fs/xfs/scrub/dir.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2017 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <[email protected]>
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_trans_resv.h"
  11 #include "xfs_mount.h"
  12 #include "xfs_defer.h"
  13 #include "xfs_btree.h"
  14 #include "xfs_bit.h"
  15 #include "xfs_log_format.h"
  16 #include "xfs_trans.h"
  17 #include "xfs_sb.h"
  18 #include "xfs_inode.h"
  19 #include "xfs_icache.h"
  20 #include "xfs_itable.h"
  21 #include "xfs_da_format.h"
  22 #include "xfs_da_btree.h"
  23 #include "xfs_dir2.h"
  24 #include "xfs_dir2_priv.h"
  25 #include "xfs_ialloc.h"
  26 #include "scrub/xfs_scrub.h"
  27 #include "scrub/scrub.h"
  28 #include "scrub/common.h"
  29 #include "scrub/trace.h"
  30 #include "scrub/dabtree.h"
  31
  32 /* Set us up to scrub directories. */
  33 int
  34 xchk_setup_directory(
  35         struct xfs_scrub        *sc,
  36         struct xfs_inode        *ip)
  37 {
  38         return xchk_setup_inode_contents(sc, ip, 0);
  39 }
  40
  41 /* Directories */
  42
  43 /* Scrub a directory entry. */
  44
  45 struct xchk_dir_ctx {
  46         /* VFS fill-directory iterator */
  47         struct dir_context      dir_iter;
  48
  49         struct xfs_scrub        *sc;
  50 };
  51
  52 /* Check that an inode's mode matches a given DT_ type. */
  53 STATIC int
  54 xchk_dir_check_ftype(
  55         struct xchk_dir_ctx     *sdc,
  56         xfs_fileoff_t           offset,
  57         xfs_ino_t               inum,
  58         int                     dtype)
  59 {
  60         struct xfs_mount        *mp = sdc->sc->mp;
  61         struct xfs_inode        *ip;
  62         int                     ino_dtype;
  63         int                     error = 0;
  64
  65         if (!xfs_sb_version_hasftype(&mp->m_sb)) {
  66                 if (dtype != DT_UNKNOWN && dtype != DT_DIR)
  67                         xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
  68                                         offset);
  69                 goto out;
  70         }
  71
  72         /*
  73          * Grab the inode pointed to by the dirent.  We release the
  74          * inode before we cancel the scrub transaction.  Since we're
  75          * don't know a priori that releasing the inode won't trigger
  76          * eofblocks cleanup (which allocates what would be a nested
  77          * transaction), we can't use DONTCACHE here because DONTCACHE
  78          * inodes can trigger immediate inactive cleanup of the inode.
  79          */
  80         error = xfs_iget(mp, sdc->sc->tp, inum, 0, 0, &ip);
  81         if (!xchk_fblock_xref_process_error(sdc->sc, XFS_DATA_FORK, offset,
  82                         &error))
  83                 goto out;
  84
  85         /* Convert mode to the DT_* values that dir_emit uses. */
  86         ino_dtype = xfs_dir3_get_dtype(mp,
  87                         xfs_mode_to_ftype(VFS_I(ip)->i_mode));
  88         if (ino_dtype != dtype)
  89                 xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
  90         xfs_irele(ip);
  91 out:
  92         return error;
  93 }
  94
  95 /*
  96  * Scrub a single directory entry.
  97  *
  98  * We use the VFS directory iterator (i.e. readdir) to call this
  99  * function for every directory entry in a directory.  Once we're here,
 100  * we check the inode number to make sure it's sane, then we check that
 101  * we can look up this filename.  Finally, we check the ftype.
