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, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
 327         Opt_noenospc_debug,
 328         Opt_err,
 329 };
 330
 331 static match_table_t tokens = {
 332         {Opt_degraded, "degraded"},
 333         {Opt_subvol, "subvol=%s"},
 334         {Opt_subvolid, "subvolid=%s"},
 335         {Opt_device, "device=%s"},
 336         {Opt_nodatasum, "nodatasum"},
 337         {Opt_nodatacow, "nodatacow"},
 338         {Opt_nobarrier, "nobarrier"},
 339         {Opt_barrier, "barrier"},
 340         {Opt_max_inline, "max_inline=%s"},
 341         {Opt_alloc_start, "alloc_start=%s"},
 342         {Opt_thread_pool, "thread_pool=%d"},
 343         {Opt_compress, "compress"},
 344         {Opt_compress_type, "compress=%s"},
 345         {Opt_compress_force, "compress-force"},
 346         {Opt_compress_force_type, "compress-force=%s"},
 347         {Opt_ssd, "ssd"},
 348         {Opt_ssd_spread, "ssd_spread"},
 349         {Opt_nossd, "nossd"},
 350         {Opt_noacl, "noacl"},
 351         {Opt_notreelog, "notreelog"},
 352         {Opt_flushoncommit, "flushoncommit"},
 353         {Opt_ratio, "metadata_ratio=%d"},
 354         {Opt_discard, "discard"},
 355         {Opt_nodiscard, "nodiscard"},
 356         {Opt_space_cache, "space_cache"},
 357         {Opt_clear_cache, "clear_cache"},
 358         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
 359         {Opt_enospc_debug, "enospc_debug"},
 360         {Opt_noenospc_debug, "noenospc_debug"},
 361         {Opt_subvolrootid, "subvolrootid=%d"},
 362         {Opt_defrag, "autodefrag"},
 363         {Opt_nodefrag, "noautodefrag"},
 364         {Opt_inode_cache, "inode_cache"},
 365         {Opt_no_space_cache, "nospace_cache"},
 366         {Opt_recovery, "recovery"},
 367         {Opt_skip_balance, "skip_balance"},
 368         {Opt_check_integrity, "check_int"},
 369         {Opt_check_integrity_including_extent_data, "check_int_data"},
 370         {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
 371         {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
 372         {Opt_fatal_errors, "fatal_errors=%s"},
 373         {Opt_commit_interval, "commit=%d"},
 374         {Opt_err, NULL},
 375 };
 376
 377 /*
 378  * Regular mount options parser.  Everything that is needed only when
 379  * reading in a new superblock is parsed here.
 380  * XXX JDM: This needs to be cleaned up for remount.
 381  */
 382 int btrfs_parse_options(struct btrfs_root *root, char *options)
 383 {
 384         struct btrfs_fs_info *info = root->fs_info;
 385         substring_t args[MAX_OPT_ARGS];
 386         char *p, *num, *orig = NULL;
 387         u64 cache_gen;
 388         int intarg;
 389         int ret = 0;
 390         char *compress_type;
 391         bool compress_force = false;
 392
 393         cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
 394         if (cache_gen)
 395                 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 396
 397         if (!options)
 398                 goto out;
 399
 400         /*
 401          * strsep changes the string, duplicate it because parse_options
 402          * gets called twice
 403          */
 404         options = kstrdup(options, GFP_NOFS);
 405         if (!options)
 406                 return -ENOMEM;
 407
 408         orig = options;
 409
 410         while ((p = strsep(&options, ",")) != NULL) {
 411                 int token;
 412                 if (!*p)
 413                         continue;
 414
 415                 token = match_token(p, tokens, args);
 416                 switch (token) {
 417                 case Opt_degraded:
 418                         btrfs_info(root->fs_info, "allowing degraded mounts");
 419                         btrfs_set_opt(info->mount_opt, DEGRADED);
 420                         break;
 421                 case Opt_subvol:
 422                 case Opt_subvolid:
 423                 case Opt_subvolrootid:
 424                 case Opt_device:
 425                         /*
 426                          * These are parsed by btrfs_parse_early_options
 427                          * and can be happily ignored here.
 428                          */
 429                         break;
 430                 case Opt_nodatasum:
 431                         btrfs_info(root->fs_info, "setting nodatasum");
 432                         btrfs_set_opt(info->mount_opt, NODATASUM);
 433                         break;
 434                 case Opt_nodatacow:
 435                         if (!btrfs_test_opt(root, COMPRESS) ||
 436                                 !btrfs_test_opt(root, FORCE_COMPRESS)) {
 437                                         btrfs_info(root->fs_info,
 438                                                 "setting nodatacow, compression disabled");
 439                         } else {
 440                                 btrfs_info(root->fs_info, "setting nodatacow");
 441                         }
 442                         btrfs_clear_opt(info->mount_opt, COMPRESS);
 443                         btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 444                         btrfs_set_opt(info->mount_opt, NODATACOW);
 445                         btrfs_set_opt(info->mount_opt, NODATASUM);
 446                         break;
 447                 case Opt_compress_force:
 448                 case Opt_compress_force_type:
 449                         compress_force = true;
 450                         /* Fallthrough */
 451                 case Opt_compress:
 452                 case Opt_compress_type:
 453                         if (token == Opt_compress ||
 454                             token == Opt_compress_force ||
 455                             strcmp(args[0].from, "zlib") == 0) {
 456                                 compress_type = "zlib";
 457                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
 458                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 459                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 460                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 461                         } else if (strcmp(args[0].from, "lzo") == 0) {
 462                                 compress_type = "lzo";
 463                                 info->compress_type = BTRFS_COMPRESS_LZO;
 464                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 465                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 466                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 467                                 btrfs_set_fs_incompat(info, COMPRESS_LZO);
 468                         } else if (strncmp(args[0].from, "no", 2) == 0) {
 469                                 compress_type = "no";
 470                                 btrfs_clear_opt(info->mount_opt, COMPRESS);
 471                                 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 472                                 compress_force = false;
 473                         } else {
 474                                 ret = -EINVAL;
 475                                 goto out;
 476                         }
 477
 478                         if (compress_force) {
 479                                 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
 480                                 btrfs_info(root->fs_info, "force %s compression",
 481                                         compress_type);
 482                         } else if (btrfs_test_opt(root, COMPRESS)) {
 483                                 pr_info("btrfs: use %s compression\n",
 484                                         compress_type);
 485                         }
 486                         break;
 487                 case Opt_ssd:
 488                         btrfs_info(root->fs_info, "use ssd allocation scheme");
 489                         btrfs_set_opt(info->mount_opt, SSD);
 490                         break;
 491                 case Opt_ssd_spread:
 492                         btrfs_info(root->fs_info, "use spread ssd allocation scheme");
 493                         btrfs_set_opt(info->mount_opt, SSD);
 494                         btrfs_set_opt(info->mount_opt, SSD_SPREAD);
 495                         break;
 496                 case Opt_nossd:
 497                         btrfs_info(root->fs_info, "not using ssd allocation scheme");
 498                         btrfs_set_opt(info->mount_opt, NOSSD);
 499                         btrfs_clear_opt(info->mount_opt, SSD);
 500                         btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
 501                         break;
 502                 case Opt_barrier:
 503                         if (btrfs_test_opt(root, NOBARRIER))
 504                                 btrfs_info(root->fs_info, "turning on barriers");
 505                         btrfs_clear_opt(info->mount_opt, NOBARRIER);
 506                         break;
 507                 case Opt_nobarrier:
 508                         btrfs_info(root->fs_info, "turning off barriers");
 509                         btrfs_set_opt(info->mount_opt, NOBARRIER);
 510                         break;
 511                 case Opt_thread_pool:
 512                         ret = match_int(&args[0], &intarg);
 513                         if (ret) {
 514                                 goto out;
 515                         } else if (intarg > 0) {
 516                                 info->thread_pool_size = intarg;
 517                         } else {
 518                                 ret = -EINVAL;
 519                                 goto out;
 520                         }
 521                         break;
 522                 case Opt_max_inline:
 523                         num = match_strdup(&args[0]);
 524                         if (num) {
 525                                 info->max_inline = memparse(num, NULL);
