Pileus Git - ~andy/linux/blob - 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
 156                         "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
 157                         sb->s_id, function, line, errno, errstr, &vaf);
 158                 va_end(args);
 159         } else {
 160                 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
 161                         sb->s_id, function, line, errno, errstr);
 162         }
 163
 164         /* Don't go through full error handling during mount */
 165         save_error_info(fs_info);
 166         if (sb->s_flags & MS_BORN)
 167                 btrfs_handle_error(fs_info);
 168 }
 169
 170 static const char * const logtypes[] = {
 171         "emergency",
 172         "alert",
 173         "critical",
 174         "error",
 175         "warning",
 176         "notice",
 177         "info",
 178         "debug",
 179 };
 180
 181 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
 182 {
 183         struct super_block *sb = fs_info->sb;
 184         char lvl[4];
 185         struct va_format vaf;
 186         va_list args;
 187         const char *type = logtypes[4];
 188         int kern_level;
 189
 190         va_start(args, fmt);
 191
 192         kern_level = printk_get_level(fmt);
 193         if (kern_level) {
 194                 size_t size = printk_skip_level(fmt) - fmt;
 195                 memcpy(lvl, fmt,  size);
 196                 lvl[size] = '\0';
 197                 fmt += size;
 198                 type = logtypes[kern_level - '0'];
 199         } else
 200                 *lvl = '\0';
 201
 202         vaf.fmt = fmt;
 203         vaf.va = &args;
 204
 205         printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
 206
 207         va_end(args);
 208 }
 209
 210 #else
 211
 212 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 213                        unsigned int line, int errno, const char *fmt, ...)
 214 {
 215         struct super_block *sb = fs_info->sb;
 216
 217         /*
 218          * Special case: if the error is EROFS, and we're already
 219          * under MS_RDONLY, then it is safe here.
 220          */
 221         if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
 222                 return;
 223
 224         /* Don't go through full error handling during mount */
 225         if (sb->s_flags & MS_BORN) {
 226                 save_error_info(fs_info);
 227                 btrfs_handle_error(fs_info);
 228         }
 229 }
 230 #endif
 231
 232 /*
 233  * We only mark the transaction aborted and then set the file system read-only.
 234  * This will prevent new transactions from starting or trying to join this
 235  * one.
 236  *
 237  * This means that error recovery at the call site is limited to freeing
 238  * any local memory allocations and passing the error code up without
 239  * further cleanup. The transaction should complete as it normally would
 240  * in the call path but will return -EIO.
 241  *
 242  * We'll complete the cleanup in btrfs_end_transaction and
 243  * btrfs_commit_transaction.
 244  */
 245 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
 246                                struct btrfs_root *root, const char *function,
 247                                unsigned int line, int errno)
 248 {
 249         /*
 250          * Report first abort since mount
 251          */
 252         if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
 253                                 &root->fs_info->fs_state)) {
 254                 WARN(1, KERN_DEBUG "BTRFS: Transaction aborted (error %d)\n",
 255                                 errno);
 256         }
 257         trans->aborted = errno;
 258         /* Nothing used. The other threads that have joined this
 259          * transaction may be able to continue. */
 260         if (!trans->blocks_used) {
 261                 const char *errstr;
 262
 263                 errstr = btrfs_decode_error(errno);
 264                 btrfs_warn(root->fs_info,
 265                            "%s:%d: Aborting unused transaction(%s).",
 266                            function, line, errstr);
 267                 return;
 268         }
 269         ACCESS_ONCE(trans->transaction->aborted) = errno;
 270         /* Wake up anybody who may be waiting on this transaction */
 271         wake_up(&root->fs_info->transaction_wait);
 272         wake_up(&root->fs_info->transaction_blocked_wait);
 273         __btrfs_std_error(root->fs_info, function, line, errno, NULL);
 274 }
 275 /*
 276  * __btrfs_panic decodes unexpected, fatal errors from the caller,
 277  * issues an alert, and either panics or BUGs, depending on mount options.
 278  */
 279 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
 280                    unsigned int line, int errno, const char *fmt, ...)
 281 {
 282         char *s_id = "<unknown>";
 283         const char *errstr;
 284         struct va_format vaf = { .fmt = fmt };
 285         va_list args;
 286
 287         if (fs_info)
 288                 s_id = fs_info->sb->s_id;
 289
 290         va_start(args, fmt);
 291         vaf.va = &args;
 292
 293         errstr = btrfs_decode_error(errno);
 294         if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
 295                 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
 296                         s_id, function, line, &vaf, errno, errstr);
 297
 298         btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
 299                    function, line, &vaf, errno, errstr);
 300         va_end(args);
 301         /* Caller calls BUG() */
 302 }
 303
 304 static void btrfs_put_super(struct super_block *sb)
 305 {
 306         (void)close_ctree(btrfs_sb(sb)->tree_root);
 307         /* FIXME: need to fix VFS to return error? */
 308         /* AV: return it _where_?  ->put_super() can be triggered by any number
 309          * of async events, up to and including delivery of SIGKILL to the
 310          * last process that kept it busy.  Or segfault in the aforementioned
 311          * process...  Whom would you report that to?
 312          */
 313 }
 314
 315 enum {
 316         Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
 317         Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
 318         Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
 319         Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
 320         Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
 321         Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
 322         Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
 323         Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
 324         Opt_check_integrity, Opt_check_integrity_including_extent_data,
 325         Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
 326         Opt_commit_interval,
 327         Opt_err,
 328 };
 329
 330 static match_table_t tokens = {
 331         {Opt_degraded, "degraded"},
 332         {Opt_subvol, "subvol=%s"},
 333         {Opt_subvolid, "subvolid=%s"},
 334         {Opt_device, "device=%s"},
 335         {Opt_nodatasum, "nodatasum"},
 336         {Opt_nodatacow, "nodatacow"},
 337         {Opt_nobarrier, "nobarrier"},
 338         {Opt_max_inline, "max_inline=%s"},
 339         {Opt_alloc_start, "alloc_start=%s"},
 340         {Opt_thread_pool, "thread_pool=%d"},
 341         {Opt_compress, "compress"},
 342         {Opt_compress_type, "compress=%s"},
 343         {Opt_compress_force, "compress-force"},
 344         {Opt_compress_force_type, "compress-force=%s"},
 345         {Opt_ssd, "ssd"},
 346         {Opt_ssd_spread, "ssd_spread"},
 347         {Opt_nossd, "nossd"},
 348         {Opt_noacl, "noacl"},
 349         {Opt_notreelog, "notreelog"},
 350         {Opt_flushoncommit, "flushoncommit"},
 351         {Opt_ratio, "metadata_ratio=%d"},
 352         {Opt_discard, "discard"},
 353         {Opt_space_cache, "space_cache"},
 354         {Opt_clear_cache, "clear_cache"},
 355         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
 356         {Opt_enospc_debug, "enospc_debug"},
 357         {Opt_subvolrootid, "subvolrootid=%d"},
 358         {Opt_defrag, "autodefrag"},
 359         {Opt_inode_cache, "inode_cache"},
 360         {Opt_no_space_cache, "nospace_cache"},
 361         {Opt_recovery, "recovery"},
 362         {Opt_skip_balance, "skip_balance"},
 363         {Opt_check_integrity, "check_int"},
 364         {Opt_check_integrity_including_extent_data, "check_int_data"},
 365         {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
 366         {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
 367         {Opt_fatal_errors, "fatal_errors=%s"},
 368         {Opt_commit_interval, "commit=%d"},
 369         {Opt_err, NULL},
 370 };
 371
 372 /*
 373  * Regular mount options parser.  Everything that is needed only when
 374  * reading in a new superblock is parsed here.
