[Qemu-devel] [PATCH v3 0/5] nbd export qmp interface

[Qemu-devel] [PATCH v3 0/5] nbd export qmp interface

[Vladimir Sementsov-Ogievskiy]

v3:
hmp patch deleted
02: tweak commit message and comments
    tweak error message
05: use unix socket instead of tcp (more common practice in iotests,
    and we do not need port)
    rebase on new error message in 02

v2:
01: tweak comment
    add Eric's r-b
02: new patch
03: rewritten, to move form 'bool force' flag to 'enum mode' parameter
04: add Eric's r-b
05: improve commit message
    tweak comment
06: rebase on 03 changes
    make PEP8 happy
    some other tweaks
    I've left nbd_port variable hard-set to 10900. I think all such things
    should be fixed together, and it is simple to change in future
    nbd_port = '10900'
    to
    nbd_port = iotests.get_free_port()
    if needed.

[Unfortunately, qmp query-nbd-server is not finished yet, coming soon,
 but may be after my vocation on the next week]

Vladimir Sementsov-Ogievskiy (5):
  qapi: add name parameter to nbd-server-add
  qapi: add nbd-server-remove
  iotest 147: add cases to test new @name parameter of nbd-server-add
  iotests: implement QemuIoInteractive class
  iotest 201: new test for qmp nbd-server-remove

 qapi/block.json               |  50 +++++++++++++-
 include/block/nbd.h           |   1 +
 blockdev-nbd.c                |  38 ++++++++--
 hmp.c                         |   5 +-
 nbd/server.c                  |  20 ++++++
 tests/qemu-iotests/147        |  68 ++++++++++++++----
 tests/qemu-iotests/147.out    |   4 +-
 tests/qemu-iotests/201        | 156 ++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/201.out    |   5 ++
 tests/qemu-iotests/group      |   1 +
 tests/qemu-iotests/iotests.py |  38 ++++++++++
 11 files changed, 362 insertions(+), 24 deletions(-)
 create mode 100644 tests/qemu-iotests/201
 create mode 100644 tests/qemu-iotests/201.out

-- 
2.11.1

[Qemu-devel] [PATCH v3 1/5] qapi: add name parameter to nbd-server-add

[Vladimir Sementsov-Ogievskiy]

Allow user to specify name for new export, to not reuse internal
node name and to not show it to clients.

This also allows creating several exports per device.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 qapi/block.json |  9 +++++++--
 blockdev-nbd.c  | 14 +++++++++-----
 hmp.c           |  5 +++--
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/qapi/block.json b/qapi/block.json
index f093fa3f27..353e3a45bd 100644
--- a/qapi/block.json
+++ b/qapi/block.json
@@ -213,14 +213,19 @@
 #
 # @device: The device name or node name of the node to be exported
 #
+# @name: Export name. If unspecified, the @device parameter is used as the
+#        export name. (Since 2.12)
+#
 # @writable: Whether clients should be able to write to the device via the
 #     NBD connection (default false).
 #
-# Returns: error if the device is already marked for export.
+# Returns: error if the server is not running, or export with the same name
+#          already exists.
 #
 # Since: 1.3.0
 ##
-{ 'command': 'nbd-server-add', 'data': {'device': 'str', '*writable': 'bool'} }
+{ 'command': 'nbd-server-add',
+  'data': {'device': 'str', '*name': 'str', '*writable': 'bool'} }
 
 ##
 # @nbd-server-stop:
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 9e3c22109c..104789e521 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -140,8 +140,8 @@ void qmp_nbd_server_start(SocketAddressLegacy *addr,
     qapi_free_SocketAddress(addr_flat);
 }
 
-void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
-                        Error **errp)
+void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
+                        bool has_writable, bool writable, Error **errp)
 {
     BlockDriverState *bs = NULL;
     BlockBackend *on_eject_blk;
@@ -152,8 +152,12 @@ void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
         return;
     }
 
-    if (nbd_export_find(device)) {
-        error_setg(errp, "NBD server already exporting device '%s'", device);
+    if (!has_name) {
+        name = device;
+    }
+
+    if (nbd_export_find(name)) {
+        error_setg(errp, "NBD server already has export named '%s'", name);
         return;
     }
 
@@ -177,7 +181,7 @@ void qmp_nbd_server_add(const char *device, bool has_writable, bool writable,
         return;
     }
 
-    nbd_export_set_name(exp, device);
+    nbd_export_set_name(exp, name);
 
