qemu-iotests: add 058 internal snapshot export with qemu-nbd case

This case can't run when IMGPROTO=nbd, since it needs to create some
internal snapshot which would fail for EOF write request, even when
TEST_IMG is exported with "-f raw" in common.rc, so set _supported_proto
to file.

_require_command() is changed to tip what util is missing, instead
of printing a blank.

Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

tests/qemu-iotests/058

@@ -0,0 +1,121 @@
+#!/bin/bash
+#
+# Test export internal snapshot by qemu-nbd.
+#
+# Copyright (C) 2013 IBM, Inc.
+#
+# Based on 029.
+#
+# 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=xiawenc@linux.vnet.ibm.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1	# failure is the default!
+
+nbd_unix_socket=$TEST_DIR/test_qemu_nbd_socket
+nbd_snapshot_img="nbd:unix:$nbd_unix_socket"
+
+_cleanup_nbd()
+{
+    if [ -n "$NBD_SNAPSHOT_PID" ]; then
+        kill "$NBD_SNAPSHOT_PID"
+    fi
+    rm -f "$nbd_unix_socket"
+}
+
+_wait_for_nbd()
+{
+    for ((i = 0; i < 300; i++))
+    do
+        if [ -r "$nbd_unix_socket" ]; then
+            return
+        fi
+        sleep 0.1
+    done
+    echo "Failed in check of unix socket created by qemu-nbd"
+    exit 1
+}
+
+_export_nbd_snapshot()
+{
+    _cleanup_nbd
+    $QEMU_NBD -v -t -k "$nbd_unix_socket" "$TEST_IMG" -l $1 &
+    NBD_SNAPSHOT_PID=$!
+    _wait_for_nbd
+}
+
+_export_nbd_snapshot1()
+{
+    _cleanup_nbd
+    $QEMU_NBD -v -t -k "$nbd_unix_socket" "$TEST_IMG" -l snapshot.name=$1 &
+    NBD_SNAPSHOT_PID=$!
+    _wait_for_nbd
+}
+
+_cleanup()
+{
+    _cleanup_nbd
+    _cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+. ./common.pattern
+
+_supported_fmt qcow2
+_supported_proto file
+_require_command QEMU_NBD
+
+echo
+echo "== preparing image =="
+_make_test_img 64M
+$QEMU_IO -c 'write -P 0xa 0x1000 0x1000' "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c 'write -P 0xb 0x2000 0x1000' "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG snapshot -c sn1 "$TEST_IMG"
+$QEMU_IO -c 'write -P 0xc 0x1000 0x1000' "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c 'write -P 0xd 0x2000 0x1000' "$TEST_IMG" | _filter_qemu_io
+_check_test_img
+
+echo
+echo "== verifying the image file with patterns =="
+$QEMU_IO -c 'read -P 0xc 0x1000 0x1000' "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c 'read -P 0xd 0x2000 0x1000' "$TEST_IMG" | _filter_qemu_io
+
+_export_nbd_snapshot sn1
+
+echo
+echo "== verifying the exported snapshot with patterns, method 1 =="
+$QEMU_IO -c 'read -P 0xa 0x1000 0x1000' "$nbd_snapshot_img" | _filter_qemu_io
+$QEMU_IO -c 'read -P 0xb 0x2000 0x1000' "$nbd_snapshot_img" | _filter_qemu_io
+
+_export_nbd_snapshot1 sn1
+
+echo
+echo "== verifying the exported snapshot with patterns, method 2 =="
+$QEMU_IO -c 'read -P 0xa 0x1000 0x1000' "$nbd_snapshot_img" | _filter_qemu_io
+$QEMU_IO -c 'read -P 0xb 0x2000 0x1000' "$nbd_snapshot_img" | _filter_qemu_io
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0

tests/qemu-iotests/058.out

@@ -0,0 +1,32 @@
+QA output created by 058
+
+== preparing image ==
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
+wrote 4096/4096 bytes at offset 4096
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 4096/4096 bytes at offset 8192
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 4096/4096 bytes at offset 4096
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 4096/4096 bytes at offset 8192
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+No errors were found on the image.
+
+== verifying the image file with patterns ==
+read 4096/4096 bytes at offset 4096
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 4096/4096 bytes at offset 8192
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying the exported snapshot with patterns, method 1 ==
+read 4096/4096 bytes at offset 4096
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 4096/4096 bytes at offset 8192
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+== verifying the exported snapshot with patterns, method 2 ==
+read 4096/4096 bytes at offset 4096
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 4096/4096 bytes at offset 8192
+4 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+*** done

tests/qemu-iotests/check

@@ -161,6 +161,7 @@ cat <<EOF
 QEMU          -- $QEMU
 QEMU_IMG      -- $QEMU_IMG
 QEMU_IO       -- $QEMU_IO
+QEMU_NBD      -- $QEMU_NBD
 IMGFMT        -- $FULL_IMGFMT_DETAILS
 IMGPROTO      -- $FULL_IMGPROTO_DETAILS
 PLATFORM      -- $FULL_HOST_DETAILS

tests/qemu-iotests/common.rc

@@ -410,7 +410,8 @@ _default_cache_mode()
 #
 _require_command()
 {
-    [ -x "$1" ] || _notrun "$1 utility required, skipped this test"
+    eval c=\$$1
+    [ -x "$c" ] || _notrun "$1 utility required, skipped this test"
 }
 
 _full_imgfmt_details()

tests/qemu-iotests/group

@@ -64,6 +64,7 @@
 055 rw auto
 056 rw auto backing
 057 rw auto
+058 rw auto
 059 rw auto
 060 rw auto
 061 rw auto