 375  * XXX JDM: This needs to be cleaned up for remount.
 376  */
 377 int btrfs_parse_options(struct btrfs_root *root, char *options)
 378 {
 379         struct btrfs_fs_info *info = root->fs_info;
 380         substring_t args[MAX_OPT_ARGS];
 381         char *p, *num, *orig = NULL;
 382         u64 cache_gen;
 383         int intarg;
 384         int ret = 0;
 385         char *compress_type;
 386         bool compress_force = false;
 387
 388         cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
 389         if (cache_gen)
 390                 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 391
 392         if (!options)
 393                 goto out;
 394
 395         /*
 396          * strsep changes the string, duplicate it because parse_options
 397          * gets called twice
 398          */
 399         options = kstrdup(options, GFP_NOFS);
 400         if (!options)
 401                 return -ENOMEM;
 402
 403         orig = options;
 404
 405         while ((p = strsep(&options, ",")) != NULL) {
 406                 int token;
 407                 if (!*p)
 408                         continue;
 409
 410                 token = match_token(p, tokens, args);
 411                 switch (token) {
 412                 case Opt_degraded:
 413                         btrfs_info(root->fs_info, "allowing degraded mounts");
 414                         btrfs_set_opt(info->mount_opt, DEGRADED);
 415                         break;
 416                 case Opt_subvol:
 417                 case Opt_subvolid:
 418                 case Opt_subvolrootid:
 419                 case Opt_device:
 420                         /*
 421                          * These are parsed by btrfs_parse_early_options
 422                          * and can be happily ignored here.
 423                          */
 424                         break;
 425                 case Opt_nodatasum:
 426                         btrfs_info(root->fs_info, "setting nodatasum");
 427                         btrfs_set_opt(info->mount_opt, NODATASUM);
 428                         break;
 429                 case Opt_nodatacow:
 430                         if (!btrfs_test_opt(root, COMPRESS) ||
 431                                 !btrfs_test_opt(root, FORCE_COMPRESS)) {
 432                                         btrfs_info(root->fs_info,
 433                                                 "setting nodatacow, compression disabled");
 434                         } else {
 435                                 btrfs_info(root->fs_info, "setting nodatacow");
 436                         }
 437                         btrfs_clear_opt(info->mount_opt, COMPRESS);
 438                         btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 439                         btrfs_set_opt(info->mount_opt, NODATACOW);
 440                         btrfs_set_opt(info->mount_opt, NODATASUM);
 441                         break;
 442                 case Opt_compress_force:
 443                 case Opt_compress_force_type:
 444                         compress_force = true;
 445                         /* Fallthrough */
 446                 case Opt_compress:
 447                 case Opt_compress_type:
 448                         if (token == Opt_compress ||
 449                             token == Opt_compress_force ||
 450                             strcmp(args[0].from, "zlib") == 0) {
 451                                 compress_type = "zlib";
 452                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
 453                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 454                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 455                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 456                         } else if (strcmp(args[0].from, "lzo") == 0) {
 457                                 compress_type = "lzo";
 458                                 info->compress_type = BTRFS_COMPRESS_LZO;
 459                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 460                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 461                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 462                                 btrfs_set_fs_incompat(info, COMPRESS_LZO);
 463                         } else if (strncmp(args[0].from, "no", 2) == 0) {
 464                                 compress_type = "no";
 465                                 btrfs_clear_opt(info->mount_opt, COMPRESS);
 466                                 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 467                                 compress_force = false;
 468                         } else {
 469                                 ret = -EINVAL;
 470                                 goto out;
 471                         }
 472
 473                         if (compress_force) {
 474                                 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
 475                                 btrfs_info(root->fs_info, "force %s compression",
 476                                         compress_type);
 477                         } else if (btrfs_test_opt(root, COMPRESS)) {
 478                                 pr_info("btrfs: use %s compression\n",
 479                                         compress_type);
 480                         }
 481                         break;
 482                 case Opt_ssd:
 483                         btrfs_info(root->fs_info, "use ssd allocation scheme");
 484                         btrfs_set_opt(info->mount_opt, SSD);
 485                         break;
 486                 case Opt_ssd_spread:
 487                         btrfs_info(root->fs_info, "use spread ssd allocation scheme");
 488                         btrfs_set_opt(info->mount_opt, SSD);
 489                         btrfs_set_opt(info->mount_opt, SSD_SPREAD);
 490                         break;
 491                 case Opt_nossd:
 492                         btrfs_info(root->fs_info, "not using ssd allocation scheme");
 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                         btrfs_info(root->fs_info, "turning off barriers");
 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                                 btrfs_info(root->fs_info, "max_inline at %llu",
 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                                 btrfs_info(root->fs_info, "allocations start at %llu",
 538                                         info->alloc_start);
 539                         } else {
 540                                 ret = -ENOMEM;
 541                                 goto out;
 542                         }
 543                         break;
 544                 case Opt_noacl:
 545                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
 546                         break;
 547                 case Opt_notreelog:
 548                         btrfs_info(root->fs_info, "disabling tree log");
 549                         btrfs_set_opt(info->mount_opt, NOTREELOG);
 550                         break;
 551                 case Opt_flushoncommit:
 552                         btrfs_info(root->fs_info, "turning on flush-on-commit");
 553                         btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
 554                         break;
 555                 case Opt_ratio:
 556                         ret = match_int(&args[0], &intarg);
 557                         if (ret) {
 558                                 goto out;
 559                         } else if (intarg >= 0) {
 560                                 info->metadata_ratio = intarg;
 561                                 btrfs_info(root->fs_info, "metadata ratio %d",
 562                                        info->metadata_ratio);
 563                         } else {
 564                                 ret = -EINVAL;
 565                                 goto out;
 566                         }
 567                         break;
 568                 case Opt_discard:
 569                         btrfs_set_opt(info->mount_opt, DISCARD);
 570                         break;
 571                 case Opt_space_cache:
 572                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 573                         break;
 574                 case Opt_rescan_uuid_tree:
 575                         btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
 576                         break;
 577                 case Opt_no_space_cache:
 578                         btrfs_info(root->fs_info, "disabling disk space caching");
 579                         btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
 580                         break;
 581                 case Opt_inode_cache:
 582                         btrfs_info(root->fs_info, "enabling inode map caching");
 583                         btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
 584                         break;
 585                 case Opt_clear_cache:
 586                         btrfs_info(root->fs_info, "force clearing of disk cache");
 587                         btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
 588                         break;
 589                 case Opt_user_subvol_rm_allowed:
 590                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
 591                         break;
 592                 case Opt_enospc_debug:
 593                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
 594                         break;
 595                 case Opt_defrag:
 596                         btrfs_info(root->fs_info, "enabling auto defrag");
 597                         btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
 598                         break;
 599                 case Opt_recovery:
