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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0+
 /*
  * Copyright (C) 2017 Oracle.  All Rights Reserved.
  * Author: Darrick J. Wong <darrick.wong@oracle.com>
  */
 #include "xfs.h"
 #include "xfs_fs.h"
 #include "xfs_shared.h"
 #include "xfs_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
 #include "xfs_log_format.h"
 #include "xfs_trans.h"
 #include "xfs_inode.h"
 #include "xfs_icache.h"
 #include "xfs_dir2.h"
 #include "xfs_dir2_priv.h"
 #include "scrub/scrub.h"
 #include "scrub/common.h"
 #include "scrub/dabtree.h"
 
 /* Set us up to scrub directories. */
 int
 xchk_setup_directory(
     struct xfs_scrub    *sc)
 {
     return xchk_setup_inode_contents(sc, 0);
 }
 
 /* Directories */
 
 /* Scrub a directory entry. */
 
 struct xchk_dir_ctx {
     /* VFS fill-directory iterator */
     struct dir_context  dir_iter;
 
     struct xfs_scrub    *sc;
 };
 
 /* Check that an inode's mode matches a given DT_ type. */
 STATIC int
 xchk_dir_check_ftype(
     struct xchk_dir_ctx *sdc,
     xfs_fileoff_t       offset,
     xfs_ino_t       inum,
     int         dtype)
 {
     struct xfs_mount    *mp = sdc->sc->mp;
     struct xfs_inode    *ip;
     int         ino_dtype;
     int         error = 0;
 
     if (!xfs_has_ftype(mp)) {
         if (dtype != DT_UNKNOWN && dtype != DT_DIR)
             xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
                     offset);
         goto out;
     }
 
     /*
      * Grab the inode pointed to by the dirent.  We release the
      * inode before we cancel the scrub transaction.  Since we're
      * don't know a priori that releasing the inode won't trigger
      * eofblocks cleanup (which allocates what would be a nested
      * transaction), we can't use DONTCACHE here because DONTCACHE
      * inodes can trigger immediate inactive cleanup of the inode.
      *
      * If _iget returns -EINVAL or -ENOENT then the child inode number is
      * garbage and the directory is corrupt.  If the _iget returns
      * -EFSCORRUPTED or -EFSBADCRC then the child is corrupt which is a
      *  cross referencing error.  Any other error is an operational error.
      */
     error = xfs_iget(mp, sdc->sc->tp, inum, 0, 0, &ip);
     if (error == -EINVAL || error == -ENOENT) {
         error = -EFSCORRUPTED;
         xchk_fblock_process_error(sdc->sc, XFS_DATA_FORK, 0, &error);
         goto out;
     }
     if (!xchk_fblock_xref_process_error(sdc->sc, XFS_DATA_FORK, offset,
             &error))
         goto out;
 
     /* Convert mode to the DT_* values that dir_emit uses. */
     ino_dtype = xfs_dir3_get_dtype(mp,
             xfs_mode_to_ftype(VFS_I(ip)->i_mode));
     if (ino_dtype != dtype)
         xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
     xfs_irele(ip);
 out:
     return error;
 }
 
 /*
  * Scrub a single directory entry.
  *
  * We use the VFS directory iterator (i.e. readdir) to call this
  * function for every directory entry in a directory.  Once we're here,
  * we check the inode number to make sure it's sane, then we check that
  * we can look up this filename.  Finally, we check the ftype.
  */
 STATIC int
 xchk_dir_actor(
     struct dir_context  *dir_iter,
     const char      *name,
     int         namelen,
     loff_t          pos,
     u64         ino,
     unsigned        type)
 {
     struct xfs_mount    *mp;
     struct xfs_inode    *ip;
     struct xchk_dir_ctx *sdc;
     struct xfs_name     xname;
     xfs_ino_t       lookup_ino;
     xfs_dablk_t     offset;
     bool            checked_ftype = false;
     int         error = 0;
 
     sdc = container_of(dir_iter, struct xchk_dir_ctx, dir_iter);
     ip = sdc->sc->ip;
     mp = ip->i_mount;
     offset = xfs_dir2_db_to_da(mp->m_dir_geo,
             xfs_dir2_dataptr_to_db(mp->m_dir_geo, pos));
 
     if (xchk_should_terminate(sdc->sc, &error))
         return error;
 
