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 "hash.h"
  52 #include "props.h"
  53 #include "xattr.h"
  54 #include "volumes.h"
  55 #include "export.h"
  56 #include "compression.h"
  57 #include "rcu-string.h"
  58 #include "dev-replace.h"
  59 #include "free-space-cache.h"
  60 #include "backref.h"
  61 #include "tests/btrfs-tests.h"
  62
  63 #define CREATE_TRACE_POINTS
  64 #include <trace/events/btrfs.h>
  65
  66 static const struct super_operations btrfs_super_ops;
  67 static struct file_system_type btrfs_fs_type;
  68
  69 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
  70
  71 static const char *btrfs_decode_error(int errno)
  72 {
  73         char *errstr = "unknown";
  74
  75         switch (errno) {
  76         case -EIO:
  77                 errstr = "IO failure";
  78                 break;
  79         case -ENOMEM:
  80                 errstr = "Out of memory";
  81                 break;
  82         case -EROFS:
  83                 errstr = "Readonly filesystem";
  84                 break;
  85         case -EEXIST:
  86                 errstr = "Object already exists";
  87                 break;
  88         case -ENOSPC:
  89                 errstr = "No space left";
  90                 break;
  91         case -ENOENT:
  92                 errstr = "No such entry";
  93                 break;
  94         }
  95
  96         return errstr;
  97 }
  98
  99 static void save_error_info(struct btrfs_fs_info *fs_info)
 100 {
 101         /*
 102          * today we only save the error info into ram.  Long term we'll
 103          * also send it down to the disk
 104          */
 105         set_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state);
 106 }
 107
 108 /* btrfs handle error by forcing the filesystem readonly */
 109 static void btrfs_handle_error(struct btrfs_fs_info *fs_info)
 110 {
 111         struct super_block *sb = fs_info->sb;
 112
 113         if (sb->s_flags & MS_RDONLY)
 114                 return;
 115
 116         if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
 117                 sb->s_flags |= MS_RDONLY;
 118                 btrfs_info(fs_info, "forced readonly");
 119                 /*
 120                  * Note that a running device replace operation is not
 121                  * canceled here although there is no way to update
 122                  * the progress. It would add the risk of a deadlock,
 123                  * therefore the canceling is ommited. The only penalty
 124                  * is that some I/O remains active until the procedure
 125                  * completes. The next time when the filesystem is
 126                  * mounted writeable again, the device replace
 127                  * operation continues.
 128                  */
 129         }
 130 }
 131
 132 #ifdef CONFIG_PRINTK
 133 /*
 134  * __btrfs_std_error decodes expected errors from the caller and
 135  * invokes the approciate error response.
 136  */
 137 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 138                        unsigned int line, int errno, const char *fmt, ...)
 139 {
 140         struct super_block *sb = fs_info->sb;
 141         const char *errstr;
 142
 143         /*
 144          * Special case: if the error is EROFS, and we're already
 145          * under MS_RDONLY, then it is safe here.
 146          */
 147         if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
 148                 return;
 149
 150         errstr = btrfs_decode_error(errno);
 151         if (fmt) {
 152                 struct va_format vaf;
 153                 va_list args;
 154
 155                 va_start(args, fmt);
 156                 vaf.fmt = fmt;
 157                 vaf.va = &args;
 158
 159                 printk(KERN_CRIT
 160                         "BTRFS: error (device %s) in %s:%d: errno=%d %s (%pV)\n",
 161                         sb->s_id, function, line, errno, errstr, &vaf);
 162                 va_end(args);
 163         } else {
 164                 printk(KERN_CRIT "BTRFS: error (device %s) in %s:%d: errno=%d %s\n",
 165                         sb->s_id, function, line, errno, errstr);
 166         }
 167
 168         /* Don't go through full error handling during mount */
 169         save_error_info(fs_info);
 170         if (sb->s_flags & MS_BORN)
 171                 btrfs_handle_error(fs_info);
 172 }
 173
 174 static const char * const logtypes[] = {
 175         "emergency",
 176         "alert",
 177         "critical",
 178         "error",
 179         "warning",
 180         "notice",
 181         "info",
 182         "debug",
 183 };
 184
 185 void btrfs_printk(const struct btrfs_fs_info *fs_info, const char *fmt, ...)
 186 {
 187         struct super_block *sb = fs_info->sb;
 188         char lvl[4];
 189         struct va_format vaf;
 190         va_list args;
 191         const char *type = logtypes[4];
 192         int kern_level;
 193
 194         va_start(args, fmt);
 195
 196         kern_level = printk_get_level(fmt);
 197         if (kern_level) {
 198                 size_t size = printk_skip_level(fmt) - fmt;
 199                 memcpy(lvl, fmt,  size);
 200                 lvl[size] = '\0';
 201                 fmt += size;
 202                 type = logtypes[kern_level - '0'];
 203         } else
 204                 *lvl = '\0';
 205
 206         vaf.fmt = fmt;
 207         vaf.va = &args;
 208
 209         printk("%sBTRFS %s (device %s): %pV\n", lvl, type, sb->s_id, &vaf);
 210
 211         va_end(args);
 212 }
 213
 214 #else
 215
 216 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 217                        unsigned int line, int errno, const char *fmt, ...)
 218 {
 219         struct super_block *sb = fs_info->sb;
 220
 221         /*
 222          * Special case: if the error is EROFS, and we're already
 223          * under MS_RDONLY, then it is safe here.
 224          */
 225         if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
 226                 return;
 227
 228         /* Don't go through full error handling during mount */
 229         if (sb->s_flags & MS_BORN) {
 230                 save_error_info(fs_info);
 231                 btrfs_handle_error(fs_info);
 232         }
 233 }
 234 #endif
 235
 236 /*
 237  * We only mark the transaction aborted and then set the file system read-only.
 238  * This will prevent new transactions from starting or trying to join this
 239  * one.
 240  *
 241  * This means that error recovery at the call site is limited to freeing
 242  * any local memory allocations and passing the error code up without
 243  * further cleanup. The transaction should complete as it normally would
 244  * in the call path but will return -EIO.
 245  *
 246  * We'll complete the cleanup in btrfs_end_transaction and
 247  * btrfs_commit_transaction.
 248  */
 249 void __btrfs_abort_transaction(struct btrfs_trans_handle *trans,
 250                                struct btrfs_root *root, const char *function,
 251                                unsigned int line, int errno)
 252 {
 253         /*
 254          * Report first abort since mount
 255          */
 256         if (!test_and_set_bit(BTRFS_FS_STATE_TRANS_ABORTED,
 257                                 &root->fs_info->fs_state)) {
 258                 WARN(1, KERN_DEBUG "BTRFS: Transaction aborted (error %d)\n",
 259                                 errno);
 260         }
 261         trans->aborted = errno;
 262         /* Nothing used. The other threads that have joined this
 263          * transaction may be able to continue. */
 264         if (!trans->blocks_used) {
 265                 const char *errstr;
 266
 267                 errstr = btrfs_decode_error(errno);
 268                 btrfs_warn(root->fs_info,
 269                            "%s:%d: Aborting unused transaction(%s).",
 270                            function, line, errstr);
 271                 return;
 272         }
 273         ACCESS_ONCE(trans->transaction->aborted) = errno;
 274         /* Wake up anybody who may be waiting on this transaction */
 275         wake_up(&root->fs_info->transaction_wait);
 276         wake_up(&root->fs_info->transaction_blocked_wait);
 277         __btrfs_std_error(root->fs_info, function, line, errno, NULL);
 278 }
 279 /*
 280  * __btrfs_panic decodes unexpected, fatal errors from the caller,
 281  * issues an alert, and either panics or BUGs, depending on mount options.
 282  */
 283 void __btrfs_panic(struct btrfs_fs_info *fs_info, const char *function,
 284                    unsigned int line, int errno, const char *fmt, ...)
 285 {
 286         char *s_id = "<unknown>";
 287         const char *errstr;
 288         struct va_format vaf = { .fmt = fmt };
 289         va_list args;
 290
 291         if (fs_info)
 292                 s_id = fs_info->sb->s_id;
 293
 294         va_start(args, fmt);
 295         vaf.va = &args;
 296
 297         errstr = btrfs_decode_error(errno);
 298         if (fs_info && (fs_info->mount_opt & BTRFS_MOUNT_PANIC_ON_FATAL_ERROR))
 299                 panic(KERN_CRIT "BTRFS panic (device %s) in %s:%d: %pV (errno=%d %s)\n",
 300                         s_id, function, line, &vaf, errno, errstr);
 301
 302         btrfs_crit(fs_info, "panic in %s:%d: %pV (errno=%d %s)",
 303                    function, line, &vaf, errno, errstr);
 304         va_end(args);
 305         /* Caller calls BUG() */
 306 }
 307
 308 static void btrfs_put_super(struct super_block *sb)
 309 {
 310         (void)close_ctree(btrfs_sb(sb)->tree_root);
 311         /* FIXME: need to fix VFS to return error? */
 312         /* AV: return it _where_?  ->put_super() can be triggered by any number
 313          * of async events, up to and including delivery of SIGKILL to the
 314          * last process that kept it busy.  Or segfault in the aforementioned
 315          * process...  Whom would you report that to?
