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, Opt_noflushoncommit, Opt_acl, Opt_datacow,
 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_datacow, "datacow"},
 339         {Opt_nobarrier, "nobarrier"},
 340         {Opt_barrier, "barrier"},
 341         {Opt_max_inline, "max_inline=%s"},
 342         {Opt_alloc_start, "alloc_start=%s"},
 343         {Opt_thread_pool, "thread_pool=%d"},
 344         {Opt_compress, "compress"},
 345         {Opt_compress_type, "compress=%s"},
 346         {Opt_compress_force, "compress-force"},
 347         {Opt_compress_force_type, "compress-force=%s"},
 348         {Opt_ssd, "ssd"},
 349         {Opt_ssd_spread, "ssd_spread"},
 350         {Opt_nossd, "nossd"},
 351         {Opt_acl, "acl"},
 352         {Opt_noacl, "noacl"},
 353         {Opt_notreelog, "notreelog"},
 354         {Opt_flushoncommit, "flushoncommit"},
 355         {Opt_noflushoncommit, "noflushoncommit"},
 356         {Opt_ratio, "metadata_ratio=%d"},
 357         {Opt_discard, "discard"},
 358         {Opt_nodiscard, "nodiscard"},
 359         {Opt_space_cache, "space_cache"},
 360         {Opt_clear_cache, "clear_cache"},
 361         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
 362         {Opt_enospc_debug, "enospc_debug"},
 363         {Opt_noenospc_debug, "noenospc_debug"},
 364         {Opt_subvolrootid, "subvolrootid=%d"},
 365         {Opt_defrag, "autodefrag"},
 366         {Opt_nodefrag, "noautodefrag"},
 367         {Opt_inode_cache, "inode_cache"},
 368         {Opt_no_space_cache, "nospace_cache"},
 369         {Opt_recovery, "recovery"},
 370         {Opt_skip_balance, "skip_balance"},
 371         {Opt_check_integrity, "check_int"},
 372         {Opt_check_integrity_including_extent_data, "check_int_data"},
 373         {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
 374         {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
 375         {Opt_fatal_errors, "fatal_errors=%s"},
 376         {Opt_commit_interval, "commit=%d"},
 377         {Opt_err, NULL},
 378 };
 379
 380 /*
 381  * Regular mount options parser.  Everything that is needed only when
 382  * reading in a new superblock is parsed here.
 383  * XXX JDM: This needs to be cleaned up for remount.
 384  */
 385 int btrfs_parse_options(struct btrfs_root *root, char *options)
 386 {
 387         struct btrfs_fs_info *info = root->fs_info;
 388         substring_t args[MAX_OPT_ARGS];
 389         char *p, *num, *orig = NULL;
 390         u64 cache_gen;
 391         int intarg;
 392         int ret = 0;
 393         char *compress_type;
 394         bool compress_force = false;
 395
 396         cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
 397         if (cache_gen)
 398                 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 399
 400         if (!options)
 401                 goto out;
 402
 403         /*
 404          * strsep changes the string, duplicate it because parse_options
 405          * gets called twice
 406          */
 407         options = kstrdup(options, GFP_NOFS);
 408         if (!options)
 409                 return -ENOMEM;
 410
 411         orig = options;
 412
 413         while ((p = strsep(&options, ",")) != NULL) {
 414                 int token;
 415                 if (!*p)
 416                         continue;
 417
 418                 token = match_token(p, tokens, args);
 419                 switch (token) {
 420                 case Opt_degraded:
 421                         btrfs_info(root->fs_info, "allowing degraded mounts");
 422                         btrfs_set_opt(info->mount_opt, DEGRADED);
 423                         break;
 424                 case Opt_subvol:
 425                 case Opt_subvolid:
 426                 case Opt_subvolrootid:
 427                 case Opt_device:
 428                         /*
 429                          * These are parsed by btrfs_parse_early_options
 430                          * and can be happily ignored here.
 431                          */
 432                         break;
 433                 case Opt_nodatasum:
 434                         btrfs_info(root->fs_info, "setting nodatasum");
 435                         btrfs_set_opt(info->mount_opt, NODATASUM);
 436                         break;
 437                 case Opt_nodatacow:
 438                         if (!btrfs_test_opt(root, COMPRESS) ||
 439                                 !btrfs_test_opt(root, FORCE_COMPRESS)) {
 440                                         btrfs_info(root->fs_info,
 441                                                 "setting nodatacow, compression disabled");
 442                         } else {
 443                                 btrfs_info(root->fs_info, "setting nodatacow");
 444                         }
 445                         btrfs_clear_opt(info->mount_opt, COMPRESS);
 446                         btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 447                         btrfs_set_opt(info->mount_opt, NODATACOW);
 448                         btrfs_set_opt(info->mount_opt, NODATASUM);
 449                         break;
 450                 case Opt_datacow:
 451                         if (btrfs_test_opt(root, NODATACOW))
 452                                 btrfs_info(root->fs_info, "setting datacow");
 453                         btrfs_clear_opt(info->mount_opt, NODATACOW);
 454                         break;
 455                 case Opt_compress_force:
 456                 case Opt_compress_force_type:
 457                         compress_force = true;
 458                         /* Fallthrough */
 459                 case Opt_compress:
 460                 case Opt_compress_type:
 461                         if (token == Opt_compress ||
 462                             token == Opt_compress_force ||
 463                             strcmp(args[0].from, "zlib") == 0) {
 464                                 compress_type = "zlib";
 465                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
 466                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 467                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 468                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 469                         } else if (strcmp(args[0].from, "lzo") == 0) {
 470                                 compress_type = "lzo";
 471                                 info->compress_type = BTRFS_COMPRESS_LZO;
 472                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 473                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 474                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 475                                 btrfs_set_fs_incompat(info, COMPRESS_LZO);
 476                         } else if (strncmp(args[0].from, "no", 2) == 0) {
 477                                 compress_type = "no";
 478                                 btrfs_clear_opt(info->mount_opt, COMPRESS);
 479                                 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 480                                 compress_force = false;
 481                         } else {
 482                                 ret = -EINVAL;
 483                                 goto out;
 484                         }
 485
 486                         if (compress_force) {
 487                                 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
 488                                 btrfs_info(root->fs_info, "force %s compression",
 489                                         compress_type);
 490                         } else if (btrfs_test_opt(root, COMPRESS)) {
 491                                 pr_info("btrfs: use %s compression\n",
 492                                         compress_type);
 493                         }
 494                         break;
 495                 case Opt_ssd:
 496                         btrfs_info(root->fs_info, "use ssd allocation scheme");
 497                         btrfs_set_opt(info->mount_opt, SSD);
 498                         break;
 499                 case Opt_ssd_spread:
 500                         btrfs_info(root->fs_info, "use spread ssd allocation scheme");
 501                         btrfs_set_opt(info->mount_opt, SSD);
 502                         btrfs_set_opt(info->mount_opt, SSD_SPREAD);
 503                         break;
 504                 case Opt_nossd:
 505                         btrfs_info(root->fs_info, "not using ssd allocation scheme");
 506                         btrfs_set_opt(info->mount_opt, NOSSD);
 507                         btrfs_clear_opt(info->mount_opt, SSD);
 508                         btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
 509                         break;
 510                 case Opt_barrier:
 511                         if (btrfs_test_opt(root, NOBARRIER))
 512                                 btrfs_info(root->fs_info, "turning on barriers");
 513                         btrfs_clear_opt(info->mount_opt, NOBARRIER);
 514                         break;
 515                 case Opt_nobarrier:
 516                         btrfs_info(root->fs_info, "turning off barriers");
 517                         btrfs_set_opt(info->mount_opt, NOBARRIER);
 518                         break;
 519                 case Opt_thread_pool:
 520                         ret = match_int(&args[0], &intarg);
 521                         if (ret) {
 522                                 goto out;
 523                         } else if (intarg > 0) {
 524                                 info->thread_pool_size = intarg;
 525                         } else {
 526                                 ret = -EINVAL;
 527                                 goto out;
 528                         }
 529                         break;
 530                 case Opt_max_inline:
 531                         num = match_strdup(&args[0]);
 532                         if (num) {
 533                                 info->max_inline = memparse(num, NULL);
 534                                 kfree(num);
 535
 536                                 if (info->max_inline) {
 537                                         info->max_inline = max_t(u64,