 102  */
 103 STATIC int
 104 xchk_dir_actor(
 105         struct dir_context      *dir_iter,
 106         const char              *name,
 107         int                     namelen,
 108         loff_t                  pos,
 109         u64                     ino,
 110         unsigned                type)
 111 {
 112         struct xfs_mount        *mp;
 113         struct xfs_inode        *ip;
 114         struct xchk_dir_ctx     *sdc;
 115         struct xfs_name         xname;
 116         xfs_ino_t               lookup_ino;
 117         xfs_dablk_t             offset;
 118         int                     error = 0;
 119
 120         sdc = container_of(dir_iter, struct xchk_dir_ctx, dir_iter);
 121         ip = sdc->sc->ip;
 122         mp = ip->i_mount;
 123         offset = xfs_dir2_db_to_da(mp->m_dir_geo,
 124                         xfs_dir2_dataptr_to_db(mp->m_dir_geo, pos));
 125
 126         /* Does this inode number make sense? */
 127         if (!xfs_verify_dir_ino(mp, ino)) {
 128                 xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
 129                 goto out;
 130         }
 131
 132         /* Does this name make sense? */
 133         if (!xfs_dir2_namecheck(name, namelen)) {
 134                 xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
 135                 goto out;
 136         }
 137
 138         if (!strncmp(".", name, namelen)) {
 139                 /* If this is "." then check that the inum matches the dir. */
 140                 if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR)
 141                         xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
 142                                         offset);
 143                 if (ino != ip->i_ino)
 144                         xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
 145                                         offset);
 146         } else if (!strncmp("..", name, namelen)) {
 147                 /*
 148                  * If this is ".." in the root inode, check that the inum
 149                  * matches this dir.
 150                  */
 151                 if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR)
 152                         xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
 153                                         offset);
 154                 if (ip->i_ino == mp->m_sb.sb_rootino && ino != ip->i_ino)
 155                         xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
 156                                         offset);
 157         }
 158
 159         /* Verify that we can look up this name by hash. */
 160         xname.name = name;
 161         xname.len = namelen;
 162         xname.type = XFS_DIR3_FT_UNKNOWN;
 163
 164         error = xfs_dir_lookup(sdc->sc->tp, ip, &xname, &lookup_ino, NULL);
 165         if (!xchk_fblock_process_error(sdc->sc, XFS_DATA_FORK, offset,
 166                         &error))
 167                 goto out;
 168         if (lookup_ino != ino) {
 169                 xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
 170                 goto out;
 171         }
 172
 173         /* Verify the file type.  This function absorbs error codes. */
 174         error = xchk_dir_check_ftype(sdc, offset, lookup_ino, type);
 175         if (error)
 176                 goto out;
 177 out:
 178         /*
 179          * A negative error code returned here is supposed to cause the
 180          * dir_emit caller (xfs_readdir) to abort the directory iteration
 181          * and return zero to xchk_directory.
 182          */
 183         if (error == 0 && sdc->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 184                 return -EFSCORRUPTED;
 185         return error;
 186 }
 187
 188 /* Scrub a directory btree record. */
 189 STATIC int
 190 xchk_dir_rec(
 191         struct xchk_da_btree            *ds,
 192         int                             level,
 193         void                            *rec)
 194 {
 195         struct xfs_mount                *mp = ds->state->mp;
 196         struct xfs_dir2_leaf_entry      *ent = rec;
 197         struct xfs_inode                *dp = ds->dargs.dp;
