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_existing(info->sc, agno, &info->sc->sa);
 264         if (!xchk_fblock_process_error(info->sc, info->whichfork,
 265                         irec->br_startoff, &error))
 266                 goto out_free;
 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                 fallthrough;
 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 out_free:
 287         xchk_ag_free(info->sc, &info->sc->sa);
 288 }
 289
 290 /*
 291  * Directories and attr forks should never have blocks that can't be addressed
 292  * by a xfs_dablk_t.
 293  */
 294 STATIC void
 295 xchk_bmap_dirattr_extent(
 296         struct xfs_inode        *ip,
 297         struct xchk_bmap_info   *info,
 298         struct xfs_bmbt_irec    *irec)
 299 {
 300         struct xfs_mount        *mp = ip->i_mount;
 301         xfs_fileoff_t           off;
 302
 303         if (!S_ISDIR(VFS_I(ip)->i_mode) && info->whichfork != XFS_ATTR_FORK)
 304                 return;
 305
 306         if (!xfs_verify_dablk(mp, irec->br_startoff))
 307                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 308                                 irec->br_startoff);
 309
 310         off = irec->br_startoff + irec->br_blockcount - 1;
 311         if (!xfs_verify_dablk(mp, off))
 312                 xchk_fblock_set_corrupt(info->sc, info->whichfork, off);
 313 }
 314
 315 /* Scrub a single extent record. */
 316 STATIC int
 317 xchk_bmap_iextent(
 318         struct xfs_inode        *ip,
 319         struct xchk_bmap_info   *info,
 320         struct xfs_bmbt_irec    *irec)
 321 {
 322         struct xfs_mount        *mp = info->sc->mp;
 323         int                     error = 0;
 324
 325         /*
 326          * Check for out-of-order extents.  This record could have come
 327          * from the incore list, for which there is no ordering check.
 328          */
 329         if (irec->br_startoff < info->lastoff)
 330                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 331                                 irec->br_startoff);
 332
 333         if (!xfs_verify_fileext(mp, irec->br_startoff, irec->br_blockcount))
 334                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 335                                 irec->br_startoff);
 336
 337         xchk_bmap_dirattr_extent(ip, info, irec);
 338
 339         /* There should never be a "hole" extent in either extent list. */
 340         if (irec->br_startblock == HOLESTARTBLOCK)
 341                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 342                                 irec->br_startoff);
 343
 344         /*
 345          * Check for delalloc extents.  We never iterate the ones in the
 346          * in-core extent scan, and we should never see these in the bmbt.
 347          */
 348         if (isnullstartblock(irec->br_startblock))
 349                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 350                                 irec->br_startoff);
 351
 352         /* Make sure the extent points to a valid place. */
 353         if (irec->br_blockcount > MAXEXTLEN)
 354                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 355                                 irec->br_startoff);
 356         if (info->is_rt &&
 357             !xfs_verify_rtext(mp, irec->br_startblock, irec->br_blockcount))
 358                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 359                                 irec->br_startoff);
 360         if (!info->is_rt &&
 361             !xfs_verify_fsbext(mp, irec->br_startblock, irec->br_blockcount))
 362                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 363                                 irec->br_startoff);
 364
 365         /* We don't allow unwritten extents on attr forks. */
 366         if (irec->br_state == XFS_EXT_UNWRITTEN &&
 367             info->whichfork == XFS_ATTR_FORK)
 368                 xchk_fblock_set_corrupt(info->sc, info->whichfork,
 369                                 irec->br_startoff);
 370
 371         if (info->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 372                 return 0;
 373
 374         if (info->is_rt)
 375                 xchk_bmap_rt_iextent_xref(ip, info, irec);
 376         else
 377                 xchk_bmap_iextent_xref(ip, info, irec);
 378
 379         info->lastoff = irec->br_startoff + irec->br_blockcount;
 380         return error;
 381 }
 382
 383 /* Scrub a bmbt record. */
 384 STATIC int
 385 xchk_bmapbt_rec(
 386         struct xchk_btree       *bs,
 387         const union xfs_btree_rec *rec)
 388 {
 389         struct xfs_bmbt_irec    irec;
 390         struct xfs_bmbt_irec    iext_irec;
 391         struct xfs_iext_cursor  icur;
 392         struct xchk_bmap_info   *info = bs->private;
 393         struct xfs_inode        *ip = bs->cur->bc_ino.ip;
 394         struct xfs_buf          *bp = NULL;
 395         struct xfs_btree_block  *block;
 396         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, info->whichfork);
 397         uint64_t                owner;
 398         int                     i;
 399
 400         /*
 401          * Check the owners of the btree blocks up to the level below
 402          * the root since the verifiers don't do that.
