fs/btrfs/super.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2007 Oracle.  All rights reserved.
   4  */
   5
   6 #include <linux/blkdev.h>
   7 #include <linux/module.h>
   8 #include <linux/fs.h>
   9 #include <linux/pagemap.h>
  10 #include <linux/highmem.h>
  11 #include <linux/time.h>
  12 #include <linux/init.h>
  13 #include <linux/seq_file.h>
  14 #include <linux/string.h>
  15 #include <linux/backing-dev.h>
  16 #include <linux/mount.h>
  17 #include <linux/writeback.h>
  18 #include <linux/statfs.h>
  19 #include <linux/compat.h>
  20 #include <linux/parser.h>
  21 #include <linux/ctype.h>
  22 #include <linux/namei.h>
  23 #include <linux/miscdevice.h>
  24 #include <linux/magic.h>
  25 #include <linux/slab.h>
  26 #include <linux/ratelimit.h>
  27 #include <linux/crc32c.h>
  28 #include <linux/btrfs.h>
  29 #include <linux/security.h>
  30 #include "messages.h"
  31 #include "delayed-inode.h"
  32 #include "ctree.h"
  33 #include "disk-io.h"
  34 #include "transaction.h"
  35 #include "btrfs_inode.h"
  36 #include "print-tree.h"
  37 #include "props.h"
  38 #include "xattr.h"
  39 #include "bio.h"
  40 #include "export.h"
  41 #include "compression.h"
  42 #include "rcu-string.h"
  43 #include "dev-replace.h"
  44 #include "free-space-cache.h"
  45 #include "backref.h"
  46 #include "space-info.h"
  47 #include "sysfs.h"
  48 #include "zoned.h"
  49 #include "tests/btrfs-tests.h"
  50 #include "block-group.h"
  51 #include "discard.h"
  52 #include "qgroup.h"
  53 #include "raid56.h"
  54 #include "fs.h"
  55 #include "accessors.h"
  56 #include "defrag.h"
  57 #include "dir-item.h"
  58 #include "ioctl.h"
  59 #include "scrub.h"
  60 #include "verity.h"
  61 #include "super.h"
  62 #include "extent-tree.h"
  63 #define CREATE_TRACE_POINTS
  64 #include <trace/events/btrfs.h>
  65
  66 static const struct super_operations btrfs_super_ops;
  67
  68 /*
  69  * Types for mounting the default subvolume and a subvolume explicitly
  70  * requested by subvol=/path. That way the callchain is straightforward and we
  71  * don't have to play tricks with the mount options and recursive calls to
  72  * btrfs_mount.
  73  *
  74  * The new btrfs_root_fs_type also servers as a tag for the bdev_holder.
  75  */
  76 static struct file_system_type btrfs_fs_type;
  77 static struct file_system_type btrfs_root_fs_type;
  78
  79 static int btrfs_remount(struct super_block *sb, int *flags, char *data);
  80
  81 static void btrfs_put_super(struct super_block *sb)
  82 {
  83         close_ctree(btrfs_sb(sb));
  84 }
  85
  86 enum {
  87         Opt_acl, Opt_noacl,
  88         Opt_clear_cache,
  89         Opt_commit_interval,
  90         Opt_compress,
  91         Opt_compress_force,
  92         Opt_compress_force_type,
  93         Opt_compress_type,
  94         Opt_degraded,
  95         Opt_device,
  96         Opt_fatal_errors,
  97         Opt_flushoncommit, Opt_noflushoncommit,
  98         Opt_max_inline,
  99         Opt_barrier, Opt_nobarrier,
 100         Opt_datacow, Opt_nodatacow,
 101         Opt_datasum, Opt_nodatasum,
 102         Opt_defrag, Opt_nodefrag,
 103         Opt_discard, Opt_nodiscard,
 104         Opt_discard_mode,
 105         Opt_norecovery,
 106         Opt_ratio,
 107         Opt_rescan_uuid_tree,
 108         Opt_skip_balance,
 109         Opt_space_cache, Opt_no_space_cache,
 110         Opt_space_cache_version,
 111         Opt_ssd, Opt_nossd,
 112         Opt_ssd_spread, Opt_nossd_spread,
 113         Opt_subvol,
 114         Opt_subvol_empty,
 115         Opt_subvolid,
 116         Opt_thread_pool,
 117         Opt_treelog, Opt_notreelog,
 118         Opt_user_subvol_rm_allowed,
 119
 120         /* Rescue options */
 121         Opt_rescue,
 122         Opt_usebackuproot,
 123         Opt_nologreplay,
 124         Opt_ignorebadroots,
 125         Opt_ignoredatacsums,
 126         Opt_rescue_all,
 127
 128         /* Deprecated options */
 129         Opt_recovery,
 130         Opt_inode_cache, Opt_noinode_cache,
 131
 132         /* Debugging options */
 133         Opt_enospc_debug, Opt_noenospc_debug,
 134 #ifdef CONFIG_BTRFS_DEBUG
 135         Opt_fragment_data, Opt_fragment_metadata, Opt_fragment_all,
 136 #endif
 137 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 138         Opt_ref_verify,
 139 #endif
 140         Opt_err,
 141 };
 142
 143 static const match_table_t tokens = {
 144         {Opt_acl, "acl"},
 145         {Opt_noacl, "noacl"},
 146         {Opt_clear_cache, "clear_cache"},
 147         {Opt_commit_interval, "commit=%u"},
 148         {Opt_compress, "compress"},
 149         {Opt_compress_type, "compress=%s"},
 150         {Opt_compress_force, "compress-force"},
 151         {Opt_compress_force_type, "compress-force=%s"},
 152         {Opt_degraded, "degraded"},
 153         {Opt_device, "device=%s"},
 154         {Opt_fatal_errors, "fatal_errors=%s"},
 155         {Opt_flushoncommit, "flushoncommit"},
 156         {Opt_noflushoncommit, "noflushoncommit"},
 157         {Opt_inode_cache, "inode_cache"},
 158         {Opt_noinode_cache, "noinode_cache"},
 159         {Opt_max_inline, "max_inline=%s"},
 160         {Opt_barrier, "barrier"},
 161         {Opt_nobarrier, "nobarrier"},
 162         {Opt_datacow, "datacow"},
 163         {Opt_nodatacow, "nodatacow"},
 164         {Opt_datasum, "datasum"},
 165         {Opt_nodatasum, "nodatasum"},
 166         {Opt_defrag, "autodefrag"},
 167         {Opt_nodefrag, "noautodefrag"},
 168         {Opt_discard, "discard"},
 169         {Opt_discard_mode, "discard=%s"},
 170         {Opt_nodiscard, "nodiscard"},
 171         {Opt_norecovery, "norecovery"},
 172         {Opt_ratio, "metadata_ratio=%u"},
 173         {Opt_rescan_uuid_tree, "rescan_uuid_tree"},
 174         {Opt_skip_balance, "skip_balance"},
 175         {Opt_space_cache, "space_cache"},
 176         {Opt_no_space_cache, "nospace_cache"},
 177         {Opt_space_cache_version, "space_cache=%s"},
 178         {Opt_ssd, "ssd"},
 179         {Opt_nossd, "nossd"},
 180         {Opt_ssd_spread, "ssd_spread"},
 181         {Opt_nossd_spread, "nossd_spread"},
 182         {Opt_subvol, "subvol=%s"},
 183         {Opt_subvol_empty, "subvol="},
 184         {Opt_subvolid, "subvolid=%s"},
 185         {Opt_thread_pool, "thread_pool=%u"},
 186         {Opt_treelog, "treelog"},
 187         {Opt_notreelog, "notreelog"},
 188         {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"},
 189
 190         /* Rescue options */
 191         {Opt_rescue, "rescue=%s"},
 192         /* Deprecated, with alias rescue=nologreplay */
 193         {Opt_nologreplay, "nologreplay"},
 194         /* Deprecated, with alias rescue=usebackuproot */
 195         {Opt_usebackuproot, "usebackuproot"},
 196
 197         /* Deprecated options */
 198         {Opt_recovery, "recovery"},
 199
 200         /* Debugging options */
 201         {Opt_enospc_debug, "enospc_debug"},
 202         {Opt_noenospc_debug, "noenospc_debug"},
 203 #ifdef CONFIG_BTRFS_DEBUG
 204         {Opt_fragment_data, "fragment=data"},
 205         {Opt_fragment_metadata, "fragment=metadata"},
 206         {Opt_fragment_all, "fragment=all"},
 207 #endif
 208 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 209         {Opt_ref_verify, "ref_verify"},
 210 #endif
 211         {Opt_err, NULL},
 212 };
 213
 214 static const match_table_t rescue_tokens = {
 215         {Opt_usebackuproot, "usebackuproot"},
 216         {Opt_nologreplay, "nologreplay"},
 217         {Opt_ignorebadroots, "ignorebadroots"},
 218         {Opt_ignorebadroots, "ibadroots"},
 219         {Opt_ignoredatacsums, "ignoredatacsums"},
 220         {Opt_ignoredatacsums, "idatacsums"},
 221         {Opt_rescue_all, "all"},
 222         {Opt_err, NULL},
 223 };
 224
 225 static bool check_ro_option(struct btrfs_fs_info *fs_info, unsigned long opt,
 226                             const char *opt_name)
 227 {
 228         if (fs_info->mount_opt & opt) {
 229                 btrfs_err(fs_info, "%s must be used with ro mount option",
 230                           opt_name);
 231                 return true;
 232         }
 233         return false;
 234 }
 235
 236 static int parse_rescue_options(struct btrfs_fs_info *info, const char *options)
 237 {
 238         char *opts;
 239         char *orig;
 240         char *p;
 241         substring_t args[MAX_OPT_ARGS];
 242         int ret = 0;
 243
 244         opts = kstrdup(options, GFP_KERNEL);
 245         if (!opts)
 246                 return -ENOMEM;
 247         orig = opts;
 248
 249         while ((p = strsep(&opts, ":")) != NULL) {
 250                 int token;
 251
 252                 if (!*p)
 253                         continue;
 254                 token = match_token(p, rescue_tokens, args);
 255                 switch (token){
 256                 case Opt_usebackuproot:
 257                         btrfs_info(info,
 258                                    "trying to use backup root at mount time");
 259                         btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
 260                         break;
 261                 case Opt_nologreplay:
 262                         btrfs_set_and_info(info, NOLOGREPLAY,
 263                                            "disabling log replay at mount time");
 264                         break;
 265                 case Opt_ignorebadroots:
 266                         btrfs_set_and_info(info, IGNOREBADROOTS,
 267                                            "ignoring bad roots");
 268                         break;
 269                 case Opt_ignoredatacsums:
 270                         btrfs_set_and_info(info, IGNOREDATACSUMS,
 271                                            "ignoring data csums");
 272                         break;
 273                 case Opt_rescue_all:
 274                         btrfs_info(info, "enabling all of the rescue options");
 275                         btrfs_set_and_info(info, IGNOREDATACSUMS,
 276                                            "ignoring data csums");
 277                         btrfs_set_and_info(info, IGNOREBADROOTS,
 278                                            "ignoring bad roots");
 279                         btrfs_set_and_info(info, NOLOGREPLAY,
 280                                            "disabling log replay at mount time");
 281                         break;
 282                 case Opt_err:
 283                         btrfs_info(info, "unrecognized rescue option '%s'", p);
 284                         ret = -EINVAL;
 285                         goto out;
 286                 default:
 287                         break;
 288                 }
 289
 290         }
 291 out:
 292         kfree(orig);
 293         return ret;
 294 }
 295
 296 /*
 297  * Regular mount options parser.  Everything that is needed only when
 298  * reading in a new superblock is parsed here.
 299  * XXX JDM: This needs to be cleaned up for remount.
