1 files changed, 178 insertions, 0 deletions
diff --git a/tests/qemu-iotests/176 b/tests/qemu-iotests/176
new file mode 100755
index 000000000..27ac25467
--- /dev/null
+++ b/tests/qemu-iotests/176
@@ -0,0 +1,178 @@
+#!/usr/bin/env bash
+# group: rw auto backing
+#
+# Commit changes into backing chains and empty the top image if the
+# backing image is not explicitly specified.
+#
+# Variant of 097, which includes snapshots and persistent bitmaps, to
+# tickle the slow codepath in qcow2. See also 198, for another feature
+# that tickles the slow codepath.
+#
+# Copyright (C) 2014, 2017 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/>.
+#
+
+# creator
+owner=mreitz@redhat.com
+
+seq="$(basename $0)"
+echo "QA output created by $seq"
+
+status=1	# failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+    _rm_test_img "$TEST_IMG.itmd"
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+. ./common.pattern
+
+# This test is specific to qcow2
+_supported_fmt qcow2
+_supported_proto file fuse
+_supported_os Linux
+# Persistent dirty bitmaps require compat=1.1;
+# Internal snapshots forbid using an external data file
+# (they work with refcount_bits=1 here, though, because there actually
+# is no data when creating the snapshot)
+_unsupported_imgopts 'compat=0.10' data_file
+
+run_qemu()
+{
+    $QEMU -nographic -qmp stdio -serial none "$@" 2>&1 \
+	| _filter_testdir | _filter_qmp | _filter_qemu \
+        | sed 's/"sha256": ".\{64\}"/"sha256": HASH/'
+}
+
+for reason in snapshot bitmap; do
+
+# Four passes:
+#  0: Two-layer backing chain, commit to upper backing file (implicitly)
+#     (in this case, the top image will be emptied)
+#  1: Two-layer backing chain, commit to upper backing file (explicitly)
+#     (in this case, the top image will implicitly stay unchanged)
+#  2: Two-layer backing chain, commit to upper backing file (implicitly with -d)
+#     (in this case, the top image will explicitly stay unchanged)
+#  3: Two-layer backing chain, commit to lower backing file
+#     (in this case, the top image will implicitly stay unchanged)
+#
+# 020 already tests committing, so this only tests whether image chains are
+# working properly and that all images above the base are emptied; therefore,
+# no complicated patterns are necessary.  Check near the 2G mark, as qcow2
+# has been buggy at that boundary in the past.
+for i in 0 1 2 3; do
+
+echo
+echo "=== Test pass $reason.$i ==="
+echo
+
+len=$((2100 * 1024 * 1024 + 512)) # larger than 2G, and not cluster aligned
+TEST_IMG="$TEST_IMG.base" _make_test_img $len
+TEST_IMG="$TEST_IMG.itmd" _make_test_img -b "$TEST_IMG.base" -F $IMGFMT $len
+_make_test_img -b "$TEST_IMG.itmd" -F $IMGFMT $len
+# Update the top image to use a feature that is incompatible with fast path
+case $reason in
+    snapshot) $QEMU_IMG snapshot -c snap "$TEST_IMG" ;;
+    bitmap)
+	run_qemu <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "blockdev-add",
+  "arguments": { "driver": "qcow2", "node-name": "drive0",
+     "file": { "driver": "file", "filename": "$TEST_IMG" } } }
+{ "execute": "block-dirty-bitmap-add",
+  "arguments": { "node": "drive0", "name": "bitmap0",
+     "persistent": true } }
+{ "execute": "quit" }
+EOF
+	;;
+esac
+
+$QEMU_IO -c "write -P 1 0x7ffd0000 192k" "$TEST_IMG.base" | _filter_qemu_io
+$QEMU_IO -c "write -P 2 0x7ffe0000 128k" "$TEST_IMG.itmd" | _filter_qemu_io
+$QEMU_IO -c "write -P 3 0x7fff0000 64k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "write -P 4 $(($len - 512)) 512" "$TEST_IMG" | _filter_qemu_io
+
+if [ $i -lt 3 ]; then
+    if [ $i == 0 ]; then
+        # -b "$TEST_IMG.itmd" should be the default (that is, committing to the
+        # first backing file in the chain)
+        $QEMU_IMG commit "$TEST_IMG"
+    elif [ $i == 1 ]; then
+        # explicitly specify the commit target (this should imply -d)
+        $QEMU_IMG commit -b "$TEST_IMG.itmd" "$TEST_IMG"
+    else
+        # do not explicitly specify the commit target, but use -d to leave the
+        # top image unchanged
+        $QEMU_IMG commit -d "$TEST_IMG"
+    fi
+
+    # Bottom should be unchanged
+    $QEMU_IO -c 'read -P 1 0x7ffd0000 192k' "$TEST_IMG.base" | _filter_qemu_io
+    $QEMU_IO -c "read -P 0 $((len - 512)) 512" "$TEST_IMG.base" | _filter_qemu_io
+
+    # Intermediate should contain changes from top
+    $QEMU_IO -c 'read -P 1 0x7ffd0000 64k' "$TEST_IMG.itmd" | _filter_qemu_io
+    $QEMU_IO -c 'read -P 2 0x7ffe0000 64k' "$TEST_IMG.itmd" | _filter_qemu_io
+    $QEMU_IO -c 'read -P 3 0x7fff0000 64k' "$TEST_IMG.itmd" | _filter_qemu_io
+    $QEMU_IO -c "read -P 4 $((len - 512)) 512" "$TEST_IMG.itmd" | _filter_qemu_io
+
+    # And in pass 0, the top image should be empty, whereas in both other passes
+    # it should be unchanged (which is both checked by qemu-img map)
+else
+    $QEMU_IMG commit -b "$TEST_IMG.base" "$TEST_IMG"
+
+    # Bottom should contain all changes
+    $QEMU_IO -c 'read -P 1 0x7ffd0000 64k' "$TEST_IMG.base" | _filter_qemu_io
+    $QEMU_IO -c 'read -P 2 0x7ffe0000 64k' "$TEST_IMG.base" | _filter_qemu_io
+    $QEMU_IO -c 'read -P 3 0x7fff0000 64k' "$TEST_IMG.base" | _filter_qemu_io
+    $QEMU_IO -c "read -P 4 $((len - 512)) 512" "$TEST_IMG.base" | _filter_qemu_io
+
+    # Both top and intermediate should be unchanged
+fi
+
+$QEMU_IMG map "$TEST_IMG.base" | _filter_qemu_img_map
+$QEMU_IMG map "$TEST_IMG.itmd" | _filter_qemu_img_map
+$QEMU_IMG map "$TEST_IMG" | _filter_qemu_img_map
+
+# Check that the reason for slow path is still present, as appropriate
+case $reason in
+    snapshot)
+	$QEMU_IMG snapshot -l "$TEST_IMG" |
+	    sed 's/^\(.\{20\}\).*/\1/; s/ *$//' ;;
+    bitmap)
+	run_qemu <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "blockdev-add",
+  "arguments": { "driver": "qcow2", "node-name": "drive0",
+     "file": { "driver": "file", "filename": "$TEST_IMG" } } }
+{ "execute": "x-debug-block-dirty-bitmap-sha256",
+  "arguments": { "node": "drive0", "name": "bitmap0" } }
+{ "execute": "quit" }
+EOF
+	;;
+esac
+
+done
+done
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0