; 791 } 792 793 save_mount_options(sb, data); 794 cleancache_init_fs(sb); 795 sb->s_flags |= MS_ACTIVE; 796 return 0; 797 798 fail_close: 799 close_ctree(fs_info->tree_root); 800 return err; 801 } 802 803 int btrfs_sync_fs(struct super_block *sb, int wait) 804 { 805 struct btrfs_trans_handle *trans; 806 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 807 struct btrfs_root *root = fs_info->tree_root; 808 int ret; 809 810 trace_btrfs_sync_fs(wait); 811 812 if (!wait) { 813 filemap_flush(fs_info->btree_inode->i_mapping); 814 return 0; 815 } 816 817 btrfs_wait_ordered_extents(root, 0, 0); 818 819 trans = btrfs_start_transaction(root, 0); 820 if (IS_ERR(trans)) 821 return PTR_ERR(trans); 822 ret = btrfs_commit_transaction(trans, root); 823 return ret; 824 } 825 826 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) 827 { 828 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); 829 struct btrfs_root *root = info->tree_root; 830 char *compress_type; 831 832 if (btrfs_test_opt(root, DEGRADED)) 833 seq_puts(seq, ",degraded"); 834 if (btrfs_test_opt(root, NODATASUM)) 835 seq_puts(seq, ",nodatasum"); 836 if (btrfs_test_opt(root, NODATACOW)) 837 seq_puts(seq, ",nodatacow"); 838 if (btrfs_test_opt(root, NOBARRIER)) 839 seq_puts(seq, ",nobarrier"); 840 if (info->max_inline != 8192 * 1024) 841 seq_printf(seq, ",max_inline=%llu", 842 (unsigned long long)info->max_inline); 843 if (info->alloc_start != 0) 844 seq_printf(seq, ",alloc_start=%llu", 845 (unsigned long long)info->alloc_start); 846 if (info->thread_pool_size != min_t(unsigned long, 847 num_online_cpus() + 2, 8)) 848 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 849 if (btrfs_test_opt(root, COMPRESS)) { 850 if (info->compress_type == BTRFS_COMPRESS_ZLIB) 851 compress_type = "zlib"; 852 else 853 compress_type = "lzo"; 854 if (btrfs_test_opt(root, FORCE_COMPRESS)) 855 seq_printf(seq, ",compress-force=%s", compress_type); 856 else 857 seq_printf(seq, ",compress=%s", compress_type); 858 } 859 if (btrfs_test_opt(root, NOSSD)) 860 seq_puts(seq, ",nossd"); 861 if (btrfs_test_opt(root, SSD_SPREAD)) 862 seq_puts(seq, ",ssd_spread"); 863 else if (btrfs_test_opt(root, SSD)) 864 seq_puts(seq, ",ssd"); 865 if (btrfs_test_opt(root, NOTREELOG)) 866 seq_puts(seq, ",notreelog"); 867 if (btrfs_test_opt(root, FLUSHONCOMMIT)) 868 seq_puts(seq, ",flushoncommit"); 869 if (btrfs_test_opt(root, DISCARD)) 870 seq_puts(seq, ",discard"); 871 if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) 872 seq_puts(seq, ",noacl"); 873 if (btrfs_test_opt(root, SPACE_CACHE)) 874 seq_puts(seq, ",space_cache"); 875 else 876 seq_puts(seq, ",nospace_cache"); 877 if (btrfs_test_opt(root, CLEAR_CACHE)) 878 seq_puts(seq, ",clear_cache"); 879 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 880 seq_puts(seq, ",user_subvol_rm_allowed"); 881 if (btrfs_test_opt(root, ENOSPC_DEBUG)) 882 seq_puts(seq, ",enospc_debug"); 883 if (btrfs_test_opt(root, AUTO_DEFRAG)) 884 seq_puts(seq, ",autodefrag"); 885 if (btrfs_test_opt(root, INODE_MAP_CACHE)) 886 seq_puts(seq, ",inode_cache"); 887 if (btrfs_test_opt(root, SKIP_BALANCE)) 888 seq_puts(seq, ",skip_balance"); 889 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR)) 890 seq_puts(seq, ",fatal_errors=panic"); 891 return 0; 892 } 893 894 static int btrfs_test_super(struct super_block *s, void *data) 895 { 896 struct btrfs_fs_info *p = data; 897 struct btrfs_fs_info *fs_info = btrfs_sb(s); 898 899 return fs_info->fs_devices == p->fs_devices; 900 } 901 902 static int