     /* Does this inode number make sense? */
     if (!xfs_verify_dir_ino(mp, ino)) {
         xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
         goto out;
     }
 
     /* Does this name make sense? */
     if (!xfs_dir2_namecheck(name, namelen)) {
         xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
         goto out;
     }
 
     if (!strncmp(".", name, namelen)) {
         /* If this is "." then check that the inum matches the dir. */
         if (xfs_has_ftype(mp) && type != DT_DIR)
             xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
                     offset);
         checked_ftype = true;
         if (ino != ip->i_ino)
             xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
                     offset);
     } else if (!strncmp("..", name, namelen)) {
         /*
          * If this is ".." in the root inode, check that the inum
          * matches this dir.
          */
         if (xfs_has_ftype(mp) && type != DT_DIR)
             xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
                     offset);
         checked_ftype = true;
         if (ip->i_ino == mp->m_sb.sb_rootino && ino != ip->i_ino)
             xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
                     offset);
     }
 
     /* Verify that we can look up this name by hash. */
     xname.name = name;
     xname.len = namelen;
     xname.type = XFS_DIR3_FT_UNKNOWN;
 
     error = xfs_dir_lookup(sdc->sc->tp, ip, &xname, &lookup_ino, NULL);
     /* ENOENT means the hash lookup failed and the dir is corrupt */
     if (error == -ENOENT)
         error = -EFSCORRUPTED;
     if (!xchk_fblock_process_error(sdc->sc, XFS_DATA_FORK, offset,
             &error))
         goto out;
     if (lookup_ino != ino) {
         xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK, offset);
         goto out;
     }
 
     /* Verify the file type.  This function absorbs error codes. */
     if (!checked_ftype) {
         error = xchk_dir_check_ftype(sdc, offset, lookup_ino, type);
         if (error)
             goto out;
     }
 out:
     /*
      * A negative error code returned here is supposed to cause the
      * dir_emit caller (xfs_readdir) to abort the directory iteration
      * and return zero to xchk_directory.
      */
     if (error == 0 && sdc->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
         return -EFSCORRUPTED;
     return error;
 }
 
 /* Scrub a directory btree record. */
 STATIC int
 xchk_dir_rec(
     struct xchk_da_btree        *ds,
     int             level)
 {
     struct xfs_da_state_blk     *blk = &ds->state->path.blk[level];
     struct xfs_mount        *mp = ds->state->mp;
     struct xfs_inode        *dp = ds->dargs.dp;
     struct xfs_da_geometry      *geo = mp->m_dir_geo;
     struct xfs_dir2_data_entry  *dent;
     struct xfs_buf          *bp;
     struct xfs_dir2_leaf_entry  *ent;
     unsigned int            end;
     unsigned int            iter_off;
     xfs_ino_t           ino;
     xfs_dablk_t         rec_bno;
     xfs_dir2_db_t           db;
     xfs_dir2_data_aoff_t        off;
     xfs_dir2_dataptr_t      ptr;
     xfs_dahash_t            calc_hash;
     xfs_dahash_t            hash;
     struct xfs_dir3_icleaf_hdr  hdr;
     unsigned int            tag;
     int             error;
 
     ASSERT(blk->magic == XFS_DIR2_LEAF1_MAGIC ||
            blk->magic == XFS_DIR2_LEAFN_MAGIC);
 
     xfs_dir2_leaf_hdr_from_disk(mp, &hdr, blk->bp->b_addr);
     ent = hdr.ents + blk->index;
 
     /* Check the hash of the entry. */
     error = xchk_da_btree_hash(ds, level, &ent->hashval);
     if (error)
         goto out;
 
