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/mnt_namespace.h>
  44 #include "compat.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 "ioctl.h"
  51 #include "print-tree.h"
  52 #include "xattr.h"
  53 #include "volumes.h"
  54 #include "version.h"
  55 #include "export.h"
  56 #include "compression.h"
  57
  58 #define CREATE_TRACE_POINTS
  59 #include <trace/events/btrfs.h>
  60
  61 static const struct super_operations btrfs_super_ops;
  62 static struct file_system_type btrfs_fs_type;
  63
  64 static const char *btrfs_decode_error(struct btrfs_fs_info *fs_info, int errno,
  65                                       char nbuf[16])
  66 {
  67         char *errstr = NULL;
  68
  69         switch (errno) {
  70         case -EIO:
  71                 errstr = "IO failure";
  72                 break;
  73         case -ENOMEM:
  74                 errstr = "Out of memory";
  75                 break;
  76         case -EROFS:
  77                 errstr = "Readonly filesystem";
  78                 break;
  79         default:
  80                 if (nbuf) {
  81                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
  82                                 errstr = nbuf;
  83                 }
  84                 break;
  85         }
  86
  87         return errstr;
  88 }
  89
  90 static void __save_error_info(struct btrfs_fs_info *fs_info)
  91 {
  92         /*
  93          * today we only save the error info into ram.  Long term we'll
  94          * also send it down to the disk
  95          */
  96         fs_info->fs_state = BTRFS_SUPER_FLAG_ERROR;
  97 }
  98
  99 /* NOTE:
 100  *      We move write_super stuff at umount in order to avoid deadlock
 101  *      for umount hold all lock.
 102  */
 103 static void save_error_info(struct btrfs_fs_info *fs_info)
 104 {
 105         __save_error_info(fs_info);
 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 (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
 117                 sb->s_flags |= MS_RDONLY;
 118                 printk(KERN_INFO "btrfs is forced readonly\n");
 119         }
 120 }
 121
 122 /*
 123  * __btrfs_std_error decodes expected errors from the caller and
 124  * invokes the approciate error response.
 125  */
 126 void __btrfs_std_error(struct btrfs_fs_info *fs_info, const char *function,
 127                      unsigned int line, int errno)
 128 {
 129         struct super_block *sb = fs_info->sb;
 130         char nbuf[16];
 131         const char *errstr;
 132
 133         /*
 134          * Special case: if the error is EROFS, and we're already
 135          * under MS_RDONLY, then it is safe here.
 136          */
 137         if (errno == -EROFS && (sb->s_flags & MS_RDONLY))
 138                 return;
 139
 140         errstr = btrfs_decode_error(fs_info, errno, nbuf);
 141         printk(KERN_CRIT "BTRFS error (device %s) in %s:%d: %s\n",
 142                 sb->s_id, function, line, errstr);
 143         save_error_info(fs_info);
 144
 145         btrfs_handle_error(fs_info);
 146 }
 147
 148 static void btrfs_put_super(struct super_block *sb)
 149 {
 150         struct btrfs_root *root = btrfs_sb(sb);
 151         int ret;
 152
 153         ret = close_ctree(root);
 154         sb->s_fs_info = NULL;
 155
 156         (void)ret; /* FIXME: need to fix VFS to return error? */
 157 }
 158
 159 enum {
 160         Opt_degraded, Opt_subvol, Opt_subvolid, Opt_device, Opt_nodatasum,
 161         Opt_nodatacow, Opt_max_inline, Opt_alloc_start, Opt_nobarrier, Opt_ssd,
 162         Opt_nossd, Opt_ssd_spread, Opt_thread_pool, Opt_noacl, Opt_compress,
 163         Opt_compress_type, Opt_compress_force, Opt_compress_force_type,
 164         Opt_notreelog, Opt_ratio, Opt_flushoncommit, Opt_discard,
 165         Opt_space_cache, Opt_clear_cache, Opt_user_subvol_rm_allowed,
 166         Opt_enospc_debug, Opt_subvolrootid, Opt_defrag,
 167         Opt_inode_cache, Opt_err,
 168 };
 169
 170 static match_table_t tokens = {
 171         {Opt_degraded, "degraded"},
 172         {Opt_subvol, "subvol=%s"},
 173         {Opt_subvolid, "subvolid=%d"},
 174         {Opt_device, "device=%s"},
 175         {Opt_nodatasum, "nodatasum"},
 176         {Opt_nodatacow, "nodatacow"},
 177         {Opt_nobarrier, "nobarrier"},
 178         {Opt_max_inline, "max_inline=%s"},
 179         {Opt_alloc_start, "alloc_start=%s"},
 180         {Opt_thread_pool, "thread_pool=%d"},
 181         {Opt_compress, "compress"},
 182         {Opt_compress_type, "compress=%s"},
 183         {Opt_compress_force, "compress-force"},
 184         {Opt_compress_force_type, "compress-force=%s"},
 185         {Opt_ssd, "ssd"},
 186         {Opt_ssd_spread, "ssd_spread"},
 187         {Opt_nossd, "nossd"},
 188         {Opt_noacl, "noacl"},
 189         {Opt_notreelog, "notreelog"},
 190         {Opt_flushoncommit, "flushoncommit"},
 191         {Opt_ratio, "metadata_ratio=%d"},
 192         {Opt_discard, "discard"},
 193         {Opt_space_cache, "space_cache"},
 194         {Opt_clear_cache, "clear_cache"},
 195         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
 196         {Opt_enospc_debug, "enospc_debug"},
 197         {Opt_subvolrootid, "subvolrootid=%d"},
 198         {Opt_defrag, "autodefrag"},
 199         {Opt_inode_cache, "inode_cache"},
 200         {Opt_err, NULL},
 201 };
 202
 203 /*
 204  * Regular mount options parser.  Everything that is needed only when
 205  * reading in a new superblock is parsed here.
