iotests: add qemu_img_map() function

Add a qemu_img_map() function by analogy with qemu_img_measure(),
qemu_img_check(), and qemu_img_info() that all return JSON information.

Replace calls to qemu_img_pipe('map', '--output=json', ...) with this
new function, which provides better diagnostic information on failure.

Note: The output for iotest 211 changes, because logging JSON after it
was deserialized by Python behaves a little differently than logging the
raw JSON document string itself.
(iotests.log() sorts the keys for Python 3.6 support.)

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20220321201618.903471-11-jsnow@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

tests/qemu-iotests/041

@@ -24,7 +24,7 @@ import os
 import re
 import json
 import iotests
-from iotests import qemu_img, qemu_img_pipe, qemu_io
+from iotests import qemu_img, qemu_img_map, qemu_io
 
 backing_img = os.path.join(iotests.test_dir, 'backing.img')
 target_backing_img = os.path.join(iotests.test_dir, 'target-backing.img')
@@ -1360,8 +1360,7 @@ class TestFilters(iotests.QMPTestCase):
 
         self.vm.qmp('blockdev-del', node_name='target')
 
-        target_map = qemu_img_pipe('map', '--output=json', target_img)
-        target_map = json.loads(target_map)
+        target_map = qemu_img_map(target_img)
 
         assert target_map[0]['start'] == 0
         assert target_map[0]['length'] == 512 * 1024

tests/qemu-iotests/211

@@ -59,7 +59,7 @@ with iotests.FilePath('t.vdi') as disk_path, \
     vm.shutdown()
 
     iotests.img_info_log(disk_path)
-    iotests.log(iotests.qemu_img_pipe('map', '--output=json', disk_path))
+    iotests.log(iotests.qemu_img_map(disk_path))
 
     #
     # Successful image creation (explicit defaults)
@@ -83,7 +83,7 @@ with iotests.FilePath('t.vdi') as disk_path, \
     vm.shutdown()
 
     iotests.img_info_log(disk_path)
-    iotests.log(iotests.qemu_img_pipe('map', '--output=json', disk_path))
+    iotests.log(iotests.qemu_img_map(disk_path))
 
     #
     # Successful image creation (with non-default options)
@@ -107,7 +107,7 @@ with iotests.FilePath('t.vdi') as disk_path, \
     vm.shutdown()
 
     iotests.img_info_log(disk_path)
-    iotests.log(iotests.qemu_img_pipe('map', '--output=json', disk_path))
+    iotests.log(iotests.qemu_img_map(disk_path))
 
     #
     # Invalid BlockdevRef

tests/qemu-iotests/211.out

@@ -17,8 +17,7 @@ file format: IMGFMT
 virtual size: 128 MiB (134217728 bytes)
 cluster_size: 1048576
 
-[{ "start": 0, "length": 134217728, "depth": 0, "present": true, "zero": true, "data": false}]
-
+[{"data": false, "depth": 0, "length": 134217728, "present": true, "start": 0, "zero": true}]
 === Successful image creation (explicit defaults) ===
 
 {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": {"driver": "file", "filename": "TEST_DIR/PID-t.vdi", "size": 0}}}
@@ -36,8 +35,7 @@ file format: IMGFMT
 virtual size: 64 MiB (67108864 bytes)
 cluster_size: 1048576
 
-[{ "start": 0, "length": 67108864, "depth": 0, "present": true, "zero": true, "data": false}]
-
+[{"data": false, "depth": 0, "length": 67108864, "present": true, "start": 0, "zero": true}]
 === Successful image creation (with non-default options) ===
 
 {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": {"driver": "file", "filename": "TEST_DIR/PID-t.vdi", "size": 0}}}
@@ -55,9 +53,7 @@ file format: IMGFMT
 virtual size: 32 MiB (33554432 bytes)
 cluster_size: 1048576
 
