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 58 #define CREATE_TRACE_POINTS 59 #include <trace/events/btrfs.h> 60 61 static const struct super_operations btrfs_super_ops; 62 static struct file_system_type btrfs_fs_type; 63 64 static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno, 65 char nbuf[16]) 66 { 67 char *errstr = NULL; 68 69 switch (errno) { 70 case -EIO: 71 errstr = "IO failure"; 72 break; 73 case -ENOMEM: 74 errstr = "Out of memory"; 75 break; 76 case -EROFS: 77 errstr = "Readonly filesystem"; 78 break; 79 case -EEXIST: 80 errstr = "Object already exists"; 81 break; 82 default: 83 if (nbuf) { 84 if (snprintf(nbuf, 16, "error %d", -errno) >= 0) 85 errstr = nbuf; 86 } 87 break; 88 } 89 90 return errstr; 91 } 92 93 static void __save_error_info(struct btrfs_fs_info *fs_info) 94 { 95 /* 96 * today we only save the error info into ram. Long term we'll 97 * also send it down to the disk 98 */ 99 fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR; 100 } 101 102 /* NOTE: 103 * We move write_super stuff at umount in order to avoid deadlock 104 * for umount hold all lock. 105 */ 106 static void save_error_info(struct btrfs_fs_info *fs_info) 107 { 108 __save_error_info(fs_info); 109 } 110 111 /* btrfs handle error by forcing the filesystem readonly */ 112 static void btrfs_handle_error(struct btrfs_fs_info *fs_info) 113 { 114 struct super_block *sb = fs_info->sb; 115 116 if (sb->s_flags & MS_RDONLY) 117 return; 118 119 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) { 120 sb->s_flags |= MS_RDONLY; 121 printk(KERN_INFO "btrfs is forced readonly\n"); 122 __btrfs_scrub_cancel(fs_info); 123 // WARN_ON(1); 124 } 125 } 126 127 /* 128 * __btrfs_std_error decodes expected errors from the caller and 129 * invokes the approciate error response. 130 */ 131 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function, 132 unsigned int line, int errno, const char *fmt, ...) 133 { 134 struct super_block *sb = fs_info->sb; 135 char nbuf[16]; 136 const char *errstr; 137 va_list args; 138 va_start(args, fmt); 139 140 /* 141 * Special case: if the error is EROFS, and we're already 142 * under MS_RDONLY, then it is safe here. 143 */ 144 if (errno == -EROFS && (sb->s_flags & MS_RDONLY)) 145 return; 146 147 errstr = btrfs_decode_error(fs_info, errno, nbuf); 148 if (fmt) { 149 struct va_format vaf = { 150 .fmt = fmt, 151 .va = &args, 152 }; 153 154 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s (%pV)\n", 155 sb->s_id, function, line, errstr, &vaf); 156 } else { 157 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n", 158 sb->s_id, function, line, errstr); 159 } 160 161 /* Don't go through full error handling during mount */ 162 if (sb->s_flags & MS_BORN) { 163 save_error_info(fs_info); 164 btrfs_handle_error(fs_info); 165 } 166 va_end(args); 167 } 168 169 const char *logtypes[] = { 170 "emergency", 171 "alert", 172 "critical", 173 "error", 174 "warning", 175 "notice", 176 "info", 177 "debug", 178 }; 179 180 void btrfs_printk(struct btrfs_fs_info *fs_info, const char *fmt, ...) 181 { 182 struct super_block *sb = fs_info->sb; 183 char lvl[4]; 184 struct va_format vaf; 185 va_list args; 186 const char *type = logtypes[4]; 187 188 va_start(args, fmt); 189 190 if (fmt[0] == '<' && isdigit(fmt[1]) && fmt[2] == '>') { 191 strncpy(lvl, fmt, 3); 192 fmt += 3; 193 type = logtypes[fmt[1] - '0']; 194 } else 195 *lvl = '\0'; 196 197 vaf.fmt = fmt; 198 vaf.va = &args; 199 printk("%sBTRFS %s (device %s): %pV", lvl, type, sb->s_id, &vaf); 200 } 201 202 /* 203 * We only mark the transaction aborted and then set the file system read-only. 204 * This will prevent new transactions from starting or trying to join this 205 * one. 206 * 207 * This means that error recovery at the call site is limited to freeing 208 * any local memory allocations and passing the error code up without 209 * further cleanup. The transaction should complete as it normally would 210 * in the call path but will return -EIO. 211 * 212 * We'll complete the cleanup in btrfs_end_transaction and 213 * btrfs_commit_transaction. 214 */ 215 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans, 216 struct btrfs_root *root, const char *function, 217 unsigned int line, int errno) 218 { 219 WARN_ONCE(1, KERN_DEBUG "btrfs: Transaction aborted"); 220 trans->aborted = errno; 221 /* Nothing used. The other threads that have joined this 222 * transaction may be able to continue. */ 223 if (!trans->blocks_used) { 224 btrfs_printk(root->fs_info, "Aborting unused transaction.\n"); 225 return; 226 } 227 trans->transaction->aborted = errno; 228 __btrfs_std_error(root->fs_info, function, line, errno, NULL); 229 } 230 /* 231 * __btrfs_panic decodes unexpected, fatal errors from the caller, 232 * issues an alert, and either panics or BUGs, depending on mount options. 233 */ 234 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function, 235 unsigned int line, int errno, const char *fmt, ...) 