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 #include "xfs_ag.h"
  26
  27 /* Set us up with an inode's bmap. */
  28 int
  29 xchk_setup_inode_bmap(
  30         struct xfs_scrub        *sc)
  31 {
  32         int                     error;
  33
  34         error = xchk_get_inode(sc);
  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         if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount))
 333                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 334                                 irec->br_startoff);
 335
 336         xchk_bmap_dirattr_extent(ip, info, irec);
 337
 338         /* There should never be a "hole" extent in either extent list. */
 339         if (irec->br_startblock == HOLESTARTBLOCK)
 340                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 341                                 irec->br_startoff);
 342
 343         /*
 344          * Check for delalloc extents.  We never iterate the ones in the
 345          * in-core extent scan, and we should never see these in the bmbt.
 346          */
 347         if (isnullstartblock(irec->br_startblock))
 348                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 349                                 irec->br_startoff);
 350
 351         /* Make sure the extent points to a valid place. */
 352         if (irec->br_blockcount > MAXEXTLEN)
 353                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 354                                 irec->br_startoff);
 355         if (info->is_rt &&
 356             !xfs_verify_rtext(mp, irec->br_startblock, irec->br_blockcount))
 357                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 358                                 irec->br_startoff);
 359         if (!info->is_rt &&
 360             !xfs_verify_fsbext(mp, irec->br_startblock, irec->br_blockcount))
 361                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 362                                 irec->br_startoff);
 363
 364         /* We don't allow unwritten extents on attr forks. */
 365         if (irec->br_state == XFS_EXT_UNWRITTEN &&
 366             info->whichfork == XFS_ATTR_FORK)
 367                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 368                                 irec->br_startoff);
 369
 370         if (info->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 371                 return 0;
 372
 373         if (info->is_rt)
 374                 xchk_bmap_rt_iextent_xref(ip, info, irec);
 375         else
 376                 xchk_bmap_iextent_xref(ip, info, irec);
 377
 378         info->lastoff = irec->br_startoff + irec->br_blockcount;
 379         return error;
 380 }
 381
 382 /* Scrub a bmbt record. */
 383 STATIC int
 384 xchk_bmapbt_rec(
 385         struct xchk_btree       *bs,
 386         union xfs_btree_rec     *rec)
 387 {
 388         struct xfs_bmbt_irec    irec;
 389         struct xfs_bmbt_irec    iext_irec;
 390         struct xfs_iext_cursor  icur;
 391         struct xchk_bmap_info   *info = bs->private;
 392         struct xfs_inode        *ip = bs->cur->bc_ino.ip;
 393         struct xfs_buf          *bp = NULL;
 394         struct xfs_btree_block  *block;
 395         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, info->whichfork);
 396         uint64_t                owner;
 397         int                     i;
 398
 399         /*
 400          * Check the owners of the btree blocks up to the level below
 401          * the root since the verifiers don't do that.
 402          */
 403         if (xfs_sb_version_hascrc(&bs->cur->bc_mp->m_sb) &&
 404             bs->cur->bc_ptrs[0] == 1) {
 405                 for (i = 0; i < bs->cur->bc_nlevels - 1; i++) {
 406                         block = xfs_btree_get_block(bs->cur, i, &bp);
 407                         owner = be64_to_cpu(block->bb_u.l.bb_owner);
 408                         if (owner != ip->i_ino)
 409                                 xchk_fblock_set_corrupt(bs->sc,
 410                                                 info->whichfork, 0);
 411                 }
 412         }
 413
 414         /*
 415          * Check that the incore extent tree contains an extent that matches
 416          * this one exactly.  We validate those cached bmaps later, so we don't
 417          * need to check them here.  If the incore extent tree was just loaded
 418          * from disk by the scrubber, we assume that its contents match what's
 419          * on disk (we still hold the ILOCK) and skip the equivalence check.