 206  */
 207 int btrfs_parse_options(struct btrfs_root *root, char *options)
 208 {
 209         struct btrfs_fs_info *info = root->fs_info;
 210         substring_t args[MAX_OPT_ARGS];
 211         char *p, *num, *orig;
 212         int intarg;
 213         int ret = 0;
 214         char *compress_type;
 215         bool compress_force = false;
 216
 217         if (!options)
 218                 return 0;
 219
 220         /*
 221          * strsep changes the string, duplicate it because parse_options
 222          * gets called twice
 223          */
 224         options = kstrdup(options, GFP_NOFS);
 225         if (!options)
 226                 return -ENOMEM;
 227
 228         orig = options;
 229
 230         while ((p = strsep(&options, ",")) != NULL) {
 231                 int token;
 232                 if (!*p)
 233                         continue;
 234
 235                 token = match_token(p, tokens, args);
 236                 switch (token) {
 237                 case Opt_degraded:
 238                         printk(KERN_INFO "btrfs: allowing degraded mounts\n");
 239                         btrfs_set_opt(info->mount_opt, DEGRADED);
 240                         break;
 241                 case Opt_subvol:
 242                 case Opt_subvolid:
 243                 case Opt_subvolrootid:
 244                 case Opt_device:
 245                         /*
 246                          * These are parsed by btrfs_parse_early_options
 247                          * and can be happily ignored here.
 248                          */
 249                         break;
 250                 case Opt_nodatasum:
 251                         printk(KERN_INFO "btrfs: setting nodatasum\n");
 252                         btrfs_set_opt(info->mount_opt, NODATASUM);
 253                         break;
 254                 case Opt_nodatacow:
 255                         printk(KERN_INFO "btrfs: setting nodatacow\n");
 256                         btrfs_set_opt(info->mount_opt, NODATACOW);
 257                         btrfs_set_opt(info->mount_opt, NODATASUM);
 258                         break;
 259                 case Opt_compress_force:
 260                 case Opt_compress_force_type:
 261                         compress_force = true;
 262                 case Opt_compress:
 263                 case Opt_compress_type:
 264                         if (token == Opt_compress ||
 265                             token == Opt_compress_force ||
 266                             strcmp(args[0].from, "zlib") == 0) {
 267                                 compress_type = "zlib";
 268                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
 269                         } else if (strcmp(args[0].from, "lzo") == 0) {
 270                                 compress_type = "lzo";
 271                                 info->compress_type = BTRFS_COMPRESS_LZO;
 272                         } else {
 273                                 ret = -EINVAL;
 274                                 goto out;
 275                         }
 276
 277                         btrfs_set_opt(info->mount_opt, COMPRESS);
 278                         if (compress_force) {
 279                                 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
 280                                 pr_info("btrfs: force %s compression\n",
 281                                         compress_type);
 282                         } else
 283                                 pr_info("btrfs: use %s compression\n",
 284                                         compress_type);
 285                         break;
 286                 case Opt_ssd:
 287                         printk(KERN_INFO "btrfs: use ssd allocation scheme\n");
 288                         btrfs_set_opt(info->mount_opt, SSD);
 289                         break;
 290                 case Opt_ssd_spread:
 291                         printk(KERN_INFO "btrfs: use spread ssd "
 292                                "allocation scheme\n");
 293                         btrfs_set_opt(info->mount_opt, SSD);
 294                         btrfs_set_opt(info->mount_opt, SSD_SPREAD);
 295                         break;
 296                 case Opt_nossd:
 297                         printk(KERN_INFO "btrfs: not using ssd allocation "
 298                                "scheme\n");
 299                         btrfs_set_opt(info->mount_opt, NOSSD);
 300                         btrfs_clear_opt(info->mount_opt, SSD);
 301                         btrfs_clear_opt(info->mount_opt, SSD_SPREAD);
 302                         break;
 303                 case Opt_nobarrier:
 304                         printk(KERN_INFO "btrfs: turning off barriers\n");
 305                         btrfs_set_opt(info->mount_opt, NOBARRIER);
 306                         break;
 307                 case Opt_thread_pool:
 308                         intarg = 0;
 309                         match_int(&args[0], &intarg);
 310                         if (intarg) {
 311                                 info->thread_pool_size = intarg;
 312                                 printk(KERN_INFO "btrfs: thread pool %d\n",
 313                                        info->thread_pool_size);
 314                         }
 315                         break;
 316                 case Opt_max_inline:
 317                         num = match_strdup(&args[0]);
 318                         if (num) {
 319                                 info->max_inline = memparse(num, NULL);
 320                                 kfree(num);
 321
 322                                 if (info->max_inline) {
 323                                         info->max_inline = max_t(u64,
 324                                                 info->max_inline,
 325                                                 root->sectorsize);
 326                                 }
 327                                 printk(KERN_INFO "btrfs: max_inline at %llu\n",
 328                                         (unsigned long long)info->max_inline);
 329                         }
 330                         break;
 331                 case Opt_alloc_start:
 332                         num = match_strdup(&args[0]);
 333                         if (num) {
 334                                 info->alloc_start = memparse(num, NULL);
 335                                 kfree(num);
 336                                 printk(KERN_INFO
 337                                         "btrfs: allocations start at %llu\n",
 338                                         (unsigned long long)info->alloc_start);
 339                         }
 340                         break;
 341                 case Opt_noacl:
 342                         root->fs_info->sb->s_flags &= ~MS_POSIXACL;
 343                         break;
 344                 case Opt_notreelog:
 345                         printk(KERN_INFO "btrfs: disabling tree log\n");
 346                         btrfs_set_opt(info->mount_opt, NOTREELOG);
 347                         break;
 348                 case Opt_flushoncommit:
 349                         printk(KERN_INFO "btrfs: turning on flush-on-commit\n");
 350                         btrfs_set_opt(info->mount_opt, FLUSHONCOMMIT);
 351                         break;
 352                 case Opt_ratio:
 353                         intarg = 0;
 354                         match_int(&args[0], &intarg);
 355                         if (intarg) {
 356                                 info->metadata_ratio = intarg;
 357                                 printk(KERN_INFO "btrfs: metadata ratio %d\n",
 358                                        info->metadata_ratio);
 359                         }
 360                         break;
 361                 case Opt_discard:
 362                         btrfs_set_opt(info->mount_opt, DISCARD);
 363                         break;
 364                 case Opt_space_cache:
 365                         printk(KERN_INFO "btrfs: enabling disk space caching\n");
 366                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 367                         break;
 368                 case Opt_inode_cache:
 369                         printk(KERN_INFO "btrfs: enabling inode map caching\n");
 370                         btrfs_set_opt(info->mount_opt, INODE_MAP_CACHE);
 371                         break;
 372                 case Opt_clear_cache:
 373                         printk(KERN_INFO "btrfs: force clearing of disk cache\n");
 374                         btrfs_set_opt(info->mount_opt, CLEAR_CACHE);
 375                         break;
 376                 case Opt_user_subvol_rm_allowed:
 377                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
 378                         break;
 379                 case Opt_enospc_debug:
 380                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
 381                         break;
 382                 case Opt_defrag:
 383                         printk(KERN_INFO "btrfs: enabling auto defrag");
 384                         btrfs_set_opt(info->mount_opt, AUTO_DEFRAG);
 385                         break;
 386                 case Opt_err:
 387                         printk(KERN_INFO "btrfs: unrecognized mount option "
 388                                "'%s'\n", p);
 389                         ret = -EINVAL;
 390                         goto out;
 391                 default:
 392                         break;
 393                 }
 394         }
 395 out:
 396         kfree(orig);
 397         return ret;
 398 }
 399
 400 /*
 401  * Parse mount options that are required early in the mount process.
