fs/btrfs/super.c

   1 /*
   2  * Copyright (C) 2007 Oracle.  All rights reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public
   6  * License v2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public
  14  * License along with this program; if not, write to the
  15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  16  * Boston, MA 021110-1307, USA.
  17  */
  18
  19 #include <linux/blkdev.h>
  20 #include <linux/module.h>
  21 #include <linux/buffer_head.h>
  22 #include <linux/fs.h>
  23 #include <linux/pagemap.h>
  24 #include <linux/highmem.h>
  25 #include <linux/time.h>
  26 #include <linux/init.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/string.h>
  29 #include <linux/backing-dev.h>
  30 #include <linux/mount.h>
  31 #include <linux/mpage.h>
  32 #include <linux/swap.h>
  33 #include <linux/writeback.h>
  34 #include <linux/statfs.h>
  35 #include <linux/compat.h>
  36 #include <linux/parser.h>
  37 #include <linux/ctype.h>
  38 #include <linux/namei.h>
  39 #include <linux/miscdevice.h>
  40 #include <linux/magic.h>
  41 #include <linux/slab.h>
  42 #include <linux/cleancache.h>
  43 #include <linux/ratelimit.h>
  44 #include <linux/btrfs.h>
  45 #include "delayed-inode.h"
  46 #include "ctree.h"
  47 #include "disk-io.h"
  48 #include "transaction.h"
  49 #include "btrfs_inode.h"
  50 #include "print-tree.h"
  51 #include "xattr.h"
  52 #include "volumes.h"
  53 #include "export.h"
  54 #include "compression.h"
  55 #include "rcu-string.h"
  56 #include "dev-replace.h"
  57 #include "free-space-cache.h"
  58 #include "backref.h"
  59 #include "tests/btrfs-tests.h"
  60
  61 #define CREATE_TRACE_POINTS
  62 #include <trace/events/btrfs.h>
  63
  64 static const struct super_operations btrfs_super_ops;
  65 static struct file_system_type btrfs_fs_type;
  66
  67 static const char *btrfs_decode_error(int errno)
  68 {
  69         char *errstr = "unknown";
  70
  71         switch (errno) {
  72         case -EIO:
  73                 errstr = "IO failure";
  74                 break;
  75         case -ENOMEM:
  76                 errstr = "Out of memory";
  77                 break;
  78         case -EROFS:
  79                 errstr = "Readonly filesystem";
  80                 break;
  81         case -EEXIST:
  82                 errstr = "Object already exists";
  83                 break;
  84         case -ENOSPC:
  85                 errstr = "No space left";
  86                 break;
  87         case -ENOENT:
  88                 errstr = "No such entry";
  89                 break;
  90         }
  91
  92         return errstr;
  93 }
  94
  95 static void save_error_info(struct btrfs_fs_info *fs_info)
  96 {
  97         /*
  98          * today we only save the error info into ram.  Long term we'll
  99          * also send it down to the disk
 100          */
 101         set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
 102 }
 103
 104 /* btrfs handle error by forcing the filesystem readonly */
 105 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
 106 {
 107         struct super_block *sb = fs_info->sb;
 108
 109         if (sb->s_flags & MS_RDONLY)
 110                 return;
 111
 112         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
 113                 sb->s_flags |= MS_RDONLY;
 114                 btrfs_info(fs_info, "forced readonly");
 115                 /*
 116                  * Note that a running device replace operation is not
 117                  * canceled here although there is no way to update
 118                  * the progress. It would add the risk of a deadlock,
 119                  * therefore the canceling is ommited. The only penalty
 120                  * is that some I/O remains active until the procedure
 121                  * completes. The next time when the filesystem is
 122                  * mounted writeable again, the device replace
 123                  * operation continues.
 124                  */
 125         }
 126 }
 127
 128 #ifdef CONFIG_PRINTK
 129 /*
 130  * __btrfs_std_error decodes expected errors from the caller and
 131  * invokes the approciate error response.
 132  */
 133 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 134                        unsigned int line, int errno, const char *fmt, ...)
 135 {
 136         struct super_block *sb = fs_info->sb;
 137         const char *errstr;
 138
 139         /*
 140          * Special case: if the error is EROFS, and we're already
 141          * under MS_RDONLY, then it is safe here.
 142          */
 143         if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
 144                 return;
 145
 146         errstr = btrfs_decode_error(errno);
 147         if (fmt) {
 148                 struct va_format vaf;
 149                 va_list args;
 150
 151                 va_start(args, fmt);
 152                 vaf.fmt = fmt;
 153                 vaf.va = &args;
 154
 155                 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s (%pV)\n",
 156                         sb->s_id, function, line, errno, errstr, &vaf);
 157                 va_end(args);
 158         } else {
 159                 printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: errno=%d %s\n",
 160                         sb->s_id, function, line, errno, errstr);
 161         }
 162
 163         /* Don't go through full error handling during mount */
 164         save_error_info(fs_info);
 165         if (sb->s_flags & MS_BORN)
 166                 btrfs_handle_error(fs_info);
 167 }
 168
 169 static const char * const logtypes[] = {
 170         "emergency",
 171         "alert",
 172         "critical",
 173         "error",
 174         "warning",
 175         "notice",
 176         "info",
 177         "debug",
 178 };
 179
 180 void btrfs_printk(const 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         int kern_level;
 188
 189         va_start(args, fmt);
 190
 191         kern_level = printk_get_level(fmt);
 192         if (kern_level) {
 193                 size_t size = printk_skip_level(fmt) - fmt;
 194                 memcpy(lvl, fmt,  size);
 195                 lvl[size] = '\0';
 196                 fmt += size;
 197                 type = logtypes[kern_level - '0'];
 198         } else
 199                 *lvl = '\0';
 200
 201         vaf.fmt = fmt;
 202         vaf.va = &args;
 203
 204         printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
 205
 206         va_end(args);
 207 }
 208
 209 #else
 210
 211 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 212                        unsigned int line, int errno, const char *fmt, ...)
 213 {
 214         struct super_block *sb = fs_info->sb;
 215
 216         /*
 217          * Special case: if the error is EROFS, and we're already
 218          * under MS_RDONLY, then it is safe here.
 219          */
 220         if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
 221                 return;
 222
 223         /* Don't go through full error handling during mount */
 224         if (sb->s_flags & MS_BORN) {
 225                 save_error_info(fs_info);
 226                 btrfs_handle_error(fs_info);
 227         }
 228 }
 229 #endif
 230
 231 /*
 232  * We only mark the transaction aborted and then set the file system read-only.
 233  * This will prevent new transactions from starting or trying to join this
 234  * one.
 235  *
 236  * This means that error recovery at the call site is limited to freeing
 237  * any local memory allocations and passing the error code up without
 238  * further cleanup. The transaction should complete as it normally would
 239  * in the call path but will return -EIO.
 240  *
 241  * We'll complete the cleanup in btrfs_end_transaction and
 242  * btrfs_commit_transaction.
 243  */
 244 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
 245                                struct btrfs_root *root, const char *function,
 246                                unsigned int line, int errno)
 247 {
 248         /*
 249          * Report first abort since mount
 250          */
 251         if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
 252                                 &root->fs_info->fs_state)) {
 253                 WARN(1, KERN_DEBUG "btrfs: Transaction aborted (error %d)\n",
 254                                 errno);
 255         }
 256         trans->aborted = errno;
 257         /* Nothing used. The other threads that have joined this
 258          * transaction may be able to continue. */
 259         if (!trans->blocks_used) {
 260                 const char *errstr;
 261
 262                 errstr = btrfs_decode_error(errno);
 263                 btrfs_warn(root->fs_info,
 264                            "%s:%d: Aborting unused transaction(%s).",
 265                            function, line, errstr);
 266                 return;
 267         }
 268         ACCESS_ONCE(trans->transaction->aborted) = errno;
 269         /* Wake up anybody who may be waiting on this transaction */
 270         wake_up(&root->fs_info->transaction_wait);
 271         wake_up(&root->fs_info->transaction_blocked_wait);
 272         __btrfs_std_error(root->fs_info, function, line, errno, NULL);
 273 }
 274 /*
 275  * __btrfs_panic decodes unexpected, fatal errors from the caller,
 276  * issues an alert, and either panics or BUGs, depending on mount options.