236 { 237 char nbuf[16]; 238 char *s_id = "<unknown>"; 239 const char *errstr; 240 struct va_format vaf = { .fmt = fmt }; 241 va_list args; 242 243 if (fs_info) 244 s_id = fs_info->sb->s_id; 245 246 va_start(args, fmt); 247 vaf.va = &args; 248 249 errstr = btrfs_decode_error(fs_info, errno, nbuf); 250 if (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR) 251 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", 252 s_id, function, line, &vaf, errstr); 253 254 printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (%s)\n", 255 s_id, function, line, &vaf, errstr); 256 va_end(args); 257 /* Caller calls BUG() */ 258 } 259 260 static void btrfs_put_super(struct super_block *sb) 261 { 262 (void)close_ctree(btrfs_sb(sb)->tree_root); 263 /* FIXME: need to fix VFS to return error? */ 264 /* AV: return it _where_? ->put_super() can be triggered by any number 265 * of async events, up to and including delivery of SIGKILL to the 266 * last process that kept it busy. Or segfault in the aforementioned 267 * process... Whom would you report that to? 268 */ 269 } 270 271 enum { 272 Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum, 273 Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd, 274 Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress, 275 Opt_compress_type, Opt_compress_force, Opt_compress_force_type, 276 Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard, 277 Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed, 278 Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache, 279 Opt_no_space_cache, Opt_recovery, Opt_skip_balance, 280 Opt_check_integrity, Opt_check_integrity_including_extent_data, 281 Opt_check_integrity_print_mask, Opt_fatal_errors, 282 Opt_err, 283 }; 284 285 static match_table_t tokens = { 286 {Opt_degraded, "degraded"}, 287 {Opt_subvol, "subvol=%s"}, 288 {Opt_subvolid, "subvolid=%d"}, 289 {Opt_device, "device=%s"}, 290 {Opt_nodatasum, "nodatasum"}, 291 {Opt_nodatacow, "nodatacow"}, 292 {Opt_nobarrier, "nobarrier"}, 293 {Opt_max_inline, "max_inline=%s"}, 294 {Opt_alloc_start, "alloc_start=%s"}, 295 {Opt_thread_pool, "thread_pool=%d"}, 296 {Opt_compress, "compress"}, 297 {Opt_compress_type, "compress=%s"}, 298 {Opt_compress_force, "compress-force"}, 299 {Opt_compress_force_type, "compress-force=%s"}, 300 {Opt_ssd, "ssd"}, 301 {Opt_ssd_spread, "ssd_spread"}, 302 {Opt_nossd, "nossd"}, 303 {Opt_noacl, "noacl"}, 304 {Opt_notreelog, "notreelog"}, 305 {Opt_flushoncommit, "flushoncommit"}, 306 {Opt_ratio, "metadata_ratio=%d"}, 307 {Opt_discard, "discard"}, 308 {Opt_space_cache, "space_cache"}, 309 {Opt_clear_cache, "clear_cache"}, 310 {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, 311 {Opt_enospc_debug, "enospc_debug"}, 312 {Opt_subvolrootid, "subvolrootid=%d"}, 313 {Opt_defrag, "autodefrag"}, 314 {Opt_inode_cache, "inode_cache"}, 315 {Opt_no_space_cache, "nospace_cache"}, 316 {Opt_recovery, "recovery"}, 317 {Opt_skip_balance, "skip_balance"}, 318 {Opt_check_integrity, "check_int"}, 319 {Opt_check_integrity_including_extent_data, "check_int_data"}, 320 {Opt_check_integrity_print_mask, "check_int_print_mask=%d"}, 321 {Opt_fatal_errors, "fatal_errors=%s"}, 322 {Opt_err, NULL}, 323 }; 324 325 /* 326 * Regular mount options parser. Everything that is needed only when 327 * reading in a new superblock is parsed here. 328 * XXX JDM: This needs to be cleaned up for remount. 329 */ 330 int btrfs_parse_options(struct btrfs_root *root, char *options) 331 { 332 struct btrfs_fs_info *info = root->fs_info; 333 substring_t args[MAX_OPT_ARGS]; 334 char *p, *num, *orig = NULL; 335 u64 cache_gen; 336 int intarg; 337 int ret = 0; 338 char *compress_type; 339 bool compress_force = false; 340 341 cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); 342 if (cache_gen) 343 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 344 345 if (!options) 346 goto out; 347 348 /* 349 * strsep changes the string, duplicate it because parse_options 350 * gets called twice 351 */ 352 options = kstrdup(options, GFP_NOFS); 353 if (!options) 354 return -ENOMEM; 355 356 orig = options; 357 358 while ((p = strsep(&options, ",")) != NULL) { 359 int token; 360 if (!*p) 361 continue; 362 363 token = match_token(p, tokens, args); 364 switch (token) { 365 case Opt_degraded: 366 printk(KERN_INFO "btrfs: allowing degraded mounts\n"); 367 btrfs_set_opt(info->mount_opt, DEGRADED); 368 break; 369 case Opt_subvol: 370 case Opt_subvolid: 371 case Opt_subvolrootid: 372 case Opt_device: 373 /* 374 * These are parsed by btrfs_parse_early_options 375 * and can be happily ignored here. 376 */ 377 break; 378 case Opt_nodatasum: 379 printk(KERN_INFO "btrfs: setting nodatasum\n"); 380 btrfs_set_opt(info->mount_opt, NODATASUM); 381 break; 382 case Opt_nodatacow: 383 printk(KERN_INFO "btrfs: setting nodatacow\n"); 384 btrfs_set_opt(info->mount_opt, NODATACOW); 385 btrfs_set_opt(info->mount_opt, NODATASUM); 386 break; 387 case Opt_compress_force: 388 case Opt_compress_force_type: 389 compress_force = true; 390 case Opt_compress: 391 case Opt_compress_type: 392 if (token == Opt_compress || 393 token == Opt_compress_force || 394 strcmp(args[0].from, "zlib") == 0) { 395 compress_type = "zlib"; 396 info->compress_type = BTRFS_COMPRESS_ZLIB; 397 } else if (strcmp(args[0].from, "lzo") == 0) { 398 compress_type = "lzo"; 399 info->compress_type = BTRFS_COMPRESS_LZO; 400 } else { 401 ret = -EINVAL; 402 goto out; 403 } 404 405 btrfs_set_opt(info->mount_opt, COMPRESS); 406 if (compress_force) { 407 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS); 408 pr_info("btrfs: force %s compression\n", 409 compress_type); 410 } else 411 pr_info("btrfs: use %s compression\n", 412 compress_type); 413 break; 414 case Opt_ssd: 415 printk(KERN_INFO "btrfs: use ssd allocation scheme\n"); 416 btrfs_set_opt(info->mount_opt, SSD); 417 break; 418 case Opt_ssd_spread: 419 printk(KERN_INFO "btrfs: use spread ssd " 420 "allocation