Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 850 insertions, 0 deletions

diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
new file mode 100644
index 000000000..33dfcba72
--- /dev/null
+++ b/fs/xfs/scrub/dir.c
@@ -0,0 +1,850 @@
+// 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_defer.h"
+#include "xfs_btree.h"
+#include "xfs_bit.h"
+#include "xfs_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_inode.h"
+#include "xfs_icache.h"
+#include "xfs_itable.h"
+#include "xfs_da_format.h"
+#include "xfs_da_btree.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_ialloc.h"
+#include "scrub/xfs_scrub.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/dabtree.h"
+
+/* Set us up to scrub directories. */
+int
+xchk_setup_directory(
+	struct xfs_scrub	*sc,
+	struct xfs_inode	*ip)
+{
+	return xchk_setup_inode_contents(sc, ip, 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_sb_version_hasftype(&mp->m_sb)) {
+		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.
+	 */
+	error = xfs_iget(mp, sdc->sc->tp, inum, 0, 0, &ip);
+	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;
+	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));
+
+	/* 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;
+	}
+
+	if (!strncmp(".", name, namelen)) {
+		/* If this is "." then check that the inum matches the dir. */
+		if (xfs_sb_version_hasftype(&mp->m_sb) && type != DT_DIR)
+			xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+					offset);
+		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_sb_version_hasftype(&mp->m_sb) && type != DT_DIR)
+			xchk_fblock_set_corrupt(sdc->sc, XFS_DATA_FORK,
+					offset);
+		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. */
+	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,
+	void				*rec)
+{
+	struct xfs_mount		*mp = ds->state->mp;
+	struct xfs_dir2_leaf_entry	*ent = rec;
+	struct xfs_inode		*dp = ds->dargs.dp;
+	struct xfs_dir2_data_entry	*dent;
+	struct xfs_buf			*bp;
+	char				*p, *endp;
+	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;
+	unsigned int			tag;
+	int				error;
+
+	/* 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(mp->m_dir_geo, ptr);
+	off = xfs_dir2_dataptr_to_off(mp->m_dir_geo, ptr);
+	rec_bno = xfs_dir2_db_to_da(mp->m_dir_geo, db);
+
+	if (rec_bno >= mp->m_dir_geo->leafblk) {
+		xchk_da_set_corrupt(ds, level);
+		goto out;
+	}
+	error = xfs_dir3_data_read(ds->dargs.trans, dp, rec_bno, -2, &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 = (struct xfs_dir2_data_entry *)(((char *)bp->b_addr) + off);
+
+	/* Make sure we got a real directory entry. */
+	p = (char *)mp->m_dir_inode_ops->data_entry_p(bp->b_addr);
+	endp = xfs_dir3_data_endp(mp->m_dir_geo, bp->b_addr);
+	if (!endp) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		goto out_relse;
+	}
+	while (p < endp) {
+		struct xfs_dir2_data_entry	*dep;
+		struct xfs_dir2_data_unused	*dup;
+
+		dup = (struct xfs_dir2_data_unused *)p;
+		if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
+			p += be16_to_cpu(dup->length);
+			continue;
+		}
+		dep = (struct xfs_dir2_data_entry *)p;
+		if (dep == dent)
+			break;
+		p += mp->m_dir_inode_ops->data_entsize(dep->namelen);
+	}
+	if (p >= endp) {
+		xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
+		goto out_relse;
+	}
+
+	/* 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(dp->d_ops->data_entry_tag_p(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;
+	const struct xfs_dir_ops	*d_ops;
+	char				*ptr;
+	char				*endptr;
+	u16				tag;
+	unsigned int			nr_bestfrees = 0;
+	unsigned int			nr_frees = 0;
+	unsigned int			smallest_bestfree;
+	int				newlen;
+	int				offset;
+	int				error;
+
+	d_ops = sc->ip->d_ops;
+
+	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, -1, &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 = d_ops->data_bestfree_p(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 = (struct xfs_dir2_data_unused *)(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 != ((char *)dup - (char *)bp->b_addr)) {
+			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. */
+	ptr = (char *)d_ops->data_entry_p(bp->b_addr);
+	endptr = xfs_dir3_data_endp(mp->m_dir_geo, bp->b_addr);
+
+	/* Iterate the entries, stopping when we hit or go past the end. */
+	while (ptr < endptr) {
+		dup = (struct xfs_dir2_data_unused *)ptr;
+		/* Skip real entries */
+		if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) {