 277  */
 278 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
 279                    unsigned int line, int errno, const char *fmt, ...)
 280 {
 281         char *s_id = "<unknown>";
 282         const char *errstr;
 283         struct va_format vaf = { .fmt = fmt };
 284         va_list args;
 285
 286         if (fs_info)
 287                 s_id = fs_info->sb->s_id;
 288
 289         va_start(args, fmt);
 290         vaf.va = &args;
 291
 292         errstr = btrfs_decode_error(errno);
 293         if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
 294                 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
 295                         s_id, function, line, &vaf, errno, errstr);
 296
 297         printk(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
 298                s_id, function, line, &vaf, errno, errstr);
 299         va_end(args);
 300         /* Caller calls BUG() */
 301 }
 302
 303 static void btrfs_put_super(struct super_block *sb)
 304 {
 305         (void)close_ctree(btrfs_sb(sb)->tree_root);
 306         /* FIXME: need to fix VFS to return error? */
 307         /* AV: return it _where_?  ->put_super() can be triggered by any number
 308          * of async events, up to and including delivery of SIGKILL to the
 309          * last process that kept it busy.  Or segfault in the aforementioned
 310          * process...  Whom would you report that to?
 311          */
 312 }
 313
 314 enum {
 315         Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
 316         Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
 317         Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
 318         Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
 319         Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
 320         Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
 321         Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
 322         Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
 323         Opt_check_integrity, Opt_check_integrity_including_extent_data,
 324         Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
 325         Opt_commit_interval,
 326         Opt_err,
 327 };
 328
 329 static match_table_t tokens = {
 330         {Opt_degraded, "degraded"},
 331         {Opt_subvol, "subvol=%s"},
 332         {Opt_subvolid, "subvolid=%s"},
 333         {Opt_device, "device=%s"},
 334         {Opt_nodatasum, "nodatasum"},
 335         {Opt_nodatacow, "nodatacow"},
 336         {Opt_nobarrier, "nobarrier"},
 337         {Opt_max_inline, "max_inline=%s"},
 338         {Opt_alloc_start, "alloc_start=%s"},
 339         {Opt_thread_pool, "thread_pool=%d"},
 340         {Opt_compress, "compress"},
 341         {Opt_compress_type, "compress=%s"},
 342         {Opt_compress_force, "compress-force"},
 343         {Opt_compress_force_type, "compress-force=%s"},
 344         {Opt_ssd, "ssd"},
 345         {Opt_ssd_spread, "ssd_spread"},
 346         {Opt_nossd, "nossd"},
 347         {Opt_noacl, "noacl"},
 348         {Opt_notreelog, "notreelog"},
 349         {Opt_flushoncommit, "flushoncommit"},
 350         {Opt_ratio, "metadata_ratio=%d"},
 351         {Opt_discard, "discard"},
 352         {Opt_space_cache, "space_cache"},
 353         {Opt_clear_cache, "clear_cache"},
 354         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
 355         {Opt_enospc_debug, "enospc_debug"},
 356         {Opt_subvolrootid, "subvolrootid=%d"},
 357         {Opt_defrag, "autodefrag"},
 358         {Opt_inode_cache, "inode_cache"},
 359         {Opt_no_space_cache, "nospace_cache"},
 360         {Opt_recovery, "recovery"},
 361         {Opt_skip_balance, "skip_balance"},
 362         {Opt_check_integrity, "check_int"},
 363         {Opt_check_integrity_including_extent_data, "check_int_data"},
 364         {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
 365         {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
 366         {Opt_fatal_errors, "fatal_errors=%s"},
 367         {Opt_commit_interval, "commit=%d"},
 368         {Opt_err, NULL},
 369 };
 370
 371 /*
 372  * Regular mount options parser.  Everything that is needed only when
 373  * reading in a new superblock is parsed here.
 374  * XXX JDM: This needs to be cleaned up for remount.
 375  */
 376 int btrfs_parse_options(struct btrfs_root *root, char *options)
 377 {
 378         struct btrfs_fs_info *info = root->fs_info;
 379         substring_t args[MAX_OPT_ARGS];
 380         char *p, *num, *orig = NULL;
 381         u64 cache_gen;
 382         int intarg;
 383         int ret = 0;
 384         char *compress_type;
 385         bool compress_force = false;
 386
 387         cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
 388         if (cache_gen)
 389                 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 390
 391         if (!options)
 392                 goto out;
 393
 394         /*
 395          * strsep changes the string, duplicate it because parse_options
 396          * gets called twice
 397          */
 398         options = kstrdup(options, GFP_NOFS);
 399         if (!options)
 400                 return -ENOMEM;
 401
 402         orig = options;
 403
 404         while ((p = strsep(&options, ",")) != NULL) {
 405                 int token;
 406                 if (!*p)
 407                         continue;
 408
 409                 token = match_token(p, tokens, args);
 410                 switch (token) {
 411                 case Opt_degraded:
 412                         printk(KERN_INFO "btrfs: allowing degraded mounts\n");
 413                         btrfs_set_opt(info->mount_opt, DEGRADED);
 414                         break;
 415                 case Opt_subvol:
 416                 case Opt_subvolid:
 417                 case Opt_subvolrootid:
 418                 case Opt_device:
 419                         /*
 420                          * These are parsed by btrfs_parse_early_options
 421                          * and can be happily ignored here.
 422                          */
 423                         break;
 424                 case Opt_nodatasum:
 425                         printk(KERN_INFO "btrfs: setting nodatasum\n");
 426                         btrfs_set_opt(info->mount_opt, NODATASUM);
 427                         break;
 428                 case Opt_nodatacow:
 429                         if (!btrfs_test_opt(root, COMPRESS) ||
 430                                 !btrfs_test_opt(root, FORCE_COMPRESS)) {
 431                                         printk(KERN_INFO "btrfs: setting nodatacow, compression disabled\n");
 432                         } else {
 433                                 printk(KERN_INFO "btrfs: setting nodatacow\n");
 434                         }
 435                         btrfs_clear_opt(info->mount_opt, COMPRESS);
 436                         btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 437                         btrfs_set_opt(info->mount_opt, NODATACOW);
 438                         btrfs_set_opt(info->mount_opt, NODATASUM);
 439                         break;
 440                 case Opt_compress_force:
 441                 case Opt_compress_force_type:
 442                         compress_force = true;
 443                         /* Fallthrough */
 444                 case Opt_compress:
 445                 case Opt_compress_type:
 446                         if (token == Opt_compress ||
 447                             token == Opt_compress_force ||
 448                             strcmp(args[0].from, "zlib") == 0) {
 449                                 compress_type = "zlib";
 450                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
 451                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 452                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 453                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 454                         } else if (strcmp(args[0].from, "lzo") == 0) {
 455                                 compress_type = "lzo";
 456                                 info->compress_type = BTRFS_COMPRESS_LZO;
 457                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 458                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 459                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 460                                 btrfs_set_fs_incompat(info, COMPRESS_LZO);
 461                         } else if (strncmp(args[0].from, "no", 2) == 0) {
 462                                 compress_type = "no";
 463                                 btrfs_clear_opt(info->mount_opt, COMPRESS);
 464                                 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 465                                 compress_force = false;
 466                         } else {
 467                                 ret = -EINVAL;
 468                                 goto out;
 469                         }
 470
 471                         if (compress_force) {
 472                                 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
 473                                 pr_info("btrfs: force %s compression\n",
 474                                         compress_type);
 475                         } else if (btrfs_test_opt(root, COMPRESS)) {
 476                                 pr_info("btrfs: use %s compression\n",
 477                                         compress_type);
 478                         }
 479                         break;
 480                 case Opt_ssd:
 481                         printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
 482                         btrfs_set_opt(info->mount_opt, SSD);
 483                         break;
 484                 case Opt_ssd_spread:
 485                         printk(KERN_INFO "btrfs: use spread ssd "
 486                                "allocation scheme\n");
 487                         btrfs_set_opt(info->mount_opt, SSD);
 488                         btrfs_set_opt(info->mount_opt, SSD_SPREAD);
 489                         break;
 490                 case Opt_nossd:
 491                         printk(KERN_INFO "btrfs: not using ssd allocation "
 492                                "scheme\n");
 493                         btrfs_set_opt(info->mount_opt, NOSSD);
 494                         btrfs_clear_opt(info->mount_opt, SSD);
 495                         btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
 496                         break;
 497                 case Opt_nobarrier:
