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