 600                         btrfs_info(root->fs_info, "enabling auto recovery");
 601                         btrfs_set_opt(info->mount_opt, RECOVERY);
 602                         break;
 603                 case Opt_skip_balance:
 604                         btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
 605                         break;
 606 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 607                 case Opt_check_integrity_including_extent_data:
 608                         btrfs_info(root->fs_info,
 609                                    "enabling check integrity including extent data");
 610                         btrfs_set_opt(info->mount_opt,
 611                                       CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
 612                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 613                         break;
 614                 case Opt_check_integrity:
 615                         btrfs_info(root->fs_info, "enabling check integrity");
 616                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 617                         break;
 618                 case Opt_check_integrity_print_mask:
 619                         ret = match_int(&args[0], &intarg);
 620                         if (ret) {
 621                                 goto out;
 622                         } else if (intarg >= 0) {
 623                                 info->check_integrity_print_mask = intarg;
 624                                 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
 625                                        info->check_integrity_print_mask);
 626                         } else {
 627                                 ret = -EINVAL;
 628                                 goto out;
 629                         }
 630                         break;
 631 #else
 632                 case Opt_check_integrity_including_extent_data:
 633                 case Opt_check_integrity:
 634                 case Opt_check_integrity_print_mask:
 635                         btrfs_err(root->fs_info,
 636                                 "support for check_integrity* not compiled in!");
 637                         ret = -EINVAL;
 638                         goto out;
 639 #endif
 640                 case Opt_fatal_errors:
 641                         if (strcmp(args[0].from, "panic") == 0)
 642                                 btrfs_set_opt(info->mount_opt,
 643                                               PANIC_ON_FATAL_ERROR);
 644                         else if (strcmp(args[0].from, "bug") == 0)
 645                                 btrfs_clear_opt(info->mount_opt,
 646                                               PANIC_ON_FATAL_ERROR);
 647                         else {
 648                                 ret = -EINVAL;
 649                                 goto out;
 650                         }
 651                         break;
 652                 case Opt_commit_interval:
 653                         intarg = 0;
 654                         ret = match_int(&args[0], &intarg);
 655                         if (ret < 0) {
 656                                 btrfs_err(root->fs_info, "invalid commit interval");
 657                                 ret = -EINVAL;
 658                                 goto out;
 659                         }
 660                         if (intarg > 0) {
 661                                 if (intarg > 300) {
 662                                         btrfs_warn(root->fs_info, "excessive commit interval %d",
 663                                                         intarg);
 664                                 }
 665                                 info->commit_interval = intarg;
 666                         } else {
 667                                 btrfs_info(root->fs_info, "using default commit interval %ds",
 668                                     BTRFS_DEFAULT_COMMIT_INTERVAL);
 669                                 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
 670                         }
 671                         break;
 672                 case Opt_err:
 673                         btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
 674                         ret = -EINVAL;
 675                         goto out;
 676                 default:
 677                         break;
 678                 }
 679         }
 680 out:
 681         if (!ret && btrfs_test_opt(root, SPACE_CACHE))
 682                 btrfs_info(root->fs_info, "disk space caching is enabled");
 683         kfree(orig);
 684         return ret;
 685 }
 686
 687 /*
 688  * Parse mount options that are required early in the mount process.
 689  *
 690  * All other options will be parsed on much later in the mount process and
 691  * only when we need to allocate a new super block.
 692  */
 693 static int btrfs_parse_early_options(const char *options, fmode_t flags,
 694                 void *holder, char **subvol_name, u64 *subvol_objectid,
 695                 struct btrfs_fs_devices **fs_devices)
 696 {
 697         substring_t args[MAX_OPT_ARGS];
 698         char *device_name, *opts, *orig, *p;
 699         char *num = NULL;
 700         int error = 0;
 701
 702         if (!options)
 703                 return 0;
 704
 705         /*
 706          * strsep changes the string, duplicate it because parse_options
 707          * gets called twice
 708          */
 709         opts = kstrdup(options, GFP_KERNEL);
 710         if (!opts)
 711                 return -ENOMEM;
 712         orig = opts;
 713
 714         while ((p = strsep(&opts, ",")) != NULL) {
 715                 int token;
 716                 if (!*p)
 717                         continue;
 718
 719                 token = match_token(p, tokens, args);
 720                 switch (token) {
 721                 case Opt_subvol:
 722                         kfree(*subvol_name);
 723                         *subvol_name = match_strdup(&args[0]);
 724                         if (!*subvol_name) {
 725                                 error = -ENOMEM;
 726                                 goto out;
 727                         }
 728                         break;
 729                 case Opt_subvolid:
 730                         num = match_strdup(&args[0]);
 731                         if (num) {
 732                                 *subvol_objectid = memparse(num, NULL);
 733                                 kfree(num);
 734                                 /* we want the original fs_tree */
 735                                 if (!*subvol_objectid)
 736                                         *subvol_objectid =
 737                                                 BTRFS_FS_TREE_OBJECTID;
 738                         } else {
 739                                 error = -EINVAL;
 740                                 goto out;
 741                         }
 742                         break;
 743                 case Opt_subvolrootid:
 744                         printk(KERN_WARNING
 745                                 "BTRFS: 'subvolrootid' mount option is deprecated and has "
 746                                 "no effect\n");
 747                         break;
 748                 case Opt_device:
 749                         device_name = match_strdup(&args[0]);
 750                         if (!device_name) {
 751                                 error = -ENOMEM;
 752                                 goto out;
 753                         }
 754                         error = btrfs_scan_one_device(device_name,
 755                                         flags, holder, fs_devices);
 756                         kfree(device_name);
 757                         if (error)
 758                                 goto out;
 759                         break;
 760                 default:
 761                         break;
 762                 }
 763         }
 764
 765 out:
 766         kfree(orig);
 767         return error;
 768 }
 769
 770 static struct dentry *get_default_root(struct super_block *sb,
 771                                        u64 subvol_objectid)
 772 {
 773         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 774         struct btrfs_root *root = fs_info->tree_root;
 775         struct btrfs_root *new_root;
 776         struct btrfs_dir_item *di;
 777         struct btrfs_path *path;
 778         struct btrfs_key location;
 779         struct inode *inode;
 780         u64 dir_id;
 781         int new = 0;
 782
 783         /*
 784          * We have a specific subvol we want to mount, just setup location and
 785          * go look up the root.
 786          */
 787         if (subvol_objectid) {
 788                 location.objectid = subvol_objectid;
 789                 location.type = BTRFS_ROOT_ITEM_KEY;
 790                 location.offset = (u64)-1;
 791                 goto find_root;
 792         }
 793
 794         path = btrfs_alloc_path();
 795         if (!path)
 796                 return ERR_PTR(-ENOMEM);
 797         path->leave_spinning = 1;
 798
 799         /*
 800          * Find the "default" dir item which points to the root item that we
 801          * will mount by default if we haven't been given a specific subvolume
 802          * to mount.
 803          */
 804         dir_id = btrfs_super_root_dir(fs_info->super_copy);
 805         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
 806         if (IS_ERR(di)) {
 807                 btrfs_free_path(path);
 808                 return ERR_CAST(di);
 809         }
 810         if (!di) {
 811                 /*
 812                  * Ok the default dir item isn't there.  This is weird since
 813                  * it's always been there, but don't freak out, just try and
 814                  * mount to root most subvolume.