 498                         printk(KERN_INFO "btrfs: turning off barriers\n");
 499                         btrfs_set_opt(info->mount_opt, NOBARRIER);
 500                         break;
 501                 case Opt_thread_pool:
 502                         ret = match_int(&args[0], &intarg);
 503                         if (ret) {
 504                                 goto out;
 505                         } else if (intarg > 0) {
 506                                 info->thread_pool_size = intarg;
 507                         } else {
 508                                 ret = -EINVAL;
 509                                 goto out;
 510                         }
 511                         break;
 512                 case Opt_max_inline:
 513                         num = match_strdup(&args[0]);
 514                         if (num) {
 515                                 info->max_inline = memparse(num, NULL);
 516                                 kfree(num);
 517
 518                                 if (info->max_inline) {
 519                                         info->max_inline = max_t(u64,
 520                                                 info->max_inline,
 521                                                 root->sectorsize);
 522                                 }
 523                                 printk(KERN_INFO "btrfs: max_inline at %llu\n",
 524                                         info->max_inline);
 525                         } else {
 526                                 ret = -ENOMEM;
 527                                 goto out;
 528                         }
 529                         break;
 530                 case Opt_alloc_start:
 531                         num = match_strdup(&args[0]);
 532                         if (num) {
 533                                 mutex_lock(&info->chunk_mutex);
 534                                 info->alloc_start = memparse(num, NULL);
 535                                 mutex_unlock(&info->chunk_mutex);
 536                                 kfree(num);
 537                                 printk(KERN_INFO
 538                                         "btrfs: allocations start at %llu\n",
 539                                         info->alloc_start);
 540                         } else {
 541                                 ret = -ENOMEM;
 542                                 goto out;
 543                         }
 544                         break;
 545                 case Opt_noacl:
 546                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
 547                         break;
 548                 case Opt_notreelog:
 549                         printk(KERN_INFO "btrfs: disabling tree log\n");
 550                         btrfs_set_opt(info->mount_opt, NOTREELOG);
 551                         break;
 552                 case Opt_flushoncommit:
 553                         printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
 554                         btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
 555                         break;
 556                 case Opt_ratio:
 557                         ret = match_int(&args[0], &intarg);
 558                         if (ret) {
 559                                 goto out;
 560                         } else if (intarg >= 0) {
 561                                 info->metadata_ratio = intarg;
 562                                 printk(KERN_INFO "btrfs: metadata ratio %d\n",
 563                                        info->metadata_ratio);
 564                         } else {
 565                                 ret = -EINVAL;
 566                                 goto out;
 567                         }
 568                         break;
 569                 case Opt_discard:
 570                         btrfs_set_opt(info->mount_opt, DISCARD);
 571                         break;
 572                 case Opt_space_cache:
 573                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 574                         break;
 575                 case Opt_rescan_uuid_tree:
 576                         btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
 577                         break;
 578                 case Opt_no_space_cache:
 579                         printk(KERN_INFO "btrfs: disabling disk space caching\n");
 580                         btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
 581                         break;
 582                 case Opt_inode_cache:
 583                         printk(KERN_INFO "btrfs: enabling inode map caching\n");
 584                         btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
 585                         break;
 586                 case Opt_clear_cache:
 587                         printk(KERN_INFO "btrfs: force clearing of disk cache\n");
 588                         btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
 589                         break;
 590                 case Opt_user_subvol_rm_allowed:
 591                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
 592                         break;
 593                 case Opt_enospc_debug:
 594                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
 595                         break;
 596                 case Opt_defrag:
 597                         printk(KERN_INFO "btrfs: enabling auto defrag\n");
 598                         btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
 599                         break;
 600                 case Opt_recovery:
 601                         printk(KERN_INFO "btrfs: enabling auto recovery\n");
 602                         btrfs_set_opt(info->mount_opt, RECOVERY);
 603                         break;
 604                 case Opt_skip_balance:
 605                         btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
 606                         break;
 607 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 608                 case Opt_check_integrity_including_extent_data:
 609                         printk(KERN_INFO "btrfs: enabling check integrity"
 610                                " including extent data\n");
 611                         btrfs_set_opt(info->mount_opt,
 612                                       CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
 613                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 614                         break;
 615                 case Opt_check_integrity:
 616                         printk(KERN_INFO "btrfs: enabling check integrity\n");
 617                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 618                         break;
 619                 case Opt_check_integrity_print_mask:
 620                         ret = match_int(&args[0], &intarg);
 621                         if (ret) {
 622                                 goto out;
 623                         } else if (intarg >= 0) {
 624                                 info->check_integrity_print_mask = intarg;
 625                                 printk(KERN_INFO "btrfs:"
 626                                        " check_integrity_print_mask 0x%x\n",
 627                                        info->check_integrity_print_mask);
 628                         } else {
 629                                 ret = -EINVAL;
 630                                 goto out;
 631                         }
 632                         break;
 633 #else
 634                 case Opt_check_integrity_including_extent_data:
 635                 case Opt_check_integrity:
 636                 case Opt_check_integrity_print_mask:
 637                         printk(KERN_ERR "btrfs: support for check_integrity*"
 638                                " not compiled in!\n");
 639                         ret = -EINVAL;
 640                         goto out;
 641 #endif
 642                 case Opt_fatal_errors:
 643                         if (strcmp(args[0].from, "panic") == 0)
 644                                 btrfs_set_opt(info->mount_opt,
 645                                               PANIC_ON_FATAL_ERROR);
 646                         else if (strcmp(args[0].from, "bug") == 0)
 647                                 btrfs_clear_opt(info->mount_opt,
 648                                               PANIC_ON_FATAL_ERROR);
 649                         else {
 650                                 ret = -EINVAL;
 651                                 goto out;
 652                         }
 653                         break;
 654                 case Opt_commit_interval:
 655                         intarg = 0;
 656                         ret = match_int(&args[0], &intarg);
 657                         if (ret < 0) {
 658                                 printk(KERN_ERR
 659                                         "btrfs: invalid commit interval\n");
 660                                 ret = -EINVAL;
 661                                 goto out;
 662                         }
 663                         if (intarg > 0) {
 664                                 if (intarg > 300) {
 665                                         printk(KERN_WARNING
 666                                             "btrfs: excessive commit interval %d\n",
 667                                                         intarg);
 668                                 }
 669                                 info->commit_interval = intarg;
 670                         } else {
 671                                 printk(KERN_INFO
 672                                     "btrfs: using default commit interval %ds\n",
 673                                     BTRFS_DEFAULT_COMMIT_INTERVAL);
 674                                 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
 675                         }
 676                         break;
 677                 case Opt_err:
 678                         printk(KERN_INFO "btrfs: unrecognized mount option "
 679                                "'%s'\n", p);
 680                         ret = -EINVAL;
 681                         goto out;
 682                 default:
 683                         break;
 684                 }
 685         }
 686 out:
 687         if (!ret && btrfs_test_opt(root, SPACE_CACHE))
 688                 printk(KERN_INFO "btrfs: disk space caching is enabled\n");
 689         kfree(orig);
 690         return ret;
 691 }
 692
 693 /*
 694  * Parse mount options that are required early in the mount process.
 695  *
 696  * All other options will be parsed on much later in the mount process and
 697  * only when we need to allocate a new super block.