scheme\n"); 421 btrfs_set_opt(info->mount_opt, SSD); 422 btrfs_set_opt(info->mount_opt, SSD_SPREAD); 423 break; 424 case Opt_nossd: 425 printk(KERN_INFO "btrfs: not using ssd allocation " 426 "scheme\n"); 427 btrfs_set_opt(info->mount_opt, NOSSD); 428 btrfs_clear_opt(info->mount_opt, SSD); 429 btrfs_clear_opt(info->mount_opt, SSD_SPREAD); 430 break; 431 case Opt_nobarrier: 432 printk(KERN_INFO "btrfs: turning off barriers\n"); 433 btrfs_set_opt(info->mount_opt, NOBARRIER); 434 break; 435 case Opt_thread_pool: 436 intarg = 0; 437 match_int(&args[0], &intarg); 438 if (intarg) { 439 info->thread_pool_size = intarg; 440 printk(KERN_INFO "btrfs: thread pool %d\n", 441 info->thread_pool_size); 442 } 443 break; 444 case Opt_max_inline: 445 num = match_strdup(&args[0]); 446 if (num) { 447 info->max_inline = memparse(num, NULL); 448 kfree(num); 449 450 if (info->max_inline) { 451 info->max_inline = max_t(u64, 452 info->max_inline, 453 root->sectorsize); 454 } 455 printk(KERN_INFO "btrfs: max_inline at %llu\n", 456 (unsigned long long)info->max_inline); 457 } 458 break; 459 case Opt_alloc_start: 460 num = match_strdup(&args[0]); 461 if (num) { 462 info->alloc_start = memparse(num, NULL); 463 kfree(num); 464 printk(KERN_INFO 465 "btrfs: allocations start at %llu\n", 466 (unsigned long long)info->alloc_start); 467 } 468 break; 469 case Opt_noacl: 470 root->fs_info->sb->s_flags &= ~MS_POSIXACL; 471 break; 472 case Opt_notreelog: 473 printk(KERN_INFO "btrfs: disabling tree log\n"); 474 btrfs_set_opt(info->mount_opt, NOTREELOG); 475 break; 476 case Opt_flushoncommit: 477 printk(KERN_INFO "btrfs: turning on flush-on-commit\n"); 478 btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT); 479 break; 480 case Opt_ratio: 481 intarg = 0; 482 match_int(&args[0], &intarg); 483 if (intarg) { 484 info->metadata_ratio = intarg; 485 printk(KERN_INFO "btrfs: metadata ratio %d\n", 486 info->metadata_ratio); 487 } 488 break; 489 case Opt_discard: 490 btrfs_set_opt(info->mount_opt, DISCARD); 491 break; 492 case Opt_space_cache: 493 btrfs_set_opt(info->mount_opt, SPACE_CACHE); 494 break; 495 case Opt_no_space_cache: 496 printk(KERN_INFO "btrfs: disabling disk space caching\n"); 497 btrfs_clear_opt(info->mount_opt, SPACE_CACHE); 498 break; 499 case Opt_inode_cache: 500 printk(KERN_INFO "btrfs: enabling inode map caching\n"); 501 btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE); 502 break; 503 case Opt_clear_cache: 504 printk(KERN_INFO "btrfs: force clearing of disk cache\n"); 505 btrfs_set_opt(info->mount_opt, CLEAR_CACHE); 506 break; 507 case Opt_user_subvol_rm_allowed: 508 btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); 509 break; 510 case Opt_enospc_debug: 511 btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); 512 break; 513 case Opt_defrag: 514 printk(KERN_INFO "btrfs: enabling auto defrag"); 515 btrfs_set_opt(info->mount_opt, AUTO_DEFRAG); 516 break; 517 case Opt_recovery: 518 printk(KERN_INFO "btrfs: enabling auto recovery"); 519 btrfs_set_opt(info->mount_opt, RECOVERY); 520 break; 521 case Opt_skip_balance: 522 btrfs_set_opt(info->mount_opt, SKIP_BALANCE); 523 break; 524 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY 525 case Opt_check_integrity_including_extent_data: 526 printk(KERN_INFO "btrfs: enabling check integrity" 527 " including extent data\n"); 528 btrfs_set_opt(info->mount_opt, 529 CHECK_INTEGRITY_INCLUDING_EXTENT_DATA); 530 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 531 break; 532 case Opt_check_integrity: 533 printk(KERN_INFO "btrfs: enabling check integrity\n"); 534 btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY); 535 break; 536 case Opt_check_integrity_print_mask: 537 intarg = 0; 538 match_int(&args[0], &intarg); 539 if (intarg) { 540 info->check_integrity_print_mask = intarg; 541 printk(KERN_INFO "btrfs:" 542 " check_integrity_print_mask 0x%x\n", 543 info->check_integrity_print_mask); 544 } 545 break; 546 #else 547 case Opt_check_integrity_including_extent_data: 548 case Opt_check_integrity: 549 case Opt_check_integrity_print_mask: 550 printk(KERN_ERR "btrfs: support for check_integrity*" 551 " not compiled in!\n"); 552 ret = -EINVAL; 553 goto out; 554 #endif 555 case Opt_fatal_errors: 556 if (strcmp(args[0].from, "panic") == 0) 557 btrfs_set_opt(info->mount_opt, 558 PANIC_ON_FATAL_ERROR); 559 else if (strcmp(args[0].from, "bug") == 0) 560 btrfs_clear_opt(info->mount_opt, 561 PANIC_ON_FATAL_ERROR); 562 else { 563 ret = -EINVAL; 564 goto out; 565 } 566 break; 567 case Opt_err: 568 printk(KERN_INFO "btrfs: unrecognized mount option " 569 "'%s'\n", p); 570 ret = -EINVAL; 571 goto out; 572 default: 573 break; 574 } 575 } 576 out: 577 if (!ret && btrfs_test_opt(root, SPACE_CACHE)) 578 printk(KERN_INFO "btrfs: disk space caching is enabled\n"); 579 kfree(orig); 580 return ret; 581 } 582 583 /* 584 * Parse mount options that are required early in the mount process. 585 * 586 * All other options will be parsed on much later in the mount process and 587 * only when we need to allocate a new super block. 588 */ 589 static int btrfs_parse_early_options(const char *options, fmode_t flags, 590 void *holder, char **subvol_name, u64 *subvol_objectid, 591 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices) 592 { 593 substring_t args[MAX_OPT_ARGS]; 594 char *device_name, *opts, *orig, *p; 595 int error = 0; 596 int intarg; 597 598 if (!options) 599 return 0; 600 601 /* 602 * strsep changes the string, duplicate it because parse_options 603 * gets called twice 604 */ 605 opts = kstrdup(options, GFP_KERNEL); 606 if (!opts) 607 return -ENOMEM; 608 orig = opts; 609 610 while ((p = strsep(&opts, ",")) != NULL) { 611 int token; 612 if (!