 403          */
 404         if (xfs_has_crc(bs->cur->bc_mp) &&
 405             bs->cur->bc_ptrs[0] == 1) {
 406                 for (i = 0; i < bs->cur->bc_nlevels - 1; i++) {
 407                         block = xfs_btree_get_block(bs->cur, i, &bp);
 408                         owner = be64_to_cpu(block->bb_u.l.bb_owner);
 409                         if (owner != ip->i_ino)
 410                                 xchk_fblock_set_corrupt(bs->sc,
 411                                                 info->whichfork, 0);
 412                 }
 413         }
 414
 415         /*
 416          * Check that the incore extent tree contains an extent that matches
 417          * this one exactly.  We validate those cached bmaps later, so we don't
 418          * need to check them here.  If the incore extent tree was just loaded
 419          * from disk by the scrubber, we assume that its contents match what's
 420          * on disk (we still hold the ILOCK) and skip the equivalence check.
 421          */
 422         if (!info->was_loaded)
 423                 return 0;
 424
 425         xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
 426         if (!xfs_iext_lookup_extent(ip, ifp, irec.br_startoff, &icur,
 427                                 &iext_irec) ||
 428             irec.br_startoff != iext_irec.br_startoff ||
 429             irec.br_startblock != iext_irec.br_startblock ||
 430             irec.br_blockcount != iext_irec.br_blockcount ||
 431             irec.br_state != iext_irec.br_state)
 432                 xchk_fblock_set_corrupt(bs->sc, info->whichfork,
 433                                 irec.br_startoff);
 434         return 0;
 435 }
 436
 437 /* Scan the btree records. */
 438 STATIC int
 439 xchk_bmap_btree(
 440         struct xfs_scrub        *sc,
 441         int                     whichfork,
 442         struct xchk_bmap_info   *info)
 443 {
 444         struct xfs_owner_info   oinfo;
 445         struct xfs_ifork        *ifp = XFS_IFORK_PTR(sc->ip, whichfork);
 446         struct xfs_mount        *mp = sc->mp;
 447         struct xfs_inode        *ip = sc->ip;
 448         struct xfs_btree_cur    *cur;
 449         int                     error;
 450
 451         /* Load the incore bmap cache if it's not loaded. */
 452         info->was_loaded = !xfs_need_iread_extents(ifp);
 453
 454         error = xfs_iread_extents(sc->tp, ip, whichfork);
 455         if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
 456                 goto out;
 457
 458         /* Check the btree structure. */
 459         cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork);
 460         xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
 461         error = xchk_btree(sc, cur, xchk_bmapbt_rec, &oinfo, info);
 462         xfs_btree_del_cursor(cur, error);
 463 out:
 464         return error;
 465 }
 466
 467 struct xchk_bmap_check_rmap_info {
 468         struct xfs_scrub        *sc;
 469         int                     whichfork;
 470         struct xfs_iext_cursor  icur;
 471 };
 472
 473 /* Can we find bmaps that fit this rmap? */
 474 STATIC int
 475 xchk_bmap_check_rmap(
 476         struct xfs_btree_cur            *cur,
 477         const struct xfs_rmap_irec      *rec,
 478         void                            *priv)
 479 {
 480         struct xfs_bmbt_irec            irec;
 481         struct xfs_rmap_irec            check_rec;
 482         struct xchk_bmap_check_rmap_info        *sbcri = priv;
 483         struct xfs_ifork                *ifp;
 484         struct xfs_scrub                *sc = sbcri->sc;
 485         bool                            have_map;
 486
 487         /* Is this even the right fork? */
 488         if (rec->rm_owner != sc->ip->i_ino)
 489                 return 0;
 490         if ((sbcri->whichfork == XFS_ATTR_FORK) ^
 491             !!(rec->rm_flags & XFS_RMAP_ATTR_FORK))
 492                 return 0;
 493         if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
 494                 return 0;
 495
 496         /* Now look up the bmbt record. */
 497         ifp = XFS_IFORK_PTR(sc->ip, sbcri->whichfork);
 498         if (!ifp) {
 499                 xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 500                                 rec->rm_offset);
 501                 goto out;
 502         }
 503         have_map = xfs_iext_lookup_extent(sc->ip, ifp, rec->rm_offset,
 504                         &sbcri->icur, &irec);
 505         if (!have_map)
 506                 xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 507                                 rec->rm_offset);
 508         /*
 509          * bmap extent record lengths are constrained to 2^21 blocks in length
 510          * because of space constraints in the on-disk metadata structure.
