fs/xfs/scrub/bmap.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_btree.h"
  13 #include "xfs_bit.h"
  14 #include "xfs_log_format.h"
  15 #include "xfs_trans.h"
  16 #include "xfs_inode.h"
  17 #include "xfs_alloc.h"
  18 #include "xfs_bmap.h"
  19 #include "xfs_bmap_btree.h"
  20 #include "xfs_rmap.h"
  21 #include "xfs_rmap_btree.h"
  22 #include "scrub/scrub.h"
  23 #include "scrub/common.h"
  24 #include "scrub/btree.h"
  25
  26 /* Set us up with an inode's bmap. */
  27 int
  28 xchk_setup_inode_bmap(
  29         struct xfs_scrub        *sc,
  30         struct xfs_inode        *ip)
  31 {
  32         int                     error;
  33
  34         error = xchk_get_inode(sc, ip);
  35         if (error)
  36                 goto out;
  37
  38         sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
  39         xfs_ilock(sc->ip, sc->ilock_flags);
  40
  41         /*
  42          * We don't want any ephemeral data fork updates sitting around
  43          * while we inspect block mappings, so wait for directio to finish
  44          * and flush dirty data if we have delalloc reservations.
  45          */
  46         if (S_ISREG(VFS_I(sc->ip)->i_mode) &&
  47             sc->sm->sm_type == XFS_SCRUB_TYPE_BMBTD) {
  48                 struct address_space    *mapping = VFS_I(sc->ip)->i_mapping;
  49
  50                 inode_dio_wait(VFS_I(sc->ip));
  51
  52                 /*
  53                  * Try to flush all incore state to disk before we examine the
  54                  * space mappings for the data fork.  Leave accumulated errors
  55                  * in the mapping for the writer threads to consume.
  56                  *
  57                  * On ENOSPC or EIO writeback errors, we continue into the
  58                  * extent mapping checks because write failures do not
  59                  * necessarily imply anything about the correctness of the file
  60                  * metadata.  The metadata and the file data could be on
  61                  * completely separate devices; a media failure might only
  62                  * affect a subset of the disk, etc.  We can handle delalloc
  63                  * extents in the scrubber, so leaving them in memory is fine.
  64                  */
  65                 error = filemap_fdatawrite(mapping);
  66                 if (!error)
  67                         error = filemap_fdatawait_keep_errors(mapping);
  68                 if (error && (error != -ENOSPC && error != -EIO))
  69                         goto out;
  70         }
  71
  72         /* Got the inode, lock it and we're ready to go. */
  73         error = xchk_trans_alloc(sc, 0);
  74         if (error)
  75                 goto out;
  76         sc->ilock_flags |= XFS_ILOCK_EXCL;
  77         xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
  78
  79 out:
  80         /* scrub teardown will unlock and release the inode */
  81         return error;
  82 }
  83
  84 /*
  85  * Inode fork block mapping (BMBT) scrubber.
  86  * More complex than the others because we have to scrub
  87  * all the extents regardless of whether or not the fork
  88  * is in btree format.
  89  */
  90
  91 struct xchk_bmap_info {
  92         struct xfs_scrub        *sc;
  93         xfs_fileoff_t           lastoff;
  94         bool                    is_rt;
  95         bool                    is_shared;
  96         bool                    was_loaded;
  97         int                     whichfork;
  98 };
  99
 100 /* Look for a corresponding rmap for this irec. */
 101 static inline bool
 102 xchk_bmap_get_rmap(
 103         struct xchk_bmap_info   *info,
 104         struct xfs_bmbt_irec    *irec,
 105         xfs_agblock_t           agbno,
 106         uint64_t                owner,
 107         struct xfs_rmap_irec    *rmap)
 108 {
 109         xfs_fileoff_t           offset;
 110         unsigned int            rflags = 0;
 111         int                     has_rmap;
 112         int                     error;
 113
 114         if (info->whichfork == XFS_ATTR_FORK)
 115                 rflags |= XFS_RMAP_ATTR_FORK;
 116         if (irec->br_state == XFS_EXT_UNWRITTEN)
 117                 rflags |= XFS_RMAP_UNWRITTEN;
 118
 119         /*
 120          * CoW staging extents are owned (on disk) by the refcountbt, so
 121          * their rmaps do not have offsets.