     /* The list of named exports has a strong reference to this export now and
      * our only way of accessing it is through nbd_export_find(), so we can drop
diff --git a/hmp.c b/hmp.c
index c6bab5373b..37972f8322 100644
--- a/hmp.c
+++ b/hmp.c
@@ -2218,7 +2218,8 @@ void hmp_nbd_server_start(Monitor *mon, const QDict *qdict)
             continue;
         }
 
-        qmp_nbd_server_add(info->value->device, true, writable, &local_err);
+        qmp_nbd_server_add(info->value->device, false, NULL,
+                           true, writable, &local_err);
 
         if (local_err != NULL) {
             qmp_nbd_server_stop(NULL);
@@ -2238,7 +2239,7 @@ void hmp_nbd_server_add(Monitor *mon, const QDict *qdict)
     bool writable = qdict_get_try_bool(qdict, "writable", false);
     Error *local_err = NULL;
 
-    qmp_nbd_server_add(device, true, writable, &local_err);
+    qmp_nbd_server_add(device, false, NULL, true, writable, &local_err);
 
     if (local_err != NULL) {
         hmp_handle_error(mon, &local_err);
-- 
2.11.1

[Qemu-devel] [PATCH v3 2/5] qapi: add nbd-server-remove

[Vladimir Sementsov-Ogievskiy]

Add command for removing an export. It is needed for cases when we
don't want to keep export after the operation on it was completed.
The other example is temporary node, created with blockdev-add.
If we want to delete it we should firstly remove corresponding
NBD export.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 qapi/block.json     | 41 +++++++++++++++++++++++++++++++++++++++++
 include/block/nbd.h |  1 +
 blockdev-nbd.c      | 24 ++++++++++++++++++++++++
 nbd/server.c        | 20 ++++++++++++++++++++
 4 files changed, 86 insertions(+)

diff --git a/qapi/block.json b/qapi/block.json
index 353e3a45bd..c694524002 100644
--- a/qapi/block.json
+++ b/qapi/block.json
@@ -228,6 +228,47 @@
   'data': {'device': 'str', '*name': 'str', '*writable': 'bool'} }
 
 ##
+# @NbdServerRemoveMode:
+#
+# Mode for removing an NBD export.
+#
+# @safe: Remove export if there are no existing connections, fail otherwise.
+#
+# @hard: Drop all connections immediately and remove export.
+#
+# Potential additional modes to be added in the future:
+#
+# hide: Just hide export from new clients, leave existing connections as is.
+#       Remove export after all clients are disconnected.
+#
+# soft: Hide export from new clients, answer with ESHUTDOWN for all further
+#       requests from existing clients.
+#
+# Since: 2.12
+##
+{'enum': 'NbdServerRemoveMode', 'data': ['safe', 'hard']}
+
+##
+# @nbd-server-remove:
+#
+# Remove NBD export by name.
+#
+# @name: Export name.
+#
+# @mode: Mode of command operation. See @NbdServerRemoveMode description.
+#        Default is 'safe'.
+#
+# Returns: error if
+#            - the server is not running
+#            - export is not found
+#            - mode is 'safe' and there are existing connections
+#
+# Since: 2.12
+##
+{ 'command': 'nbd-server-remove',
+  'data': {'name': 'str', '*mode': 'NbdServerRemoveMode'} }
+
+##
 # @nbd-server-stop:
 #
 # Stop QEMU's embedded NBD server, and unregister all devices previously
diff --git a/include/block/nbd.h b/include/block/nbd.h
index 978e443366..ee74ec391a 100644
--- a/include/block/nbd.h
+++ b/include/block/nbd.h
@@ -261,6 +261,7 @@ NBDExport *nbd_export_new(BlockDriverState *bs, off_t dev_offset, off_t size,
                           bool writethrough, BlockBackend *on_eject_blk,
                           Error **errp);
 void nbd_export_close(NBDExport *exp);
+void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp);
 void nbd_export_get(NBDExport *exp);
 void nbd_export_put(NBDExport *exp);
 
diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 104789e521..a9f79c6778 100644
--- a/blockdev-nbd.c
+++ b/blockdev-nbd.c
@@ -189,6 +189,30 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
     nbd_export_put(exp);
 }
 
