xfs: Check for extent overflow when adding/removing dir entries

This test verifies that XFS does not cause inode fork's extent count to
overflow when adding/removing directory entries.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>

tests/xfs/533

@@ -0,0 +1,182 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2021 Chandan Babu R.  All Rights Reserved.
+#
+# FS QA Test 533
+#
+# Verify that XFS does not cause inode fork's extent count to overflow when
+# adding/removing directory entries.
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+	cd /
+	rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+. ./common/inject
+. ./common/populate
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+_supported_fs xfs
+_require_scratch
+_require_xfs_debug
+_require_test_program "punch-alternating"
+_require_xfs_io_error_injection "reduce_max_iextents"
+_require_xfs_io_error_injection "bmap_alloc_minlen_extent"
+
+_scratch_mkfs_sized $((1024 * 1024 * 1024)) | _filter_mkfs >> $seqres.full 2> $tmp.mkfs
+. $tmp.mkfs
+
+# Filesystems with directory block size greater than one FSB will not be tested,
+# since "7 (i.e. XFS_DA_NODE_MAXDEPTH + 1 data block + 1 free block) * 2 (fsb
+# count) = 14" is greater than the pseudo max extent count limit of 10.
+# Extending the pseudo max limit won't help either.  Consider the case where 1
+# FSB is 1k in size and 1 dir block is 64k in size (i.e. fsb count = 64). In
+# this case, the pseudo max limit has to be greater than 7 * 64 = 448 extents.
+if (( $dirbsize > $dbsize )); then
+	_notrun "Directory block size ($dirbsize) is larger than FSB size ($dbsize)"
+fi
+
+echo "Format and mount fs"
+_scratch_mkfs_sized $((1024 * 1024 * 1024)) >> $seqres.full
+_scratch_mount >> $seqres.full
+
+echo "Consume free space"
+fillerdir=$SCRATCH_MNT/fillerdir
+nr_free_blks=$(stat -f -c '%f' $SCRATCH_MNT)
+nr_free_blks=$((nr_free_blks * 90 / 100))
+
+_fill_fs $((dbsize * nr_free_blks)) $fillerdir $dbsize 0 >> $seqres.full 2>&1
+
+echo "Create fragmented filesystem"
+for dentry in $(ls -1 $fillerdir/); do
+	$here/src/punch-alternating $fillerdir/$dentry >> $seqres.full
+done
+
+echo "Inject reduce_max_iextents error tag"
+_scratch_inject_error reduce_max_iextents 1
+
+echo "Inject bmap_alloc_minlen_extent error tag"
+_scratch_inject_error bmap_alloc_minlen_extent 1
+
+dent_len=255
+
+echo "* Create directory entries"
+
+testdir=$SCRATCH_MNT/testdir
+mkdir $testdir
+
+nr_dents=$((dbsize * 20 / dent_len))
+for i in $(seq 1 $nr_dents); do
+	dentry="$(printf "%0255d" $i)"
+	touch ${testdir}/$dentry >> $seqres.full 2>&1 || break
+done
+
+echo "Verify directory's extent count"
+nextents=$(_xfs_get_fsxattr nextents $testdir)
+if (( $nextents > 10 )); then
+	echo "Extent count overflow check failed: nextents = $nextents"
+	exit 1
+fi
+
+rm -rf $testdir
+
+echo "* Rename: Populate destination directory"
+
+dstdir=$SCRATCH_MNT/dstdir
+mkdir $dstdir
+
+nr_dents=$((dirbsize * 20 / dent_len))
+
+echo "Populate \$dstdir by moving new directory entries"
+for i in $(seq 1 $nr_dents); do
+	dentry="$(printf "%0255d" $i)"
+	dentry=${SCRATCH_MNT}/${dentry}
+	touch $dentry || break
+	mv $dentry $dstdir >> $seqres.full 2>&1 || break
+done
+
+rm $dentry
+
+echo "Verify \$dstdir's extent count"
+
+nextents=$(_xfs_get_fsxattr nextents $dstdir)
+if (( $nextents > 10 )); then
+	echo "Extent count overflow check failed: nextents = $nextents"
+	exit 1
+fi
+
+rm -rf $dstdir
+
+echo "* Create multiple hard links to a single file"
+
+testdir=$SCRATCH_MNT/testdir
+mkdir $testdir
+
+testfile=$SCRATCH_MNT/testfile
+touch $testfile
+
+nr_dents=$((dirbsize * 20 / dent_len))
+
+echo "Create multiple hardlinks"
+for i in $(seq 1 $nr_dents); do
+	dentry="$(printf "%0255d" $i)"
+	ln $testfile ${testdir}/${dentry} >> $seqres.full 2>&1 || break
+done
+
+rm $testfile
+
+echo "Verify directory's extent count"
+nextents=$(_xfs_get_fsxattr nextents $testdir)
+if (( $nextents > 10 )); then
+	echo "Extent count overflow check failed: nextents = $nextents"
+	exit 1
+fi
+
+rm -rf $testdir
+
+echo "* Create multiple symbolic links to a single file"
+
+testdir=$SCRATCH_MNT/testdir
+mkdir $testdir
+
+testfile=$SCRATCH_MNT/testfile
+touch $testfile
+
+nr_dents=$((dirbsize * 20 / dent_len))
+
+echo "Create multiple symbolic links"
+for i in $(seq 1 $nr_dents); do
+	dentry="$(printf "%0255d" $i)"
+	ln -s $testfile ${testdir}/${dentry} >> $seqres.full 2>&1 || break;
+done
+
+rm $testfile
+
+echo "Verify directory's extent count"
+nextents=$(_xfs_get_fsxattr nextents $testdir)
+if (( $nextents > 10 )); then
+	echo "Extent count overflow check failed: nextents = $nextents"
+	exit 1
+fi
+
+rm -rf $testdir
+
+# success, all done
+status=0
+exit

tests/xfs/533.out

@@ -0,0 +1,17 @@
+QA output created by 533
+Format and mount fs
+Consume free space
+Create fragmented filesystem
+Inject reduce_max_iextents error tag
+Inject bmap_alloc_minlen_extent error tag
+* Create directory entries
+Verify directory's extent count
+* Rename: Populate destination directory
+Populate $dstdir by moving new directory entries
+Verify $dstdir's extent count
+* Create multiple hard links to a single file
+Create multiple hardlinks
+Verify directory's extent count
+* Create multiple symbolic links to a single file
+Create multiple symbolic links
+Verify directory's extent count

tests/xfs/group

@@ -509,3 +509,4 @@
 530 auto quick realtime growfs
 531 auto quick punch zero insert collapse
 532 auto quick attr
+533 auto quick dir hardlink symlink