 402  *
 403  * All other options will be parsed on much later in the mount process and
 404  * only when we need to allocate a new super block.
 405  */
 406 static int btrfs_parse_early_options(const char *options, fmode_t flags,
 407                 void *holder, char **subvol_name, u64 *subvol_objectid,
 408                 u64 *subvol_rootid, struct btrfs_fs_devices **fs_devices)
 409 {
 410         substring_t args[MAX_OPT_ARGS];
 411         char *opts, *orig, *p;
 412         int error = 0;
 413         int intarg;
 414
 415         if (!options)
 416                 return 0;
 417
 418         /*
 419          * strsep changes the string, duplicate it because parse_options
 420          * gets called twice
 421          */
 422         opts = kstrdup(options, GFP_KERNEL);
 423         if (!opts)
 424                 return -ENOMEM;
 425         orig = opts;
 426
 427         while ((p = strsep(&opts, ",")) != NULL) {
 428                 int token;
 429                 if (!*p)
 430                         continue;
 431
 432                 token = match_token(p, tokens, args);
 433                 switch (token) {
 434                 case Opt_subvol:
 435                         *subvol_name = match_strdup(&args[0]);
 436                         break;
 437                 case Opt_subvolid:
 438                         intarg = 0;
 439                         error = match_int(&args[0], &intarg);
 440                         if (!error) {
 441                                 /* we want the original fs_tree */
 442                                 if (!intarg)
 443                                         *subvol_objectid =
 444                                                 BTRFS_FS_TREE_OBJECTID;
 445                                 else
 446                                         *subvol_objectid = intarg;
 447                         }
 448                         break;
 449                 case Opt_subvolrootid:
 450                         intarg = 0;
 451                         error = match_int(&args[0], &intarg);
 452                         if (!error) {
 453                                 /* we want the original fs_tree */
 454                                 if (!intarg)
 455                                         *subvol_rootid =
 456                                                 BTRFS_FS_TREE_OBJECTID;
 457                                 else
 458                                         *subvol_rootid = intarg;
 459                         }
 460                         break;
 461                 case Opt_device:
 462                         error = btrfs_scan_one_device(match_strdup(&args[0]),
 463                                         flags, holder, fs_devices);
 464                         if (error)
 465                                 goto out;
 466                         break;
 467                 default:
 468                         break;
 469                 }
 470         }
 471
 472 out:
 473         kfree(orig);
 474         return error;
 475 }
 476
 477 static struct dentry *get_default_root(struct super_block *sb,
 478                                        u64 subvol_objectid)
 479 {
 480         struct btrfs_root *root = sb->s_fs_info;
 481         struct btrfs_root *new_root;
 482         struct btrfs_dir_item *di;
 483         struct btrfs_path *path;
 484         struct btrfs_key location;
 485         struct inode *inode;
 486         u64 dir_id;
 487         int new = 0;
 488
 489         /*
 490          * We have a specific subvol we want to mount, just setup location and
 491          * go look up the root.
 492          */
 493         if (subvol_objectid) {
 494                 location.objectid = subvol_objectid;
 495                 location.type = BTRFS_ROOT_ITEM_KEY;
 496                 location.offset = (u64)-1;
 497                 goto find_root;
 498         }
 499
 500         path = btrfs_alloc_path();
 501         if (!path)
 502                 return ERR_PTR(-ENOMEM);
 503         path->leave_spinning = 1;
 504
 505         /*
 506          * Find the "default" dir item which points to the root item that we
 507          * will mount by default if we haven't been given a specific subvolume
 508          * to mount.
 509          */
 510         dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
 511         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, "default", 7, 0);
 512         if (IS_ERR(di)) {
 513                 btrfs_free_path(path);
 514                 return ERR_CAST(di);
 515         }
 516         if (!di) {
 517                 /*
 518                  * Ok the default dir item isn't there.  This is weird since
 519                  * it's always been there, but don't freak out, just try and
 520                  * mount to root most subvolume.