 538                                                 info->max_inline,
 539                                                 root->sectorsize);
 540                                 }
 541                                 btrfs_info(root->fs_info, "max_inline at %llu",
 542                                         info->max_inline);
 543                         } else {
 544                                 ret = -ENOMEM;
 545                                 goto out;
 546                         }
 547                         break;
 548                 case Opt_alloc_start:
 549                         num = match_strdup(&args[0]);
 550                         if (num) {
 551                                 mutex_lock(&info->chunk_mutex);
 552                                 info->alloc_start = memparse(num, NULL);
 553                                 mutex_unlock(&info->chunk_mutex);
 554                                 kfree(num);
 555                                 btrfs_info(root->fs_info, "allocations start at %llu",
 556                                         info->alloc_start);
 557                         } else {
 558                                 ret = -ENOMEM;
 559                                 goto out;
 560                         }
 561                         break;
 562                 case Opt_acl:
 563                         root->fs_info->sb->s_flags |= MS_POSIXACL;
 564                         break;
 565                 case Opt_noacl:
 566                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
 567                         break;
 568                 case Opt_notreelog:
 569                         btrfs_info(root->fs_info, "disabling tree log");
 570                         btrfs_set_opt(info->mount_opt, NOTREELOG);
 571                         break;
 572                 case Opt_flushoncommit:
 573                         btrfs_info(root->fs_info, "turning on flush-on-commit");
 574                         btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
 575                         break;
 576                 case Opt_noflushoncommit:
 577                         if (btrfs_test_opt(root, FLUSHONCOMMIT))
 578                                 btrfs_info(root->fs_info, "turning off flush-on-commit");
 579                         btrfs_clear_opt(info->mount_opt, FLUSHONCOMMIT);
 580                         break;
 581                 case Opt_ratio:
 582                         ret = match_int(&args[0], &intarg);
 583                         if (ret) {
 584                                 goto out;
 585                         } else if (intarg >= 0) {
 586                                 info->metadata_ratio = intarg;
 587                                 btrfs_info(root->fs_info, "metadata ratio %d",
 588                                        info->metadata_ratio);
 589                         } else {
 590                                 ret = -EINVAL;
 591                                 goto out;
 592                         }
 593                         break;
 594                 case Opt_discard:
 595                         btrfs_set_opt(info->mount_opt, DISCARD);
 596                         break;
 597                 case Opt_nodiscard:
 598                         btrfs_clear_opt(info->mount_opt, DISCARD);
 599                         break;
 600                 case Opt_space_cache:
 601                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 602                         break;
 603                 case Opt_rescan_uuid_tree:
 604                         btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
 605                         break;
 606                 case Opt_no_space_cache:
 607                         btrfs_info(root->fs_info, "disabling disk space caching");
 608                         btrfs_clear_opt(info->mount_opt, SPACE_CACHE);
 609                         break;
 610                 case Opt_inode_cache:
 611                         btrfs_info(root->fs_info, "enabling inode map caching");
 612                         btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
 613                         break;
 614                 case Opt_clear_cache:
 615                         btrfs_info(root->fs_info, "force clearing of disk cache");
 616                         btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
 617                         break;
 618                 case Opt_user_subvol_rm_allowed:
 619                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
 620                         break;
 621                 case Opt_enospc_debug:
 622                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
 623                         break;
 624                 case Opt_noenospc_debug:
 625                         btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
 626                         break;
 627                 case Opt_defrag:
 628                         btrfs_info(root->fs_info, "enabling auto defrag");
 629                         btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
 630                         break;
 631                 case Opt_nodefrag:
 632                         if (btrfs_test_opt(root, AUTO_DEFRAG))
 633                                 btrfs_info(root->fs_info, "disabling auto defrag");
 634                         btrfs_clear_opt(info->mount_opt, AUTO_DEFRAG);
 635                         break;
 636                 case Opt_recovery:
 637                         btrfs_info(root->fs_info, "enabling auto recovery");
 638                         btrfs_set_opt(info->mount_opt, RECOVERY);
 639                         break;
 640                 case Opt_skip_balance:
 641                         btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
 642                         break;
 643 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 644                 case Opt_check_integrity_including_extent_data:
 645                         btrfs_info(root->fs_info,
 646                                    "enabling check integrity including extent data");
 647                         btrfs_set_opt(info->mount_opt,
 648                                       CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
 649                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 650                         break;
 651                 case Opt_check_integrity:
 652                         btrfs_info(root->fs_info, "enabling check integrity");
 653                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 654                         break;
 655                 case Opt_check_integrity_print_mask:
 656                         ret = match_int(&args[0], &intarg);
 657                         if (ret) {
 658                                 goto out;
 659                         } else if (intarg >= 0) {
 660                                 info->check_integrity_print_mask = intarg;
 661                                 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
 662                                        info->check_integrity_print_mask);
 663                         } else {
 664                                 ret = -EINVAL;
 665                                 goto out;
 666                         }
 667                         break;
 668 #else
 669                 case Opt_check_integrity_including_extent_data:
 670                 case Opt_check_integrity:
 671                 case Opt_check_integrity_print_mask:
 672                         btrfs_err(root->fs_info,
 673                                 "support for check_integrity* not compiled in!");
 674                         ret = -EINVAL;
 675                         goto out;
 676 #endif
 677                 case Opt_fatal_errors:
 678                         if (strcmp(args[0].from, "panic") == 0)
 679                                 btrfs_set_opt(info->mount_opt,
 680                                               PANIC_ON_FATAL_ERROR);
 681                         else if (strcmp(args[0].from, "bug") == 0)
 682                                 btrfs_clear_opt(info->mount_opt,
 683                                               PANIC_ON_FATAL_ERROR);
 684                         else {
 685                                 ret = -EINVAL;
 686                                 goto out;
 687                         }
 688                         break;
 689                 case Opt_commit_interval:
 690                         intarg = 0;
 691                         ret = match_int(&args[0], &intarg);
 692                         if (ret < 0) {
 693                                 btrfs_err(root->fs_info, "invalid commit interval");
 694                                 ret = -EINVAL;
 695                                 goto out;
 696                         }
 697                         if (intarg > 0) {
 698                                 if (intarg > 300) {
 699                                         btrfs_warn(root->fs_info, "excessive commit interval %d",
 700                                                         intarg);
 701                                 }
 702                                 info->commit_interval = intarg;
 703                         } else {
 704                                 btrfs_info(root->fs_info, "using default commit interval %ds",
 705                                     BTRFS_DEFAULT_COMMIT_INTERVAL);
 706                                 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
 707                         }
 708                         break;
 709                 case Opt_err:
 710                         btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
 711                         ret = -EINVAL;
 712                         goto out;
 713                 default:
 714                         break;
 715                 }
 716         }
 717 out:
 718         if (!ret && btrfs_test_opt(root, SPACE_CACHE))
 719                 btrfs_info(root->fs_info, "disk space caching is enabled");
 720         kfree(orig);
 721         return ret;
 722 }
 723
 724 /*
 725  * Parse mount options that are required early in the mount process.