 316          */
 317 }
 318
 319 enum {
 320         Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
 321         Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
 322         Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
 323         Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
 324         Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
 325         Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
 326         Opt_enospc_debug, Opt_subvolrootid, Opt_defrag, Opt_inode_cache,
 327         Opt_no_space_cache, Opt_recovery, Opt_skip_balance,
 328         Opt_check_integrity, Opt_check_integrity_including_extent_data,
 329         Opt_check_integrity_print_mask, Opt_fatal_errors, Opt_rescan_uuid_tree,
 330         Opt_commit_interval, Opt_barrier, Opt_nodefrag, Opt_nodiscard,
 331         Opt_noenospc_debug, Opt_noflushoncommit, Opt_acl, Opt_datacow,
 332         Opt_datasum, Opt_treelog, Opt_noinode_cache,
 333         Opt_err,
 334 };
 335
 336 static match_table_t tokens = {
 337         {Opt_degraded, "degraded"},
 338         {Opt_subvol, "subvol=%s"},
 339         {Opt_subvolid, "subvolid=%s"},
 340         {Opt_device, "device=%s"},
 341         {Opt_nodatasum, "nodatasum"},
 342         {Opt_datasum, "datasum"},
 343         {Opt_nodatacow, "nodatacow"},
 344         {Opt_datacow, "datacow"},
 345         {Opt_nobarrier, "nobarrier"},
 346         {Opt_barrier, "barrier"},
 347         {Opt_max_inline, "max_inline=%s"},
 348         {Opt_alloc_start, "alloc_start=%s"},
 349         {Opt_thread_pool, "thread_pool=%d"},
 350         {Opt_compress, "compress"},
 351         {Opt_compress_type, "compress=%s"},
 352         {Opt_compress_force, "compress-force"},
 353         {Opt_compress_force_type, "compress-force=%s"},
 354         {Opt_ssd, "ssd"},
 355         {Opt_ssd_spread, "ssd_spread"},
 356         {Opt_nossd, "nossd"},
 357         {Opt_acl, "acl"},
 358         {Opt_noacl, "noacl"},
 359         {Opt_notreelog, "notreelog"},
 360         {Opt_treelog, "treelog"},
 361         {Opt_flushoncommit, "flushoncommit"},
 362         {Opt_noflushoncommit, "noflushoncommit"},
 363         {Opt_ratio, "metadata_ratio=%d"},
 364         {Opt_discard, "discard"},
 365         {Opt_nodiscard, "nodiscard"},
 366         {Opt_space_cache, "space_cache"},
 367         {Opt_clear_cache, "clear_cache"},
 368         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
 369         {Opt_enospc_debug, "enospc_debug"},
 370         {Opt_noenospc_debug, "noenospc_debug"},
 371         {Opt_subvolrootid, "subvolrootid=%d"},
 372         {Opt_defrag, "autodefrag"},
 373         {Opt_nodefrag, "noautodefrag"},
 374         {Opt_inode_cache, "inode_cache"},
 375         {Opt_noinode_cache, "noinode_cache"},
 376         {Opt_no_space_cache, "nospace_cache"},
 377         {Opt_recovery, "recovery"},
 378         {Opt_skip_balance, "skip_balance"},
 379         {Opt_check_integrity, "check_int"},
 380         {Opt_check_integrity_including_extent_data, "check_int_data"},
 381         {Opt_check_integrity_print_mask, "check_int_print_mask=%d"},
 382         {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
 383         {Opt_fatal_errors, "fatal_errors=%s"},
 384         {Opt_commit_interval, "commit=%d"},
 385         {Opt_err, NULL},
 386 };
 387
 388 /*
 389  * Regular mount options parser.  Everything that is needed only when
 390  * reading in a new superblock is parsed here.
 391  * XXX JDM: This needs to be cleaned up for remount.
 392  */
 393 int btrfs_parse_options(struct btrfs_root *root, char *options)
 394 {
 395         struct btrfs_fs_info *info = root->fs_info;
 396         substring_t args[MAX_OPT_ARGS];
 397         char *p, *num, *orig = NULL;
 398         u64 cache_gen;
 399         int intarg;
 400         int ret = 0;
 401         char *compress_type;
 402         bool compress_force = false;
 403         bool compress = false;
 404
 405         cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy);
 406         if (cache_gen)
 407                 btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 408
 409         if (!options)
 410                 goto out;
 411
 412         /*
 413          * strsep changes the string, duplicate it because parse_options
 414          * gets called twice
 415          */
 416         options = kstrdup(options, GFP_NOFS);
 417         if (!options)
 418                 return -ENOMEM;
 419
 420         orig = options;
 421
 422         while ((p = strsep(&options, ",")) != NULL) {
 423                 int token;
 424                 if (!*p)
 425                         continue;
 426
 427                 token = match_token(p, tokens, args);
 428                 switch (token) {
 429                 case Opt_degraded:
 430                         btrfs_info(root->fs_info, "allowing degraded mounts");
 431                         btrfs_set_opt(info->mount_opt, DEGRADED);
 432                         break;
 433                 case Opt_subvol:
 434                 case Opt_subvolid:
 435                 case Opt_subvolrootid:
 436                 case Opt_device:
 437                         /*
 438                          * These are parsed by btrfs_parse_early_options
 439                          * and can be happily ignored here.
 440                          */
 441                         break;
 442                 case Opt_nodatasum:
 443                         btrfs_set_and_info(root, NODATASUM,
 444                                            "setting nodatasum");
 445                         break;
 446                 case Opt_datasum:
 447                         if (btrfs_test_opt(root, NODATASUM)) {
 448                                 if (btrfs_test_opt(root, NODATACOW))
 449                                         btrfs_info(root->fs_info, "setting datasum, datacow enabled");
 450                                 else
 451                                         btrfs_info(root->fs_info, "setting datasum");
 452                         }
 453                         btrfs_clear_opt(info->mount_opt, NODATACOW);
 454                         btrfs_clear_opt(info->mount_opt, NODATASUM);
 455                         break;
 456                 case Opt_nodatacow:
 457                         if (!btrfs_test_opt(root, NODATACOW)) {
 458                                 if (!btrfs_test_opt(root, COMPRESS) ||
 459                                     !btrfs_test_opt(root, FORCE_COMPRESS)) {
 460                                         btrfs_info(root->fs_info,
 461                                                    "setting nodatacow, compression disabled");
 462                                 } else {
 463                                         btrfs_info(root->fs_info, "setting nodatacow");
 464                                 }
 465                         }
 466                         btrfs_clear_opt(info->mount_opt, COMPRESS);
 467                         btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 468                         btrfs_set_opt(info->mount_opt, NODATACOW);
 469                         btrfs_set_opt(info->mount_opt, NODATASUM);
 470                         break;
 471                 case Opt_datacow:
 472                         btrfs_clear_and_info(root, NODATACOW,
 473                                              "setting datacow");
 474                         break;
 475                 case Opt_compress_force:
 476                 case Opt_compress_force_type:
 477                         compress_force = true;
 478                         /* Fallthrough */
 479                 case Opt_compress:
 480                 case Opt_compress_type:
 481                         compress = true;
 482                         if (token == Opt_compress ||
 483                             token == Opt_compress_force ||
 484                             strcmp(args[0].from, "zlib") == 0) {
 485                                 compress_type = "zlib";
 486                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
 487                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 488                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 489                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 490                         } else if (strcmp(args[0].from, "lzo") == 0) {
 491                                 compress_type = "lzo";
 492                                 info->compress_type = BTRFS_COMPRESS_LZO;
 493                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 494                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 495                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 496                                 btrfs_set_fs_incompat(info, COMPRESS_LZO);
 497                         } else if (strncmp(args[0].from, "no", 2) == 0) {
 498                                 compress_type = "no";
 499                                 btrfs_clear_opt(info->mount_opt, COMPRESS);
 500                                 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 501                                 compress_force = false;
 502                         } else {
 503                                 ret = -EINVAL;
 504                                 goto out;
 505                         }
 506
 507                         if (compress_force) {
 508                                 btrfs_set_and_info(root, FORCE_COMPRESS,
 509                                                    "force %s compression",
 510                                                    compress_type);
 511                         } else if (compress) {
 512                                 if (!btrfs_test_opt(root, COMPRESS))
 513                                         btrfs_info(root->fs_info,
 514                                                    "btrfs: use %s compression\n",
 515                                                    compress_type);
 516                         }
 517                         break;
 518                 case Opt_ssd:
 519                         btrfs_set_and_info(root, SSD,
 520                                            "use ssd allocation scheme");
 521                         break;
 522                 case Opt_ssd_spread:
 523                         btrfs_set_and_info(root, SSD_SPREAD,
 524                                            "use spread ssd allocation scheme");
 525                         break;
 526                 case Opt_nossd:
 527                         btrfs_clear_and_info(root, NOSSD,
 528                                              "not using ssd allocation scheme");
 529                         btrfs_clear_opt(info->mount_opt, SSD);
 530                         break;
 531                 case Opt_barrier:
 532                         btrfs_clear_and_info(root, NOBARRIER,
 533                                              "turning on barriers");
 534                         break;
 535                 case Opt_nobarrier:
 536                         btrfs_set_and_info(root, NOBARRIER,
 537                                            "turning off barriers");
 538                         break;
 539                 case Opt_thread_pool:
 540                         ret = match_int(&args[0], &intarg);
 541                         if (ret) {