 521                  */
 522                 btrfs_free_path(path);
 523                 dir_id = BTRFS_FIRST_FREE_OBJECTID;
 524                 new_root = root->fs_info->fs_root;
 525                 goto setup_root;
 526         }
 527
 528         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
 529         btrfs_free_path(path);
 530
 531 find_root:
 532         new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
 533         if (IS_ERR(new_root))
 534                 return ERR_CAST(new_root);
 535
 536         if (btrfs_root_refs(&new_root->root_item) == 0)
 537                 return ERR_PTR(-ENOENT);
 538
 539         dir_id = btrfs_root_dirid(&new_root->root_item);
 540 setup_root:
 541         location.objectid = dir_id;
 542         location.type = BTRFS_INODE_ITEM_KEY;
 543         location.offset = 0;
 544
 545         inode = btrfs_iget(sb, &location, new_root, &new);
 546         if (IS_ERR(inode))
 547                 return ERR_CAST(inode);
 548
 549         /*
 550          * If we're just mounting the root most subvol put the inode and return
 551          * a reference to the dentry.  We will have already gotten a reference
 552          * to the inode in btrfs_fill_super so we're good to go.
 553          */
 554         if (!new && sb->s_root->d_inode == inode) {
 555                 iput(inode);
 556                 return dget(sb->s_root);
 557         }
 558
 559         return d_obtain_alias(inode);
 560 }
 561
 562 static int btrfs_fill_super(struct super_block *sb,
 563                             struct btrfs_fs_devices *fs_devices,
 564                             void *data, int silent)
 565 {
 566         struct inode *inode;
 567         struct dentry *root_dentry;
 568         struct btrfs_root *tree_root;
 569         struct btrfs_key key;
 570         int err;
 571
 572         sb->s_maxbytes = MAX_LFS_FILESIZE;
 573         sb->s_magic = BTRFS_SUPER_MAGIC;
 574         sb->s_op = &btrfs_super_ops;
 575         sb->s_d_op = &btrfs_dentry_operations;
 576         sb->s_export_op = &btrfs_export_ops;
 577         sb->s_xattr = btrfs_xattr_handlers;
 578         sb->s_time_gran = 1;
 579 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 580         sb->s_flags |= MS_POSIXACL;
 581 #endif
 582
 583         tree_root = open_ctree(sb, fs_devices, (char *)data);
 584
 585         if (IS_ERR(tree_root)) {
 586                 printk("btrfs: open_ctree failed\n");
 587                 return PTR_ERR(tree_root);
 588         }
 589         sb->s_fs_info = tree_root;
 590
 591         key.objectid = BTRFS_FIRST_FREE_OBJECTID;
 592         key.type = BTRFS_INODE_ITEM_KEY;
 593         key.offset = 0;
 594         inode = btrfs_iget(sb, &key, tree_root->fs_info->fs_root, NULL);
 595         if (IS_ERR(inode)) {
 596                 err = PTR_ERR(inode);
 597                 goto fail_close;
 598         }
 599
 600         root_dentry = d_alloc_root(inode);
 601         if (!root_dentry) {
 602                 iput(inode);
 603                 err = -ENOMEM;
 604                 goto fail_close;
 605         }
 606
 607         sb->s_root = root_dentry;
 608
 609         save_mount_options(sb, data);
 610         cleancache_init_fs(sb);
 611         return 0;
 612
 613 fail_close:
 614         close_ctree(tree_root);
 615         return err;
 616 }
 617
 618 int btrfs_sync_fs(struct super_block *sb, int wait)
 619 {
 620         struct btrfs_trans_handle *trans;
 621         struct btrfs_root *root = btrfs_sb(sb);
 622         int ret;
 623
 624         trace_btrfs_sync_fs(wait);
 625
 626         if (!wait) {
 627                 filemap_flush(root->fs_info->btree_inode->i_mapping);
 628                 return 0;
 629         }
 630
 631         btrfs_start_delalloc_inodes(root, 0);
 632         btrfs_wait_ordered_extents(root, 0, 0);
 633
 634         trans = btrfs_start_transaction(root, 0);
 635         if (IS_ERR(trans))
 636                 return PTR_ERR(trans);
 637         ret = btrfs_commit_transaction(trans, root);
 638         return ret;
 639 }
 640
 641 static int btrfs_show_options(struct seq_file *seq, struct vfsmount *vfs)
 642 {
 643         struct btrfs_root *root = btrfs_sb(vfs->mnt_sb);
 644         struct btrfs_fs_info *info = root->fs_info;
 645         char *compress_type;
 646
 647         if (btrfs_test_opt(root, DEGRADED))
 648                 seq_puts(seq, ",degraded");
 649         if (btrfs_test_opt(root, NODATASUM))
 650                 seq_puts(seq, ",nodatasum");
 651         if (btrfs_test_opt(root, NODATACOW))
 652                 seq_puts(seq, ",nodatacow");
 653         if (btrfs_test_opt(root, NOBARRIER))
 654                 seq_puts(seq, ",nobarrier");
 655         if (info->max_inline != 8192 * 1024)
 656                 seq_printf(seq, ",max_inline=%llu",
 657                            (unsigned long long)info->max_inline);
 658         if (info->alloc_start != 0)
 659                 seq_printf(seq, ",alloc_start=%llu",
 660                            (unsigned long long)info->alloc_start);
 661         if (info->thread_pool_size !=  min_t(unsigned long,
 662                                              num_online_cpus() + 2, 8))
 663                 seq_printf(seq, ",thread_pool=%d", info->thread_pool_size);
 664         if (btrfs_test_opt(root, COMPRESS)) {
 665                 if (info->compress_type == BTRFS_COMPRESS_ZLIB)
 666                         compress_type = "zlib";
 667                 else
 668                         compress_type = "lzo";
 669                 if (btrfs_test_opt(root, FORCE_COMPRESS))
 670                         seq_printf(seq, ",compress-force=%s", compress_type);
 671                 else
 672                         seq_printf(seq, ",compress=%s", compress_type);
 673         }
 674         if (btrfs_test_opt(root, NOSSD))
 675                 seq_puts(seq, ",nossd");
 676         if (btrfs_test_opt(root, SSD_SPREAD))
 677                 seq_puts(seq, ",ssd_spread");
 678         else if (btrfs_test_opt(root, SSD))
 679                 seq_puts(seq, ",ssd");
 680         if (btrfs_test_opt(root, NOTREELOG))
 681                 seq_puts(seq, ",notreelog");
 682         if (btrfs_test_opt(root, FLUSHONCOMMIT))
 683                 seq_puts(seq, ",flushoncommit");
 684         if (btrfs_test_opt(root, DISCARD))
 685                 seq_puts(seq, ",discard");
 686         if (!(root->fs_info->sb->s_flags & MS_POSIXACL))
 687                 seq_puts(seq, ",noacl");
 688         if (btrfs_test_opt(root, SPACE_CACHE))
 689                 seq_puts(seq, ",space_cache");
 690         if (btrfs_test_opt(root, CLEAR_CACHE))
 691                 seq_puts(seq, ",clear_cache");
 692         if (btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
 693                 seq_puts(seq, ",user_subvol_rm_allowed");
 694         if (btrfs_test_opt(root, ENOSPC_DEBUG))
 695                 seq_puts(seq, ",enospc_debug");
 696         if (btrfs_test_opt(root, AUTO_DEFRAG))
 697                 seq_puts(seq, ",autodefrag");
 698         if (btrfs_test_opt(root, INODE_MAP_CACHE))
 699                 seq_puts(seq, ",inode_cache");
 700         return 0;
 701 }
 702
 703 static int btrfs_test_super(struct super_block *s, void *data)
 704 {
 705         struct btrfs_root *test_root = data;
 706         struct btrfs_root *root = btrfs_sb(s);
 707
 708         /*
 709          * If this super block is going away, return false as it
 710          * can't match as an existing super block.