 815                  */
 816                 btrfs_free_path(path);
 817                 dir_id = BTRFS_FIRST_FREE_OBJECTID;
 818                 new_root = fs_info->fs_root;
 819                 goto setup_root;
 820         }
 821
 822         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 823         btrfs_free_path(path);
 824
 825 find_root:
 826         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
 827         if (IS_ERR(new_root))
 828                 return ERR_CAST(new_root);
 829
 830         dir_id = btrfs_root_dirid(&new_root->root_item);
 831 setup_root:
 832         location.objectid = dir_id;
 833         location.type = BTRFS_INODE_ITEM_KEY;
 834         location.offset = 0;
 835
 836         inode = btrfs_iget(sb, &location, new_root, &new);
 837         if (IS_ERR(inode))
 838                 return ERR_CAST(inode);
 839
 840         /*
 841          * If we're just mounting the root most subvol put the inode and return
 842          * a reference to the dentry.  We will have already gotten a reference
 843          * to the inode in btrfs_fill_super so we're good to go.
 844          */
 845         if (!new && sb->s_root->d_inode == inode) {
 846                 iput(inode);
 847                 return dget(sb->s_root);
 848         }
 849
 850         return d_obtain_alias(inode);
 851 }
 852
 853 static int btrfs_fill_super(struct super_block *sb,
 854                             struct btrfs_fs_devices *fs_devices,
 855                             void *data, int silent)
 856 {
 857         struct inode *inode;
 858         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 859         struct btrfs_key key;
 860         int err;
 861
 862         sb->s_maxbytes = MAX_LFS_FILESIZE;
 863         sb->s_magic = BTRFS_SUPER_MAGIC;
 864         sb->s_op = &btrfs_super_ops;
 865         sb->s_d_op = &btrfs_dentry_operations;
 866         sb->s_export_op = &btrfs_export_ops;
 867         sb->s_xattr = btrfs_xattr_handlers;
 868         sb->s_time_gran = 1;
 869 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 870         sb->s_flags |= MS_POSIXACL;
 871 #endif
 872         sb->s_flags |= MS_I_VERSION;
 873         err = open_ctree(sb, fs_devices, (char *)data);
 874         if (err) {
 875                 printk(KERN_ERR "BTRFS: open_ctree failed\n");
 876                 return err;
 877         }
 878
 879         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 880         key.type = BTRFS_INODE_ITEM_KEY;
 881         key.offset = 0;
 882         inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
 883         if (IS_ERR(inode)) {
 884                 err = PTR_ERR(inode);
 885                 goto fail_close;
 886         }
 887
 888         sb->s_root = d_make_root(inode);
 889         if (!sb->s_root) {
 890                 err = -ENOMEM;
 891                 goto fail_close;
 892         }
 893
 894         save_mount_options(sb, data);
 895         cleancache_init_fs(sb);
 896         sb->s_flags |= MS_ACTIVE;
 897         return 0;
 898
 899 fail_close:
 900         close_ctree(fs_info->tree_root);
 901         return err;
 902 }
 903
 904 int btrfs_sync_fs(struct super_block *sb, int wait)
 905 {
 906         struct btrfs_trans_handle *trans;
 907         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 908         struct btrfs_root *root = fs_info->tree_root;
 909
 910         trace_btrfs_sync_fs(wait);
 911
 912         if (!wait) {
 913                 filemap_flush(fs_info->btree_inode->i_mapping);
 914                 return 0;
 915         }
 916
 917         btrfs_wait_ordered_roots(fs_info, -1);
 918
 919         trans = btrfs_attach_transaction_barrier(root);
 920         if (IS_ERR(trans)) {
 921                 /* no transaction, don't bother */
 922                 if (PTR_ERR(trans) == -ENOENT)
 923                         return 0;
 924                 return PTR_ERR(trans);
 925         }
 926         return btrfs_commit_transaction(trans, root);
 927 }
 928
 929 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 930 {
 931         struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
 932         struct btrfs_root *root = info->tree_root;
 933         char *compress_type;
 934
 935         if (btrfs_test_opt(root, DEGRADED))
 936                 seq_puts(seq, ",degraded");
 937         if (btrfs_test_opt(root, NODATASUM))
 938                 seq_puts(seq, ",nodatasum");
 939         if (btrfs_test_opt(root, NODATACOW))
 940                 seq_puts(seq, ",nodatacow");
 941         if (btrfs_test_opt(root, NOBARRIER))
 942                 seq_puts(seq, ",nobarrier");
 943         if (info->max_inline != 8192 * 1024)
 944                 seq_printf(seq, ",max_inline=%llu", info->max_inline);
 945         if (info->alloc_start != 0)
 946                 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
 947         if (info->thread_pool_size !=  min_t(unsigned long,
 948                                              num_online_cpus() + 2, 8))
 949                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
 950         if (btrfs_test_opt(root, COMPRESS)) {
 951                 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
 952                         compress_type = "zlib";
 953                 else
 954                         compress_type = "lzo";
 955                 if (btrfs_test_opt(root, FORCE_COMPRESS))
 956                         seq_printf(seq, ",compress-force=%s", compress_type);
 957                 else
 958                         seq_printf(seq, ",compress=%s", compress_type);
 959         }
 960         if (btrfs_test_opt(root, NOSSD))
 961                 seq_puts(seq, ",nossd");
 962         if (btrfs_test_opt(root, SSD_SPREAD))
 963                 seq_puts(seq, ",ssd_spread");
 964         else if (btrfs_test_opt(root, SSD))
 965                 seq_puts(seq, ",ssd");
 966         if (btrfs_test_opt(root, NOTREELOG))
 967                 seq_puts(seq, ",notreelog");
 968         if (btrfs_test_opt(root, FLUSHONCOMMIT))
 969                 seq_puts(seq, ",flushoncommit");
 970         if (btrfs_test_opt(root, DISCARD))
 971                 seq_puts(seq, ",discard");
 972         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
 973                 seq_puts(seq, ",noacl");
 974         if (btrfs_test_opt(root, SPACE_CACHE))
 975                 seq_puts(seq, ",space_cache");
 976         else
 977                 seq_puts(seq, ",nospace_cache");
 978         if (btrfs_test_opt(root, RESCAN_UUID_TREE))
 979                 seq_puts(seq, ",rescan_uuid_tree");
 980         if (btrfs_test_opt(root, CLEAR_CACHE))
 981                 seq_puts(seq, ",clear_cache");
 982         if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
 983                 seq_puts(seq, ",user_subvol_rm_allowed");
 984         if (btrfs_test_opt(root, ENOSPC_DEBUG))
 985                 seq_puts(seq, ",enospc_debug");
 986         if (btrfs_test_opt(root, AUTO_DEFRAG))
 987                 seq_puts(seq, ",autodefrag");
 988         if (btrfs_test_opt(root, INODE_MAP_CACHE))
 989                 seq_puts(seq, ",inode_cache");
 990         if (btrfs_test_opt(root, SKIP_BALANCE))
 991                 seq_puts(seq, ",skip_balance");
 992         if (btrfs_test_opt(root, RECOVERY))
 993                 seq_puts(seq, ",recovery");
 994 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 995         if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
 996                 seq_puts(seq, ",check_int_data");
 997         else if (btrfs_test_opt(root, CHECK_INTEGRITY))
 998                 seq_puts(seq, ",check_int");
 999         if (info->check_integrity_print_mask)
1000                 seq_printf(seq, ",check_int_print_mask=%d",
1001                                 info->check_integrity_print_mask);
1002 #endif
1003         if (info->metadata_ratio)
1004                 seq_printf(seq, ",metadata_ratio=%d",
1005                                 info->metadata_ratio);
1006         if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1007                 seq_puts(seq, ",fatal_errors=panic");
1008         if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1009                 seq_printf(seq, ",commit=%d", info->commit_interval);
1010         return 0;
1011 }
1012
1013 static int btrfs_test_super(struct super_block *s, void *data)
1014 {
1015         struct btrfs_fs_info *p = data;
1016         struct btrfs_fs_info *fs_info = btrfs_sb(s);
1017
1018         return fs_info->fs_devices == p->fs_devices;
1019 }
1020
1021 static int btrfs_set_super(struct super_block *s, void *data)
1022 {
1023         int err = set_anon_super(s, data);
1024         if (!err)
1025                 s->s_fs_info = data;
1026         return err;
1027 }
1028
1029 /*
1030  * subvolumes are identified by ino 256
1031  */
1032 static inline int is_subvolume_inode(struct inode *inode)
1033 {
1034         if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1035                 return 1;
1036         return 0;
1037 }
1038
1039 /*
1040  * This will strip out the subvol=%s argument for an argument string and add
1041  * subvolid=0 to make sure we get the actual tree root for path walking to the
1042  * subvol we want.