*p) 613 continue; 614 615 token = match_token(p, tokens, args); 616 switch (token) { 617 case Opt_subvol: 618 kfree(*subvol_name); 619 *subvol_name = match_strdup(&args[0]); 620 break; 621 case Opt_subvolid: 622 intarg = 0; 623 error = match_int(&args[0], &intarg); 624 if (!error) { 625 /* we want the original fs_tree */ 626 if (!intarg) 627 *subvol_objectid = 628 BTRFS_FS_TREE_OBJECTID; 629 else 630 *subvol_objectid = intarg; 631 } 632 break; 633 case Opt_subvolrootid: 634 intarg = 0; 635 error = match_int(&args[0], &intarg); 636 if (!error) { 637 /* we want the original fs_tree */ 638 if (!intarg) 639 *subvol_rootid = 640 BTRFS_FS_TREE_OBJECTID; 641 else 642 *subvol_rootid = intarg; 643 } 644 break; 645 case Opt_device: 646 device_name = match_strdup(&args[0]); 647 if (!device_name) { 648 error = -ENOMEM; 649 goto out; 650 } 651 error = btrfs_scan_one_device(device_name, 652 flags, holder, fs_devices); 653 kfree(device_name); 654 if (error) 655 goto out; 656 break; 657 default: 658 break; 659 } 660 } 661 662 out: 663 kfree(orig); 664 return error; 665 } 666 667 static struct dentry *get_default_root(struct super_block *sb, 668 u64 subvol_objectid) 669 { 670 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 671 struct btrfs_root *root = fs_info->tree_root; 672 struct btrfs_root *new_root; 673 struct btrfs_dir_item *di; 674 struct btrfs_path *path; 675 struct btrfs_key location; 676 struct inode *inode; 677 u64 dir_id; 678 int new = 0; 679 680 /* 681 * We have a specific subvol we want to mount, just setup location and 682 * go look up the root. 683 */ 684 if (subvol_objectid) { 685 location.objectid = subvol_objectid; 686 location.type = BTRFS_ROOT_ITEM_KEY; 687 location.offset = (u64)-1; 688 goto find_root; 689 } 690 691 path = btrfs_alloc_path(); 692 if (!path) 693 return ERR_PTR(-ENOMEM); 694 path->leave_spinning = 1; 695 696 /* 697 * Find the "default" dir item which points to the root item that we 698 * will mount by default if we haven't been given a specific subvolume 699 * to mount. 700 */ 701 dir_id = btrfs_super_root_dir(fs_info->super_copy); 702 di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0); 703 if (IS_ERR(di)) { 704 btrfs_free_path(path); 705 return ERR_CAST(di); 706 } 707 if (!di) { 708 /* 709 * Ok the default dir item isn't there. This is weird since 710 * it's always been there, but don't freak out, just try and 711 * mount to root most subvolume. 712 */ 713 btrfs_free_path(path); 714 dir_id = BTRFS_FIRST_FREE_OBJECTID; 715 new_root = fs_info->fs_root; 716 goto setup_root; 717 } 718 719 btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location); 720 btrfs_free_path(path); 721 722 find_root: 723 new_root = btrfs_read_fs_root_no_name(fs_info, &location); 724 if (IS_ERR(new_root)) 725 return ERR_CAST(new_root); 726 727 if (btrfs_root_refs(&new_root->root_item) == 0) 728 return ERR_PTR(-ENOENT); 729 730 dir_id = btrfs_root_dirid(&new_root->root_item); 731 setup_root: 732 location.objectid = dir_id; 733 location.type = BTRFS_INODE_ITEM_KEY; 734 location.offset = 0; 735 736 inode = btrfs_iget(sb, &location, new_root, &new); 737 if (IS_ERR(inode)) 738 return ERR_CAST(inode); 739 740 /* 741 * If we're just mounting the root most subvol put the inode and return 742 * a reference to the dentry. We will have already gotten a reference 743 * to the inode in btrfs_fill_super so we're good to go. 744 */ 745 if (!new && sb->s_root->d_inode == inode) { 746 iput(inode); 747 return dget(sb->s_root); 748 } 749 750 return d_obtain_alias(inode); 751 } 752 753 static int btrfs_fill_super(struct super_block *sb, 754 struct btrfs_fs_devices *fs_devices, 755 void *data, int silent) 756 { 757 struct inode *inode; 758 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 759 struct btrfs_key key; 760 int err; 761 762 sb->s_maxbytes = MAX_LFS_FILESIZE; 763 sb->s_magic = BTRFS_SUPER_MAGIC; 764 sb->s_op = &btrfs_super_ops; 765 sb->s_d_op = &btrfs_dentry_operations; 766 sb->s_export_op = &btrfs_export_ops; 767 sb->s_xattr = btrfs_xattr_handlers; 768 sb->s_time_gran = 1; 769 #ifdef CONFIG_BTRFS_FS_POSIX_ACL 770 sb->s_flags |= MS_POSIXACL; 771 #endif 772 773 err = open_ctree(sb, fs_devices, (char *)data); 774 if (err) { 775 printk("btrfs: open_ctree failed\n"); 776 return err; 777 } 778 779 key.objectid = BTRFS_FIRST_FREE_OBJECTID; 780 key.type = BTRFS_INODE_ITEM_KEY; 781 key.offset = 0; 782 inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL); 783 if (IS_ERR(inode)) { 784 err = PTR_ERR(inode); 785 goto fail_close; 786 } 787 788 sb->s_root = d_make_root(inode); 789 if (!sb->s_root) { 790 err = -ENOMEM; 791 goto fail_close; 792 } 793 794 save_mount_options(sb, data); 795 cleancache_init_fs(sb); 796 sb->s_flags |= MS_ACTIVE; 797 return 0; 798 799 fail_close: 800 close_ctree(fs_info->tree_root); 801 return err; 802 } 803 804 int btrfs_sync_fs(struct super_block *sb, int wait) 805 { 806 struct btrfs_trans_handle *trans; 807 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 808 struct btrfs_root *root = fs_info->tree_root; 809 int ret; 810 811 trace_btrfs_sync_fs(wait); 812 813 if (!wait) { 814 filemap_flush(fs_info->btree_inode->i_mapping); 815 return 0; 816 } 817 818 