qemu-iotest: Test NBD hole reporting for qcow2

diff --git a/tests/qemu-iotests/314 b/tests/qemu-iotests/314
new file mode 100755
index 0000000000..81c0169eac
--- /dev/null
+++ b/tests/qemu-iotests/314
@@ -0,0 +1,96 @@ 
+#!/usr/bin/env bash
+# group: rw quick
+#
+# Test qemu-nbd base:allocation metacontext
+#
+# Copyright (C) 2021 Nir Soffer <nirsof@gmail.com>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# owner=nirsof@gmail.com
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+status=1 # failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+    rm -f "$TEST_DIR/server.log"
+    nbd_server_stop
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+. ./common.nbd
+
+_supported_fmt qcow2
+_supported_proto nbd
+_supported_os Linux
+_require_command QEMU_NBD
+
+TEST_IMG="nbd+unix:///?socket=$nbd_unix_socket"
+
+echo
+echo "=== Single image ==="
+echo
+
+$QEMU_IMG create -f "$IMGFMT" -o cluster_size=64k \
+    "$TEST_IMG_FILE" 384k | _filter_img_create_filenames
+
+$QEMU_IO -f $IMGFMT -c "write -P 1 0k 64k" "$TEST_IMG_FILE" | _filter_qemu_io
+$QEMU_IO -f $IMGFMT -c "write -P 2 64k 512" "$TEST_IMG_FILE" | _filter_qemu_io
+$QEMU_IO -f $IMGFMT -c "write -z 192k 64k" "$TEST_IMG_FILE" | _filter_qemu_io
+$QEMU_IO -f $IMGFMT -c "write -z 256k 512" "$TEST_IMG_FILE" | _filter_qemu_io
+
+nbd_server_start_unix_socket -f $IMGFMT "$TEST_IMG_FILE"
+
+echo
+$QEMU_NBD_PROG --list -k $nbd_unix_socket >/dev/null
+$QEMU_IMG map -f raw --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+nbd_server_stop
+
+echo
+echo "=== Image with backing file ==="
+echo
+
+$QEMU_IMG create -f "$IMGFMT" -o cluster_size=64k \
+    "$TEST_IMG_FILE.base" 384k | _filter_img_create_filenames
+
+$QEMU_IO -f $IMGFMT -c "write -P 1 0k 64k" "$TEST_IMG_FILE.base" | _filter_qemu_io
+$QEMU_IO -f $IMGFMT -c "write -P 2 64k 512" "$TEST_IMG_FILE.base" | _filter_qemu_io
+
+$QEMU_IMG create -f "$IMGFMT" -o cluster_size=64k \
+    -b "$TEST_IMG_FILE.base" -F $IMGFMT "$TEST_IMG_FILE" | _filter_img_create_filenames
+
+$QEMU_IO -f $IMGFMT -c "write -z 192k 64k" "$TEST_IMG_FILE" | _filter_qemu_io
+$QEMU_IO -f $IMGFMT -c "write -z 256k 512" "$TEST_IMG_FILE" | _filter_qemu_io
+
+nbd_server_start_unix_socket -f $IMGFMT "$TEST_IMG_FILE"
+
+echo
+$QEMU_NBD_PROG --list -k $nbd_unix_socket >/dev/null
+$QEMU_IMG map -f raw --output=json "$TEST_IMG" | _filter_qemu_img_map
+
+nbd_server_stop
+
+# success, all done
+echo
+echo '*** done'
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/314.out b/tests/qemu-iotests/314.out
new file mode 100644
index 0000000000..df7eef023f
--- /dev/null
+++ b/tests/qemu-iotests/314.out
@@ -0,0 +1,34 @@ 
+QA output created by 314
+
+=== Single image ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT cluster_size=65536 extended_l2=off compression_type=zlib size=393216 lazy_refcounts=off refcount_bits=16
+wrote 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 65536
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 65536/65536 bytes at offset 196608
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 262144
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+[{ "start": 0, "length": 131072, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
+{ "start": 131072, "length": 262144, "depth": 0, "zero": true, "data": false, "offset": OFFSET}]
+
+=== Image with backing file ===
+
+Formatting 'TEST_DIR/t.IMGFMT.base', fmt=IMGFMT cluster_size=65536 extended_l2=off compression_type=zlib size=393216 lazy_refcounts=off refcount_bits=16
+wrote 65536/65536 bytes at offset 0
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 65536
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT cluster_size=65536 extended_l2=off compression_type=zlib size=393216 backing_file=TEST_DIR/t.IMGFMT.base backing_fmt=IMGFMT lazy_refcounts=off refcount_bits=16
+wrote 65536/65536 bytes at offset 196608
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 512/512 bytes at offset 262144
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+[{ "start": 0, "length": 131072, "depth": 0, "zero": false, "data": true, "offset": OFFSET},
+{ "start": 131072, "length": 262144, "depth": 0, "zero": true, "data": false, "offset": OFFSET}]
+
+*** done
diff --git a/tests/qemu-iotests/common.rc b/tests/qemu-iotests/common.rc
index 7f49c9716d..1dafac6d66 100644
--- a/tests/qemu-iotests/common.rc
+++ b/tests/qemu-iotests/common.rc
@@ -612,6 +612,7 @@  _cleanup_test_img()
         nbd)
             _stop_nbd_server
             rm -f "$TEST_IMG_FILE"
+            rm -f "$TEST_IMG_FILE.base"
             ;;
 
         fuse)