 698  */
 699 static int btrfs_parse_early_options(const char *options, fmode_t flags,
 700                 void *holder, char **subvol_name, u64 *subvol_objectid,
 701                 struct btrfs_fs_devices **fs_devices)
 702 {
 703         substring_t args[MAX_OPT_ARGS];
 704         char *device_name, *opts, *orig, *p;
 705         char *num = NULL;
 706         int error = 0;
 707
 708         if (!options)
 709                 return 0;
 710
 711         /*
 712          * strsep changes the string, duplicate it because parse_options
 713          * gets called twice
 714          */
 715         opts = kstrdup(options, GFP_KERNEL);
 716         if (!opts)
 717                 return -ENOMEM;
 718         orig = opts;
 719
 720         while ((p = strsep(&opts, ",")) != NULL) {
 721                 int token;
 722                 if (!*p)
 723                         continue;
 724
 725                 token = match_token(p, tokens, args);
 726                 switch (token) {
 727                 case Opt_subvol:
 728                         kfree(*subvol_name);
 729                         *subvol_name = match_strdup(&args[0]);
 730                         if (!*subvol_name) {
 731                                 error = -ENOMEM;
 732                                 goto out;
 733                         }
 734                         break;
 735                 case Opt_subvolid:
 736                         num = match_strdup(&args[0]);
 737                         if (num) {
 738                                 *subvol_objectid = memparse(num, NULL);
 739                                 kfree(num);
 740                                 /* we want the original fs_tree */
 741                                 if (!*subvol_objectid)
 742                                         *subvol_objectid =
 743                                                 BTRFS_FS_TREE_OBJECTID;
 744                         } else {
 745                                 error = -EINVAL;
 746                                 goto out;
 747                         }
 748                         break;
 749                 case Opt_subvolrootid:
 750                         printk(KERN_WARNING
 751                                 "btrfs: 'subvolrootid' mount option is deprecated and has no effect\n");
 752                         break;
 753                 case Opt_device:
 754                         device_name = match_strdup(&args[0]);
 755                         if (!device_name) {
 756                                 error = -ENOMEM;
 757                                 goto out;
 758                         }
 759                         error = btrfs_scan_one_device(device_name,
 760                                         flags, holder, fs_devices);
 761                         kfree(device_name);
 762                         if (error)
 763                                 goto out;
 764                         break;
 765                 default:
 766                         break;
 767                 }
 768         }
 769
 770 out:
 771         kfree(orig);
 772         return error;
 773 }
 774
 775 static struct dentry *get_default_root(struct super_block *sb,
 776                                        u64 subvol_objectid)
 777 {
 778         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 779         struct btrfs_root *root = fs_info->tree_root;
 780         struct btrfs_root *new_root;
 781         struct btrfs_dir_item *di;
 782         struct btrfs_path *path;
 783         struct btrfs_key location;
 784         struct inode *inode;
 785         u64 dir_id;
 786         int new = 0;
 787
 788         /*
 789          * We have a specific subvol we want to mount, just setup location and
 790          * go look up the root.
 791          */
 792         if (subvol_objectid) {
 793                 location.objectid = subvol_objectid;
 794                 location.type = BTRFS_ROOT_ITEM_KEY;
 795                 location.offset = (u64)-1;
 796                 goto find_root;
 797         }
 798
 799         path = btrfs_alloc_path();
 800         if (!path)
 801                 return ERR_PTR(-ENOMEM);
 802         path->leave_spinning = 1;
 803
 804         /*
 805          * Find the "default" dir item which points to the root item that we
 806          * will mount by default if we haven't been given a specific subvolume
 807          * to mount.
 808          */
 809         dir_id = btrfs_super_root_dir(fs_info->super_copy);
 810         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
 811         if (IS_ERR(di)) {
 812                 btrfs_free_path(path);
 813                 return ERR_CAST(di);
 814         }
 815         if (!di) {
 816                 /*
 817                  * Ok the default dir item isn't there.  This is weird since
 818                  * it's always been there, but don't freak out, just try and
 819                  * mount to root most subvolume.
 820                  */
 821                 btrfs_free_path(path);
 822                 dir_id = BTRFS_FIRST_FREE_OBJECTID;
 823                 new_root = fs_info->fs_root;
 824                 goto setup_root;
 825         }
 826
 827         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 828         btrfs_free_path(path);
 829
 830 find_root:
 831         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
 832         if (IS_ERR(new_root))
 833                 return ERR_CAST(new_root);
 834
 835         dir_id = btrfs_root_dirid(&new_root->root_item);
 836 setup_root:
 837         location.objectid = dir_id;
 838         location.type = BTRFS_INODE_ITEM_KEY;
 839         location.offset = 0;
 840
 841         inode = btrfs_iget(sb, &location, new_root, &new);
 842         if (IS_ERR(inode))
 843                 return ERR_CAST(inode);
 844
 845         /*
 846          * If we're just mounting the root most subvol put the inode and return
 847          * a reference to the dentry.  We will have already gotten a reference
 848          * to the inode in btrfs_fill_super so we're good to go.
 849          */
 850         if (!new && sb->s_root->d_inode == inode) {
 851                 iput(inode);
 852                 return dget(sb->s_root);
 853         }
 854
 855         return d_obtain_alias(inode);
 856 }
 857
 858 static int btrfs_fill_super(struct super_block *sb,
 859                             struct btrfs_fs_devices *fs_devices,
 860                             void *data, int silent)
 861 {
 862         struct inode *inode;
 863         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 864         struct btrfs_key key;
 865         int err;
 866
 867         sb->s_maxbytes = MAX_LFS_FILESIZE;
 868         sb->s_magic = BTRFS_SUPER_MAGIC;
 869         sb->s_op = &btrfs_super_ops;
 870         sb->s_d_op = &btrfs_dentry_operations;
 871         sb->s_export_op = &btrfs_export_ops;
 872         sb->s_xattr = btrfs_xattr_handlers;
 873         sb->s_time_gran = 1;
 874 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 875         sb->s_flags |= MS_POSIXACL;
 876 #endif
 877         sb->s_flags |= MS_I_VERSION;
 878         err = open_ctree(sb, fs_devices, (char *)data);
 879         if (err) {
 880                 printk("btrfs: open_ctree failed\n");
 881                 return err;
 882         }
 883
 884         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 885         key.type = BTRFS_INODE_ITEM_KEY;
 886         key.offset = 0;
 887         inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
 888         if (IS_ERR(inode)) {
 889                 err = PTR_ERR(inode);
 890                 goto fail_close;
 891         }
 892
 893         sb->s_root = d_make_root(inode);
 894         if (!sb->s_root) {
 895                 err = -ENOMEM;
 896                 goto fail_close;
 897         }
 898
 899         save_mount_options(sb, data);
 900         cleancache_init_fs(sb);
 901         sb->s_flags |= MS_ACTIVE;
 902         return 0;
 903
 904 fail_close:
 905         close_ctree(fs_info->tree_root);
 906         return err;
 907 }
 908
 909 int btrfs_sync_fs(struct super_block *sb, int wait)
 910 {
 911         struct btrfs_trans_handle *trans;
 912         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 913         struct btrfs_root *root = fs_info->tree_root;
 914
 915         trace_btrfs_sync_fs(wait);
 916
 917         if (!wait) {
 918                 filemap_flush(fs_info->btree_inode->i_mapping);
 919                 return 0;
 920         }
 921
 922         btrfs_wait_ordered_roots(fs_info, -1);
 923
 924         trans = btrfs_attach_transaction_barrier(root);
 925         if (IS_ERR(trans)) {
 926                 /* no transaction, don't bother */
 927                 if (PTR_ERR(trans) == -ENOENT)
 928                         return 0;
 929                 return PTR_ERR(trans);
 930         }
 931         return btrfs_commit_transaction(trans, root);
 932 }
 933
 934 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 935 {
 936         struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
 937         struct btrfs_root *root = info->tree_root;
 938         char *compress_type;
 939
 940         if (btrfs_test_opt(root, DEGRADED))
 941                 seq_puts(seq, ",degraded");