btrfs_start_delalloc_inodes(root, 0); 819 btrfs_wait_ordered_extents(root, 0, 0); 820 821 trans = btrfs_start_transaction(root, 0); 822 if (IS_ERR(trans)) 823 return PTR_ERR(trans); 824 ret = btrfs_commit_transaction(trans, root); 825 return ret; 826 } 827 828 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) 829 { 830 struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb); 831 struct btrfs_root *root = info->tree_root; 832 char *compress_type; 833 834 if (btrfs_test_opt(root, DEGRADED)) 835 seq_puts(seq, ",degraded"); 836 if (btrfs_test_opt(root, NODATASUM)) 837 seq_puts(seq, ",nodatasum"); 838 if (btrfs_test_opt(root, NODATACOW)) 839 seq_puts(seq, ",nodatacow"); 840 if (btrfs_test_opt(root, NOBARRIER)) 841 seq_puts(seq, ",nobarrier"); 842 if (info->max_inline != 8192 * 1024) 843 seq_printf(seq, ",max_inline=%llu", 844 (unsigned long long)info->max_inline); 845 if (info->alloc_start != 0) 846 seq_printf(seq, ",alloc_start=%llu", 847 (unsigned long long)info->alloc_start); 848 if (info->thread_pool_size != min_t(unsigned long, 849 num_online_cpus() + 2, 8)) 850 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size); 851 if (btrfs_test_opt(root, COMPRESS)) { 852 if (info->compress_type == BTRFS_COMPRESS_ZLIB) 853 compress_type = "zlib"; 854 else 855 compress_type = "lzo"; 856 if (btrfs_test_opt(root, FORCE_COMPRESS)) 857 seq_printf(seq, ",compress-force=%s", compress_type); 858 else 859 seq_printf(seq, ",compress=%s", compress_type); 860 } 861 if (btrfs_test_opt(root, NOSSD)) 862 seq_puts(seq, ",nossd"); 863 if (btrfs_test_opt(root, SSD_SPREAD)) 864 seq_puts(seq, ",ssd_spread"); 865 else if (btrfs_test_opt(root, SSD)) 866 seq_puts(seq, ",ssd"); 867 if (btrfs_test_opt(root, NOTREELOG)) 868 seq_puts(seq, ",notreelog"); 869 if (btrfs_test_opt(root, FLUSHONCOMMIT)) 870 seq_puts(seq, ",flushoncommit"); 871 if (btrfs_test_opt(root, DISCARD)) 872 seq_puts(seq, ",discard"); 873 if (!(root->fs_info->sb->s_flags & MS_POSIXACL)) 874 seq_puts(seq, ",noacl"); 875 if (btrfs_test_opt(root, SPACE_CACHE)) 876 seq_puts(seq, ",space_cache"); 877 else 878 seq_puts(seq, ",nospace_cache"); 879 if (btrfs_test_opt(root, CLEAR_CACHE)) 880 seq_puts(seq, ",clear_cache"); 881 if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED)) 882 seq_puts(seq, ",user_subvol_rm_allowed"); 883 if (btrfs_test_opt(root, ENOSPC_DEBUG)) 884 seq_puts(seq, ",enospc_debug"); 885 if (btrfs_test_opt(root, AUTO_DEFRAG)) 886 seq_puts(seq, ",autodefrag"); 887 if (btrfs_test_opt(root, INODE_MAP_CACHE)) 888 seq_puts(seq, ",inode_cache"); 889 if (btrfs_test_opt(root, SKIP_BALANCE)) 890 seq_puts(seq, ",skip_balance"); 891 if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR)) 892 seq_puts(seq, ",fatal_errors=panic"); 893 return 0; 894 } 895 896 static int btrfs_test_super(struct super_block *s, void *data) 897 { 898 struct btrfs_fs_info *p = data; 899 struct btrfs_fs_info *fs_info = btrfs_sb(s); 900 901 return fs_info->fs_devices == p->fs_devices; 902 } 903 904 static int btrfs_set_super(struct super_block *s, void *data) 905 { 906 int err = set_anon_super(s, data); 907 if (!err) 908 s->s_fs_info = data; 909 return err; 910 } 911 912 /* 913 * subvolumes are identified by ino 256 914 */ 915 static inline int is_subvolume_inode(struct inode *inode) 916 { 917 if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID) 918 return 1; 919 return 0; 920 } 921 922 /* 923 * This will strip out the subvol=%s argument for an argument string and add 924 * subvolid=0 to make sure we get the actual tree root for path walking to the 925 * subvol we want. 926 */ 927 static char *setup_root_args(char *args) 928 { 929 unsigned copied = 0; 930 unsigned len = strlen(args) + 2; 931 char *pos; 932 char *ret; 933 934 /* 935 * We need the same args as before, but minus 936 * 937 * subvol=a 938 * 939 * and add 940 * 941 * subvolid=0 942 * 943 * which is a difference of 2 characters, so we allocate strlen(args) + 944 * 2 characters. 945 */ 946 ret = kzalloc(len * sizeof(char), GFP_NOFS); 947 if (!ret) 948 return NULL; 949 pos = strstr(args, "subvol="); 950 951 /* This shouldn't happen, but just in case.. */ 952 if (!pos) { 953 kfree(ret); 954 return NULL; 955 } 956 957 /* 958 * The subvol=<> arg is not at the front of the string, copy everybody 959 * up to that into ret. 960 */ 961 if (pos != args) { 962 *pos = '\0'; 963 strcpy(ret, args); 964 copied += strlen(args); 965 pos++; 966 } 967 968 strncpy(ret + copied, "subvolid=0", len - copied); 969 970 /* Length of subvolid=0 */ 971 copied += 10; 972 973 /* 974 * If there is no , after the subvol= option then we know there's no 975 * other options and we can just return. 976 */ 977 pos = strchr(pos, ','); 978 if (!pos) 979 return ret; 980 981 /* Copy the rest of the arguments into our buffer */ 982 strncpy(ret + copied, pos, len - copied); 983 copied += strlen(pos); 984 985 return ret; 986 } 987 988 static struct dentry *mount_subvol(const char *subvol_name, int flags, 989 const char *device_name, char *data) 990 { 991 struct dentry *root; 992 struct vfsmount *mnt; 993 char *newargs; 994 995 newargs = setup_root_args(data); 996 if (!newargs) 997 return ERR_PTR(-ENOMEM); 998 mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name, 999 newargs); 1000 kfree(newargs); 1001 if (IS_ERR(mnt)) 1002 return ERR_CAST(mnt); 1003 1004 root = mount_subtree(mnt, subvol_name); 1005 1006 if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) { 1007 struct super_block *s = root->d_sb; 1008 dput(root); 1009 root = ERR_PTR(-EINVAL); 1010 deactivate_locked_super(s); 1011 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n", 1012 subvol_name); 1013 } 1014 1015 return root; 1016 } 1017 1018 /* 1019 * Find a superblock for the given device / mount point. 