+void qmp_nbd_server_remove(const char *name,
+                           bool has_mode, NbdServerRemoveMode mode,
+                           Error **errp)
+{
+    NBDExport *exp;
+
+    if (!nbd_server) {
+        error_setg(errp, "NBD server not running");
+        return;
+    }
+
+    exp = nbd_export_find(name);
+    if (exp == NULL) {
+        error_setg(errp, "Export '%s' is not found", name);
+        return;
+    }
+
+    if (!has_mode) {
+        mode = NBD_SERVER_REMOVE_MODE_SAFE;
+    }
+
+    nbd_export_remove(exp, mode, errp);
+}
+
 void qmp_nbd_server_stop(Error **errp)
 {
     nbd_export_close_all();
diff --git a/nbd/server.c b/nbd/server.c
index 6cf2eeb2c1..bf2afd264a 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -1177,6 +1177,26 @@ void nbd_export_close(NBDExport *exp)
     nbd_export_put(exp);
 }
 
+void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp)
+{
+    NBDClient *client;
+    int nb_clients = 0;
+
+    if (mode == NBD_SERVER_REMOVE_MODE_HARD || QTAILQ_EMPTY(&exp->clients)) {
+        nbd_export_close(exp);
+        return;
+    }
+
+    assert(mode == NBD_SERVER_REMOVE_MODE_SAFE);
+
+    QTAILQ_FOREACH(client, &exp->clients, next) {
+        nb_clients++;
+    }
+
+    error_setg(errp, "export '%s' still in use", exp->name);
+    error_append_hint(errp, "Use mode='hard' to force client disconnect\n");
+}
+
 void nbd_export_get(NBDExport *exp)
 {
     assert(exp->refcount > 0);
-- 
2.11.1

[Qemu-devel] [PATCH v3 3/5] iotest 147: add cases to test new @name parameter of nbd-server-add

[Vladimir Sementsov-Ogievskiy]

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 tests/qemu-iotests/147     | 68 +++++++++++++++++++++++++++++++++++++---------
 tests/qemu-iotests/147.out |  4 +--
 2 files changed, 57 insertions(+), 15 deletions(-)

diff --git a/tests/qemu-iotests/147 b/tests/qemu-iotests/147
index 90f40ed245..d2081df84b 100755
--- a/tests/qemu-iotests/147
+++ b/tests/qemu-iotests/147
@@ -38,8 +38,8 @@ def flatten_sock_addr(crumpled_address):
 
 
 class NBDBlockdevAddBase(iotests.QMPTestCase):
-    def blockdev_add_options(self, address, export=None):
-        options = { 'node-name': 'nbd-blockdev',
+    def blockdev_add_options(self, address, export, node_name):
+        options = { 'node-name': node_name,
                     'driver': 'raw',
                     'file': {
                         'driver': 'nbd',
@@ -50,23 +50,28 @@ class NBDBlockdevAddBase(iotests.QMPTestCase):
             options['file']['export'] = export
         return options
 
-    def client_test(self, filename, address, export=None):
-        bao = self.blockdev_add_options(address, export)
+    def client_test(self, filename, address, export=None,
+                    node_name='nbd-blockdev', delete=True):
+        bao = self.blockdev_add_options(address, export, node_name)
         result = self.vm.qmp('blockdev-add', **bao)
         self.assert_qmp(result, 'return', {})
 
+        found = False
         result = self.vm.qmp('query-named-block-nodes')
         for node in result['return']:
-            if node['node-name'] == 'nbd-blockdev':
+            if node['node-name'] == node_name:
+                found = True
                 if isinstance(filename, str):
                     self.assert_qmp(node, 'image/filename', filename)
                 else:
                     self.assert_json_filename_equal(node['image']['filename'],
                                                     filename)
                 break
+        self.assertTrue(found)
 
-        result = self.vm.qmp('blockdev-del', node_name='nbd-blockdev')
-        self.assert_qmp(result, 'return', {})
+        if delete:
+            result = self.vm.qmp('blockdev-del', node_name=node_name)
+            self.assert_qmp(result, 'return', {})
 
 
 class QemuNBD(NBDBlockdevAddBase):
@@ -125,26 +130,63 @@ class BuiltinNBD(NBDBlockdevAddBase):
         except OSError:
             pass
 
-    def _server_up(self, address):
+    def _server_up(self, address, export_name=None, export_name2=None):
         result = self.server.qmp('nbd-server-start', addr=address)
         self.assert_qmp(result, 'return', {})
 
-        result = self.server.qmp('nbd-server-add', device='nbd-export')
+        if export_name is None:
+            result = self.server.qmp('nbd-server-add', device='nbd-export')
+        else:
+            result = self.server.qmp('nbd-server-add', device='nbd-export',
+                                     name=export_name)
         self.assert_qmp(result, 'return', {})
 
