[PATCH 3/3] iotests: add Linux loop device image creation test

[Stefan Hajnoczi <stefanha@redhat.com>]

This qemu-iotests test case is based on the reproducer that Jean-Louis
Dupond <jean-louis@dupond.be> shared in
https://gitlab.com/qemu-project/qemu/-/issues/3127.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 tests/qemu-iotests/tests/loop-create-file     | 59 +++++++++++++++++++
 tests/qemu-iotests/tests/loop-create-file.out |  8 +++
 2 files changed, 67 insertions(+)
 create mode 100755 tests/qemu-iotests/tests/loop-create-file
 create mode 100644 tests/qemu-iotests/tests/loop-create-file.out

diff --git a/tests/qemu-iotests/tests/loop-create-file b/tests/qemu-iotests/tests/loop-create-file
new file mode 100755
index 0000000000..5ec75b046b
--- /dev/null
+++ b/tests/qemu-iotests/tests/loop-create-file
@@ -0,0 +1,59 @@
+#!/usr/bin/env bash
+# group: quick
+#
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright Red Hat, Inc.
+#
+# Test Linux loop device image creation
+#
+# This test verifies #3127 "qemu-img create fails on loop device with sector size 4096"
+# https://gitlab.com/qemu-project/qemu/-/issues/3127
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+status=1	# failure is the default!
+
+_cleanup() {
+    if [ -n "$loopdev" ]; then
+        sudo losetup --detach "$loopdev"
+    fi
+
+    _cleanup_test_img
+}
+
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+cd ..
+. ./common.rc
+. ./common.filter
+
+_supported_fmt raw
+_supported_proto file
+_supported_os Linux
+
+if ! sudo -n losetup &>/dev/null; then
+    _notrun "sudo losetup not available"
+fi
+
+echo
+echo "=== Create image on a 4 KB sector size loop device ==="
+echo
+
+_make_test_img -f $IMGFMT 1M
+
+loopdev=$(sudo losetup --sector-size 4096 --find --show "$TEST_IMG")
+if [ -z "$loopdev" ]; then
+    _fail
+fi
+
+sudo $QEMU_IMG_PROG create -f raw "$loopdev" 1M | \
+    sed -e "s#/dev/loop[0-9]\\+#LOOPDEV#g"
+
+# success, all done
+echo
+echo '*** done'
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/tests/loop-create-file.out b/tests/qemu-iotests/tests/loop-create-file.out
new file mode 100644
index 0000000000..32d4155695
--- /dev/null
+++ b/tests/qemu-iotests/tests/loop-create-file.out
@@ -0,0 +1,8 @@
+QA output created by loop-create-file
+
+=== Create image on a 4 KB sector size loop device ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=1048576
+Formatting 'LOOPDEV', fmt=raw size=1048576
+
+*** done
-- 
2.51.0