 711          */
 712         if (!atomic_read(&s->s_active))
 713                 return 0;
 714         return root->fs_info->fs_devices == test_root->fs_info->fs_devices;
 715 }
 716
 717 static int btrfs_set_super(struct super_block *s, void *data)
 718 {
 719         s->s_fs_info = data;
 720
 721         return set_anon_super(s, data);
 722 }
 723
 724 /*
 725  * This will strip out the subvol=%s argument for an argument string and add
 726  * subvolid=0 to make sure we get the actual tree root for path walking to the
 727  * subvol we want.
 728  */
 729 static char *setup_root_args(char *args)
 730 {
 731         unsigned copied = 0;
 732         unsigned len = strlen(args) + 2;
 733         char *pos;
 734         char *ret;
 735
 736         /*
 737          * We need the same args as before, but minus
 738          *
 739          * subvol=a
 740          *
 741          * and add
 742          *
 743          * subvolid=0
 744          *
 745          * which is a difference of 2 characters, so we allocate strlen(args) +
 746          * 2 characters.
 747          */
 748         ret = kzalloc(len * sizeof(char), GFP_NOFS);
 749         if (!ret)
 750                 return NULL;
 751         pos = strstr(args, "subvol=");
 752
 753         /* This shouldn't happen, but just in case.. */
 754         if (!pos) {
 755                 kfree(ret);
 756                 return NULL;
 757         }
 758
 759         /*
 760          * The subvol=<> arg is not at the front of the string, copy everybody
 761          * up to that into ret.
 762          */
 763         if (pos != args) {
 764                 *pos = '\0';
 765                 strcpy(ret, args);
 766                 copied += strlen(args);
 767                 pos++;
 768         }
 769
 770         strncpy(ret + copied, "subvolid=0", len - copied);
 771
 772         /* Length of subvolid=0 */
 773         copied += 10;
 774
 775         /*
 776          * If there is no , after the subvol= option then we know there's no
 777          * other options and we can just return.
 778          */
 779         pos = strchr(pos, ',');
 780         if (!pos)
 781                 return ret;
 782
 783         /* Copy the rest of the arguments into our buffer */
 784         strncpy(ret + copied, pos, len - copied);
 785         copied += strlen(pos);
 786
 787         return ret;
 788 }
 789
 790 static struct dentry *mount_subvol(const char *subvol_name, int flags,
 791                                    const char *device_name, char *data)
 792 {
 793         struct super_block *s;
 794         struct dentry *root;
 795         struct vfsmount *mnt;
 796         struct mnt_namespace *ns_private;
 797         char *newargs;
 798         struct path path;
 799         int error;
 800
 801         newargs = setup_root_args(data);
 802         if (!newargs)
 803                 return ERR_PTR(-ENOMEM);
 804         mnt = vfs_kern_mount(&btrfs_fs_type, flags, device_name,
 805                              newargs);
 806         kfree(newargs);
 807         if (IS_ERR(mnt))
 808                 return ERR_CAST(mnt);
 809
 810         ns_private = create_mnt_ns(mnt);
 811         if (IS_ERR(ns_private)) {
 812                 mntput(mnt);
 813                 return ERR_CAST(ns_private);
 814         }
 815
 816         /*
 817          * This will trigger the automount of the subvol so we can just
 818          * drop the mnt we have here and return the dentry that we
 819          * found.
 820          */
 821         error = vfs_path_lookup(mnt->mnt_root, mnt, subvol_name,
 822                                 LOOKUP_FOLLOW, &path);
 823         put_mnt_ns(ns_private);
 824         if (error)
 825                 return ERR_PTR(error);
 826
 827         /* Get a ref to the sb and the dentry we found and return it */
 828         s = path.mnt->mnt_sb;
 829         atomic_inc(&s->s_active);
 830         root = dget(path.dentry);
 831         path_put(&path);
 832         down_write(&s->s_umount);
 833
 834         return root;
 835 }
 836
 837 /*
 838  * Find a superblock for the given device / mount point.
 839  *
 840  * Note:  This is based on get_sb_bdev from fs/super.c with a few additions
 841  *        for multiple device setup.  Make sure to keep it in sync.