+        if export_name2 is not None:
+            result = self.server.qmp('nbd-server-add', device='nbd-export',
+                                     name=export_name2)
+            self.assert_qmp(result, 'return', {})
+
+
     def _server_down(self):
         result = self.server.qmp('nbd-server-stop')
         self.assert_qmp(result, 'return', {})
 
-    def test_inet(self):
+    def do_test_inet(self, export_name=None):
         address = { 'type': 'inet',
                     'data': {
                         'host': 'localhost',
                         'port': str(NBD_PORT)
                     } }
-        self._server_up(address)
-        self.client_test('nbd://localhost:%i/nbd-export' % NBD_PORT,
-                         flatten_sock_addr(address), 'nbd-export')
+        self._server_up(address, export_name)
+        export_name = export_name or 'nbd-export'
+        self.client_test('nbd://localhost:%i/%s' % (NBD_PORT, export_name),
+                         flatten_sock_addr(address), export_name)
+        self._server_down()
+
+    def test_inet_default_export_name(self):
+        self.do_test_inet()
+
+    def test_inet_same_export_name(self):
+        self.do_test_inet('nbd-export')
+
+    def test_inet_different_export_name(self):
+        self.do_test_inet('shadow')
+
+    def test_inet_two_exports(self):
+        address = { 'type': 'inet',
+                    'data': {
+                        'host': 'localhost',
+                        'port': str(NBD_PORT)
+                    } }
+        self._server_up(address, 'exp1', 'exp2')
+        self.client_test('nbd://localhost:%i/%s' % (NBD_PORT, 'exp1'),
+                         flatten_sock_addr(address), 'exp1', 'node1', False)
+        self.client_test('nbd://localhost:%i/%s' % (NBD_PORT, 'exp2'),
+                         flatten_sock_addr(address), 'exp2', 'node2', False)
+        result = self.vm.qmp('blockdev-del', node_name='node1')
+        self.assert_qmp(result, 'return', {})
+        result = self.vm.qmp('blockdev-del', node_name='node2')
+        self.assert_qmp(result, 'return', {})
         self._server_down()
 
     def test_inet6(self):
diff --git a/tests/qemu-iotests/147.out b/tests/qemu-iotests/147.out
index 3f8a935a08..dae404e278 100644
--- a/tests/qemu-iotests/147.out
+++ b/tests/qemu-iotests/147.out
@@ -1,5 +1,5 @@
-......
+.........
 ----------------------------------------------------------------------
-Ran 6 tests
+Ran 9 tests
 
 OK
-- 
2.11.1

[Qemu-devel] [PATCH v3 4/5] iotests: implement QemuIoInteractive class

[Vladimir Sementsov-Ogievskiy]

Implement QemuIoInteractive to test nbd-server-remove command when
there are active connections.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/iotests.py | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 44477e9295..5a10b2d534 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -93,6 +93,44 @@ def qemu_io(*args):
         sys.stderr.write('qemu-io received signal %i: %s\n' % (-exitcode, ' '.join(args)))
     return subp.communicate()[0]
 
+
+class QemuIoInteractive:
+    def __init__(self, *args):
+        self.args = qemu_io_args + list(args)
+        self._p = subprocess.Popen(self.args, stdin=subprocess.PIPE,
+                                   stdout=subprocess.PIPE,
+                                   stderr=subprocess.STDOUT)
+        assert self._p.stdout.read(9) == 'qemu-io> '
+
+    def close(self):
+        self._p.communicate('q\n')
+
+    def _read_output(self):
+        pattern = 'qemu-io> '
+        n = len(pattern)
+        pos = 0
+        s = []
+        while pos != n:
+            c = self._p.stdout.read(1)
+            # check unexpected EOF
+            assert c != ''
+            s.append(c)
+            if c == pattern[pos]:
+                pos += 1
+            else:
+                pos = 0
+
+        return ''.join(s[:-n])
+
+    def cmd(self, cmd):
+        # quit command is in close(), '\n' is added automatically
+        assert '\n' not in cmd
+        cmd = cmd.strip()
+        assert cmd != 'q' and cmd != 'quit'
+        self._p.stdin.write(cmd + '\n')
+        return self._read_output()
+
+
 def qemu_nbd(*args):
     '''Run qemu-nbd in daemon mode and return the parent's exit code'''
     return subprocess.call(qemu_nbd_args + ['--fork'] + list(args))
-- 
2.11.1