 198         struct xfs_dir2_data_entry      *dent;
 199         struct xfs_buf                  *bp;
 200         char                            *p, *endp;
 201         xfs_ino_t                       ino;
 202         xfs_dablk_t                     rec_bno;
 203         xfs_dir2_db_t                   db;
 204         xfs_dir2_data_aoff_t            off;
 205         xfs_dir2_dataptr_t              ptr;
 206         xfs_dahash_t                    calc_hash;
 207         xfs_dahash_t                    hash;
 208         unsigned int                    tag;
 209         int                             error;
 210
 211         /* Check the hash of the entry. */
 212         error = xchk_da_btree_hash(ds, level, &ent->hashval);
 213         if (error)
 214                 goto out;
 215
 216         /* Valid hash pointer? */
 217         ptr = be32_to_cpu(ent->address);
 218         if (ptr == 0)
 219                 return 0;
 220
 221         /* Find the directory entry's location. */
 222         db = xfs_dir2_dataptr_to_db(mp->m_dir_geo, ptr);
 223         off = xfs_dir2_dataptr_to_off(mp->m_dir_geo, ptr);
 224         rec_bno = xfs_dir2_db_to_da(mp->m_dir_geo, db);
 225
 226         if (rec_bno >= mp->m_dir_geo->leafblk) {
 227                 xchk_da_set_corrupt(ds, level);
 228                 goto out;
 229         }
 230         error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno, -2, &bp);
 231         if (!xchk_fblock_process_error(ds->sc, XFS_DATA_FORK, rec_bno,
 232                         &error))
 233                 goto out;
 234         if (!bp) {
 235                 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 236                 goto out;
 237         }
 238         xchk_buffer_recheck(ds->sc, bp);
 239
 240         if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 241                 goto out_relse;
 242
 243         dent = (struct xfs_dir2_data_entry *)(((char *)bp->b_addr) + off);
 244
 245         /* Make sure we got a real directory entry. */
 246         p = (char *)mp->m_dir_inode_ops->data_entry_p(bp->b_addr);
 247         endp = xfs_dir3_data_endp(mp->m_dir_geo, bp->b_addr);
 248         if (!endp) {
 249                 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 250                 goto out_relse;
 251         }
 252         while (p < endp) {
 253                 struct xfs_dir2_data_entry      *dep;
 254                 struct xfs_dir2_data_unused     *dup;
 255
 256                 dup = (struct xfs_dir2_data_unused *)p;
 257                 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
 258                         p += be16_to_cpu(dup->length);
 259                         continue;
 260                 }
 261                 dep = (struct xfs_dir2_data_entry *)p;
 262                 if (dep == dent)
 263                         break;
 264                 p += mp->m_dir_inode_ops->data_entsize(dep->namelen);
 265         }
 266         if (p >= endp) {
 267                 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 268                 goto out_relse;
 269         }
 270
 271         /* Retrieve the entry, sanity check it, and compare hashes. */
 272         ino = be64_to_cpu(dent->inumber);
 273         hash = be32_to_cpu(ent->hashval);
 274         tag = be16_to_cpup(dp->d_ops->data_entry_tag_p(dent));
 275         if (!xfs_verify_dir_ino(mp, ino) || tag != off)
 276                 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 277         if (dent->namelen == 0) {
 278                 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 279                 goto out_relse;
 280         }
 281         calc_hash = xfs_da_hashname(dent->name, dent->namelen);
 282         if (calc_hash != hash)
 283                 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 284
 285 out_relse:
 286         xfs_trans_brelse(ds->dargs.trans, bp);
 287 out:
 288         return error;
 289 }
 290
 291 /*
 292  * Is this unused entry either in the bestfree or smaller than all of
 293  * them?  We've already checked that the bestfrees are sorted longest to
 294  * shortest, and that there aren't any bogus entries.