 526                                 kfree(num);
 527
 528                                 if (info->max_inline) {
 529                                         info->max_inline = max_t(u64,
 530                                                 info->max_inline,
 531                                                 root->sectorsize);
 532                                 }
 533                                 btrfs_info(root->fs_info, "max_inline at %llu",
 534                                         info->max_inline);
 535                         } else {
 536                                 ret = -ENOMEM;
 537                                 goto out;
 538                         }
 539                         break;
 540                 case Opt_alloc_start:
 541                         num = match_strdup(&args[0]);
 542                         if (num) {
 543                                 mutex_lock(&info->chunk_mutex);
 544                                 info->alloc_start = memparse(num, NULL);
 545                                 mutex_unlock(&info->chunk_mutex);
 546                                 kfree(num);
 547                                 btrfs_info(root->fs_info, "allocations start at %llu",
 548                                         info->alloc_start);
 549                         } else {
 550                                 ret = -ENOMEM;
 551                                 goto out;
 552                         }
 553                         break;
 554                 case Opt_noacl:
 555                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
 556                         break;
 557                 case Opt_notreelog:
 558                         btrfs_info(root->fs_info, "disabling tree log");
 559                         btrfs_set_opt(info->mount_opt, NOTREELOG);
 560                         break;
 561                 case Opt_flushoncommit:
 562                         btrfs_info(root->fs_info, "turning on flush-on-commit");
 563                         btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
 564                         break;
 565                 case Opt_ratio:
 566                         ret = match_int(&args[0], &intarg);
 567                         if (ret) {
 568                                 goto out;
 569                         } else if (intarg >= 0) {
 570                                 info->metadata_ratio = intarg;
 571                                 btrfs_info(root->fs_info, "metadata ratio %d",
 572                                        info->metadata_ratio);
 573                         } else {
 574                                 ret = -EINVAL;
 575                                 goto out;
 576                         }
 577                         break;
 578                 case Opt_discard:
 579                         btrfs_set_opt(info->mount_opt, DISCARD);
 580                         break;
 581                 case Opt_nodiscard:
 582                         btrfs_clear_opt(info->mount_opt, DISCARD);
 583                         break;
 584                 case Opt_space_cache:
 585                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 586                         break;
 587                 case Opt_rescan_uuid_tree:
 588                         btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
 589                         break;
 590                 case Opt_no_space_cache:
 591                         btrfs_info(root->fs_info, "disabling disk space caching");
 592                         btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
 593                         break;
 594                 case Opt_inode_cache:
 595                         btrfs_info(root->fs_info, "enabling inode map caching");
 596                         btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
 597                         break;
 598                 case Opt_clear_cache:
 599                         btrfs_info(root->fs_info, "force clearing of disk cache");
 600                         btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
 601                         break;
 602                 case Opt_user_subvol_rm_allowed:
 603                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
 604                         break;
 605                 case Opt_enospc_debug:
 606                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
 607                         break;
 608                 case Opt_noenospc_debug:
 609                         btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
 610                         break;
 611                 case Opt_defrag:
 612                         btrfs_info(root->fs_info, "enabling auto defrag");
 613                         btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
 614                         break;
 615                 case Opt_nodefrag:
 616                         if (btrfs_test_opt(root, AUTO_DEFRAG))
 617                                 btrfs_info(root->fs_info, "disabling auto defrag");
 618                         btrfs_clear_opt(info->mount_opt, AUTO_DEFRAG);
 619                         break;
 620                 case Opt_recovery:
 621                         btrfs_info(root->fs_info, "enabling auto recovery");
 622                         btrfs_set_opt(info->mount_opt, RECOVERY);
 623                         break;
 624                 case Opt_skip_balance:
 625                         btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
 626                         break;
 627 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 628                 case Opt_check_integrity_including_extent_data:
 629                         btrfs_info(root->fs_info,
 630                                    "enabling check integrity including extent data");
 631                         btrfs_set_opt(info->mount_opt,
 632                                       CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
 633                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 634                         break;
 635                 case Opt_check_integrity:
 636                         btrfs_info(root->fs_info, "enabling check integrity");
 637                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 638                         break;
 639                 case Opt_check_integrity_print_mask:
 640                         ret = match_int(&args[0], &intarg);
 641                         if (ret) {
 642                                 goto out;
 643                         } else if (intarg >= 0) {
 644                                 info->check_integrity_print_mask = intarg;
 645                                 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
 646                                        info->check_integrity_print_mask);
 647                         } else {
 648                                 ret = -EINVAL;
 649                                 goto out;
 650                         }
 651                         break;
 652 #else
 653                 case Opt_check_integrity_including_extent_data:
 654                 case Opt_check_integrity:
 655                 case Opt_check_integrity_print_mask:
 656                         btrfs_err(root->fs_info,
 657                                 "support for check_integrity* not compiled in!");
 658                         ret = -EINVAL;
 659                         goto out;
 660 #endif
 661                 case Opt_fatal_errors:
 662                         if (strcmp(args[0].from, "panic") == 0)
 663                                 btrfs_set_opt(info->mount_opt,
 664                                               PANIC_ON_FATAL_ERROR);
 665                         else if (strcmp(args[0].from, "bug") == 0)
 666                                 btrfs_clear_opt(info->mount_opt,
 667                                               PANIC_ON_FATAL_ERROR);
 668                         else {
 669                                 ret = -EINVAL;
 670                                 goto out;
 671                         }
 672                         break;
 673                 case Opt_commit_interval:
 674                         intarg = 0;
 675                         ret = match_int(&args[0], &intarg);
 676                         if (ret < 0) {
 677                                 btrfs_err(root->fs_info, "invalid commit interval");
 678                                 ret = -EINVAL;
 679                                 goto out;
 680                         }
 681                         if (intarg > 0) {
 682                                 if (intarg > 300) {
 683                                         btrfs_warn(root->fs_info, "excessive commit interval %d",
 684                                                         intarg);
 685                                 }
 686                                 info->commit_interval = intarg;
 687                         } else {
 688                                 btrfs_info(root->fs_info, "using default commit interval %ds",
 689                                     BTRFS_DEFAULT_COMMIT_INTERVAL);
 690                                 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
 691                         }
 692                         break;
 693                 case Opt_err:
 694                         btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
 695                         ret = -EINVAL;
 696                         goto out;
 697                 default:
 698                         break;
 699                 }
 700         }
 701 out:
 702         if (!ret && btrfs_test_opt(root, SPACE_CACHE))
 703                 btrfs_info(root->fs_info, "disk space caching is enabled");
 704         kfree(orig);
 705         return ret;
 706 }
 707
 708 /*
 709  * Parse mount options that are required early in the mount process.