     /* Valid hash pointer? */
     ptr = be32_to_cpu(ent->address);
     if (ptr == 0)
         return 0;
 
     /* Find the directory entry's location. */
     db = xfs_dir2_dataptr_to_db(geo, ptr);
     off = xfs_dir2_dataptr_to_off(geo, ptr);
     rec_bno = xfs_dir2_db_to_da(geo, db);
 
     if (rec_bno >= geo->leafblk) {
         xchk_da_set_corrupt(ds, level);
         goto out;
     }
     error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno,
             XFS_DABUF_MAP_HOLE_OK, &bp);
     if (!xchk_fblock_process_error(ds->sc, XFS_DATA_FORK, rec_bno,
             &error))
         goto out;
     if (!bp) {
         xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
         goto out;
     }
     xchk_buffer_recheck(ds->sc, bp);
 
     if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
         goto out_relse;
 
     dent = bp->b_addr + off;
 
     /* Make sure we got a real directory entry. */
     iter_off = geo->data_entry_offset;
     end = xfs_dir3_data_end_offset(geo, bp->b_addr);
     if (!end) {
         xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
         goto out_relse;
     }
     for (;;) {
         struct xfs_dir2_data_entry  *dep = bp->b_addr + iter_off;
         struct xfs_dir2_data_unused *dup = bp->b_addr + iter_off;
 
         if (iter_off >= end) {
             xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
             goto out_relse;
         }
 
         if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
             iter_off += be16_to_cpu(dup->length);
             continue;
         }
         if (dep == dent)
             break;
         iter_off += xfs_dir2_data_entsize(mp, dep->namelen);
     }
 
     /* Retrieve the entry, sanity check it, and compare hashes. */
     ino = be64_to_cpu(dent->inumber);
     hash = be32_to_cpu(ent->hashval);
     tag = be16_to_cpup(xfs_dir2_data_entry_tag_p(mp, dent));
     if (!xfs_verify_dir_ino(mp, ino) || tag != off)
         xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
     if (dent->namelen == 0) {
         xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
         goto out_relse;
     }
     calc_hash = xfs_da_hashname(dent->name, dent->namelen);
     if (calc_hash != hash)
         xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
 
 out_relse:
     xfs_trans_brelse(ds->dargs.trans, bp);
 out:
     return error;
 }
 
 /*
  * Is this unused entry either in the bestfree or smaller than all of
  * them?  We've already checked that the bestfrees are sorted longest to
  * shortest, and that there aren't any bogus entries.
  */
 STATIC void
 xchk_directory_check_free_entry(
     struct xfs_scrub        *sc,
     xfs_dablk_t         lblk,
     struct xfs_dir2_data_free   *bf,
     struct xfs_dir2_data_unused *dup)
 {
     struct xfs_dir2_data_free   *dfp;
     unsigned int            dup_length;
 
     dup_length = be16_to_cpu(dup->length);
 
     /* Unused entry is shorter than any of the bestfrees */
     if (dup_length < be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
         return;
 
     for (dfp = &bf[XFS_DIR2_DATA_FD_COUNT - 1]; dfp >= bf; dfp--)
         if (dup_length == be16_to_cpu(dfp->length))
             return;
 
     /* Unused entry should be in the bestfrees but wasn't found. */
     xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 }
 
 /* Check free space info in a directory data block. */
 STATIC int
 xchk_directory_data_bestfree(
     struct xfs_scrub        *sc,
     xfs_dablk_t         lblk,
     bool                is_block)
 {
     struct xfs_dir2_data_unused *dup;
     struct xfs_dir2_data_free   *dfp;
     struct xfs_buf          *bp;
     struct xfs_dir2_data_free   *bf;
     struct xfs_mount        *mp = sc->mp;
     u16             tag;
     unsigned int            nr_bestfrees = 0;
     unsigned int            nr_frees = 0;
     unsigned int            smallest_bestfree;
     int             newlen;
     unsigned int            offset;
     unsigned int            end;
     int             error;
 
     if (is_block) {
         /* dir block format */
         if (lblk != XFS_B_TO_FSBT(mp, XFS_DIR2_DATA_OFFSET))
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
         error = xfs_dir3_block_read(sc->tp, sc->ip, &bp);
     } else {
         /* dir data format */
         error = xfs_dir3_data_read(sc->tp, sc->ip, lblk, 0, &bp);
     }
     if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
         goto out;
     xchk_buffer_recheck(sc, bp);
 
