add inline encryption test

We can check how the module works with blk-crypto-fallback. The blksnap
module should detect I/O units with an encryption context and mark such
snapshots as corrupted. The module should not execute the COW algorithm.

tests/8000-inline-encryption.sh

@@ -0,0 +1,72 @@
+#!/bin/bash -e
+#
+# SPDX-License-Identifier: GPL-2.0+
+
+if [ -z $1 ]
+then
+	DIFF_STORAGE_DIR=${HOME}
+else
+	DIFF_STORAGE_DIR=$1
+fi
+echo "Diff storage directory ${DIFF_STORAGE_DIR}"
+
+. ./functions.sh
+. ./blksnap.sh
+BLOCK_SIZE=$(block_size_mnt ${DIFF_STORAGE_DIR})
+
+echo "---"
+echo "Inline encryption test start"
+echo "devices block size ${BLOCK_SIZE}"
+
+blksnap_load
+blksnap_version
+
+TESTDIR=${HOME}/blksnap-test
+rm -rf ${TESTDIR}
+mkdir -p ${TESTDIR}
+
+MPDIR=/mnt/blksnap-test
+rm -rf ${MPDIR}
+mkdir -p ${MPDIR}
+
+# Create device
+IMAGEFILE_1=${TESTDIR}/simple_1.img
+imagefile_make ${IMAGEFILE_1} 64
+
+DEVICE_1=$(loop_device_attach ${IMAGEFILE_1} ${BLOCK_SIZE})
+mkfs.ext4 -O encrypt ${DEVICE_1}
+echo "new device ${DEVICE_1}"
+
+MOUNTPOINT_1=${MPDIR}/simple_1
+mkdir -p ${MOUNTPOINT_1}
+mount -o inlinecrypt,test_dummy_encryption ${DEVICE_1} ${MOUNTPOINT_1}
+#tune2fs -O encrypt ${DEVICE_1}
+
+generate_files_direct ${MOUNTPOINT_1} "before" 3
+drop_cache
+
+blksnap_snapshot_create "${DEVICE_1}" "${DIFF_STORAGE_DIR}" "64M"
+blksnap_snapshot_take
+
+echo "Write to original"
+generate_files_direct ${MOUNTPOINT_1} "after" 3
+umount ${MOUNTPOINT_1}
+
+echo "Try to read snapshot image"
+DEVICE_IMAGE_1=$(blksnap_get_image ${DEVICE_1})
+set +e
+dd if=${DEVICE_IMAGE_1} of=${TESTDIR}/image1 bs=1KiB oflag=direct status=none
+drop_cache
+set -e
+
+blksnap_snapshot_destroy
+
+echo "Destroy device"
+blksnap_detach ${DEVICE_1}
+loop_device_detach ${DEVICE_1}
+imagefile_cleanup ${IMAGEFILE_1}
+
+blksnap_unload
+
+echo "Inline encryption test finish"
+echo "---"