 710  *
 711  * All other options will be parsed on much later in the mount process and
 712  * only when we need to allocate a new super block.
 713  */
 714 static int btrfs_parse_early_options(const char *options, fmode_t flags,
 715                 void *holder, char **subvol_name, u64 *subvol_objectid,
 716                 struct btrfs_fs_devices **fs_devices)
 717 {
 718         substring_t args[MAX_OPT_ARGS];
 719         char *device_name, *opts, *orig, *p;
 720         char *num = NULL;
 721         int error = 0;
 722
 723         if (!options)
 724                 return 0;
 725
 726         /*
 727          * strsep changes the string, duplicate it because parse_options
 728          * gets called twice
 729          */
 730         opts = kstrdup(options, GFP_KERNEL);
 731         if (!opts)
 732                 return -ENOMEM;
 733         orig = opts;
 734
 735         while ((p = strsep(&opts, ",")) != NULL) {
 736                 int token;
 737                 if (!*p)
 738                         continue;
 739
 740                 token = match_token(p, tokens, args);
 741                 switch (token) {
 742                 case Opt_subvol:
 743                         kfree(*subvol_name);
 744                         *subvol_name = match_strdup(&args[0]);
 745                         if (!*subvol_name) {
 746                                 error = -ENOMEM;
 747                                 goto out;
 748                         }
 749                         break;
 750                 case Opt_subvolid:
 751                         num = match_strdup(&args[0]);
 752                         if (num) {
 753                                 *subvol_objectid = memparse(num, NULL);
 754                                 kfree(num);
 755                                 /* we want the original fs_tree */
 756                                 if (!*subvol_objectid)
 757                                         *subvol_objectid =
 758                                                 BTRFS_FS_TREE_OBJECTID;
 759                         } else {
 760                                 error = -EINVAL;
 761                                 goto out;
 762                         }
 763                         break;
 764                 case Opt_subvolrootid:
 765                         printk(KERN_WARNING
 766                                 "BTRFS: 'subvolrootid' mount option is deprecated and has "
 767                                 "no effect\n");
 768                         break;
 769                 case Opt_device:
 770                         device_name = match_strdup(&args[0]);
 771                         if (!device_name) {
 772                                 error = -ENOMEM;
 773                                 goto out;
 774                         }
 775                         error = btrfs_scan_one_device(device_name,
 776                                         flags, holder, fs_devices);
 777                         kfree(device_name);
 778                         if (error)
 779                                 goto out;
 780                         break;
 781                 default:
 782                         break;
 783                 }
 784         }
 785
 786 out:
 787         kfree(orig);
 788         return error;
 789 }
 790
 791 static struct dentry *get_default_root(struct super_block *sb,
 792                                        u64 subvol_objectid)
 793 {
 794         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 795         struct btrfs_root *root = fs_info->tree_root;
 796         struct btrfs_root *new_root;
 797         struct btrfs_dir_item *di;
 798         struct btrfs_path *path;
 799         struct btrfs_key location;
 800         struct inode *inode;
 801         u64 dir_id;
 802         int new = 0;
 803
 804         /*
 805          * We have a specific subvol we want to mount, just setup location and
 806          * go look up the root.
 807          */
 808         if (subvol_objectid) {
 809                 location.objectid = subvol_objectid;
 810                 location.type = BTRFS_ROOT_ITEM_KEY;
 811                 location.offset = (u64)-1;
 812                 goto find_root;
 813         }
 814
 815         path = btrfs_alloc_path();
 816         if (!path)
 817                 return ERR_PTR(-ENOMEM);
 818         path->leave_spinning = 1;
 819
 820         /*
 821          * Find the "default" dir item which points to the root item that we
 822          * will mount by default if we haven't been given a specific subvolume
 823          * to mount.
 824          */
 825         dir_id = btrfs_super_root_dir(fs_info->super_copy);
 826         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
 827         if (IS_ERR(di)) {
 828                 btrfs_free_path(path);
 829                 return ERR_CAST(di);
 830         }
 831         if (!di) {
 832                 /*
 833                  * Ok the default dir item isn't there.  This is weird since
 834                  * it's always been there, but don't freak out, just try and
 835                  * mount to root most subvolume.
 836                  */
 837                 btrfs_free_path(path);
 838                 dir_id = BTRFS_FIRST_FREE_OBJECTID;
 839                 new_root = fs_info->fs_root;
 840                 goto setup_root;
 841         }
 842
 843         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 844         btrfs_free_path(path);
 845
 846 find_root:
 847         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
 848         if (IS_ERR(new_root))
 849                 return ERR_CAST(new_root);
 850
 851         dir_id = btrfs_root_dirid(&new_root->root_item);
 852 setup_root:
 853         location.objectid = dir_id;
 854         location.type = BTRFS_INODE_ITEM_KEY;
 855         location.offset = 0;
 856
 857         inode = btrfs_iget(sb, &location, new_root, &new);
 858         if (IS_ERR(inode))
 859                 return ERR_CAST(inode);
 860
 861         /*
 862          * If we're just mounting the root most subvol put the inode and return
 863          * a reference to the dentry.  We will have already gotten a reference
 864          * to the inode in btrfs_fill_super so we're good to go.