 420          */
 421         if (!info->was_loaded)
 422                 return 0;
 423
 424         xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
 425         if (!xfs_iext_lookup_extent(ip, ifp, irec.br_startoff, &icur,
 426                                 &iext_irec) ||
 427             irec.br_startoff != iext_irec.br_startoff ||
 428             irec.br_startblock != iext_irec.br_startblock ||
 429             irec.br_blockcount != iext_irec.br_blockcount ||
 430             irec.br_state != iext_irec.br_state)
 431                 xchk_fblock_set_corrupt(bs->sc, info->whichfork,
 432                                 irec.br_startoff);
 433         return 0;
 434 }
 435
 436 /* Scan the btree records. */
 437 STATIC int
 438 xchk_bmap_btree(
 439         struct xfs_scrub        *sc,
 440         int                     whichfork,
 441         struct xchk_bmap_info   *info)
 442 {
 443         struct xfs_owner_info   oinfo;
 444         struct xfs_ifork        *ifp = XFS_IFORK_PTR(sc->ip, whichfork);
 445         struct xfs_mount        *mp = sc->mp;
 446         struct xfs_inode        *ip = sc->ip;
 447         struct xfs_btree_cur    *cur;
 448         int                     error;
 449
 450         /* Load the incore bmap cache if it's not loaded. */
 451         info->was_loaded = !xfs_need_iread_extents(ifp);
 452
 453         error = xfs_iread_extents(sc->tp, ip, whichfork);
 454         if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
 455                 goto out;
 456
 457         /* Check the btree structure. */
 458         cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork);
 459         xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
 460         error = xchk_btree(sc, cur, xchk_bmapbt_rec, &oinfo, info);
 461         xfs_btree_del_cursor(cur, error);
 462 out:
 463         return error;
 464 }
 465
 466 struct xchk_bmap_check_rmap_info {
 467         struct xfs_scrub        *sc;
 468         int                     whichfork;
 469         struct xfs_iext_cursor  icur;
 470 };
 471
 472 /* Can we find bmaps that fit this rmap? */
 473 STATIC int
 474 xchk_bmap_check_rmap(
 475         struct xfs_btree_cur            *cur,
 476         struct xfs_rmap_irec            *rec,
 477         void                            *priv)
 478 {
 479         struct xfs_bmbt_irec            irec;
 480         struct xchk_bmap_check_rmap_info        *sbcri = priv;
 481         struct xfs_ifork                *ifp;
 482         struct xfs_scrub                *sc = sbcri->sc;
 483         bool                            have_map;
 484
 485         /* Is this even the right fork? */
 486         if (rec->rm_owner != sc->ip->i_ino)
 487                 return 0;
 488         if ((sbcri->whichfork == XFS_ATTR_FORK) ^
 489             !!(rec->rm_flags & XFS_RMAP_ATTR_FORK))
 490                 return 0;
 491         if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
 492                 return 0;
 493
 494         /* Now look up the bmbt record. */
 495         ifp = XFS_IFORK_PTR(sc->ip, sbcri->whichfork);
 496         if (!ifp) {
 497                 xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 498                                 rec->rm_offset);
 499                 goto out;
 500         }
 501         have_map = xfs_iext_lookup_extent(sc->ip, ifp, rec->rm_offset,
 502                         &sbcri->icur, &irec);
 503         if (!have_map)
 504                 xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 505                                 rec->rm_offset);
 506         /*
 507          * bmap extent record lengths are constrained to 2^21 blocks in length
 508          * because of space constraints in the on-disk metadata structure.
 509          * However, rmap extent record lengths are constrained only by AG
 510          * length, so we have to loop through the bmbt to make sure that the
 511          * entire rmap is covered by bmbt records.
 512          */
 513         while (have_map) {
 514                 if (irec.br_startoff != rec->rm_offset)
 515                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 516                                         rec->rm_offset);
 517                 if (irec.br_startblock != XFS_AGB_TO_FSB(sc->mp,
 518                                 cur->bc_ag.agno, rec->rm_startblock))
 519                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 520                                         rec->rm_offset);
 521                 if (irec.br_blockcount > rec->rm_blockcount)
 522                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 523                                         rec->rm_offset);
 524                 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 525                         break;
 526                 rec->rm_startblock += irec.br_blockcount;
 527                 rec->rm_offset += irec.br_blockcount;
 528                 rec->rm_blockcount -= irec.br_blockcount;
 529                 if (rec->rm_blockcount == 0)
 530                         break;
 531                 have_map = xfs_iext_next_extent(ifp, &sbcri->icur, &irec);
 532                 if (!have_map)
 533                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 534                                         rec->rm_offset);
 535         }
 536
 537 out:
 538         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 539                 return -ECANCELED;
 540         return 0;
 541 }
 542
 543 /* Make sure each rmap has a corresponding bmbt entry. */
 544 STATIC int
 545 xchk_bmap_check_ag_rmaps(
 546         struct xfs_scrub                *sc,
 547         int                             whichfork,
 548         xfs_agnumber_t                  agno)
 549 {
 550         struct xchk_bmap_check_rmap_info        sbcri;
 551         struct xfs_btree_cur            *cur;
 552         struct xfs_buf                  *agf;
 553         int                             error;
 554
 555         error = xfs_alloc_read_agf(sc->mp, sc->tp, agno, 0, &agf);
 556         if (error)
 557                 return error;
 558
 559         cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf, sc->sa.pag);
 560
 561         sbcri.sc = sc;
 562         sbcri.whichfork = whichfork;
 563         error = xfs_rmap_query_all(cur, xchk_bmap_check_rmap, &sbcri);
 564         if (error == -ECANCELED)
 565                 error = 0;
 566
 567         xfs_btree_del_cursor(cur, error);
 568         xfs_trans_brelse(sc->tp, agf);
 569         return error;
 570 }
 571
 572 /* Make sure each rmap has a corresponding bmbt entry. */
 573 STATIC int
 574 xchk_bmap_check_rmaps(
 575         struct xfs_scrub        *sc,
 576         int                     whichfork)
 577 {
 578         struct xfs_ifork        *ifp = XFS_IFORK_PTR(sc->ip, whichfork);
 579         struct xfs_perag        *pag;
 580         xfs_agnumber_t          agno;
 581         bool                    zero_size;
 582         int                     error;
 583
 584         if (!xfs_sb_version_hasrmapbt(&sc->mp->m_sb) ||
 585             whichfork == XFS_COW_FORK ||
 586             (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
 587                 return 0;
 588
 589         /* Don't support realtime rmap checks yet. */
 590         if (XFS_IS_REALTIME_INODE(sc->ip) && whichfork == XFS_DATA_FORK)
 591                 return 0;
 592
 593         ASSERT(XFS_IFORK_PTR(sc->ip, whichfork) != NULL);
 594
 595         /*
 596          * Only do this for complex maps that are in btree format, or for
 597          * situations where we would seem to have a size but zero extents.