 295  */
 296 STATIC void
 297 xchk_directory_check_free_entry(
 298         struct xfs_scrub                *sc,
 299         xfs_dablk_t                     lblk,
 300         struct xfs_dir2_data_free       *bf,
 301         struct xfs_dir2_data_unused     *dup)
 302 {
 303         struct xfs_dir2_data_free       *dfp;
 304         unsigned int                    dup_length;
 305
 306         dup_length = be16_to_cpu(dup->length);
 307
 308         /* Unused entry is shorter than any of the bestfrees */
 309         if (dup_length < be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
 310                 return;
 311
 312         for (dfp = &bf[XFS_DIR2_DATA_FD_COUNT - 1]; dfp >= bf; dfp--)
 313                 if (dup_length == be16_to_cpu(dfp->length))
 314                         return;
 315
 316         /* Unused entry should be in the bestfrees but wasn't found. */
 317         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 318 }
 319
 320 /* Check free space info in a directory data block. */
 321 STATIC int
 322 xchk_directory_data_bestfree(
 323         struct xfs_scrub                *sc,
 324         xfs_dablk_t                     lblk,
 325         bool                            is_block)
 326 {
 327         struct xfs_dir2_data_unused     *dup;
 328         struct xfs_dir2_data_free       *dfp;
 329         struct xfs_buf                  *bp;
 330         struct xfs_dir2_data_free       *bf;
 331         struct xfs_mount                *mp = sc->mp;
 332         const struct xfs_dir_ops        *d_ops;
 333         char                            *ptr;
 334         char                            *endptr;
 335         u16                             tag;
 336         unsigned int                    nr_bestfrees = 0;
 337         unsigned int                    nr_frees = 0;
 338         unsigned int                    smallest_bestfree;
 339         int                             newlen;
 340         int                             offset;
 341         int                             error;
 342
 343         d_ops = sc->ip->d_ops;
 344
 345         if (is_block) {
 346                 /* dir block format */
 347                 if (lblk != XFS_B_TO_FSBT(mp, XFS_DIR2_DATA_OFFSET))
 348                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 349                 error = xfs_dir3_block_read(sc->tp, sc->ip, &bp);
 350         } else {
 351                 /* dir data format */
 352                 error = xfs_dir3_data_read(sc->tp, sc->ip, lblk, -1, &bp);
 353         }
 354         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
 355                 goto out;
 356         xchk_buffer_recheck(sc, bp);
 357
 358         /* XXX: Check xfs_dir3_data_hdr.pad is zero once we start setting it. */
 359
 360         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 361                 goto out_buf;
 362
 363         /* Do the bestfrees correspond to actual free space? */
 364         bf = d_ops->data_bestfree_p(bp->b_addr);
 365         smallest_bestfree = UINT_MAX;
 366         for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
 367                 offset = be16_to_cpu(dfp->offset);
 368                 if (offset == 0)
 369                         continue;
 370                 if (offset >= mp->m_dir_geo->blksize) {
 371                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 372                         goto out_buf;
 373                 }
 374                 dup = (struct xfs_dir2_data_unused *)(bp->b_addr + offset);
 375                 tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
 376
 377                 /* bestfree doesn't match the entry it points at? */
 378                 if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG) ||
 379                     be16_to_cpu(dup->length) != be16_to_cpu(dfp->length) ||
 380                     tag != ((char *)dup - (char *)bp->b_addr)) {
 381                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 382                         goto out_buf;
 383                 }
 384
 385                 /* bestfree records should be ordered largest to smallest */
 386                 if (smallest_bestfree < be16_to_cpu(dfp->length)) {
 387                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 388                         goto out_buf;
 389                 }
 390
 391                 smallest_bestfree = be16_to_cpu(dfp->length);
 392                 nr_bestfrees++;
 393         }
 394
 395         /* Make sure the bestfrees are actually the best free spaces. */
 396         ptr = (char *)d_ops->data_entry_p(bp->b_addr);
 397         endptr = xfs_dir3_data_endp(mp->m_dir_geo, bp->b_addr);
 398
 399         /* Iterate the entries, stopping when we hit or go past the end. */
 400         while (ptr < endptr) {
 401                 dup = (struct xfs_dir2_data_unused *)ptr;
 402                 /* Skip real entries */
 403                 if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) {
 404                         struct xfs_dir2_data_entry      *dep;
 405
 406                         dep = (struct xfs_dir2_data_entry *)ptr;
 407                         newlen = d_ops->data_entsize(dep->namelen);
 408                         if (newlen <= 0) {
 409                                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
 410                                                 lblk);
 411                                 goto out_buf;
 412                         }
 413                         ptr += newlen;
 414                         continue;
 415                 }
 416
 417                 /* Spot check this free entry */
 418                 tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
 419                 if (tag != ((char *)dup - (char *)bp->b_addr)) {
 420                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 421                         goto out_buf;
 422                 }
 423
 424                 /*
 425                  * Either this entry is a bestfree or it's smaller than
 426                  * any of the bestfrees.