 865          */
 866         if (!new && sb->s_root->d_inode == inode) {
 867                 iput(inode);
 868                 return dget(sb->s_root);
 869         }
 870
 871         return d_obtain_alias(inode);
 872 }
 873
 874 static int btrfs_fill_super(struct super_block *sb,
 875                             struct btrfs_fs_devices *fs_devices,
 876                             void *data, int silent)
 877 {
 878         struct inode *inode;
 879         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 880         struct btrfs_key key;
 881         int err;
 882
 883         sb->s_maxbytes = MAX_LFS_FILESIZE;
 884         sb->s_magic = BTRFS_SUPER_MAGIC;
 885         sb->s_op = &btrfs_super_ops;
 886         sb->s_d_op = &btrfs_dentry_operations;
 887         sb->s_export_op = &btrfs_export_ops;
 888         sb->s_xattr = btrfs_xattr_handlers;
 889         sb->s_time_gran = 1;
 890 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 891         sb->s_flags |= MS_POSIXACL;
 892 #endif
 893         sb->s_flags |= MS_I_VERSION;
 894         err = open_ctree(sb, fs_devices, (char *)data);
 895         if (err) {
 896                 printk(KERN_ERR "BTRFS: open_ctree failed\n");
 897                 return err;
 898         }
 899
 900         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 901         key.type = BTRFS_INODE_ITEM_KEY;
 902         key.offset = 0;
 903         inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
 904         if (IS_ERR(inode)) {
 905                 err = PTR_ERR(inode);
 906                 goto fail_close;
 907         }
 908
 909         sb->s_root = d_make_root(inode);
 910         if (!sb->s_root) {
 911                 err = -ENOMEM;
 912                 goto fail_close;
 913         }
 914
 915         save_mount_options(sb, data);
 916         cleancache_init_fs(sb);
 917         sb->s_flags |= MS_ACTIVE;
 918         return 0;
 919
 920 fail_close:
 921         close_ctree(fs_info->tree_root);
 922         return err;
 923 }
 924
 925 int btrfs_sync_fs(struct super_block *sb, int wait)
 926 {
 927         struct btrfs_trans_handle *trans;
 928         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 929         struct btrfs_root *root = fs_info->tree_root;
 930
 931         trace_btrfs_sync_fs(wait);
 932
 933         if (!wait) {
 934                 filemap_flush(fs_info->btree_inode->i_mapping);
 935                 return 0;
 936         }
 937
 938         btrfs_wait_ordered_roots(fs_info, -1);
 939
 940         trans = btrfs_attach_transaction_barrier(root);
 941         if (IS_ERR(trans)) {
 942                 /* no transaction, don't bother */
 943                 if (PTR_ERR(trans) == -ENOENT)
 944                         return 0;
 945                 return PTR_ERR(trans);
 946         }
 947         return btrfs_commit_transaction(trans, root);
 948 }
 949
 950 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 951 {
 952         struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
 953         struct btrfs_root *root = info->tree_root;
 954         char *compress_type;
 955
 956         if (btrfs_test_opt(root, DEGRADED))
 957                 seq_puts(seq, ",degraded");
 958         if (btrfs_test_opt(root, NODATASUM))
 959                 seq_puts(seq, ",nodatasum");
 960         if (btrfs_test_opt(root, NODATACOW))
 961                 seq_puts(seq, ",nodatacow");
 962         if (btrfs_test_opt(root, NOBARRIER))
 963                 seq_puts(seq, ",nobarrier");
 964         if (info->max_inline != 8192 * 1024)
 965                 seq_printf(seq, ",max_inline=%llu", info->max_inline);
 966         if (info->alloc_start != 0)
 967                 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
 968         if (info->thread_pool_size !=  min_t(unsigned long,
 969                                              num_online_cpus() + 2, 8))
 970                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
 971         if (btrfs_test_opt(root, COMPRESS)) {
 972                 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
 973                         compress_type = "zlib";
 974                 else
 975                         compress_type = "lzo";
 976                 if (btrfs_test_opt(root, FORCE_COMPRESS))
 977                         seq_printf(seq, ",compress-force=%s", compress_type);
 978                 else
 979                         seq_printf(seq, ",compress=%s", compress_type);
 980         }
 981         if (btrfs_test_opt(root, NOSSD))
 982                 seq_puts(seq, ",nossd");
 983         if (btrfs_test_opt(root, SSD_SPREAD))
 984                 seq_puts(seq, ",ssd_spread");
 985         else if (btrfs_test_opt(root, SSD))
 986                 seq_puts(seq, ",ssd");
 987         if (btrfs_test_opt(root, NOTREELOG))
 988                 seq_puts(seq, ",notreelog");
 989         if (btrfs_test_opt(root, FLUSHONCOMMIT))
 990                 seq_puts(seq, ",flushoncommit");
 991         if (btrfs_test_opt(root, DISCARD))
 992                 seq_puts(seq, ",discard");
 993         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
 994                 seq_puts(seq, ",noacl");
 995         if (btrfs_test_opt(root, SPACE_CACHE))
 996                 seq_puts(seq, ",space_cache");
 997         else
 998                 seq_puts(seq, ",nospace_cache");
 999         if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1000                 seq_puts(seq, ",rescan_uuid_tree");
1001         if (btrfs_test_opt(root, CLEAR_CACHE))
1002                 seq_puts(seq, ",clear_cache");
1003         if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1004                 seq_puts(seq, ",user_subvol_rm_allowed");
1005         if (btrfs_test_opt(root, ENOSPC_DEBUG))
1006                 seq_puts(seq, ",enospc_debug");
1007         if (btrfs_test_opt(root, AUTO_DEFRAG))
1008                 seq_puts(seq, ",autodefrag");
1009         if (btrfs_test_opt(root, INODE_MAP_CACHE))
1010                 seq_puts(seq, ",inode_cache");
1011         if (btrfs_test_opt(root, SKIP_BALANCE))
1012                 seq_puts(seq, ",skip_balance");
1013         if (btrfs_test_opt(root, RECOVERY))
1014                 seq_puts(seq, ",recovery");
1015 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1016         if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1017                 seq_puts(seq, ",check_int_data");
1018         else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1019                 seq_puts(seq, ",check_int");
1020         if (info->check_integrity_print_mask)
1021                 seq_printf(seq, ",check_int_print_mask=%d",
1022                                 info->check_integrity_print_mask);
1023 #endif
1024         if (info->metadata_ratio)
1025                 seq_printf(seq, ",metadata_ratio=%d",
1026                                 info->metadata_ratio);
1027         if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1028                 seq_puts(seq, ",fatal_errors=panic");
1029         if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1030                 seq_printf(seq, ",commit=%d", info->commit_interval);
1031         return 0;
1032 }
1033
1034 static int btrfs_test_super(struct super_block *s, void *data)
1035 {
1036         struct btrfs_fs_info *p = data;
1037         struct btrfs_fs_info *fs_info = btrfs_sb(s);
1038
1039         return fs_info->fs_devices == p->fs_devices;
1040 }
1041
1042 static int btrfs_set_super(struct super_block *s, void *data)
1043 {
1044         int err = set_anon_super(s, data);
1045         if (!err)
1046                 s->s_fs_info = data;
1047         return err;
1048 }
1049
1050 /*
1051  * subvolumes are identified by ino 256
1052  */
1053 static inline int is_subvolume_inode(struct inode *inode)
1054 {
1055         if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1056                 return 1;
1057         return 0;
1058 }
1059
1060 /*
1061  * This will strip out the subvol=%s argument for an argument string and add
1062  * subvolid=0 to make sure we get the actual tree root for path walking to the
1063  * subvol we want.