 542                                 goto out;
 543                         } else if (intarg > 0) {
 544                                 info->thread_pool_size = intarg;
 545                         } else {
 546                                 ret = -EINVAL;
 547                                 goto out;
 548                         }
 549                         break;
 550                 case Opt_max_inline:
 551                         num = match_strdup(&args[0]);
 552                         if (num) {
 553                                 info->max_inline = memparse(num, NULL);
 554                                 kfree(num);
 555
 556                                 if (info->max_inline) {
 557                                         info->max_inline = min_t(u64,
 558                                                 info->max_inline,
 559                                                 root->sectorsize);
 560                                 }
 561                                 btrfs_info(root->fs_info, "max_inline at %llu",
 562                                         info->max_inline);
 563                         } else {
 564                                 ret = -ENOMEM;
 565                                 goto out;
 566                         }
 567                         break;
 568                 case Opt_alloc_start:
 569                         num = match_strdup(&args[0]);
 570                         if (num) {
 571                                 mutex_lock(&info->chunk_mutex);
 572                                 info->alloc_start = memparse(num, NULL);
 573                                 mutex_unlock(&info->chunk_mutex);
 574                                 kfree(num);
 575                                 btrfs_info(root->fs_info, "allocations start at %llu",
 576                                         info->alloc_start);
 577                         } else {
 578                                 ret = -ENOMEM;
 579                                 goto out;
 580                         }
 581                         break;
 582                 case Opt_acl:
 583                         root->fs_info->sb->s_flags |= MS_POSIXACL;
 584                         break;
 585                 case Opt_noacl:
 586                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
 587                         break;
 588                 case Opt_notreelog:
 589                         btrfs_set_and_info(root, NOTREELOG,
 590                                            "disabling tree log");
 591                         break;
 592                 case Opt_treelog:
 593                         btrfs_clear_and_info(root, NOTREELOG,
 594                                              "enabling tree log");
 595                         break;
 596                 case Opt_flushoncommit:
 597                         btrfs_set_and_info(root, FLUSHONCOMMIT,
 598                                            "turning on flush-on-commit");
 599                         break;
 600                 case Opt_noflushoncommit:
 601                         btrfs_clear_and_info(root, FLUSHONCOMMIT,
 602                                              "turning off flush-on-commit");
 603                         break;
 604                 case Opt_ratio:
 605                         ret = match_int(&args[0], &intarg);
 606                         if (ret) {
 607                                 goto out;
 608                         } else if (intarg >= 0) {
 609                                 info->metadata_ratio = intarg;
 610                                 btrfs_info(root->fs_info, "metadata ratio %d",
 611                                        info->metadata_ratio);
 612                         } else {
 613                                 ret = -EINVAL;
 614                                 goto out;
 615                         }
 616                         break;
 617                 case Opt_discard:
 618                         btrfs_set_and_info(root, DISCARD,
 619                                            "turning on discard");
 620                         break;
 621                 case Opt_nodiscard:
 622                         btrfs_clear_and_info(root, DISCARD,
 623                                              "turning off discard");
 624                         break;
 625                 case Opt_space_cache:
 626                         btrfs_set_and_info(root, SPACE_CACHE,
 627                                            "enabling disk space caching");
 628                         break;
 629                 case Opt_rescan_uuid_tree:
 630                         btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
 631                         break;
 632                 case Opt_no_space_cache:
 633                         btrfs_clear_and_info(root, SPACE_CACHE,
 634                                              "disabling disk space caching");
 635                         break;
 636                 case Opt_inode_cache:
 637                         btrfs_set_and_info(root, CHANGE_INODE_CACHE,
 638                                            "enabling inode map caching");
 639                         break;
 640                 case Opt_noinode_cache:
 641                         btrfs_clear_and_info(root, CHANGE_INODE_CACHE,
 642                                              "disabling inode map caching");
 643                         break;
 644                 case Opt_clear_cache:
 645                         btrfs_set_and_info(root, CLEAR_CACHE,
 646                                            "force clearing of disk cache");
 647                         break;
 648                 case Opt_user_subvol_rm_allowed:
 649                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
 650                         break;
 651                 case Opt_enospc_debug:
 652                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
 653                         break;
 654                 case Opt_noenospc_debug:
 655                         btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
 656                         break;
 657                 case Opt_defrag:
 658                         btrfs_set_and_info(root, AUTO_DEFRAG,
 659                                            "enabling auto defrag");
 660                         break;
 661                 case Opt_nodefrag:
 662                         btrfs_clear_and_info(root, AUTO_DEFRAG,
 663                                              "disabling auto defrag");
 664                         break;
 665                 case Opt_recovery:
 666                         btrfs_info(root->fs_info, "enabling auto recovery");
 667                         btrfs_set_opt(info->mount_opt, RECOVERY);
 668                         break;
 669                 case Opt_skip_balance:
 670                         btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
 671                         break;
 672 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
 673                 case Opt_check_integrity_including_extent_data:
 674                         btrfs_info(root->fs_info,
 675                                    "enabling check integrity including extent data");
 676                         btrfs_set_opt(info->mount_opt,
 677                                       CHECK_INTEGRITY_INCLUDING_EXTENT_DATA);
 678                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 679                         break;
 680                 case Opt_check_integrity:
 681                         btrfs_info(root->fs_info, "enabling check integrity");
 682                         btrfs_set_opt(info->mount_opt, CHECK_INTEGRITY);
 683                         break;
 684                 case Opt_check_integrity_print_mask:
 685                         ret = match_int(&args[0], &intarg);
 686                         if (ret) {
 687                                 goto out;
 688                         } else if (intarg >= 0) {
 689                                 info->check_integrity_print_mask = intarg;
 690                                 btrfs_info(root->fs_info, "check_integrity_print_mask 0x%x",
 691                                        info->check_integrity_print_mask);
 692                         } else {
 693                                 ret = -EINVAL;
 694                                 goto out;
 695                         }
 696                         break;
 697 #else
 698                 case Opt_check_integrity_including_extent_data:
 699                 case Opt_check_integrity:
 700                 case Opt_check_integrity_print_mask:
 701                         btrfs_err(root->fs_info,
 702                                 "support for check_integrity* not compiled in!");
 703                         ret = -EINVAL;
 704                         goto out;
 705 #endif
 706                 case Opt_fatal_errors:
 707                         if (strcmp(args[0].from, "panic") == 0)
 708                                 btrfs_set_opt(info->mount_opt,
 709                                               PANIC_ON_FATAL_ERROR);
 710                         else if (strcmp(args[0].from, "bug") == 0)
 711                                 btrfs_clear_opt(info->mount_opt,
 712                                               PANIC_ON_FATAL_ERROR);
 713                         else {
 714                                 ret = -EINVAL;
 715                                 goto out;
 716                         }
 717                         break;
 718                 case Opt_commit_interval:
 719                         intarg = 0;
 720                         ret = match_int(&args[0], &intarg);
 721                         if (ret < 0) {
 722                                 btrfs_err(root->fs_info, "invalid commit interval");
 723                                 ret = -EINVAL;
 724                                 goto out;
 725                         }
 726                         if (intarg > 0) {
 727                                 if (intarg > 300) {
 728                                         btrfs_warn(root->fs_info, "excessive commit interval %d",
 729                                                         intarg);
 730                                 }
 731                                 info->commit_interval = intarg;
 732                         } else {
 733                                 btrfs_info(root->fs_info, "using default commit interval %ds",
 734                                     BTRFS_DEFAULT_COMMIT_INTERVAL);
 735                                 info->commit_interval = BTRFS_DEFAULT_COMMIT_INTERVAL;
 736                         }
 737                         break;
 738                 case Opt_err:
 739                         btrfs_info(root->fs_info, "unrecognized mount option '%s'", p);
 740                         ret = -EINVAL;
 741                         goto out;
 742                 default:
 743                         break;
 744                 }
 745         }
 746 out:
 747         if (!ret && btrfs_test_opt(root, SPACE_CACHE))
 748                 btrfs_info(root->fs_info, "disk space caching is enabled");
 749         kfree(orig);
 750         return ret;
 751 }
 752
 753 /*
 754  * Parse mount options that are required early in the mount process.