 427                  */
 428                 xchk_directory_check_free_entry(sc, lblk, bf, dup);
 429                 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 430                         goto out_buf;
 431
 432                 /* Move on. */
 433                 newlen = be16_to_cpu(dup->length);
 434                 if (newlen <= 0) {
 435                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 436                         goto out_buf;
 437                 }
 438                 ptr += newlen;
 439                 if (ptr <= endptr)
 440                         nr_frees++;
 441         }
 442
 443         /* We're required to fill all the space. */
 444         if (ptr != endptr)
 445                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 446
 447         /* Did we see at least as many free slots as there are bestfrees? */
 448         if (nr_frees < nr_bestfrees)
 449                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 450 out_buf:
 451         xfs_trans_brelse(sc->tp, bp);
 452 out:
 453         return error;
 454 }
 455
 456 /*
 457  * Does the free space length in the free space index block ($len) match
 458  * the longest length in the directory data block's bestfree array?
 459  * Assume that we've already checked that the data block's bestfree
 460  * array is in order.
 461  */
 462 STATIC void
 463 xchk_directory_check_freesp(
 464         struct xfs_scrub                *sc,
 465         xfs_dablk_t                     lblk,
 466         struct xfs_buf                  *dbp,
 467         unsigned int                    len)
 468 {
 469         struct xfs_dir2_data_free       *dfp;
 470
 471         dfp = sc->ip->d_ops->data_bestfree_p(dbp->b_addr);
 472
 473         if (len != be16_to_cpu(dfp->length))
 474                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 475
 476         if (len > 0 && be16_to_cpu(dfp->offset) == 0)
 477                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 478 }
 479
 480 /* Check free space info in a directory leaf1 block. */
 481 STATIC int
 482 xchk_directory_leaf1_bestfree(
 483         struct xfs_scrub                *sc,
 484         struct xfs_da_args              *args,
 485         xfs_dablk_t                     lblk)
 486 {
 487         struct xfs_dir3_icleaf_hdr      leafhdr;
 488         struct xfs_dir2_leaf_entry      *ents;
 489         struct xfs_dir2_leaf_tail       *ltp;
 490         struct xfs_dir2_leaf            *leaf;
 491         struct xfs_buf                  *dbp;
 492         struct xfs_buf                  *bp;
 493         const struct xfs_dir_ops        *d_ops = sc->ip->d_ops;
 494         struct xfs_da_geometry          *geo = sc->mp->m_dir_geo;
 495         __be16                          *bestp;
 496         __u16                           best;
 497         __u32                           hash;
 498         __u32                           lasthash = 0;
 499         __u32                           bestcount;
 500         unsigned int                    stale = 0;
 501         int                             i;
 502         int                             error;
 503
 504         /* Read the free space block. */
 505         error = xfs_dir3_leaf_read(sc->tp, sc->ip, lblk, -1, &bp);
 506         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
 507                 goto out;
 508         xchk_buffer_recheck(sc, bp);
 509
 510         leaf = bp->b_addr;
 511         d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
 512         ents = d_ops->leaf_ents_p(leaf);
 513         ltp = xfs_dir2_leaf_tail_p(geo, leaf);
 514         bestcount = be32_to_cpu(ltp->bestcount);
 515         bestp = xfs_dir2_leaf_bests_p(ltp);
 516
 517         if (xfs_sb_version_hascrc(&sc->mp->m_sb)) {
 518                 struct xfs_dir3_leaf_hdr        *hdr3 = bp->b_addr;
 519
 520                 if (hdr3->pad != cpu_to_be32(0))
 521                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 522         }
 523
 524         /*
 525          * There should be as many bestfree slots as there are dir data
 526          * blocks that can fit under i_size.