1043  */
1044 static char *setup_root_args(char *args)
1045 {
1046         unsigned len = strlen(args) + 2 + 1;
1047         char *src, *dst, *buf;
1048
1049         /*
1050          * We need the same args as before, but with this substitution:
1051          * s!subvol=[^,]+!subvolid=0!
1052          *
1053          * Since the replacement string is up to 2 bytes longer than the
1054          * original, allocate strlen(args) + 2 + 1 bytes.
1055          */
1056
1057         src = strstr(args, "subvol=");
1058         /* This shouldn't happen, but just in case.. */
1059         if (!src)
1060                 return NULL;
1061
1062         buf = dst = kmalloc(len, GFP_NOFS);
1063         if (!buf)
1064                 return NULL;
1065
1066         /*
1067          * If the subvol= arg is not at the start of the string,
1068          * copy whatever precedes it into buf.
1069          */
1070         if (src != args) {
1071                 *src++ = '\0';
1072                 strcpy(buf, args);
1073                 dst += strlen(args);
1074         }
1075
1076         strcpy(dst, "subvolid=0");
1077         dst += strlen("subvolid=0");
1078
1079         /*
1080          * If there is a "," after the original subvol=... string,
1081          * copy that suffix into our buffer.  Otherwise, we're done.
1082          */
1083         src = strchr(src, ',');
1084         if (src)
1085                 strcpy(dst, src);
1086
1087         return buf;
1088 }
1089
1090 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1091                                    const char *device_name, char *data)
1092 {
1093         struct dentry *root;
1094         struct vfsmount *mnt;
1095         char *newargs;
1096
1097         newargs = setup_root_args(data);
1098         if (!newargs)
1099                 return ERR_PTR(-ENOMEM);
1100         mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1101                              newargs);
1102         kfree(newargs);
1103         if (IS_ERR(mnt))
1104                 return ERR_CAST(mnt);
1105
1106         root = mount_subtree(mnt, subvol_name);
1107
1108         if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1109                 struct super_block *s = root->d_sb;
1110                 dput(root);
1111                 root = ERR_PTR(-EINVAL);
1112                 deactivate_locked_super(s);
1113                 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",
1114                                 subvol_name);
1115         }
1116
1117         return root;
1118 }
1119
1120 /*
1121  * Find a superblock for the given device / mount point.
1122  *
1123  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
1124  *        for multiple device setup.  Make sure to keep it in sync.
1125  */
1126 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1127                 const char *device_name, void *data)
1128 {
1129         struct block_device *bdev = NULL;
1130         struct super_block *s;
1131         struct dentry *root;
1132         struct btrfs_fs_devices *fs_devices = NULL;
1133         struct btrfs_fs_info *fs_info = NULL;
1134         fmode_t mode = FMODE_READ;
1135         char *subvol_name = NULL;
1136         u64 subvol_objectid = 0;
1137         int error = 0;
1138
1139         if (!(flags & MS_RDONLY))
1140                 mode |= FMODE_WRITE;
1141
1142         error = btrfs_parse_early_options(data, mode, fs_type,
1143                                           &subvol_name, &subvol_objectid,
1144                                           &fs_devices);
1145         if (error) {
1146                 kfree(subvol_name);
1147                 return ERR_PTR(error);
1148         }
1149
1150         if (subvol_name) {
1151                 root = mount_subvol(subvol_name, flags, device_name, data);
1152                 kfree(subvol_name);
1153                 return root;
1154         }
1155
1156         error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1157         if (error)
1158                 return ERR_PTR(error);
1159
1160         /*
1161          * Setup a dummy root and fs_info for test/set super.  This is because
1162          * we don't actually fill this stuff out until open_ctree, but we need
1163          * it for searching for existing supers, so this lets us do that and
1164          * then open_ctree will properly initialize everything later.
1165          */
1166         fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1167         if (!fs_info)
1168                 return ERR_PTR(-ENOMEM);
1169
1170         fs_info->fs_devices = fs_devices;
1171
1172         fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1173         fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1174         if (!fs_info->super_copy || !fs_info->super_for_commit) {
1175                 error = -ENOMEM;
1176                 goto error_fs_info;
1177         }
1178
1179         error = btrfs_open_devices(fs_devices, mode, fs_type);
1180         if (error)
1181                 goto error_fs_info;
1182
1183         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1184                 error = -EACCES;
1185                 goto error_close_devices;
1186         }
1187
1188         bdev = fs_devices->latest_bdev;
1189         s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1190                  fs_info);
1191         if (IS_ERR(s)) {
1192                 error = PTR_ERR(s);
1193                 goto error_close_devices;
1194         }
1195
1196         if (s->s_root) {
1197                 btrfs_close_devices(fs_devices);
1198                 free_fs_info(fs_info);
1199                 if ((flags ^ s->s_flags) & MS_RDONLY)
1200                         error = -EBUSY;
1201         } else {
1202                 char b[BDEVNAME_SIZE];
1203
1204                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1205                 btrfs_sb(s)->bdev_holder = fs_type;
1206                 error = btrfs_fill_super(s, fs_devices, data,
1207                                          flags & MS_SILENT ? 1 : 0);
1208         }
1209
1210         root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1211         if (IS_ERR(root))
1212                 deactivate_locked_super(s);
1213
1214         return root;
1215
1216 error_close_devices:
1217         btrfs_close_devices(fs_devices);
1218 error_fs_info:
1219         free_fs_info(fs_info);
1220         return ERR_PTR(error);
1221 }
1222
1223 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1224 {
1225         spin_lock_irq(&workers->lock);
1226         workers->max_workers = new_limit;
1227         spin_unlock_irq(&workers->lock);
1228 }
1229
1230 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1231                                      int new_pool_size, int old_pool_size)
1232 {
1233         if (new_pool_size == old_pool_size)
1234                 return;
1235
1236         fs_info->thread_pool_size = new_pool_size;
1237
1238         btrfs_info(fs_info, "resize thread pool %d -> %d",
1239                old_pool_size, new_pool_size);
1240
1241         btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1242         btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1243         btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1244         btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1245         btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1246         btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1247         btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1248         btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1249         btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1250         btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1251         btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1252         btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1253         btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1254         btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1255                               new_pool_size);
1256 }
1257
1258 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1259 {
1260         set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1261 }
1262
1263 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1264                                        unsigned long old_opts, int flags)
1265 {
1266         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1267             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1268              (flags & MS_RDONLY))) {
1269                 /* wait for any defraggers to finish */
1270                 wait_event(fs_info->transaction_wait,
1271                            (atomic_read(&fs_info->defrag_running) == 0));
1272                 if (flags & MS_RDONLY)
1273                         sync_filesystem(fs_info->sb);
1274         }
1275 }
1276
1277 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1278                                          unsigned long old_opts)
1279 {
1280         /*
1281          * We need cleanup all defragable inodes if the autodefragment is
1282          * close or the fs is R/O.