 300  */
 301 int btrfs_parse_options(struct btrfs_fs_info *info, char *options,
 302                         unsigned long new_flags)
 303 {
 304         substring_t args[MAX_OPT_ARGS];
 305         char *p, *num;
 306         int intarg;
 307         int ret = 0;
 308         char *compress_type;
 309         bool compress_force = false;
 310         enum btrfs_compression_type saved_compress_type;
 311         int saved_compress_level;
 312         bool saved_compress_force;
 313         int no_compress = 0;
 314         const bool remounting = test_bit(BTRFS_FS_STATE_REMOUNTING, &info->fs_state);
 315
 316         if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
 317                 btrfs_set_opt(info->mount_opt, FREE_SPACE_TREE);
 318         else if (btrfs_free_space_cache_v1_active(info)) {
 319                 if (btrfs_is_zoned(info)) {
 320                         btrfs_info(info,
 321                         "zoned: clearing existing space cache");
 322                         btrfs_set_super_cache_generation(info->super_copy, 0);
 323                 } else {
 324                         btrfs_set_opt(info->mount_opt, SPACE_CACHE);
 325                 }
 326         }
 327
 328         /*
 329          * Even the options are empty, we still need to do extra check
 330          * against new flags
 331          */
 332         if (!options)
 333                 goto check;
 334
 335         while ((p = strsep(&options, ",")) != NULL) {
 336                 int token;
 337                 if (!*p)
 338                         continue;
 339
 340                 token = match_token(p, tokens, args);
 341                 switch (token) {
 342                 case Opt_degraded:
 343                         btrfs_info(info, "allowing degraded mounts");
 344                         btrfs_set_opt(info->mount_opt, DEGRADED);
 345                         break;
 346                 case Opt_subvol:
 347                 case Opt_subvol_empty:
 348                 case Opt_subvolid:
 349                 case Opt_device:
 350                         /*
 351                          * These are parsed by btrfs_parse_subvol_options or
 352                          * btrfs_parse_device_options and can be ignored here.
 353                          */
 354                         break;
 355                 case Opt_nodatasum:
 356                         btrfs_set_and_info(info, NODATASUM,
 357                                            "setting nodatasum");
 358                         break;
 359                 case Opt_datasum:
 360                         if (btrfs_test_opt(info, NODATASUM)) {
 361                                 if (btrfs_test_opt(info, NODATACOW))
 362                                         btrfs_info(info,
 363                                                    "setting datasum, datacow enabled");
 364                                 else
 365                                         btrfs_info(info, "setting datasum");
 366                         }
 367                         btrfs_clear_opt(info->mount_opt, NODATACOW);
 368                         btrfs_clear_opt(info->mount_opt, NODATASUM);
 369                         break;
 370                 case Opt_nodatacow:
 371                         if (!btrfs_test_opt(info, NODATACOW)) {
 372                                 if (!btrfs_test_opt(info, COMPRESS) ||
 373                                     !btrfs_test_opt(info, FORCE_COMPRESS)) {
 374                                         btrfs_info(info,
 375                                                    "setting nodatacow, compression disabled");
 376                                 } else {
 377                                         btrfs_info(info, "setting nodatacow");
 378                                 }
 379                         }
 380                         btrfs_clear_opt(info->mount_opt, COMPRESS);
 381                         btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 382                         btrfs_set_opt(info->mount_opt, NODATACOW);
 383                         btrfs_set_opt(info->mount_opt, NODATASUM);
 384                         break;
 385                 case Opt_datacow:
 386                         btrfs_clear_and_info(info, NODATACOW,
 387                                              "setting datacow");
 388                         break;
 389                 case Opt_compress_force:
 390                 case Opt_compress_force_type:
 391                         compress_force = true;
 392                         fallthrough;
 393                 case Opt_compress:
 394                 case Opt_compress_type:
 395                         saved_compress_type = btrfs_test_opt(info,
 396                                                              COMPRESS) ?
 397                                 info->compress_type : BTRFS_COMPRESS_NONE;
 398                         saved_compress_force =
 399                                 btrfs_test_opt(info, FORCE_COMPRESS);
 400                         saved_compress_level = info->compress_level;
 401                         if (token == Opt_compress ||
 402                             token == Opt_compress_force ||
 403                             strncmp(args[0].from, "zlib", 4) == 0) {
 404                                 compress_type = "zlib";
 405
 406                                 info->compress_type = BTRFS_COMPRESS_ZLIB;
 407                                 info->compress_level = BTRFS_ZLIB_DEFAULT_LEVEL;
 408                                 /*
 409                                  * args[0] contains uninitialized data since
 410                                  * for these tokens we don't expect any
 411                                  * parameter.
 412                                  */
 413                                 if (token != Opt_compress &&
 414                                     token != Opt_compress_force)
 415                                         info->compress_level =
 416                                           btrfs_compress_str2level(
 417                                                         BTRFS_COMPRESS_ZLIB,
 418                                                         args[0].from + 4);
 419                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 420                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 421                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 422                                 no_compress = 0;
 423                         } else if (strncmp(args[0].from, "lzo", 3) == 0) {
 424                                 compress_type = "lzo";
 425                                 info->compress_type = BTRFS_COMPRESS_LZO;
 426                                 info->compress_level = 0;
 427                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 428                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 429                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 430                                 btrfs_set_fs_incompat(info, COMPRESS_LZO);
 431                                 no_compress = 0;
 432                         } else if (strncmp(args[0].from, "zstd", 4) == 0) {
 433                                 compress_type = "zstd";
 434                                 info->compress_type = BTRFS_COMPRESS_ZSTD;
 435                                 info->compress_level =
 436                                         btrfs_compress_str2level(
 437                                                          BTRFS_COMPRESS_ZSTD,
 438                                                          args[0].from + 4);
 439                                 btrfs_set_opt(info->mount_opt, COMPRESS);
 440                                 btrfs_clear_opt(info->mount_opt, NODATACOW);
 441                                 btrfs_clear_opt(info->mount_opt, NODATASUM);
 442                                 btrfs_set_fs_incompat(info, COMPRESS_ZSTD);
 443                                 no_compress = 0;
 444                         } else if (strncmp(args[0].from, "no", 2) == 0) {
 445                                 compress_type = "no";
 446                                 info->compress_level = 0;
 447                                 info->compress_type = 0;
 448                                 btrfs_clear_opt(info->mount_opt, COMPRESS);
 449                                 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 450                                 compress_force = false;
 451                                 no_compress++;
 452                         } else {
 453                                 btrfs_err(info, "unrecognized compression value %s",
 454                                           args[0].from);
 455                                 ret = -EINVAL;
 456                                 goto out;
 457                         }
 458
 459                         if (compress_force) {
 460                                 btrfs_set_opt(info->mount_opt, FORCE_COMPRESS);
 461                         } else {
 462                                 /*
 463                                  * If we remount from compress-force=xxx to
 464                                  * compress=xxx, we need clear FORCE_COMPRESS
 465                                  * flag, otherwise, there is no way for users
 466                                  * to disable forcible compression separately.
 467                                  */
 468                                 btrfs_clear_opt(info->mount_opt, FORCE_COMPRESS);
 469                         }
 470                         if (no_compress == 1) {
 471                                 btrfs_info(info, "use no compression");
 472                         } else if ((info->compress_type != saved_compress_type) ||
 473                                    (compress_force != saved_compress_force) ||
 474                                    (info->compress_level != saved_compress_level)) {
 475                                 btrfs_info(info, "%s %s compression, level %d",
 476                                            (compress_force) ? "force" : "use",
 477                                            compress_type, info->compress_level);
 478                         }
 479                         compress_force = false;
 480                         break;
 481                 case Opt_ssd:
 482                         btrfs_set_and_info(info, SSD,
 483                                            "enabling ssd optimizations");
 484                         btrfs_clear_opt(info->mount_opt, NOSSD);
 485                         break;
 486                 case Opt_ssd_spread:
 487                         btrfs_set_and_info(info, SSD,
 488                                            "enabling ssd optimizations");
 489                         btrfs_set_and_info(info, SSD_SPREAD,
 490                                            "using spread ssd allocation scheme");
 491                         btrfs_clear_opt(info->mount_opt, NOSSD);
 492                         break;
 493                 case Opt_nossd:
 494                         btrfs_set_opt(info->mount_opt, NOSSD);
 495                         btrfs_clear_and_info(info, SSD,
 496                                              "not using ssd optimizations");
 497                         fallthrough;
 498                 case Opt_nossd_spread:
 499                         btrfs_clear_and_info(info, SSD_SPREAD,
 500                                              "not using spread ssd allocation scheme");
 501                         break;
 502                 case Opt_barrier:
 503                         btrfs_clear_and_info(info, NOBARRIER,
 504                                              "turning on barriers");
 505                         break;
 506                 case Opt_nobarrier:
 507                         btrfs_set_and_info(info, NOBARRIER,
 508                                            "turning off barriers");
 509                         break;
 510                 case Opt_thread_pool:
 511                         ret = match_int(&args[0], &intarg);
 512                         if (ret) {
 513                                 btrfs_err(info, "unrecognized thread_pool value %s",
 514                                           args[0].from);
 515                                 goto out;
 516                         } else if (intarg == 0) {
 517                                 btrfs_err(info, "invalid value 0 for thread_pool");
 518                                 ret = -EINVAL;
 519                                 goto out;
 520                         }
 521                         info->thread_pool_size = intarg;
 522                         break;
 523                 case Opt_max_inline:
 524                         num = match_strdup(&args[0]);
 525                         if (num) {
 526                                 info->max_inline = memparse(num, NULL);
 527                                 kfree(num);
 528
 529                                 if (info->max_inline) {
 530                                         info->max_inline = min_t(u64,
 531                                                 info->max_inline,
 532                                                 info->sectorsize);
 533                                 }
 534                                 btrfs_info(info, "max_inline at %llu",
 535                                            info->max_inline);
 536                         } else {
 537                                 ret = -ENOMEM;
 538                                 goto out;
 539                         }
 540                         break;
 541                 case Opt_acl:
 542 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
 543                         info->sb->s_flags |= SB_POSIXACL;
 544                         break;
 545 #else
 546                         btrfs_err(info, "support for ACL not compiled in!");
 547                         ret = -EINVAL;
 548                         goto out;
 549 #endif
 550                 case Opt_noacl:
 551                         info->sb->s_flags &= ~SB_POSIXACL;
 552                         break;
 553                 case Opt_notreelog:
 554                         btrfs_set_and_info(info, NOTREELOG,
 555                                            "disabling tree log");
 556                         break;
 557                 case Opt_treelog:
 558                         btrfs_clear_and_info(info, NOTREELOG,
 559                                              "enabling tree log");
 560                         break;
 561                 case Opt_norecovery:
 562                 case Opt_nologreplay:
 563                         btrfs_warn(info,
 564                 "'nologreplay' is deprecated, use 'rescue=nologreplay' instead");
 565                         btrfs_set_and_info(info, NOLOGREPLAY,
 566                                            "disabling log replay at mount time");
 567                         break;
 568                 case Opt_flushoncommit:
 569                         btrfs_set_and_info(info, FLUSHONCOMMIT,
 570                                            "turning on flush-on-commit");
 571                         break;
 572                 case Opt_noflushoncommit:
 573                         btrfs_clear_and_info(info, FLUSHONCOMMIT,
 574                                              "turning off flush-on-commit");
 575                         break;
 576                 case Opt_ratio:
 577                         ret = match_int(&args[0], &intarg);
 578                         if (ret) {
 579                                 btrfs_err(info, "unrecognized metadata_ratio value %s",
 580                                           args[0].from);
 581                                 goto out;
 582                         }
 583                         info->metadata_ratio = intarg;
 584                         btrfs_info(info, "metadata ratio %u",
 585                                    info->metadata_ratio);
 586                         break;
 587                 case Opt_discard:
 588                 case Opt_discard_mode:
 589                         if (token == Opt_discard ||
 590                             strcmp(args[0].from, "sync") == 0) {
 591                                 btrfs_clear_opt(info->mount_opt, DISCARD_ASYNC);
 592                                 btrfs_set_and_info(info, DISCARD_SYNC,
 593                                                    "turning on sync discard");
 594                         } else if (strcmp(args[0].from, "async") == 0) {
 595                                 btrfs_clear_opt(info->mount_opt, DISCARD_SYNC);
 596                                 btrfs_set_and_info(info, DISCARD_ASYNC,
 597                                                    "turning on async discard");
 598                         } else {
 599                                 btrfs_err(info, "unrecognized discard mode value %s",
 600                                           args[0].from);
 601                                 ret = -EINVAL;
 602                                 goto out;
 603                         }
 604                         btrfs_clear_opt(info->mount_opt, NODISCARD);
 605                         break;
 606                 case Opt_nodiscard:
 607                         btrfs_clear_and_info(info, DISCARD_SYNC,
 608                                              "turning off discard");
 609                         btrfs_clear_and_info(info, DISCARD_ASYNC,
 610                                              "turning off async discard");
 611                         btrfs_set_opt(info->mount_opt, NODISCARD);
 612                         break;
 613                 case Opt_space_cache:
 614                 case Opt_space_cache_version:
 615                         /*
 616                          * We already set FREE_SPACE_TREE above because we have
 617                          * compat_ro(FREE_SPACE_TREE) set, and we aren't going
 618                          * to allow v1 to be set for extent tree v2, simply
 619                          * ignore this setting if we're extent tree v2.
