block: Support multiple reopening with x-blockdev-reopen

[ kwolf: Fixed AioContext locking ]

Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210708114709.206487-5-kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

blockdev.c

@@ -3559,51 +3559,60 @@ fail:
     visit_free(v);
 }
 
-void qmp_x_blockdev_reopen(BlockdevOptions *options, Error **errp)
+void qmp_x_blockdev_reopen(BlockdevOptionsList *reopen_list, Error **errp)
 {
-    BlockDriverState *bs;
+    BlockReopenQueue *queue = NULL;
-    AioContext *ctx;
+    GSList *drained = NULL;
-    QObject *obj;
-    Visitor *v = qobject_output_visitor_new(&obj);
-    BlockReopenQueue *queue;
-    QDict *qdict;
 
-    /* Check for the selected node name */
+    /* Add each one of the BDS that we want to reopen to the queue */
-    if (!options->has_node_name) {
+    for (; reopen_list != NULL; reopen_list = reopen_list->next) {
-        error_setg(errp, "node-name not specified");
+        BlockdevOptions *options = reopen_list->value;
-        goto fail;
+        BlockDriverState *bs;
+        AioContext *ctx;
+        QObject *obj;
+        Visitor *v;
+        QDict *qdict;
+
+        /* Check for the selected node name */
+        if (!options->has_node_name) {
+            error_setg(errp, "node-name not specified");
+            goto fail;
+        }
+
+        bs = bdrv_find_node(options->node_name);
+        if (!bs) {
+            error_setg(errp, "Failed to find node with node-name='%s'",
+                       options->node_name);
+            goto fail;
+        }
+
+        /* Put all options in a QDict and flatten it */
+        v = qobject_output_visitor_new(&obj);
+        visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
+        visit_complete(v, &obj);
+        visit_free(v);
+
+        qdict = qobject_to(QDict, obj);
+
+        qdict_flatten(qdict);
+
+        ctx = bdrv_get_aio_context(bs);
+        aio_context_acquire(ctx);
+
+        bdrv_subtree_drained_begin(bs);
+        queue = bdrv_reopen_queue(queue, bs, qdict, false);
+        drained = g_slist_prepend(drained, bs);
+
+        aio_context_release(ctx);
     }
 
-    bs = bdrv_find_node(options->node_name);
-    if (!bs) {
-        error_setg(errp, "Failed to find node with node-name='%s'",
-                   options->node_name);
-        goto fail;
-    }
-
-    /* Put all options in a QDict and flatten it */
-    visit_type_BlockdevOptions(v, NULL, &options, &error_abort);
-    visit_complete(v, &obj);
-    qdict = qobject_to(QDict, obj);
-
-    qdict_flatten(qdict);
-
     /* Perform the reopen operation */
-    ctx = bdrv_get_aio_context(bs);
-    aio_context_acquire(ctx);
-    bdrv_subtree_drained_begin(bs);
-    aio_context_release(ctx);
-
-    queue = bdrv_reopen_queue(NULL, bs, qdict, false);
     bdrv_reopen_multiple(queue, errp);
-
+    queue = NULL;
-    ctx = bdrv_get_aio_context(bs);
-    aio_context_acquire(ctx);
-    bdrv_subtree_drained_end(bs);
-    aio_context_release(ctx);
 
 fail:
-    visit_free(v);
+    bdrv_reopen_queue_free(queue);
+    g_slist_free_full(drained, (GDestroyNotify) bdrv_subtree_drained_end);
 }
 
 void qmp_blockdev_del(const char *node_name, Error **errp)

qapi/block-core.json

@@ -4221,13 +4221,15 @@
 ##
 # @x-blockdev-reopen:
 #
-# Reopens a block device using the given set of options. Any option
+# Reopens one or more block devices using the given set of options.
-# not specified will be reset to its default value regardless of its
+# Any option not specified will be reset to its default value regardless
-# previous status. If an option cannot be changed or a particular
+# of its previous status. If an option cannot be changed or a particular
 # driver does not support reopening then the command will return an
-# error.
+# error. All devices in the list are reopened in one transaction, so
+# if one of them fails then the whole transaction is cancelled.
 #
-# The top-level @node-name option (from BlockdevOptions) must be
+# The command receives a list of block devices to reopen. For each one
+# of them, the top-level @node-name option (from BlockdevOptions) must be
 # specified and is used to select the block device to be reopened.
 # Other @node-name options must be either omitted or set to the
 # current name of the appropriate node. This command won't change any
@@ -4247,8 +4249,8 @@
 #
 #  4) NULL: the current child (if any) is detached.
 #
-# Options (1) and (2) are supported in all cases, but at the moment
+# Options (1) and (2) are supported in all cases. Option (3) is
-# only @backing allows replacing or detaching an existing child.
+# supported for @file and @backing, and option (4) for @backing only.
 #
 # Unlike with blockdev-add, the @backing option must always be present
 # unless the node being reopened does not have a backing file and its
@@ -4258,7 +4260,7 @@
 # Since: 4.0
 ##
 { 'command': 'x-blockdev-reopen',
-  'data': 'BlockdevOptions', 'boxed': true }
+  'data': { 'options': ['BlockdevOptions'] } }
 