 942         if (btrfs_test_opt(root, NODATASUM))
 943                 seq_puts(seq, ",nodatasum");
 944         if (btrfs_test_opt(root, NODATACOW))
 945                 seq_puts(seq, ",nodatacow");
 946         if (btrfs_test_opt(root, NOBARRIER))
 947                 seq_puts(seq, ",nobarrier");
 948         if (info->max_inline != 8192 * 1024)
 949                 seq_printf(seq, ",max_inline=%llu", info->max_inline);
 950         if (info->alloc_start != 0)
 951                 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
 952         if (info->thread_pool_size !=  min_t(unsigned long,
 953                                              num_online_cpus() + 2, 8))
 954                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
 955         if (btrfs_test_opt(root, COMPRESS)) {
 956                 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
 957                         compress_type = "zlib";
 958                 else
 959                         compress_type = "lzo";
 960                 if (btrfs_test_opt(root, FORCE_COMPRESS))
 961                         seq_printf(seq, ",compress-force=%s", compress_type);
 962                 else
 963                         seq_printf(seq, ",compress=%s", compress_type);
 964         }
 965         if (btrfs_test_opt(root, NOSSD))
 966                 seq_puts(seq, ",nossd");
 967         if (btrfs_test_opt(root, SSD_SPREAD))
 968                 seq_puts(seq, ",ssd_spread");
 969         else if (btrfs_test_opt(root, SSD))
 970                 seq_puts(seq, ",ssd");
 971         if (btrfs_test_opt(root, NOTREELOG))
 972                 seq_puts(seq, ",notreelog");
 973         if (btrfs_test_opt(root, FLUSHONCOMMIT))
 974                 seq_puts(seq, ",flushoncommit");
 975         if (btrfs_test_opt(root, DISCARD))
 976                 seq_puts(seq, ",discard");
 977         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
 978                 seq_puts(seq, ",noacl");
 979         if (btrfs_test_opt(root, SPACE_CACHE))
 980                 seq_puts(seq, ",space_cache");
 981         else
 982                 seq_puts(seq, ",nospace_cache");
 983         if (btrfs_test_opt(root, RESCAN_UUID_TREE))
 984                 seq_puts(seq, ",rescan_uuid_tree");
 985         if (btrfs_test_opt(root, CLEAR_CACHE))
 986                 seq_puts(seq, ",clear_cache");
 987         if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
 988                 seq_puts(seq, ",user_subvol_rm_allowed");
 989         if (btrfs_test_opt(root, ENOSPC_DEBUG))
 990                 seq_puts(seq, ",enospc_debug");
 991         if (btrfs_test_opt(root, AUTO_DEFRAG))
 992                 seq_puts(seq, ",autodefrag");
 993         if (btrfs_test_opt(root, INODE_MAP_CACHE))
 994                 seq_puts(seq, ",inode_cache");
 995         if (btrfs_test_opt(root, SKIP_BALANCE))
 996                 seq_puts(seq, ",skip_balance");
 997         if (btrfs_test_opt(root, RECOVERY))
 998                 seq_puts(seq, ",recovery");
 999 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1000         if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1001                 seq_puts(seq, ",check_int_data");
1002         else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1003                 seq_puts(seq, ",check_int");
1004         if (info->check_integrity_print_mask)
1005                 seq_printf(seq, ",check_int_print_mask=%d",
1006                                 info->check_integrity_print_mask);
1007 #endif
1008         if (info->metadata_ratio)
1009                 seq_printf(seq, ",metadata_ratio=%d",
1010                                 info->metadata_ratio);
1011         if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1012                 seq_puts(seq, ",fatal_errors=panic");
1013         if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1014                 seq_printf(seq, ",commit=%d", info->commit_interval);
1015         return 0;
1016 }
1017
1018 static int btrfs_test_super(struct super_block *s, void *data)
1019 {
1020         struct btrfs_fs_info *p = data;
1021         struct btrfs_fs_info *fs_info = btrfs_sb(s);
1022
1023         return fs_info->fs_devices == p->fs_devices;
1024 }
1025
1026 static int btrfs_set_super(struct super_block *s, void *data)
1027 {
1028         int err = set_anon_super(s, data);
1029         if (!err)
1030                 s->s_fs_info = data;
1031         return err;
1032 }
1033
1034 /*
1035  * subvolumes are identified by ino 256
1036  */
1037 static inline int is_subvolume_inode(struct inode *inode)
1038 {
1039         if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1040                 return 1;
1041         return 0;
1042 }
1043
1044 /*
1045  * This will strip out the subvol=%s argument for an argument string and add
1046  * subvolid=0 to make sure we get the actual tree root for path walking to the
1047  * subvol we want.
1048  */
1049 static char *setup_root_args(char *args)
1050 {
1051         unsigned len = strlen(args) + 2 + 1;
1052         char *src, *dst, *buf;
1053
1054         /*
1055          * We need the same args as before, but with this substitution:
1056          * s!subvol=[^,]+!subvolid=0!
1057          *
1058          * Since the replacement string is up to 2 bytes longer than the
1059          * original, allocate strlen(args) + 2 + 1 bytes.
1060          */
1061
1062         src = strstr(args, "subvol=");
1063         /* This shouldn't happen, but just in case.. */
1064         if (!src)
1065                 return NULL;
1066
1067         buf = dst = kmalloc(len, GFP_NOFS);
1068         if (!buf)
1069                 return NULL;
1070
1071         /*
1072          * If the subvol= arg is not at the start of the string,
1073          * copy whatever precedes it into buf.
1074          */
1075         if (src != args) {
1076                 *src++ = '\0';
1077                 strcpy(buf, args);
1078                 dst += strlen(args);
1079         }
1080
1081         strcpy(dst, "subvolid=0");
1082         dst += strlen("subvolid=0");
1083
1084         /*
1085          * If there is a "," after the original subvol=... string,
1086          * copy that suffix into our buffer.  Otherwise, we're done.
1087          */
1088         src = strchr(src, ',');
1089         if (src)
1090                 strcpy(dst, src);
1091
1092         return buf;
1093 }
1094
1095 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1096                                    const char *device_name, char *data)
1097 {
1098         struct dentry *root;
1099         struct vfsmount *mnt;
1100         char *newargs;
1101
1102         newargs = setup_root_args(data);
1103         if (!newargs)
1104                 return ERR_PTR(-ENOMEM);
1105         mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1106                              newargs);
1107         kfree(newargs);
1108         if (IS_ERR(mnt))
1109                 return ERR_CAST(mnt);
1110
1111         root = mount_subtree(mnt, subvol_name);
1112
1113         if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1114                 struct super_block *s = root->d_sb;
1115                 dput(root);
1116                 root = ERR_PTR(-EINVAL);
1117                 deactivate_locked_super(s);
1118                 printk(KERN_ERR "btrfs: '%s' is not a valid subvolume\n",
1119                                 subvol_name);
1120         }
1121
1122         return root;
1123 }
1124
1125 /*
1126  * Find a superblock for the given device / mount point.
1127  *
1128  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
1129  *        for multiple device setup.  Make sure to keep it in sync.
1130  */
1131 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1132                 const char *device_name, void *data)
1133 {
1134         struct block_device *bdev = NULL;
1135         struct super_block *s;
1136         struct dentry *root;
1137         struct btrfs_fs_devices *fs_devices = NULL;
1138         struct btrfs_fs_info *fs_info = NULL;
1139         fmode_t mode = FMODE_READ;
1140         char *subvol_name = NULL;
1141         u64 subvol_objectid = 0;
1142         int error = 0;
1143
1144         if (!(flags & MS_RDONLY))
1145                 mode |= FMODE_WRITE;
1146
1147         error = btrfs_parse_early_options(data, mode, fs_type,
1148                                           &subvol_name, &subvol_objectid,
1149                                           &fs_devices);
1150         if (error) {
1151                 kfree(subvol_name);
1152                 return ERR_PTR(error);
1153         }
1154
1155         if (subvol_name) {
1156                 root = mount_subvol(subvol_name, flags, device_name, data);
1157                 kfree(subvol_name);
1158                 return root;
1159         }
1160
1161         error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1162         if (error)
1163                 return ERR_PTR(error);
1164
1165         /*
1166          * Setup a dummy root and fs_info for test/set super.  This is because
1167          * we don't actually fill this stuff out until open_ctree, but we need
1168          * it for searching for existing supers, so this lets us do that and
1169          * then open_ctree will properly initialize everything later.