 726  *
 727  * All other options will be parsed on much later in the mount process and
 728  * only when we need to allocate a new super block.
 729  */
 730 static int btrfs_parse_early_options(const char *options, fmode_t flags,
 731                 void *holder, char **subvol_name, u64 *subvol_objectid,
 732                 struct btrfs_fs_devices **fs_devices)
 733 {
 734         substring_t args[MAX_OPT_ARGS];
 735         char *device_name, *opts, *orig, *p;
 736         char *num = NULL;
 737         int error = 0;
 738
 739         if (!options)
 740                 return 0;
 741
 742         /*
 743          * strsep changes the string, duplicate it because parse_options
 744          * gets called twice
 745          */
 746         opts = kstrdup(options, GFP_KERNEL);
 747         if (!opts)
 748                 return -ENOMEM;
 749         orig = opts;
 750
 751         while ((p = strsep(&opts, ",")) != NULL) {
 752                 int token;
 753                 if (!*p)
 754                         continue;
 755
 756                 token = match_token(p, tokens, args);
 757                 switch (token) {
 758                 case Opt_subvol:
 759                         kfree(*subvol_name);
 760                         *subvol_name = match_strdup(&args[0]);
 761                         if (!*subvol_name) {
 762                                 error = -ENOMEM;
 763                                 goto out;
 764                         }
 765                         break;
 766                 case Opt_subvolid:
 767                         num = match_strdup(&args[0]);
 768                         if (num) {
 769                                 *subvol_objectid = memparse(num, NULL);
 770                                 kfree(num);
 771                                 /* we want the original fs_tree */
 772                                 if (!*subvol_objectid)
 773                                         *subvol_objectid =
 774                                                 BTRFS_FS_TREE_OBJECTID;
 775                         } else {
 776                                 error = -EINVAL;
 777                                 goto out;
 778                         }
 779                         break;
 780                 case Opt_subvolrootid:
 781                         printk(KERN_WARNING
 782                                 "BTRFS: 'subvolrootid' mount option is deprecated and has "
 783                                 "no effect\n");
 784                         break;
 785                 case Opt_device:
 786                         device_name = match_strdup(&args[0]);
 787                         if (!device_name) {
 788                                 error = -ENOMEM;
 789                                 goto out;
 790                         }
 791                         error = btrfs_scan_one_device(device_name,
 792                                         flags, holder, fs_devices);
 793                         kfree(device_name);
 794                         if (error)
 795                                 goto out;
 796                         break;
 797                 default:
 798                         break;
 799                 }
 800         }
 801
 802 out:
 803         kfree(orig);
 804         return error;
 805 }
 806
 807 static struct dentry *get_default_root(struct super_block *sb,
 808                                        u64 subvol_objectid)
 809 {
 810         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 811         struct btrfs_root *root = fs_info->tree_root;
 812         struct btrfs_root *new_root;
 813         struct btrfs_dir_item *di;
 814         struct btrfs_path *path;
 815         struct btrfs_key location;
 816         struct inode *inode;
 817         u64 dir_id;
 818         int new = 0;
 819
 820         /*
 821          * We have a specific subvol we want to mount, just setup location and
 822          * go look up the root.
 823          */
 824         if (subvol_objectid) {
 825                 location.objectid = subvol_objectid;
 826                 location.type = BTRFS_ROOT_ITEM_KEY;
 827                 location.offset = (u64)-1;
 828                 goto find_root;
 829         }
 830
 831         path = btrfs_alloc_path();
 832         if (!path)
 833                 return ERR_PTR(-ENOMEM);
 834         path->leave_spinning = 1;
 835
 836         /*
 837          * Find the "default" dir item which points to the root item that we
 838          * will mount by default if we haven't been given a specific subvolume
 839          * to mount.
 840          */
 841         dir_id = btrfs_super_root_dir(fs_info->super_copy);
 842         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
 843         if (IS_ERR(di)) {
 844                 btrfs_free_path(path);
 845                 return ERR_CAST(di);
 846         }
 847         if (!di) {
 848                 /*
 849                  * Ok the default dir item isn't there.  This is weird since
 850                  * it's always been there, but don't freak out, just try and
 851                  * mount to root most subvolume.
 852                  */
 853                 btrfs_free_path(path);
 854                 dir_id = BTRFS_FIRST_FREE_OBJECTID;
 855                 new_root = fs_info->fs_root;
 856                 goto setup_root;
 857         }
 858
 859         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 860         btrfs_free_path(path);
 861
 862 find_root:
 863         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
 864         if (IS_ERR(new_root))
 865                 return ERR_CAST(new_root);
 866
 867         dir_id = btrfs_root_dirid(&new_root->root_item);
 868 setup_root:
 869         location.objectid = dir_id;
 870         location.type = BTRFS_INODE_ITEM_KEY;
 871         location.offset = 0;
 872
 873         inode = btrfs_iget(sb, &location, new_root, &new);
 874         if (IS_ERR(inode))
 875                 return ERR_CAST(inode);
 876
 877         /*
 878          * If we're just mounting the root most subvol put the inode and return
 879          * a reference to the dentry.  We will have already gotten a reference
 880          * to the inode in btrfs_fill_super so we're good to go.