 755  *
 756  * All other options will be parsed on much later in the mount process and
 757  * only when we need to allocate a new super block.
 758  */
 759 static int btrfs_parse_early_options(const char *options, fmode_t flags,
 760                 void *holder, char **subvol_name, u64 *subvol_objectid,
 761                 struct btrfs_fs_devices **fs_devices)
 762 {
 763         substring_t args[MAX_OPT_ARGS];
 764         char *device_name, *opts, *orig, *p;
 765         char *num = NULL;
 766         int error = 0;
 767
 768         if (!options)
 769                 return 0;
 770
 771         /*
 772          * strsep changes the string, duplicate it because parse_options
 773          * gets called twice
 774          */
 775         opts = kstrdup(options, GFP_KERNEL);
 776         if (!opts)
 777                 return -ENOMEM;
 778         orig = opts;
 779
 780         while ((p = strsep(&opts, ",")) != NULL) {
 781                 int token;
 782                 if (!*p)
 783                         continue;
 784
 785                 token = match_token(p, tokens, args);
 786                 switch (token) {
 787                 case Opt_subvol:
 788                         kfree(*subvol_name);
 789                         *subvol_name = match_strdup(&args[0]);
 790                         if (!*subvol_name) {
 791                                 error = -ENOMEM;
 792                                 goto out;
 793                         }
 794                         break;
 795                 case Opt_subvolid:
 796                         num = match_strdup(&args[0]);
 797                         if (num) {
 798                                 *subvol_objectid = memparse(num, NULL);
 799                                 kfree(num);
 800                                 /* we want the original fs_tree */
 801                                 if (!*subvol_objectid)
 802                                         *subvol_objectid =
 803                                                 BTRFS_FS_TREE_OBJECTID;
 804                         } else {
 805                                 error = -EINVAL;
 806                                 goto out;
 807                         }
 808                         break;
 809                 case Opt_subvolrootid:
 810                         printk(KERN_WARNING
 811                                 "BTRFS: 'subvolrootid' mount option is deprecated and has "
 812                                 "no effect\n");
 813                         break;
 814                 case Opt_device:
 815                         device_name = match_strdup(&args[0]);
 816                         if (!device_name) {
 817                                 error = -ENOMEM;
 818                                 goto out;
 819                         }
 820                         error = btrfs_scan_one_device(device_name,
 821                                         flags, holder, fs_devices);
 822                         kfree(device_name);
 823                         if (error)
 824                                 goto out;
 825                         break;
 826                 default:
 827                         break;
 828                 }
 829         }
 830
 831 out:
 832         kfree(orig);
 833         return error;
 834 }
 835
 836 static struct dentry *get_default_root(struct super_block *sb,
 837                                        u64 subvol_objectid)
 838 {
 839         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 840         struct btrfs_root *root = fs_info->tree_root;
 841         struct btrfs_root *new_root;
 842         struct btrfs_dir_item *di;
 843         struct btrfs_path *path;
 844         struct btrfs_key location;
 845         struct inode *inode;
 846         struct dentry *dentry;
 847         u64 dir_id;
 848         int new = 0;
 849
 850         /*
 851          * We have a specific subvol we want to mount, just setup location and
 852          * go look up the root.
 853          */
 854         if (subvol_objectid) {
 855                 location.objectid = subvol_objectid;
 856                 location.type = BTRFS_ROOT_ITEM_KEY;
 857                 location.offset = (u64)-1;
 858                 goto find_root;
 859         }
 860
 861         path = btrfs_alloc_path();
 862         if (!path)
 863                 return ERR_PTR(-ENOMEM);
 864         path->leave_spinning = 1;
 865
 866         /*
 867          * Find the "default" dir item which points to the root item that we
 868          * will mount by default if we haven't been given a specific subvolume
 869          * to mount.
 870          */
 871         dir_id = btrfs_super_root_dir(fs_info->super_copy);
 872         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
 873         if (IS_ERR(di)) {
 874                 btrfs_free_path(path);
 875                 return ERR_CAST(di);
 876         }
 877         if (!di) {
 878                 /*
 879                  * Ok the default dir item isn't there.  This is weird since
 880                  * it's always been there, but don't freak out, just try and
 881                  * mount to root most subvolume.
 882                  */
 883                 btrfs_free_path(path);
 884                 dir_id = BTRFS_FIRST_FREE_OBJECTID;
 885                 new_root = fs_info->fs_root;
 886                 goto setup_root;
 887         }
 888
 889         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 890         btrfs_free_path(path);
 891
 892 find_root:
 893         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
 894         if (IS_ERR(new_root))
 895                 return ERR_CAST(new_root);
 896
 897         dir_id = btrfs_root_dirid(&new_root->root_item);
 898 setup_root:
 899         location.objectid = dir_id;
 900         location.type = BTRFS_INODE_ITEM_KEY;
 901         location.offset = 0;
 902
 903         inode = btrfs_iget(sb, &location, new_root, &new);
 904         if (IS_ERR(inode))
 905                 return ERR_CAST(inode);
 906
 907         /*
 908          * If we're just mounting the root most subvol put the inode and return
 909          * a reference to the dentry.  We will have already gotten a reference
 910          * to the inode in btrfs_fill_super so we're good to go.
 911          */
 912         if (!new && sb->s_root->d_inode == inode) {
 913                 iput(inode);
 914                 return dget(sb->s_root);
 915         }
 916
 917         dentry = d_obtain_alias(inode);
 918         if (!IS_ERR(dentry)) {
 919                 spin_lock(&dentry->d_lock);
 920                 dentry->d_flags &= ~DCACHE_DISCONNECTED;
 921                 spin_unlock(&dentry->d_lock);
 922         }
 923         return dentry;
 924 }
 925
 926 static int btrfs_fill_super(struct super_block *sb,
 927                             struct btrfs_fs_devices *fs_devices,
 928                             void *data, int silent)
 929 {
 930         struct inode *inode;
 931         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 932         struct btrfs_key key;
 933         int err;
 934
 935         sb->s_maxbytes = MAX_LFS_FILESIZE;
 936         sb->s_magic = BTRFS_SUPER_MAGIC;
 937         sb->s_op = &btrfs_super_ops;
 938         sb->s_d_op = &btrfs_dentry_operations;
 939         sb->s_export_op = &btrfs_export_ops;
 940         sb->s_xattr = btrfs_xattr_handlers;
 941         sb->s_time_gran = 1;
 942 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 943         sb->s_flags |= MS_POSIXACL;
 944 #endif
 945         sb->s_flags |= MS_I_VERSION;
 946         err = open_ctree(sb, fs_devices, (char *)data);
 947         if (err) {
 948                 printk(KERN_ERR "BTRFS: open_ctree failed\n");
 949                 return err;
 950         }
 951
 952         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 953         key.type = BTRFS_INODE_ITEM_KEY;
 954         key.offset = 0;
 955         inode = btrfs_iget(sb, &key, fs_info->fs_root, NULL);
 956         if (IS_ERR(inode)) {
 957                 err = PTR_ERR(inode);
 958                 goto fail_close;
 959         }
 960
 961         sb->s_root = d_make_root(inode);
 962         if (!sb->s_root) {
 963                 err = -ENOMEM;
 964                 goto fail_close;
 965         }
 966
 967         save_mount_options(sb, data);
 968         cleancache_init_fs(sb);
 969         sb->s_flags |= MS_ACTIVE;
 970         return 0;
 971
 972 fail_close:
 973         close_ctree(fs_info->tree_root);
 974         return err;
 975 }
 976
 977 int btrfs_sync_fs(struct super_block *sb, int wait)
 978 {
 979         struct btrfs_trans_handle *trans;
 980         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
 981         struct btrfs_root *root = fs_info->tree_root;
 982
 983         trace_btrfs_sync_fs(wait);
 984
 985         if (!wait) {
 986                 filemap_flush(fs_info->btree_inode->i_mapping);
 987                 return 0;
 988         }
 989
 990         btrfs_wait_ordered_roots(fs_info, -1);
 991
 992         trans = btrfs_attach_transaction_barrier(root);
 993         if (IS_ERR(trans)) {
 994                 /* no transaction, don't bother */
 995                 if (PTR_ERR(trans) == -ENOENT)