 527          */
 528         if (bestcount != xfs_dir2_byte_to_db(geo, sc->ip->i_d.di_size)) {
 529                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 530                 goto out;
 531         }
 532
 533         /* Is the leaf count even remotely sane? */
 534         if (leafhdr.count > d_ops->leaf_max_ents(geo)) {
 535                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 536                 goto out;
 537         }
 538
 539         /* Leaves and bests don't overlap in leaf format. */
 540         if ((char *)&ents[leafhdr.count] > (char *)bestp) {
 541                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 542                 goto out;
 543         }
 544
 545         /* Check hash value order, count stale entries.  */
 546         for (i = 0; i < leafhdr.count; i++) {
 547                 hash = be32_to_cpu(ents[i].hashval);
 548                 if (i > 0 && lasthash > hash)
 549                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 550                 lasthash = hash;
 551                 if (ents[i].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
 552                         stale++;
 553         }
 554         if (leafhdr.stale != stale)
 555                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 556         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 557                 goto out;
 558
 559         /* Check all the bestfree entries. */
 560         for (i = 0; i < bestcount; i++, bestp++) {
 561                 best = be16_to_cpu(*bestp);
 562                 if (best == NULLDATAOFF)
 563                         continue;
 564                 error = xfs_dir3_data_read(sc->tp, sc->ip,
 565                                 i * args->geo->fsbcount, -1, &dbp);
 566                 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
 567                                 &error))
 568                         break;
 569                 xchk_directory_check_freesp(sc, lblk, dbp, best);
 570                 xfs_trans_brelse(sc->tp, dbp);
 571                 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 572                         goto out;
 573         }
 574 out:
 575         return error;
 576 }
 577
 578 /* Check free space info in a directory freespace block. */
 579 STATIC int
 580 xchk_directory_free_bestfree(
 581         struct xfs_scrub                *sc,
 582         struct xfs_da_args              *args,
 583         xfs_dablk_t                     lblk)
 584 {
 585         struct xfs_dir3_icfree_hdr      freehdr;
 586         struct xfs_buf                  *dbp;
 587         struct xfs_buf                  *bp;
 588         __be16                          *bestp;
 589         __u16                           best;
 590         unsigned int                    stale = 0;
 591         int                             i;
 592         int                             error;
 593
 594         /* Read the free space block */
 595         error = xfs_dir2_free_read(sc->tp, sc->ip, lblk, &bp);
 596         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
 597                 goto out;
 598         xchk_buffer_recheck(sc, bp);
 599
 600         if (xfs_sb_version_hascrc(&sc->mp->m_sb)) {
 601                 struct xfs_dir3_free_hdr        *hdr3 = bp->b_addr;
 602
 603                 if (hdr3->pad != cpu_to_be32(0))
 604                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 605         }
 606
 607         /* Check all the entries. */
 608         sc->ip->d_ops->free_hdr_from_disk(&freehdr, bp->b_addr);
 609         bestp = sc->ip->d_ops->free_bests_p(bp->b_addr);
 610         for (i = 0; i < freehdr.nvalid; i++, bestp++) {
 611                 best = be16_to_cpu(*bestp);
 612                 if (best == NULLDATAOFF) {
 613                         stale++;
 614                         continue;
 615                 }
 616                 error = xfs_dir3_data_read(sc->tp, sc->ip,
 617                                 (freehdr.firstdb + i) * args->geo->fsbcount,
 618                                 -1, &dbp);
 619                 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
 620                                 &error))
 621                         break;
 622                 xchk_directory_check_freesp(sc, lblk, dbp, best);
 623                 xfs_trans_brelse(sc->tp, dbp);
 624         }
 625
 626         if (freehdr.nused + stale != freehdr.nvalid)
 627                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 628 out:
 629         return error;
 630 }
 631
 632 /* Check free space information in directories. */
 633 STATIC int
 634 xchk_directory_blocks(
 635         struct xfs_scrub        *sc)
 636 {
 637         struct xfs_bmbt_irec    got;
 638         struct xfs_da_args      args;
 639         struct xfs_ifork        *ifp;
 640         struct xfs_mount        *mp = sc->mp;
 641         xfs_fileoff_t           leaf_lblk;
 642         xfs_fileoff_t           free_lblk;
 643         xfs_fileoff_t           lblk;