1064  */
1065 static char *setup_root_args(char *args)
1066 {
1067         unsigned len = strlen(args) + 2 + 1;
1068         char *src, *dst, *buf;
1069
1070         /*
1071          * We need the same args as before, but with this substitution:
1072          * s!subvol=[^,]+!subvolid=0!
1073          *
1074          * Since the replacement string is up to 2 bytes longer than the
1075          * original, allocate strlen(args) + 2 + 1 bytes.
1076          */
1077
1078         src = strstr(args, "subvol=");
1079         /* This shouldn't happen, but just in case.. */
1080         if (!src)
1081                 return NULL;
1082
1083         buf = dst = kmalloc(len, GFP_NOFS);
1084         if (!buf)
1085                 return NULL;
1086
1087         /*
1088          * If the subvol= arg is not at the start of the string,
1089          * copy whatever precedes it into buf.
1090          */
1091         if (src != args) {
1092                 *src++ = '\0';
1093                 strcpy(buf, args);
1094                 dst += strlen(args);
1095         }
1096
1097         strcpy(dst, "subvolid=0");
1098         dst += strlen("subvolid=0");
1099
1100         /*
1101          * If there is a "," after the original subvol=... string,
1102          * copy that suffix into our buffer.  Otherwise, we're done.
1103          */
1104         src = strchr(src, ',');
1105         if (src)
1106                 strcpy(dst, src);
1107
1108         return buf;
1109 }
1110
1111 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1112                                    const char *device_name, char *data)
1113 {
1114         struct dentry *root;
1115         struct vfsmount *mnt;
1116         char *newargs;
1117
1118         newargs = setup_root_args(data);
1119         if (!newargs)
1120                 return ERR_PTR(-ENOMEM);
1121         mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1122                              newargs);
1123         kfree(newargs);
1124         if (IS_ERR(mnt))
1125                 return ERR_CAST(mnt);
1126
1127         root = mount_subtree(mnt, subvol_name);
1128
1129         if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1130                 struct super_block *s = root->d_sb;
1131                 dput(root);
1132                 root = ERR_PTR(-EINVAL);
1133                 deactivate_locked_super(s);
1134                 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",
1135                                 subvol_name);
1136         }
1137
1138         return root;
1139 }
1140
1141 /*
1142  * Find a superblock for the given device / mount point.
1143  *
1144  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
1145  *        for multiple device setup.  Make sure to keep it in sync.
1146  */
1147 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1148                 const char *device_name, void *data)
1149 {
1150         struct block_device *bdev = NULL;
1151         struct super_block *s;
1152         struct dentry *root;
1153         struct btrfs_fs_devices *fs_devices = NULL;
1154         struct btrfs_fs_info *fs_info = NULL;
1155         fmode_t mode = FMODE_READ;
1156         char *subvol_name = NULL;
1157         u64 subvol_objectid = 0;
1158         int error = 0;
1159
1160         if (!(flags & MS_RDONLY))
1161                 mode |= FMODE_WRITE;
1162
1163         error = btrfs_parse_early_options(data, mode, fs_type,
1164                                           &subvol_name, &subvol_objectid,
1165                                           &fs_devices);
1166         if (error) {
1167                 kfree(subvol_name);
1168                 return ERR_PTR(error);
1169         }
1170
1171         if (subvol_name) {
1172                 root = mount_subvol(subvol_name, flags, device_name, data);
1173                 kfree(subvol_name);
1174                 return root;
1175         }
1176
1177         error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1178         if (error)
1179                 return ERR_PTR(error);
1180
1181         /*
1182          * Setup a dummy root and fs_info for test/set super.  This is because
1183          * we don't actually fill this stuff out until open_ctree, but we need
1184          * it for searching for existing supers, so this lets us do that and
1185          * then open_ctree will properly initialize everything later.
1186          */
1187         fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1188         if (!fs_info)
1189                 return ERR_PTR(-ENOMEM);
1190
1191         fs_info->fs_devices = fs_devices;
1192
1193         fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1194         fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1195         if (!fs_info->super_copy || !fs_info->super_for_commit) {
1196                 error = -ENOMEM;
1197                 goto error_fs_info;
1198         }
1199
1200         error = btrfs_open_devices(fs_devices, mode, fs_type);
1201         if (error)
1202                 goto error_fs_info;
1203
1204         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1205                 error = -EACCES;
1206                 goto error_close_devices;
1207         }
1208
1209         bdev = fs_devices->latest_bdev;
1210         s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1211                  fs_info);
1212         if (IS_ERR(s)) {
1213                 error = PTR_ERR(s);
1214                 goto error_close_devices;
1215         }
1216
1217         if (s->s_root) {
1218                 btrfs_close_devices(fs_devices);
1219                 free_fs_info(fs_info);
1220                 if ((flags ^ s->s_flags) & MS_RDONLY)
1221                         error = -EBUSY;
1222         } else {
1223                 char b[BDEVNAME_SIZE];
1224
1225                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1226                 btrfs_sb(s)->bdev_holder = fs_type;
1227                 error = btrfs_fill_super(s, fs_devices, data,
1228                                          flags & MS_SILENT ? 1 : 0);
1229         }
1230
1231         root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1232         if (IS_ERR(root))
1233                 deactivate_locked_super(s);
1234
1235         return root;
1236
1237 error_close_devices:
1238         btrfs_close_devices(fs_devices);
1239 error_fs_info:
1240         free_fs_info(fs_info);
1241         return ERR_PTR(error);
1242 }
1243
1244 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1245 {
1246         spin_lock_irq(&workers->lock);
1247         workers->max_workers = new_limit;
1248         spin_unlock_irq(&workers->lock);
1249 }
1250
1251 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1252                                      int new_pool_size, int old_pool_size)
1253 {
1254         if (new_pool_size == old_pool_size)
1255                 return;
1256
1257         fs_info->thread_pool_size = new_pool_size;
1258
1259         btrfs_info(fs_info, "resize thread pool %d -> %d",
1260                old_pool_size, new_pool_size);
1261
1262         btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1263         btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1264         btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1265         btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1266         btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1267         btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1268         btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1269         btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1270         btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1271         btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1272         btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1273         btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1274         btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1275         btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1276                               new_pool_size);
1277 }
1278
1279 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1280 {
1281         set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1282 }
1283
1284 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1285                                        unsigned long old_opts, int flags)
1286 {
1287         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1288             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1289              (flags & MS_RDONLY))) {
1290                 /* wait for any defraggers to finish */
1291                 wait_event(fs_info->transaction_wait,
1292                            (atomic_read(&fs_info->defrag_running) == 0));
1293                 if (flags & MS_RDONLY)
1294                         sync_filesystem(fs_info->sb);
1295         }
1296 }
1297
1298 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1299                                          unsigned long old_opts)
1300 {
1301         /*
1302          * We need cleanup all defragable inodes if the autodefragment is
1303          * close or the fs is R/O.