1020 * 1021 * Note: This is based on get_sb_bdev from fs/super.c with a few additions 1022 * for multiple device setup. Make sure to keep it in sync. 1023 */ 1024 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags, 1025 const char *device_name, void *data) 1026 { 1027 struct block_device *bdev = NULL; 1028 struct super_block *s; 1029 struct dentry *root; 1030 struct btrfs_fs_devices *fs_devices = NULL; 1031 struct btrfs_fs_info *fs_info = NULL; 1032 fmode_t mode = FMODE_READ; 1033 char *subvol_name = NULL; 1034 u64 subvol_objectid = 0; 1035 u64 subvol_rootid = 0; 1036 int error = 0; 1037 1038 if (!(flags & MS_RDONLY)) 1039 mode |= FMODE_WRITE; 1040 1041 error = btrfs_parse_early_options(data, mode, fs_type, 1042 &subvol_name, &subvol_objectid, 1043 &subvol_rootid, &fs_devices); 1044 if (error) { 1045 kfree(subvol_name); 1046 return ERR_PTR(error); 1047 } 1048 1049 if (subvol_name) { 1050 root = mount_subvol(subvol_name, flags, device_name, data); 1051 kfree(subvol_name); 1052 return root; 1053 } 1054 1055 error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices); 1056 if (error) 1057 return ERR_PTR(error); 1058 1059 /* 1060 * Setup a dummy root and fs_info for test/set super. This is because 1061 * we don't actually fill this stuff out until open_ctree, but we need 1062 * it for searching for existing supers, so this lets us do that and 1063 * then open_ctree will properly initialize everything later. 1064 */ 1065 fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS); 1066 if (!fs_info) 1067 return ERR_PTR(-ENOMEM); 1068 1069 fs_info->fs_devices = fs_devices; 1070 1071 fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1072 fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS); 1073 if (!fs_info->super_copy || !fs_info->super_for_commit) { 1074 error = -ENOMEM; 1075 goto error_fs_info; 1076 } 1077 1078 error = btrfs_open_devices(fs_devices, mode, fs_type); 1079 if (error) 1080 goto error_fs_info; 1081 1082 if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) { 1083 error = -EACCES; 1084 goto error_close_devices; 1085 } 1086 1087 bdev = fs_devices->latest_bdev; 1088 s = sget(fs_type, btrfs_test_super, btrfs_set_super, fs_info); 1089 if (IS_ERR(s)) { 1090 error = PTR_ERR(s); 1091 goto error_close_devices; 1092 } 1093 1094 if (s->s_root) { 1095 btrfs_close_devices(fs_devices); 1096 free_fs_info(fs_info); 1097 if ((flags ^ s->s_flags) & MS_RDONLY) 1098 error = -EBUSY; 1099 } else { 1100 char b[BDEVNAME_SIZE]; 1101 1102 s->s_flags = flags | MS_NOSEC; 1103 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id)); 1104 btrfs_sb(s)->bdev_holder = fs_type; 1105 error = btrfs_fill_super(s, fs_devices, data, 1106 flags & MS_SILENT ? 1 : 0); 1107 } 1108 1109 root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error); 1110 if (IS_ERR(root)) 1111 deactivate_locked_super(s); 1112 1113 return root; 1114 1115 error_close_devices: 1116 btrfs_close_devices(fs_devices); 1117 error_fs_info: 1118 free_fs_info(fs_info); 1119 return ERR_PTR(error); 1120 } 1121 1122 static int btrfs_remount(struct super_block *sb, int *flags, char *data) 1123 { 1124 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1125 struct btrfs_root *root = fs_info->tree_root; 1126 unsigned old_flags = sb->s_flags; 1127 unsigned long old_opts = fs_info->mount_opt; 1128 unsigned long old_compress_type = fs_info->compress_type; 1129 u64 old_max_inline = fs_info->max_inline; 1130 u64 old_alloc_start = fs_info->alloc_start; 1131 int old_thread_pool_size = fs_info->thread_pool_size; 1132 unsigned int old_metadata_ratio = fs_info->metadata_ratio; 1133 int ret; 1134 1135 ret = btrfs_parse_options(root, data); 1136 if (ret) { 1137 ret = -EINVAL; 1138 goto restore; 1139 } 1140 1141 if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) 1142 return 0; 1143 1144 if (*flags & MS_RDONLY) { 1145 sb->s_flags |= MS_RDONLY; 1146 1147 ret = btrfs_commit_super(root); 1148 if (ret) 1149 goto restore; 1150 } else { 1151 if (fs_info->fs_devices->rw_devices == 0) 1152 ret = -EACCES; 1153 goto restore; 1154 1155 if (btrfs_super_log_root(fs_info->super_copy) != 0) 1156 ret = -EINVAL; 1157 goto restore; 1158 1159 ret = btrfs_cleanup_fs_roots(fs_info); 1160 if (ret) 1161 goto restore; 1162 1163 /* recover relocation */ 1164 ret = btrfs_recover_relocation(root); 1165 if (ret) 1166 goto restore; 1167 1168 sb->s_flags &= ~MS_RDONLY; 1169 } 1170 1171 return 0; 1172 1173 restore: 1174 /* We've hit an error - don't reset MS_RDONLY */ 1175 if (sb->s_flags & MS_RDONLY) 1176 old_flags |= MS_RDONLY; 1177 sb->s_flags = old_flags; 1178 fs_info->mount_opt = old_opts; 1179 fs_info->compress_type = old_compress_type; 1180 fs_info->max_inline = old_max_inline; 1181 fs_info->alloc_start = old_alloc_start; 1182 fs_info->thread_pool_size = old_thread_pool_size; 1183 fs_info->metadata_ratio = old_metadata_ratio; 1184 return ret; 1185 } 1186 1187 /* Used to sort the devices by max_avail(descending sort) */ 1188 static int btrfs_cmp_device_free_bytes(const void *dev_info1, 1189 const void *dev_info2) 1190 { 1191 if (((struct btrfs_device_info *)dev_info1)->max_avail > 1192 ((struct btrfs_device_info *)dev_info2)->max_avail) 1193 return -1; 1194 else if (((struct btrfs_device_info *)dev_info1)->max_avail < 1195 ((struct btrfs_device_info *)dev_info2)->max_avail) 1196 return 1; 1197 else 1198 return 0; 1199 } 1200 1201 /* 1202 * sort the devices by max_avail, in which max free extent size of each device 1203 * is stored.