1283          */
1284         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1285             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1286              (fs_info->sb->s_flags & MS_RDONLY))) {
1287                 btrfs_cleanup_defrag_inodes(fs_info);
1288         }
1289
1290         clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1291 }
1292
1293 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1294 {
1295         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1296         struct btrfs_root *root = fs_info->tree_root;
1297         unsigned old_flags = sb->s_flags;
1298         unsigned long old_opts = fs_info->mount_opt;
1299         unsigned long old_compress_type = fs_info->compress_type;
1300         u64 old_max_inline = fs_info->max_inline;
1301         u64 old_alloc_start = fs_info->alloc_start;
1302         int old_thread_pool_size = fs_info->thread_pool_size;
1303         unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1304         int ret;
1305
1306         btrfs_remount_prepare(fs_info);
1307
1308         ret = btrfs_parse_options(root, data);
1309         if (ret) {
1310                 ret = -EINVAL;
1311                 goto restore;
1312         }
1313
1314         btrfs_remount_begin(fs_info, old_opts, *flags);
1315         btrfs_resize_thread_pool(fs_info,
1316                 fs_info->thread_pool_size, old_thread_pool_size);
1317
1318         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1319                 goto out;
1320
1321         if (*flags & MS_RDONLY) {
1322                 /*
1323                  * this also happens on 'umount -rf' or on shutdown, when
1324                  * the filesystem is busy.
1325                  */
1326
1327                 /* wait for the uuid_scan task to finish */
1328                 down(&fs_info->uuid_tree_rescan_sem);
1329                 /* avoid complains from lockdep et al. */
1330                 up(&fs_info->uuid_tree_rescan_sem);
1331
1332                 sb->s_flags |= MS_RDONLY;
1333
1334                 btrfs_dev_replace_suspend_for_unmount(fs_info);
1335                 btrfs_scrub_cancel(fs_info);
1336                 btrfs_pause_balance(fs_info);
1337
1338                 ret = btrfs_commit_super(root);
1339                 if (ret)
1340                         goto restore;
1341         } else {
1342                 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1343                         btrfs_err(fs_info,
1344                                 "Remounting read-write after error is not allowed");
1345                         ret = -EINVAL;
1346                         goto restore;
1347                 }
1348                 if (fs_info->fs_devices->rw_devices == 0) {
1349                         ret = -EACCES;
1350                         goto restore;
1351                 }
1352
1353                 if (fs_info->fs_devices->missing_devices >
1354                      fs_info->num_tolerated_disk_barrier_failures &&
1355                     !(*flags & MS_RDONLY)) {
1356                         btrfs_warn(fs_info,
1357                                 "too many missing devices, writeable remount is not allowed");
1358                         ret = -EACCES;
1359                         goto restore;
1360                 }
1361
1362                 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1363                         ret = -EINVAL;
1364                         goto restore;
1365                 }
1366
1367                 ret = btrfs_cleanup_fs_roots(fs_info);
1368                 if (ret)
1369                         goto restore;
1370
1371                 /* recover relocation */
1372                 ret = btrfs_recover_relocation(root);
1373                 if (ret)
1374                         goto restore;
1375
1376                 ret = btrfs_resume_balance_async(fs_info);
1377                 if (ret)
1378                         goto restore;
1379
1380                 ret = btrfs_resume_dev_replace_async(fs_info);
1381                 if (ret) {
1382                         btrfs_warn(fs_info, "failed to resume dev_replace");
1383                         goto restore;
1384                 }
1385
1386                 if (!fs_info->uuid_root) {
1387                         btrfs_info(fs_info, "creating UUID tree");
1388                         ret = btrfs_create_uuid_tree(fs_info);
1389                         if (ret) {
1390                                 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1391                                 goto restore;
1392                         }
1393                 }
1394                 sb->s_flags &= ~MS_RDONLY;
1395         }
1396 out:
1397         btrfs_remount_cleanup(fs_info, old_opts);
1398         return 0;
1399
1400 restore:
1401         /* We've hit an error - don't reset MS_RDONLY */
1402         if (sb->s_flags & MS_RDONLY)
1403                 old_flags |= MS_RDONLY;
1404         sb->s_flags = old_flags;
1405         fs_info->mount_opt = old_opts;
1406         fs_info->compress_type = old_compress_type;
1407         fs_info->max_inline = old_max_inline;
1408         mutex_lock(&fs_info->chunk_mutex);
1409         fs_info->alloc_start = old_alloc_start;
1410         mutex_unlock(&fs_info->chunk_mutex);
1411         btrfs_resize_thread_pool(fs_info,
1412                 old_thread_pool_size, fs_info->thread_pool_size);
1413         fs_info->metadata_ratio = old_metadata_ratio;
1414         btrfs_remount_cleanup(fs_info, old_opts);
1415         return ret;
1416 }
1417
1418 /* Used to sort the devices by max_avail(descending sort) */
1419 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1420                                        const void *dev_info2)
1421 {
1422         if (((struct btrfs_device_info *)dev_info1)->max_avail >
1423             ((struct btrfs_device_info *)dev_info2)->max_avail)
1424                 return -1;
1425         else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1426                  ((struct btrfs_device_info *)dev_info2)->max_avail)
1427                 return 1;
1428         else
1429         return 0;
1430 }
1431
1432 /*
1433  * sort the devices by max_avail, in which max free extent size of each device
1434  * is stored.(Descending Sort)
1435  */
1436 static inline void btrfs_descending_sort_devices(
1437                                         struct btrfs_device_info *devices,
1438                                         size_t nr_devices)
1439 {
1440         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1441              btrfs_cmp_device_free_bytes, NULL);
1442 }
1443
1444 /*
1445  * The helper to calc the free space on the devices that can be used to store
1446  * file data.