 881          */
 882         if (!new && sb->s_root->d_inode == inode) {
 883                 iput(inode);
 884                 return dget(sb->s_root);
 885         }
 886
 887         return d_obtain_alias(inode);
 888 }
 889
 890 static int btrfs_fill_super(struct super_block *sb,
 891                             struct btrfs_fs_devices *fs_devices,
 892                             void *data, int silent)
 893 {
 894         struct inode *inode;
 895         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 896         struct btrfs_key key;
 897         int err;
 898
 899         sb->s_maxbytes = MAX_LFS_FILESIZE;
 900         sb->s_magic = BTRFS_SUPER_MAGIC;
 901         sb->s_op = &btrfs_super_ops;
 902         sb->s_d_op = &btrfs_dentry_operations;
 903         sb->s_export_op = &btrfs_export_ops;
 904         sb->s_xattr = btrfs_xattr_handlers;
 905         sb->s_time_gran = 1;
 906 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 907         sb->s_flags |= MS_POSIXACL;
 908 #endif
 909         sb->s_flags |= MS_I_VERSION;
 910         err = open_ctree(sb, fs_devices, (char *)data);
 911         if (err) {
 912                 printk(KERN_ERR "BTRFS: open_ctree failed\n");
 913                 return err;
 914         }
 915
 916         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 917         key.type = BTRFS_INODE_ITEM_KEY;
 918         key.offset = 0;
 919         inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
 920         if (IS_ERR(inode)) {
 921                 err = PTR_ERR(inode);
 922                 goto fail_close;
 923         }
 924
 925         sb->s_root = d_make_root(inode);
 926         if (!sb->s_root) {
 927                 err = -ENOMEM;
 928                 goto fail_close;
 929         }
 930
 931         save_mount_options(sb, data);
 932         cleancache_init_fs(sb);
 933         sb->s_flags |= MS_ACTIVE;
 934         return 0;
 935
 936 fail_close:
 937         close_ctree(fs_info->tree_root);
 938         return err;
 939 }
 940
 941 int btrfs_sync_fs(struct super_block *sb, int wait)
 942 {
 943         struct btrfs_trans_handle *trans;
 944         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 945         struct btrfs_root *root = fs_info->tree_root;
 946
 947         trace_btrfs_sync_fs(wait);
 948
 949         if (!wait) {
 950                 filemap_flush(fs_info->btree_inode->i_mapping);
 951                 return 0;
 952         }
 953
 954         btrfs_wait_ordered_roots(fs_info, -1);
 955
 956         trans = btrfs_attach_transaction_barrier(root);
 957         if (IS_ERR(trans)) {
 958                 /* no transaction, don't bother */
 959                 if (PTR_ERR(trans) == -ENOENT)
 960                         return 0;
 961                 return PTR_ERR(trans);
 962         }
 963         return btrfs_commit_transaction(trans, root);
 964 }
 965
 966 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
 967 {
 968         struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
 969         struct btrfs_root *root = info->tree_root;
 970         char *compress_type;
 971
 972         if (btrfs_test_opt(root, DEGRADED))
 973                 seq_puts(seq, ",degraded");
 974         if (btrfs_test_opt(root, NODATASUM))
 975                 seq_puts(seq, ",nodatasum");
 976         if (btrfs_test_opt(root, NODATACOW))
 977                 seq_puts(seq, ",nodatacow");
 978         if (btrfs_test_opt(root, NOBARRIER))
 979                 seq_puts(seq, ",nobarrier");
 980         if (info->max_inline != 8192 * 1024)
 981                 seq_printf(seq, ",max_inline=%llu", info->max_inline);
 982         if (info->alloc_start != 0)
 983                 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
 984         if (info->thread_pool_size !=  min_t(unsigned long,
 985                                              num_online_cpus() + 2, 8))
 986                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
 987         if (btrfs_test_opt(root, COMPRESS)) {
 988                 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
 989                         compress_type = "zlib";
 990                 else
 991                         compress_type = "lzo";
 992                 if (btrfs_test_opt(root, FORCE_COMPRESS))
 993                         seq_printf(seq, ",compress-force=%s", compress_type);
 994                 else
 995                         seq_printf(seq, ",compress=%s", compress_type);
 996         }
 997         if (btrfs_test_opt(root, NOSSD))
 998                 seq_puts(seq, ",nossd");
 999         if (btrfs_test_opt(root, SSD_SPREAD))
1000                 seq_puts(seq, ",ssd_spread");
1001         else if (btrfs_test_opt(root, SSD))
1002                 seq_puts(seq, ",ssd");
1003         if (btrfs_test_opt(root, NOTREELOG))
1004                 seq_puts(seq, ",notreelog");
1005         if (btrfs_test_opt(root, FLUSHONCOMMIT))
1006                 seq_puts(seq, ",flushoncommit");
1007         if (btrfs_test_opt(root, DISCARD))
1008                 seq_puts(seq, ",discard");
1009         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
1010                 seq_puts(seq, ",noacl");
1011         if (btrfs_test_opt(root, SPACE_CACHE))
1012                 seq_puts(seq, ",space_cache");
1013         else
1014                 seq_puts(seq, ",nospace_cache");
1015         if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1016                 seq_puts(seq, ",rescan_uuid_tree");
1017         if (btrfs_test_opt(root, CLEAR_CACHE))
1018                 seq_puts(seq, ",clear_cache");
1019         if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1020                 seq_puts(seq, ",user_subvol_rm_allowed");
1021         if (btrfs_test_opt(root, ENOSPC_DEBUG))
1022                 seq_puts(seq, ",enospc_debug");
1023         if (btrfs_test_opt(root, AUTO_DEFRAG))
1024                 seq_puts(seq, ",autodefrag");
1025         if (btrfs_test_opt(root, INODE_MAP_CACHE))
1026                 seq_puts(seq, ",inode_cache");
1027         if (btrfs_test_opt(root, SKIP_BALANCE))
1028                 seq_puts(seq, ",skip_balance");
1029         if (btrfs_test_opt(root, RECOVERY))
1030                 seq_puts(seq, ",recovery");
1031 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1032         if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1033                 seq_puts(seq, ",check_int_data");
1034         else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1035                 seq_puts(seq, ",check_int");
1036         if (info->check_integrity_print_mask)
1037                 seq_printf(seq, ",check_int_print_mask=%d",
1038                                 info->check_integrity_print_mask);
1039 #endif
1040         if (info->metadata_ratio)
1041                 seq_printf(seq, ",metadata_ratio=%d",
1042                                 info->metadata_ratio);
1043         if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1044                 seq_puts(seq, ",fatal_errors=panic");
1045         if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1046                 seq_printf(seq, ",commit=%d", info->commit_interval);
1047         return 0;
1048 }
1049
1050 static int btrfs_test_super(struct super_block *s, void *data)
1051 {
1052         struct btrfs_fs_info *p = data;
1053         struct btrfs_fs_info *fs_info = btrfs_sb(s);
1054
1055         return fs_info->fs_devices == p->fs_devices;
1056 }
1057
1058 static int btrfs_set_super(struct super_block *s, void *data)
1059 {
1060         int err = set_anon_super(s, data);
1061         if (!err)
1062                 s->s_fs_info = data;
1063         return err;
1064 }
1065
1066 /*
1067  * subvolumes are identified by ino 256
1068  */
1069 static inline int is_subvolume_inode(struct inode *inode)
1070 {
1071         if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1072                 return 1;
1073         return 0;
1074 }
1075
1076 /*
1077  * This will strip out the subvol=%s argument for an argument string and add
1078  * subvolid=0 to make sure we get the actual tree root for path walking to the
1079  * subvol we want.
1080  */
1081 static char *setup_root_args(char *args)
1082 {
1083         unsigned len = strlen(args) + 2 + 1;
1084         char *src, *dst, *buf;
1085
1086         /*
1087          * We need the same args as before, but with this substitution:
1088          * s!subvol=[^,]+!subvolid=0!