 996                         return 0;
 997                 return PTR_ERR(trans);
 998         }
 999         return btrfs_commit_transaction(trans, root);
1000 }
1001
1002 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1003 {
1004         struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1005         struct btrfs_root *root = info->tree_root;
1006         char *compress_type;
1007
1008         if (btrfs_test_opt(root, DEGRADED))
1009                 seq_puts(seq, ",degraded");
1010         if (btrfs_test_opt(root, NODATASUM))
1011                 seq_puts(seq, ",nodatasum");
1012         if (btrfs_test_opt(root, NODATACOW))
1013                 seq_puts(seq, ",nodatacow");
1014         if (btrfs_test_opt(root, NOBARRIER))
1015                 seq_puts(seq, ",nobarrier");
1016         if (info->max_inline != 8192 * 1024)
1017                 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1018         if (info->alloc_start != 0)
1019                 seq_printf(seq, ",alloc_start=%llu", info->alloc_start);
1020         if (info->thread_pool_size !=  min_t(unsigned long,
1021                                              num_online_cpus() + 2, 8))
1022                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
1023         if (btrfs_test_opt(root, COMPRESS)) {
1024                 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
1025                         compress_type = "zlib";
1026                 else
1027                         compress_type = "lzo";
1028                 if (btrfs_test_opt(root, FORCE_COMPRESS))
1029                         seq_printf(seq, ",compress-force=%s", compress_type);
1030                 else
1031                         seq_printf(seq, ",compress=%s", compress_type);
1032         }
1033         if (btrfs_test_opt(root, NOSSD))
1034                 seq_puts(seq, ",nossd");
1035         if (btrfs_test_opt(root, SSD_SPREAD))
1036                 seq_puts(seq, ",ssd_spread");
1037         else if (btrfs_test_opt(root, SSD))
1038                 seq_puts(seq, ",ssd");
1039         if (btrfs_test_opt(root, NOTREELOG))
1040                 seq_puts(seq, ",notreelog");
1041         if (btrfs_test_opt(root, FLUSHONCOMMIT))
1042                 seq_puts(seq, ",flushoncommit");
1043         if (btrfs_test_opt(root, DISCARD))
1044                 seq_puts(seq, ",discard");
1045         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
1046                 seq_puts(seq, ",noacl");
1047         if (btrfs_test_opt(root, SPACE_CACHE))
1048                 seq_puts(seq, ",space_cache");
1049         else
1050                 seq_puts(seq, ",nospace_cache");
1051         if (btrfs_test_opt(root, RESCAN_UUID_TREE))
1052                 seq_puts(seq, ",rescan_uuid_tree");
1053         if (btrfs_test_opt(root, CLEAR_CACHE))
1054                 seq_puts(seq, ",clear_cache");
1055         if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
1056                 seq_puts(seq, ",user_subvol_rm_allowed");
1057         if (btrfs_test_opt(root, ENOSPC_DEBUG))
1058                 seq_puts(seq, ",enospc_debug");
1059         if (btrfs_test_opt(root, AUTO_DEFRAG))
1060                 seq_puts(seq, ",autodefrag");
1061         if (btrfs_test_opt(root, INODE_MAP_CACHE))
1062                 seq_puts(seq, ",inode_cache");
1063         if (btrfs_test_opt(root, SKIP_BALANCE))
1064                 seq_puts(seq, ",skip_balance");
1065         if (btrfs_test_opt(root, RECOVERY))
1066                 seq_puts(seq, ",recovery");
1067 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1068         if (btrfs_test_opt(root, CHECK_INTEGRITY_INCLUDING_EXTENT_DATA))
1069                 seq_puts(seq, ",check_int_data");
1070         else if (btrfs_test_opt(root, CHECK_INTEGRITY))
1071                 seq_puts(seq, ",check_int");
1072         if (info->check_integrity_print_mask)
1073                 seq_printf(seq, ",check_int_print_mask=%d",
1074                                 info->check_integrity_print_mask);
1075 #endif
1076         if (info->metadata_ratio)
1077                 seq_printf(seq, ",metadata_ratio=%d",
1078                                 info->metadata_ratio);
1079         if (btrfs_test_opt(root, PANIC_ON_FATAL_ERROR))
1080                 seq_puts(seq, ",fatal_errors=panic");
1081         if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1082                 seq_printf(seq, ",commit=%d", info->commit_interval);
1083         return 0;
1084 }
1085
1086 static int btrfs_test_super(struct super_block *s, void *data)
1087 {
1088         struct btrfs_fs_info *p = data;
1089         struct btrfs_fs_info *fs_info = btrfs_sb(s);
1090
1091         return fs_info->fs_devices == p->fs_devices;
1092 }
1093
1094 static int btrfs_set_super(struct super_block *s, void *data)
1095 {
1096         int err = set_anon_super(s, data);
1097         if (!err)
1098                 s->s_fs_info = data;
1099         return err;
1100 }
1101
1102 /*
1103  * subvolumes are identified by ino 256
1104  */
1105 static inline int is_subvolume_inode(struct inode *inode)
1106 {
1107         if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1108                 return 1;
1109         return 0;
1110 }
1111
1112 /*
1113  * This will strip out the subvol=%s argument for an argument string and add
1114  * subvolid=0 to make sure we get the actual tree root for path walking to the
1115  * subvol we want.
1116  */
1117 static char *setup_root_args(char *args)
1118 {
1119         unsigned len = strlen(args) + 2 + 1;
1120         char *src, *dst, *buf;
1121
1122         /*
1123          * We need the same args as before, but with this substitution:
1124          * s!subvol=[^,]+!subvolid=0!
1125          *
1126          * Since the replacement string is up to 2 bytes longer than the
1127          * original, allocate strlen(args) + 2 + 1 bytes.
1128          */
1129
1130         src = strstr(args, "subvol=");
1131         /* This shouldn't happen, but just in case.. */
1132         if (!src)
1133                 return NULL;
1134
1135         buf = dst = kmalloc(len, GFP_NOFS);
1136         if (!buf)
1137                 return NULL;
1138
1139         /*
1140          * If the subvol= arg is not at the start of the string,
1141          * copy whatever precedes it into buf.
1142          */
1143         if (src != args) {
1144                 *src++ = '\0';
1145                 strcpy(buf, args);
1146                 dst += strlen(args);
1147         }
1148
1149         strcpy(dst, "subvolid=0");
1150         dst += strlen("subvolid=0");
1151
1152         /*
1153          * If there is a "," after the original subvol=... string,
1154          * copy that suffix into our buffer.  Otherwise, we're done.
1155          */
1156         src = strchr(src, ',');
1157         if (src)
1158                 strcpy(dst, src);
1159
1160         return buf;
1161 }
1162
1163 static struct dentry *mount_subvol(const char *subvol_name, int flags,
1164                                    const char *device_name, char *data)
1165 {
1166         struct dentry *root;
1167         struct vfsmount *mnt;
1168         char *newargs;
1169
1170         newargs = setup_root_args(data);
1171         if (!newargs)
1172                 return ERR_PTR(-ENOMEM);
1173         mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
1174                              newargs);
1175
1176         if (PTR_RET(mnt) == -EBUSY) {
1177                 if (flags & MS_RDONLY) {
1178                         mnt = vfs_kern_mount(&btrfs_fs_type, flags & ~MS_RDONLY, device_name,
1179                                              newargs);
1180                 } else {
1181                         int r;
1182                         mnt = vfs_kern_mount(&btrfs_fs_type, flags | MS_RDONLY, device_name,
1183                                              newargs);
1184                         if (IS_ERR(mnt)) {
1185                                 kfree(newargs);
1186                                 return ERR_CAST(mnt);
1187                         }
1188
1189                         r = btrfs_remount(mnt->mnt_sb, &flags, NULL);
1190                         if (r < 0) {
1191                                 /* FIXME: release vfsmount mnt ??*/
1192                                 kfree(newargs);
1193                                 return ERR_PTR(r);
1194                         }
1195                 }
1196         }
1197
1198         kfree(newargs);
1199
1200         if (IS_ERR(mnt))
1201                 return ERR_CAST(mnt);
1202
1203         root = mount_subtree(mnt, subvol_name);
1204
1205         if (!IS_ERR(root) && !is_subvolume_inode(root->d_inode)) {
1206                 struct super_block *s = root->d_sb;
1207                 dput(root);
1208                 root = ERR_PTR(-EINVAL);
1209                 deactivate_locked_super(s);
1210                 printk(KERN_ERR "BTRFS: '%s' is not a valid subvolume\n",
1211                                 subvol_name);
1212         }
1213
1214         return root;
1215 }
1216
1217 /*
1218  * Find a superblock for the given device / mount point.
1219  *
1220  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
1221  *        for multiple device setup.  Make sure to keep it in sync.