-[{ "start": 0, "length": 3072, "depth": 0, "present": true, "zero": false, "data": true, "offset": 1024},
-{ "start": 3072, "length": 33551360, "depth": 0, "present": true, "zero": true, "data": true, "offset": 4096}]
-
+[{"data": true, "depth": 0, "length": 3072, "offset": 1024, "present": true, "start": 0, "zero": false}, {"data": true, "depth": 0, "length": 33551360, "offset": 4096, "present": true, "start": 3072, "zero": true}]
 === Invalid BlockdevRef ===
 
 {"execute": "blockdev-create", "arguments": {"job-id": "job0", "options": {"driver": "vdi", "file": "this doesn't exist", "size": 33554432}}}

tests/qemu-iotests/iotests.py

@@ -318,6 +318,9 @@ def qemu_img_check(*args: str) -> Any:
 def qemu_img_info(*args: str) -> Any:
     return qemu_img_json('info', "--output", "json", *args)
 
+def qemu_img_map(*args: str) -> Any:
+    return qemu_img_json('map', "--output", "json", *args)
+
 def qemu_img_pipe(*args: str) -> str:
     '''Run qemu-img and return its output'''
     return qemu_img_pipe_and_status(*args)[0]

tests/qemu-iotests/tests/block-status-cache

@@ -22,7 +22,7 @@
 import os
 import signal
 import iotests
-from iotests import qemu_img_create, qemu_img_pipe, qemu_nbd
+from iotests import qemu_img_create, qemu_img_map, qemu_nbd
 
 
 image_size = 1 * 1024 * 1024
@@ -76,8 +76,7 @@ class TestBscWithNbd(iotests.QMPTestCase):
         # to allocate the first sector to facilitate alignment probing), and
         # then the rest to be zero.  The BSC will thus contain (if anything)
         # one range covering the first sector.
-        map_pre = qemu_img_pipe('map', '--output=json', '--image-opts',
-                                nbd_img_opts)
+        map_pre = qemu_img_map('--image-opts', nbd_img_opts)
 
         # qemu:allocation-depth maps for want_zero=false.
         # want_zero=false should (with the file driver, which the server is
@@ -111,14 +110,12 @@ class TestBscWithNbd(iotests.QMPTestCase):
         # never loop too many times here.
         for _ in range(2):
             # (Ignore the result, this is just to contaminate the cache)
-            qemu_img_pipe('map', '--output=json', '--image-opts',
-                          nbd_img_opts_alloc_depth)
+            qemu_img_map('--image-opts', nbd_img_opts_alloc_depth)
 
         # Now let's see whether the cache reports everything as data, or
         # whether we get correct information (i.e. the same as we got on our
         # first attempt).
-        map_post = qemu_img_pipe('map', '--output=json', '--image-opts',
-                                 nbd_img_opts)
+        map_post = qemu_img_map('--image-opts', nbd_img_opts)
 
         if map_pre != map_post:
             print('ERROR: Map information differs before and after querying ' +

tests/qemu-iotests/tests/parallels-read-bitmap

@@ -18,9 +18,8 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-import json
 import iotests
-from iotests import qemu_nbd_popen, qemu_img_pipe, log, file_path
+from iotests import qemu_nbd_popen, qemu_img_map, log, file_path
 
 iotests.script_initialize(supported_fmts=['parallels'])
 
@@ -36,8 +35,7 @@ iotests.unarchive_sample_image('parallels-with-bitmap', disk)
 
 with qemu_nbd_popen('--read-only', f'--socket={nbd_sock}',
                     f'--bitmap={bitmap}', '-f', iotests.imgfmt, disk):
-    out = qemu_img_pipe('map', '--output=json', '--image-opts', nbd_opts)
-    chunks = json.loads(out)
+    chunks = qemu_img_map('--image-opts', nbd_opts)
     cluster = 64 * 1024
 
     log('dirty clusters (cluster size is 64K):')