1089          *
1090          * Since the replacement string is up to 2 bytes longer than the
1091          * original, allocate strlen(args) + 2 + 1 bytes.
1092          */
1093
1094         src = strstr(args, "subvol=");
1095         /* This shouldn't happen, but just in case.. */
1096         if (!src)
1097                 return NULL;
1098
1099         buf = dst = kmalloc(len, GFP_NOFS);
1100         if (!buf)
1101                 return NULL;
1102
1103         /*
1104          * If the subvol= arg is not at the start of the string,
1105          * copy whatever precedes it into buf.
1106          */
1107         if (src != args) {
1108                 *src++ = '\0';
1109                 strcpy(buf, args);
1110                 dst += strlen(args);
1111         }
1112
1113         strcpy(dst, "subvolid=0");
1114         dst += strlen("subvolid=0");
1115
1116         /*
1117          * If there is a "," after the original subvol=... string,
1118          * copy that suffix into our buffer.  Otherwise, we're done.
1119          */
1120         src = strchr(src, ',');
1121         if (src)
1122                 strcpy(dst, src);
1123
1124         return buf;
1125 }
1126
1127 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1128                                    const char *device_name, char *data)
1129 {
1130         struct dentry *root;
1131         struct vfsmount *mnt;
1132         char *newargs;
1133
1134         newargs = setup_root_args(data);
1135         if (!newargs)
1136                 return ERR_PTR(-ENOMEM);
1137         mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1138                              newargs);
1139         kfree(newargs);
1140         if (IS_ERR(mnt))
1141                 return ERR_CAST(mnt);
1142
1143         root = mount_subtree(mnt, subvol_name);
1144
1145         if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1146                 struct super_block *s = root->d_sb;
1147                 dput(root);
1148                 root = ERR_PTR(-EINVAL);
1149                 deactivate_locked_super(s);
1150                 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",
1151                                 subvol_name);
1152         }
1153
1154         return root;
1155 }
1156
1157 /*
1158  * Find a superblock for the given device / mount point.
1159  *
1160  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
1161  *        for multiple device setup.  Make sure to keep it in sync.
1162  */
1163 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1164                 const char *device_name, void *data)
1165 {
1166         struct block_device *bdev = NULL;
1167         struct super_block *s;
1168         struct dentry *root;
1169         struct btrfs_fs_devices *fs_devices = NULL;
1170         struct btrfs_fs_info *fs_info = NULL;
1171         fmode_t mode = FMODE_READ;
1172         char *subvol_name = NULL;
1173         u64 subvol_objectid = 0;
1174         int error = 0;
1175
1176         if (!(flags & MS_RDONLY))
1177                 mode |= FMODE_WRITE;
1178
1179         error = btrfs_parse_early_options(data, mode, fs_type,
1180                                           &subvol_name, &subvol_objectid,
1181                                           &fs_devices);
1182         if (error) {
1183                 kfree(subvol_name);
1184                 return ERR_PTR(error);
1185         }
1186
1187         if (subvol_name) {
1188                 root = mount_subvol(subvol_name, flags, device_name, data);
1189                 kfree(subvol_name);
1190                 return root;
1191         }
1192
1193         error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1194         if (error)
1195                 return ERR_PTR(error);
1196
1197         /*
1198          * Setup a dummy root and fs_info for test/set super.  This is because
1199          * we don't actually fill this stuff out until open_ctree, but we need
1200          * it for searching for existing supers, so this lets us do that and
1201          * then open_ctree will properly initialize everything later.
1202          */
1203         fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1204         if (!fs_info)
1205                 return ERR_PTR(-ENOMEM);
1206
1207         fs_info->fs_devices = fs_devices;
1208
1209         fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1210         fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1211         if (!fs_info->super_copy || !fs_info->super_for_commit) {
1212                 error = -ENOMEM;
1213                 goto error_fs_info;
1214         }
1215
1216         error = btrfs_open_devices(fs_devices, mode, fs_type);
1217         if (error)
1218                 goto error_fs_info;
1219
1220         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1221                 error = -EACCES;
1222                 goto error_close_devices;
1223         }
1224
1225         bdev = fs_devices->latest_bdev;
1226         s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1227                  fs_info);
1228         if (IS_ERR(s)) {
1229                 error = PTR_ERR(s);
1230                 goto error_close_devices;
1231         }
1232
1233         if (s->s_root) {
1234                 btrfs_close_devices(fs_devices);
1235                 free_fs_info(fs_info);
1236                 if ((flags ^ s->s_flags) & MS_RDONLY)
1237                         error = -EBUSY;
1238         } else {
1239                 char b[BDEVNAME_SIZE];
1240
1241                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1242                 btrfs_sb(s)->bdev_holder = fs_type;
1243                 error = btrfs_fill_super(s, fs_devices, data,
1244                                          flags & MS_SILENT ? 1 : 0);
1245         }
1246
1247         root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1248         if (IS_ERR(root))
1249                 deactivate_locked_super(s);
1250
1251         return root;
1252
1253 error_close_devices:
1254         btrfs_close_devices(fs_devices);
1255 error_fs_info:
1256         free_fs_info(fs_info);
1257         return ERR_PTR(error);
1258 }
1259
1260 static void btrfs_set_max_workers(struct btrfs_workers *workers, int new_limit)
1261 {
1262         spin_lock_irq(&workers->lock);
1263         workers->max_workers = new_limit;
1264         spin_unlock_irq(&workers->lock);
1265 }
1266
1267 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1268                                      int new_pool_size, int old_pool_size)
1269 {
1270         if (new_pool_size == old_pool_size)
1271                 return;
1272
1273         fs_info->thread_pool_size = new_pool_size;
1274
1275         btrfs_info(fs_info, "resize thread pool %d -> %d",
1276                old_pool_size, new_pool_size);
1277
1278         btrfs_set_max_workers(&fs_info->generic_worker, new_pool_size);
1279         btrfs_set_max_workers(&fs_info->workers, new_pool_size);
1280         btrfs_set_max_workers(&fs_info->delalloc_workers, new_pool_size);
1281         btrfs_set_max_workers(&fs_info->submit_workers, new_pool_size);
1282         btrfs_set_max_workers(&fs_info->caching_workers, new_pool_size);
1283         btrfs_set_max_workers(&fs_info->fixup_workers, new_pool_size);
1284         btrfs_set_max_workers(&fs_info->endio_workers, new_pool_size);
1285         btrfs_set_max_workers(&fs_info->endio_meta_workers, new_pool_size);
1286         btrfs_set_max_workers(&fs_info->endio_meta_write_workers, new_pool_size);
1287         btrfs_set_max_workers(&fs_info->endio_write_workers, new_pool_size);
1288         btrfs_set_max_workers(&fs_info->endio_freespace_worker, new_pool_size);
1289         btrfs_set_max_workers(&fs_info->delayed_workers, new_pool_size);
1290         btrfs_set_max_workers(&fs_info->readahead_workers, new_pool_size);
1291         btrfs_set_max_workers(&fs_info->scrub_wr_completion_workers,
1292                               new_pool_size);
1293 }
1294
1295 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1296 {
1297         set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1298 }
1299
1300 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1301                                        unsigned long old_opts, int flags)
1302 {
1303         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1304             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1305              (flags & MS_RDONLY))) {
1306                 /* wait for any defraggers to finish */
1307                 wait_event(fs_info->transaction_wait,
1308                            (atomic_read(&fs_info->defrag_running) == 0));
1309                 if (flags & MS_RDONLY)
1310                         sync_filesystem(fs_info->sb);
1311         }
1312 }
1313
1314 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1315                                          unsigned long old_opts)
1316 {
1317         /*
1318          * We need cleanup all defragable inodes if the autodefragment is
1319          * close or the fs is R/O.