1222  */
1223 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1224                 const char *device_name, void *data)
1225 {
1226         struct block_device *bdev = NULL;
1227         struct super_block *s;
1228         struct dentry *root;
1229         struct btrfs_fs_devices *fs_devices = NULL;
1230         struct btrfs_fs_info *fs_info = NULL;
1231         fmode_t mode = FMODE_READ;
1232         char *subvol_name = NULL;
1233         u64 subvol_objectid = 0;
1234         int error = 0;
1235
1236         if (!(flags & MS_RDONLY))
1237                 mode |= FMODE_WRITE;
1238
1239         error = btrfs_parse_early_options(data, mode, fs_type,
1240                                           &subvol_name, &subvol_objectid,
1241                                           &fs_devices);
1242         if (error) {
1243                 kfree(subvol_name);
1244                 return ERR_PTR(error);
1245         }
1246
1247         if (subvol_name) {
1248                 root = mount_subvol(subvol_name, flags, device_name, data);
1249                 kfree(subvol_name);
1250                 return root;
1251         }
1252
1253         error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
1254         if (error)
1255                 return ERR_PTR(error);
1256
1257         /*
1258          * Setup a dummy root and fs_info for test/set super.  This is because
1259          * we don't actually fill this stuff out until open_ctree, but we need
1260          * it for searching for existing supers, so this lets us do that and
1261          * then open_ctree will properly initialize everything later.
1262          */
1263         fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
1264         if (!fs_info)
1265                 return ERR_PTR(-ENOMEM);
1266
1267         fs_info->fs_devices = fs_devices;
1268
1269         fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1270         fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_NOFS);
1271         if (!fs_info->super_copy || !fs_info->super_for_commit) {
1272                 error = -ENOMEM;
1273                 goto error_fs_info;
1274         }
1275
1276         error = btrfs_open_devices(fs_devices, mode, fs_type);
1277         if (error)
1278                 goto error_fs_info;
1279
1280         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
1281                 error = -EACCES;
1282                 goto error_close_devices;
1283         }
1284
1285         bdev = fs_devices->latest_bdev;
1286         s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | MS_NOSEC,
1287                  fs_info);
1288         if (IS_ERR(s)) {
1289                 error = PTR_ERR(s);
1290                 goto error_close_devices;
1291         }
1292
1293         if (s->s_root) {
1294                 btrfs_close_devices(fs_devices);
1295                 free_fs_info(fs_info);
1296                 if ((flags ^ s->s_flags) & MS_RDONLY)
1297                         error = -EBUSY;
1298         } else {
1299                 char b[BDEVNAME_SIZE];
1300
1301                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
1302                 btrfs_sb(s)->bdev_holder = fs_type;
1303                 error = btrfs_fill_super(s, fs_devices, data,
1304                                          flags & MS_SILENT ? 1 : 0);
1305         }
1306
1307         root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error);
1308         if (IS_ERR(root))
1309                 deactivate_locked_super(s);
1310
1311         return root;
1312
1313 error_close_devices:
1314         btrfs_close_devices(fs_devices);
1315 error_fs_info:
1316         free_fs_info(fs_info);
1317         return ERR_PTR(error);
1318 }
1319
1320 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1321                                      int new_pool_size, int old_pool_size)
1322 {
1323         if (new_pool_size == old_pool_size)
1324                 return;
1325
1326         fs_info->thread_pool_size = new_pool_size;
1327
1328         btrfs_info(fs_info, "resize thread pool %d -> %d",
1329                old_pool_size, new_pool_size);
1330
1331         btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1332         btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1333         btrfs_workqueue_set_max(fs_info->submit_workers, new_pool_size);
1334         btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1335         btrfs_workqueue_set_max(fs_info->endio_workers, new_pool_size);
1336         btrfs_workqueue_set_max(fs_info->endio_meta_workers, new_pool_size);
1337         btrfs_workqueue_set_max(fs_info->endio_meta_write_workers,
1338                                 new_pool_size);
1339         btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1340         btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1341         btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1342         btrfs_workqueue_set_max(fs_info->readahead_workers, new_pool_size);
1343         btrfs_workqueue_set_max(fs_info->scrub_wr_completion_workers,
1344                                 new_pool_size);
1345 }
1346
1347 static inline void btrfs_remount_prepare(struct btrfs_fs_info *fs_info)
1348 {
1349         set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1350 }
1351
1352 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1353                                        unsigned long old_opts, int flags)
1354 {
1355         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1356             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1357              (flags & MS_RDONLY))) {
1358                 /* wait for any defraggers to finish */
1359                 wait_event(fs_info->transaction_wait,
1360                            (atomic_read(&fs_info->defrag_running) == 0));
1361                 if (flags & MS_RDONLY)
1362                         sync_filesystem(fs_info->sb);
1363         }
1364 }
1365
1366 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1367                                          unsigned long old_opts)
1368 {
1369         /*
1370          * We need cleanup all defragable inodes if the autodefragment is
1371          * close or the fs is R/O.
1372          */
1373         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1374             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1375              (fs_info->sb->s_flags & MS_RDONLY))) {
1376                 btrfs_cleanup_defrag_inodes(fs_info);
1377         }
1378
1379         clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1380 }
1381
1382 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1383 {
1384         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1385         struct btrfs_root *root = fs_info->tree_root;
1386         unsigned old_flags = sb->s_flags;
1387         unsigned long old_opts = fs_info->mount_opt;
1388         unsigned long old_compress_type = fs_info->compress_type;
1389         u64 old_max_inline = fs_info->max_inline;
1390         u64 old_alloc_start = fs_info->alloc_start;
1391         int old_thread_pool_size = fs_info->thread_pool_size;
1392         unsigned int old_metadata_ratio = fs_info->metadata_ratio;
1393         int ret;
1394
1395         sync_filesystem(sb);
1396         btrfs_remount_prepare(fs_info);
1397
1398         ret = btrfs_parse_options(root, data);
1399         if (ret) {
1400                 ret = -EINVAL;
1401                 goto restore;
1402         }
1403
1404         btrfs_remount_begin(fs_info, old_opts, *flags);
1405         btrfs_resize_thread_pool(fs_info,
1406                 fs_info->thread_pool_size, old_thread_pool_size);
1407
1408         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
1409                 goto out;
1410
1411         if (*flags & MS_RDONLY) {
1412                 /*
1413                  * this also happens on 'umount -rf' or on shutdown, when
1414                  * the filesystem is busy.
1415                  */
1416
1417                 /* wait for the uuid_scan task to finish */
1418                 down(&fs_info->uuid_tree_rescan_sem);
1419                 /* avoid complains from lockdep et al. */
1420                 up(&fs_info->uuid_tree_rescan_sem);
1421
1422                 sb->s_flags |= MS_RDONLY;
1423
1424                 btrfs_dev_replace_suspend_for_unmount(fs_info);
1425                 btrfs_scrub_cancel(fs_info);
1426                 btrfs_pause_balance(fs_info);
1427
1428                 ret = btrfs_commit_super(root);
1429                 if (ret)
1430                         goto restore;
1431         } else {
1432                 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1433                         btrfs_err(fs_info,
1434                                 "Remounting read-write after error is not allowed");
1435                         ret = -EINVAL;
1436                         goto restore;
1437                 }
1438                 if (fs_info->fs_devices->rw_devices == 0) {
1439                         ret = -EACCES;
1440                         goto restore;
1441                 }
1442
1443                 if (fs_info->fs_devices->missing_devices >
1444                      fs_info->num_tolerated_disk_barrier_failures &&
1445                     !(*flags & MS_RDONLY)) {
1446                         btrfs_warn(fs_info,
1447                                 "too many missing devices, writeable remount is not allowed");
1448                         ret = -EACCES;
1449                         goto restore;
1450                 }
1451
1452                 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1453                         ret = -EINVAL;
1454                         goto restore;
1455                 }
1456
1457                 ret = btrfs_cleanup_fs_roots(fs_info);
1458                 if (ret)
1459                         goto restore;
1460
1461                 /* recover relocation */
1462                 ret = btrfs_recover_relocation(root);
1463                 if (ret)
1464                         goto restore;
1465
1466                 ret = btrfs_resume_balance_async(fs_info);
1467                 if (ret)
1468                         goto restore;
1469
1470                 ret = btrfs_resume_dev_replace_async(fs_info);
1471                 if (ret) {
1472                         btrfs_warn(fs_info, "failed to resume dev_replace");
1473                         goto restore;
1474                 }
1475
1476                 if (!fs_info->uuid_root) {
1477                         btrfs_info(fs_info, "creating UUID tree");
1478                         ret = btrfs_create_uuid_tree(fs_info);
1479                         if (ret) {
1480                                 btrfs_warn(fs_info, "failed to create the UUID tree %d", ret);
1481                                 goto restore;
1482                         }
1483                 }
1484                 sb->s_flags &= ~MS_RDONLY;
1485         }
1486 out:
1487         wake_up_process(fs_info->transaction_kthread);
1488         btrfs_remount_cleanup(fs_info, old_opts);
1489         return 0;
1490
1491 restore:
1492         /* We've hit an error - don't reset MS_RDONLY */
1493         if (sb->s_flags & MS_RDONLY)
1494                 old_flags |= MS_RDONLY;
1495         sb->s_flags = old_flags;
1496         fs_info->mount_opt = old_opts;
1497         fs_info->compress_type = old_compress_type;
1498         fs_info->max_inline = old_max_inline;
1499         mutex_lock(&fs_info->chunk_mutex);
1500         fs_info->alloc_start = old_alloc_start;
1501         mutex_unlock(&fs_info->chunk_mutex);
1502         btrfs_resize_thread_pool(fs_info,
1503                 old_thread_pool_size, fs_info->thread_pool_size);
1504         fs_info->metadata_ratio = old_metadata_ratio;
1505         btrfs_remount_cleanup(fs_info, old_opts);
1506         return ret;
1507 }
1508
1509 /* Used to sort the devices by max_avail(descending sort) */
1510 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
1511                                        const void *dev_info2)
1512 {
1513         if (((struct btrfs_device_info *)dev_info1)->max_avail >
1514             ((struct btrfs_device_info *)dev_info2)->max_avail)
1515                 return -1;
1516         else if (((struct btrfs_device_info *)dev_info1)->max_avail <
1517                  ((struct btrfs_device_info *)dev_info2)->max_avail)
1518                 return 1;
1519         else
1520         return 0;
1521 }
1522
1523 /*
1524  * sort the devices by max_avail, in which max free extent size of each device
1525  * is stored.(Descending Sort)
1526  */
1527 static inline void btrfs_descending_sort_devices(
1528                                         struct btrfs_device_info *devices,
1529                                         size_t nr_devices)
1530 {
1531         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1532              btrfs_cmp_device_free_bytes, NULL);
1533 }
1534
1535 /*
1536  * The helper to calc the free space on the devices that can be used to store
1537  * file data.