1304          */
1305         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1306             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1307              (fs_info->sb->s_flags & MS_RDONLY))) {
1308                 btrfs_cleanup_defrag_inodes(fs_info);
1309         }
1310
1311         clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1312 }
1313
1314 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1315 {
1316         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1317         struct btrfs_root *root = fs_info->tree_root;
1318         unsigned old_flags = sb->s_flags;
1319         unsigned long old_opts = fs_info->mount_opt;
1320         unsigned long old_compress_type = fs_info->compress_type;
1321         u64 old_max_inline = fs_info->max_inline;
1322         u64 old_alloc_start = fs_info->alloc_start;
1323         int old_thread_pool_size = fs_info->thread_pool_size;
1324         unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1325         int ret;
1326
1327         btrfs_remount_prepare(fs_info);
1328
1329         ret = btrfs_parse_options(root, data);
1330         if (ret) {
1331                 ret = -EINVAL;
1332                 goto restore;
1333         }
1334
1335         btrfs_remount_begin(fs_info, old_opts, *flags);
1336         btrfs_resize_thread_pool(fs_info,
1337                 fs_info->thread_pool_size, old_thread_pool_size);
1338
1339         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1340                 goto out;
1341
1342         if (*flags & MS_RDONLY) {
1343                 /*
1344                  * this also happens on 'umount -rf' or on shutdown, when
1345                  * the filesystem is busy.
1346                  */
1347
1348                 /* wait for the uuid_scan task to finish */
1349                 down(&fs_info->uuid_tree_rescan_sem);
1350                 /* avoid complains from lockdep et al. */
1351                 up(&fs_info->uuid_tree_rescan_sem);
1352
1353                 sb->s_flags |= MS_RDONLY;
1354
1355                 btrfs_dev_replace_suspend_for_unmount(fs_info);
1356                 btrfs_scrub_cancel(fs_info);
1357                 btrfs_pause_balance(fs_info);
1358
1359                 ret = btrfs_commit_super(root);
1360                 if (ret)
1361                         goto restore;
1362         } else {
1363                 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1364                         btrfs_err(fs_info,
1365                                 "Remounting read-write after error is not allowed");
1366                         ret = -EINVAL;
1367                         goto restore;
1368                 }
1369                 if (fs_info->fs_devices->rw_devices == 0) {
1370                         ret = -EACCES;
1371                         goto restore;
1372                 }
1373
1374                 if (fs_info->fs_devices->missing_devices >
1375                      fs_info->num_tolerated_disk_barrier_failures &&
1376                     !(*flags & MS_RDONLY)) {
1377                         btrfs_warn(fs_info,
1378                                 "too many missing devices, writeable remount is not allowed");
1379                         ret = -EACCES;
1380                         goto restore;
1381                 }
1382
1383                 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1384                         ret = -EINVAL;
1385                         goto restore;
1386                 }
1387
1388                 ret = btrfs_cleanup_fs_roots(fs_info);
1389                 if (ret)
1390                         goto restore;
1391
1392                 /* recover relocation */
1393                 ret = btrfs_recover_relocation(root);
1394                 if (ret)
1395                         goto restore;
1396
1397                 ret = btrfs_resume_balance_async(fs_info);
1398                 if (ret)
1399                         goto restore;
1400
1401                 ret = btrfs_resume_dev_replace_async(fs_info);
1402                 if (ret) {
1403                         btrfs_warn(fs_info, "failed to resume dev_replace");
1404                         goto restore;
1405                 }
1406
1407                 if (!fs_info->uuid_root) {
1408                         btrfs_info(fs_info, "creating UUID tree");
1409                         ret = btrfs_create_uuid_tree(fs_info);
1410                         if (ret) {
1411                                 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1412                                 goto restore;
1413                         }
1414                 }
1415                 sb->s_flags &= ~MS_RDONLY;
1416         }
1417 out:
1418         btrfs_remount_cleanup(fs_info, old_opts);
1419         return 0;
1420
1421 restore:
1422         /* We've hit an error - don't reset MS_RDONLY */
1423         if (sb->s_flags & MS_RDONLY)
1424                 old_flags |= MS_RDONLY;
1425         sb->s_flags = old_flags;
1426         fs_info->mount_opt = old_opts;
1427         fs_info->compress_type = old_compress_type;
1428         fs_info->max_inline = old_max_inline;
1429         mutex_lock(&fs_info->chunk_mutex);
1430         fs_info->alloc_start = old_alloc_start;
1431         mutex_unlock(&fs_info->chunk_mutex);
1432         btrfs_resize_thread_pool(fs_info,
1433                 old_thread_pool_size, fs_info->thread_pool_size);
1434         fs_info->metadata_ratio = old_metadata_ratio;
1435         btrfs_remount_cleanup(fs_info, old_opts);
1436         return ret;
1437 }
1438
1439 /* Used to sort the devices by max_avail(descending sort) */
1440 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1441                                        const void *dev_info2)
1442 {
1443         if (((struct btrfs_device_info *)dev_info1)->max_avail >
1444             ((struct btrfs_device_info *)dev_info2)->max_avail)
1445                 return -1;
1446         else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1447                  ((struct btrfs_device_info *)dev_info2)->max_avail)
1448                 return 1;
1449         else
1450         return 0;
1451 }
1452
1453 /*
1454  * sort the devices by max_avail, in which max free extent size of each device
1455  * is stored.(Descending Sort)
1456  */
1457 static inline void btrfs_descending_sort_devices(
1458                                         struct btrfs_device_info *devices,
1459                                         size_t nr_devices)
1460 {
1461         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1462              btrfs_cmp_device_free_bytes, NULL);
1463 }
1464
1465 /*
1466  * The helper to calc the free space on the devices that can be used to store
1467  * file data.
1468  */
1469 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1470 {
1471         struct btrfs_fs_info *fs_info = root->fs_info;
1472         struct btrfs_device_info *devices_info;
1473         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1474         struct btrfs_device *device;
1475         u64 skip_space;
1476         u64 type;
1477         u64 avail_space;
1478         u64 used_space;
1479         u64 min_stripe_size;
1480         int min_stripes = 1, num_stripes = 1;
1481         int i = 0, nr_devices;
1482         int ret;
1483
1484         nr_devices = fs_info->fs_devices->open_devices;
1485         BUG_ON(!nr_devices);
1486
1487         devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1488                                GFP_NOFS);
1489         if (!devices_info)
1490                 return -ENOMEM;
1491
1492         /* calc min stripe number for data space alloction */
1493         type = btrfs_get_alloc_profile(root, 1);
1494         if (type & BTRFS_BLOCK_GROUP_RAID0) {
1495                 min_stripes = 2;
1496                 num_stripes = nr_devices;
1497         } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1498                 min_stripes = 2;
1499                 num_stripes = 2;
1500         } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1501                 min_stripes = 4;
1502                 num_stripes = 4;
1503         }
1504
1505         if (type & BTRFS_BLOCK_GROUP_DUP)
1506                 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1507         else
1508                 min_stripe_size = BTRFS_STRIPE_LEN;
1509
1510         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1511                 if (!device->in_fs_metadata || !device->bdev ||
1512                     device->is_tgtdev_for_dev_replace)
1513                         continue;
1514
1515                 avail_space = device->total_bytes - device->bytes_used;
1516
1517                 /* align with stripe_len */
1518                 do_div(avail_space, BTRFS_STRIPE_LEN);
1519                 avail_space *= BTRFS_STRIPE_LEN;
1520
1521                 /*
1522                  * In order to avoid overwritting the superblock on the drive,
1523                  * btrfs starts at an offset of at least 1MB when doing chunk
1524                  * allocation.