1447  */
1448 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1449 {
1450         struct btrfs_fs_info *fs_info = root->fs_info;
1451         struct btrfs_device_info *devices_info;
1452         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1453         struct btrfs_device *device;
1454         u64 skip_space;
1455         u64 type;
1456         u64 avail_space;
1457         u64 used_space;
1458         u64 min_stripe_size;
1459         int min_stripes = 1, num_stripes = 1;
1460         int i = 0, nr_devices;
1461         int ret;
1462
1463         nr_devices = fs_info->fs_devices->open_devices;
1464         BUG_ON(!nr_devices);
1465
1466         devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1467                                GFP_NOFS);
1468         if (!devices_info)
1469                 return -ENOMEM;
1470
1471         /* calc min stripe number for data space alloction */
1472         type = btrfs_get_alloc_profile(root, 1);
1473         if (type & BTRFS_BLOCK_GROUP_RAID0) {
1474                 min_stripes = 2;
1475                 num_stripes = nr_devices;
1476         } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1477                 min_stripes = 2;
1478                 num_stripes = 2;
1479         } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1480                 min_stripes = 4;
1481                 num_stripes = 4;
1482         }
1483
1484         if (type & BTRFS_BLOCK_GROUP_DUP)
1485                 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1486         else
1487                 min_stripe_size = BTRFS_STRIPE_LEN;
1488
1489         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1490                 if (!device->in_fs_metadata || !device->bdev ||
1491                     device->is_tgtdev_for_dev_replace)
1492                         continue;
1493
1494                 avail_space = device->total_bytes - device->bytes_used;
1495
1496                 /* align with stripe_len */
1497                 do_div(avail_space, BTRFS_STRIPE_LEN);
1498                 avail_space *= BTRFS_STRIPE_LEN;
1499
1500                 /*
1501                  * In order to avoid overwritting the superblock on the drive,
1502                  * btrfs starts at an offset of at least 1MB when doing chunk
1503                  * allocation.
1504                  */
1505                 skip_space = 1024 * 1024;
1506
1507                 /* user can set the offset in fs_info->alloc_start. */
1508                 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1509                     device->total_bytes)
1510                         skip_space = max(fs_info->alloc_start, skip_space);
1511
1512                 /*
1513                  * btrfs can not use the free space in [0, skip_space - 1],
1514                  * we must subtract it from the total. In order to implement
1515                  * it, we account the used space in this range first.
1516                  */
1517                 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1518                                                      &used_space);
1519                 if (ret) {
1520                         kfree(devices_info);
1521                         return ret;
1522                 }
1523
1524                 /* calc the free space in [0, skip_space - 1] */
1525                 skip_space -= used_space;
1526
1527                 /*
1528                  * we can use the free space in [0, skip_space - 1], subtract
1529                  * it from the total.
1530                  */
1531                 if (avail_space && avail_space >= skip_space)
1532                         avail_space -= skip_space;
1533                 else
1534                         avail_space = 0;
1535
1536                 if (avail_space < min_stripe_size)
1537                         continue;
1538
1539                 devices_info[i].dev = device;
1540                 devices_info[i].max_avail = avail_space;
1541
1542                 i++;
1543         }
1544
1545         nr_devices = i;
1546
1547         btrfs_descending_sort_devices(devices_info, nr_devices);
1548
1549         i = nr_devices - 1;
1550         avail_space = 0;
1551         while (nr_devices >= min_stripes) {
1552                 if (num_stripes > nr_devices)
1553                         num_stripes = nr_devices;
1554
1555                 if (devices_info[i].max_avail >= min_stripe_size) {
1556                         int j;
1557                         u64 alloc_size;
1558
1559                         avail_space += devices_info[i].max_avail * num_stripes;
1560                         alloc_size = devices_info[i].max_avail;
1561                         for (j = i + 1 - num_stripes; j <= i; j++)
1562                                 devices_info[j].max_avail -= alloc_size;
1563                 }
1564                 i--;
1565                 nr_devices--;
1566         }
1567
1568         kfree(devices_info);
1569         *free_bytes = avail_space;
1570         return 0;
1571 }
1572
1573 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1574 {
1575         struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1576         struct btrfs_super_block *disk_super = fs_info->super_copy;
1577         struct list_head *head = &fs_info->space_info;
1578         struct btrfs_space_info *found;
1579         u64 total_used = 0;
1580         u64 total_free_data = 0;
1581         int bits = dentry->d_sb->s_blocksize_bits;
1582         __be32 *fsid = (__be32 *)fs_info->fsid;
1583         int ret;
1584
1585         /* holding chunk_muext to avoid allocating new chunks */
1586         mutex_lock(&fs_info->chunk_mutex);
1587         rcu_read_lock();
1588         list_for_each_entry_rcu(found, head, list) {
1589                 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1590                         total_free_data += found->disk_total - found->disk_used;
1591                         total_free_data -=
1592                                 btrfs_account_ro_block_groups_free_space(found);
1593                 }
1594
1595                 total_used += found->disk_used;
1596         }
1597         rcu_read_unlock();
1598
1599         buf->f_namelen = BTRFS_NAME_LEN;
1600         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1601         buf->f_bfree = buf->f_blocks - (total_used >> bits);
1602         buf->f_bsize = dentry->d_sb->s_blocksize;
1603         buf->f_type = BTRFS_SUPER_MAGIC;
1604         buf->f_bavail = total_free_data;
1605         ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1606         if (ret) {
1607                 mutex_unlock(&fs_info->chunk_mutex);
1608                 return ret;
1609         }
1610         buf->f_bavail += total_free_data;
1611         buf->f_bavail = buf->f_bavail >> bits;
1612         mutex_unlock(&fs_info->chunk_mutex);
1613
1614         /* We treat it as constant endianness (it doesn't matter _which_)
1615            because we want the fsid to come out the same whether mounted
1616            on a big-endian or little-endian host */
1617         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1618         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1619         /* Mask in the root object ID too, to disambiguate subvols */
1620         buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1621         buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1622
1623         return 0;
1624 }
1625
1626 static void btrfs_kill_super(struct super_block *sb)
1627 {
1628         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1629         kill_anon_super(sb);
1630         free_fs_info(fs_info);
1631 }
1632
1633 static struct file_system_type btrfs_fs_type = {
1634         .owner          = THIS_MODULE,
1635         .name           = "btrfs",
1636         .mount          = btrfs_mount,
1637         .kill_sb        = btrfs_kill_super,
1638         .fs_flags       = FS_REQUIRES_DEV,
1639 };
1640 MODULE_ALIAS_FS("btrfs");
1641
1642 /*
1643  * used by btrfsctl to scan devices when no FS is mounted
1644  */
1645 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1646                                 unsigned long arg)
1647 {
1648         struct btrfs_ioctl_vol_args *vol;
1649         struct btrfs_fs_devices *fs_devices;
1650         int ret = -ENOTTY;
1651