btrfs_set_super(struct super_block *s, void *data) 903 { 904 int err = set_anon_super(s, data); 905 if (!err) 906 s->s_fs_info = data; 907 return err; 908 } 909 910 /* 911 * subvolumes are identified by ino 256 912 */ 913 static inline int is_subvolume_inode(struct inode *inode) 914 { 915 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 916 return 1; 917 return 0; 918 } 919 920 /* 921 * This will strip out the subvol=%s argument for an argument string and add 922 * subvolid=0 to make sure we get the actual tree root for path walking to the 923 * subvol we want. 924 */ 925 static char *setup_root_args(char *args) 926 { 927 unsigned len = strlen(args) + 2 + 1; 928 char *src, *dst, *buf; 929 930 /* 931 * We need the same args as before, but with this substitution: 932 * s!subvol=[^,]+!subvolid=0! 933 * 934 * Since the replacement string is up to 2 bytes longer than the 935 * original, allocate strlen(args) + 2 + 1 bytes. 936 */ 937 938 src = strstr(args, "subvol="); 939 /* This shouldn't happen, but just in case.. */ 940 if (!src) 941 return NULL; 942 943 buf = dst = kmalloc(len, GFP_NOFS); 944 if (!buf) 945 return NULL; 946 947 /* 948 * If the subvol= arg is not at the start of the string, 949 * copy whatever precedes it into buf. 950 */ 951 if (src != args) { 952 *src++ = '\0'; 953 strcpy(buf, args); 954 dst += strlen(args); 955 } 956 957 strcpy(dst, "subvolid=0"); 958 dst += strlen("subvolid=0"); 959 960 /* 961 * If there is a "," after the original subvol=... string, 962 * copy that suffix into our buffer. Otherwise, we're done. 963 */ 964 src = strchr(src, ','); 965 if (src) 966 strcpy(dst, src); 967 968 return buf; 969 } 970 971 static struct dentry *mount_subvol(const char *subvol_name, int flags, 972 const char *device_name, char *data) 973 { 974 struct dentry *root; 975 struct vfsmount *mnt; 976 char *newargs; 977 978 newargs = setup_root_args(data); 979 if (!newargs) 980 return ERR_PTR(-ENOMEM); 981 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, 982 newargs); 983 kfree(newargs); 984 if (IS_ERR(mnt)) 985 return ERR_CAST(mnt); 986 987 root = mount_subtree(mnt, subvol_name); 988 989 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) { 990 struct super_block *s = root->d_sb; 991 dput(root); 992 root = ERR_PTR(-EINVAL); 993 deactivate_locked_super(s); 994 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n", 995 subvol_name); 996 } 997 998 return root; 999 } 1000 1001 /* 1002 * Find a superblock for the given device / mount point. 1003 * 1004 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 1005 * for multiple device setup. Make sure to keep it in sync. 1006 */ 1007 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 1008 const char *device_name, void *data) 1009 { 1010 struct block_device *bdev = NULL; 1011 struct super_block *s; 1012 struct dentry *root; 1013 struct btrfs_fs_devices *fs_devices = NULL; 1014 struct btrfs_fs_info *fs_info = NULL; 1015 fmode_t mode = FMODE_READ; 1016 char *subvol_name = NULL; 1017 u64 subvol_objectid = 0; 1018 u64 subvol_rootid = 0; 1019 int error = 0; 1020 1021 if (!(flags & MS_RDONLY)) 1022 mode |= FMODE_WRITE; 1023 1024 error = btrfs_parse_early_options(data, mode, fs_type, 1025 &subvol_name, &subvol_objectid, 1026 &subvol_rootid, &fs_devices); 1027 if (error) { 1028 kfree(subvol_name); 1029 return ERR_PTR(error); 1030 } 1031 1032 if (subvol_name) { 1033 root = mount_subvol(subvol_name, flags, device_name, data); 1034 kfree(subvol_name); 1035 return root; 1036 } 1037 1038 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); 1039 if (error) 1040 return ERR_PTR(error); 1041 1042 /* 1043 * Setup a dummy root and fs_info for test/set super. This is because 1044 * we don't actually fill this stuff out until open_ctree, but we need 1045 * it for searching for existing supers, so this lets us do that and 1046 * then open_ctree will properly initialize everything later. 