fs/xfs/scrub/scrub.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2017 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_trans_resv.h"
  11 #include "xfs_mount.h"
  12 #include "xfs_defer.h"
  13 #include "xfs_btree.h"
  14 #include "xfs_bit.h"
  15 #include "xfs_log_format.h"
  16 #include "xfs_trans.h"
  17 #include "xfs_sb.h"
  18 #include "xfs_inode.h"
  19 #include "xfs_icache.h"
  20 #include "xfs_itable.h"
  21 #include "xfs_alloc.h"
  22 #include "xfs_alloc_btree.h"
  23 #include "xfs_bmap.h"
  24 #include "xfs_bmap_btree.h"
  25 #include "xfs_ialloc.h"
  26 #include "xfs_ialloc_btree.h"
  27 #include "xfs_refcount.h"
  28 #include "xfs_refcount_btree.h"
  29 #include "xfs_rmap.h"
  30 #include "xfs_rmap_btree.h"
  31 #include "xfs_quota.h"
  32 #include "xfs_qm.h"
  33 #include "xfs_errortag.h"
  34 #include "xfs_error.h"
  35 #include "xfs_log.h"
  36 #include "xfs_trans_priv.h"
  37 #include "scrub/xfs_scrub.h"
  38 #include "scrub/scrub.h"
  39 #include "scrub/common.h"
  40 #include "scrub/trace.h"
  41 #include "scrub/btree.h"
  42 #include "scrub/repair.h"
  43
  44 /*
  45  * Online Scrub and Repair
  46  *
  47  * Traditionally, XFS (the kernel driver) did not know how to check or
  48  * repair on-disk data structures.  That task was left to the xfs_check
  49  * and xfs_repair tools, both of which require taking the filesystem
  50  * offline for a thorough but time consuming examination.  Online
  51  * scrub & repair, on the other hand, enables us to check the metadata
  52  * for obvious errors while carefully stepping around the filesystem's
  53  * ongoing operations, locking rules, etc.
  54  *
  55  * Given that most XFS metadata consist of records stored in a btree,
  56  * most of the checking functions iterate the btree blocks themselves
  57  * looking for irregularities.  When a record block is encountered, each
  58  * record can be checked for obviously bad values.  Record values can
  59  * also be cross-referenced against other btrees to look for potential
  60  * misunderstandings between pieces of metadata.
  61  *
  62  * It is expected that the checkers responsible for per-AG metadata
  63  * structures will lock the AG headers (AGI, AGF, AGFL), iterate the
  64  * metadata structure, and perform any relevant cross-referencing before
  65  * unlocking the AG and returning the results to userspace.  These
  66  * scrubbers must not keep an AG locked for too long to avoid tying up
  67  * the block and inode allocators.
  68  *
  69  * Block maps and b-trees rooted in an inode present a special challenge
  70  * because they can involve extents from any AG.  The general scrubber
  71  * structure of lock -> check -> xref -> unlock still holds, but AG
  72  * locking order rules /must/ be obeyed to avoid deadlocks.  The
  73  * ordering rule, of course, is that we must lock in increasing AG
  74  * order.  Helper functions are provided to track which AG headers we've
  75  * already locked.  If we detect an imminent locking order violation, we
  76  * can signal a potential deadlock, in which case the scrubber can jump
  77  * out to the top level, lock all the AGs in order, and retry the scrub.
  78  *
  79  * For file data (directories, extended attributes, symlinks) scrub, we
  80  * can simply lock the inode and walk the data.  For btree data
  81  * (directories and attributes) we follow the same btree-scrubbing
  82  * strategy outlined previously to check the records.
  83  *
  84  * We use a bit of trickery with transactions to avoid buffer deadlocks
  85  * if there is a cycle in the metadata.  The basic problem is that
  86  * travelling down a btree involves locking the current buffer at each
  87  * tree level.  If a pointer should somehow point back to a buffer that
  88  * we've already examined, we will deadlock due to the second buffer
  89  * locking attempt.  Note however that grabbing a buffer in transaction
  90  * context links the locked buffer to the transaction.  If we try to
  91  * re-grab the buffer in the context of the same transaction, we avoid
  92  * the second lock attempt and continue.  Between the verifier and the
  93  * scrubber, something will notice that something is amiss and report
  94  * the corruption.  Therefore, each scrubber will allocate an empty
  95  * transaction, attach buffers to it, and cancel the transaction at the
  96  * end of the scrub run.  Cancelling a non-dirty transaction simply
  97  * unlocks the buffers.