 122          */
 123         if (info->whichfork == XFS_COW_FORK)
 124                 offset = 0;
 125         else
 126                 offset = irec->br_startoff;
 127
 128         /*
 129          * If the caller thinks this could be a shared bmbt extent (IOWs,
 130          * any data fork extent of a reflink inode) then we have to use the
 131          * range rmap lookup to make sure we get the correct owner/offset.
 132          */
 133         if (info->is_shared) {
 134                 error = xfs_rmap_lookup_le_range(info->sc->sa.rmap_cur, agbno,
 135                                 owner, offset, rflags, rmap, &has_rmap);
 136                 if (!xchk_should_check_xref(info->sc, &error,
 137                                 &info->sc->sa.rmap_cur))
 138                         return false;
 139                 goto out;
 140         }
 141
 142         /*
 143          * Otherwise, use the (faster) regular lookup.
 144          */
 145         error = xfs_rmap_lookup_le(info->sc->sa.rmap_cur, agbno, 0, owner,
 146                         offset, rflags, &has_rmap);
 147         if (!xchk_should_check_xref(info->sc, &error,
 148                         &info->sc->sa.rmap_cur))
 149                 return false;
 150         if (!has_rmap)
 151                 goto out;
 152
 153         error = xfs_rmap_get_rec(info->sc->sa.rmap_cur, rmap, &has_rmap);
 154         if (!xchk_should_check_xref(info->sc, &error,
 155                         &info->sc->sa.rmap_cur))
 156                 return false;
 157
 158 out:
 159         if (!has_rmap)
 160                 xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
 161                         irec->br_startoff);
 162         return has_rmap;
 163 }
 164
 165 /* Make sure that we have rmapbt records for this extent. */
 166 STATIC void
 167 xchk_bmap_xref_rmap(
 168         struct xchk_bmap_info   *info,
 169         struct xfs_bmbt_irec    *irec,
 170         xfs_agblock_t           agbno)
 171 {
 172         struct xfs_rmap_irec    rmap;
 173         unsigned long long      rmap_end;
 174         uint64_t                owner;
 175
 176         if (!info->sc->sa.rmap_cur || xchk_skip_xref(info->sc->sm))
 177                 return;
 178
 179         if (info->whichfork == XFS_COW_FORK)
 180                 owner = XFS_RMAP_OWN_COW;
 181         else
 182                 owner = info->sc->ip->i_ino;
 183
 184         /* Find the rmap record for this irec. */
 185         if (!xchk_bmap_get_rmap(info, irec, agbno, owner, &rmap))
 186                 return;
 187
 188         /* Check the rmap. */
 189         rmap_end = (unsigned long long)rmap.rm_startblock + rmap.rm_blockcount;
 190         if (rmap.rm_startblock > agbno ||
 191             agbno + irec->br_blockcount > rmap_end)
 192                 xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
 193                                 irec->br_startoff);
 194
 195         /*
 196          * Check the logical offsets if applicable.  CoW staging extents
 197          * don't track logical offsets since the mappings only exist in
 198          * memory.
 199          */
 200         if (info->whichfork != XFS_COW_FORK) {
 201                 rmap_end = (unsigned long long)rmap.rm_offset +
 202                                 rmap.rm_blockcount;
 203                 if (rmap.rm_offset > irec->br_startoff ||
 204                     irec->br_startoff + irec->br_blockcount > rmap_end)
 205                         xchk_fblock_xref_set_corrupt(info->sc,
 206                                         info->whichfork, irec->br_startoff);
 207         }
 208
 209         if (rmap.rm_owner != owner)
 210                 xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
 211                                 irec->br_startoff);
 212
 213         /*
 214          * Check for discrepancies between the unwritten flag in the irec and
 215          * the rmap.  Note that the (in-memory) CoW fork distinguishes between
 216          * unwritten and written extents, but we don't track that in the rmap
 217          * records because the blocks are owned (on-disk) by the refcountbt,
 218          * which doesn't track unwritten state.