1538  */
1539 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1540 {
1541         struct btrfs_fs_info *fs_info = root->fs_info;
1542         struct btrfs_device_info *devices_info;
1543         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1544         struct btrfs_device *device;
1545         u64 skip_space;
1546         u64 type;
1547         u64 avail_space;
1548         u64 used_space;
1549         u64 min_stripe_size;
1550         int min_stripes = 1, num_stripes = 1;
1551         int i = 0, nr_devices;
1552         int ret;
1553
1554         nr_devices = fs_info->fs_devices->open_devices;
1555         BUG_ON(!nr_devices);
1556
1557         devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1558                                GFP_NOFS);
1559         if (!devices_info)
1560                 return -ENOMEM;
1561
1562         /* calc min stripe number for data space alloction */
1563         type = btrfs_get_alloc_profile(root, 1);
1564         if (type & BTRFS_BLOCK_GROUP_RAID0) {
1565                 min_stripes = 2;
1566                 num_stripes = nr_devices;
1567         } else if (type & BTRFS_BLOCK_GROUP_RAID1) {
1568                 min_stripes = 2;
1569                 num_stripes = 2;
1570         } else if (type & BTRFS_BLOCK_GROUP_RAID10) {
1571                 min_stripes = 4;
1572                 num_stripes = 4;
1573         }
1574
1575         if (type & BTRFS_BLOCK_GROUP_DUP)
1576                 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1577         else
1578                 min_stripe_size = BTRFS_STRIPE_LEN;
1579
1580         list_for_each_entry(device, &fs_devices->devices, dev_list) {
1581                 if (!device->in_fs_metadata || !device->bdev ||
1582                     device->is_tgtdev_for_dev_replace)
1583                         continue;
1584
1585                 avail_space = device->total_bytes - device->bytes_used;
1586
1587                 /* align with stripe_len */
1588                 do_div(avail_space, BTRFS_STRIPE_LEN);
1589                 avail_space *= BTRFS_STRIPE_LEN;
1590
1591                 /*
1592                  * In order to avoid overwritting the superblock on the drive,
1593                  * btrfs starts at an offset of at least 1MB when doing chunk
1594                  * allocation.
1595                  */
1596                 skip_space = 1024 * 1024;
1597
1598                 /* user can set the offset in fs_info->alloc_start. */
1599                 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1600                     device->total_bytes)
1601                         skip_space = max(fs_info->alloc_start, skip_space);
1602
1603                 /*
1604                  * btrfs can not use the free space in [0, skip_space - 1],
1605                  * we must subtract it from the total. In order to implement
1606                  * it, we account the used space in this range first.
1607                  */
1608                 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1609                                                      &used_space);
1610                 if (ret) {
1611                         kfree(devices_info);
1612                         return ret;
1613                 }
1614
1615                 /* calc the free space in [0, skip_space - 1] */
1616                 skip_space -= used_space;
1617
1618                 /*
1619                  * we can use the free space in [0, skip_space - 1], subtract
1620                  * it from the total.
1621                  */
1622                 if (avail_space && avail_space >= skip_space)
1623                         avail_space -= skip_space;
1624                 else
1625                         avail_space = 0;
1626
1627                 if (avail_space < min_stripe_size)
1628                         continue;
1629
1630                 devices_info[i].dev = device;
1631                 devices_info[i].max_avail = avail_space;
1632
1633                 i++;
1634         }
1635
1636         nr_devices = i;
1637
1638         btrfs_descending_sort_devices(devices_info, nr_devices);
1639
1640         i = nr_devices - 1;
1641         avail_space = 0;
1642         while (nr_devices >= min_stripes) {
1643                 if (num_stripes > nr_devices)
1644                         num_stripes = nr_devices;
1645
1646                 if (devices_info[i].max_avail >= min_stripe_size) {
1647                         int j;
1648                         u64 alloc_size;
1649
1650                         avail_space += devices_info[i].max_avail * num_stripes;
1651                         alloc_size = devices_info[i].max_avail;
1652                         for (j = i + 1 - num_stripes; j <= i; j++)
1653                                 devices_info[j].max_avail -= alloc_size;
1654                 }
1655                 i--;
1656                 nr_devices--;
1657         }
1658
1659         kfree(devices_info);
1660         *free_bytes = avail_space;
1661         return 0;
1662 }
1663
1664 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1665 {
1666         struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1667         struct btrfs_super_block *disk_super = fs_info->super_copy;
1668         struct list_head *head = &fs_info->space_info;
1669         struct btrfs_space_info *found;
1670         u64 total_used = 0;
1671         u64 total_free_data = 0;
1672         int bits = dentry->d_sb->s_blocksize_bits;
1673         __be32 *fsid = (__be32 *)fs_info->fsid;
1674         int ret;
1675
1676         /* holding chunk_muext to avoid allocating new chunks */
1677         mutex_lock(&fs_info->chunk_mutex);
1678         rcu_read_lock();
1679         list_for_each_entry_rcu(found, head, list) {
1680                 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1681                         total_free_data += found->disk_total - found->disk_used;
1682                         total_free_data -=
1683                                 btrfs_account_ro_block_groups_free_space(found);
1684                 }
1685
1686                 total_used += found->disk_used;
1687         }
1688         rcu_read_unlock();
1689
1690         buf->f_namelen = BTRFS_NAME_LEN;
1691         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1692         buf->f_bfree = buf->f_blocks - (total_used >> bits);
1693         buf->f_bsize = dentry->d_sb->s_blocksize;
1694         buf->f_type = BTRFS_SUPER_MAGIC;
1695         buf->f_bavail = total_free_data;
1696         ret = btrfs_calc_avail_data_space(fs_info->tree_root, &total_free_data);
1697         if (ret) {
1698                 mutex_unlock(&fs_info->chunk_mutex);
1699                 return ret;
1700         }
1701         buf->f_bavail += total_free_data;
1702         buf->f_bavail = buf->f_bavail >> bits;
1703         mutex_unlock(&fs_info->chunk_mutex);
1704
1705         /* We treat it as constant endianness (it doesn't matter _which_)
1706            because we want the fsid to come out the same whether mounted
1707            on a big-endian or little-endian host */
1708         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1709         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1710         /* Mask in the root object ID too, to disambiguate subvols */
1711         buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1712         buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1713
1714         return 0;
1715 }
1716
1717 static void btrfs_kill_super(struct super_block *sb)
1718 {
1719         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1720         kill_anon_super(sb);
1721         free_fs_info(fs_info);
1722 }
1723
1724 static struct file_system_type btrfs_fs_type = {
1725         .owner          = THIS_MODULE,
1726         .name           = "btrfs",
1727         .mount          = btrfs_mount,
1728         .kill_sb        = btrfs_kill_super,
1729         .fs_flags       = FS_REQUIRES_DEV,
1730 };
1731 MODULE_ALIAS_FS("btrfs");
1732
1733 /*
1734  * used by btrfsctl to scan devices when no FS is mounted
1735  */
1736 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1737                                 unsigned long arg)
1738 {
1739         struct btrfs_ioctl_vol_args *vol;
1740         struct btrfs_fs_devices *fs_devices;
1741         int ret = -ENOTTY;
1742
1743         if (!capable(CAP_SYS_ADMIN))
1744                 return -EPERM;
1745
1746         vol = memdup_user((void __user *)arg, sizeof(*vol));