  98  *
  99  * There are four pieces of data that scrub can communicate to
 100  * userspace.  The first is the error code (errno), which can be used to
 101  * communicate operational errors in performing the scrub.  There are
 102  * also three flags that can be set in the scrub context.  If the data
 103  * structure itself is corrupt, the CORRUPT flag will be set.  If
 104  * the metadata is correct but otherwise suboptimal, the PREEN flag
 105  * will be set.
 106  *
 107  * We perform secondary validation of filesystem metadata by
 108  * cross-referencing every record with all other available metadata.
 109  * For example, for block mapping extents, we verify that there are no
 110  * records in the free space and inode btrees corresponding to that
 111  * space extent and that there is a corresponding entry in the reverse
 112  * mapping btree.  Inconsistent metadata is noted by setting the
 113  * XCORRUPT flag; btree query function errors are noted by setting the
 114  * XFAIL flag and deleting the cursor to prevent further attempts to
 115  * cross-reference with a defective btree.
 116  *
 117  * If a piece of metadata proves corrupt or suboptimal, the userspace
 118  * program can ask the kernel to apply some tender loving care (TLC) to
 119  * the metadata object by setting the REPAIR flag and re-calling the
 120  * scrub ioctl.  "Corruption" is defined by metadata violating the
 121  * on-disk specification; operations cannot continue if the violation is
 122  * left untreated.  It is possible for XFS to continue if an object is
 123  * "suboptimal", however performance may be degraded.  Repairs are
 124  * usually performed by rebuilding the metadata entirely out of
 125  * redundant metadata.  Optimizing, on the other hand, can sometimes be
 126  * done without rebuilding entire structures.
 127  *
 128  * Generally speaking, the repair code has the following code structure:
 129  * Lock -> scrub -> repair -> commit -> re-lock -> re-scrub -> unlock.
 130  * The first check helps us figure out if we need to rebuild or simply
 131  * optimize the structure so that the rebuild knows what to do.  The
 132  * second check evaluates the completeness of the repair; that is what
 133  * is reported to userspace.
 134  *
 135  * A quick note on symbol prefixes:
 136  * - "xfs_" are general XFS symbols.
 137  * - "xchk_" are symbols related to metadata checking.
 138  * - "xrep_" are symbols related to metadata repair.
 139  * - "xfs_scrub_" are symbols that tie online fsck to the rest of XFS.
 140  */
 141
 142 /*
 143  * Scrub probe -- userspace uses this to probe if we're willing to scrub
 144  * or repair a given mountpoint.  This will be used by xfs_scrub to
 145  * probe the kernel's abilities to scrub (and repair) the metadata.  We
 146  * do this by validating the ioctl inputs from userspace, preparing the
 147  * filesystem for a scrub (or a repair) operation, and immediately
 148  * returning to userspace.  Userspace can use the returned errno and
 149  * structure state to decide (in broad terms) if scrub/repair are
 150  * supported by the running kernel.