 842  */
 843 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
 844                 const char *device_name, void *data)
 845 {
 846         struct block_device *bdev = NULL;
 847         struct super_block *s;
 848         struct dentry *root;
 849         struct btrfs_fs_devices *fs_devices = NULL;
 850         struct btrfs_root *tree_root = NULL;
 851         struct btrfs_fs_info *fs_info = NULL;
 852         fmode_t mode = FMODE_READ;
 853         char *subvol_name = NULL;
 854         u64 subvol_objectid = 0;
 855         u64 subvol_rootid = 0;
 856         int error = 0;
 857
 858         if (!(flags & MS_RDONLY))
 859                 mode |= FMODE_WRITE;
 860
 861         error = btrfs_parse_early_options(data, mode, fs_type,
 862                                           &subvol_name, &subvol_objectid,
 863                                           &subvol_rootid, &fs_devices);
 864         if (error)
 865                 return ERR_PTR(error);
 866
 867         if (subvol_name) {
 868                 root = mount_subvol(subvol_name, flags, device_name, data);
 869                 kfree(subvol_name);
 870                 return root;
 871         }
 872
 873         error = btrfs_scan_one_device(device_name, mode, fs_type, &fs_devices);
 874         if (error)
 875                 return ERR_PTR(error);
 876
 877         error = btrfs_open_devices(fs_devices, mode, fs_type);
 878         if (error)
 879                 return ERR_PTR(error);
 880
 881         if (!(flags & MS_RDONLY) && fs_devices->rw_devices == 0) {
 882                 error = -EACCES;
 883                 goto error_close_devices;
 884         }
 885
 886         /*
 887          * Setup a dummy root and fs_info for test/set super.  This is because
 888          * we don't actually fill this stuff out until open_ctree, but we need
 889          * it for searching for existing supers, so this lets us do that and
 890          * then open_ctree will properly initialize everything later.
 891          */
 892         fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
 893         tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
 894         if (!fs_info || !tree_root) {
 895                 error = -ENOMEM;
 896                 goto error_close_devices;
 897         }
 898         fs_info->tree_root = tree_root;
 899         fs_info->fs_devices = fs_devices;
 900         tree_root->fs_info = fs_info;
 901
 902         bdev = fs_devices->latest_bdev;
 903         s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
 904         if (IS_ERR(s)) {
 905                 error = PTR_ERR(s);
 906                 goto error_close_devices;
 907         }
 908
 909         if (s->s_root) {
 910                 if ((flags ^ s->s_flags) & MS_RDONLY) {
 911                         deactivate_locked_super(s);
 912                         return ERR_PTR(-EBUSY);
 913                 }
 914
 915                 btrfs_close_devices(fs_devices);
 916                 kfree(fs_info);
 917                 kfree(tree_root);
 918         } else {
 919                 char b[BDEVNAME_SIZE];
 920
 921                 s->s_flags = flags | MS_NOSEC;
 922                 strlcpy(s->s_id, bdevname(bdev, b), sizeof(s->s_id));
 923                 error = btrfs_fill_super(s, fs_devices, data,
 924                                          flags & MS_SILENT ? 1 : 0);
 925                 if (error) {
 926                         deactivate_locked_super(s);
 927                         return ERR_PTR(error);
 928                 }
 929
 930                 btrfs_sb(s)->fs_info->bdev_holder = fs_type;
 931                 s->s_flags |= MS_ACTIVE;
 932         }
 933
 934         root = get_default_root(s, subvol_objectid);
 935         if (IS_ERR(root)) {
 936                 deactivate_locked_super(s);
 937                 return root;
 938         }
 939
 940         return root;
 941
 942 error_close_devices:
 943         btrfs_close_devices(fs_devices);
 944         kfree(fs_info);
 945         kfree(tree_root);
 946         return ERR_PTR(error);
 947 }
 948
 949 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 950 {
 951         struct btrfs_root *root = btrfs_sb(sb);
 952         int ret;
 953
 954         ret = btrfs_parse_options(root, data);
 955         if (ret)
 956                 return -EINVAL;
 957
 958         if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
 959                 return 0;
 960
 961         if (*flags & MS_RDONLY) {
 962                 sb->s_flags |= MS_RDONLY;
 963
 964                 ret =  btrfs_commit_super(root);
 965                 WARN_ON(ret);
 966         } else {
 967                 if (root->fs_info->fs_devices->rw_devices == 0)
 968                         return -EACCES;
 969
 970                 if (btrfs_super_log_root(&root->fs_info->super_copy) != 0)
 971                         return -EINVAL;
 972
 973                 ret = btrfs_cleanup_fs_roots(root->fs_info);
 974                 WARN_ON(ret);
 975
 976                 /* recover relocation */
 977                 ret = btrfs_recover_relocation(root);
 978                 WARN_ON(ret);
 979
 980                 sb->s_flags &= ~MS_RDONLY;
 981         }
 982
 983         return 0;
 984 }
 985
 986 /* Used to sort the devices by max_avail(descending sort) */
 987 static int btrfs_cmp_device_free_bytes(const void *dev_info1,
 988                                        const void *dev_info2)
 989 {
 990         if (((struct btrfs_device_info *)dev_info1)->max_avail >
 991             ((struct btrfs_device_info *)dev_info2)->max_avail)
 992                 return -1;
 993         else if (((struct btrfs_device_info *)dev_info1)->max_avail <
 994                  ((struct btrfs_device_info *)dev_info2)->max_avail)
 995                 return 1;
 996         else
 997         return 0;
 998 }
 999
1000 /*
1001  * sort the devices by max_avail, in which max free extent size of each device
1002  * is stored.(Descending Sort)
1003  */
1004 static inline void btrfs_descending_sort_devices(
1005                                         struct btrfs_device_info *devices,
1006                                         size_t nr_devices)
1007 {
1008         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1009              btrfs_cmp_device_free_bytes, NULL);
1010 }
1011
1012 /*
1013  * The helper to calc the free space on the devices that can be used to store
1014  * file data.