     /* XXX: Check xfs_dir3_data_hdr.pad is zero once we start setting it. */
 
     if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
         goto out_buf;
 
     /* Do the bestfrees correspond to actual free space? */
     bf = xfs_dir2_data_bestfree_p(mp, bp->b_addr);
     smallest_bestfree = UINT_MAX;
     for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
         offset = be16_to_cpu(dfp->offset);
         if (offset == 0)
             continue;
         if (offset >= mp->m_dir_geo->blksize) {
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
             goto out_buf;
         }
         dup = bp->b_addr + offset;
         tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
 
         /* bestfree doesn't match the entry it points at? */
         if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG) ||
             be16_to_cpu(dup->length) != be16_to_cpu(dfp->length) ||
             tag != offset) {
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
             goto out_buf;
         }
 
         /* bestfree records should be ordered largest to smallest */
         if (smallest_bestfree < be16_to_cpu(dfp->length)) {
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
             goto out_buf;
         }
 
         smallest_bestfree = be16_to_cpu(dfp->length);
         nr_bestfrees++;
     }
 
     /* Make sure the bestfrees are actually the best free spaces. */
     offset = mp->m_dir_geo->data_entry_offset;
     end = xfs_dir3_data_end_offset(mp->m_dir_geo, bp->b_addr);
 
     /* Iterate the entries, stopping when we hit or go past the end. */
     while (offset < end) {
         dup = bp->b_addr + offset;
 
         /* Skip real entries */
         if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) {
             struct xfs_dir2_data_entry *dep = bp->b_addr + offset;
 
             newlen = xfs_dir2_data_entsize(mp, dep->namelen);
             if (newlen <= 0) {
                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
                         lblk);
                 goto out_buf;
             }
             offset += newlen;
             continue;
         }
 
         /* Spot check this free entry */
         tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
         if (tag != offset) {
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
             goto out_buf;
         }
 
         /*
          * Either this entry is a bestfree or it's smaller than
          * any of the bestfrees.
          */
         xchk_directory_check_free_entry(sc, lblk, bf, dup);
         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
             goto out_buf;
 
         /* Move on. */
         newlen = be16_to_cpu(dup->length);
         if (newlen <= 0) {
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
             goto out_buf;
         }
         offset += newlen;
         if (offset <= end)
             nr_frees++;
     }
 
     /* We're required to fill all the space. */
     if (offset != end)
         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 
     /* Did we see at least as many free slots as there are bestfrees? */
     if (nr_frees < nr_bestfrees)
         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 out_buf:
     xfs_trans_brelse(sc->tp, bp);
 out:
     return error;
 }
 
 /*
  * Does the free space length in the free space index block ($len) match
  * the longest length in the directory data block's bestfree array?
  * Assume that we've already checked that the data block's bestfree
  * array is in order.
  */
 STATIC void
 xchk_directory_check_freesp(
     struct xfs_scrub        *sc,
     xfs_dablk_t         lblk,
     struct xfs_buf          *dbp,
     unsigned int            len)
 {
     struct xfs_dir2_data_free   *dfp;
 
     dfp = xfs_dir2_data_bestfree_p(sc->mp, dbp->b_addr);
 
     if (len != be16_to_cpu(dfp->length))
         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 
     if (len > 0 && be16_to_cpu(dfp->offset) == 0)
         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 }
 