 151  */
 152 static int
 153 xchk_probe(
 154         struct xfs_scrub        *sc)
 155 {
 156         int                     error = 0;
 157
 158         if (xchk_should_terminate(sc, &error))
 159                 return error;
 160
 161         return 0;
 162 }
 163
 164 /* Scrub setup and teardown */
 165
 166 /* Free all the resources and finish the transactions. */
 167 STATIC int
 168 xchk_teardown(
 169         struct xfs_scrub        *sc,
 170         struct xfs_inode        *ip_in,
 171         int                     error)
 172 {
 173         xchk_ag_free(sc, &sc->sa);
 174         if (sc->tp) {
 175                 if (error == 0 && (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR))
 176                         error = xfs_trans_commit(sc->tp);
 177                 else
 178                         xfs_trans_cancel(sc->tp);
 179                 sc->tp = NULL;
 180         }
 181         if (sc->ip) {
 182                 if (sc->ilock_flags)
 183                         xfs_iunlock(sc->ip, sc->ilock_flags);
 184                 if (sc->ip != ip_in &&
 185                     !xfs_internal_inum(sc->mp, sc->ip->i_ino))
 186                         xfs_irele(sc->ip);
 187                 sc->ip = NULL;
 188         }
 189         if (sc->has_quotaofflock)
 190                 mutex_unlock(&sc->mp->m_quotainfo->qi_quotaofflock);
 191         if (sc->buf) {
 192                 kmem_free(sc->buf);
 193                 sc->buf = NULL;
 194         }
 195         return error;
 196 }
 197
 198 /* Scrubbing dispatch. */
 199
 200 static const struct xchk_meta_ops meta_scrub_ops[] = {
 201         [XFS_SCRUB_TYPE_PROBE] = {      /* ioctl presence test */
 202                 .type   = ST_NONE,
 203                 .setup  = xchk_setup_fs,
 204                 .scrub  = xchk_probe,
 205                 .repair = xrep_probe,
 206         },
 207         [XFS_SCRUB_TYPE_SB] = {         /* superblock */
 208                 .type   = ST_PERAG,
 209                 .setup  = xchk_setup_fs,
 210                 .scrub  = xchk_superblock,
 211                 .repair = xrep_superblock,
 212         },
 213         [XFS_SCRUB_TYPE_AGF] = {        /* agf */
 214                 .type   = ST_PERAG,
 215                 .setup  = xchk_setup_fs,
 216                 .scrub  = xchk_agf,
 217                 .repair = xrep_agf,
 218         },
 219         [XFS_SCRUB_TYPE_AGFL]= {        /* agfl */
 220                 .type   = ST_PERAG,
 221                 .setup  = xchk_setup_fs,
 222                 .scrub  = xchk_agfl,
 223                 .repair = xrep_agfl,
 224         },
 225         [XFS_SCRUB_TYPE_AGI] = {        /* agi */
 226                 .type   = ST_PERAG,
 227                 .setup  = xchk_setup_fs,
 228                 .scrub  = xchk_agi,
 229                 .repair = xrep_agi,
 230         },
 231         [XFS_SCRUB_TYPE_BNOBT] = {      /* bnobt */
 232                 .type   = ST_PERAG,
 233                 .setup  = xchk_setup_ag_allocbt,
 234                 .scrub  = xchk_bnobt,
 235                 .repair = xrep_notsupported,
 236         },
 237         [XFS_SCRUB_TYPE_CNTBT] = {      /* cntbt */
 238                 .type   = ST_PERAG,
 239                 .setup  = xchk_setup_ag_allocbt,
 240                 .scrub  = xchk_cntbt,
 241                 .repair = xrep_notsupported,
 242         },
 243         [XFS_SCRUB_TYPE_INOBT] = {      /* inobt */
 244                 .type   = ST_PERAG,
 245                 .setup  = xchk_setup_ag_iallocbt,
 246                 .scrub  = xchk_inobt,
 247                 .repair = xrep_notsupported,
 248         },
 249         [XFS_SCRUB_TYPE_FINOBT] = {     /* finobt */
 250                 .type   = ST_PERAG,
 251                 .setup  = xchk_setup_ag_iallocbt,
 252                 .scrub  = xchk_finobt,
 253                 .has    = xfs_sb_version_hasfinobt,
 254                 .repair = xrep_notsupported,
 255         },
 256         [XFS_SCRUB_TYPE_RMAPBT] = {     /* rmapbt */
 257                 .type   = ST_PERAG,
 258                 .setup  = xchk_setup_ag_rmapbt,
 259                 .scrub  = xchk_rmapbt,
 260                 .has    = xfs_sb_version_hasrmapbt,
 261                 .repair = xrep_notsupported,
 262         },