 644         struct xfs_iext_cursor  icur;
 645         xfs_dablk_t             dabno;
 646         bool                    found;
 647         int                     is_block = 0;
 648         int                     error;
 649
 650         /* Ignore local format directories. */
 651         if (sc->ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
 652             sc->ip->i_d.di_format != XFS_DINODE_FMT_BTREE)
 653                 return 0;
 654
 655         ifp = XFS_IFORK_PTR(sc->ip, XFS_DATA_FORK);
 656         lblk = XFS_B_TO_FSB(mp, XFS_DIR2_DATA_OFFSET);
 657         leaf_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_LEAF_OFFSET);
 658         free_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_FREE_OFFSET);
 659
 660         /* Is this a block dir? */
 661         args.dp = sc->ip;
 662         args.geo = mp->m_dir_geo;
 663         args.trans = sc->tp;
 664         error = xfs_dir2_isblock(&args, &is_block);
 665         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
 666                 goto out;
 667
 668         /* Iterate all the data extents in the directory... */
 669         found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
 670         while (found && !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
 671                 /* Block directories only have a single block at offset 0. */
 672                 if (is_block &&
 673                     (got.br_startoff > 0 ||
 674                      got.br_blockcount != args.geo->fsbcount)) {
 675                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
 676                                         got.br_startoff);
 677                         break;
 678                 }
 679
 680                 /* No more data blocks... */
 681                 if (got.br_startoff >= leaf_lblk)
 682                         break;
 683
 684                 /*
 685                  * Check each data block's bestfree data.
 686                  *
 687                  * Iterate all the fsbcount-aligned block offsets in
 688                  * this directory.  The directory block reading code is
 689                  * smart enough to do its own bmap lookups to handle
 690                  * discontiguous directory blocks.  When we're done
 691                  * with the extent record, re-query the bmap at the
 692                  * next fsbcount-aligned offset to avoid redundant
 693                  * block checks.
 694                  */
 695                 for (lblk = roundup((xfs_dablk_t)got.br_startoff,
 696                                 args.geo->fsbcount);
 697                      lblk < got.br_startoff + got.br_blockcount;
 698                      lblk += args.geo->fsbcount) {
 699                         error = xchk_directory_data_bestfree(sc, lblk,
 700                                         is_block);
 701                         if (error)
 702                                 goto out;
 703                 }
 704                 dabno = got.br_startoff + got.br_blockcount;
 705                 lblk = roundup(dabno, args.geo->fsbcount);
 706                 found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
 707         }
 708
 709         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 710                 goto out;
 711
 712         /* Look for a leaf1 block, which has free info. */
 713         if (xfs_iext_lookup_extent(sc->ip, ifp, leaf_lblk, &icur, &got) &&
 714             got.br_startoff == leaf_lblk &&
 715             got.br_blockcount == args.geo->fsbcount &&
 716             !xfs_iext_next_extent(ifp, &icur, &got)) {
 717                 if (is_block) {
 718                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 719                         goto out;
 720                 }
 721                 error = xchk_directory_leaf1_bestfree(sc, &args,
 722                                 leaf_lblk);
 723                 if (error)
 724                         goto out;
 725         }
 726
 727         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 728                 goto out;
 729
 730         /* Scan for free blocks */
 731         lblk = free_lblk;
 732         found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
 733         while (found && !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
 734                 /*
 735                  * Dirs can't have blocks mapped above 2^32.
 736                  * Single-block dirs shouldn't even be here.
 737                  */
 738                 lblk = got.br_startoff;
 739                 if (lblk & ~0xFFFFFFFFULL) {
 740                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 741                         goto out;
 742                 }
 743                 if (is_block) {
 744                         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 745                         goto out;
 746                 }
 747
 748                 /*
 749                  * Check each dir free block's bestfree data.