 620                          */
 621                         if (btrfs_fs_incompat(info, EXTENT_TREE_V2))
 622                                 break;
 623                         if (token == Opt_space_cache ||
 624                             strcmp(args[0].from, "v1") == 0) {
 625                                 btrfs_clear_opt(info->mount_opt,
 626                                                 FREE_SPACE_TREE);
 627                                 btrfs_set_and_info(info, SPACE_CACHE,
 628                                            "enabling disk space caching");
 629                         } else if (strcmp(args[0].from, "v2") == 0) {
 630                                 btrfs_clear_opt(info->mount_opt,
 631                                                 SPACE_CACHE);
 632                                 btrfs_set_and_info(info, FREE_SPACE_TREE,
 633                                                    "enabling free space tree");
 634                         } else {
 635                                 btrfs_err(info, "unrecognized space_cache value %s",
 636                                           args[0].from);
 637                                 ret = -EINVAL;
 638                                 goto out;
 639                         }
 640                         break;
 641                 case Opt_rescan_uuid_tree:
 642                         btrfs_set_opt(info->mount_opt, RESCAN_UUID_TREE);
 643                         break;
 644                 case Opt_no_space_cache:
 645                         /*
 646                          * We cannot operate without the free space tree with
 647                          * extent tree v2, ignore this option.
 648                          */
 649                         if (btrfs_fs_incompat(info, EXTENT_TREE_V2))
 650                                 break;
 651                         if (btrfs_test_opt(info, SPACE_CACHE)) {
 652                                 btrfs_clear_and_info(info, SPACE_CACHE,
 653                                              "disabling disk space caching");
 654                         }
 655                         if (btrfs_test_opt(info, FREE_SPACE_TREE)) {
 656                                 btrfs_clear_and_info(info, FREE_SPACE_TREE,
 657                                              "disabling free space tree");
 658                         }
 659                         break;
 660                 case Opt_inode_cache:
 661                 case Opt_noinode_cache:
 662                         btrfs_warn(info,
 663         "the 'inode_cache' option is deprecated and has no effect since 5.11");
 664                         break;
 665                 case Opt_clear_cache:
 666                         /*
 667                          * We cannot clear the free space tree with extent tree
 668                          * v2, ignore this option.
 669                          */
 670                         if (btrfs_fs_incompat(info, EXTENT_TREE_V2))
 671                                 break;
 672                         btrfs_set_and_info(info, CLEAR_CACHE,
 673                                            "force clearing of disk cache");
 674                         break;
 675                 case Opt_user_subvol_rm_allowed:
 676                         btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED);
 677                         break;
 678                 case Opt_enospc_debug:
 679                         btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG);
 680                         break;
 681                 case Opt_noenospc_debug:
 682                         btrfs_clear_opt(info->mount_opt, ENOSPC_DEBUG);
 683                         break;
 684                 case Opt_defrag:
 685                         btrfs_set_and_info(info, AUTO_DEFRAG,
 686                                            "enabling auto defrag");
 687                         break;
 688                 case Opt_nodefrag:
 689                         btrfs_clear_and_info(info, AUTO_DEFRAG,
 690                                              "disabling auto defrag");
 691                         break;
 692                 case Opt_recovery:
 693                 case Opt_usebackuproot:
 694                         btrfs_warn(info,
 695                         "'%s' is deprecated, use 'rescue=usebackuproot' instead",
 696                                    token == Opt_recovery ? "recovery" :
 697                                    "usebackuproot");
 698                         btrfs_info(info,
 699                                    "trying to use backup root at mount time");
 700                         btrfs_set_opt(info->mount_opt, USEBACKUPROOT);
 701                         break;
 702                 case Opt_skip_balance:
 703                         btrfs_set_opt(info->mount_opt, SKIP_BALANCE);
 704                         break;
 705                 case Opt_fatal_errors:
 706                         if (strcmp(args[0].from, "panic") == 0) {
 707                                 btrfs_set_opt(info->mount_opt,
 708                                               PANIC_ON_FATAL_ERROR);
 709                         } else if (strcmp(args[0].from, "bug") == 0) {
 710                                 btrfs_clear_opt(info->mount_opt,
 711                                               PANIC_ON_FATAL_ERROR);
 712                         } else {
 713                                 btrfs_err(info, "unrecognized fatal_errors value %s",
 714                                           args[0].from);
 715                                 ret = -EINVAL;
 716                                 goto out;
 717                         }
 718                         break;
 719                 case Opt_commit_interval:
 720                         intarg = 0;
 721                         ret = match_int(&args[0], &intarg);
 722                         if (ret) {
 723                                 btrfs_err(info, "unrecognized commit_interval value %s",
 724                                           args[0].from);
 725                                 ret = -EINVAL;
 726                                 goto out;
 727                         }
 728                         if (intarg == 0) {
 729                                 btrfs_info(info,
 730                                            "using default commit interval %us",
 731                                            BTRFS_DEFAULT_COMMIT_INTERVAL);
 732                                 intarg = BTRFS_DEFAULT_COMMIT_INTERVAL;
 733                         } else if (intarg > 300) {
 734                                 btrfs_warn(info, "excessive commit interval %d",
 735                                            intarg);
 736                         }
 737                         info->commit_interval = intarg;
 738                         break;
 739                 case Opt_rescue:
 740                         ret = parse_rescue_options(info, args[0].from);
 741                         if (ret < 0) {
 742                                 btrfs_err(info, "unrecognized rescue value %s",
 743                                           args[0].from);
 744                                 goto out;
 745                         }
 746                         break;
 747 #ifdef CONFIG_BTRFS_DEBUG
 748                 case Opt_fragment_all:
 749                         btrfs_info(info, "fragmenting all space");
 750                         btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
 751                         btrfs_set_opt(info->mount_opt, FRAGMENT_METADATA);
 752                         break;
 753                 case Opt_fragment_metadata:
 754                         btrfs_info(info, "fragmenting metadata");
 755                         btrfs_set_opt(info->mount_opt,
 756                                       FRAGMENT_METADATA);
 757                         break;
 758                 case Opt_fragment_data:
 759                         btrfs_info(info, "fragmenting data");
 760                         btrfs_set_opt(info->mount_opt, FRAGMENT_DATA);
 761                         break;
 762 #endif
 763 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
 764                 case Opt_ref_verify:
 765                         btrfs_info(info, "doing ref verification");
 766                         btrfs_set_opt(info->mount_opt, REF_VERIFY);
 767                         break;
 768 #endif
 769                 case Opt_err:
 770                         btrfs_err(info, "unrecognized mount option '%s'", p);
 771                         ret = -EINVAL;
 772                         goto out;
 773                 default:
 774                         break;
 775                 }
 776         }
 777 check:
 778         /* We're read-only, don't have to check. */
 779         if (new_flags & SB_RDONLY)
 780                 goto out;
 781
 782         if (check_ro_option(info, BTRFS_MOUNT_NOLOGREPLAY, "nologreplay") ||
 783             check_ro_option(info, BTRFS_MOUNT_IGNOREBADROOTS, "ignorebadroots") ||
 784             check_ro_option(info, BTRFS_MOUNT_IGNOREDATACSUMS, "ignoredatacsums"))
 785                 ret = -EINVAL;
 786 out:
 787         if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE) &&
 788             !btrfs_test_opt(info, FREE_SPACE_TREE) &&
 789             !btrfs_test_opt(info, CLEAR_CACHE)) {
 790                 btrfs_err(info, "cannot disable free space tree");
 791                 ret = -EINVAL;
 792         }
 793         if (btrfs_fs_compat_ro(info, BLOCK_GROUP_TREE) &&
 794              !btrfs_test_opt(info, FREE_SPACE_TREE)) {
 795                 btrfs_err(info, "cannot disable free space tree with block-group-tree feature");
 796                 ret = -EINVAL;
 797         }
 798         if (!ret)
 799                 ret = btrfs_check_mountopts_zoned(info);
 800         if (!ret && !remounting) {
 801                 if (btrfs_test_opt(info, SPACE_CACHE))
 802                         btrfs_info(info, "disk space caching is enabled");
 803                 if (btrfs_test_opt(info, FREE_SPACE_TREE))
 804                         btrfs_info(info, "using free space tree");
 805         }
 806         return ret;
 807 }
 808
 809 /*
 810  * Parse mount options that are required early in the mount process.
 811  *
 812  * All other options will be parsed on much later in the mount process and
 813  * only when we need to allocate a new super block.
 814  */
 815 static int btrfs_parse_device_options(const char *options, blk_mode_t flags)
 816 {
 817         substring_t args[MAX_OPT_ARGS];
 818         char *device_name, *opts, *orig, *p;
 819         struct btrfs_device *device = NULL;
 820         int error = 0;
 821
 822         lockdep_assert_held(&uuid_mutex);
 823
 824         if (!options)
 825                 return 0;
 826
 827         /*
 828          * strsep changes the string, duplicate it because btrfs_parse_options
 829          * gets called later
 830          */
 831         opts = kstrdup(options, GFP_KERNEL);
 832         if (!opts)
 833                 return -ENOMEM;
 834         orig = opts;
 835
 836         while ((p = strsep(&opts, ",")) != NULL) {
 837                 int token;
 838
 839                 if (!*p)
 840                         continue;
 841
 842                 token = match_token(p, tokens, args);
 843                 if (token == Opt_device) {
 844                         device_name = match_strdup(&args[0]);
 845                         if (!device_name) {
 846                                 error = -ENOMEM;
 847                                 goto out;
 848                         }
 849                         device = btrfs_scan_one_device(device_name, flags, false);
 850                         kfree(device_name);
 851                         if (IS_ERR(device)) {
 852                                 error = PTR_ERR(device);
 853                                 goto out;
 854                         }
 855                 }
 856         }
 857
 858 out:
 859         kfree(orig);
 860         return error;
 861 }
 862
 863 /*
 864  * Parse mount options that are related to subvolume id
 865  *
 866  * The value is later passed to mount_subvol()
 867  */
 868 static int btrfs_parse_subvol_options(const char *options, char **subvol_name,
 869                 u64 *subvol_objectid)
 870 {
 871         substring_t args[MAX_OPT_ARGS];
 872         char *opts, *orig, *p;
 873         int error = 0;
 874         u64 subvolid;
 875
 876         if (!options)
 877                 return 0;
 878
 879         /*
 880          * strsep changes the string, duplicate it because
 881          * btrfs_parse_device_options gets called later
 882          */
 883         opts = kstrdup(options, GFP_KERNEL);
 884         if (!opts)
 885                 return -ENOMEM;
 886         orig = opts;
 887
 888         while ((p = strsep(&opts, ",")) != NULL) {
 889                 int token;
 890                 if (!*p)
 891                         continue;
 892
 893                 token = match_token(p, tokens, args);
 894                 switch (token) {
 895                 case Opt_subvol:
 896                         kfree(*subvol_name);
 897                         *subvol_name = match_strdup(&args[0]);
 898                         if (!*subvol_name) {
 899                                 error = -ENOMEM;
 900                                 goto out;
 901                         }
 902                         break;
 903                 case Opt_subvolid:
 904                         error = match_u64(&args[0], &subvolid);
 905                         if (error)
 906                                 goto out;
 907
 908                         /* we want the original fs_tree */
 909                         if (subvolid == 0)
 910                                 subvolid = BTRFS_FS_TREE_OBJECTID;
 911
 912                         *subvol_objectid = subvolid;
 913                         break;
 914                 default:
 915                         break;
 916                 }
 917         }
 918
 919 out:
 920         kfree(orig);
 921         return error;
 922 }
 923
 924 char *btrfs_get_subvol_name_from_objectid(struct btrfs_fs_info *fs_info,
 925                                           u64 subvol_objectid)
 926 {
 927         struct btrfs_root *root = fs_info->tree_root;
 928         struct btrfs_root *fs_root = NULL;
 929         struct btrfs_root_ref *root_ref;
 930         struct btrfs_inode_ref *inode_ref;
 931         struct btrfs_key key;
 932         struct btrfs_path *path = NULL;
 933         char *name = NULL, *ptr;
 934         u64 dirid;
 935         int len;
 936         int ret;
 937
 938         path = btrfs_alloc_path();
 939         if (!path) {
 940                 ret = -ENOMEM;
 941                 goto err;
 942         }
 943
 944         name = kmalloc(PATH_MAX, GFP_KERNEL);
 945         if (!name) {
 946                 ret = -ENOMEM;
 947                 goto err;
 948         }
 949         ptr = name + PATH_MAX - 1;
 950         ptr[0] = '\0';
 951
 952         /*
 953          * Walk up the subvolume trees in the tree of tree roots by root
 954          * backrefs until we hit the top-level subvolume.