 /* Check free space info in a directory leaf1 block. */
 STATIC int
 xchk_directory_leaf1_bestfree(
     struct xfs_scrub        *sc,
     struct xfs_da_args      *args,
     xfs_dir2_db_t           last_data_db,
     xfs_dablk_t         lblk)
 {
     struct xfs_dir3_icleaf_hdr  leafhdr;
     struct xfs_dir2_leaf_tail   *ltp;
     struct xfs_dir2_leaf        *leaf;
     struct xfs_buf          *dbp;
     struct xfs_buf          *bp;
     struct xfs_da_geometry      *geo = sc->mp->m_dir_geo;
     __be16              *bestp;
     __u16               best;
     __u32               hash;
     __u32               lasthash = 0;
     __u32               bestcount;
     unsigned int            stale = 0;
     int             i;
     int             error;
 
     /* Read the free space block. */
     error = xfs_dir3_leaf_read(sc->tp, sc->ip, lblk, &bp);
     if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
         return error;
     xchk_buffer_recheck(sc, bp);
 
     leaf = bp->b_addr;
     xfs_dir2_leaf_hdr_from_disk(sc->ip->i_mount, &leafhdr, leaf);
     ltp = xfs_dir2_leaf_tail_p(geo, leaf);
     bestcount = be32_to_cpu(ltp->bestcount);
     bestp = xfs_dir2_leaf_bests_p(ltp);
 
     if (xfs_has_crc(sc->mp)) {
         struct xfs_dir3_leaf_hdr    *hdr3 = bp->b_addr;
 
         if (hdr3->pad != cpu_to_be32(0))
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
     }
 
     /*
      * There must be enough bestfree slots to cover all the directory data
      * blocks that we scanned.  It is possible for there to be a hole
      * between the last data block and i_disk_size.  This seems like an
      * oversight to the scrub author, but as we have been writing out
      * directories like this (and xfs_repair doesn't mind them) for years,
      * that's what we have to check.
      */
     if (bestcount != last_data_db + 1) {
         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
         goto out;
     }
 
     /* Is the leaf count even remotely sane? */
     if (leafhdr.count > geo->leaf_max_ents) {
         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
         goto out;
     }
 
     /* Leaves and bests don't overlap in leaf format. */
     if ((char *)&leafhdr.ents[leafhdr.count] > (char *)bestp) {
         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
         goto out;
     }
 
     /* Check hash value order, count stale entries.  */
     for (i = 0; i < leafhdr.count; i++) {
         hash = be32_to_cpu(leafhdr.ents[i].hashval);
         if (i > 0 && lasthash > hash)
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
         lasthash = hash;
         if (leafhdr.ents[i].address ==
             cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
             stale++;
     }
     if (leafhdr.stale != stale)
         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
     if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
         goto out;
 
     /* Check all the bestfree entries. */
     for (i = 0; i < bestcount; i++, bestp++) {
         best = be16_to_cpu(*bestp);
         error = xfs_dir3_data_read(sc->tp, sc->ip,
                 xfs_dir2_db_to_da(args->geo, i),
                 XFS_DABUF_MAP_HOLE_OK,
                 &dbp);
         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
                 &error))
             break;
 
         if (!dbp) {
             if (best != NULLDATAOFF) {
                 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
                         lblk);
                 break;
             }
             continue;
         }
 
         if (best == NULLDATAOFF)
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
         else
             xchk_directory_check_freesp(sc, lblk, dbp, best);
         xfs_trans_brelse(sc->tp, dbp);
         if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
             break;
     }
 out:
     xfs_trans_brelse(sc->tp, bp);
     return error;
 }
 
 /* Check free space info in a directory freespace block. */
 STATIC int
 xchk_directory_free_bestfree(
     struct xfs_scrub        *sc,
     struct xfs_da_args      *args,
     xfs_dablk_t         lblk)
 {
     struct xfs_dir3_icfree_hdr  freehdr;
     struct xfs_buf          *dbp;
     struct xfs_buf          *bp;
     __u16               best;
     unsigned int            stale = 0;
     int             i;
     int             error;
 