[Qemu-devel] [PATCH v3 5/5] iotest 201: new test for qmp nbd-server-remove

[Vladimir Sementsov-Ogievskiy]

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 tests/qemu-iotests/201     | 156 +++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/201.out |   5 ++
 tests/qemu-iotests/group   |   1 +
 3 files changed, 162 insertions(+)
 create mode 100644 tests/qemu-iotests/201
 create mode 100644 tests/qemu-iotests/201.out

diff --git a/tests/qemu-iotests/201 b/tests/qemu-iotests/201
new file mode 100644
index 0000000000..10388920dc
--- /dev/null
+++ b/tests/qemu-iotests/201
@@ -0,0 +1,156 @@
+#!/usr/bin/env python
+#
+# Tests for qmp command nbd-server-remove.
+#
+# Copyright (c) 2017 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 iotests
+import time
+from iotests import qemu_img, qemu_io, filter_qemu_io, QemuIoInteractive
+
+nbd_sock = 'nbd_sock'
+nbd_uri = 'nbd+unix:///exp?socket=' + nbd_sock
+disk = os.path.join(iotests.test_dir, 'disk')
+
+
+class TestNbdServerRemove(iotests.QMPTestCase):
+    def setUp(self):
+        qemu_img('create', '-f', iotests.imgfmt, disk, '1M')
+
+        self.vm = iotests.VM().add_drive(disk)
+        self.vm.launch()
+
+        address = {
+            'type': 'unix',
+            'data': {
+                'path': nbd_sock
+            }
+        }
+
+        result = self.vm.qmp('nbd-server-start', addr=address)
+        self.assert_qmp(result, 'return', {})
+        result = self.vm.qmp('nbd-server-add', device='drive0', name='exp')
+        self.assert_qmp(result, 'return', {})
+
+    def tearDown(self):
+        self.vm.shutdown()
+        os.remove(nbd_sock)
+        os.remove(disk)
+
+    def remove_export(self, name, mode=None):
+        if mode is None:
+            return self.vm.qmp('nbd-server-remove', name=name)
+        else:
+            return self.vm.qmp('nbd-server-remove', name=name, mode=mode)
+
+    def assertExportNotFound(self, name):
+        result = self.vm.qmp('nbd-server-remove', name=name)
+        self.assert_qmp(result, 'error/desc', "Export 'exp' is not found")
+
+    def assertExistingClients(self, result):
+        self.assert_qmp(result, 'error/desc', "export 'exp' still in use")
+
+    def assertReadOk(self, qemu_io_output):
+        self.assertEqual(
+                filter_qemu_io(qemu_io_output).strip(),
+                'read 512/512 bytes at offset 0\n' +
+                '512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)')
+
+    def assertReadFailed(self, qemu_io_output):
+        self.assertEqual(filter_qemu_io(qemu_io_output).strip(),
+                         'read failed: Input/output error')
+
+    def assertConnectFailed(self, qemu_io_output):
+        self.assertEqual(filter_qemu_io(qemu_io_output).strip(),
+                         "can't open device " + nbd_uri +
+                         ": Requested export not available\n"
+                         "server reported: export 'exp' not present")
+
+    def do_test_connect_after_remove(self, mode=None):
+        args = ('-r', '-f', 'raw', '-c', 'read 0 512', nbd_uri)
+        self.assertReadOk(qemu_io(*args))
+
+        result = self.remove_export('exp', mode)
+        self.assert_qmp(result, 'return', {})
+
+        self.assertExportNotFound('exp')
+        self.assertConnectFailed(qemu_io(*args))
+
+    def test_connect_after_remove_default(self):
+        self.do_test_connect_after_remove()
+
+    def test_connect_after_remove_safe(self):
+        self.do_test_connect_after_remove('safe')
+
+    def test_connect_after_remove_force(self):
+        self.do_test_connect_after_remove('hard')
+
+    def do_test_remove_during_connect_safe(self, mode=None):
+        qio = QemuIoInteractive('-r', '-f', 'raw', nbd_uri)
+        self.assertReadOk(qio.cmd('read 0 512'))
+
+        result = self.remove_export('exp', mode)
+        self.assertExistingClients(result)
+
+        self.assertReadOk(qio.cmd('read 0 512'))
+
+        qio.close()
+
+        result = self.remove_export('exp', mode)
+        self.assert_qmp(result, 'return', {})
+
+        self.assertExportNotFound('exp')
+
+    def test_remove_during_connect_default(self):
+        self.do_test_remove_during_connect_safe()
+
+    def test_remove_during_connect_safe(self):
+        self.do_test_remove_during_connect_safe('safe')
+
+    def test_remove_during_connect_hard(self):
+        qio = QemuIoInteractive('-r', '-f', 'raw', nbd_uri)
+        self.assertReadOk(qio.cmd('read 0 512'))
+
+        result = self.remove_export('exp', 'hard')
+        self.assert_qmp(result, 'return', {})
+
+        self.assertReadFailed(qio.cmd('read 0 512'))
+        self.assertExportNotFound('exp')
+
+        qio.close()
+
+    def test_remove_during_connect_safe_hard(self):
+        qio = QemuIoInteractive('-r', '-f', 'raw', nbd_uri)
+        self.assertReadOk(qio.cmd('read 0 512'))
+
+        result = self.remove_export('exp', 'safe')
+        self.assertExistingClients(result)
+
+        self.assertReadOk(qio.cmd('read 0 512'))
+
+        result = self.remove_export('exp', 'hard')
+        self.assert_qmp(result, 'return', {})
+
+        self.assertExportNotFound('exp')
+        self.assertReadFailed(qio.cmd('read 0 512'))
+        qio.close()
+
+
+if __name__ == '__main__':
+    iotests.main()
diff --git a/tests/qemu-iotests/201.out b/tests/qemu-iotests/201.out
new file mode 100644
index 0000000000..2f7d3902f2
--- /dev/null
+++ b/tests/qemu-iotests/201.out
@@ -0,0 +1,5 @@
+.......
+----------------------------------------------------------------------
+Ran 7 tests
+
+OK
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 93d96fb22f..f07d3e3df6 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -197,5 +197,6 @@
 197 rw auto quick
 198 rw auto
 200 rw auto
+201 rw auto quick
 202 rw auto quick
 203 rw auto
-- 
2.11.1