 955          */
 956         while (subvol_objectid != BTRFS_FS_TREE_OBJECTID) {
 957                 key.objectid = subvol_objectid;
 958                 key.type = BTRFS_ROOT_BACKREF_KEY;
 959                 key.offset = (u64)-1;
 960
 961                 ret = btrfs_search_backwards(root, &key, path);
 962                 if (ret < 0) {
 963                         goto err;
 964                 } else if (ret > 0) {
 965                         ret = -ENOENT;
 966                         goto err;
 967                 }
 968
 969                 subvol_objectid = key.offset;
 970
 971                 root_ref = btrfs_item_ptr(path->nodes[0], path->slots[0],
 972                                           struct btrfs_root_ref);
 973                 len = btrfs_root_ref_name_len(path->nodes[0], root_ref);
 974                 ptr -= len + 1;
 975                 if (ptr < name) {
 976                         ret = -ENAMETOOLONG;
 977                         goto err;
 978                 }
 979                 read_extent_buffer(path->nodes[0], ptr + 1,
 980                                    (unsigned long)(root_ref + 1), len);
 981                 ptr[0] = '/';
 982                 dirid = btrfs_root_ref_dirid(path->nodes[0], root_ref);
 983                 btrfs_release_path(path);
 984
 985                 fs_root = btrfs_get_fs_root(fs_info, subvol_objectid, true);
 986                 if (IS_ERR(fs_root)) {
 987                         ret = PTR_ERR(fs_root);
 988                         fs_root = NULL;
 989                         goto err;
 990                 }
 991
 992                 /*
 993                  * Walk up the filesystem tree by inode refs until we hit the
 994                  * root directory.
 995                  */
 996                 while (dirid != BTRFS_FIRST_FREE_OBJECTID) {
 997                         key.objectid = dirid;
 998                         key.type = BTRFS_INODE_REF_KEY;
 999                         key.offset = (u64)-1;
1000
1001                         ret = btrfs_search_backwards(fs_root, &key, path);
1002                         if (ret < 0) {
1003                                 goto err;
1004                         } else if (ret > 0) {
1005                                 ret = -ENOENT;
1006                                 goto err;
1007                         }
1008
1009                         dirid = key.offset;
1010
1011                         inode_ref = btrfs_item_ptr(path->nodes[0],
1012                                                    path->slots[0],
1013                                                    struct btrfs_inode_ref);
1014                         len = btrfs_inode_ref_name_len(path->nodes[0],
1015                                                        inode_ref);
1016                         ptr -= len + 1;
1017                         if (ptr < name) {
1018                                 ret = -ENAMETOOLONG;
1019                                 goto err;
1020                         }
1021                         read_extent_buffer(path->nodes[0], ptr + 1,
1022                                            (unsigned long)(inode_ref + 1), len);
1023                         ptr[0] = '/';
1024                         btrfs_release_path(path);
1025                 }
1026                 btrfs_put_root(fs_root);
1027                 fs_root = NULL;
1028         }
1029
1030         btrfs_free_path(path);
1031         if (ptr == name + PATH_MAX - 1) {
1032                 name[0] = '/';
1033                 name[1] = '\0';
1034         } else {
1035                 memmove(name, ptr, name + PATH_MAX - ptr);
1036         }
1037         return name;
1038
1039 err:
1040         btrfs_put_root(fs_root);
1041         btrfs_free_path(path);
1042         kfree(name);
1043         return ERR_PTR(ret);
1044 }
1045
1046 static int get_default_subvol_objectid(struct btrfs_fs_info *fs_info, u64 *objectid)
1047 {
1048         struct btrfs_root *root = fs_info->tree_root;
1049         struct btrfs_dir_item *di;
1050         struct btrfs_path *path;
1051         struct btrfs_key location;
1052         struct fscrypt_str name = FSTR_INIT("default", 7);
1053         u64 dir_id;
1054
1055         path = btrfs_alloc_path();
1056         if (!path)
1057                 return -ENOMEM;
1058
1059         /*
1060          * Find the "default" dir item which points to the root item that we
1061          * will mount by default if we haven't been given a specific subvolume
1062          * to mount.
1063          */
1064         dir_id = btrfs_super_root_dir(fs_info->super_copy);
1065         di = btrfs_lookup_dir_item(NULL, root, path, dir_id, &name, 0);
1066         if (IS_ERR(di)) {
1067                 btrfs_free_path(path);
1068                 return PTR_ERR(di);
1069         }
1070         if (!di) {
1071                 /*
1072                  * Ok the default dir item isn't there.  This is weird since
1073                  * it's always been there, but don't freak out, just try and
1074                  * mount the top-level subvolume.
1075                  */
1076                 btrfs_free_path(path);
1077                 *objectid = BTRFS_FS_TREE_OBJECTID;
1078                 return 0;
1079         }
1080
1081         btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
1082         btrfs_free_path(path);
1083         *objectid = location.objectid;
1084         return 0;
1085 }
1086
1087 static int btrfs_fill_super(struct super_block *sb,
1088                             struct btrfs_fs_devices *fs_devices,
1089                             void *data)
1090 {
1091         struct inode *inode;
1092         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1093         int err;
1094
1095         sb->s_maxbytes = MAX_LFS_FILESIZE;
1096         sb->s_magic = BTRFS_SUPER_MAGIC;
1097         sb->s_op = &btrfs_super_ops;
1098         sb->s_d_op = &btrfs_dentry_operations;
1099         sb->s_export_op = &btrfs_export_ops;
1100 #ifdef CONFIG_FS_VERITY
1101         sb->s_vop = &btrfs_verityops;
1102 #endif
1103         sb->s_xattr = btrfs_xattr_handlers;
1104         sb->s_time_gran = 1;
1105 #ifdef CONFIG_BTRFS_FS_POSIX_ACL
1106         sb->s_flags |= SB_POSIXACL;
1107 #endif
1108         sb->s_flags |= SB_I_VERSION;
1109         sb->s_iflags |= SB_I_CGROUPWB;
1110
1111         err = super_setup_bdi(sb);
1112         if (err) {
1113                 btrfs_err(fs_info, "super_setup_bdi failed");
1114                 return err;
1115         }
1116
1117         err = open_ctree(sb, fs_devices, (char *)data);
1118         if (err) {
1119                 btrfs_err(fs_info, "open_ctree failed");
1120                 return err;
1121         }
1122
1123         inode = btrfs_iget(sb, BTRFS_FIRST_FREE_OBJECTID, fs_info->fs_root);
1124         if (IS_ERR(inode)) {
1125                 err = PTR_ERR(inode);
1126                 btrfs_handle_fs_error(fs_info, err, NULL);
1127                 goto fail_close;
1128         }
1129
1130         sb->s_root = d_make_root(inode);
1131         if (!sb->s_root) {
1132                 err = -ENOMEM;
1133                 goto fail_close;
1134         }
1135
1136         sb->s_flags |= SB_ACTIVE;
1137         return 0;
1138
1139 fail_close:
1140         close_ctree(fs_info);
1141         return err;
1142 }
1143
1144 int btrfs_sync_fs(struct super_block *sb, int wait)
1145 {
1146         struct btrfs_trans_handle *trans;
1147         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1148         struct btrfs_root *root = fs_info->tree_root;
1149
1150         trace_btrfs_sync_fs(fs_info, wait);
1151
1152         if (!wait) {
1153                 filemap_flush(fs_info->btree_inode->i_mapping);
1154                 return 0;
1155         }
1156
1157         btrfs_wait_ordered_roots(fs_info, U64_MAX, 0, (u64)-1);
1158
1159         trans = btrfs_attach_transaction_barrier(root);
1160         if (IS_ERR(trans)) {
1161                 /* no transaction, don't bother */
1162                 if (PTR_ERR(trans) == -ENOENT) {
1163                         /*
1164                          * Exit unless we have some pending changes
1165                          * that need to go through commit
1166                          */
1167                         if (!test_bit(BTRFS_FS_NEED_TRANS_COMMIT,
1168                                       &fs_info->flags))
1169                                 return 0;
1170                         /*
1171                          * A non-blocking test if the fs is frozen. We must not
1172                          * start a new transaction here otherwise a deadlock
1173                          * happens. The pending operations are delayed to the
1174                          * next commit after thawing.
1175                          */
1176                         if (sb_start_write_trylock(sb))
1177                                 sb_end_write(sb);
1178                         else
1179                                 return 0;
1180                         trans = btrfs_start_transaction(root, 0);
1181                 }
1182                 if (IS_ERR(trans))
1183                         return PTR_ERR(trans);
1184         }
1185         return btrfs_commit_transaction(trans);
1186 }
1187
1188 static void print_rescue_option(struct seq_file *seq, const char *s, bool *printed)
1189 {
1190         seq_printf(seq, "%s%s", (*printed) ? ":" : ",rescue=", s);
1191         *printed = true;
1192 }
1193
1194 static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry)
1195 {
1196         struct btrfs_fs_info *info = btrfs_sb(dentry->d_sb);
1197         const char *compress_type;
1198         const char *subvol_name;
1199         bool printed = false;
1200
1201         if (btrfs_test_opt(info, DEGRADED))
1202                 seq_puts(seq, ",degraded");
1203         if (btrfs_test_opt(info, NODATASUM))
1204                 seq_puts(seq, ",nodatasum");
1205         if (btrfs_test_opt(info, NODATACOW))
1206                 seq_puts(seq, ",nodatacow");
1207         if (btrfs_test_opt(info, NOBARRIER))
1208                 seq_puts(seq, ",nobarrier");
1209         if (info->max_inline != BTRFS_DEFAULT_MAX_INLINE)
1210                 seq_printf(seq, ",max_inline=%llu", info->max_inline);
1211         if (info->thread_pool_size !=  min_t(unsigned long,
1212                                              num_online_cpus() + 2, 8))
1213                 seq_printf(seq, ",thread_pool=%u", info->thread_pool_size);
1214         if (btrfs_test_opt(info, COMPRESS)) {
1215                 compress_type = btrfs_compress_type2str(info->compress_type);
1216                 if (btrfs_test_opt(info, FORCE_COMPRESS))
1217                         seq_printf(seq, ",compress-force=%s", compress_type);
1218                 else
1219                         seq_printf(seq, ",compress=%s", compress_type);
1220                 if (info->compress_level)
1221                         seq_printf(seq, ":%d", info->compress_level);
1222         }
1223         if (btrfs_test_opt(info, NOSSD))
1224                 seq_puts(seq, ",nossd");
1225         if (btrfs_test_opt(info, SSD_SPREAD))
1226                 seq_puts(seq, ",ssd_spread");
1227         else if (btrfs_test_opt(info, SSD))
1228                 seq_puts(seq, ",ssd");
1229         if (btrfs_test_opt(info, NOTREELOG))
1230                 seq_puts(seq, ",notreelog");
1231         if (btrfs_test_opt(info, NOLOGREPLAY))
1232                 print_rescue_option(seq, "nologreplay", &printed);
1233         if (btrfs_test_opt(info, USEBACKUPROOT))
1234                 print_rescue_option(seq, "usebackuproot", &printed);
1235         if (btrfs_test_opt(info, IGNOREBADROOTS))
1236                 print_rescue_option(seq, "ignorebadroots", &printed);
1237         if (btrfs_test_opt(info, IGNOREDATACSUMS))
1238                 print_rescue_option(seq, "ignoredatacsums", &printed);