1525                  */
1526                 skip_space = 1024 * 1024;
1527
1528                 /* user can set the offset in fs_info->alloc_start. */
1529                 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1530                     device->total_bytes)
1531                         skip_space = max(fs_info->alloc_start, skip_space);
1532
1533                 /*
1534                  * btrfs can not use the free space in [0, skip_space - 1],
1535                  * we must subtract it from the total. In order to implement
1536                  * it, we account the used space in this range first.
1537                  */
1538                 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1539                                                      &used_space);
1540                 if (ret) {
1541                         kfree(devices_info);
1542                         return ret;
1543                 }
1544
1545                 /* calc the free space in [0, skip_space - 1] */
1546                 skip_space -= used_space;
1547
1548                 /*
1549                  * we can use the free space in [0, skip_space - 1], subtract
1550                  * it from the total.
1551                  */
1552                 if (avail_space && avail_space >= skip_space)
1553                         avail_space -= skip_space;
1554                 else
1555                         avail_space = 0;
1556
1557                 if (avail_space < min_stripe_size)
1558                         continue;
1559
1560                 devices_info[i].dev = device;
1561                 devices_info[i].max_avail = avail_space;
1562
1563                 i++;
1564         }
1565
1566         nr_devices = i;
1567
1568         btrfs_descending_sort_devices(devices_info, nr_devices);
1569
1570         i = nr_devices - 1;
1571         avail_space = 0;
1572         while (nr_devices >= min_stripes) {
1573                 if (num_stripes > nr_devices)
1574                         num_stripes = nr_devices;
1575
1576                 if (devices_info[i].max_avail >= min_stripe_size) {
1577                         int j;
1578                         u64 alloc_size;
1579
1580                         avail_space += devices_info[i].max_avail * num_stripes;
1581                         alloc_size = devices_info[i].max_avail;
1582                         for (j = i + 1 - num_stripes; j <= i; j++)
1583                                 devices_info[j].max_avail -= alloc_size;
1584                 }
1585                 i--;
1586                 nr_devices--;
1587         }
1588
1589         kfree(devices_info);
1590         *free_bytes = avail_space;
1591         return 0;
1592 }
1593
1594 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1595 {
1596         struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1597         struct btrfs_super_block *disk_super = fs_info->super_copy;
1598         struct list_head *head = &fs_info->space_info;
1599         struct btrfs_space_info *found;
1600         u64 total_used = 0;
1601         u64 total_free_data = 0;
1602         int bits = dentry->d_sb->s_blocksize_bits;
1603         __be32 *fsid = (__be32 *)fs_info->fsid;
1604         int ret;
1605
1606         /* holding chunk_muext to avoid allocating new chunks */
1607         mutex_lock(&fs_info->chunk_mutex);
1608         rcu_read_lock();
1609         list_for_each_entry_rcu(found, head, list) {
1610                 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1611                         total_free_data += found->disk_total - found->disk_used;
1612                         total_free_data -=
1613                                 btrfs_account_ro_block_groups_free_space(found);
1614                 }
1615
1616                 total_used += found->disk_used;
1617         }
1618         rcu_read_unlock();
1619
1620         buf->f_namelen = BTRFS_NAME_LEN;
1621         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1622         buf->f_bfree = buf->f_blocks - (total_used >> bits);
1623         buf->f_bsize = dentry->d_sb->s_blocksize;
1624         buf->f_type = BTRFS_SUPER_MAGIC;
1625         buf->f_bavail = total_free_data;
1626         ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1627         if (ret) {
1628                 mutex_unlock(&fs_info->chunk_mutex);
1629                 return ret;
1630         }
1631         buf->f_bavail += total_free_data;
1632         buf->f_bavail = buf->f_bavail >> bits;
1633         mutex_unlock(&fs_info->chunk_mutex);
1634
1635         /* We treat it as constant endianness (it doesn't matter _which_)
1636            because we want the fsid to come out the same whether mounted
1637            on a big-endian or little-endian host */
1638         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1639         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1640         /* Mask in the root object ID too, to disambiguate subvols */
1641         buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1642         buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1643
1644         return 0;
1645 }
1646
1647 static void btrfs_kill_super(struct super_block *sb)
1648 {
1649         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1650         kill_anon_super(sb);
1651         free_fs_info(fs_info);
1652 }
1653
1654 static struct file_system_type btrfs_fs_type = {
1655         .owner          = THIS_MODULE,
1656         .name           = "btrfs",
1657         .mount          = btrfs_mount,
1658         .kill_sb        = btrfs_kill_super,
1659         .fs_flags       = FS_REQUIRES_DEV,
1660 };
1661 MODULE_ALIAS_FS("btrfs");
1662
1663 /*
1664  * used by btrfsctl to scan devices when no FS is mounted
1665  */
1666 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1667                                 unsigned long arg)
1668 {
1669         struct btrfs_ioctl_vol_args *vol;
1670         struct btrfs_fs_devices *fs_devices;
1671         int ret = -ENOTTY;
1672
1673         if (!capable(CAP_SYS_ADMIN))
1674                 return -EPERM;
1675
1676         vol = memdup_user((void __user *)arg, sizeof(*vol));
1677         if (IS_ERR(vol))
1678                 return PTR_ERR(vol);
1679
1680         switch (cmd) {
1681         case BTRFS_IOC_SCAN_DEV:
1682                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1683                                             &btrfs_fs_type, &fs_devices);
1684                 break;
1685         case BTRFS_IOC_DEVICES_READY:
1686                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1687                                             &btrfs_fs_type, &fs_devices);
1688                 if (ret)
1689                         break;
1690                 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1691                 break;
1692         }
1693
1694         kfree(vol);
1695         return ret;
1696 }
1697
1698 static int btrfs_freeze(struct super_block *sb)
1699 {
1700         struct btrfs_trans_handle *trans;
1701         struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1702
1703         trans = btrfs_attach_transaction_barrier(root);
1704         if (IS_ERR(trans)) {