1320          */
1321         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1322             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1323              (fs_info->sb->s_flags & MS_RDONLY))) {
1324                 btrfs_cleanup_defrag_inodes(fs_info);
1325         }
1326
1327         clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1328 }
1329
1330 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1331 {
1332         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1333         struct btrfs_root *root = fs_info->tree_root;
1334         unsigned old_flags = sb->s_flags;
1335         unsigned long old_opts = fs_info->mount_opt;
1336         unsigned long old_compress_type = fs_info->compress_type;
1337         u64 old_max_inline = fs_info->max_inline;
1338         u64 old_alloc_start = fs_info->alloc_start;
1339         int old_thread_pool_size = fs_info->thread_pool_size;
1340         unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1341         int ret;
1342
1343         btrfs_remount_prepare(fs_info);
1344
1345         ret = btrfs_parse_options(root, data);
1346         if (ret) {
1347                 ret = -EINVAL;
1348                 goto restore;
1349         }
1350
1351         btrfs_remount_begin(fs_info, old_opts, *flags);
1352         btrfs_resize_thread_pool(fs_info,
1353                 fs_info->thread_pool_size, old_thread_pool_size);
1354
1355         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1356                 goto out;
1357
1358         if (*flags & MS_RDONLY) {
1359                 /*
1360                  * this also happens on 'umount -rf' or on shutdown, when
1361                  * the filesystem is busy.
1362                  */
1363
1364                 /* wait for the uuid_scan task to finish */
1365                 down(&fs_info->uuid_tree_rescan_sem);
1366                 /* avoid complains from lockdep et al. */
1367                 up(&fs_info->uuid_tree_rescan_sem);
1368
1369                 sb->s_flags |= MS_RDONLY;
1370
1371                 btrfs_dev_replace_suspend_for_unmount(fs_info);
1372                 btrfs_scrub_cancel(fs_info);
1373                 btrfs_pause_balance(fs_info);
1374
1375                 ret = btrfs_commit_super(root);
1376                 if (ret)
1377                         goto restore;
1378         } else {
1379                 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1380                         btrfs_err(fs_info,
1381                                 "Remounting read-write after error is not allowed");
1382                         ret = -EINVAL;
1383                         goto restore;
1384                 }
1385                 if (fs_info->fs_devices->rw_devices == 0) {
1386                         ret = -EACCES;
1387                         goto restore;
1388                 }
1389
1390                 if (fs_info->fs_devices->missing_devices >
1391                      fs_info->num_tolerated_disk_barrier_failures &&
1392                     !(*flags & MS_RDONLY)) {
1393                         btrfs_warn(fs_info,
1394                                 "too many missing devices, writeable remount is not allowed");
1395                         ret = -EACCES;
1396                         goto restore;
1397                 }
1398
1399                 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1400                         ret = -EINVAL;
1401                         goto restore;
1402                 }
1403
1404                 ret = btrfs_cleanup_fs_roots(fs_info);
1405                 if (ret)
1406                         goto restore;
1407
1408                 /* recover relocation */
1409                 ret = btrfs_recover_relocation(root);
1410                 if (ret)
1411                         goto restore;
1412
1413                 ret = btrfs_resume_balance_async(fs_info);
1414                 if (ret)
1415                         goto restore;
1416
1417                 ret = btrfs_resume_dev_replace_async(fs_info);
1418                 if (ret) {
1419                         btrfs_warn(fs_info, "failed to resume dev_replace");
1420                         goto restore;
1421                 }
1422
1423                 if (!fs_info->uuid_root) {
1424                         btrfs_info(fs_info, "creating UUID tree");
1425                         ret = btrfs_create_uuid_tree(fs_info);
1426                         if (ret) {
1427                                 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1428                                 goto restore;
1429                         }
1430                 }
1431                 sb->s_flags &= ~MS_RDONLY;
1432         }
1433 out:
1434         btrfs_remount_cleanup(fs_info, old_opts);
1435         return 0;
1436
1437 restore:
1438         /* We've hit an error - don't reset MS_RDONLY */
1439         if (sb->s_flags & MS_RDONLY)
1440                 old_flags |= MS_RDONLY;
1441         sb->s_flags = old_flags;
1442         fs_info->mount_opt = old_opts;
1443         fs_info->compress_type = old_compress_type;
1444         fs_info->max_inline = old_max_inline;
1445         mutex_lock(&fs_info->chunk_mutex);
1446         fs_info->alloc_start = old_alloc_start;
1447         mutex_unlock(&fs_info->chunk_mutex);
1448         btrfs_resize_thread_pool(fs_info,
1449                 old_thread_pool_size, fs_info->thread_pool_size);
1450         fs_info->metadata_ratio = old_metadata_ratio;
1451         btrfs_remount_cleanup(fs_info, old_opts);
1452         return ret;
1453 }
1454
1455 /* Used to sort the devices by max_avail(descending sort) */
1456 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1457                                        const void *dev_info2)
1458 {
1459         if (((struct btrfs_device_info *)dev_info1)->max_avail >
1460             ((struct btrfs_device_info *)dev_info2)->max_avail)
1461                 return -1;
1462         else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1463                  ((struct btrfs_device_info *)dev_info2)->max_avail)
1464                 return 1;
1465         else
1466         return 0;
1467 }
1468
1469 /*
1470  * sort the devices by max_avail, in which max free extent size of each device
1471  * is stored.(Descending Sort)
1472  */
1473 static inline void btrfs_descending_sort_devices(
1474                                         struct btrfs_device_info *devices,
1475                                         size_t nr_devices)
1476 {
1477         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1478              btrfs_cmp_device_free_bytes, NULL);
1479 }
1480
1481 /*
1482  * The helper to calc the free space on the devices that can be used to store
1483  * file data.