1170          */
1171         fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1172         if (!fs_info)
1173                 return ERR_PTR(-ENOMEM);
1174
1175         fs_info->fs_devices = fs_devices;
1176
1177         fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1178         fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1179         if (!fs_info->super_copy || !fs_info->super_for_commit) {
1180                 error = -ENOMEM;
1181                 goto error_fs_info;
1182         }
1183
1184         error = btrfs_open_devices(fs_devices, mode, fs_type);
1185         if (error)
1186                 goto error_fs_info;
1187
1188         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1189                 error = -EACCES;
1190                 goto error_close_devices;
1191         }
1192
1193         bdev = fs_devices->latest_bdev;
1194         s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1195                  fs_info);
1196         if (IS_ERR(s)) {
1197                 error = PTR_ERR(s);
1198                 goto error_close_devices;
1199         }
1200
1201         if (s->s_root) {
1202                 btrfs_close_devices(fs_devices);
1203                 free_fs_info(fs_info);
1204                 if ((flags ^ s->s_flags) & MS_RDONLY)
1205                         error = -EBUSY;
1206         } else {
1207                 char b[BDEVNAME_SIZE];
1208
1209                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1210                 btrfs_sb(s)->bdev_holder = fs_type;
1211                 error = btrfs_fill_super(s, fs_devices, data,
1212                                          flags & MS_SILENT ? 1 : 0);
1213         }
1214
1215         root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1216         if (IS_ERR(root))
1217                 deactivate_locked_super(s);
1218
1219         return root;
1220
1221 error_close_devices:
1222         btrfs_close_devices(fs_devices);
1223 error_fs_info:
1224         free_fs_info(fs_info);
1225         return ERR_PTR(error);
1226 }
1227
1228 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1229 {
1230         spin_lock_irq(&workers->lock);
1231         workers->max_workers = new_limit;
1232         spin_unlock_irq(&workers->lock);
1233 }
1234
1235 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1236                                      int new_pool_size, int old_pool_size)
1237 {
1238         if (new_pool_size == old_pool_size)
1239                 return;
1240
1241         fs_info->thread_pool_size = new_pool_size;
1242
1243         printk(KERN_INFO "btrfs: resize thread pool %d -> %d\n",
1244                old_pool_size, new_pool_size);
1245
1246         btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1247         btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1248         btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1249         btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1250         btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1251         btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1252         btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1253         btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1254         btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1255         btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1256         btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1257         btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1258         btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1259         btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1260                               new_pool_size);
1261 }
1262
1263 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1264 {
1265         set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1266 }
1267
1268 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1269                                        unsigned long old_opts, int flags)
1270 {
1271         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1272             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1273              (flags & MS_RDONLY))) {
1274                 /* wait for any defraggers to finish */
1275                 wait_event(fs_info->transaction_wait,
1276                            (atomic_read(&fs_info->defrag_running) == 0));
1277                 if (flags & MS_RDONLY)
1278                         sync_filesystem(fs_info->sb);
1279         }
1280 }
1281
1282 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1283                                          unsigned long old_opts)
1284 {
1285         /*
1286          * We need cleanup all defragable inodes if the autodefragment is
1287          * close or the fs is R/O.
1288          */
1289         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1290             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1291              (fs_info->sb->s_flags & MS_RDONLY))) {
1292                 btrfs_cleanup_defrag_inodes(fs_info);
1293         }
1294
1295         clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1296 }
1297
1298 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1299 {
1300         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1301         struct btrfs_root *root = fs_info->tree_root;
1302         unsigned old_flags = sb->s_flags;
1303         unsigned long old_opts = fs_info->mount_opt;
1304         unsigned long old_compress_type = fs_info->compress_type;
1305         u64 old_max_inline = fs_info->max_inline;
1306         u64 old_alloc_start = fs_info->alloc_start;
1307         int old_thread_pool_size = fs_info->thread_pool_size;
1308         unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1309         int ret;
1310
1311         btrfs_remount_prepare(fs_info);
1312
1313         ret = btrfs_parse_options(root, data);
1314         if (ret) {
1315                 ret = -EINVAL;
1316                 goto restore;
1317         }
1318
1319         btrfs_remount_begin(fs_info, old_opts, *flags);
1320         btrfs_resize_thread_pool(fs_info,
1321                 fs_info->thread_pool_size, old_thread_pool_size);
1322
1323         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1324                 goto out;
1325
1326         if (*flags & MS_RDONLY) {
1327                 /*
1328                  * this also happens on 'umount -rf' or on shutdown, when
1329                  * the filesystem is busy.
1330                  */
1331
1332                 /* wait for the uuid_scan task to finish */
1333                 down(&fs_info->uuid_tree_rescan_sem);
1334                 /* avoid complains from lockdep et al. */
1335                 up(&fs_info->uuid_tree_rescan_sem);
1336
1337                 sb->s_flags |= MS_RDONLY;
1338
1339                 btrfs_dev_replace_suspend_for_unmount(fs_info);
1340                 btrfs_scrub_cancel(fs_info);
1341                 btrfs_pause_balance(fs_info);
1342
1343                 ret = btrfs_commit_super(root);
1344                 if (ret)
1345                         goto restore;
1346         } else {
1347                 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1348                         btrfs_err(fs_info,
1349                                 "Remounting read-write after error is not allowed\n");
1350                         ret = -EINVAL;
1351                         goto restore;
1352                 }
1353                 if (fs_info->fs_devices->rw_devices == 0) {
1354                         ret = -EACCES;
1355                         goto restore;
1356                 }
1357
1358                 if (fs_info->fs_devices->missing_devices >
1359                      fs_info->num_tolerated_disk_barrier_failures &&
1360                     !(*flags & MS_RDONLY)) {
1361                         printk(KERN_WARNING
1362                                "Btrfs: too many missing devices, writeable remount is not allowed\n");
1363                         ret = -EACCES;
1364                         goto restore;
1365                 }
1366
1367                 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1368                         ret = -EINVAL;
1369                         goto restore;
1370                 }
1371
1372                 ret = btrfs_cleanup_fs_roots(fs_info);
1373                 if (ret)
1374                         goto restore;
1375
1376                 /* recover relocation */
1377                 ret = btrfs_recover_relocation(root);
1378                 if (ret)
1379                         goto restore;
1380
1381                 ret = btrfs_resume_balance_async(fs_info);
1382                 if (ret)
1383                         goto restore;
1384
1385                 ret = btrfs_resume_dev_replace_async(fs_info);
1386                 if (ret) {
1387                         pr_warn("btrfs: failed to resume dev_replace\n");
1388                         goto restore;
1389                 }
1390
1391                 if (!fs_info->uuid_root) {
1392                         pr_info("btrfs: creating UUID tree\n");
1393                         ret = btrfs_create_uuid_tree(fs_info);
1394                         if (ret) {
1395                                 pr_warn("btrfs: failed to create the uuid tree"
1396                                         "%d\n", ret);
1397                                 goto restore;
1398                         }
1399                 }
1400                 sb->s_flags &= ~MS_RDONLY;
1401         }
1402 out:
1403         btrfs_remount_cleanup(fs_info, old_opts);
1404         return 0;
1405
1406 restore:
1407         /* We've hit an error - don't reset MS_RDONLY */
1408         if (sb->s_flags & MS_RDONLY)
1409                 old_flags |= MS_RDONLY;
1410         sb->s_flags = old_flags;
1411         fs_info->mount_opt = old_opts;
1412         fs_info->compress_type = old_compress_type;
1413         fs_info->max_inline = old_max_inline;
1414         mutex_lock(&fs_info->chunk_mutex);
1415         fs_info->alloc_start = old_alloc_start;
1416         mutex_unlock(&fs_info->chunk_mutex);
1417         btrfs_resize_thread_pool(fs_info,
1418                 old_thread_pool_size, fs_info->thread_pool_size);
1419         fs_info->metadata_ratio = old_metadata_ratio;
1420         btrfs_remount_cleanup(fs_info, old_opts);
1421         return ret;
1422 }
1423
1424 /* Used to sort the devices by max_avail(descending sort) */
1425 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1426                                        const void *dev_info2)
1427 {
1428         if (((struct btrfs_device_info *)dev_info1)->max_avail >
1429             ((struct btrfs_device_info *)dev_info2)->max_avail)
1430                 return -1;
1431         else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1432                  ((struct btrfs_device_info *)dev_info2)->max_avail)
1433                 return 1;
1434         else
1435         return 0;
1436 }
1437
1438 /*
1439  * sort the devices by max_avail, in which max free extent size of each device
1440  * is stored.(Descending Sort)
1441  */
1442 static inline void btrfs_descending_sort_devices(
1443                                         struct btrfs_device_info *devices,
1444                                         size_t nr_devices)
1445 {
1446         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1447              btrfs_cmp_device_free_bytes, NULL);
1448 }
1449
1450 /*
1451  * The helper to calc the free space on the devices that can be used to store
1452  * file data.
