1 files changed, 77 insertions, 0 deletions
diff --git a/tests/qemu-iotests/309 b/tests/qemu-iotests/309
new file mode 100755
index 0000000000..fb61157c2e
--- /dev/null
+++ b/tests/qemu-iotests/309
@@ -0,0 +1,77 @@
+#!/usr/bin/env bash
+#
+# Test qemu-nbd -A
+#
+# Copyright (C) 2018-2020 Red Hat, Inc.
+#
+# 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/>.
+#
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+status=1 # failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+    nbd_server_stop
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+. ./common.nbd
+
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+_require_command QEMU_NBD
+
+echo
+echo "=== Initial image setup ==="
+echo
+
+TEST_IMG="$TEST_IMG.base" _make_test_img 4M
+$QEMU_IO -c 'w 0 2M' -f $IMGFMT "$TEST_IMG.base" | _filter_qemu_io
+_make_test_img -b "$TEST_IMG.base" -F $IMGFMT 4M
+$QEMU_IO -c 'w 1M 2M' -f $IMGFMT "$TEST_IMG" | _filter_qemu_io
+
+echo
+echo "=== Check allocation over NBD ==="
+echo
+
+$QEMU_IMG map --output=json -f qcow2 "$TEST_IMG"
+IMG="driver=nbd,server.type=unix,server.path=$nbd_unix_socket"
+nbd_server_start_unix_socket -r -f qcow2 -A "$TEST_IMG"
+# Normal -f raw NBD block status loses access to allocation information
+$QEMU_IMG map --output=json --image-opts \
+    "$IMG" | _filter_qemu_img_map
+# But when we use -A, coupled with x-dirty-bitmap in the client for feeding
+# 2-bit block status from an alternative NBD metadata context (note that
+# the client code for x-dirty-bitmap intentionally collapses all depths
+# beyond 2 into a single value), we can determine:
+#    unallocated (depth 0) => "zero":false, "data":true
+#    local (depth 1)       => "zero":false, "data":false
+#    backing (depth 2+)    => "zero":true,  "data":true
+$QEMU_IMG map --output=json --image-opts \
+    "$IMG,x-dirty-bitmap=qemu:allocation-depth" | _filter_qemu_img_map
+# More accurate results can be obtained by other NBD clients such as
+# libnbd, but this test works without such external dependencies.
+
+# success, all done
+echo '*** done'
+rm -f $seq.full
+status=0