1484  */
1485 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1486 {
1487         struct btrfs_fs_info *fs_info = root->fs_info;
1488         struct btrfs_device_info *devices_info;
1489         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1490         struct btrfs_device *device;
1491         u64 skip_space;
1492         u64 type;
1493         u64 avail_space;
1494         u64 used_space;
1495         u64 min_stripe_size;
1496         int min_stripes = 1, num_stripes = 1;
1497         int i = 0, nr_devices;
1498         int ret;
1499
1500         nr_devices = fs_info->fs_devices->open_devices;
1501         BUG_ON(!nr_devices);
1502
1503         devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1504                                GFP_NOFS);
1505         if (!devices_info)
1506                 return -ENOMEM;
1507
1508         /* calc min stripe number for data space alloction */
1509         type = btrfs_get_alloc_profile(root, 1);
1510         if (type & BTRFS_BLOCK_GROUP_RAID0) {
1511                 min_stripes = 2;
1512                 num_stripes = nr_devices;
1513         } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1514                 min_stripes = 2;
1515                 num_stripes = 2;
1516         } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1517                 min_stripes = 4;
1518                 num_stripes = 4;
1519         }
1520
1521         if (type & BTRFS_BLOCK_GROUP_DUP)
1522                 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1523         else
1524                 min_stripe_size = BTRFS_STRIPE_LEN;
1525
1526         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1527                 if (!device->in_fs_metadata || !device->bdev ||
1528                     device->is_tgtdev_for_dev_replace)
1529                         continue;
1530
1531                 avail_space = device->total_bytes - device->bytes_used;
1532
1533                 /* align with stripe_len */
1534                 do_div(avail_space, BTRFS_STRIPE_LEN);
1535                 avail_space *= BTRFS_STRIPE_LEN;
1536
1537                 /*
1538                  * In order to avoid overwritting the superblock on the drive,
1539                  * btrfs starts at an offset of at least 1MB when doing chunk
1540                  * allocation.
1541                  */
1542                 skip_space = 1024 * 1024;
1543
1544                 /* user can set the offset in fs_info->alloc_start. */
1545                 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1546                     device->total_bytes)
1547                         skip_space = max(fs_info->alloc_start, skip_space);
1548
1549                 /*
1550                  * btrfs can not use the free space in [0, skip_space - 1],
1551                  * we must subtract it from the total. In order to implement
1552                  * it, we account the used space in this range first.
1553                  */
1554                 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1555                                                      &used_space);
1556                 if (ret) {
1557                         kfree(devices_info);
1558                         return ret;
1559                 }
1560
1561                 /* calc the free space in [0, skip_space - 1] */
1562                 skip_space -= used_space;
1563
1564                 /*
1565                  * we can use the free space in [0, skip_space - 1], subtract
1566                  * it from the total.
1567                  */
1568                 if (avail_space && avail_space >= skip_space)
1569                         avail_space -= skip_space;
1570                 else
1571                         avail_space = 0;
1572
1573                 if (avail_space < min_stripe_size)
1574                         continue;
1575
1576                 devices_info[i].dev = device;
1577                 devices_info[i].max_avail = avail_space;
1578
1579                 i++;
1580         }
1581
1582         nr_devices = i;
1583
1584         btrfs_descending_sort_devices(devices_info, nr_devices);
1585
1586         i = nr_devices - 1;
1587         avail_space = 0;
1588         while (nr_devices >= min_stripes) {
1589                 if (num_stripes > nr_devices)
1590                         num_stripes = nr_devices;
1591
1592                 if (devices_info[i].max_avail >= min_stripe_size) {
1593                         int j;
1594                         u64 alloc_size;
1595
1596                         avail_space += devices_info[i].max_avail * num_stripes;
1597                         alloc_size = devices_info[i].max_avail;
1598                         for (j = i + 1 - num_stripes; j <= i; j++)
1599                                 devices_info[j].max_avail -= alloc_size;
1600                 }
1601                 i--;
1602                 nr_devices--;
1603         }
1604
1605         kfree(devices_info);
1606         *free_bytes = avail_space;
1607         return 0;
1608 }
1609
1610 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1611 {
1612         struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1613         struct btrfs_super_block *disk_super = fs_info->super_copy;
1614         struct list_head *head = &fs_info->space_info;
1615         struct btrfs_space_info *found;
1616         u64 total_used = 0;
1617         u64 total_free_data = 0;
1618         int bits = dentry->d_sb->s_blocksize_bits;
1619         __be32 *fsid = (__be32 *)fs_info->fsid;
1620         int ret;
1621
1622         /* holding chunk_muext to avoid allocating new chunks */
1623         mutex_lock(&fs_info->chunk_mutex);
1624         rcu_read_lock();
1625         list_for_each_entry_rcu(found, head, list) {
1626                 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1627                         total_free_data += found->disk_total - found->disk_used;
1628                         total_free_data -=
1629                                 btrfs_account_ro_block_groups_free_space(found);
1630                 }
1631
1632                 total_used += found->disk_used;
1633         }
1634         rcu_read_unlock();
1635
1636         buf->f_namelen = BTRFS_NAME_LEN;
1637         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1638         buf->f_bfree = buf->f_blocks - (total_used >> bits);
1639         buf->f_bsize = dentry->d_sb->s_blocksize;
1640         buf->f_type = BTRFS_SUPER_MAGIC;
1641         buf->f_bavail = total_free_data;
1642         ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1643         if (ret) {
1644                 mutex_unlock(&fs_info->chunk_mutex);
1645                 return ret;
1646         }
1647         buf->f_bavail += total_free_data;
1648         buf->f_bavail = buf->f_bavail >> bits;
1649         mutex_unlock(&fs_info->chunk_mutex);
1650
1651         /* We treat it as constant endianness (it doesn't matter _which_)
1652            because we want the fsid to come out the same whether mounted
1653            on a big-endian or little-endian host */
1654         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1655         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1656         /* Mask in the root object ID too, to disambiguate subvols */
1657         buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1658         buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1659
1660         return 0;
1661 }
1662
1663 static void btrfs_kill_super(struct super_block *sb)
1664 {
1665         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1666         kill_anon_super(sb);
1667         free_fs_info(fs_info);
1668 }
1669
1670 static struct file_system_type btrfs_fs_type = {
1671         .owner          = THIS_MODULE,
1672         .name           = "btrfs",
1673         .mount          = btrfs_mount,
1674         .kill_sb        = btrfs_kill_super,
1675         .fs_flags       = FS_REQUIRES_DEV,
1676 };
1677 MODULE_ALIAS_FS("btrfs");
1678
1679 /*
1680  * used by btrfsctl to scan devices when no FS is mounted
1681  */
1682 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1683                                 unsigned long arg)
1684 {
1685         struct btrfs_ioctl_vol_args *vol;
1686         struct btrfs_fs_devices *fs_devices;
1687         int ret = -ENOTTY;
1688