1015  */
1016 static int btrfs_calc_avail_data_space(struct btrfs_root *root, u64 *free_bytes)
1017 {
1018         struct btrfs_fs_info *fs_info = root->fs_info;
1019         struct btrfs_device_info *devices_info;
1020         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1021         struct btrfs_device *device;
1022         u64 skip_space;
1023         u64 type;
1024         u64 avail_space;
1025         u64 used_space;
1026         u64 min_stripe_size;
1027         int min_stripes = 1;
1028         int i = 0, nr_devices;
1029         int ret;
1030
1031         nr_devices = fs_info->fs_devices->rw_devices;
1032         BUG_ON(!nr_devices);
1033
1034         devices_info = kmalloc(sizeof(*devices_info) * nr_devices,
1035                                GFP_NOFS);
1036         if (!devices_info)
1037                 return -ENOMEM;
1038
1039         /* calc min stripe number for data space alloction */
1040         type = btrfs_get_alloc_profile(root, 1);
1041         if (type & BTRFS_BLOCK_GROUP_RAID0)
1042                 min_stripes = 2;
1043         else if (type & BTRFS_BLOCK_GROUP_RAID1)
1044                 min_stripes = 2;
1045         else if (type & BTRFS_BLOCK_GROUP_RAID10)
1046                 min_stripes = 4;
1047
1048         if (type & BTRFS_BLOCK_GROUP_DUP)
1049                 min_stripe_size = 2 * BTRFS_STRIPE_LEN;
1050         else
1051                 min_stripe_size = BTRFS_STRIPE_LEN;
1052
1053         list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
1054                 if (!device->in_fs_metadata)
1055                         continue;
1056
1057                 avail_space = device->total_bytes - device->bytes_used;
1058
1059                 /* align with stripe_len */
1060                 do_div(avail_space, BTRFS_STRIPE_LEN);
1061                 avail_space *= BTRFS_STRIPE_LEN;
1062
1063                 /*
1064                  * In order to avoid overwritting the superblock on the drive,
1065                  * btrfs starts at an offset of at least 1MB when doing chunk
1066                  * allocation.
1067                  */
1068                 skip_space = 1024 * 1024;
1069
1070                 /* user can set the offset in fs_info->alloc_start. */
1071                 if (fs_info->alloc_start + BTRFS_STRIPE_LEN <=
1072                     device->total_bytes)
1073                         skip_space = max(fs_info->alloc_start, skip_space);
1074
1075                 /*
1076                  * btrfs can not use the free space in [0, skip_space - 1],
1077                  * we must subtract it from the total. In order to implement
1078                  * it, we account the used space in this range first.
1079                  */
1080                 ret = btrfs_account_dev_extents_size(device, 0, skip_space - 1,
1081                                                      &used_space);
1082                 if (ret) {
1083                         kfree(devices_info);
1084                         return ret;
1085                 }
1086
1087                 /* calc the free space in [0, skip_space - 1] */
1088                 skip_space -= used_space;
1089
1090                 /*
1091                  * we can use the free space in [0, skip_space - 1], subtract
1092                  * it from the total.
1093                  */
1094                 if (avail_space && avail_space >= skip_space)
1095                         avail_space -= skip_space;
1096                 else
1097                         avail_space = 0;
1098
1099                 if (avail_space < min_stripe_size)
1100                         continue;
1101
1102                 devices_info[i].dev = device;
1103                 devices_info[i].max_avail = avail_space;
1104
1105                 i++;
1106         }
1107
1108         nr_devices = i;
1109
1110         btrfs_descending_sort_devices(devices_info, nr_devices);
1111
1112         i = nr_devices - 1;
1113         avail_space = 0;
1114         while (nr_devices >= min_stripes) {
1115                 if (devices_info[i].max_avail >= min_stripe_size) {
1116                         int j;
1117                         u64 alloc_size;
1118
1119                         avail_space += devices_info[i].max_avail * min_stripes;
1120                         alloc_size = devices_info[i].max_avail;
1121                         for (j = i + 1 - min_stripes; j <= i; j++)
1122                                 devices_info[j].max_avail -= alloc_size;
1123                 }
1124                 i--;
1125                 nr_devices--;
1126         }
1127
1128         kfree(devices_info);
1129         *free_bytes = avail_space;
1130         return 0;
1131 }
1132
1133 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1134 {
1135         struct btrfs_root *root = btrfs_sb(dentry->d_sb);
1136         struct btrfs_super_block *disk_super = &root->fs_info->super_copy;
1137         struct list_head *head = &root->fs_info->space_info;
1138         struct btrfs_space_info *found;
1139         u64 total_used = 0;
1140         u64 total_free_data = 0;
1141         int bits = dentry->d_sb->s_blocksize_bits;
1142         __be32 *fsid = (__be32 *)root->fs_info->fsid;
1143         int ret;
1144
1145         /* holding chunk_muext to avoid allocating new chunks */
1146         mutex_lock(&root->fs_info->chunk_mutex);
1147         rcu_read_lock();
1148         list_for_each_entry_rcu(found, head, list) {
1149                 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
1150                         total_free_data += found->disk_total - found->disk_used;
1151                         total_free_data -=
1152                                 btrfs_account_ro_block_groups_free_space(found);
1153                 }
1154
1155                 total_used += found->disk_used;
1156         }
1157         rcu_read_unlock();
1158
1159         buf->f_namelen = BTRFS_NAME_LEN;
1160         buf->f_blocks = btrfs_super_total_bytes(disk_super) >> bits;
1161         buf->f_bfree = buf->f_blocks - (total_used >> bits);
1162         buf->f_bsize = dentry->d_sb->s_blocksize;
1163         buf->f_type = BTRFS_SUPER_MAGIC;
1164         buf->f_bavail = total_free_data;