1047 */ 1048 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); 1049 if (!fs_info) 1050 return ERR_PTR(-ENOMEM); 1051 1052 fs_info->fs_devices = fs_devices; 1053 1054 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1055 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1056 if (!fs_info->super_copy || !fs_info->super_for_commit) { 1057 error = -ENOMEM; 1058 goto error_fs_info; 1059 } 1060 1061 error = btrfs_open_devices(fs_devices, mode, fs_type); 1062 if (error) 1063 goto error_fs_info; 1064 1065 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 1066 error = -EACCES; 1067 goto error_close_devices; 1068 } 1069 1070 bdev = fs_devices->latest_bdev; 1071 s = sget(fs_type, btrfs_test_super, btrfs_set_super, fs_info); 1072 if (IS_ERR(s)) { 1073 error = PTR_ERR(s); 1074 goto error_close_devices; 1075 } 1076 1077 if (s->s_root) { 1078 btrfs_close_devices(fs_devices); 1079 free_fs_info(fs_info); 1080 if ((flags ^ s->s_flags) & MS_RDONLY) 1081 error = -EBUSY; 1082 } else { 1083 char b[BDEVNAME_SIZE]; 1084 1085 s->s_flags = flags | MS_NOSEC; 1086 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); 1087 btrfs_sb(s)->bdev_holder = fs_type; 1088 error = btrfs_fill_super(s, fs_devices, data, 1089 flags & MS_SILENT ? 1 : 0); 1090 } 1091 1092 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error); 1093 if (IS_ERR(root)) 1094 deactivate_locked_super(s); 1095 1096 return root; 1097 1098 error_close_devices: 1099 btrfs_close_devices(fs_devices); 1100 error_fs_info: 1101 free_fs_info(fs_info); 1102 return ERR_PTR(error); 1103 } 1104 1105 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit) 1106 { 1107 spin_lock_irq(&workers->lock); 1108 workers->max_workers = new_limit; 1109 spin_unlock_irq(&workers->lock); 1110 } 1111 1112 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info, 1113 int new_pool_size, int old_pool_size) 1114 { 1115 if (new_pool_size == old_pool_size) 1116 return; 1117 1118 fs_info->thread_pool_size = new_pool_size; 1119 1120 printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n", 1121 old_pool_size, new_pool_size); 1122 1123 btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size); 1124 btrfs_set_max_workers(&fs_info->workers, new_pool_size); 1125 btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size); 1126 btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size); 1127 btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size); 1128 btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size); 1129 btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size); 1130 btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size); 1131 btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size); 1132 btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size); 1133 btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size); 1134 btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size); 1135 btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size); 1136 btrfs_set_max_workers(&fs_info->scrub_workers, new_pool_size); 1137 } 1138 1139 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1140 { 1141 