1239         if (btrfs_test_opt(info, FLUSHONCOMMIT))
1240                 seq_puts(seq, ",flushoncommit");
1241         if (btrfs_test_opt(info, DISCARD_SYNC))
1242                 seq_puts(seq, ",discard");
1243         if (btrfs_test_opt(info, DISCARD_ASYNC))
1244                 seq_puts(seq, ",discard=async");
1245         if (!(info->sb->s_flags & SB_POSIXACL))
1246                 seq_puts(seq, ",noacl");
1247         if (btrfs_free_space_cache_v1_active(info))
1248                 seq_puts(seq, ",space_cache");
1249         else if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
1250                 seq_puts(seq, ",space_cache=v2");
1251         else
1252                 seq_puts(seq, ",nospace_cache");
1253         if (btrfs_test_opt(info, RESCAN_UUID_TREE))
1254                 seq_puts(seq, ",rescan_uuid_tree");
1255         if (btrfs_test_opt(info, CLEAR_CACHE))
1256                 seq_puts(seq, ",clear_cache");
1257         if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED))
1258                 seq_puts(seq, ",user_subvol_rm_allowed");
1259         if (btrfs_test_opt(info, ENOSPC_DEBUG))
1260                 seq_puts(seq, ",enospc_debug");
1261         if (btrfs_test_opt(info, AUTO_DEFRAG))
1262                 seq_puts(seq, ",autodefrag");
1263         if (btrfs_test_opt(info, SKIP_BALANCE))
1264                 seq_puts(seq, ",skip_balance");
1265         if (info->metadata_ratio)
1266                 seq_printf(seq, ",metadata_ratio=%u", info->metadata_ratio);
1267         if (btrfs_test_opt(info, PANIC_ON_FATAL_ERROR))
1268                 seq_puts(seq, ",fatal_errors=panic");
1269         if (info->commit_interval != BTRFS_DEFAULT_COMMIT_INTERVAL)
1270                 seq_printf(seq, ",commit=%u", info->commit_interval);
1271 #ifdef CONFIG_BTRFS_DEBUG
1272         if (btrfs_test_opt(info, FRAGMENT_DATA))
1273                 seq_puts(seq, ",fragment=data");
1274         if (btrfs_test_opt(info, FRAGMENT_METADATA))
1275                 seq_puts(seq, ",fragment=metadata");
1276 #endif
1277         if (btrfs_test_opt(info, REF_VERIFY))
1278                 seq_puts(seq, ",ref_verify");
1279         seq_printf(seq, ",subvolid=%llu",
1280                   BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1281         subvol_name = btrfs_get_subvol_name_from_objectid(info,
1282                         BTRFS_I(d_inode(dentry))->root->root_key.objectid);
1283         if (!IS_ERR(subvol_name)) {
1284                 seq_puts(seq, ",subvol=");
1285                 seq_escape(seq, subvol_name, " \t\n\\");
1286                 kfree(subvol_name);
1287         }
1288         return 0;
1289 }
1290
1291 static int btrfs_test_super(struct super_block *s, void *data)
1292 {
1293         struct btrfs_fs_info *p = data;
1294         struct btrfs_fs_info *fs_info = btrfs_sb(s);
1295
1296         return fs_info->fs_devices == p->fs_devices;
1297 }
1298
1299 static int btrfs_set_super(struct super_block *s, void *data)
1300 {
1301         int err = set_anon_super(s, data);
1302         if (!err)
1303                 s->s_fs_info = data;
1304         return err;
1305 }
1306
1307 /*
1308  * subvolumes are identified by ino 256
1309  */
1310 static inline int is_subvolume_inode(struct inode *inode)
1311 {
1312         if (inode && inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
1313                 return 1;
1314         return 0;
1315 }
1316
1317 static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
1318                                    struct vfsmount *mnt)
1319 {
1320         struct dentry *root;
1321         int ret;
1322
1323         if (!subvol_name) {
1324                 if (!subvol_objectid) {
1325                         ret = get_default_subvol_objectid(btrfs_sb(mnt->mnt_sb),
1326                                                           &subvol_objectid);
1327                         if (ret) {
1328                                 root = ERR_PTR(ret);
1329                                 goto out;
1330                         }
1331                 }
1332                 subvol_name = btrfs_get_subvol_name_from_objectid(
1333                                         btrfs_sb(mnt->mnt_sb), subvol_objectid);
1334                 if (IS_ERR(subvol_name)) {
1335                         root = ERR_CAST(subvol_name);
1336                         subvol_name = NULL;
1337                         goto out;
1338                 }
1339
1340         }
1341
1342         root = mount_subtree(mnt, subvol_name);
1343         /* mount_subtree() drops our reference on the vfsmount. */
1344         mnt = NULL;
1345
1346         if (!IS_ERR(root)) {
1347                 struct super_block *s = root->d_sb;
1348                 struct btrfs_fs_info *fs_info = btrfs_sb(s);
1349                 struct inode *root_inode = d_inode(root);
1350                 u64 root_objectid = BTRFS_I(root_inode)->root->root_key.objectid;
1351
1352                 ret = 0;
1353                 if (!is_subvolume_inode(root_inode)) {
1354                         btrfs_err(fs_info, "'%s' is not a valid subvolume",
1355                                subvol_name);
1356                         ret = -EINVAL;
1357                 }
1358                 if (subvol_objectid && root_objectid != subvol_objectid) {
1359                         /*
1360                          * This will also catch a race condition where a
1361                          * subvolume which was passed by ID is renamed and
1362                          * another subvolume is renamed over the old location.
1363                          */
1364                         btrfs_err(fs_info,
1365                                   "subvol '%s' does not match subvolid %llu",
1366                                   subvol_name, subvol_objectid);
1367                         ret = -EINVAL;
1368                 }
1369                 if (ret) {
1370                         dput(root);
1371                         root = ERR_PTR(ret);
1372                         deactivate_locked_super(s);
1373                 }
1374         }
1375
1376 out:
1377         mntput(mnt);
1378         kfree(subvol_name);
1379         return root;
1380 }
1381
1382 /*
1383  * Find a superblock for the given device / mount point.
1384  *
1385  * Note: This is based on mount_bdev from fs/super.c with a few additions
1386  *       for multiple device setup.  Make sure to keep it in sync.
1387  */
1388 static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
1389                 int flags, const char *device_name, void *data)
1390 {
1391         struct block_device *bdev = NULL;
1392         struct super_block *s;
1393         struct btrfs_device *device = NULL;
1394         struct btrfs_fs_devices *fs_devices = NULL;
1395         struct btrfs_fs_info *fs_info = NULL;
1396         void *new_sec_opts = NULL;
1397         blk_mode_t mode = sb_open_mode(flags);
1398         int error = 0;
1399
1400         if (data) {
1401                 error = security_sb_eat_lsm_opts(data, &new_sec_opts);
1402                 if (error)
1403                         return ERR_PTR(error);
1404         }
1405
1406         /*
1407          * Setup a dummy root and fs_info for test/set super.  This is because
1408          * we don't actually fill this stuff out until open_ctree, but we need
1409          * then open_ctree will properly initialize the file system specific
1410          * settings later.  btrfs_init_fs_info initializes the static elements
1411          * of the fs_info (locks and such) to make cleanup easier if we find a
1412          * superblock with our given fs_devices later on at sget() time.
1413          */
1414         fs_info = kvzalloc(sizeof(struct btrfs_fs_info), GFP_KERNEL);
1415         if (!fs_info) {
1416                 error = -ENOMEM;
1417                 goto error_sec_opts;
1418         }
1419         btrfs_init_fs_info(fs_info);
1420
1421         fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1422         fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
1423         if (!fs_info->super_copy || !fs_info->super_for_commit) {
1424                 error = -ENOMEM;
1425                 goto error_fs_info;
1426         }
1427
1428         mutex_lock(&uuid_mutex);
1429         error = btrfs_parse_device_options(data, mode);
1430         if (error) {
1431                 mutex_unlock(&uuid_mutex);
1432                 goto error_fs_info;
1433         }
1434
1435         /*
1436          * With 'true' passed to btrfs_scan_one_device() (mount time) we expect
1437          * either a valid device or an error.
1438          */
1439         device = btrfs_scan_one_device(device_name, mode, true);
1440         ASSERT(device != NULL);
1441         if (IS_ERR(device)) {
1442                 mutex_unlock(&uuid_mutex);
1443                 error = PTR_ERR(device);
1444                 goto error_fs_info;
1445         }
1446
1447         fs_devices = device->fs_devices;
1448         fs_info->fs_devices = fs_devices;
1449
1450         error = btrfs_open_devices(fs_devices, mode, fs_type);
1451         mutex_unlock(&uuid_mutex);
1452         if (error)
1453                 goto error_fs_info;
1454
1455         if (!(flags & SB_RDONLY) && fs_devices->rw_devices == 0) {
1456                 error = -EACCES;
1457                 goto error_close_devices;
1458         }
1459
1460         bdev = fs_devices->latest_dev->bdev;
1461         s = sget(fs_type, btrfs_test_super, btrfs_set_super, flags | SB_NOSEC,
1462                  fs_info);
1463         if (IS_ERR(s)) {
1464                 error = PTR_ERR(s);
1465                 goto error_close_devices;
1466         }
1467
1468         if (s->s_root) {
1469                 btrfs_close_devices(fs_devices);
1470                 btrfs_free_fs_info(fs_info);
1471                 if ((flags ^ s->s_flags) & SB_RDONLY)
1472                         error = -EBUSY;
1473         } else {
1474                 snprintf(s->s_id, sizeof(s->s_id), "%pg", bdev);
1475                 shrinker_debugfs_rename(&s->s_shrink, "sb-%s:%s", fs_type->name,
1476                                         s->s_id);
1477                 btrfs_sb(s)->bdev_holder = fs_type;
1478                 error = btrfs_fill_super(s, fs_devices, data);
1479         }
1480         if (!error)
1481                 error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL);
1482         security_free_mnt_opts(&new_sec_opts);
1483         if (error) {
1484                 deactivate_locked_super(s);
1485                 return ERR_PTR(error);
1486         }
1487
1488         return dget(s->s_root);
1489
1490 error_close_devices:
1491         btrfs_close_devices(fs_devices);
1492 error_fs_info:
1493         btrfs_free_fs_info(fs_info);
1494 error_sec_opts:
1495         security_free_mnt_opts(&new_sec_opts);
1496         return ERR_PTR(error);
1497 }
1498
1499 /*
1500  * Mount function which is called by VFS layer.
1501  *
1502  * In order to allow mounting a subvolume directly, btrfs uses mount_subtree()
1503  * which needs vfsmount* of device's root (/).  This means device's root has to
1504  * be mounted internally in any case.
1505  *
1506  * Operation flow:
1507  *   1. Parse subvol id related options for later use in mount_subvol().
1508  *
1509  *   2. Mount device's root (/) by calling vfs_kern_mount().
1510  *
1511  *      NOTE: vfs_kern_mount() is used by VFS to call btrfs_mount() in the
1512  *      first place. In order to avoid calling btrfs_mount() again, we use
1513  *      different file_system_type which is not registered to VFS by
1514  *      register_filesystem() (btrfs_root_fs_type). As a result,
1515  *      btrfs_mount_root() is called. The return value will be used by
1516  *      mount_subtree() in mount_subvol().
1517  *
1518  *   3. Call mount_subvol() to get the dentry of subvolume. Since there is
1519  *      "btrfs subvolume set-default", mount_subvol() is called always.