1705                 /* no transaction, don't bother */
1706                 if (PTR_ERR(trans) == -ENOENT)
1707                         return 0;
1708                 return PTR_ERR(trans);
1709         }
1710         return btrfs_commit_transaction(trans, root);
1711 }
1712
1713 static int btrfs_unfreeze(struct super_block *sb)
1714 {
1715         return 0;
1716 }
1717
1718 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1719 {
1720         struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1721         struct btrfs_fs_devices *cur_devices;
1722         struct btrfs_device *dev, *first_dev = NULL;
1723         struct list_head *head;
1724         struct rcu_string *name;
1725
1726         mutex_lock(&fs_info->fs_devices->device_list_mutex);
1727         cur_devices = fs_info->fs_devices;
1728         while (cur_devices) {
1729                 head = &cur_devices->devices;
1730                 list_for_each_entry(dev, head, dev_list) {
1731                         if (dev->missing)
1732                                 continue;
1733                         if (!first_dev || dev->devid < first_dev->devid)
1734                                 first_dev = dev;
1735                 }
1736                 cur_devices = cur_devices->seed;
1737         }
1738
1739         if (first_dev) {
1740                 rcu_read_lock();
1741                 name = rcu_dereference(first_dev->name);
1742                 seq_escape(m, name->str, " \t\n\\");
1743                 rcu_read_unlock();
1744         } else {
1745                 WARN_ON(1);
1746         }
1747         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1748         return 0;
1749 }
1750
1751 static const struct super_operations btrfs_super_ops = {
1752         .drop_inode     = btrfs_drop_inode,
1753         .evict_inode    = btrfs_evict_inode,
1754         .put_super      = btrfs_put_super,
1755         .sync_fs        = btrfs_sync_fs,
1756         .show_options   = btrfs_show_options,
1757         .show_devname   = btrfs_show_devname,
1758         .write_inode    = btrfs_write_inode,
1759         .alloc_inode    = btrfs_alloc_inode,
1760         .destroy_inode  = btrfs_destroy_inode,
1761         .statfs         = btrfs_statfs,
1762         .remount_fs     = btrfs_remount,
1763         .freeze_fs      = btrfs_freeze,
1764         .unfreeze_fs    = btrfs_unfreeze,
1765 };
1766
1767 static const struct file_operations btrfs_ctl_fops = {
1768         .unlocked_ioctl  = btrfs_control_ioctl,
1769         .compat_ioctl = btrfs_control_ioctl,
1770         .owner   = THIS_MODULE,
1771         .llseek = noop_llseek,
1772 };
1773
1774 static struct miscdevice btrfs_misc = {
1775         .minor          = BTRFS_MINOR,
1776         .name           = "btrfs-control",
1777         .fops           = &btrfs_ctl_fops
1778 };
1779
1780 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1781 MODULE_ALIAS("devname:btrfs-control");
1782
1783 static int btrfs_interface_init(void)
1784 {
1785         return misc_register(&btrfs_misc);
1786 }
1787
1788 static void btrfs_interface_exit(void)
1789 {
1790         if (misc_deregister(&btrfs_misc) < 0)
1791                 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
1792 }
1793
1794 static void btrfs_print_info(void)
1795 {
1796         printk(KERN_INFO "Btrfs loaded"
1797 #ifdef CONFIG_BTRFS_DEBUG
1798                         ", debug=on"
1799 #endif
1800 #ifdef CONFIG_BTRFS_ASSERT
1801                         ", assert=on"
1802 #endif
1803 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1804                         ", integrity-checker=on"
1805 #endif
1806                         "\n");
1807 }
1808
1809 static int btrfs_run_sanity_tests(void)
1810 {
1811         int ret;
1812
1813         ret = btrfs_init_test_fs();
1814         if (ret)
1815                 return ret;
1816
1817         ret = btrfs_test_free_space_cache();
1818         if (ret)
1819                 goto out;
1820         ret = btrfs_test_extent_buffer_operations();
1821         if (ret)
1822                 goto out;
1823         ret = btrfs_test_extent_io();
1824         if (ret)
1825                 goto out;
1826         ret = btrfs_test_inodes();
1827 out:
1828         btrfs_destroy_test_fs();
1829         return ret;
1830 }
1831
1832 static int __init init_btrfs_fs(void)
1833 {
1834         int err;
1835
1836         err = btrfs_init_sysfs();
1837         if (err)
1838                 return err;
1839
1840         btrfs_init_compress();
1841
1842         err = btrfs_init_cachep();
1843         if (err)
1844                 goto free_compress;
1845
1846         err = extent_io_init();
1847         if (err)
1848                 goto free_cachep;
1849
1850         err = extent_map_init();
1851         if (err)
1852                 goto free_extent_io;
1853
1854         err = ordered_data_init();
1855         if (err)
1856                 goto free_extent_map;
1857
1858         err = btrfs_delayed_inode_init();
1859         if (err)
1860                 goto free_ordered_data;
1861
1862         err = btrfs_auto_defrag_init();
1863         if (err)
1864                 goto free_delayed_inode;
1865
1866         err = btrfs_delayed_ref_init();
1867         if (err)
1868                 goto free_auto_defrag;
1869
1870         err = btrfs_prelim_ref_init();
1871         if (err)
1872                 goto free_prelim_ref;
1873
1874         err = btrfs_interface_init();
1875         if (err)
1876                 goto free_delayed_ref;
1877
1878         btrfs_init_lockdep();
1879
1880         btrfs_print_info();
1881
1882         err = btrfs_run_sanity_tests();
1883         if (err)
1884                 goto unregister_ioctl;
1885
1886         err = register_filesystem(&btrfs_fs_type);
1887         if (err)
1888                 goto unregister_ioctl;
1889
1890         return 0;
1891
1892 unregister_ioctl:
1893         btrfs_interface_exit();
1894 free_prelim_ref:
1895         btrfs_prelim_ref_exit();
1896 free_delayed_ref:
1897         btrfs_delayed_ref_exit();
1898 free_auto_defrag:
1899         btrfs_auto_defrag_exit();
1900 free_delayed_inode:
1901         btrfs_delayed_inode_exit();
1902 free_ordered_data:
1903         ordered_data_exit();
1904 free_extent_map:
1905         extent_map_exit();
1906 free_extent_io:
1907         extent_io_exit();
1908 free_cachep:
1909         btrfs_destroy_cachep();
1910 free_compress:
1911         btrfs_exit_compress();
1912         btrfs_exit_sysfs();
1913         return err;
1914 }
1915
1916 static void __exit exit_btrfs_fs(void)
1917 {
1918         btrfs_destroy_cachep();
1919         btrfs_delayed_ref_exit();
1920         btrfs_auto_defrag_exit();
1921         btrfs_delayed_inode_exit();
1922         btrfs_prelim_ref_exit();
1923         ordered_data_exit();
1924         extent_map_exit();
1925         extent_io_exit();
1926         btrfs_interface_exit();
1927         unregister_filesystem(&btrfs_fs_type);
1928         btrfs_exit_sysfs();
1929         btrfs_cleanup_fs_uuids();
1930         btrfs_exit_compress();
1931 }
1932
1933 module_init(init_btrfs_fs)
1934 module_exit(exit_btrfs_fs)
1935
1936 MODULE_LICENSE("GPL");