 511          * However, rmap extent record lengths are constrained only by AG
 512          * length, so we have to loop through the bmbt to make sure that the
 513          * entire rmap is covered by bmbt records.
 514          */
 515         check_rec = *rec;
 516         while (have_map) {
 517                 if (irec.br_startoff != check_rec.rm_offset)
 518                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 519                                         check_rec.rm_offset);
 520                 if (irec.br_startblock != XFS_AGB_TO_FSB(sc->mp,
 521                                 cur->bc_ag.pag->pag_agno,
 522                                 check_rec.rm_startblock))
 523                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 524                                         check_rec.rm_offset);
 525                 if (irec.br_blockcount > check_rec.rm_blockcount)
 526                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 527                                         check_rec.rm_offset);
 528                 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 529                         break;
 530                 check_rec.rm_startblock += irec.br_blockcount;
 531                 check_rec.rm_offset += irec.br_blockcount;
 532                 check_rec.rm_blockcount -= irec.br_blockcount;
 533                 if (check_rec.rm_blockcount == 0)
 534                         break;
 535                 have_map = xfs_iext_next_extent(ifp, &sbcri->icur, &irec);
 536                 if (!have_map)
 537                         xchk_fblock_set_corrupt(sc, sbcri->whichfork,
 538                                         check_rec.rm_offset);
 539         }
 540
 541 out:
 542         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 543                 return -ECANCELED;
 544         return 0;
 545 }
 546
 547 /* Make sure each rmap has a corresponding bmbt entry. */
 548 STATIC int
 549 xchk_bmap_check_ag_rmaps(
 550         struct xfs_scrub                *sc,
 551         int                             whichfork,
 552         struct xfs_perag                *pag)
 553 {
 554         struct xchk_bmap_check_rmap_info        sbcri;
 555         struct xfs_btree_cur            *cur;
 556         struct xfs_buf                  *agf;
 557         int                             error;
 558
 559         error = xfs_alloc_read_agf(sc->mp, sc->tp, pag->pag_agno, 0, &agf);
 560         if (error)
 561                 return error;
 562
 563         cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf, pag);
 564
 565         sbcri.sc = sc;
 566         sbcri.whichfork = whichfork;
 567         error = xfs_rmap_query_all(cur, xchk_bmap_check_rmap, &sbcri);
 568         if (error == -ECANCELED)
 569                 error = 0;
 570
 571         xfs_btree_del_cursor(cur, error);
 572         xfs_trans_brelse(sc->tp, agf);
 573         return error;
 574 }
 575
 576 /* Make sure each rmap has a corresponding bmbt entry. */
 577 STATIC int
 578 xchk_bmap_check_rmaps(
 579         struct xfs_scrub        *sc,
 580         int                     whichfork)
 581 {
 582         struct xfs_ifork        *ifp = XFS_IFORK_PTR(sc->ip, whichfork);
 583         struct xfs_perag        *pag;
 584         xfs_agnumber_t          agno;
 585         bool                    zero_size;
 586         int                     error;
 587
 588         if (!xfs_has_rmapbt(sc->mp) ||
 589             whichfork == XFS_COW_FORK ||
 590             (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
 591                 return 0;
 592
 593         /* Don't support realtime rmap checks yet. */
 594         if (XFS_IS_REALTIME_INODE(sc->ip) && whichfork == XFS_DATA_FORK)
 595                 return 0;
 596
 597         ASSERT(XFS_IFORK_PTR(sc->ip, whichfork) != NULL);
 598
 599         /*
 600          * Only do this for complex maps that are in btree format, or for
 601          * situations where we would seem to have a size but zero extents.
 602          * The inode repair code can zap broken iforks, which means we have
 603          * to flag this bmap as corrupt if there are rmaps that need to be
 604          * reattached.
 605          */
 606
 607         if (whichfork == XFS_DATA_FORK)
 608                 zero_size = i_size_read(VFS_I(sc->ip)) == 0;
 609         else
 610                 zero_size = false;
 611
 612         if (ifp->if_format != XFS_DINODE_FMT_BTREE &&
 613             (zero_size || ifp->if_nextents > 0))
 614                 return 0;
 615
 616         for_each_perag(sc->mp, agno, pag) {
 617                 error = xchk_bmap_check_ag_rmaps(sc, whichfork, pag);
 618                 if (error)
 619                         break;
 620                 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 621                         break;
 622         }
 623         if (pag)
 624                 xfs_perag_put(pag);
 625         return error;
 626 }
 627
 628 /*
 629  * Scrub an inode fork's block mappings.
 630  *
 631  * First we scan every record in every btree block, if applicable.
 632  * Then we unconditionally scan the incore extent cache.
