[v2] iotests: Test NBD client reconnect

diff --git a/tests/qemu-iotests/277 b/tests/qemu-iotests/277
new file mode 100755
index 0000000..2fca565
--- /dev/null
+++ b/tests/qemu-iotests/277
@@ -0,0 +1,94 @@ 
+#!/usr/bin/env python
+#
+# Test nbd client reconnect
+#
+# Copyright (c) 2019 Virtuozzo International GmbH
+#
+# 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/>.
+#
+
+import os
+import sys
+import subprocess
+import iotests
+from iotests import file_path, log
+
+
+def start_server_NBD(nbd_sock, conf_file):
+    srv = subprocess.Popen(["nbd-fault-injector.py", "--classic-negotiation",
+                           nbd_sock, conf_file], stdout=subprocess.PIPE,
+                           stderr=subprocess.STDOUT, universal_newlines=True)
+    line = srv.stdout.readline()
+    if "Listening on " in line:
+        log('NBD server: started')
+    else:
+        log('NBD server: ' + line.rstrip())
+
+    return srv
+
+
+def check_server_NBD(srv):
+    exitcode = srv.wait(timeout=10)
+
+    if exitcode < 0:
+        sys.stderr.write('NBD server: ERROR %i\n' % (-exitcode))
+        log(srv.communicate()[0])
+    else:
+        line = srv.stdout.readline()
+        log('NBD server: ' + line.rstrip())
+
+    os.remove(nbd_sock)
+    os.remove(conf_file)
+
+
+def make_conf_file(conf_file, event):
+    if os.path.exists(conf_file):
+        os.remove(conf_file)
+
+    with open(conf_file, "w+") as conff:
+        conff.write("[inject-error]\nevent={}\nwhen=after".format(event))
+
+
+nbd_sock = file_path('nbd-sock')
+nbd_uri = 'nbd+unix:///?socket=' + nbd_sock
+if os.path.exists(nbd_sock):
+    os.remove(nbd_sock)
+
+conf_file = os.path.join(iotests.test_dir, "nbd-fault-injector.conf")
+make_conf_file(conf_file, "data")
+srv = start_server_NBD(nbd_sock, conf_file)
+
+log('NBD client: QEMU-IO write')
+args = iotests.qemu_io_args + ['-f', 'raw', '-c', 'write -P 0x7 0 3M', nbd_uri]
+clt = subprocess.Popen(args, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
+                       universal_newlines=True)
+
+check_server_NBD(srv)
+
+line = clt.stdout.readline()
+log('NBD client: ' + line.rstrip())
+
+make_conf_file(conf_file, "reply")
+srv = start_server_NBD(nbd_sock, conf_file)
+
+exitcode = clt.wait(timeout=10)
+if exitcode < 0:
+    sys.stderr.write('qemu-io received signal %i: %s\n' %
+                     (-exitcode, ' '.join(args)))
+    log(clt.communicate()[0])
+else:
+    line = clt.stdout.readline()
+    log('NBD client: ' + line.rstrip())
+
+check_server_NBD(srv)
diff --git a/tests/qemu-iotests/277.out b/tests/qemu-iotests/277.out
new file mode 100644
index 0000000..f899b6c
--- /dev/null
+++ b/tests/qemu-iotests/277.out
@@ -0,0 +1,7 @@ 
+NBD server: started
+NBD client: QEMU-IO write
+NBD server: Closing connection on rule match inject-error
+NBD client: Connection closed
+NBD server: started
+NBD client: wrote 3145728/3145728 bytes at offset 0
+NBD server: Closing connection on rule match inject-error
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index af322af..22ef1b8 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -282,3 +282,4 @@ 
 267 rw auto quick snapshot
 268 rw auto quick
 270 rw backing quick
+277 rw
diff --git a/tests/qemu-iotests/nbd-fault-injector.py b/tests/qemu-iotests/nbd-fault-injector.py
index 6b2d659..7e2dab6 100755
--- a/tests/qemu-iotests/nbd-fault-injector.py
+++ b/tests/qemu-iotests/nbd-fault-injector.py
@@ -115,7 +115,8 @@  class FaultInjectionSocket(object):
             if rule.match(event, io):
                 if rule.when == 0 or bufsize is None:
                     print('Closing connection on rule match %s' % rule.name)
-                    self.sock.flush()
+                    self.sock.close()
+                    sys.stdout.flush()
                     sys.exit(0)
                 if rule.when != -1:
                     return rule.when