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1142 struct btrfs_root *root = fs_info->tree_root; 1143 unsigned old_flags = sb->s_flags; 1144 unsigned long old_opts = fs_info->mount_opt; 1145 unsigned long old_compress_type = fs_info->compress_type; 1146 u64 old_max_inline = fs_info->max_inline; 1147 u64 old_alloc_start = fs_info->alloc_start; 1148 int old_thread_pool_size = fs_info->thread_pool_size; 1149 unsigned int old_metadata_ratio = fs_info->metadata_ratio; 1150 int ret; 1151 1152 ret = btrfs_parse_options(root, data); 1153 if (ret) { 1154 ret = -EINVAL; 1155 goto restore; 1156 } 1157 1158 btrfs_resize_thread_pool(fs_info, 1159 fs_info->thread_pool_size, old_thread_pool_size); 1160 1161 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1162 return 0; 1163 1164 if (*flags & MS_RDONLY) { 1165 sb->s_flags |= MS_RDONLY; 1166 1167 ret = btrfs_commit_super(root); 1168 if (ret) 1169 goto restore; 1170 } else { 1171 if (fs_info->fs_devices->rw_devices == 0) { 1172 ret = -EACCES; 1173 goto restore; 1174 } 1175 1176 if (btrfs_super_log_root(fs_info->super_copy) != 0) { 1177 ret = -EINVAL; 1178 goto restore; 1179 } 1180 1181 ret = btrfs_cleanup_fs_roots(fs_info); 1182 if (ret) 1183 goto restore; 1184 1185 /* recover relocation */ 1186 ret = btrfs_recover_relocation(root); 1187 if (ret) 1188 goto restore; 1189 1190 ret = btrfs_resume_balance_async(fs_info); 1191 if (ret) 1192 goto restore; 1193 1194 sb->s_flags &= ~MS_RDONLY; 1195 } 1196 1197 return 0; 1198 1199 restore: 1200 /* We've hit an error - don't reset MS_RDONLY */ 1201 if (sb->s_flags & MS_RDONLY) 1202 old_flags |= MS_RDONLY; 1203 sb->s_flags = old_flags; 1204 fs_info->mount_opt = old_opts; 1205 fs_info->compress_type = old_compress_type; 1206 fs_info->max_inline = old_max_inline; 1207 fs_info->alloc_start = old_alloc_start; 1208 btrfs_resize_thread_pool(fs_info, 1209 old_thread_pool_size, fs_info->thread_pool_size); 1210 fs_info->metadata_ratio = old_metadata_ratio; 1211 return ret; 1212 } 1213 1214 /* Used to sort the devices by max_avail(descending sort) */ 1215 static int btrfs_cmp_device_free_bytes(const void *dev_info1, 1216 const void *dev_info2) 1217 { 1218 if (((struct btrfs_device_info *)dev_info1)->max_avail > 1219 ((struct btrfs_device_info *)dev_info2)->max_avail) 1220 return -1; 1221 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 1222 ((struct btrfs_device_info *)dev_info2)->max_avail) 1223 return 1; 1224 else 1225 return 0; 1226 } 1227 1228 /* 1229 * sort the devices by max_avail, in which max free extent size of each device 1230 * is stored.(Descending Sort) 1231 */ 1232 static inline void btrfs_descending_sort_devices( 1233 struct btrfs_device_info *devices, 1234 size_t nr_devices) 1235 { 1236 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1237 btrfs_cmp_device_free_bytes, NULL); 1238 } 1239 1240 /* 1241 * The helper to calc the free space on the devices that can be used to store 1242 * file data. 1243 */ 1244 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) 1245 { 1246 struct btrfs_fs_info *fs_info = root->fs_info; 1247 struct btrfs_device_info *devices_info; 1248 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1249 struct btrfs_device *device; 1250 u64 skip_space; 1251 u64 type; 1252 u64 avail_space; 1253 u64 used_space; 1254 u64 min_stripe_size; 1255 int min_stripes = 1, num_stripes = 1; 1256 int i = 0, nr_devices; 1257 int ret; 1258 1259 nr_devices = fs_info->fs_devices->open_devices; 1260 BUG_ON(!nr_devices); 1261 1262 devices_info = kmalloc(sizeof(*devices_info) * nr_devices, 1263 GFP_NOFS); 1264 if (!devices_info) 1265 return -ENOMEM; 1266 1267 /* calc min stripe number for data space alloction */ 1268 type = btrfs_get_alloc_profile(root, 1); 1269 if (type & BTRFS_BLOCK_GROUP_RAID0) { 1270 min_stripes = 2; 1271 num_stripes = nr_devices; 1272 } else if (type & BTRFS_BLOCK_GROUP_RAID1) { 1273 min_stripes = 2; 1274 num_stripes = 2; 1275 } else if (type & BTRFS_BLOCK_GROUP_RAID10) { 1276 min_stripes = 4; 1277 num_stripes = 4; 1278 } 1279 1280 if (type & BTRFS_BLOCK_GROUP_DUP) 1281 min_stripe_size = 2 * BTRFS_STRIPE_LEN; 1282 else 1283 min_stripe_size = BTRFS_STRIPE_LEN; 1284 1285 list_for_each_entry(device, &fs_devices->devices, dev_list) { 1286 if (!device->in_fs_metadata || !device->bdev) 1287 continue; 1288 1289 avail_space = device->total_bytes - device->bytes_used; 1290 1291 /* align with stripe_len */ 1292 do_div(avail_space, BTRFS_STRIPE_LEN); 1293 avail_space *= BTRFS_STRIPE_LEN; 1294 1295 /* 1296 * In order to avoid overwritting the superblock on the drive, 1297 * btrfs starts at an offset of at least 1MB when doing chunk 1298 * allocation. 1299 */ 1300 skip_space = 1024 * 1024; 1301 1302 /* user can set the offset in fs_info->alloc_start. */ 1303 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <= 1304 device->total_bytes) 1305 skip_space = max(fs_info->alloc_start, skip_space); 1306 1307 /* 1308 * btrfs can not use the free space in [0, skip_space - 1], 1309 * we must subtract it from the total. In order to implement 1310 * it, we account the used space in this range first. 1311 */ 1312 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1, 1313 &used_space); 1314 if (ret) { 1315 kfree(devices_info); 1316 return ret; 1317 } 1318 1319 /* calc the free space in [0, skip_space - 1] */ 1320 skip_space -= used_space; 1321 1322 /* 1323 * we can use the free space in [0, skip_space - 1], subtract 1324 * it from the total. 1325 */ 1326 if (avail_space && avail_space >= skip_space) 1327 avail_space -= skip_space; 1328 else 1329 avail_space = 0; 1330 1331 if (avail_space < min_stripe_size) 1332 continue; 1333 1334 devices_info[i].dev = device; 1335 devices_info[i].max_avail = avail_space; 1336 1337 i++; 1338 } 1339 1340 nr_devices = i; 1341 1342 btrfs_descending_sort_devices(devices_info, nr_devices); 1343 1344 i = nr_devices - 1; 1345 avail_space = 0; 1346 while (nr_devices >= min_stripes) { 1347 if (num_stripes > nr_devices) 1348 num_stripes = nr_devices; 1349 1350 if (devices_info[i].max_avail >= min_stripe_size) { 1351 int j; 1352 u64 alloc_size; 1353 1354 avail_space += devices_info[i].max_avail * num_stripes; 1355 alloc_size = devices_info[i].max_avail; 1356 for (j = i + 1 - num_stripes; j <= i; j++) 1357 devices_info[j].max_avail -= alloc_size; 1358 } 1359 i--; 1360 nr_devices--; 1361 } 1362 1363 kfree(devices_info); 1364 *free_bytes = avail_space; 1365 return 0; 1366 } 1367 1368 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 1369 { 1370 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); 1371 struct btrfs_super_block *disk_super = fs_info->super_copy; 1372 struct list_head *head = &fs_info->space_info; 1373 struct btrfs_space_info *found; 1374 u64 total_used = 0; 1375 u64 total_free_data = 0; 1376 int bits = dentry->d_sb->s_blocksize_bits; 1377 __be32 *fsid = (__be32 *)fs_info->fsid; 1378 int ret; 1379 1380 /* holding chunk_muext to avoid allocating new chunks */ 1381 mutex_lock(&fs_info->chunk_mutex); 1382 rcu_read_lock(); 1383 list_for_each_entry_rcu(found, head, list) { 