+			struct xfs_dir2_data_entry	*dep;
+
+			dep = (struct xfs_dir2_data_entry *)ptr;
+			newlen = d_ops->data_entsize(dep->namelen);
+			if (newlen <= 0) {
+				xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
+						lblk);
+				goto out_buf;
+			}
+			ptr += newlen;
+			continue;
+		}
+
+		/* Spot check this free entry */
+		tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
+		if (tag != ((char *)dup - (char *)bp->b_addr)) {
+			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;
+		}
+		ptr += newlen;
+		if (ptr <= endptr)
+			nr_frees++;
+	}
+
+	/* We're required to fill all the space. */
+	if (ptr != endptr)
+		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 = sc->ip->d_ops->data_bestfree_p(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_dablk_t			lblk)
+{
+	struct xfs_dir3_icleaf_hdr	leafhdr;
+	struct xfs_dir2_leaf_entry	*ents;
+	struct xfs_dir2_leaf_tail	*ltp;
+	struct xfs_dir2_leaf		*leaf;
+	struct xfs_buf			*dbp;
+	struct xfs_buf			*bp;
+	const struct xfs_dir_ops	*d_ops = sc->ip->d_ops;
+	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, -1, &bp);
+	if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
+		goto out;
+	xchk_buffer_recheck(sc, bp);
+
+	leaf = bp->b_addr;
+	d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
+	ents = d_ops->leaf_ents_p(leaf);
+	ltp = xfs_dir2_leaf_tail_p(geo, leaf);
+	bestcount = be32_to_cpu(ltp->bestcount);
+	bestp = xfs_dir2_leaf_bests_p(ltp);
+
+	if (xfs_sb_version_hascrc(&sc->mp->m_sb)) {
+		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 should be as many bestfree slots as there are dir data
+	 * blocks that can fit under i_size.
+	 */
+	if (bestcount != xfs_dir2_byte_to_db(geo, sc->ip->i_d.di_size)) {
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+		goto out;
+	}
+
+	/* Is the leaf count even remotely sane? */
+	if (leafhdr.count > d_ops->leaf_max_ents(geo)) {
+		xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+		goto out;
+	}
+
+	/* Leaves and bests don't overlap in leaf format. */
+	if ((char *)&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(ents[i].hashval);
+		if (i > 0 && lasthash > hash)
+			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
+		lasthash = hash;
+		if (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);
+		if (best == NULLDATAOFF)
+			continue;
+		error = xfs_dir3_data_read(sc->tp, sc->ip,
+				i * args->geo->fsbcount, -1, &dbp);
+		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
+				&error))
+			break;
+		xchk_directory_check_freesp(sc, lblk, dbp, best);
+		xfs_trans_brelse(sc->tp, dbp);
+		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+			goto out;
+	}
+out:
+	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;
+	__be16				*bestp;
+	__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))
+		goto out;
+	xchk_buffer_recheck(sc, bp);
+
+	if (xfs_sb_version_hascrc(&sc->mp->m_sb)) {
+		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. */
+	sc->ip->d_ops->free_hdr_from_disk(&freehdr, bp->b_addr);
+	bestp = sc->ip->d_ops->free_bests_p(bp->b_addr);
+	for (i = 0; i < freehdr.nvalid; i++, bestp++) {
+		best = be16_to_cpu(*bestp);
+		if (best == NULLDATAOFF) {
+			stale++;
+			continue;
+		}
+		error = xfs_dir3_data_read(sc->tp, sc->ip,
+				(freehdr.firstdb + i) * args->geo->fsbcount,
+				-1, &dbp);
+		if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
+				&error))
+			break;
+		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:
+	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;
+	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;
+	bool			found;
+	int			is_block = 0;
+	int			error;
+
+	/* Ignore local format directories. */
+	if (sc->ip->i_d.di_format != XFS_DINODE_FMT_EXTENTS &&
+	    sc->ip->i_d.di_format != XFS_DINODE_FMT_BTREE)
+		return 0;
+
+	ifp = XFS_IFORK_PTR(sc->ip, XFS_DATA_FORK);
+	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)) {
+		/* Block directories only have a single block at offset 0. */
+		if (is_block &&
+		    (got.br_startoff > 0 ||
+		     got.br_blockcount != args.geo->fsbcount)) {
+			xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
+					got.br_startoff);
+			break;
+		}
+
+		/* 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) {
+			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,
+				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_d.di_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_d.di_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;
+}