1520  */
1521 static struct dentry *btrfs_mount(struct file_system_type *fs_type, int flags,
1522                 const char *device_name, void *data)
1523 {
1524         struct vfsmount *mnt_root;
1525         struct dentry *root;
1526         char *subvol_name = NULL;
1527         u64 subvol_objectid = 0;
1528         int error = 0;
1529
1530         error = btrfs_parse_subvol_options(data, &subvol_name,
1531                                         &subvol_objectid);
1532         if (error) {
1533                 kfree(subvol_name);
1534                 return ERR_PTR(error);
1535         }
1536
1537         /* mount device's root (/) */
1538         mnt_root = vfs_kern_mount(&btrfs_root_fs_type, flags, device_name, data);
1539         if (PTR_ERR_OR_ZERO(mnt_root) == -EBUSY) {
1540                 if (flags & SB_RDONLY) {
1541                         mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1542                                 flags & ~SB_RDONLY, device_name, data);
1543                 } else {
1544                         mnt_root = vfs_kern_mount(&btrfs_root_fs_type,
1545                                 flags | SB_RDONLY, device_name, data);
1546                         if (IS_ERR(mnt_root)) {
1547                                 root = ERR_CAST(mnt_root);
1548                                 kfree(subvol_name);
1549                                 goto out;
1550                         }
1551
1552                         down_write(&mnt_root->mnt_sb->s_umount);
1553                         error = btrfs_remount(mnt_root->mnt_sb, &flags, NULL);
1554                         up_write(&mnt_root->mnt_sb->s_umount);
1555                         if (error < 0) {
1556                                 root = ERR_PTR(error);
1557                                 mntput(mnt_root);
1558                                 kfree(subvol_name);
1559                                 goto out;
1560                         }
1561                 }
1562         }
1563         if (IS_ERR(mnt_root)) {
1564                 root = ERR_CAST(mnt_root);
1565                 kfree(subvol_name);
1566                 goto out;
1567         }
1568
1569         /* mount_subvol() will free subvol_name and mnt_root */
1570         root = mount_subvol(subvol_name, subvol_objectid, mnt_root);
1571
1572 out:
1573         return root;
1574 }
1575
1576 static void btrfs_resize_thread_pool(struct btrfs_fs_info *fs_info,
1577                                      u32 new_pool_size, u32 old_pool_size)
1578 {
1579         if (new_pool_size == old_pool_size)
1580                 return;
1581
1582         fs_info->thread_pool_size = new_pool_size;
1583
1584         btrfs_info(fs_info, "resize thread pool %d -> %d",
1585                old_pool_size, new_pool_size);
1586
1587         btrfs_workqueue_set_max(fs_info->workers, new_pool_size);
1588         btrfs_workqueue_set_max(fs_info->delalloc_workers, new_pool_size);
1589         btrfs_workqueue_set_max(fs_info->caching_workers, new_pool_size);
1590         workqueue_set_max_active(fs_info->endio_workers, new_pool_size);
1591         workqueue_set_max_active(fs_info->endio_meta_workers, new_pool_size);
1592         btrfs_workqueue_set_max(fs_info->endio_write_workers, new_pool_size);
1593         btrfs_workqueue_set_max(fs_info->endio_freespace_worker, new_pool_size);
1594         btrfs_workqueue_set_max(fs_info->delayed_workers, new_pool_size);
1595 }
1596
1597 static inline void btrfs_remount_begin(struct btrfs_fs_info *fs_info,
1598                                        unsigned long old_opts, int flags)
1599 {
1600         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1601             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) ||
1602              (flags & SB_RDONLY))) {
1603                 /* wait for any defraggers to finish */
1604                 wait_event(fs_info->transaction_wait,
1605                            (atomic_read(&fs_info->defrag_running) == 0));
1606                 if (flags & SB_RDONLY)
1607                         sync_filesystem(fs_info->sb);
1608         }
1609 }
1610
1611 static inline void btrfs_remount_cleanup(struct btrfs_fs_info *fs_info,
1612                                          unsigned long old_opts)
1613 {
1614         const bool cache_opt = btrfs_test_opt(fs_info, SPACE_CACHE);
1615
1616         /*
1617          * We need to cleanup all defragable inodes if the autodefragment is
1618          * close or the filesystem is read only.
1619          */
1620         if (btrfs_raw_test_opt(old_opts, AUTO_DEFRAG) &&
1621             (!btrfs_raw_test_opt(fs_info->mount_opt, AUTO_DEFRAG) || sb_rdonly(fs_info->sb))) {
1622                 btrfs_cleanup_defrag_inodes(fs_info);
1623         }
1624
1625         /* If we toggled discard async */
1626         if (!btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) &&
1627             btrfs_test_opt(fs_info, DISCARD_ASYNC))
1628                 btrfs_discard_resume(fs_info);
1629         else if (btrfs_raw_test_opt(old_opts, DISCARD_ASYNC) &&
1630                  !btrfs_test_opt(fs_info, DISCARD_ASYNC))
1631                 btrfs_discard_cleanup(fs_info);
1632
1633         /* If we toggled space cache */
1634         if (cache_opt != btrfs_free_space_cache_v1_active(fs_info))
1635                 btrfs_set_free_space_cache_v1_active(fs_info, cache_opt);
1636 }
1637
1638 static int btrfs_remount(struct super_block *sb, int *flags, char *data)
1639 {
1640         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
1641         unsigned old_flags = sb->s_flags;
1642         unsigned long old_opts = fs_info->mount_opt;
1643         unsigned long old_compress_type = fs_info->compress_type;
1644         u64 old_max_inline = fs_info->max_inline;
1645         u32 old_thread_pool_size = fs_info->thread_pool_size;
1646         u32 old_metadata_ratio = fs_info->metadata_ratio;
1647         int ret;
1648
1649         sync_filesystem(sb);
1650         set_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1651
1652         if (data) {
1653                 void *new_sec_opts = NULL;
1654
1655                 ret = security_sb_eat_lsm_opts(data, &new_sec_opts);
1656                 if (!ret)
1657                         ret = security_sb_remount(sb, new_sec_opts);
1658                 security_free_mnt_opts(&new_sec_opts);
1659                 if (ret)
1660                         goto restore;
1661         }
1662
1663         ret = btrfs_parse_options(fs_info, data, *flags);
1664         if (ret)
1665                 goto restore;
1666
1667         ret = btrfs_check_features(fs_info, !(*flags & SB_RDONLY));
1668         if (ret < 0)
1669                 goto restore;
1670
1671         btrfs_remount_begin(fs_info, old_opts, *flags);
1672         btrfs_resize_thread_pool(fs_info,
1673                 fs_info->thread_pool_size, old_thread_pool_size);
1674
1675         if ((bool)btrfs_test_opt(fs_info, FREE_SPACE_TREE) !=
1676             (bool)btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE) &&
1677             (!sb_rdonly(sb) || (*flags & SB_RDONLY))) {
1678                 btrfs_warn(fs_info,
1679                 "remount supports changing free space tree only from ro to rw");
1680                 /* Make sure free space cache options match the state on disk */
1681                 if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) {
1682                         btrfs_set_opt(fs_info->mount_opt, FREE_SPACE_TREE);
1683                         btrfs_clear_opt(fs_info->mount_opt, SPACE_CACHE);
1684                 }
1685                 if (btrfs_free_space_cache_v1_active(fs_info)) {
1686                         btrfs_clear_opt(fs_info->mount_opt, FREE_SPACE_TREE);
1687                         btrfs_set_opt(fs_info->mount_opt, SPACE_CACHE);
1688                 }
1689         }
1690
1691         if ((bool)(*flags & SB_RDONLY) == sb_rdonly(sb))
1692                 goto out;
1693
1694         if (*flags & SB_RDONLY) {
1695                 /*
1696                  * this also happens on 'umount -rf' or on shutdown, when
1697                  * the filesystem is busy.
1698                  */
1699                 cancel_work_sync(&fs_info->async_reclaim_work);
1700                 cancel_work_sync(&fs_info->async_data_reclaim_work);
1701
1702                 btrfs_discard_cleanup(fs_info);
1703
1704                 /* wait for the uuid_scan task to finish */
1705                 down(&fs_info->uuid_tree_rescan_sem);
1706                 /* avoid complains from lockdep et al. */
1707                 up(&fs_info->uuid_tree_rescan_sem);
1708
1709                 btrfs_set_sb_rdonly(sb);
1710
1711                 /*
1712                  * Setting SB_RDONLY will put the cleaner thread to
1713                  * sleep at the next loop if it's already active.
1714                  * If it's already asleep, we'll leave unused block
1715                  * groups on disk until we're mounted read-write again
1716                  * unless we clean them up here.
1717                  */
1718                 btrfs_delete_unused_bgs(fs_info);
1719
1720                 /*
1721                  * The cleaner task could be already running before we set the
1722                  * flag BTRFS_FS_STATE_RO (and SB_RDONLY in the superblock).
1723                  * We must make sure that after we finish the remount, i.e. after
1724                  * we call btrfs_commit_super(), the cleaner can no longer start
1725                  * a transaction - either because it was dropping a dead root,
1726                  * running delayed iputs or deleting an unused block group (the
1727                  * cleaner picked a block group from the list of unused block
1728                  * groups before we were able to in the previous call to
1729                  * btrfs_delete_unused_bgs()).
1730                  */
1731                 wait_on_bit(&fs_info->flags, BTRFS_FS_CLEANER_RUNNING,
1732                             TASK_UNINTERRUPTIBLE);
1733
1734                 /*
1735                  * We've set the superblock to RO mode, so we might have made
1736                  * the cleaner task sleep without running all pending delayed
1737                  * iputs. Go through all the delayed iputs here, so that if an
1738                  * unmount happens without remounting RW we don't end up at
1739                  * finishing close_ctree() with a non-empty list of delayed
1740                  * iputs.
1741                  */
1742                 btrfs_run_delayed_iputs(fs_info);
1743
1744                 btrfs_dev_replace_suspend_for_unmount(fs_info);
1745                 btrfs_scrub_cancel(fs_info);
1746                 btrfs_pause_balance(fs_info);
1747
1748                 /*
1749                  * Pause the qgroup rescan worker if it is running. We don't want
1750                  * it to be still running after we are in RO mode, as after that,
1751                  * by the time we unmount, it might have left a transaction open,
1752                  * so we would leak the transaction and/or crash.
1753                  */
1754                 btrfs_qgroup_wait_for_completion(fs_info, false);
1755
1756                 ret = btrfs_commit_super(fs_info);
1757                 if (ret)
1758                         goto restore;
1759         } else {
1760                 if (BTRFS_FS_ERROR(fs_info)) {
1761                         btrfs_err(fs_info,
1762                                 "Remounting read-write after error is not allowed");
1763                         ret = -EINVAL;
1764                         goto restore;
1765                 }
1766                 if (fs_info->fs_devices->rw_devices == 0) {
1767                         ret = -EACCES;
1768                         goto restore;
1769                 }
1770
1771                 if (!btrfs_check_rw_degradable(fs_info, NULL)) {
1772                         btrfs_warn(fs_info,
1773                 "too many missing devices, writable remount is not allowed");
1774                         ret = -EACCES;
1775                         goto restore;
1776                 }
1777
1778                 if (btrfs_super_log_root(fs_info->super_copy) != 0) {
1779                         btrfs_warn(fs_info,
1780                 "mount required to replay tree-log, cannot remount read-write");
1781                         ret = -EINVAL;
1782                         goto restore;
1783                 }
1784
1785                 /*
1786                  * NOTE: when remounting with a change that does writes, don't
1787                  * put it anywhere above this point, as we are not sure to be
1788                  * safe to write until we pass the above checks.
1789                  */
1790                 ret = btrfs_start_pre_rw_mount(fs_info);
1791                 if (ret)
1792                         goto restore;
1793
1794                 btrfs_clear_sb_rdonly(sb);
1795
1796                 set_bit(BTRFS_FS_OPEN, &fs_info->flags);
1797
1798                 /*
1799                  * If we've gone from readonly -> read/write, we need to get
1800                  * our sync/async discard lists in the right state.
1801                  */
1802                 btrfs_discard_resume(fs_info);
1803         }
1804 out:
1805         /*
1806          * We need to set SB_I_VERSION here otherwise it'll get cleared by VFS,
1807          * since the absence of the flag means it can be toggled off by remount.
1808          */
1809         *flags |= SB_I_VERSION;
1810
1811         wake_up_process(fs_info->transaction_kthread);
1812         btrfs_remount_cleanup(fs_info, old_opts);
1813         btrfs_clear_oneshot_options(fs_info);
1814         clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1815
1816         return 0;
1817
1818 restore:
1819         /* We've hit an error - don't reset SB_RDONLY */
1820         if (sb_rdonly(sb))
1821                 old_flags |= SB_RDONLY;
1822         if (!(old_flags & SB_RDONLY))
1823                 clear_bit(BTRFS_FS_STATE_RO, &fs_info->fs_state);
1824         sb->s_flags = old_flags;
1825         fs_info->mount_opt = old_opts;
1826         fs_info->compress_type = old_compress_type;
1827         fs_info->max_inline = old_max_inline;
1828         btrfs_resize_thread_pool(fs_info,
1829                 old_thread_pool_size, fs_info->thread_pool_size);
1830         fs_info->metadata_ratio = old_metadata_ratio;
1831         btrfs_remount_cleanup(fs_info, old_opts);
1832         clear_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state);
1833
1834         return ret;
1835 }
1836
1837 /* Used to sort the devices by max_avail(descending sort) */
1838 static int btrfs_cmp_device_free_bytes(const void *a, const void *b)
1839 {
1840         const struct btrfs_device_info *dev_info1 = a;
1841         const struct btrfs_device_info *dev_info2 = b;
1842
1843         if (dev_info1->max_avail > dev_info2->max_avail)
1844                 return -1;
1845         else if (dev_info1->max_avail < dev_info2->max_avail)
1846                 return 1;
1847         return 0;
1848 }
1849
1850 /*
1851  * sort the devices by max_avail, in which max free extent size of each device
1852  * is stored.(Descending Sort)
1853  */
1854 static inline void btrfs_descending_sort_devices(
1855                                         struct btrfs_device_info *devices,
1856                                         size_t nr_devices)
1857 {
1858         sort(devices, nr_devices, sizeof(struct btrfs_device_info),
1859              btrfs_cmp_device_free_bytes, NULL);
1860 }
1861
1862 /*
1863  * The helper to calc the free space on the devices that can be used to store
1864  * file data.