1453  */
1454 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1455 {
1456         struct btrfs_fs_info *fs_info = root->fs_info;
1457         struct btrfs_device_info *devices_info;
1458         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1459         struct btrfs_device *device;
1460         u64 skip_space;
1461         u64 type;
1462         u64 avail_space;
1463         u64 used_space;
1464         u64 min_stripe_size;
1465         int min_stripes = 1, num_stripes = 1;
1466         int i = 0, nr_devices;
1467         int ret;
1468
1469         nr_devices = fs_info->fs_devices->open_devices;
1470         BUG_ON(!nr_devices);
1471
1472         devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1473                                GFP_NOFS);
1474         if (!devices_info)
1475                 return -ENOMEM;
1476
1477         /* calc min stripe number for data space alloction */
1478         type = btrfs_get_alloc_profile(root, 1);
1479         if (type & BTRFS_BLOCK_GROUP_RAID0) {
1480                 min_stripes = 2;
1481                 num_stripes = nr_devices;
1482         } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1483                 min_stripes = 2;
1484                 num_stripes = 2;
1485         } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1486                 min_stripes = 4;
1487                 num_stripes = 4;
1488         }
1489
1490         if (type & BTRFS_BLOCK_GROUP_DUP)
1491                 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1492         else
1493                 min_stripe_size = BTRFS_STRIPE_LEN;
1494
1495         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1496                 if (!device->in_fs_metadata || !device->bdev ||
1497                     device->is_tgtdev_for_dev_replace)
1498                         continue;
1499
1500                 avail_space = device->total_bytes - device->bytes_used;
1501
1502                 /* align with stripe_len */
1503                 do_div(avail_space, BTRFS_STRIPE_LEN);
1504                 avail_space *= BTRFS_STRIPE_LEN;
1505
1506                 /*
1507                  * In order to avoid overwritting the superblock on the drive,
1508                  * btrfs starts at an offset of at least 1MB when doing chunk
1509                  * allocation.
1510                  */
1511                 skip_space = 1024 * 1024;
1512
1513                 /* user can set the offset in fs_info->alloc_start. */
1514                 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1515                     device->total_bytes)
1516                         skip_space = max(fs_info->alloc_start, skip_space);
1517
1518                 /*
1519                  * btrfs can not use the free space in [0, skip_space - 1],
1520                  * we must subtract it from the total. In order to implement
1521                  * it, we account the used space in this range first.
1522                  */
1523                 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1524                                                      &used_space);
1525                 if (ret) {
1526                         kfree(devices_info);
1527                         return ret;
1528                 }
1529
1530                 /* calc the free space in [0, skip_space - 1] */
1531                 skip_space -= used_space;
1532
1533                 /*
1534                  * we can use the free space in [0, skip_space - 1], subtract
1535                  * it from the total.
1536                  */
1537                 if (avail_space && avail_space >= skip_space)
1538                         avail_space -= skip_space;
1539                 else
1540                         avail_space = 0;
1541
1542                 if (avail_space < min_stripe_size)
1543                         continue;
1544
1545                 devices_info[i].dev = device;
1546                 devices_info[i].max_avail = avail_space;
1547
1548                 i++;
1549         }
1550
1551         nr_devices = i;
1552
1553         btrfs_descending_sort_devices(devices_info, nr_devices);
1554
1555         i = nr_devices - 1;
1556         avail_space = 0;
1557         while (nr_devices >= min_stripes) {
1558                 if (num_stripes > nr_devices)
1559                         num_stripes = nr_devices;
1560
1561                 if (devices_info[i].max_avail >= min_stripe_size) {
1562                         int j;
1563                         u64 alloc_size;
1564
1565                         avail_space += devices_info[i].max_avail * num_stripes;
1566                         alloc_size = devices_info[i].max_avail;
1567                         for (j = i + 1 - num_stripes; j <= i; j++)
1568                                 devices_info[j].max_avail -= alloc_size;
1569                 }
1570                 i--;
1571                 nr_devices--;
1572         }
1573
1574         kfree(devices_info);
1575         *free_bytes = avail_space;
1576         return 0;
1577 }
1578
1579 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1580 {
1581         struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1582         struct btrfs_super_block *disk_super = fs_info->super_copy;
1583         struct list_head *head = &fs_info->space_info;
1584         struct btrfs_space_info *found;
1585         u64 total_used = 0;
1586         u64 total_free_data = 0;
1587         int bits = dentry->d_sb->s_blocksize_bits;
1588         __be32 *fsid = (__be32 *)fs_info->fsid;
1589         int ret;
1590
1591         /* holding chunk_muext to avoid allocating new chunks */
1592         mutex_lock(&fs_info->chunk_mutex);
1593         rcu_read_lock();
1594         list_for_each_entry_rcu(found, head, list) {
1595                 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1596                         total_free_data += found->disk_total - found->disk_used;
1597                         total_free_data -=
1598                                 btrfs_account_ro_block_groups_free_space(found);
1599                 }
1600
1601                 total_used += found->disk_used;
1602         }
1603         rcu_read_unlock();
1604
1605         buf->f_namelen = BTRFS_NAME_LEN;
1606         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1607         buf->f_bfree = buf->f_blocks - (total_used >> bits);
1608         buf->f_bsize = dentry->d_sb->s_blocksize;
1609         buf->f_type = BTRFS_SUPER_MAGIC;
1610         buf->f_bavail = total_free_data;
1611         ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1612         if (ret) {
1613                 mutex_unlock(&fs_info->chunk_mutex);
1614                 return ret;
1615         }
1616         buf->f_bavail += total_free_data;
1617         buf->f_bavail = buf->f_bavail >> bits;
1618         mutex_unlock(&fs_info->chunk_mutex);
1619
1620         /* We treat it as constant endianness (it doesn't matter _which_)
1621            because we want the fsid to come out the same whether mounted
1622            on a big-endian or little-endian host */
1623         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1624         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1625         /* Mask in the root object ID too, to disambiguate subvols */
1626         buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1627         buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1628
1629         return 0;
1630 }
1631
1632 static void btrfs_kill_super(struct super_block *sb)
1633 {
1634         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1635         kill_anon_super(sb);
1636         free_fs_info(fs_info);
1637 }
1638
1639 static struct file_system_type btrfs_fs_type = {
1640         .owner          = THIS_MODULE,
1641         .name           = "btrfs",
1642         .mount          = btrfs_mount,
1643         .kill_sb        = btrfs_kill_super,
1644         .fs_flags       = FS_REQUIRES_DEV,
1645 };
1646 MODULE_ALIAS_FS("btrfs");
1647
1648 /*
1649  * used by btrfsctl to scan devices when no FS is mounted
1650  */
1651 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1652                                 unsigned long arg)
1653 {
1654         struct btrfs_ioctl_vol_args *vol;
1655         struct btrfs_fs_devices *fs_devices;
1656         int ret = -ENOTTY;
1657
1658         if (!capable(CAP_SYS_ADMIN))