(Descending Sort) 1204 */ 1205 static inline void btrfs_descending_sort_devices( 1206 struct btrfs_device_info *devices, 1207 size_t nr_devices) 1208 { 1209 sort(devices, nr_devices, sizeof(struct btrfs_device_info), 1210 btrfs_cmp_device_free_bytes, NULL); 1211 } 1212 1213 /* 1214 * The helper to calc the free space on the devices that can be used to store 1215 * file data. 1216 */ 1217 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes) 1218 { 1219 struct btrfs_fs_info *fs_info = root->fs_info; 1220 struct btrfs_device_info *devices_info; 1221 struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; 1222 struct btrfs_device *device; 1223 u64 skip_space; 1224 u64 type; 1225 u64 avail_space; 1226 u64 used_space; 1227 u64 min_stripe_size; 1228 int min_stripes = 1, num_stripes = 1; 1229 int i = 0, nr_devices; 1230 int ret; 1231 1232 nr_devices = fs_info->fs_devices->open_devices; 1233 BUG_ON(!nr_devices); 1234 1235 devices_info = kmalloc(sizeof(*devices_info) * nr_devices, 1236 GFP_NOFS); 1237 if (!devices_info) 1238 return -ENOMEM; 1239 1240 /* calc min stripe number for data space alloction */ 1241 type = btrfs_get_alloc_profile(root, 1); 1242 if (type & BTRFS_BLOCK_GROUP_RAID0) { 1243 min_stripes = 2; 1244 num_stripes = nr_devices; 1245 } else if (type & BTRFS_BLOCK_GROUP_RAID1) { 1246 min_stripes = 2; 1247 num_stripes = 2; 1248 } else if (type & BTRFS_BLOCK_GROUP_RAID10) { 1249 min_stripes = 4; 1250 num_stripes = 4; 1251 } 1252 1253 if (type & BTRFS_BLOCK_GROUP_DUP) 1254 min_stripe_size = 2 * BTRFS_STRIPE_LEN; 1255 else 1256 min_stripe_size = BTRFS_STRIPE_LEN; 1257 1258 list_for_each_entry(device, &fs_devices->devices, dev_list) { 1259 if (!device->in_fs_metadata || !device->bdev) 1260 continue; 1261 1262 avail_space = device->total_bytes - device->bytes_used; 1263 1264 /* align with stripe_len */ 1265 do_div(avail_space, BTRFS_STRIPE_LEN); 1266 avail_space *= BTRFS_STRIPE_LEN; 1267 1268 /* 1269 * In order to avoid overwritting the superblock on the drive, 1270 * btrfs starts at an offset of at least 1MB when doing chunk 1271 * allocation. 1272 */ 1273 skip_space = 1024 * 1024; 1274 1275 /* user can set the offset in fs_info->alloc_start. */ 1276 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <= 1277 device->total_bytes) 1278 skip_space = max(fs_info->alloc_start, skip_space); 1279 1280 /* 1281 * btrfs can not use the free space in [0, skip_space - 1], 1282 * we must subtract it from the total. In order to implement 1283 * it, we account the used space in this range first. 1284 */ 1285 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1, 1286 &used_space); 1287 if (ret) { 1288 kfree(devices_info); 1289 return ret; 1290 } 1291 1292 /* calc the free space in [0, skip_space - 1] */ 1293 skip_space -= used_space; 1294 1295 /* 1296 * we can use the free space in [0, skip_space - 1], subtract 1297 * it from the total. 1298 */ 1299 if (avail_space && avail_space >= skip_space) 1300 avail_space -= skip_space; 1301 else 1302 avail_space = 0; 1303 1304 if (avail_space < min_stripe_size) 1305 continue; 1306 1307 devices_info[i].dev = device; 1308 devices_info[i].max_avail = avail_space; 1309 1310 i++; 1311 } 1312 1313 nr_devices = i; 1314 1315 btrfs_descending_sort_devices(devices_info, nr_devices); 1316 1317 i = nr_devices - 1; 1318 avail_space = 0; 1319 while (nr_devices >= min_stripes) { 1320 if (num_stripes > nr_devices) 1321 num_stripes = nr_devices; 1322 1323 if (devices_info[i].max_avail >= min_stripe_size) { 1324 int j; 1325 u64 alloc_size; 1326 1327 avail_space += devices_info[i].max_avail * num_stripes; 1328 alloc_size = devices_info[i].max_avail; 1329 for (j = i + 1 - num_stripes; j <= i; j++) 1330 devices_info[j].max_avail -= alloc_size; 1331 } 1332 i--; 1333 nr_devices--; 1334 } 1335 1336 kfree(devices_info); 1337 *free_bytes = avail_space; 1338 return 0; 1339 } 1340 1341 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf) 1342 { 1343 struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb); 1344 struct btrfs_super_block *disk_super = fs_info->super_copy; 1345 struct list_head *head = &fs_info->space_info; 1346 struct btrfs_space_info *found; 1347 u64 total_used = 0; 1348 u64 total_free_data = 0; 1349 int bits = dentry->d_sb->s_blocksize_bits; 1350 __be32 *fsid = (__be32 *)fs_info->fsid; 1351 int ret; 1352 1353 /* holding chunk_muext to avoid allocating new chunks */ 1354 mutex_lock(&fs_info->chunk_mutex); 1355 rcu_read_lock(); 1356 list_for_each_entry_rcu(found, head, list) { 1357 if (found->flags & BTRFS_BLOCK_GROUP_DATA) { 1358 total_free_data += found->disk_total - found->disk_used; 1359 total_free_data -= 1360 btrfs_account_ro_block_groups_free_space(found); 1361 } 1362 1363 total_used += found->disk_used; 1364 } 1365 rcu_read_unlock(); 1366 1367 buf->f_namelen = BTRFS_NAME_LEN; 1368 buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits; 1369 buf->f_bfree = buf->f_blocks - (total_used >> bits); 1370 buf->f_bsize = dentry->d_sb->s_blocksize; 1371 buf->f_type = BTRFS_SUPER_MAGIC; 1372 buf->f_bavail = total_free_data; 1373 ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data); 