1384 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 1385 total_free_data += found->disk_total - found->disk_used; 1386 total_free_data -= 1387 btrfs_account_ro_block_groups_free_space(found); 1388 } 1389 1390 total_used += found->disk_used; 1391 } 1392 rcu_read_unlock(); 1393 1394 buf->f_namelen = BTRFS_NAME_LEN; 1395 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; 1396 buf->f_bfree = buf->f_blocks - (total_used >> bits); 1397 buf->f_bsize = dentry->d_sb->s_blocksize; 1398 buf->f_type = BTRFS_SUPER_MAGIC; 1399 buf->f_bavail = total_free_data; 1400 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data); 1401 if (ret) { 1402 mutex_unlock(&fs_info->chunk_mutex); 1403 return ret; 1404 } 1405 buf->f_bavail += total_free_data; 1406 buf->f_bavail = buf->f_bavail >> bits; 1407 mutex_unlock(&fs_info->chunk_mutex); 1408 1409 /* We treat it as constant endianness (it doesn't matter _which_) 1410 because we want the fsid to come out the same whether mounted 1411 on a big-endian or little-endian host */ 1412 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 1413 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 1414 /* Mask in the root object ID too, to disambiguate subvols */ 1415 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; 1416 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; 1417 1418 return 0; 1419 } 1420 1421 static void btrfs_kill_super(struct super_block *sb) 1422 { 1423 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1424 kill_anon_super(sb); 1425 free_fs_info(fs_info); 1426 } 1427 1428 static struct file_system_type btrfs_fs_type = { 1429 .owner = THIS_MODULE, 1430 .name = "btrfs", 1431 .mount = btrfs_mount, 1432 .kill_sb = btrfs_kill_super, 1433 .fs_flags = FS_REQUIRES_DEV, 1434 }; 1435 1436 /* 1437 * used by btrfsctl to scan devices when no FS is mounted 1438 */ 1439 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 1440 unsigned long arg) 1441 { 1442 struct btrfs_ioctl_vol_args *vol; 1443 struct btrfs_fs_devices *fs_devices; 1444 int ret = -ENOTTY; 1445 1446 if (!capable(CAP_SYS_ADMIN)) 1447 return -EPERM; 1448 1449 vol = memdup_user((void __user *)arg, sizeof(*vol)); 1450 if (IS_ERR(vol)) 1451 return PTR_ERR(vol); 1452 1453 switch (cmd) { 1454 case BTRFS_IOC_SCAN_DEV: 1455 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 1456 &btrfs_fs_type, &fs_devices); 1457 break; 1458 } 1459 1460 kfree(vol); 1461 return ret; 1462 } 1463 1464 static int btrfs_freeze(struct super_block *sb) 1465 { 1466 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1467 mutex_lock(&fs_info->transaction_kthread_mutex); 1468 mutex_lock(&fs_info->cleaner_mutex); 1469 return 0; 1470 } 1471 1472 static int btrfs_unfreeze(struct super_block *sb) 1473 { 1474 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1475 mutex_unlock(&fs_info->cleaner_mutex); 1476 mutex_unlock(&fs_info->transaction_kthread_mutex); 1477 return 0; 1478 } 1479 1480 static void btrfs_fs_dirty_inode(struct inode *inode, int flags) 1481 { 1482 int ret; 1483 1484 ret = btrfs_dirty_inode(inode); 1485 if (ret) 1486 printk_ratelimited(KERN_ERR "btrfs: fail to dirty inode %Lu " 1487 "error %d\n", btrfs_ino(inode), ret); 1488 } 1489 1490 static int btrfs_show_devname(struct seq_file *m, struct dentry *root) 1491 { 1492 struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb); 1493 struct btrfs_fs_devices *cur_devices; 1494 struct btrfs_device *dev, *first_dev = NULL; 1495 struct list_head *head; 1496 struct rcu_string *name; 1497 