 219          */
 220         if (owner != XFS_RMAP_OWN_COW &&
 221             !!(irec->br_state == XFS_EXT_UNWRITTEN) !=
 222             !!(rmap.rm_flags & XFS_RMAP_UNWRITTEN))
 223                 xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
 224                                 irec->br_startoff);
 225
 226         if (!!(info->whichfork == XFS_ATTR_FORK) !=
 227             !!(rmap.rm_flags & XFS_RMAP_ATTR_FORK))
 228                 xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
 229                                 irec->br_startoff);
 230         if (rmap.rm_flags & XFS_RMAP_BMBT_BLOCK)
 231                 xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
 232                                 irec->br_startoff);
 233 }
 234
 235 /* Cross-reference a single rtdev extent record. */
 236 STATIC void
 237 xchk_bmap_rt_iextent_xref(
 238         struct xfs_inode        *ip,
 239         struct xchk_bmap_info   *info,
 240         struct xfs_bmbt_irec    *irec)
 241 {
 242         xchk_xref_is_used_rt_space(info->sc, irec->br_startblock,
 243                         irec->br_blockcount);
 244 }
 245
 246 /* Cross-reference a single datadev extent record. */
 247 STATIC void
 248 xchk_bmap_iextent_xref(
 249         struct xfs_inode        *ip,
 250         struct xchk_bmap_info   *info,
 251         struct xfs_bmbt_irec    *irec)
 252 {
 253         struct xfs_mount        *mp = info->sc->mp;
 254         xfs_agnumber_t          agno;
 255         xfs_agblock_t           agbno;
 256         xfs_extlen_t            len;
 257         int                     error;
 258
 259         agno = XFS_FSB_TO_AGNO(mp, irec->br_startblock);
 260         agbno = XFS_FSB_TO_AGBNO(mp, irec->br_startblock);
 261         len = irec->br_blockcount;
 262
 263         error = xchk_ag_init(info->sc, agno, &info->sc->sa);
 264         if (!xchk_fblock_process_error(info->sc, info->whichfork,
 265                         irec->br_startoff, &error))
 266                 return;
 267
 268         xchk_xref_is_used_space(info->sc, agbno, len);
 269         xchk_xref_is_not_inode_chunk(info->sc, agbno, len);
 270         xchk_bmap_xref_rmap(info, irec, agbno);
 271         switch (info->whichfork) {
 272         case XFS_DATA_FORK:
 273                 if (xfs_is_reflink_inode(info->sc->ip))
 274                         break;
 275                 /* fall through */
 276         case XFS_ATTR_FORK:
 277                 xchk_xref_is_not_shared(info->sc, agbno,
 278                                 irec->br_blockcount);
 279                 break;
 280         case XFS_COW_FORK:
 281                 xchk_xref_is_cow_staging(info->sc, agbno,
 282                                 irec->br_blockcount);
 283                 break;
 284         }
 285
 286         xchk_ag_free(info->sc, &info->sc->sa);
 287 }
 288
 289 /*
 290  * Directories and attr forks should never have blocks that can't be addressed
 291  * by a xfs_dablk_t.
 292  */
 293 STATIC void
 294 xchk_bmap_dirattr_extent(
 295         struct xfs_inode        *ip,
 296         struct xchk_bmap_info   *info,
 297         struct xfs_bmbt_irec    *irec)
 298 {
 299         struct xfs_mount        *mp = ip->i_mount;
 300         xfs_fileoff_t           off;
 301
 302         if (!S_ISDIR(VFS_I(ip)->i_mode) && info->whichfork != XFS_ATTR_FORK)
 303                 return;
 304
 305         if (!xfs_verify_dablk(mp, irec->br_startoff))
 306                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 307                                 irec->br_startoff);
 308
 309         off = irec->br_startoff + irec->br_blockcount - 1;
 310         if (!xfs_verify_dablk(mp, off))
 311                 xchk_fblock_set_corrupt(info->sc, info->whichfork, off);
 312 }
 313
 314 /* Scrub a single extent record. */
 315 STATIC int
 316 xchk_bmap_iextent(
 317         struct xfs_inode        *ip,
 318         struct xchk_bmap_info   *info,
 319         struct xfs_bmbt_irec    *irec)
 320 {
 321         struct xfs_mount        *mp = info->sc->mp;
 322         int                     error = 0;
 323
 324         /*
 325          * Check for out-of-order extents.  This record could have come
 326          * from the incore list, for which there is no ordering check.