     /* Read the free space block */
     error = xfs_dir2_free_read(sc->tp, sc->ip, lblk, &bp);
     if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
         return error;
     xchk_buffer_recheck(sc, bp);
 
     if (xfs_has_crc(sc->mp)) {
         struct xfs_dir3_free_hdr    *hdr3 = bp->b_addr;
 
         if (hdr3->pad != cpu_to_be32(0))
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
     }
 
     /* Check all the entries. */
     xfs_dir2_free_hdr_from_disk(sc->ip->i_mount, &freehdr, bp->b_addr);
     for (i = 0; i < freehdr.nvalid; i++) {
         best = be16_to_cpu(freehdr.bests[i]);
         if (best == NULLDATAOFF) {
             stale++;
             continue;
         }
         error = xfs_dir3_data_read(sc->tp, sc->ip,
                 (freehdr.firstdb + i) * args->geo->fsbcount,
                 0, &dbp);
         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
                 &error))
             goto out;
         xchk_directory_check_freesp(sc, lblk, dbp, best);
         xfs_trans_brelse(sc->tp, dbp);
     }
 
     if (freehdr.nused + stale != freehdr.nvalid)
         xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
 out:
     xfs_trans_brelse(sc->tp, bp);
     return error;
 }
 
 /* Check free space information in directories. */
 STATIC int
 xchk_directory_blocks(
     struct xfs_scrub    *sc)
 {
     struct xfs_bmbt_irec    got;
     struct xfs_da_args  args;
     struct xfs_ifork    *ifp = xfs_ifork_ptr(sc->ip, XFS_DATA_FORK);
     struct xfs_mount    *mp = sc->mp;
     xfs_fileoff_t       leaf_lblk;
     xfs_fileoff_t       free_lblk;
     xfs_fileoff_t       lblk;
     struct xfs_iext_cursor  icur;
     xfs_dablk_t     dabno;
     xfs_dir2_db_t       last_data_db = 0;
     bool            found;
     int         is_block = 0;
     int         error;
 
     /* Ignore local format directories. */
     if (ifp->if_format != XFS_DINODE_FMT_EXTENTS &&
         ifp->if_format != XFS_DINODE_FMT_BTREE)
         return 0;
 
     lblk = XFS_B_TO_FSB(mp, XFS_DIR2_DATA_OFFSET);
     leaf_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_LEAF_OFFSET);
     free_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_FREE_OFFSET);
 
     /* Is this a block dir? */
     args.dp = sc->ip;
     args.geo = mp->m_dir_geo;
     args.trans = sc->tp;
     error = xfs_dir2_isblock(&args, &is_block);
     if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
         goto out;
 
     /* Iterate all the data extents in the directory... */
     found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
     while (found && !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
         /* No more data blocks... */
         if (got.br_startoff >= leaf_lblk)
             break;
 
         /*
          * Check each data block's bestfree data.
          *
          * Iterate all the fsbcount-aligned block offsets in
          * this directory.  The directory block reading code is
          * smart enough to do its own bmap lookups to handle
          * discontiguous directory blocks.  When we're done
          * with the extent record, re-query the bmap at the
          * next fsbcount-aligned offset to avoid redundant
          * block checks.
          */
         for (lblk = roundup((xfs_dablk_t)got.br_startoff,
                 args.geo->fsbcount);
              lblk < got.br_startoff + got.br_blockcount;
              lblk += args.geo->fsbcount) {
             last_data_db = xfs_dir2_da_to_db(args.geo, lblk);
             error = xchk_directory_data_bestfree(sc, lblk,
                     is_block);
             if (error)
                 goto out;
         }
         dabno = got.br_startoff + got.br_blockcount;
         lblk = roundup(dabno, args.geo->fsbcount);
         found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
     }
 
     if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
         goto out;
 
     /* Look for a leaf1 block, which has free info. */
     if (xfs_iext_lookup_extent(sc->ip, ifp, leaf_lblk, &icur, &got) &&
         got.br_startoff == leaf_lblk &&
         got.br_blockcount == args.geo->fsbcount &&
         !xfs_iext_next_extent(ifp, &icur, &got)) {
         if (is_block) {
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
             goto out;
         }
         error = xchk_directory_leaf1_bestfree(sc, &args, last_data_db,
                 leaf_lblk);
         if (error)
             goto out;
     }
 
     if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
         goto out;
 