1498 mutex_lock(&fs_info->fs_devices->device_list_mutex); 1499 cur_devices = fs_info->fs_devices; 1500 while (cur_devices) { 1501 head = &cur_devices->devices; 1502 list_for_each_entry(dev, head, dev_list) { 1503 if (!first_dev || dev->devid < first_dev->devid) 1504 first_dev = dev; 1505 } 1506 cur_devices = cur_devices->seed; 1507 } 1508 1509 if (first_dev) { 1510 rcu_read_lock(); 1511 name = rcu_dereference(first_dev->name); 1512 seq_escape(m, name->str, " \t\n\\"); 1513 rcu_read_unlock(); 1514 } else { 1515 WARN_ON(1); 1516 } 1517 mutex_unlock(&fs_info->fs_devices->device_list_mutex); 1518 return 0; 1519 } 1520 1521 static const struct super_operations btrfs_super_ops = { 1522 .drop_inode = btrfs_drop_inode, 1523 .evict_inode = btrfs_evict_inode, 1524 .put_super = btrfs_put_super, 1525 .sync_fs = btrfs_sync_fs, 1526 .show_options = btrfs_show_options, 1527 .show_devname = btrfs_show_devname, 1528 .write_inode = btrfs_write_inode, 1529 .dirty_inode = btrfs_fs_dirty_inode, 1530 .alloc_inode = btrfs_alloc_inode, 1531 .destroy_inode = btrfs_destroy_inode, 1532 .statfs = btrfs_statfs, 1533 .remount_fs = btrfs_remount, 1534 .freeze_fs = btrfs_freeze, 1535 .unfreeze_fs = btrfs_unfreeze, 1536 }; 1537 1538 static const struct file_operations btrfs_ctl_fops = { 1539 .unlocked_ioctl = btrfs_control_ioctl, 1540 .compat_ioctl = btrfs_control_ioctl, 1541 .owner = THIS_MODULE, 1542 .llseek = noop_llseek, 1543 }; 1544 1545 static struct miscdevice btrfs_misc = { 1546 .minor = BTRFS_MINOR, 1547 .name = "btrfs-control", 1548 .fops = &btrfs_ctl_fops 1549 }; 1550 1551 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 1552 MODULE_ALIAS("devname:btrfs-control"); 1553 1554 static int btrfs_interface_init(void) 1555 { 1556 return misc_register(&btrfs_misc); 1557 } 1558 1559 static void btrfs_interface_exit(void) 1560 { 1561 if (misc_deregister(&btrfs_misc) < 0) 1562 printk(KERN_INFO "misc_deregister failed for control device"); 1563 } 1564 1565 static int __init init_btrfs_fs(void) 1566 { 1567 int err; 1568 1569 err = btrfs_init_sysfs(); 1570 if (err) 1571 return err; 1572 1573 btrfs_init_compress(); 1574 1575 err = btrfs_init_cachep(); 1576 if (err) 1577 goto free_compress; 1578 1579 err = extent_io_init(); 1580 if (err) 1581 goto free_cachep; 1582 1583 err = extent_map_init(); 1584 if (err) 1585 goto free_extent_io; 1586 1587 err = btrfs_delayed_inode_init(); 1588 if (err) 1589 goto free_extent_map; 1590 1591 err = btrfs_interface_init(); 1592 if (err) 1593 goto free_delayed_inode; 1594 1595 err = register_filesystem(&btrfs_fs_type); 1596 if (err) 1597 goto unregister_ioctl; 1598 1599 btrfs_init_lockdep(); 1600 1601 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); 1602 return 0; 1603 1604 unregister_ioctl: 1605 btrfs_interface_exit(); 1606 free_delayed_inode: 1607 btrfs_delayed_inode_exit(); 1608 free_extent_map: 1609 extent_map_exit(); 1610 free_extent_io: 1611 extent_io_exit(); 1612 free_cachep: 1613 btrfs_destroy_cachep(); 1614 free_compress: 1615 btrfs_exit_compress(); 1616 btrfs_exit_sysfs(); 1617 return err; 1618 } 1619 1620 static void __exit exit_btrfs_fs(void) 1621 { 1622 btrfs_destroy_cachep(); 1623 btrfs_delayed_inode_exit(); 1624 extent_map_exit(); 1625 extent_io_exit(); 1626 btrfs_interface_exit(); 1627 unregister_filesystem(&btrfs_fs_type); 1628 btrfs_exit_sysfs(); 1629 btrfs_cleanup_fs_uuids(); 1630 btrfs_exit_compress(); 1631 } 1632 1633 module_init(init_btrfs_fs) 1634 module_exit(exit_btrfs_fs) 1635 1636 MODULE_LICENSE("GPL"); 1637