 263         [XFS_SCRUB_TYPE_REFCNTBT] = {   /* refcountbt */
 264                 .type   = ST_PERAG,
 265                 .setup  = xchk_setup_ag_refcountbt,
 266                 .scrub  = xchk_refcountbt,
 267                 .has    = xfs_sb_version_hasreflink,
 268                 .repair = xrep_notsupported,
 269         },
 270         [XFS_SCRUB_TYPE_INODE] = {      /* inode record */
 271                 .type   = ST_INODE,
 272                 .setup  = xchk_setup_inode,
 273                 .scrub  = xchk_inode,
 274                 .repair = xrep_notsupported,
 275         },
 276         [XFS_SCRUB_TYPE_BMBTD] = {      /* inode data fork */
 277                 .type   = ST_INODE,
 278                 .setup  = xchk_setup_inode_bmap,
 279                 .scrub  = xchk_bmap_data,
 280                 .repair = xrep_notsupported,
 281         },
 282         [XFS_SCRUB_TYPE_BMBTA] = {      /* inode attr fork */
 283                 .type   = ST_INODE,
 284                 .setup  = xchk_setup_inode_bmap,
 285                 .scrub  = xchk_bmap_attr,
 286                 .repair = xrep_notsupported,
 287         },
 288         [XFS_SCRUB_TYPE_BMBTC] = {      /* inode CoW fork */
 289                 .type   = ST_INODE,
 290                 .setup  = xchk_setup_inode_bmap,
 291                 .scrub  = xchk_bmap_cow,
 292                 .repair = xrep_notsupported,
 293         },
 294         [XFS_SCRUB_TYPE_DIR] = {        /* directory */
 295                 .type   = ST_INODE,
 296                 .setup  = xchk_setup_directory,
 297                 .scrub  = xchk_directory,
 298                 .repair = xrep_notsupported,
 299         },
 300         [XFS_SCRUB_TYPE_XATTR] = {      /* extended attributes */
 301                 .type   = ST_INODE,
 302                 .setup  = xchk_setup_xattr,
 303                 .scrub  = xchk_xattr,
 304                 .repair = xrep_notsupported,
 305         },
 306         [XFS_SCRUB_TYPE_SYMLINK] = {    /* symbolic link */
 307                 .type   = ST_INODE,
 308                 .setup  = xchk_setup_symlink,
 309                 .scrub  = xchk_symlink,
 310                 .repair = xrep_notsupported,
 311         },
 312         [XFS_SCRUB_TYPE_PARENT] = {     /* parent pointers */
 313                 .type   = ST_INODE,
 314                 .setup  = xchk_setup_parent,
 315                 .scrub  = xchk_parent,
 316                 .repair = xrep_notsupported,
 317         },
 318         [XFS_SCRUB_TYPE_RTBITMAP] = {   /* realtime bitmap */
 319                 .type   = ST_FS,
 320                 .setup  = xchk_setup_rt,
 321                 .scrub  = xchk_rtbitmap,
 322                 .has    = xfs_sb_version_hasrealtime,
 323                 .repair = xrep_notsupported,
 324         },
 325         [XFS_SCRUB_TYPE_RTSUM] = {      /* realtime summary */
 326                 .type   = ST_FS,
 327                 .setup  = xchk_setup_rt,
 328                 .scrub  = xchk_rtsummary,
 329                 .has    = xfs_sb_version_hasrealtime,
 330                 .repair = xrep_notsupported,
 331         },
 332         [XFS_SCRUB_TYPE_UQUOTA] = {     /* user quota */
 333                 .type   = ST_FS,
 334                 .setup  = xchk_setup_quota,
 335                 .scrub  = xchk_quota,
 336                 .repair = xrep_notsupported,
 337         },
 338         [XFS_SCRUB_TYPE_GQUOTA] = {     /* group quota */
 339                 .type   = ST_FS,
 340                 .setup  = xchk_setup_quota,
 341                 .scrub  = xchk_quota,
 342                 .repair = xrep_notsupported,
 343         },
 344         [XFS_SCRUB_TYPE_PQUOTA] = {     /* project quota */
 345                 .type   = ST_FS,
 346                 .setup  = xchk_setup_quota,
 347                 .scrub  = xchk_quota,
 348                 .repair = xrep_notsupported,
 349         },
 350 };
 351
 352 /* This isn't a stable feature, warn once per day. */
 353 static inline void
 354 xchk_experimental_warning(
 355         struct xfs_mount        *mp)
 356 {
 357         static struct ratelimit_state scrub_warning = RATELIMIT_STATE_INIT(
 358                         "xchk_warning", 86400 * HZ, 1);
 359         ratelimit_set_flags(&scrub_warning, RATELIMIT_MSG_ON_RELEASE);