1865  */
1866 static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info,
1867                                               u64 *free_bytes)
1868 {
1869         struct btrfs_device_info *devices_info;
1870         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
1871         struct btrfs_device *device;
1872         u64 type;
1873         u64 avail_space;
1874         u64 min_stripe_size;
1875         int num_stripes = 1;
1876         int i = 0, nr_devices;
1877         const struct btrfs_raid_attr *rattr;
1878
1879         /*
1880          * We aren't under the device list lock, so this is racy-ish, but good
1881          * enough for our purposes.
1882          */
1883         nr_devices = fs_info->fs_devices->open_devices;
1884         if (!nr_devices) {
1885                 smp_mb();
1886                 nr_devices = fs_info->fs_devices->open_devices;
1887                 ASSERT(nr_devices);
1888                 if (!nr_devices) {
1889                         *free_bytes = 0;
1890                         return 0;
1891                 }
1892         }
1893
1894         devices_info = kmalloc_array(nr_devices, sizeof(*devices_info),
1895                                GFP_KERNEL);
1896         if (!devices_info)
1897                 return -ENOMEM;
1898
1899         /* calc min stripe number for data space allocation */
1900         type = btrfs_data_alloc_profile(fs_info);
1901         rattr = &btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)];
1902
1903         if (type & BTRFS_BLOCK_GROUP_RAID0)
1904                 num_stripes = nr_devices;
1905         else if (type & BTRFS_BLOCK_GROUP_RAID1_MASK)
1906                 num_stripes = rattr->ncopies;
1907         else if (type & BTRFS_BLOCK_GROUP_RAID10)
1908                 num_stripes = 4;
1909
1910         /* Adjust for more than 1 stripe per device */
1911         min_stripe_size = rattr->dev_stripes * BTRFS_STRIPE_LEN;
1912
1913         rcu_read_lock();
1914         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
1915                 if (!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA,
1916                                                 &device->dev_state) ||
1917                     !device->bdev ||
1918                     test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state))
1919                         continue;
1920
1921                 if (i >= nr_devices)
1922                         break;
1923
1924                 avail_space = device->total_bytes - device->bytes_used;
1925
1926                 /* align with stripe_len */
1927                 avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN);
1928
1929                 /*
1930                  * Ensure we have at least min_stripe_size on top of the
1931                  * reserved space on the device.
1932                  */
1933                 if (avail_space <= BTRFS_DEVICE_RANGE_RESERVED + min_stripe_size)
1934                         continue;
1935
1936                 avail_space -= BTRFS_DEVICE_RANGE_RESERVED;
1937
1938                 devices_info[i].dev = device;
1939                 devices_info[i].max_avail = avail_space;
1940
1941                 i++;
1942         }
1943         rcu_read_unlock();
1944
1945         nr_devices = i;
1946
1947         btrfs_descending_sort_devices(devices_info, nr_devices);
1948
1949         i = nr_devices - 1;
1950         avail_space = 0;
1951         while (nr_devices >= rattr->devs_min) {
1952                 num_stripes = min(num_stripes, nr_devices);
1953
1954                 if (devices_info[i].max_avail >= min_stripe_size) {
1955                         int j;
1956                         u64 alloc_size;
1957
1958                         avail_space += devices_info[i].max_avail * num_stripes;
1959                         alloc_size = devices_info[i].max_avail;
1960                         for (j = i + 1 - num_stripes; j <= i; j++)
1961                                 devices_info[j].max_avail -= alloc_size;
1962                 }
1963                 i--;
1964                 nr_devices--;
1965         }
1966
1967         kfree(devices_info);
1968         *free_bytes = avail_space;
1969         return 0;
1970 }
1971
1972 /*
1973  * Calculate numbers for 'df', pessimistic in case of mixed raid profiles.
1974  *
1975  * If there's a redundant raid level at DATA block groups, use the respective
1976  * multiplier to scale the sizes.
1977  *
1978  * Unused device space usage is based on simulating the chunk allocator
1979  * algorithm that respects the device sizes and order of allocations.  This is
1980  * a close approximation of the actual use but there are other factors that may
1981  * change the result (like a new metadata chunk).
1982  *
1983  * If metadata is exhausted, f_bavail will be 0.
1984  */
1985 static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
1986 {
1987         struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
1988         struct btrfs_super_block *disk_super = fs_info->super_copy;
1989         struct btrfs_space_info *found;
1990         u64 total_used = 0;
1991         u64 total_free_data = 0;
1992         u64 total_free_meta = 0;
1993         u32 bits = fs_info->sectorsize_bits;
1994         __be32 *fsid = (__be32 *)fs_info->fs_devices->fsid;
1995         unsigned factor = 1;
1996         struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
1997         int ret;
1998         u64 thresh = 0;
1999         int mixed = 0;
2000
2001         list_for_each_entry(found, &fs_info->space_info, list) {
2002                 if (found->flags & BTRFS_BLOCK_GROUP_DATA) {
2003                         int i;
2004
2005                         total_free_data += found->disk_total - found->disk_used;
2006                         total_free_data -=
2007                                 btrfs_account_ro_block_groups_free_space(found);
2008
2009                         for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) {
2010                                 if (!list_empty(&found->block_groups[i]))
2011                                         factor = btrfs_bg_type_to_factor(
2012                                                 btrfs_raid_array[i].bg_flag);
2013                         }
2014                 }
2015
2016                 /*
2017                  * Metadata in mixed block group profiles are accounted in data
2018                  */
2019                 if (!mixed && found->flags & BTRFS_BLOCK_GROUP_METADATA) {
2020                         if (found->flags & BTRFS_BLOCK_GROUP_DATA)
2021                                 mixed = 1;
2022                         else
2023                                 total_free_meta += found->disk_total -
2024                                         found->disk_used;
2025                 }
2026
2027                 total_used += found->disk_used;
2028         }
2029
2030         buf->f_blocks = div_u64(btrfs_super_total_bytes(disk_super), factor);
2031         buf->f_blocks >>= bits;
2032         buf->f_bfree = buf->f_blocks - (div_u64(total_used, factor) >> bits);
2033
2034         /* Account global block reserve as used, it's in logical size already */
2035         spin_lock(&block_rsv->lock);
2036         /* Mixed block groups accounting is not byte-accurate, avoid overflow */
2037         if (buf->f_bfree >= block_rsv->size >> bits)
2038                 buf->f_bfree -= block_rsv->size >> bits;
2039         else
2040                 buf->f_bfree = 0;
2041         spin_unlock(&block_rsv->lock);
2042
2043         buf->f_bavail = div_u64(total_free_data, factor);
2044         ret = btrfs_calc_avail_data_space(fs_info, &total_free_data);
2045         if (ret)
2046                 return ret;
2047         buf->f_bavail += div_u64(total_free_data, factor);
2048         buf->f_bavail = buf->f_bavail >> bits;
2049
2050         /*
2051          * We calculate the remaining metadata space minus global reserve. If
2052          * this is (supposedly) smaller than zero, there's no space. But this
2053          * does not hold in practice, the exhausted state happens where's still
2054          * some positive delta. So we apply some guesswork and compare the
2055          * delta to a 4M threshold.  (Practically observed delta was ~2M.)
2056          *
2057          * We probably cannot calculate the exact threshold value because this
2058          * depends on the internal reservations requested by various
2059          * operations, so some operations that consume a few metadata will
2060          * succeed even if the Avail is zero. But this is better than the other
2061          * way around.
2062          */
2063         thresh = SZ_4M;
2064
2065         /*
2066          * We only want to claim there's no available space if we can no longer
2067          * allocate chunks for our metadata profile and our global reserve will
2068          * not fit in the free metadata space.  If we aren't ->full then we
2069          * still can allocate chunks and thus are fine using the currently
2070          * calculated f_bavail.
2071          */
2072         if (!mixed && block_rsv->space_info->full &&
2073             (total_free_meta < thresh || total_free_meta - thresh < block_rsv->size))
2074                 buf->f_bavail = 0;
2075
2076         buf->f_type = BTRFS_SUPER_MAGIC;
2077         buf->f_bsize = dentry->d_sb->s_blocksize;
2078         buf->f_namelen = BTRFS_NAME_LEN;
2079
2080         /* We treat it as constant endianness (it doesn't matter _which_)
2081            because we want the fsid to come out the same whether mounted
2082            on a big-endian or little-endian host */
2083         buf->f_fsid.val[0] = be32_to_cpu(fsid[0]) ^ be32_to_cpu(fsid[2]);
2084         buf->f_fsid.val[1] = be32_to_cpu(fsid[1]) ^ be32_to_cpu(fsid[3]);
2085         /* Mask in the root object ID too, to disambiguate subvols */
2086         buf->f_fsid.val[0] ^=
2087                 BTRFS_I(d_inode(dentry))->root->root_key.objectid >> 32;
2088         buf->f_fsid.val[1] ^=
2089                 BTRFS_I(d_inode(dentry))->root->root_key.objectid;
2090
2091         return 0;
2092 }
2093
2094 static void btrfs_kill_super(struct super_block *sb)
2095 {
2096         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2097         kill_anon_super(sb);
2098         btrfs_free_fs_info(fs_info);
2099 }
2100
2101 static struct file_system_type btrfs_fs_type = {
2102         .owner          = THIS_MODULE,
2103         .name           = "btrfs",
2104         .mount          = btrfs_mount,
2105         .kill_sb        = btrfs_kill_super,
2106         .fs_flags       = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
2107 };
2108
2109 static struct file_system_type btrfs_root_fs_type = {
2110         .owner          = THIS_MODULE,
2111         .name           = "btrfs",
2112         .mount          = btrfs_mount_root,
2113         .kill_sb        = btrfs_kill_super,
2114         .fs_flags       = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_ALLOW_IDMAP,
2115 };
2116
2117 MODULE_ALIAS_FS("btrfs");
2118
2119 static int btrfs_control_open(struct inode *inode, struct file *file)
2120 {
2121         /*
2122          * The control file's private_data is used to hold the
2123          * transaction when it is started and is used to keep
2124          * track of whether a transaction is already in progress.
2125          */
2126         file->private_data = NULL;
2127         return 0;
2128 }
2129
2130 /*
2131  * Used by /dev/btrfs-control for devices ioctls.
2132  */
2133 static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
2134                                 unsigned long arg)
2135 {
2136         struct btrfs_ioctl_vol_args *vol;
2137         struct btrfs_device *device = NULL;
2138         dev_t devt = 0;
2139         int ret = -ENOTTY;
2140
2141         if (!capable(CAP_SYS_ADMIN))
2142                 return -EPERM;
2143
2144         vol = memdup_user((void __user *)arg, sizeof(*vol));
2145         if (IS_ERR(vol))
2146                 return PTR_ERR(vol);
2147         vol->name[BTRFS_PATH_NAME_MAX] = '\0';
2148
2149         switch (cmd) {
2150         case BTRFS_IOC_SCAN_DEV:
2151                 mutex_lock(&uuid_mutex);
2152                 /*
2153                  * Scanning outside of mount can return NULL which would turn
2154                  * into 0 error code.
2155                  */
2156                 device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ, false);
2157                 ret = PTR_ERR_OR_ZERO(device);
2158                 mutex_unlock(&uuid_mutex);
2159                 break;
2160         case BTRFS_IOC_FORGET_DEV:
2161                 if (vol->name[0] != 0) {
2162                         ret = lookup_bdev(vol->name, &devt);
2163                         if (ret)
2164                                 break;
2165                 }
2166                 ret = btrfs_forget_devices(devt);
2167                 break;
2168         case BTRFS_IOC_DEVICES_READY:
2169                 mutex_lock(&uuid_mutex);
2170                 /*
2171                  * Scanning outside of mount can return NULL which would turn
2172                  * into 0 error code.