 598          * The inode repair code can zap broken iforks, which means we have
 599          * to flag this bmap as corrupt if there are rmaps that need to be
 600          * reattached.
 601          */
 602
 603         if (whichfork == XFS_DATA_FORK)
 604                 zero_size = i_size_read(VFS_I(sc->ip)) == 0;
 605         else
 606                 zero_size = false;
 607
 608         if (ifp->if_format != XFS_DINODE_FMT_BTREE &&
 609             (zero_size || ifp->if_nextents > 0))
 610                 return 0;
 611
 612         for_each_perag(sc->mp, agno, pag) {
 613                 error = xchk_bmap_check_ag_rmaps(sc, whichfork, pag->pag_agno);
 614                 if (error)
 615                         break;
 616                 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 617                         break;
 618         }
 619         if (pag)
 620                 xfs_perag_put(pag);
 621         return error;
 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                 break;
 680         case XFS_DINODE_FMT_BTREE:
 681                 if (whichfork == XFS_COW_FORK) {
 682                         xchk_fblock_set_corrupt(sc, whichfork, 0);
 683                         goto out;
 684                 }
 685
 686                 error = xchk_bmap_btree(sc, whichfork, &info);
 687                 if (error)
 688                         goto out;
 689                 break;
 690         default:
 691                 xchk_fblock_set_corrupt(sc, whichfork, 0);
 692                 goto out;
 693         }
 694
 695         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 696                 goto out;
 697
 698         /* Find the offset of the last extent in the mapping. */
 699         error = xfs_bmap_last_offset(ip, &endoff, whichfork);
 700         if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
 701                 goto out;
 702
 703         /* Scrub extent records. */
 704         info.lastoff = 0;
 705         ifp = XFS_IFORK_PTR(ip, whichfork);
 706         for_each_xfs_iext(ifp, &icur, &irec) {
 707                 if (xchk_should_terminate(sc, &error) ||
 708                     (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
 709                         goto out;
 710                 if (isnullstartblock(irec.br_startblock))
 711                         continue;
 712                 if (irec.br_startoff >= endoff) {
 713                         xchk_fblock_set_corrupt(sc, whichfork,
 714                                         irec.br_startoff);
 715                         goto out;
 716                 }
 717                 error = xchk_bmap_iextent(ip, &info, &irec);
 718                 if (error)
 719                         goto out;
 720         }
 721
 722         error = xchk_bmap_check_rmaps(sc, whichfork);
 723         if (!xchk_fblock_xref_process_error(sc, whichfork, 0, &error))
 724                 goto out;
 725 out:
 726         return error;
 727 }
 728
 729 /* Scrub an inode's data fork. */
 730 int
 731 xchk_bmap_data(
 732         struct xfs_scrub        *sc)
 733 {
 734         return xchk_bmap(sc, XFS_DATA_FORK);
 735 }
 736
 737 /* Scrub an inode's attr fork. */
 738 int
 739 xchk_bmap_attr(
 740         struct xfs_scrub        *sc)
 741 {
 742         return xchk_bmap(sc, XFS_ATTR_FORK);
 743 }
 744
 745 /* Scrub an inode's CoW fork. */
 746 int
 747 xchk_bmap_cow(
 748         struct xfs_scrub        *sc)
 749 {
 750         if (!xfs_is_reflink_inode(sc->ip))
 751                 return -ENOENT;
 752
 753         return xchk_bmap(sc, XFS_COW_FORK);
 754 }