 327          */
 328         if (irec->br_startoff < info->lastoff)
 329                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 330                                 irec->br_startoff);
 331
 332         xchk_bmap_dirattr_extent(ip, info, irec);
 333
 334         /* There should never be a "hole" extent in either extent list. */
 335         if (irec->br_startblock == HOLESTARTBLOCK)
 336                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 337                                 irec->br_startoff);
 338
 339         /*
 340          * Check for delalloc extents.  We never iterate the ones in the
 341          * in-core extent scan, and we should never see these in the bmbt.
 342          */
 343         if (isnullstartblock(irec->br_startblock))
 344                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 345                                 irec->br_startoff);
 346
 347         /* Make sure the extent points to a valid place. */
 348         if (irec->br_blockcount > MAXEXTLEN)
 349                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 350                                 irec->br_startoff);
 351         if (info->is_rt &&
 352             !xfs_verify_rtext(mp, irec->br_startblock, irec->br_blockcount))
 353                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 354                                 irec->br_startoff);
 355         if (!info->is_rt &&
 356             !xfs_verify_fsbext(mp, irec->br_startblock, irec->br_blockcount))
 357                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 358                                 irec->br_startoff);
 359
 360         /* We don't allow unwritten extents on attr forks. */
 361         if (irec->br_state == XFS_EXT_UNWRITTEN &&
 362             info->whichfork == XFS_ATTR_FORK)
 363                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 364                                 irec->br_startoff);
 365
 366         if (info->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 367                 return 0;
 368
 369         if (info->is_rt)
 370                 xchk_bmap_rt_iextent_xref(ip, info, irec);
 371         else
 372                 xchk_bmap_iextent_xref(ip, info, irec);
 373
 374         info->lastoff = irec->br_startoff + irec->br_blockcount;
 375         return error;
 376 }
 377
 378 /* Scrub a bmbt record. */
 379 STATIC int
 380 xchk_bmapbt_rec(
 381         struct xchk_btree       *bs,
 382         union xfs_btree_rec     *rec)
 383 {
 384         struct xfs_bmbt_irec    irec;
 385         struct xfs_bmbt_irec    iext_irec;
 386         struct xfs_iext_cursor  icur;
 387         struct xchk_bmap_info   *info = bs->private;
 388         struct xfs_inode        *ip = bs->cur->bc_ino.ip;
 389         struct xfs_buf          *bp = NULL;
 390         struct xfs_btree_block  *block;
 391         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, info->whichfork);
 392         uint64_t                owner;
 393         int                     i;
 394
 395         /*
 396          * Check the owners of the btree blocks up to the level below
 397          * the root since the verifiers don't do that.
 398          */
 399         if (xfs_sb_version_hascrc(&bs->cur->bc_mp->m_sb) &&
 400             bs->cur->bc_ptrs[0] == 1) {
 401                 for (i = 0; i < bs->cur->bc_nlevels - 1; i++) {
 402                         block = xfs_btree_get_block(bs->cur, i, &bp);
 403                         owner = be64_to_cpu(block->bb_u.l.bb_owner);
 404                         if (owner != ip->i_ino)
 405                                 xchk_fblock_set_corrupt(bs->sc,
 406                                                 info->whichfork, 0);
 407                 }
 408         }
 409
 410         /*
 411          * Check that the incore extent tree contains an extent that matches
 412          * this one exactly.  We validate those cached bmaps later, so we don't
 413          * need to check them here.  If the incore extent tree was just loaded
 414          * from disk by the scrubber, we assume that its contents match what's
 415          * on disk (we still hold the ILOCK) and skip the equivalence check.