1747         if (IS_ERR(vol))
1748                 return PTR_ERR(vol);
1749
1750         switch (cmd) {
1751         case BTRFS_IOC_SCAN_DEV:
1752                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1753                                             &btrfs_fs_type, &fs_devices);
1754                 break;
1755         case BTRFS_IOC_DEVICES_READY:
1756                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1757                                             &btrfs_fs_type, &fs_devices);
1758                 if (ret)
1759                         break;
1760                 ret = !(fs_devices->num_devices == fs_devices->total_devices);
1761                 break;
1762         }
1763
1764         kfree(vol);
1765         return ret;
1766 }
1767
1768 static int btrfs_freeze(struct super_block *sb)
1769 {
1770         struct btrfs_trans_handle *trans;
1771         struct btrfs_root *root = btrfs_sb(sb)->tree_root;
1772
1773         trans = btrfs_attach_transaction_barrier(root);
1774         if (IS_ERR(trans)) {
1775                 /* no transaction, don't bother */
1776                 if (PTR_ERR(trans) == -ENOENT)
1777                         return 0;
1778                 return PTR_ERR(trans);
1779         }
1780         return btrfs_commit_transaction(trans, root);
1781 }
1782
1783 static int btrfs_unfreeze(struct super_block *sb)
1784 {
1785         return 0;
1786 }
1787
1788 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
1789 {
1790         struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
1791         struct btrfs_fs_devices *cur_devices;
1792         struct btrfs_device *dev, *first_dev = NULL;
1793         struct list_head *head;
1794         struct rcu_string *name;
1795
1796         mutex_lock(&fs_info->fs_devices->device_list_mutex);
1797         cur_devices = fs_info->fs_devices;
1798         while (cur_devices) {
1799                 head = &cur_devices->devices;
1800                 list_for_each_entry(dev, head, dev_list) {
1801                         if (dev->missing)
1802                                 continue;
1803                         if (!first_dev || dev->devid < first_dev->devid)
1804                                 first_dev = dev;
1805                 }
1806                 cur_devices = cur_devices->seed;
1807         }
1808
1809         if (first_dev) {
1810                 rcu_read_lock();
1811                 name = rcu_dereference(first_dev->name);
1812                 seq_escape(m, name->str, " \t\n\\");
1813                 rcu_read_unlock();
1814         } else {
1815                 WARN_ON(1);
1816         }
1817         mutex_unlock(&fs_info->fs_devices->device_list_mutex);
1818         return 0;
1819 }
1820
1821 static const struct super_operations btrfs_super_ops = {
1822         .drop_inode     = btrfs_drop_inode,
1823         .evict_inode    = btrfs_evict_inode,
1824         .put_super      = btrfs_put_super,
1825         .sync_fs        = btrfs_sync_fs,
1826         .show_options   = btrfs_show_options,
1827         .show_devname   = btrfs_show_devname,
1828         .write_inode    = btrfs_write_inode,
1829         .alloc_inode    = btrfs_alloc_inode,
1830         .destroy_inode  = btrfs_destroy_inode,
1831         .statfs         = btrfs_statfs,
1832         .remount_fs     = btrfs_remount,
1833         .freeze_fs      = btrfs_freeze,
1834         .unfreeze_fs    = btrfs_unfreeze,
1835 };
1836
1837 static const struct file_operations btrfs_ctl_fops = {
1838         .unlocked_ioctl  = btrfs_control_ioctl,
1839         .compat_ioctl = btrfs_control_ioctl,
1840         .owner   = THIS_MODULE,
1841         .llseek = noop_llseek,
1842 };
1843
1844 static struct miscdevice btrfs_misc = {
1845         .minor          = BTRFS_MINOR,
1846         .name           = "btrfs-control",
1847         .fops           = &btrfs_ctl_fops
1848 };
1849
1850 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1851 MODULE_ALIAS("devname:btrfs-control");
1852
1853 static int btrfs_interface_init(void)
1854 {
1855         return misc_register(&btrfs_misc);
1856 }
1857
1858 static void btrfs_interface_exit(void)
1859 {
1860         if (misc_deregister(&btrfs_misc) < 0)
1861                 printk(KERN_INFO "BTRFS: misc_deregister failed for control device\n");
1862 }
1863
1864 static void btrfs_print_info(void)
1865 {
1866         printk(KERN_INFO "Btrfs loaded"
1867 #ifdef CONFIG_BTRFS_DEBUG
1868                         ", debug=on"
1869 #endif
1870 #ifdef CONFIG_BTRFS_ASSERT
1871                         ", assert=on"
1872 #endif
1873 #ifdef CONFIG_BTRFS_FS_CHECK_INTEGRITY
1874                         ", integrity-checker=on"
1875 #endif
1876                         "\n");
1877 }
1878
1879 static int btrfs_run_sanity_tests(void)
1880 {
1881         int ret;
1882
1883         ret = btrfs_init_test_fs();
1884         if (ret)
1885                 return ret;
1886
1887         ret = btrfs_test_free_space_cache();
1888         if (ret)
1889                 goto out;
1890         ret = btrfs_test_extent_buffer_operations();
1891         if (ret)
1892                 goto out;
1893         ret = btrfs_test_extent_io();
1894         if (ret)
1895                 goto out;
1896         ret = btrfs_test_inodes();
1897 out:
1898         btrfs_destroy_test_fs();
1899         return ret;
1900 }
1901
1902 static int __init init_btrfs_fs(void)
1903 {
1904         int err;
1905
1906         err = btrfs_hash_init();
1907         if (err)
1908                 return err;
1909
1910         btrfs_props_init();
1911
1912         err = btrfs_init_sysfs();
1913         if (err)
1914                 goto free_hash;
1915
1916         btrfs_init_compress();
1917
1918         err = btrfs_init_cachep();
1919         if (err)
1920                 goto free_compress;
1921
1922         err = extent_io_init();
1923         if (err)
1924                 goto free_cachep;
1925
1926         err = extent_map_init();
1927         if (err)
1928                 goto free_extent_io;
1929
1930         err = ordered_data_init();
1931         if (err)
1932                 goto free_extent_map;
1933
1934         err = btrfs_delayed_inode_init();
1935         if (err)
1936                 goto free_ordered_data;
1937
1938         err = btrfs_auto_defrag_init();
1939         if (err)
1940                 goto free_delayed_inode;
1941
1942         err = btrfs_delayed_ref_init();
1943         if (err)
1944                 goto free_auto_defrag;
1945
1946         err = btrfs_prelim_ref_init();
1947         if (err)
1948                 goto free_prelim_ref;
1949
1950         err = btrfs_interface_init();
1951         if (err)
1952                 goto free_delayed_ref;
1953
1954         btrfs_init_lockdep();
1955
1956         btrfs_print_info();
1957
1958         err = btrfs_run_sanity_tests();
1959         if (err)
1960                 goto unregister_ioctl;
1961
1962         err = register_filesystem(&btrfs_fs_type);
1963         if (err)
1964                 goto unregister_ioctl;
1965
1966         return 0;
1967
1968 unregister_ioctl:
1969         btrfs_interface_exit();
1970 free_prelim_ref:
1971         btrfs_prelim_ref_exit();
1972 free_delayed_ref:
1973         btrfs_delayed_ref_exit();
1974 free_auto_defrag:
1975         btrfs_auto_defrag_exit();
1976 free_delayed_inode:
1977         btrfs_delayed_inode_exit();
1978 free_ordered_data:
1979         ordered_data_exit();
1980 free_extent_map:
1981         extent_map_exit();
1982 free_extent_io:
1983         extent_io_exit();
1984 free_cachep:
1985         btrfs_destroy_cachep();
1986 free_compress:
1987         btrfs_exit_compress();
1988         btrfs_exit_sysfs();
1989 free_hash:
1990         btrfs_hash_exit();
1991         return err;
1992 }
1993
1994 static void __exit exit_btrfs_fs(void)
1995 {
1996         btrfs_destroy_cachep();
1997         btrfs_delayed_ref_exit();
1998         btrfs_auto_defrag_exit();
1999         btrfs_delayed_inode_exit();
2000         btrfs_prelim_ref_exit();
2001         ordered_data_exit();
2002         extent_map_exit();
2003         extent_io_exit();
2004         btrfs_interface_exit();
2005         unregister_filesystem(&btrfs_fs_type);
2006         btrfs_exit_sysfs();
2007         btrfs_cleanup_fs_uuids();
2008         btrfs_exit_compress();
2009         btrfs_hash_exit();
2010 }
2011
2012 late_initcall(init_btrfs_fs);
2013 module_exit(exit_btrfs_fs)
2014
2015 MODULE_LICENSE("GPL");