 750                  *
 751                  * Iterate all the fsbcount-aligned block offsets in
 752                  * this directory.  The directory block reading code is
 753                  * smart enough to do its own bmap lookups to handle
 754                  * discontiguous directory blocks.  When we're done
 755                  * with the extent record, re-query the bmap at the
 756                  * next fsbcount-aligned offset to avoid redundant
 757                  * block checks.
 758                  */
 759                 for (lblk = roundup((xfs_dablk_t)got.br_startoff,
 760                                 args.geo->fsbcount);
 761                      lblk < got.br_startoff + got.br_blockcount;
 762                      lblk += args.geo->fsbcount) {
 763                         error = xchk_directory_free_bestfree(sc, &args,
 764                                         lblk);
 765                         if (error)
 766                                 goto out;
 767                 }
 768                 dabno = got.br_startoff + got.br_blockcount;
 769                 lblk = roundup(dabno, args.geo->fsbcount);
 770                 found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
 771         }
 772 out:
 773         return error;
 774 }
 775
 776 /* Scrub a whole directory. */
 777 int
 778 xchk_directory(
 779         struct xfs_scrub        *sc)
 780 {
 781         struct xchk_dir_ctx     sdc = {
 782                 .dir_iter.actor = xchk_dir_actor,
 783                 .dir_iter.pos = 0,
 784                 .sc = sc,
 785         };
 786         size_t                  bufsize;
 787         loff_t                  oldpos;
 788         int                     error = 0;
 789
 790         if (!S_ISDIR(VFS_I(sc->ip)->i_mode))
 791                 return -ENOENT;
 792
 793         /* Plausible size? */
 794         if (sc->ip->i_d.di_size < xfs_dir2_sf_hdr_size(0)) {
 795                 xchk_ino_set_corrupt(sc, sc->ip->i_ino);
 796                 goto out;
 797         }
 798
 799         /* Check directory tree structure */
 800         error = xchk_da_btree(sc, XFS_DATA_FORK, xchk_dir_rec, NULL);
 801         if (error)
 802                 return error;
 803
 804         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 805                 return error;
 806
 807         /* Check the freespace. */
 808         error = xchk_directory_blocks(sc);
 809         if (error)
 810                 return error;
 811
 812         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
 813                 return error;
 814
 815         /*
 816          * Check that every dirent we see can also be looked up by hash.
 817          * Userspace usually asks for a 32k buffer, so we will too.
 818          */
 819         bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE,
 820                         sc->ip->i_d.di_size);
 821
 822         /*
 823          * Look up every name in this directory by hash.
 824          *
 825          * Use the xfs_readdir function to call xchk_dir_actor on
 826          * every directory entry in this directory.  In _actor, we check
 827          * the name, inode number, and ftype (if applicable) of the
 828          * entry.  xfs_readdir uses the VFS filldir functions to provide
 829          * iteration context.
 830          *
 831          * The VFS grabs a read or write lock via i_rwsem before it reads
 832          * or writes to a directory.  If we've gotten this far we've
 833          * already obtained IOLOCK_EXCL, which (since 4.10) is the same as
 834          * getting a write lock on i_rwsem.  Therefore, it is safe for us
 835          * to drop the ILOCK here in order to reuse the _readdir and
 836          * _dir_lookup routines, which do their own ILOCK locking.
 837          */
 838         oldpos = 0;
 839         sc->ilock_flags &= ~XFS_ILOCK_EXCL;
 840         xfs_iunlock(sc->ip, XFS_ILOCK_EXCL);
 841         while (true) {
 842                 error = xfs_readdir(sc->tp, sc->ip, &sdc.dir_iter, bufsize);
 843                 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0,
 844                                 &error))
 845                         goto out;
 846                 if (oldpos == sdc.dir_iter.pos)
 847                         break;
 848                 oldpos = sdc.dir_iter.pos;
 849         }
 850
 851 out:
 852         return error;
 853 }