 360
 361         if (__ratelimit(&scrub_warning))
 362                 xfs_alert(mp,
 363 "EXPERIMENTAL online scrub feature in use. Use at your own risk!");
 364 }
 365
 366 static int
 367 xchk_validate_inputs(
 368         struct xfs_mount                *mp,
 369         struct xfs_scrub_metadata       *sm)
 370 {
 371         int                             error;
 372         const struct xchk_meta_ops      *ops;
 373
 374         error = -EINVAL;
 375         /* Check our inputs. */
 376         sm->sm_flags &= ~XFS_SCRUB_FLAGS_OUT;
 377         if (sm->sm_flags & ~XFS_SCRUB_FLAGS_IN)
 378                 goto out;
 379         /* sm_reserved[] must be zero */
 380         if (memchr_inv(sm->sm_reserved, 0, sizeof(sm->sm_reserved)))
 381                 goto out;
 382
 383         error = -ENOENT;
 384         /* Do we know about this type of metadata? */
 385         if (sm->sm_type >= XFS_SCRUB_TYPE_NR)
 386                 goto out;
 387         ops = &meta_scrub_ops[sm->sm_type];
 388         if (ops->setup == NULL || ops->scrub == NULL)
 389                 goto out;
 390         /* Does this fs even support this type of metadata? */
 391         if (ops->has && !ops->has(&mp->m_sb))
 392                 goto out;
 393
 394         error = -EINVAL;
 395         /* restricting fields must be appropriate for type */
 396         switch (ops->type) {
 397         case ST_NONE:
 398         case ST_FS:
 399                 if (sm->sm_ino || sm->sm_gen || sm->sm_agno)
 400                         goto out;
 401                 break;
 402         case ST_PERAG:
 403                 if (sm->sm_ino || sm->sm_gen ||
 404                     sm->sm_agno >= mp->m_sb.sb_agcount)
 405                         goto out;
 406                 break;
 407         case ST_INODE:
 408                 if (sm->sm_agno || (sm->sm_gen && !sm->sm_ino))
 409                         goto out;
 410                 break;
 411         default:
 412                 goto out;
 413         }
 414
 415         error = -EOPNOTSUPP;
 416         /*
 417          * We won't scrub any filesystem that doesn't have the ability
 418          * to record unwritten extents.  The option was made default in
 419          * 2003, removed from mkfs in 2007, and cannot be disabled in
 420          * v5, so if we find a filesystem without this flag it's either
 421          * really old or totally unsupported.  Avoid it either way.
 422          * We also don't support v1-v3 filesystems, which aren't
 423          * mountable.
 424          */
 425         if (!xfs_sb_version_hasextflgbit(&mp->m_sb))
 426                 goto out;
 427
 428         /*
 429          * We only want to repair read-write v5+ filesystems.  Defer the check
 430          * for ops->repair until after our scrub confirms that we need to
 431          * perform repairs so that we avoid failing due to not supporting
 432          * repairing an object that doesn't need repairs.
 433          */
 434         if (sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) {
 435                 error = -EOPNOTSUPP;
 436                 if (!xfs_sb_version_hascrc(&mp->m_sb))
 437                         goto out;
 438
 439                 error = -EROFS;
 440                 if (mp->m_flags & XFS_MOUNT_RDONLY)
 441                         goto out;
 442         }
 443
 444         error = 0;
 445 out:
 446         return error;
 447 }
 448
 449 #ifdef CONFIG_XFS_ONLINE_REPAIR
 450 static inline void xchk_postmortem(struct xfs_scrub *sc)
 451 {
 452         /*
 453          * Userspace asked us to repair something, we repaired it, rescanned
 454          * it, and the rescan says it's still broken.  Scream about this in
 455          * the system logs.
 456          */
 457         if ((sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) &&
 458             (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
 459                                  XFS_SCRUB_OFLAG_XCORRUPT)))
 460                 xrep_failure(sc->mp);
 461 }
 462 #else
 463 static inline void xchk_postmortem(struct xfs_scrub *sc)
 464 {
 465         /*
 466          * Userspace asked us to scrub something, it's broken, and we have no
 467          * way of fixing it.  Scream in the logs.
