added reject_qemu_img_info cases

Added two qemu-img lock tests.
To verify it rejects to get information due to image lock.
Signed-off-by: NHaotong Chen <hachen@redhat.com>

qemu/tests/cfg/reject_qemu_img_info.cfg

+- reject_qemu_img_info:
+    only qcow2
+    virt_test_type = qemu
+    kill_vm = yes
+    start_vm = no
+    force_create_image = no
+    type = reject_qemu_img_info
+    variants:
+        - info_snapshot_chain:
+            image_chain = "image1 sn"
+            image_name_sn = "images/sn"
+            image_format_sn = "qcow2"
+            create_snapshot = yes
+            backing_chain = yes
+        - info_running_img:
+            check_image = yes

qemu/tests/reject_qemu_img_info.py

+import logging
+
+from avocado.utils import process
+from virttest import data_dir
+from virttest import error_context
+from virttest.qemu_storage import QemuImg
+
+from qemu.tests.qemu_disk_img import QemuImgTest
+from qemu.tests.qemu_disk_img import generate_base_snapshot_pair
+
+
+@error_context.context_aware
+def run(test, params, env):
+    """
+    'qemu-img' lock tests.
+
+    Verify it rejects to get information due to image lock.
+    Including two tests:
+    1. Create a base qcow2 image.
+       Create an external snapshot.
+       Boot vm using the base.
+       'qemu-info' the snapshot with option "--backing-chain".
+       'qemu-info' the snapshot with option "--backing-chain" and "-U".
+
+    2. Create a base qcow2 image.
+       Boot vm using the base.
+       'qemu-info' the base.
+       'qemu-info' the base with option "-U".
+
+    :param test: Qemu test object
+    :param params: Dictionary with the test parameters
+    :param env: Dictionary with test environment.
+    """
+    def _boot_vm(boot_img):
+        error_context.context("Boot vm with %s." % boot_img, logging.info)
+        vm.params["images"] = boot_img
+        vm.create()
+        vm.verify_alive()
+
+    def _qemu_img_info(info_img, force_share=False):
+        error_context.context("Check qemu-img info with %s." % info_img,
+                              logging.info)
+        img_param = params.object_params(info_img)
+        img = QemuImg(img_param, data_dir.get_data_dir(), info_img)
+        img.info(force_share)
+
+    def _verify_shared_write_lock_err_msg(e, img_tag):
+        error_context.context("Verify qemu-img shared write lock err msg.",
+                              logging.info)
+        img_param = params.object_params(img_tag)
+        img = QemuImg(img_param, data_dir.get_data_dir(), img_tag)
+        msgs = ['Failed to get shared "write" lock',
+                'Is another process using the image?',
+                img.image_filename]
+        if not all(msg in e.result.stderr.decode() for msg in msgs):
+            test.fail("Image lock information is not as expected.")
+
+    def _qemu_img_info_to_verify_image_lock(boot_img, info_img, img_tag):
+        _boot_vm(boot_img)
+        try:
+            _qemu_img_info(info_img)
+        except process.CmdError as e:
+            _verify_shared_write_lock_err_msg(e, img_tag)
+        else:
+            test.fail("The image %s is not locked." % img_tag)
+        try:
+            _qemu_img_info(info_img, True)
+        except process.CmdError:
+            test.fail("qemu-img info %s failed." % info_img)
+
+    vm = env.get_vm(params["main_vm"])
+    if params.get("create_snapshot", "no") == "yes":
+        gen = generate_base_snapshot_pair(params["image_chain"])
+        base, snapshot = next(gen)
+        # workaround to assign system disk's image_name to image_name_image1
+        params["image_name_image1"] = params["image_name"]
+        qit = QemuImgTest(test, params, env, snapshot)
+        qit.create_snapshot()
+
+        _qemu_img_info_to_verify_image_lock(base, snapshot, base)
+    else:
+        _qemu_img_info_to_verify_image_lock("image1", "image1", "image1")