Re: [Qemu-devel] [PATCH v3 2/5] qapi: add nbd-server-remove

[Eric Blake]

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On 01/19/2018 07:57 AM, Vladimir Sementsov-Ogievskiy wrote:
> Add command for removing an export. It is needed for cases when we
> don't want to keep export after the operation on it was completed.
> The other example is temporary node, created with blockdev-add.
> If we want to delete it we should firstly remove corresponding
> NBD export.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---

> +++ b/nbd/server.c
> @@ -1177,6 +1177,26 @@ void nbd_export_close(NBDExport *exp)
>      nbd_export_put(exp);
>  }
>  
> +void nbd_export_remove(NBDExport *exp, NbdServerRemoveMode mode, Error **errp)
> +{
> +    NBDClient *client;
> +    int nb_clients = 0;
> +
> +    if (mode == NBD_SERVER_REMOVE_MODE_HARD || QTAILQ_EMPTY(&exp->clients)) {
> +        nbd_export_close(exp);
> +        return;
> +    }
> +
> +    assert(mode == NBD_SERVER_REMOVE_MODE_SAFE);
> +
> +    QTAILQ_FOREACH(client, &exp->clients, next) {
> +        nb_clients++;
> +    }
> +

Now that the error message is not using nb_clients, we can simplify the
code to quit computing it.

> +    error_setg(errp, "export '%s' still in use", exp->name);
> +    error_append_hint(errp, "Use mode='hard' to force client disconnect\n");
> +}
> +
>  void nbd_export_get(NBDExport *exp)
>  {
>      assert(exp->refcount > 0);
> 

I'll make that change as part of adding it to my NBD queue.
Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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Re: [Qemu-devel] [PATCH v3 5/5] iotest 201: new test for qmp nbd-server-remove

[Eric Blake]

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On 01/19/2018 07:57 AM, Vladimir Sementsov-Ogievskiy wrote:
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  tests/qemu-iotests/201     | 156 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/qemu-iotests/201.out |   5 ++
>  tests/qemu-iotests/group   |   1 +
>  3 files changed, 162 insertions(+)
>  create mode 100644 tests/qemu-iotests/201
>  create mode 100644 tests/qemu-iotests/201.out

Test 201 (and 204) is in Kevin's pull request, I'm renaming this to 205
as part of preparing my NBD queue.
https://lists.gnu.org/archive/html/qemu-devel/2018-01/msg05626.html


> +++ b/tests/qemu-iotests/group
> @@ -197,5 +197,6 @@
>  197 rw auto quick
>  198 rw auto
>  200 rw auto
> +201 rw auto quick
>  202 rw auto quick
>  203 rw auto
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org


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