 416          */
 417         if (!info->was_loaded)
 418                 return 0;
 419
 420         xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
 421         if (!xfs_iext_lookup_extent(ip, ifp, irec.br_startoff, &icur,
 422                                 &iext_irec) ||
 423             irec.br_startoff != iext_irec.br_startoff ||
 424             irec.br_startblock != iext_irec.br_startblock ||
 425             irec.br_blockcount != iext_irec.br_blockcount ||
 426             irec.br_state != iext_irec.br_state)
 427                 xchk_fblock_set_corrupt(bs->sc, info->whichfork,
 428                                 irec.br_startoff);
 429         return 0;
 430 }
 431
 432 /* Scan the btree records. */
 433 STATIC int
 434 xchk_bmap_btree(
 435         struct xfs_scrub        *sc,
 436         int                     whichfork,
 437         struct xchk_bmap_info   *info)
 438 {
 439         struct xfs_owner_info   oinfo;
 440         struct xfs_ifork        *ifp = XFS_IFORK_PTR(sc->ip, whichfork);
 441         struct xfs_mount        *mp = sc->mp;
 442         struct xfs_inode        *ip = sc->ip;
 443         struct xfs_btree_cur    *cur;
 444         int                     error;
 445
 446         /* Load the incore bmap cache if it's not loaded. */
 447         info->was_loaded = ifp->if_flags & XFS_IFEXTENTS;
 448         if (!info->was_loaded) {
 449                 error = xfs_iread_extents(sc->tp, ip, whichfork);
 450                 if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
 451                         goto out;
 452         }
 453
 454         /* Check the btree structure. */
 455         cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork);
 456         xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
 457         error = xchk_btree(sc, cur, xchk_bmapbt_rec, &oinfo, info);
 458         xfs_btree_del_cursor(cur, error);
 459 out:
 460         return error;
 461 }
 462
 463 struct xchk_bmap_check_rmap_info {
 464         struct xfs_scrub        *sc;
 465         int                     whichfork;
 466         struct xfs_iext_cursor  icur;
 467 };
 468
 469 /* Can we find bmaps that fit this rmap? */
 470 STATIC int
 471 xchk_bmap_check_rmap(
 472         struct xfs_btree_cur            *cur,
 473         struct xfs_rmap_irec            *rec,
 474         void                            *priv)
 475 {
 476         struct xfs_bmbt_irec            irec;
 477         struct xchk_bmap_check_rmap_info        *sbcri = priv;
 478         struct xfs_ifork                *ifp;
 479         struct xfs_scrub                *sc = sbcri->sc;
 480         bool                            have_map;
 481
 482         /* Is this even the right fork? */
 483         if (rec->rm_owner != sc->ip->i_ino)
 484                 return 0;
 485         if ((sbcri->whichfork == XFS_ATTR_FORK) ^
 486             !!(rec->rm_flags & XFS_RMAP_ATTR_FORK))
 487                 return 0;
 488         if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
 489                 return 0;
 490
 491         /* Now look up the bmbt record. */
 492         ifp = XFS_IFORK_PTR(sc->ip, sbcri->whichfork);
 493         if (!ifp) {
 494                 xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 495                                 rec->rm_offset);
 496                 goto out;
 497         }
 498         have_map = xfs_iext_lookup_extent(sc->ip, ifp, rec->rm_offset,
 499                         &sbcri->icur, &irec);
 500         if (!have_map)
 501                 xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 502                                 rec->rm_offset);
 503         /*
 504          * bmap extent record lengths are constrained to 2^21 blocks in length
 505          * because of space constraints in the on-disk metadata structure.
 506          * However, rmap extent record lengths are constrained only by AG
 507          * length, so we have to loop through the bmbt to make sure that the
 508          * entire rmap is covered by bmbt records.