1652         if (!capable(CAP_SYS_ADMIN))
1653                 return -EPERM;
1654
1655         vol = memdup_user((void __user *)arg, sizeof(*vol));
1656         if (IS_ERR(vol))
1657                 return PTR_ERR(vol);
1658
1659         switch (cmd) {
1660         case BTRFS_IOC_SCAN_DEV:
1661                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1662                                             &btrfs_fs_type, &fs_devices);
1663                 break;
1664         case BTRFS_IOC_DEVICES_READY:
1665                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1666                                             &btrfs_fs_type, &fs_devices);
1667                 if (ret)
1668                         break;
1669                 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1670                 break;
1671         }
1672
1673         kfree(vol);
1674         return ret;
1675 }
1676
1677 static int btrfs_freeze(struct super_block *sb)
1678 {
1679         struct btrfs_trans_handle *trans;
1680         struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1681
1682         trans = btrfs_attach_transaction_barrier(root);
1683         if (IS_ERR(trans)) {
1684                 /* no transaction, don't bother */
1685                 if (PTR_ERR(trans) == -ENOENT)
1686                         return 0;
1687                 return PTR_ERR(trans);
1688         }
1689         return btrfs_commit_transaction(trans, root);
1690 }
1691
1692 static int btrfs_unfreeze(struct super_block *sb)
1693 {
1694         return 0;
1695 }
1696
1697 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1698 {
1699         struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1700         struct btrfs_fs_devices *cur_devices;
1701         struct btrfs_device *dev, *first_dev = NULL;
1702         struct list_head *head;
1703         struct rcu_string *name;
1704
1705         mutex_lock(&fs_info->fs_devices->device_list_mutex);
1706         cur_devices = fs_info->fs_devices;
1707         while (cur_devices) {
1708                 head = &cur_devices->devices;
1709                 list_for_each_entry(dev, head, dev_list) {
1710                         if (dev->missing)
1711                                 continue;
1712                         if (!first_dev || dev->devid < first_dev->devid)
1713                                 first_dev = dev;
1714                 }
1715                 cur_devices = cur_devices->seed;
1716         }
1717
1718         if (first_dev) {
1719                 rcu_read_lock();
1720                 name = rcu_dereference(first_dev->name);
1721                 seq_escape(m, name->str, " \t\n\\");
1722                 rcu_read_unlock();
1723         } else {
1724                 WARN_ON(1);
1725         }
1726         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1727         return 0;
1728 }
1729
1730 static const struct super_operations btrfs_super_ops = {
1731         .drop_inode     = btrfs_drop_inode,
1732         .evict_inode    = btrfs_evict_inode,
1733         .put_super      = btrfs_put_super,
1734         .sync_fs        = btrfs_sync_fs,
1735         .show_options   = btrfs_show_options,
1736         .show_devname   = btrfs_show_devname,
1737         .write_inode    = btrfs_write_inode,
1738         .alloc_inode    = btrfs_alloc_inode,
1739         .destroy_inode  = btrfs_destroy_inode,
1740         .statfs         = btrfs_statfs,
1741         .remount_fs     = btrfs_remount,
1742         .freeze_fs      = btrfs_freeze,
1743         .unfreeze_fs    = btrfs_unfreeze,
1744 };
1745
1746 static const struct file_operations btrfs_ctl_fops = {
1747         .unlocked_ioctl  = btrfs_control_ioctl,
1748         .compat_ioctl = btrfs_control_ioctl,
1749         .owner   = THIS_MODULE,
1750         .llseek = noop_llseek,
1751 };
1752
1753 static struct miscdevice btrfs_misc = {
1754         .minor          = BTRFS_MINOR,
1755         .name           = "btrfs-control",
1756         .fops           = &btrfs_ctl_fops
1757 };
1758
1759 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1760 MODULE_ALIAS("devname:btrfs-control");
1761
1762 static int btrfs_interface_init(void)
1763 {
1764         return misc_register(&btrfs_misc);
1765 }
1766
1767 static void btrfs_interface_exit(void)
1768 {
1769         if (misc_deregister(&btrfs_misc) < 0)
1770                 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
1771 }
1772
1773 static void btrfs_print_info(void)
1774 {
1775         printk(KERN_INFO "Btrfs loaded"
1776 #ifdef CONFIG_BTRFS_DEBUG
1777                         ", debug=on"
1778 #endif
1779 #ifdef CONFIG_BTRFS_ASSERT
1780                         ", assert=on"
1781 #endif
1782 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1783                         ", integrity-checker=on"
1784 #endif
1785                         "\n");
1786 }
1787
1788 static int btrfs_run_sanity_tests(void)
1789 {
1790         int ret;
1791
1792         ret = btrfs_init_test_fs();
1793         if (ret)
1794                 return ret;
1795
1796         ret = btrfs_test_free_space_cache();
1797         if (ret)
1798                 goto out;
1799         ret = btrfs_test_extent_buffer_operations();
1800         if (ret)
1801                 goto out;
1802         ret = btrfs_test_extent_io();
1803         if (ret)
1804                 goto out;
1805         ret = btrfs_test_inodes();
1806 out:
1807         btrfs_destroy_test_fs();
1808         return ret;
1809 }
1810
1811 static int __init init_btrfs_fs(void)
1812 {
1813         int err;
1814
1815         err = btrfs_init_sysfs();
1816         if (err)
1817                 return err;
1818
1819         btrfs_init_compress();
1820
1821         err = btrfs_init_cachep();
1822         if (err)
1823                 goto free_compress;
1824
1825         err = extent_io_init();
1826         if (err)
1827                 goto free_cachep;
1828
1829         err = extent_map_init();
1830         if (err)
1831                 goto free_extent_io;
1832
1833         err = ordered_data_init();
1834         if (err)
1835                 goto free_extent_map;
1836
1837         err = btrfs_delayed_inode_init();
1838         if (err)
1839                 goto free_ordered_data;
1840
1841         err = btrfs_auto_defrag_init();
1842         if (err)
1843                 goto free_delayed_inode;
1844
1845         err = btrfs_delayed_ref_init();
1846         if (err)
1847                 goto free_auto_defrag;
1848
1849         err = btrfs_prelim_ref_init();
1850         if (err)
1851                 goto free_prelim_ref;
1852
1853         err = btrfs_interface_init();
1854         if (err)
1855                 goto free_delayed_ref;
1856
1857         btrfs_init_lockdep();
1858
1859         btrfs_print_info();
1860
1861         err = btrfs_run_sanity_tests();
1862         if (err)
1863                 goto unregister_ioctl;
1864
1865         err = register_filesystem(&btrfs_fs_type);
1866         if (err)
1867                 goto unregister_ioctl;
1868
1869         return 0;
1870
1871 unregister_ioctl:
1872         btrfs_interface_exit();
1873 free_prelim_ref:
1874         btrfs_prelim_ref_exit();
1875 free_delayed_ref:
1876         btrfs_delayed_ref_exit();
1877 free_auto_defrag:
1878         btrfs_auto_defrag_exit();
1879 free_delayed_inode:
1880         btrfs_delayed_inode_exit();
1881 free_ordered_data:
1882         ordered_data_exit();
1883 free_extent_map:
1884         extent_map_exit();
1885 free_extent_io:
1886         extent_io_exit();
1887 free_cachep:
1888         btrfs_destroy_cachep();
1889 free_compress:
1890         btrfs_exit_compress();
1891         btrfs_exit_sysfs();
1892         return err;
1893 }
1894
1895 static void __exit exit_btrfs_fs(void)
1896 {
1897         btrfs_destroy_cachep();
1898         btrfs_delayed_ref_exit();
1899         btrfs_auto_defrag_exit();
1900         btrfs_delayed_inode_exit();
1901         btrfs_prelim_ref_exit();
1902         ordered_data_exit();
1903         extent_map_exit();
1904         extent_io_exit();
1905         btrfs_interface_exit();
1906         unregister_filesystem(&btrfs_fs_type);
1907         btrfs_exit_sysfs();
1908         btrfs_cleanup_fs_uuids();
1909         btrfs_exit_compress();
1910 }
1911
1912 module_init(init_btrfs_fs)
1913 module_exit(exit_btrfs_fs)
1914
1915 MODULE_LICENSE("GPL");