2173                  */
2174                 device = btrfs_scan_one_device(vol->name, BLK_OPEN_READ, false);
2175                 if (IS_ERR_OR_NULL(device)) {
2176                         mutex_unlock(&uuid_mutex);
2177                         ret = PTR_ERR(device);
2178                         break;
2179                 }
2180                 ret = !(device->fs_devices->num_devices ==
2181                         device->fs_devices->total_devices);
2182                 mutex_unlock(&uuid_mutex);
2183                 break;
2184         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
2185                 ret = btrfs_ioctl_get_supported_features((void __user*)arg);
2186                 break;
2187         }
2188
2189         kfree(vol);
2190         return ret;
2191 }
2192
2193 static int btrfs_freeze(struct super_block *sb)
2194 {
2195         struct btrfs_trans_handle *trans;
2196         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2197         struct btrfs_root *root = fs_info->tree_root;
2198
2199         set_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2200         /*
2201          * We don't need a barrier here, we'll wait for any transaction that
2202          * could be in progress on other threads (and do delayed iputs that
2203          * we want to avoid on a frozen filesystem), or do the commit
2204          * ourselves.
2205          */
2206         trans = btrfs_attach_transaction_barrier(root);
2207         if (IS_ERR(trans)) {
2208                 /* no transaction, don't bother */
2209                 if (PTR_ERR(trans) == -ENOENT)
2210                         return 0;
2211                 return PTR_ERR(trans);
2212         }
2213         return btrfs_commit_transaction(trans);
2214 }
2215
2216 static int check_dev_super(struct btrfs_device *dev)
2217 {
2218         struct btrfs_fs_info *fs_info = dev->fs_info;
2219         struct btrfs_super_block *sb;
2220         u64 last_trans;
2221         u16 csum_type;
2222         int ret = 0;
2223
2224         /* This should be called with fs still frozen. */
2225         ASSERT(test_bit(BTRFS_FS_FROZEN, &fs_info->flags));
2226
2227         /* Missing dev, no need to check. */
2228         if (!dev->bdev)
2229                 return 0;
2230
2231         /* Only need to check the primary super block. */
2232         sb = btrfs_read_dev_one_super(dev->bdev, 0, true);
2233         if (IS_ERR(sb))
2234                 return PTR_ERR(sb);
2235
2236         /* Verify the checksum. */
2237         csum_type = btrfs_super_csum_type(sb);
2238         if (csum_type != btrfs_super_csum_type(fs_info->super_copy)) {
2239                 btrfs_err(fs_info, "csum type changed, has %u expect %u",
2240                           csum_type, btrfs_super_csum_type(fs_info->super_copy));
2241                 ret = -EUCLEAN;
2242                 goto out;
2243         }
2244
2245         if (btrfs_check_super_csum(fs_info, sb)) {
2246                 btrfs_err(fs_info, "csum for on-disk super block no longer matches");
2247                 ret = -EUCLEAN;
2248                 goto out;
2249         }
2250
2251         /* Btrfs_validate_super() includes fsid check against super->fsid. */
2252         ret = btrfs_validate_super(fs_info, sb, 0);
2253         if (ret < 0)
2254                 goto out;
2255
2256         last_trans = btrfs_get_last_trans_committed(fs_info);
2257         if (btrfs_super_generation(sb) != last_trans) {
2258                 btrfs_err(fs_info, "transid mismatch, has %llu expect %llu",
2259                           btrfs_super_generation(sb), last_trans);
2260                 ret = -EUCLEAN;
2261                 goto out;
2262         }
2263 out:
2264         btrfs_release_disk_super(sb);
2265         return ret;
2266 }
2267
2268 static int btrfs_unfreeze(struct super_block *sb)
2269 {
2270         struct btrfs_fs_info *fs_info = btrfs_sb(sb);
2271         struct btrfs_device *device;
2272         int ret = 0;
2273
2274         /*
2275          * Make sure the fs is not changed by accident (like hibernation then
2276          * modified by other OS).
2277          * If we found anything wrong, we mark the fs error immediately.
2278          *
2279          * And since the fs is frozen, no one can modify the fs yet, thus
2280          * we don't need to hold device_list_mutex.
2281          */
2282         list_for_each_entry(device, &fs_info->fs_devices->devices, dev_list) {
2283                 ret = check_dev_super(device);
2284                 if (ret < 0) {
2285                         btrfs_handle_fs_error(fs_info, ret,
2286                                 "super block on devid %llu got modified unexpectedly",
2287                                 device->devid);
2288                         break;
2289                 }
2290         }
2291         clear_bit(BTRFS_FS_FROZEN, &fs_info->flags);
2292
2293         /*
2294          * We still return 0, to allow VFS layer to unfreeze the fs even the
2295          * above checks failed. Since the fs is either fine or read-only, we're
2296          * safe to continue, without causing further damage.
2297          */
2298         return 0;
2299 }
2300
2301 static int btrfs_show_devname(struct seq_file *m, struct dentry *root)
2302 {
2303         struct btrfs_fs_info *fs_info = btrfs_sb(root->d_sb);
2304
2305         /*
2306          * There should be always a valid pointer in latest_dev, it may be stale
2307          * for a short moment in case it's being deleted but still valid until
2308          * the end of RCU grace period.
2309          */
2310         rcu_read_lock();
2311         seq_escape(m, btrfs_dev_name(fs_info->fs_devices->latest_dev), " \t\n\\");
2312         rcu_read_unlock();
2313
2314         return 0;
2315 }
2316
2317 static const struct super_operations btrfs_super_ops = {
2318         .drop_inode     = btrfs_drop_inode,
2319         .evict_inode    = btrfs_evict_inode,
2320         .put_super      = btrfs_put_super,
2321         .sync_fs        = btrfs_sync_fs,
2322         .show_options   = btrfs_show_options,
2323         .show_devname   = btrfs_show_devname,
2324         .alloc_inode    = btrfs_alloc_inode,
2325         .destroy_inode  = btrfs_destroy_inode,
2326         .free_inode     = btrfs_free_inode,
2327         .statfs         = btrfs_statfs,
2328         .remount_fs     = btrfs_remount,
2329         .freeze_fs      = btrfs_freeze,
2330         .unfreeze_fs    = btrfs_unfreeze,
2331 };
2332
2333 static const struct file_operations btrfs_ctl_fops = {
2334         .open = btrfs_control_open,
2335         .unlocked_ioctl  = btrfs_control_ioctl,
2336         .compat_ioctl = compat_ptr_ioctl,
2337         .owner   = THIS_MODULE,
2338         .llseek = noop_llseek,
2339 };
2340
2341 static struct miscdevice btrfs_misc = {
2342         .minor          = BTRFS_MINOR,
2343         .name           = "btrfs-control",
2344         .fops           = &btrfs_ctl_fops
2345 };
2346
2347 MODULE_ALIAS_MISCDEV(BTRFS_MINOR);
2348 MODULE_ALIAS("devname:btrfs-control");
2349
2350 static int __init btrfs_interface_init(void)
2351 {
2352         return misc_register(&btrfs_misc);
2353 }
2354
2355 static __cold void btrfs_interface_exit(void)
2356 {
2357         misc_deregister(&btrfs_misc);
2358 }
2359
2360 static int __init btrfs_print_mod_info(void)
2361 {
2362         static const char options[] = ""
2363 #ifdef CONFIG_BTRFS_DEBUG
2364                         ", debug=on"
2365 #endif
2366 #ifdef CONFIG_BTRFS_ASSERT
2367                         ", assert=on"
2368 #endif
2369 #ifdef CONFIG_BTRFS_FS_REF_VERIFY
2370                         ", ref-verify=on"
2371 #endif
2372 #ifdef CONFIG_BLK_DEV_ZONED
2373                         ", zoned=yes"
2374 #else
2375                         ", zoned=no"
2376 #endif
2377 #ifdef CONFIG_FS_VERITY
2378                         ", fsverity=yes"
2379 #else
2380                         ", fsverity=no"
2381 #endif
2382                         ;
2383         pr_info("Btrfs loaded%s\n", options);
2384         return 0;
2385 }
2386
2387 static int register_btrfs(void)
2388 {
2389         return register_filesystem(&btrfs_fs_type);
2390 }
2391
2392 static void unregister_btrfs(void)
2393 {
2394         unregister_filesystem(&btrfs_fs_type);
2395 }
2396
2397 /* Helper structure for long init/exit functions. */
2398 struct init_sequence {
2399         int (*init_func)(void);
2400         /* Can be NULL if the init_func doesn't need cleanup. */
2401         void (*exit_func)(void);
2402 };
2403
2404 static const struct init_sequence mod_init_seq[] = {
2405         {
2406                 .init_func = btrfs_props_init,
2407                 .exit_func = NULL,
2408         }, {
2409                 .init_func = btrfs_init_sysfs,
2410                 .exit_func = btrfs_exit_sysfs,
2411         }, {
2412                 .init_func = btrfs_init_compress,
2413                 .exit_func = btrfs_exit_compress,
2414         }, {
2415                 .init_func = btrfs_init_cachep,
2416                 .exit_func = btrfs_destroy_cachep,
2417         }, {
2418                 .init_func = btrfs_transaction_init,
2419                 .exit_func = btrfs_transaction_exit,
2420         }, {
2421                 .init_func = btrfs_ctree_init,
2422                 .exit_func = btrfs_ctree_exit,
2423         }, {
2424                 .init_func = btrfs_free_space_init,
2425                 .exit_func = btrfs_free_space_exit,
2426         }, {
2427                 .init_func = extent_state_init_cachep,
2428                 .exit_func = extent_state_free_cachep,
2429         }, {
2430                 .init_func = extent_buffer_init_cachep,
2431                 .exit_func = extent_buffer_free_cachep,
2432         }, {
2433                 .init_func = btrfs_bioset_init,
2434                 .exit_func = btrfs_bioset_exit,
2435         }, {
2436                 .init_func = extent_map_init,
2437                 .exit_func = extent_map_exit,
2438         }, {
2439                 .init_func = ordered_data_init,
2440                 .exit_func = ordered_data_exit,
2441         }, {
2442                 .init_func = btrfs_delayed_inode_init,
2443                 .exit_func = btrfs_delayed_inode_exit,
2444         }, {
2445                 .init_func = btrfs_auto_defrag_init,
2446                 .exit_func = btrfs_auto_defrag_exit,
2447         }, {
2448                 .init_func = btrfs_delayed_ref_init,
2449                 .exit_func = btrfs_delayed_ref_exit,
2450         }, {
2451                 .init_func = btrfs_prelim_ref_init,
2452                 .exit_func = btrfs_prelim_ref_exit,
2453         }, {
2454                 .init_func = btrfs_interface_init,
2455                 .exit_func = btrfs_interface_exit,
2456         }, {
2457                 .init_func = btrfs_print_mod_info,
2458                 .exit_func = NULL,
2459         }, {
2460                 .init_func = btrfs_run_sanity_tests,
2461                 .exit_func = NULL,
2462         }, {
2463                 .init_func = register_btrfs,
2464                 .exit_func = unregister_btrfs,
2465         }
2466 };
2467
2468 static bool mod_init_result[ARRAY_SIZE(mod_init_seq)];
2469
2470 static __always_inline void btrfs_exit_btrfs_fs(void)
2471 {
2472         int i;
2473
2474         for (i = ARRAY_SIZE(mod_init_seq) - 1; i >= 0; i--) {
2475                 if (!mod_init_result[i])
2476                         continue;
2477                 if (mod_init_seq[i].exit_func)
2478                         mod_init_seq[i].exit_func();
2479                 mod_init_result[i] = false;
2480         }
2481 }
2482
2483 static void __exit exit_btrfs_fs(void)
2484 {
2485         btrfs_exit_btrfs_fs();
2486         btrfs_cleanup_fs_uuids();
2487 }
2488
2489 static int __init init_btrfs_fs(void)
2490 {
2491         int ret;
2492         int i;
2493
2494         for (i = 0; i < ARRAY_SIZE(mod_init_seq); i++) {
2495                 ASSERT(!mod_init_result[i]);
2496                 ret = mod_init_seq[i].init_func();
2497                 if (ret < 0) {
2498                         btrfs_exit_btrfs_fs();
2499                         return ret;
2500                 }
2501                 mod_init_result[i] = true;
2502         }
2503         return 0;
2504 }
2505
2506 late_initcall(init_btrfs_fs);
2507 module_exit(exit_btrfs_fs)
2508
2509 MODULE_LICENSE("GPL");
2510 MODULE_SOFTDEP("pre: crc32c");
2511 MODULE_SOFTDEP("pre: xxhash64");
2512 MODULE_SOFTDEP("pre: sha256");
2513 MODULE_SOFTDEP("pre: blake2b-256");