1659                 return -EPERM;
1660
1661         vol = memdup_user((void __user *)arg, sizeof(*vol));
1662         if (IS_ERR(vol))
1663                 return PTR_ERR(vol);
1664
1665         switch (cmd) {
1666         case BTRFS_IOC_SCAN_DEV:
1667                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1668                                             &btrfs_fs_type, &fs_devices);
1669                 break;
1670         case BTRFS_IOC_DEVICES_READY:
1671                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1672                                             &btrfs_fs_type, &fs_devices);
1673                 if (ret)
1674                         break;
1675                 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1676                 break;
1677         }
1678
1679         kfree(vol);
1680         return ret;
1681 }
1682
1683 static int btrfs_freeze(struct super_block *sb)
1684 {
1685         struct btrfs_trans_handle *trans;
1686         struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1687
1688         trans = btrfs_attach_transaction_barrier(root);
1689         if (IS_ERR(trans)) {
1690                 /* no transaction, don't bother */
1691                 if (PTR_ERR(trans) == -ENOENT)
1692                         return 0;
1693                 return PTR_ERR(trans);
1694         }
1695         return btrfs_commit_transaction(trans, root);
1696 }
1697
1698 static int btrfs_unfreeze(struct super_block *sb)
1699 {
1700         return 0;
1701 }
1702
1703 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1704 {
1705         struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1706         struct btrfs_fs_devices *cur_devices;
1707         struct btrfs_device *dev, *first_dev = NULL;
1708         struct list_head *head;
1709         struct rcu_string *name;
1710
1711         mutex_lock(&fs_info->fs_devices->device_list_mutex);
1712         cur_devices = fs_info->fs_devices;
1713         while (cur_devices) {
1714                 head = &cur_devices->devices;
1715                 list_for_each_entry(dev, head, dev_list) {
1716                         if (dev->missing)
1717                                 continue;
1718                         if (!first_dev || dev->devid < first_dev->devid)
1719                                 first_dev = dev;
1720                 }
1721                 cur_devices = cur_devices->seed;
1722         }
1723
1724         if (first_dev) {
1725                 rcu_read_lock();
1726                 name = rcu_dereference(first_dev->name);
1727                 seq_escape(m, name->str, " \t\n\\");
1728                 rcu_read_unlock();
1729         } else {
1730                 WARN_ON(1);
1731         }
1732         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1733         return 0;
1734 }
1735
1736 static const struct super_operations btrfs_super_ops = {
1737         .drop_inode     = btrfs_drop_inode,
1738         .evict_inode    = btrfs_evict_inode,
1739         .put_super      = btrfs_put_super,
1740         .sync_fs        = btrfs_sync_fs,
1741         .show_options   = btrfs_show_options,
1742         .show_devname   = btrfs_show_devname,
1743         .write_inode    = btrfs_write_inode,
1744         .alloc_inode    = btrfs_alloc_inode,
1745         .destroy_inode  = btrfs_destroy_inode,
1746         .statfs         = btrfs_statfs,
1747         .remount_fs     = btrfs_remount,
1748         .freeze_fs      = btrfs_freeze,
1749         .unfreeze_fs    = btrfs_unfreeze,
1750 };
1751
1752 static const struct file_operations btrfs_ctl_fops = {
1753         .unlocked_ioctl  = btrfs_control_ioctl,
1754         .compat_ioctl = btrfs_control_ioctl,
1755         .owner   = THIS_MODULE,
1756         .llseek = noop_llseek,
1757 };
1758
1759 static struct miscdevice btrfs_misc = {
1760         .minor          = BTRFS_MINOR,
1761         .name           = "btrfs-control",
1762         .fops           = &btrfs_ctl_fops
1763 };
1764
1765 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1766 MODULE_ALIAS("devname:btrfs-control");
1767
1768 static int btrfs_interface_init(void)
1769 {
1770         return misc_register(&btrfs_misc);
1771 }
1772
1773 static void btrfs_interface_exit(void)
1774 {
1775         if (misc_deregister(&btrfs_misc) < 0)
1776                 printk(KERN_INFO "btrfs: misc_deregister failed for control device\n");
1777 }
1778
1779 static void btrfs_print_info(void)
1780 {
1781         printk(KERN_INFO "Btrfs loaded"
1782 #ifdef CONFIG_BTRFS_DEBUG
1783                         ", debug=on"
1784 #endif
1785 #ifdef CONFIG_BTRFS_ASSERT
1786                         ", assert=on"
1787 #endif
1788 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1789                         ", integrity-checker=on"
1790 #endif
1791                         "\n");
1792 }
1793
1794 static int btrfs_run_sanity_tests(void)
1795 {
1796         int ret;
1797
1798         ret = btrfs_init_test_fs();
1799         if (ret)
1800                 return ret;
1801
1802         ret = btrfs_test_free_space_cache();
1803         if (ret)
1804                 goto out;
1805         ret = btrfs_test_extent_buffer_operations();
1806         if (ret)
1807                 goto out;
1808         ret = btrfs_test_extent_io();
1809         if (ret)
1810                 goto out;
1811         ret = btrfs_test_inodes();
1812 out:
1813         btrfs_destroy_test_fs();
1814         return ret;
1815 }
1816
1817 static int __init init_btrfs_fs(void)
1818 {
1819         int err;
1820
1821         err = btrfs_init_sysfs();
1822         if (err)
1823                 return err;
1824
1825         btrfs_init_compress();
1826
1827         err = btrfs_init_cachep();
1828         if (err)
1829                 goto free_compress;
1830
1831         err = extent_io_init();
1832         if (err)
1833                 goto free_cachep;
1834
1835         err = extent_map_init();
1836         if (err)
1837                 goto free_extent_io;
1838
1839         err = ordered_data_init();
1840         if (err)
1841                 goto free_extent_map;
1842
1843         err = btrfs_delayed_inode_init();
1844         if (err)
1845                 goto free_ordered_data;
1846
1847         err = btrfs_auto_defrag_init();
1848         if (err)
1849                 goto free_delayed_inode;
1850
1851         err = btrfs_delayed_ref_init();
1852         if (err)
1853                 goto free_auto_defrag;
1854
1855         err = btrfs_prelim_ref_init();
1856         if (err)
1857                 goto free_prelim_ref;
1858
1859         err = btrfs_interface_init();
1860         if (err)
1861                 goto free_delayed_ref;
1862
1863         btrfs_init_lockdep();
1864
1865         btrfs_print_info();
1866
1867         err = btrfs_run_sanity_tests();
1868         if (err)
1869                 goto unregister_ioctl;
1870
1871         err = register_filesystem(&btrfs_fs_type);
1872         if (err)
1873                 goto unregister_ioctl;
1874
1875         return 0;
1876
1877 unregister_ioctl:
1878         btrfs_interface_exit();
1879 free_prelim_ref:
1880         btrfs_prelim_ref_exit();
1881 free_delayed_ref:
1882         btrfs_delayed_ref_exit();
1883 free_auto_defrag:
1884         btrfs_auto_defrag_exit();
1885 free_delayed_inode:
1886         btrfs_delayed_inode_exit();
1887 free_ordered_data:
1888         ordered_data_exit();
1889 free_extent_map:
1890         extent_map_exit();
1891 free_extent_io:
1892         extent_io_exit();
1893 free_cachep:
1894         btrfs_destroy_cachep();
1895 free_compress:
1896         btrfs_exit_compress();
1897         btrfs_exit_sysfs();
1898         return err;
1899 }
1900
1901 static void __exit exit_btrfs_fs(void)
1902 {
1903         btrfs_destroy_cachep();
1904         btrfs_delayed_ref_exit();
1905         btrfs_auto_defrag_exit();
1906         btrfs_delayed_inode_exit();
1907         btrfs_prelim_ref_exit();
1908         ordered_data_exit();
1909         extent_map_exit();
1910         extent_io_exit();
1911         btrfs_interface_exit();
1912         unregister_filesystem(&btrfs_fs_type);
1913         btrfs_exit_sysfs();
1914         btrfs_cleanup_fs_uuids();
1915         btrfs_exit_compress();
1916 }
1917
1918 module_init(init_btrfs_fs)
1919 module_exit(exit_btrfs_fs)
1920
1921 MODULE_LICENSE("GPL");