[PATCH 08/13] xfs/2303: test that data checksums detect data misplacement

[Christoph Hellwig <hch@lst.de>]

Test that data checksums detect data corruption due to misplacement
by changing the backing files for two zones using the zloop driver.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 tests/xfs/2303     | 88 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/xfs/2303.out |  5 +++
 2 files changed, 93 insertions(+)
 create mode 100755 tests/xfs/2303
 create mode 100644 tests/xfs/2303.out

diff --git a/tests/xfs/2303 b/tests/xfs/2303
new file mode 100755
index 000000000000..7f53fdf94bff
--- /dev/null
+++ b/tests/xfs/2303
@@ -0,0 +1,88 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2026 Christoph Hellwig
+#
+# FS QA Test No. 2303
+#
+# Test that data checksums detect data corruption due to misplacement
+# by changing the backing files for two zones using the zloop driver.
+#
+. ./common/preamble
+. ./common/filter
+. ./common/renameat2
+. ./common/zoned
+
+_begin_fstest auto zone quick datacsum
+
+_cleanup()
+{
+	[ -n "$mnt" ] && _unmount $mnt 2>/dev/null
+	[ -n "$loop_dev" ] && _destroy_loop_device $loop_dev
+	_destroy_zloop $zloop_dev
+	cd /
+	rm -rf $loopfile $zloopdir $mnt
+}
+
+_require_test
+_require_renameat2 "exchange"
+_require_loop
+_require_zloop
+# hack to only run for block based file systems
+_require_block_device $SCRATCH_DEV
+
+loopfile="$TEST_DIR/loopfile"
+zloopdir="$TEST_DIR/zloop"
+mnt="$TEST_DIR/mnt"
+
+rm -rf $loopfile $zloopdir $mnt
+mkdir -p $mnt
+truncate -s 1g $loopfile
+
+loop_dev=$(_create_loop_device $loopfile)
+zloop_dev=$(_create_zloop $zloopdir 256 0)
+zloop_id=$(echo $zloop_dev | grep -oE '[0-9]+$')
+
+_try_mkfs_dev $loop_dev -r rtdev=$zloop_dev,csum=crc32c \
+	>> $seqres.full 2>&1 || \
+	_notrun "cannot mkfs filesystem with data checksums"
+_mount $loop_dev -o rtdev=$zloop_dev $mnt
+
+dd if=/dev/urandom of=$mnt/file1 bs=4k count=1 conv=fsync >/dev/null 2>&1
+dd if=/dev/zero of=$mnt/file2 bs=4k count=1 conv=fsync >/dev/null 2>&1
+
+xfs_bmap -v $mnt/file1 >> $seqres.full 2>&1
+xfs_bmap -v $mnt/file2 >> $seqres.full 2>&1
+
+rg1=`xfs_bmap -v $mnt/file1 | head -n 3 | _filter_bmap_gno`
+rg2=`xfs_bmap -v $mnt/file2 | head -n 3 | _filter_bmap_gno`
+if [ "$rg1" == "$rg2" ]; then
+	_fail "both files placed in same RG: $rg1 $rg2"
+fi
+
+zloop_filename1=$(printf "seq-%06u\n" $rg1)
+backing_file1="$zloopdir/$zloop_id/$zloop_filename1"
+zloop_filename2=$(printf "seq-%06u\n" $rg2)
+backing_file2="$zloopdir/$zloop_id/$zloop_filename2"
+
+_unmount $mnt 2>/dev/null
+_destroy_zloop $zloop_dev
+
+# intentionally corrupt data by swapping the two zone files
+ls -i $backing_file1 $backing_file2 >> $seqres.full
+echo "swapping file $backing_file1 and $backing_file2" >> $seqres.full
+$here/src/renameat2 -x $backing_file1 $backing_file2
+ls -i $backing_file1 $backing_file2 >> $seqres.full
+
+zloop_dev=$(_create_zloop $zloopdir 256 0)
+zloop_id=$(echo $zloop_dev | grep -oE '[0-9]+$')
+_mount $loop_dev -o rtdev=$zloop_dev $mnt
+
+# should return an error on buffered read
+echo "Reading file1 using cat - should fail"
+cat $mnt/file1 > /dev/null | _filter_test_dir
+
+# same with direct I/O
+echo "Reading file2 using O_DIRECT - should fail"
+xfs_io -d $mnt/file2 -c 'pread 0 200M' | _filter_test_dir
+
+_exit 0
diff --git a/tests/xfs/2303.out b/tests/xfs/2303.out
new file mode 100644
index 000000000000..fca2c4830e3c
--- /dev/null
+++ b/tests/xfs/2303.out
@@ -0,0 +1,5 @@
+QA output created by 2303
+Reading file1 using cat - should fail
+cat: /mnt/test/mnt/file1: Input/output error
+Reading file2 using O_DIRECT - should fail
+pread: Input/output error
-- 
2.53.0