 509          */
 510         while (have_map) {
 511                 if (irec.br_startoff != rec->rm_offset)
 512                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 513                                         rec->rm_offset);
 514                 if (irec.br_startblock != XFS_AGB_TO_FSB(sc->mp,
 515                                 cur->bc_ag.agno, rec->rm_startblock))
 516                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 517                                         rec->rm_offset);
 518                 if (irec.br_blockcount > rec->rm_blockcount)
 519                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 520                                         rec->rm_offset);
 521                 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 522                         break;
 523                 rec->rm_startblock += irec.br_blockcount;
 524                 rec->rm_offset += irec.br_blockcount;
 525                 rec->rm_blockcount -= irec.br_blockcount;
 526                 if (rec->rm_blockcount == 0)
 527                         break;
 528                 have_map = xfs_iext_next_extent(ifp, &sbcri->icur, &irec);
 529                 if (!have_map)
 530                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 531                                         rec->rm_offset);
 532         }
 533
 534 out:
 535         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 536                 return -ECANCELED;
 537         return 0;
 538 }
 539
 540 /* Make sure each rmap has a corresponding bmbt entry. */
 541 STATIC int
 542 xchk_bmap_check_ag_rmaps(
 543         struct xfs_scrub                *sc,
 544         int                             whichfork,
 545         xfs_agnumber_t                  agno)
 546 {
 547         struct xchk_bmap_check_rmap_info        sbcri;
 548         struct xfs_btree_cur            *cur;
 549         struct xfs_buf                  *agf;
 550         int                             error;
 551
 552         error = xfs_alloc_read_agf(sc->mp, sc->tp, agno, 0, &agf);
 553         if (error)
 554                 return error;
 555
 556         cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf, agno);
 557         if (!cur) {
 558                 error = -ENOMEM;
 559                 goto out_agf;
 560         }
 561
 562         sbcri.sc = sc;
 563         sbcri.whichfork = whichfork;
 564         error = xfs_rmap_query_all(cur, xchk_bmap_check_rmap, &sbcri);
 565         if (error == -ECANCELED)
 566                 error = 0;
 567
 568         xfs_btree_del_cursor(cur, error);
 569 out_agf:
 570         xfs_trans_brelse(sc->tp, agf);
 571         return error;
 572 }
 573
 574 /* Make sure each rmap has a corresponding bmbt entry. */
 575 STATIC int
 576 xchk_bmap_check_rmaps(
 577         struct xfs_scrub        *sc,
 578         int                     whichfork)
 579 {
 580         struct xfs_ifork        *ifp = XFS_IFORK_PTR(sc->ip, whichfork);
 581         xfs_agnumber_t          agno;
 582         bool                    zero_size;
 583         int                     error;
 584
 585         if (!xfs_sb_version_hasrmapbt(&sc->mp->m_sb) ||
 586             whichfork == XFS_COW_FORK ||
 587             (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
 588                 return 0;
 589
 590         /* Don't support realtime rmap checks yet. */
 591         if (XFS_IS_REALTIME_INODE(sc->ip) && whichfork == XFS_DATA_FORK)
 592                 return 0;
 593
 594         ASSERT(XFS_IFORK_PTR(sc->ip, whichfork) != NULL);
 595
 596         /*
 597          * Only do this for complex maps that are in btree format, or for
 598          * situations where we would seem to have a size but zero extents.
 599          * The inode repair code can zap broken iforks, which means we have
 600          * to flag this bmap as corrupt if there are rmaps that need to be
 601          * reattached.
 602          */
 603
 604         if (whichfork == XFS_DATA_FORK)
 605                 zero_size = i_size_read(VFS_I(sc->ip)) == 0;
 606         else
 607                 zero_size = false;
 608
 609         if (ifp->if_format != XFS_DINODE_FMT_BTREE &&
 610             (zero_size || ifp->if_nextents > 0))
 611                 return 0;
 612
 613         for (agno = 0; agno < sc->mp->m_sb.sb_agcount; agno++) {
 614                 error = xchk_bmap_check_ag_rmaps(sc, whichfork, agno);
 615                 if (error)
 616                         return error;
 617                 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 618                         break;
 619         }
 620
 621         return 0;
 622 }
 623
 624 /*
 625  * Scrub an inode fork's block mappings.
 626  *
 627  * First we scan every record in every btree block, if applicable.
 628  * Then we unconditionally scan the incore extent cache.