1689         if (!capable(CAP_SYS_ADMIN))
1690                 return -EPERM;
1691
1692         vol = memdup_user((void __user *)arg, sizeof(*vol));
1693         if (IS_ERR(vol))
1694                 return PTR_ERR(vol);
1695
1696         switch (cmd) {
1697         case BTRFS_IOC_SCAN_DEV:
1698                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1699                                             &btrfs_fs_type, &fs_devices);
1700                 break;
1701         case BTRFS_IOC_DEVICES_READY:
1702                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1703                                             &btrfs_fs_type, &fs_devices);
1704                 if (ret)
1705                         break;
1706                 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1707                 break;
1708         }
1709
1710         kfree(vol);
1711         return ret;
1712 }
1713
1714 static int btrfs_freeze(struct super_block *sb)
1715 {
1716         struct btrfs_trans_handle *trans;
1717         struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1718
1719         trans = btrfs_attach_transaction_barrier(root);
1720         if (IS_ERR(trans)) {
1721                 /* no transaction, don't bother */
1722                 if (PTR_ERR(trans) == -ENOENT)
1723                         return 0;
1724                 return PTR_ERR(trans);
1725         }
1726         return btrfs_commit_transaction(trans, root);
1727 }
1728
1729 static int btrfs_unfreeze(struct super_block *sb)
1730 {
1731         return 0;
1732 }
1733
1734 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1735 {
1736         struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1737         struct btrfs_fs_devices *cur_devices;
1738         struct btrfs_device *dev, *first_dev = NULL;
1739         struct list_head *head;
1740         struct rcu_string *name;
1741
1742         mutex_lock(&fs_info->fs_devices->device_list_mutex);
1743         cur_devices = fs_info->fs_devices;
1744         while (cur_devices) {
1745                 head = &cur_devices->devices;
1746                 list_for_each_entry(dev, head, dev_list) {
1747                         if (dev->missing)
1748                                 continue;
1749                         if (!first_dev || dev->devid < first_dev->devid)
1750                                 first_dev = dev;
1751                 }
1752                 cur_devices = cur_devices->seed;
1753         }
1754
1755         if (first_dev) {
1756                 rcu_read_lock();
1757                 name = rcu_dereference(first_dev->name);
1758                 seq_escape(m, name->str, " \t\n\\");
1759                 rcu_read_unlock();
1760         } else {
1761                 WARN_ON(1);
1762         }
1763         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1764         return 0;
1765 }
1766
1767 static const struct super_operations btrfs_super_ops = {
1768         .drop_inode     = btrfs_drop_inode,
1769         .evict_inode    = btrfs_evict_inode,
1770         .put_super      = btrfs_put_super,
1771         .sync_fs        = btrfs_sync_fs,
1772         .show_options   = btrfs_show_options,
1773         .show_devname   = btrfs_show_devname,
1774         .write_inode    = btrfs_write_inode,
1775         .alloc_inode    = btrfs_alloc_inode,
1776         .destroy_inode  = btrfs_destroy_inode,
1777         .statfs         = btrfs_statfs,
1778         .remount_fs     = btrfs_remount,
1779         .freeze_fs      = btrfs_freeze,
1780         .unfreeze_fs    = btrfs_unfreeze,
1781 };
1782
1783 static const struct file_operations btrfs_ctl_fops = {
1784         .unlocked_ioctl  = btrfs_control_ioctl,
1785         .compat_ioctl = btrfs_control_ioctl,
1786         .owner   = THIS_MODULE,
1787         .llseek = noop_llseek,
1788 };
1789
1790 static struct miscdevice btrfs_misc = {
1791         .minor          = BTRFS_MINOR,
1792         .name           = "btrfs-control",
1793         .fops           = &btrfs_ctl_fops
1794 };
1795
1796 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1797 MODULE_ALIAS("devname:btrfs-control");
1798
1799 static int btrfs_interface_init(void)
1800 {
1801         return misc_register(&btrfs_misc);
1802 }
1803
1804 static void btrfs_interface_exit(void)
1805 {
1806         if (misc_deregister(&btrfs_misc) < 0)
1807                 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
1808 }
1809
1810 static void btrfs_print_info(void)
1811 {
1812         printk(KERN_INFO "Btrfs loaded"
1813 #ifdef CONFIG_BTRFS_DEBUG
1814                         ", debug=on"
1815 #endif
1816 #ifdef CONFIG_BTRFS_ASSERT
1817                         ", assert=on"
1818 #endif
1819 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1820                         ", integrity-checker=on"
1821 #endif
1822                         "\n");
1823 }
1824
1825 static int btrfs_run_sanity_tests(void)
1826 {
1827         int ret;
1828
1829         ret = btrfs_init_test_fs();
1830         if (ret)
1831                 return ret;
1832
1833         ret = btrfs_test_free_space_cache();
1834         if (ret)
1835                 goto out;
1836         ret = btrfs_test_extent_buffer_operations();
1837         if (ret)
1838                 goto out;
1839         ret = btrfs_test_extent_io();
1840         if (ret)
1841                 goto out;
1842         ret = btrfs_test_inodes();
1843 out:
1844         btrfs_destroy_test_fs();
1845         return ret;
1846 }
1847
1848 static int __init init_btrfs_fs(void)
1849 {
1850         int err;
1851
1852         err = btrfs_init_sysfs();
1853         if (err)
1854                 return err;
1855
1856         btrfs_init_compress();
1857
1858         err = btrfs_init_cachep();
1859         if (err)
1860                 goto free_compress;
1861
1862         err = extent_io_init();
1863         if (err)
1864                 goto free_cachep;
1865
1866         err = extent_map_init();
1867         if (err)
1868                 goto free_extent_io;
1869
1870         err = ordered_data_init();
1871         if (err)
1872                 goto free_extent_map;
1873
1874         err = btrfs_delayed_inode_init();
1875         if (err)
1876                 goto free_ordered_data;
1877
1878         err = btrfs_auto_defrag_init();
1879         if (err)
1880                 goto free_delayed_inode;
1881
1882         err = btrfs_delayed_ref_init();
1883         if (err)
1884                 goto free_auto_defrag;
1885
1886         err = btrfs_prelim_ref_init();
1887         if (err)
1888                 goto free_prelim_ref;
1889
1890         err = btrfs_interface_init();
1891         if (err)
1892                 goto free_delayed_ref;
1893
1894         btrfs_init_lockdep();
1895
1896         btrfs_print_info();
1897
1898         err = btrfs_run_sanity_tests();
1899         if (err)
1900                 goto unregister_ioctl;
1901
1902         err = register_filesystem(&btrfs_fs_type);
1903         if (err)
1904                 goto unregister_ioctl;
1905
1906         return 0;
1907
1908 unregister_ioctl:
1909         btrfs_interface_exit();
1910 free_prelim_ref:
1911         btrfs_prelim_ref_exit();
1912 free_delayed_ref:
1913         btrfs_delayed_ref_exit();
1914 free_auto_defrag:
1915         btrfs_auto_defrag_exit();
1916 free_delayed_inode:
1917         btrfs_delayed_inode_exit();
1918 free_ordered_data:
1919         ordered_data_exit();
1920 free_extent_map:
1921         extent_map_exit();
1922 free_extent_io:
1923         extent_io_exit();
1924 free_cachep:
1925         btrfs_destroy_cachep();
1926 free_compress:
1927         btrfs_exit_compress();
1928         btrfs_exit_sysfs();
1929         return err;
1930 }
1931
1932 static void __exit exit_btrfs_fs(void)
1933 {
1934         btrfs_destroy_cachep();
1935         btrfs_delayed_ref_exit();
1936         btrfs_auto_defrag_exit();
1937         btrfs_delayed_inode_exit();
1938         btrfs_prelim_ref_exit();
1939         ordered_data_exit();
1940         extent_map_exit();
1941         extent_io_exit();
1942         btrfs_interface_exit();
1943         unregister_filesystem(&btrfs_fs_type);
1944         btrfs_exit_sysfs();
1945         btrfs_cleanup_fs_uuids();
1946         btrfs_exit_compress();
1947 }
1948
1949 module_init(init_btrfs_fs)
1950 module_exit(exit_btrfs_fs)
1951
1952 MODULE_LICENSE("GPL");