1374 if (ret) { 1375 mutex_unlock(&fs_info->chunk_mutex); 1376 return ret; 1377 } 1378 buf->f_bavail += total_free_data; 1379 buf->f_bavail = buf->f_bavail >> bits; 1380 mutex_unlock(&fs_info->chunk_mutex); 1381 1382 /* We treat it as constant endianness (it doesn't matter _which_) 1383 because we want the fsid to come out the same whether mounted 1384 on a big-endian or little-endian host */ 1385 buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]); 1386 buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]); 1387 /* Mask in the root object ID too, to disambiguate subvols */ 1388 buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32; 1389 buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid; 1390 1391 return 0; 1392 } 1393 1394 static void btrfs_kill_super(struct super_block *sb) 1395 { 1396 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1397 kill_anon_super(sb); 1398 free_fs_info(fs_info); 1399 } 1400 1401 static struct file_system_type btrfs_fs_type = { 1402 .owner = THIS_MODULE, 1403 .name = "btrfs", 1404 .mount = btrfs_mount, 1405 .kill_sb = btrfs_kill_super, 1406 .fs_flags = FS_REQUIRES_DEV, 1407 }; 1408 1409 /* 1410 * used by btrfsctl to scan devices when no FS is mounted 1411 */ 1412 static long btrfs_control_ioctl(struct file *file, unsigned int cmd, 1413 unsigned long arg) 1414 { 1415 struct btrfs_ioctl_vol_args *vol; 1416 struct btrfs_fs_devices *fs_devices; 1417 int ret = -ENOTTY; 1418 1419 if (!capable(CAP_SYS_ADMIN)) 1420 return -EPERM; 1421 1422 vol = memdup_user((void __user *)arg, sizeof(*vol)); 1423 if (IS_ERR(vol)) 1424 return PTR_ERR(vol); 1425 1426 switch (cmd) { 1427 case BTRFS_IOC_SCAN_DEV: 1428 ret = btrfs_scan_one_device(vol->name, FMODE_READ, 1429 &btrfs_fs_type, &fs_devices); 1430 break; 1431 } 1432 1433 kfree(vol); 1434 return ret; 1435 } 1436 1437 static int btrfs_freeze(struct super_block *sb) 1438 { 1439 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1440 mutex_lock(&fs_info->transaction_kthread_mutex); 1441 mutex_lock(&fs_info->cleaner_mutex); 1442 return 0; 1443 } 1444 1445 static int btrfs_unfreeze(struct super_block *sb) 1446 { 1447 struct btrfs_fs_info *fs_info = btrfs_sb(sb); 1448 mutex_unlock(&fs_info->cleaner_mutex); 1449 mutex_unlock(&fs_info->transaction_kthread_mutex); 1450 return 0; 1451 } 1452 1453 static void btrfs_fs_dirty_inode(struct inode *inode, int flags) 1454 { 1455 int ret; 1456 1457 ret = btrfs_dirty_inode(inode); 1458 if (ret) 1459 printk_ratelimited(KERN_ERR "btrfs: fail to dirty inode %Lu " 1460 "error %d\n", btrfs_ino(inode), ret); 1461 } 1462 1463 static const struct super_operations btrfs_super_ops = { 1464 .drop_inode = btrfs_drop_inode, 1465 .evict_inode = btrfs_evict_inode, 1466 .put_super = btrfs_put_super, 1467 .sync_fs = btrfs_sync_fs, 1468 .show_options = btrfs_show_options, 1469 .write_inode = btrfs_write_inode, 1470 .dirty_inode = btrfs_fs_dirty_inode, 1471 .alloc_inode = btrfs_alloc_inode, 1472 .destroy_inode = btrfs_destroy_inode, 1473 .statfs = btrfs_statfs, 1474 .remount_fs = btrfs_remount, 1475 .freeze_fs = btrfs_freeze, 1476 .unfreeze_fs = btrfs_unfreeze, 1477 }; 1478 1479 static const struct file_operations btrfs_ctl_fops = { 1480 .unlocked_ioctl = btrfs_control_ioctl, 1481 .compat_ioctl = btrfs_control_ioctl, 1482 .owner = THIS_MODULE, 1483 .llseek = noop_llseek, 1484 }; 1485 1486 static struct miscdevice btrfs_misc = { 1487 .minor = BTRFS_MINOR, 1488 .name = "btrfs-control", 1489 .fops = &btrfs_ctl_fops 1490 }; 1491 1492 MODULE_ALIAS_MISCDEV(BTRFS_MINOR); 1493 MODULE_ALIAS("devname:btrfs-control"); 1494 1495 static int btrfs_interface_init(void) 1496 { 1497 return misc_register(&btrfs_misc); 1498 } 1499 1500 static void btrfs_interface_exit(void) 1501 { 1502 if (misc_deregister(&btrfs_misc) < 0) 1503 printk(KERN_INFO "misc_deregister failed for control device"); 1504 } 1505 1506 static int __init init_btrfs_fs(void) 1507 { 1508 int err; 1509 1510 err = btrfs_init_sysfs(); 1511 if (err) 1512 return err; 1513 1514 btrfs_init_compress(); 1515 1516 err = btrfs_init_cachep(); 1517 if (err) 1518 goto free_compress; 1519 1520 err = extent_io_init(); 1521 if (err) 1522 goto free_cachep; 1523 1524 err = extent_map_init(); 1525 if (err) 1526 goto free_extent_io; 1527 1528 err = btrfs_delayed_inode_init(); 1529 if (err) 1530 goto free_extent_map; 1531 1532 err = btrfs_interface_init(); 1533 if (err) 1534 goto free_delayed_inode; 1535 1536 err = register_filesystem(&btrfs_fs_type); 1537 if (err) 1538 goto unregister_ioctl; 1539 1540 btrfs_init_lockdep(); 1541 1542 printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION); 1543 return 0; 1544 1545 unregister_ioctl: 1546 btrfs_interface_exit(); 1547 free_delayed_inode: 1548 btrfs_delayed_inode_exit(); 1549 free_extent_map: 1550 extent_map_exit(); 1551 free_extent_io: 1552 extent_io_exit(); 1553 free_cachep: 1554 btrfs_destroy_cachep(); 1555 free_compress: 1556 btrfs_exit_compress(); 1557 btrfs_exit_sysfs(); 1558 return err; 1559 } 1560 1561 static void __exit exit_btrfs_fs(void) 1562 { 1563 btrfs_destroy_cachep(); 1564 btrfs_delayed_inode_exit(); 1565 extent_map_exit(); 1566 extent_io_exit(); 1567 btrfs_interface_exit(); 1568 unregister_filesystem(&btrfs_fs_type); 1569 btrfs_exit_sysfs(); 1570 btrfs_cleanup_fs_uuids(); 1571 btrfs_exit_compress(); 1572 } 1573 1574 module_init(init_btrfs_fs) 1575 module_exit(exit_btrfs_fs) 1576 1577 MODULE_LICENSE("GPL"); 1578