1165         ret = btrfs_calc_avail_data_space(root, &total_free_data);
1166         if (ret) {
1167                 mutex_unlock(&root->fs_info->chunk_mutex);
1168                 return ret;
1169         }
1170         buf->f_bavail += total_free_data;
1171         buf->f_bavail = buf->f_bavail >> bits;
1172         mutex_unlock(&root->fs_info->chunk_mutex);
1173
1174         /* We treat it as constant endianness (it doesn't matter _which_)
1175            because we want the fsid to come out the same whether mounted
1176            on a big-endian or little-endian host */
1177         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
1178         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
1179         /* Mask in the root object ID too, to disambiguate subvols */
1180         buf->f_fsid.val[0] ^= BTRFS_I(dentry->d_inode)->root->objectid >> 32;
1181         buf->f_fsid.val[1] ^= BTRFS_I(dentry->d_inode)->root->objectid;
1182
1183         return 0;
1184 }
1185
1186 static struct file_system_type btrfs_fs_type = {
1187         .owner          = THIS_MODULE,
1188         .name           = "btrfs",
1189         .mount          = btrfs_mount,
1190         .kill_sb        = kill_anon_super,
1191         .fs_flags       = FS_REQUIRES_DEV,
1192 };
1193
1194 /*
1195  * used by btrfsctl to scan devices when no FS is mounted
1196  */
1197 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
1198                                 unsigned long arg)
1199 {
1200         struct btrfs_ioctl_vol_args *vol;
1201         struct btrfs_fs_devices *fs_devices;
1202         int ret = -ENOTTY;
1203
1204         if (!capable(CAP_SYS_ADMIN))
1205                 return -EPERM;
1206
1207         vol = memdup_user((void __user *)arg, sizeof(*vol));
1208         if (IS_ERR(vol))
1209                 return PTR_ERR(vol);
1210
1211         switch (cmd) {
1212         case BTRFS_IOC_SCAN_DEV:
1213                 ret = btrfs_scan_one_device(vol->name, FMODE_READ,
1214                                             &btrfs_fs_type, &fs_devices);
1215                 break;
1216         }
1217
1218         kfree(vol);
1219         return ret;
1220 }
1221
1222 static int btrfs_freeze(struct super_block *sb)
1223 {
1224         struct btrfs_root *root = btrfs_sb(sb);
1225         mutex_lock(&root->fs_info->transaction_kthread_mutex);
1226         mutex_lock(&root->fs_info->cleaner_mutex);
1227         return 0;
1228 }
1229
1230 static int btrfs_unfreeze(struct super_block *sb)
1231 {
1232         struct btrfs_root *root = btrfs_sb(sb);
1233         mutex_unlock(&root->fs_info->cleaner_mutex);
1234         mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1235         return 0;
1236 }
1237
1238 static const struct super_operations btrfs_super_ops = {
1239         .drop_inode     = btrfs_drop_inode,
1240         .evict_inode    = btrfs_evict_inode,
1241         .put_super      = btrfs_put_super,
1242         .sync_fs        = btrfs_sync_fs,
1243         .show_options   = btrfs_show_options,
1244         .write_inode    = btrfs_write_inode,
1245         .dirty_inode    = btrfs_dirty_inode,
1246         .alloc_inode    = btrfs_alloc_inode,
1247         .destroy_inode  = btrfs_destroy_inode,
1248         .statfs         = btrfs_statfs,
1249         .remount_fs     = btrfs_remount,
1250         .freeze_fs      = btrfs_freeze,
1251         .unfreeze_fs    = btrfs_unfreeze,
1252 };
1253
1254 static const struct file_operations btrfs_ctl_fops = {
1255         .unlocked_ioctl  = btrfs_control_ioctl,
1256         .compat_ioctl = btrfs_control_ioctl,
1257         .owner   = THIS_MODULE,
1258         .llseek = noop_llseek,
1259 };
1260
1261 static struct miscdevice btrfs_misc = {
1262         .minor          = BTRFS_MINOR,
1263         .name           = "btrfs-control",
1264         .fops           = &btrfs_ctl_fops
1265 };
1266
1267 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
1268 MODULE_ALIAS("devname:btrfs-control");
1269
1270 static int btrfs_interface_init(void)
1271 {
1272         return misc_register(&btrfs_misc);
1273 }
1274
1275 static void btrfs_interface_exit(void)
1276 {
1277         if (misc_deregister(&btrfs_misc) < 0)
1278                 printk(KERN_INFO "misc_deregister failed for control device");
1279 }
1280
1281 static int __init init_btrfs_fs(void)
1282 {
1283         int err;
1284
1285         err = btrfs_init_sysfs();
1286         if (err)
1287                 return err;
1288
1289         err = btrfs_init_compress();
1290         if (err)
1291                 goto free_sysfs;
1292
1293         err = btrfs_init_cachep();
1294         if (err)
1295                 goto free_compress;
1296
1297         err = extent_io_init();
1298         if (err)
1299                 goto free_cachep;
1300
1301         err = extent_map_init();
1302         if (err)
1303                 goto free_extent_io;
1304
1305         err = btrfs_delayed_inode_init();
1306         if (err)
1307                 goto free_extent_map;
1308
1309         err = btrfs_interface_init();
1310         if (err)
1311                 goto free_delayed_inode;
1312
1313         err = register_filesystem(&btrfs_fs_type);
1314         if (err)
1315                 goto unregister_ioctl;
1316
1317         printk(KERN_INFO "%s loaded\n", BTRFS_BUILD_VERSION);
1318         return 0;
1319
1320 unregister_ioctl:
1321         btrfs_interface_exit();
1322 free_delayed_inode:
1323         btrfs_delayed_inode_exit();
1324 free_extent_map:
1325         extent_map_exit();
1326 free_extent_io:
1327         extent_io_exit();
1328 free_cachep:
1329         btrfs_destroy_cachep();
1330 free_compress:
1331         btrfs_exit_compress();
1332 free_sysfs:
1333         btrfs_exit_sysfs();
1334         return err;
1335 }
1336
1337 static void __exit exit_btrfs_fs(void)
1338 {
1339         btrfs_destroy_cachep();
1340         btrfs_delayed_inode_exit();
1341         extent_map_exit();
1342         extent_io_exit();
1343         btrfs_interface_exit();
1344         unregister_filesystem(&btrfs_fs_type);
1345         btrfs_exit_sysfs();
1346         btrfs_cleanup_fs_uuids();
1347         btrfs_exit_compress();
1348 }
1349
1350 module_init(init_btrfs_fs)
1351 module_exit(exit_btrfs_fs)
1352
1353 MODULE_LICENSE("GPL");