 629  */
 630 STATIC int
 631 xchk_bmap(
 632         struct xfs_scrub        *sc,
 633         int                     whichfork)
 634 {
 635         struct xfs_bmbt_irec    irec;
 636         struct xchk_bmap_info   info = { NULL };
 637         struct xfs_mount        *mp = sc->mp;
 638         struct xfs_inode        *ip = sc->ip;
 639         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
 640         xfs_fileoff_t           endoff;
 641         struct xfs_iext_cursor  icur;
 642         int                     error = 0;
 643
 644         /* Non-existent forks can be ignored. */
 645         if (!ifp)
 646                 goto out;
 647
 648         info.is_rt = whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip);
 649         info.whichfork = whichfork;
 650         info.is_shared = whichfork == XFS_DATA_FORK && xfs_is_reflink_inode(ip);
 651         info.sc = sc;
 652
 653         switch (whichfork) {
 654         case XFS_COW_FORK:
 655                 /* No CoW forks on non-reflink inodes/filesystems. */
 656                 if (!xfs_is_reflink_inode(ip)) {
 657                         xchk_ino_set_corrupt(sc, sc->ip->i_ino);
 658                         goto out;
 659                 }
 660                 break;
 661         case XFS_ATTR_FORK:
 662                 if (!xfs_sb_version_hasattr(&mp->m_sb) &&
 663                     !xfs_sb_version_hasattr2(&mp->m_sb))
 664                         xchk_ino_set_corrupt(sc, sc->ip->i_ino);
 665                 break;
 666         default:
 667                 ASSERT(whichfork == XFS_DATA_FORK);
 668                 break;
 669         }
 670
 671         /* Check the fork values */
 672         switch (ifp->if_format) {
 673         case XFS_DINODE_FMT_UUID:
 674         case XFS_DINODE_FMT_DEV:
 675         case XFS_DINODE_FMT_LOCAL:
 676                 /* No mappings to check. */
 677                 goto out;
 678         case XFS_DINODE_FMT_EXTENTS:
 679                 if (!(ifp->if_flags & XFS_IFEXTENTS)) {
 680                         xchk_fblock_set_corrupt(sc, whichfork, 0);
 681                         goto out;
 682                 }
 683                 break;
 684         case XFS_DINODE_FMT_BTREE:
 685                 if (whichfork == XFS_COW_FORK) {
 686                         xchk_fblock_set_corrupt(sc, whichfork, 0);
 687                         goto out;
 688                 }
 689
 690                 error = xchk_bmap_btree(sc, whichfork, &info);
 691                 if (error)
 692                         goto out;
 693                 break;
 694         default:
 695                 xchk_fblock_set_corrupt(sc, whichfork, 0);
 696                 goto out;
 697         }
 698
 699         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 700                 goto out;
 701
 702         /* Find the offset of the last extent in the mapping. */
 703         error = xfs_bmap_last_offset(ip, &endoff, whichfork);
 704         if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
 705                 goto out;
 706
 707         /* Scrub extent records. */
 708         info.lastoff = 0;
 709         ifp = XFS_IFORK_PTR(ip, whichfork);
 710         for_each_xfs_iext(ifp, &icur, &irec) {
 711                 if (xchk_should_terminate(sc, &error) ||
 712                     (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
 713                         goto out;
 714                 if (isnullstartblock(irec.br_startblock))
 715                         continue;
 716                 if (irec.br_startoff >= endoff) {
 717                         xchk_fblock_set_corrupt(sc, whichfork,
 718                                         irec.br_startoff);
 719                         goto out;
 720                 }
 721                 error = xchk_bmap_iextent(ip, &info, &irec);
 722                 if (error)
 723                         goto out;
 724         }
 725
 726         error = xchk_bmap_check_rmaps(sc, whichfork);
 727         if (!xchk_fblock_xref_process_error(sc, whichfork, 0, &error))
 728                 goto out;
 729 out:
 730         return error;
 731 }
 732
 733 /* Scrub an inode's data fork. */
 734 int
 735 xchk_bmap_data(
 736         struct xfs_scrub        *sc)
 737 {
 738         return xchk_bmap(sc, XFS_DATA_FORK);
 739 }
 740
 741 /* Scrub an inode's attr fork. */
 742 int
 743 xchk_bmap_attr(
 744         struct xfs_scrub        *sc)
 745 {
 746         return xchk_bmap(sc, XFS_ATTR_FORK);
 747 }
 748
 749 /* Scrub an inode's CoW fork. */
 750 int
 751 xchk_bmap_cow(
 752         struct xfs_scrub        *sc)
 753 {
 754         if (!xfs_is_reflink_inode(sc->ip))
 755                 return -ENOENT;
 756
 757         return xchk_bmap(sc, XFS_COW_FORK);
 758 }