[RFC 9/9] selftests: block_seek_hole: add dm-thin test

[Stefan Hajnoczi <stefanha@redhat.com>]

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 .../selftests/block_seek_hole/Makefile        |  2 +-
 .../selftests/block_seek_hole/dm_thin.sh      | 80 +++++++++++++++++++
 2 files changed, 81 insertions(+), 1 deletion(-)
 create mode 100755 tools/testing/selftests/block_seek_hole/dm_thin.sh

diff --git a/tools/testing/selftests/block_seek_hole/Makefile b/tools/testing/selftests/block_seek_hole/Makefile
index 1bd9e748b2acc..3b4ee1b1fb6e7 100644
--- a/tools/testing/selftests/block_seek_hole/Makefile
+++ b/tools/testing/selftests/block_seek_hole/Makefile
@@ -3,7 +3,7 @@ PY3 = $(shell which python3 2>/dev/null)
 
 ifneq ($(PY3),)
 
-TEST_PROGS := test.py dm_zero.sh
+TEST_PROGS := test.py dm_zero.sh dm_thin.sh
 
 include ../lib.mk
 
diff --git a/tools/testing/selftests/block_seek_hole/dm_thin.sh b/tools/testing/selftests/block_seek_hole/dm_thin.sh
new file mode 100755
index 0000000000000..a379b7c875f28
--- /dev/null
+++ b/tools/testing/selftests/block_seek_hole/dm_thin.sh
@@ -0,0 +1,80 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# dm_thin.sh
+#
+# Test that dm-thin supports SEEK_HOLE/SEEK_DATA.
+
+set -e
+
+# check <actual> <expected>
+# Check that the actual output matches the expected output.
+check() {
+	if [ "$1" != "$2" ]; then
+		echo 'FAIL expected:'
+		echo "$2"
+		echo 'Does not match device output:'
+		echo "$1"
+		exit 1
+	fi
+}
+
+cleanup() {
+	if [ -n "$thin_name" ]; then
+		dmsetup remove $thin_name
+	fi
+	if [ -n "$pool_name" ]; then
+		dmsetup remove $pool_name
+	fi
+	if [ -n "$metadata_path" ]; then
+		losetup --detach "$metadata_path"
+	fi
+	if [ -n "$data_path" ]; then
+		losetup --detach "$data_path"
+	fi
+	rm -f pool-metadata pool-data
+}
+trap cleanup EXIT
+
+rm -f pool-metadata pool-data
+truncate -s 256M pool-metadata
+truncate -s 1G pool-data
+
+size_sectors=$((1024 * 1024 * 1024 / 512)) # 1 GB
+metadata_path=$(losetup --show --find pool-metadata)
+data_path=$(losetup --show --find pool-data)
+pool_name=pool-$$
+thin_name=thin-$$
+
+dmsetup create $pool_name \
+	--table "0 $size_sectors thin-pool $metadata_path $data_path 128 $size_sectors"
+dmsetup message /dev/mapper/$pool_name 0 'create_thin 0'
+dmsetup create $thin_name --table "0 $size_sectors thin /dev/mapper/$pool_name 0"
+
+# Verify that the device is empty
+check "$(./map_holes.py /dev/mapper/$thin_name)" 'TYPE START END SIZE
+HOLE 0 1073741824 1073741824'
+
+# Write 4k at offset 128M but dm-thin will actually map an entire 64k block
+dd if=/dev/urandom of=/dev/mapper/$thin_name bs=4k count=1 seek=32768 status=none
+check "$(./map_holes.py /dev/mapper/$thin_name)" 'TYPE START END SIZE
+HOLE 0 134217728 134217728
+DATA 134217728 134283264 65536
+HOLE 134283264 1073741824 939458560'
+
+# Write at the beginning of the device
+dd if=/dev/urandom of=/dev/mapper/$thin_name bs=4k count=1 status=none
+check "$(./map_holes.py /dev/mapper/$thin_name)" 'TYPE START END SIZE
+DATA 0 65536 65536
+HOLE 65536 134217728 134152192
+DATA 134217728 134283264 65536
+HOLE 134283264 1073741824 939458560'
+
+# Write at the end of the device
+dd if=/dev/urandom of=/dev/mapper/$thin_name bs=4k count=1 seek=262143 status=none
+check "$(./map_holes.py /dev/mapper/$thin_name)" 'TYPE START END SIZE
+DATA 0 65536 65536
+HOLE 65536 134217728 134152192
+DATA 134217728 134283264 65536
+HOLE 134283264 1073676288 939393024
+DATA 1073676288 1073741824 65536'
-- 
2.44.0