 633  */
 634 STATIC int
 635 xchk_bmap(
 636         struct xfs_scrub        *sc,
 637         int                     whichfork)
 638 {
 639         struct xfs_bmbt_irec    irec;
 640         struct xchk_bmap_info   info = { NULL };
 641         struct xfs_mount        *mp = sc->mp;
 642         struct xfs_inode        *ip = sc->ip;
 643         struct xfs_ifork        *ifp = XFS_IFORK_PTR(ip, whichfork);
 644         xfs_fileoff_t           endoff;
 645         struct xfs_iext_cursor  icur;
 646         int                     error = 0;
 647
 648         /* Non-existent forks can be ignored. */
 649         if (!ifp)
 650                 goto out;
 651
 652         info.is_rt = whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip);
 653         info.whichfork = whichfork;
 654         info.is_shared = whichfork == XFS_DATA_FORK && xfs_is_reflink_inode(ip);
 655         info.sc = sc;
 656
 657         switch (whichfork) {
 658         case XFS_COW_FORK:
 659                 /* No CoW forks on non-reflink inodes/filesystems. */
 660                 if (!xfs_is_reflink_inode(ip)) {
 661                         xchk_ino_set_corrupt(sc, sc->ip->i_ino);
 662                         goto out;
 663                 }
 664                 break;
 665         case XFS_ATTR_FORK:
 666                 if (!xfs_has_attr(mp) && !xfs_has_attr2(mp))
 667                         xchk_ino_set_corrupt(sc, sc->ip->i_ino);
 668                 break;
 669         default:
 670                 ASSERT(whichfork == XFS_DATA_FORK);
 671                 break;
 672         }
 673
 674         /* Check the fork values */
 675         switch (ifp->if_format) {
 676         case XFS_DINODE_FMT_UUID:
 677         case XFS_DINODE_FMT_DEV:
 678         case XFS_DINODE_FMT_LOCAL:
 679                 /* No mappings to check. */
 680                 goto out;
 681         case XFS_DINODE_FMT_EXTENTS:
 682                 break;
 683         case XFS_DINODE_FMT_BTREE:
 684                 if (whichfork == XFS_COW_FORK) {
 685                         xchk_fblock_set_corrupt(sc, whichfork, 0);
 686                         goto out;
 687                 }
 688
 689                 error = xchk_bmap_btree(sc, whichfork, &info);
 690                 if (error)
 691                         goto out;
 692                 break;
 693         default:
 694                 xchk_fblock_set_corrupt(sc, whichfork, 0);
 695                 goto out;
 696         }
 697
 698         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 699                 goto out;
 700
 701         /* Find the offset of the last extent in the mapping. */
 702         error = xfs_bmap_last_offset(ip, &endoff, whichfork);
 703         if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
 704                 goto out;
 705
 706         /* Scrub extent records. */
 707         info.lastoff = 0;
 708         ifp = XFS_IFORK_PTR(ip, whichfork);
 709         for_each_xfs_iext(ifp, &icur, &irec) {
 710                 if (xchk_should_terminate(sc, &error) ||
 711                     (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
 712                         goto out;
 713                 if (isnullstartblock(irec.br_startblock))
 714                         continue;
 715                 if (irec.br_startoff >= endoff) {
 716                         xchk_fblock_set_corrupt(sc, whichfork,
 717                                         irec.br_startoff);
 718                         goto out;
 719                 }
 720                 error = xchk_bmap_iextent(ip, &info, &irec);
 721                 if (error)
 722                         goto out;
 723         }
 724
 725         error = xchk_bmap_check_rmaps(sc, whichfork);
 726         if (!xchk_fblock_xref_process_error(sc, whichfork, 0, &error))
 727                 goto out;
 728 out:
 729         return error;
 730 }
 731
 732 /* Scrub an inode's data fork. */
 733 int
 734 xchk_bmap_data(
 735         struct xfs_scrub        *sc)
 736 {
 737         return xchk_bmap(sc, XFS_DATA_FORK);
 738 }
 739
 740 /* Scrub an inode's attr fork. */
 741 int
 742 xchk_bmap_attr(
 743         struct xfs_scrub        *sc)
 744 {
 745         return xchk_bmap(sc, XFS_ATTR_FORK);
 746 }
 747
 748 /* Scrub an inode's CoW fork. */
 749 int
 750 xchk_bmap_cow(
 751         struct xfs_scrub        *sc)
 752 {
 753         if (!xfs_is_reflink_inode(sc->ip))
 754                 return -ENOENT;
 755
 756         return xchk_bmap(sc, XFS_COW_FORK);
 757 }