     /* Scan for free blocks */
     lblk = free_lblk;
     found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
     while (found && !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
         /*
          * Dirs can't have blocks mapped above 2^32.
          * Single-block dirs shouldn't even be here.
          */
         lblk = got.br_startoff;
         if (lblk & ~0xFFFFFFFFULL) {
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
             goto out;
         }
         if (is_block) {
             xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
             goto out;
         }
 
         /*
          * Check each dir free block's bestfree data.
          *
          * Iterate all the fsbcount-aligned block offsets in
          * this directory.  The directory block reading code is
          * smart enough to do its own bmap lookups to handle
          * discontiguous directory blocks.  When we're done
          * with the extent record, re-query the bmap at the
          * next fsbcount-aligned offset to avoid redundant
          * block checks.
          */
         for (lblk = roundup((xfs_dablk_t)got.br_startoff,
                 args.geo->fsbcount);
              lblk < got.br_startoff + got.br_blockcount;
              lblk += args.geo->fsbcount) {
             error = xchk_directory_free_bestfree(sc, &args,
                     lblk);
             if (error)
                 goto out;
         }
         dabno = got.br_startoff + got.br_blockcount;
         lblk = roundup(dabno, args.geo->fsbcount);
         found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
     }
 out:
     return error;
 }
 
 /* Scrub a whole directory. */
 int
 xchk_directory(
     struct xfs_scrub    *sc)
 {
     struct xchk_dir_ctx sdc = {
         .dir_iter.actor = xchk_dir_actor,
         .dir_iter.pos = 0,
         .sc = sc,
     };
     size_t          bufsize;
     loff_t          oldpos;
     int         error = 0;
 
     if (!S_ISDIR(VFS_I(sc->ip)->i_mode))
         return -ENOENT;
 
     /* Plausible size? */
     if (sc->ip->i_disk_size < xfs_dir2_sf_hdr_size(0)) {
         xchk_ino_set_corrupt(sc, sc->ip->i_ino);
         goto out;
     }
 
     /* Check directory tree structure */
     error = xchk_da_btree(sc, XFS_DATA_FORK, xchk_dir_rec, NULL);
     if (error)
         return error;
 
     if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
         return error;
 
     /* Check the freespace. */
     error = xchk_directory_blocks(sc);
     if (error)
         return error;
 
     if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
         return error;
 
     /*
      * Check that every dirent we see can also be looked up by hash.
      * Userspace usually asks for a 32k buffer, so we will too.
      */
     bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE,
             sc->ip->i_disk_size);
 
     /*
      * Look up every name in this directory by hash.
      *
      * Use the xfs_readdir function to call xchk_dir_actor on
      * every directory entry in this directory.  In _actor, we check
      * the name, inode number, and ftype (if applicable) of the
      * entry.  xfs_readdir uses the VFS filldir functions to provide
      * iteration context.
      *
      * The VFS grabs a read or write lock via i_rwsem before it reads
      * or writes to a directory.  If we've gotten this far we've
      * already obtained IOLOCK_EXCL, which (since 4.10) is the same as
      * getting a write lock on i_rwsem.  Therefore, it is safe for us
      * to drop the ILOCK here in order to reuse the _readdir and
      * _dir_lookup routines, which do their own ILOCK locking.
      */
     oldpos = 0;
     sc->ilock_flags &= ~XFS_ILOCK_EXCL;
     xfs_iunlock(sc->ip, XFS_ILOCK_EXCL);
     while (true) {
         error = xfs_readdir(sc->tp, sc->ip, &sdc.dir_iter, bufsize);
         if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, 0,
                 &error))
             goto out;
         if (oldpos == sdc.dir_iter.pos)
             break;
         oldpos = sdc.dir_iter.pos;
     }
 
 out:
     return error;
 }

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