[PATCH 07/13] xfs/2302: add a basic data checksum test

[Christoph Hellwig <hch@lst.de>]

Setup a zoned loop device, mess up the data and make sure both buffered
and direct I/O catch it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 tests/xfs/2302     | 96 ++++++++++++++++++++++++++++++++++++++++++++++
 tests/xfs/2302.out | 25 ++++++++++++
 2 files changed, 121 insertions(+)
 create mode 100755 tests/xfs/2302
 create mode 100644 tests/xfs/2302.out

diff --git a/tests/xfs/2302 b/tests/xfs/2302
new file mode 100755
index 000000000000..d0ef9abc87b0
--- /dev/null
+++ b/tests/xfs/2302
@@ -0,0 +1,96 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2026 Christoph Hellwig
+#
+# FS QA Test No. 2302
+#
+# Test that data checksums detect data corruption using all three bounce
+# buffering modes.
+#
+. ./common/preamble
+. ./common/filter
+. ./common/zoned
+
+_begin_fstest auto zone quick datacsum
+
+cleanup_devices()
+{
+	[ -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
+}
+
+_cleanup()
+{
+	cleanup_devices
+}
+
+_require_test
+_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"
+
+test_error_detection()
+{
+	local bounce_mode=$1
+
+	echo
+	echo
+	echo "Testing bounce mode: $bounce_mode"
+	echo
+
+	rm -rf $loopfile $zloopdir $mnt
+	mkdir -p $mnt
+	truncate -s 1g $loopfile
+
+	local loop_dev=$(_create_loop_device $loopfile)
+	local zloop_dev=$(_create_zloop $zloopdir 256 0)
+	local zloop_id=$(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/file bs=1M count=200 conv=fsync >/dev/null 2>&1
+
+	local rg=`xfs_bmap -v $mnt/file | head -n 3 | _filter_bmap_gno`
+	local zloop_filename=$(printf "seq-%06u\n" $rg)
+	local backing_file="$zloopdir/$zloop_id/$zloop_filename"
+
+	_unmount $mnt 2>/dev/null
+
+	# intentionally corrupt the data on the backing device
+	xfs_io $backing_file -d -c 'pwrite 0 16384' >> $seqres.full 2>&1
+
+	# should return an error on buffered read
+	_mount $loop_dev -o rtdev=$zloop_dev $mnt
+	_set_fs_sysfs_attr $loop_dev csum/read_bounce $bounce_mode
+	echo "Reading file using cat - should fail"
+	cat $mnt/file > /dev/null | _filter_test_dir
+
+	sleep 1
+	_unmount $mnt 2>/dev/null
+
+	# same with direct I/O
+	_mount $loop_dev -o rtdev=$zloop_dev $mnt
+	_set_fs_sysfs_attr $loop_dev csum/read_bounce $bounce_mode
+	echo "Reading file using O_DIRECT - should fail"
+	xfs_io -d $mnt/file -c 'pread 0 200M' | _filter_test_dir
+
+	sleep 1
+	cleanup_devices
+}
+
+test_error_detection "never"
+test_error_detection "always"
+test_error_detection "lazy"
+
+_exit 0
diff --git a/tests/xfs/2302.out b/tests/xfs/2302.out
new file mode 100644
index 000000000000..5e2108b5cec0
--- /dev/null
+++ b/tests/xfs/2302.out
@@ -0,0 +1,25 @@
+QA output created by 2302
+
+
+Testing bounce mode: never
+
+Reading file using cat - should fail
+cat: /mnt/test/mnt/file: Input/output error
+Reading file using O_DIRECT - should fail
+pread: Input/output error
+
+
+Testing bounce mode: always
+
+Reading file using cat - should fail
+cat: /mnt/test/mnt/file: Input/output error
+Reading file using O_DIRECT - should fail
+pread: Input/output error
+
+
+Testing bounce mode: lazy
+
+Reading file using cat - should fail
+cat: /mnt/test/mnt/file: Input/output error
+Reading file using O_DIRECT - should fail
+pread: Input/output error
-- 
2.53.0