 468          */
 469         if (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
 470                                 XFS_SCRUB_OFLAG_XCORRUPT))
 471                 xfs_alert_ratelimited(sc->mp,
 472                                 "Corruption detected during scrub.");
 473 }
 474 #endif /* CONFIG_XFS_ONLINE_REPAIR */
 475
 476 /* Dispatch metadata scrubbing. */
 477 int
 478 xfs_scrub_metadata(
 479         struct xfs_inode                *ip,
 480         struct xfs_scrub_metadata       *sm)
 481 {
 482         struct xfs_scrub                sc;
 483         struct xfs_mount                *mp = ip->i_mount;
 484         bool                            try_harder = false;
 485         bool                            already_fixed = false;
 486         int                             error = 0;
 487
 488         BUILD_BUG_ON(sizeof(meta_scrub_ops) !=
 489                 (sizeof(struct xchk_meta_ops) * XFS_SCRUB_TYPE_NR));
 490
 491         trace_xchk_start(ip, sm, error);
 492
 493         /* Forbidden if we are shut down or mounted norecovery. */
 494         error = -ESHUTDOWN;
 495         if (XFS_FORCED_SHUTDOWN(mp))
 496                 goto out;
 497         error = -ENOTRECOVERABLE;
 498         if (mp->m_flags & XFS_MOUNT_NORECOVERY)
 499                 goto out;
 500
 501         error = xchk_validate_inputs(mp, sm);
 502         if (error)
 503                 goto out;
 504
 505         xchk_experimental_warning(mp);
 506
 507 retry_op:
 508         /* Set up for the operation. */
 509         memset(&sc, 0, sizeof(sc));
 510         sc.mp = ip->i_mount;
 511         sc.sm = sm;
 512         sc.ops = &meta_scrub_ops[sm->sm_type];
 513         sc.try_harder = try_harder;
 514         sc.sa.agno = NULLAGNUMBER;
 515         error = sc.ops->setup(&sc, ip);
 516         if (error)
 517                 goto out_teardown;
 518
 519         /* Scrub for errors. */
 520         error = sc.ops->scrub(&sc);
 521         if (!try_harder && error == -EDEADLOCK) {
 522                 /*
 523                  * Scrubbers return -EDEADLOCK to mean 'try harder'.
 524                  * Tear down everything we hold, then set up again with
 525                  * preparation for worst-case scenarios.
 526                  */
 527                 error = xchk_teardown(&sc, ip, 0);
 528                 if (error)
 529                         goto out;
 530                 try_harder = true;
 531                 goto retry_op;
 532         } else if (error)
 533                 goto out_teardown;
 534
 535         if ((sc.sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) && !already_fixed) {
 536                 bool needs_fix;
 537
 538                 /* Let debug users force us into the repair routines. */
 539                 if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_FORCE_SCRUB_REPAIR))
 540                         sc.sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
 541
 542                 needs_fix = (sc.sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
 543                                                 XFS_SCRUB_OFLAG_XCORRUPT |
 544                                                 XFS_SCRUB_OFLAG_PREEN));
 545                 /*
 546                  * If userspace asked for a repair but it wasn't necessary,
 547                  * report that back to userspace.
 548                  */
 549                 if (!needs_fix) {
 550                         sc.sm->sm_flags |= XFS_SCRUB_OFLAG_NO_REPAIR_NEEDED;
 551                         goto out_nofix;
 552                 }
 553
 554                 /*
 555                  * If it's broken, userspace wants us to fix it, and we haven't
 556                  * already tried to fix it, then attempt a repair.
 557                  */
 558                 error = xrep_attempt(ip, &sc, &already_fixed);
 559                 if (error == -EAGAIN) {
 560                         if (sc.try_harder)
 561                                 try_harder = true;
 562                         error = xchk_teardown(&sc, ip, 0);
 563                         if (error) {
 564                                 xrep_failure(mp);
 565                                 goto out;
 566                         }
 567                         goto retry_op;
 568                 }
 569         }
 570
 571 out_nofix:
 572         xchk_postmortem(&sc);
 573 out_teardown:
 574         error = xchk_teardown(&sc, ip, error);
 575 out:
 576         trace_xchk_done(ip, sm, error);
 577         if (error == -EFSCORRUPTED || error == -EFSBADCRC) {
 578                 sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
 579                 error = 0;
 580         }
 581         return error;
 582 }