 ##
 # @blockdev-del:

tests/qemu-iotests/155

@@ -261,9 +261,12 @@ class TestBlockdevMirrorReopen(MirrorBaseClass):
             result = self.vm.qmp('blockdev-add', node_name="backing",
                                  driver="null-co")
             self.assert_qmp(result, 'return', {})
-            result = self.vm.qmp('x-blockdev-reopen', node_name="target",
+            result = self.vm.qmp('x-blockdev-reopen', options=[{
-                                 driver=iotests.imgfmt, file="target-file",
+                                     'node-name': "target",
-                                 backing="backing")
+                                     'driver': iotests.imgfmt,
+                                     'file': "target-file",
+                                     'backing': "backing"
+                                 }])
             self.assert_qmp(result, 'return', {})
 
 class TestBlockdevMirrorReopenIothread(TestBlockdevMirrorReopen):

tests/qemu-iotests/165

@@ -137,7 +137,7 @@ class TestPersistentDirtyBitmap(iotests.QMPTestCase):
         assert sha256_1 == self.getSha256()
 
         # Reopen to RW
-        result = self.vm.qmp('x-blockdev-reopen', **{
+        result = self.vm.qmp('x-blockdev-reopen', options=[{
             'node-name': 'node0',
             'driver': iotests.imgfmt,
             'file': {
@@ -145,7 +145,7 @@ class TestPersistentDirtyBitmap(iotests.QMPTestCase):
                 'filename': disk
             },
             'read-only': False
-        })
+        }])
         self.assert_qmp(result, 'return', {})
 
         # Check that bitmap is reopened to RW and we can write to it.

tests/qemu-iotests/245

@@ -85,8 +85,18 @@ class TestBlockdevReopen(iotests.QMPTestCase):
                          "Expected output of %d qemu-io commands, found %d" %
                          (found, self.total_io_cmds))
 
-    # Run x-blockdev-reopen with 'opts' but applying 'newopts'
+    # Run x-blockdev-reopen on a list of block devices
-    # on top of it. The original 'opts' dict is unmodified
+    def reopenMultiple(self, opts, errmsg = None):
+        result = self.vm.qmp('x-blockdev-reopen', conv_keys=False, options=opts)
+        if errmsg:
+            self.assert_qmp(result, 'error/class', 'GenericError')
+            self.assert_qmp(result, 'error/desc', errmsg)
+        else:
+            self.assert_qmp(result, 'return', {})
+
+    # Run x-blockdev-reopen on a single block device (specified by
+    # 'opts') but applying 'newopts' on top of it. The original 'opts'
+    # dict is unmodified
     def reopen(self, opts, newopts = {}, errmsg = None):
         opts = copy.deepcopy(opts)
 
@@ -101,12 +111,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
                 subdict = opts[prefix]
             subdict[key] = value
 
-        result = self.vm.qmp('x-blockdev-reopen', conv_keys = False, **opts)
+        self.reopenMultiple([ opts ], errmsg)
-        if errmsg:
-            self.assert_qmp(result, 'error/class', 'GenericError')
-            self.assert_qmp(result, 'error/desc', errmsg)
-        else:
-            self.assert_qmp(result, 'return', {})
 
 
     # Run query-named-block-nodes and return the specified entry
@@ -142,10 +147,10 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         # We cannot change any of these
         self.reopen(opts, {'node-name': 'not-found'}, "Failed to find node with node-name='not-found'")
         self.reopen(opts, {'node-name': ''}, "Failed to find node with node-name=''")
-        self.reopen(opts, {'node-name': None}, "Invalid parameter type for 'node-name', expected: string")
+        self.reopen(opts, {'node-name': None}, "Invalid parameter type for 'options[0].node-name', expected: string")
         self.reopen(opts, {'driver': 'raw'}, "Cannot change the option 'driver'")
         self.reopen(opts, {'driver': ''}, "Invalid parameter ''")
-        self.reopen(opts, {'driver': None}, "Invalid parameter type for 'driver', expected: string")
+        self.reopen(opts, {'driver': None}, "Invalid parameter type for 'options[0].driver', expected: string")
         self.reopen(opts, {'file': 'not-found'}, "Cannot find device='' nor node-name='not-found'")
         self.reopen(opts, {'file': ''}, "Cannot find device='' nor node-name=''")
         self.reopen(opts, {'file': None}, "Invalid parameter type for 'file', expected: BlockdevRef")
@@ -154,7 +159,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.reopen(opts, {'file.filename': hd_path[1]}, "Cannot change the option 'filename'")
         self.reopen(opts, {'file.aio': 'native'}, "Cannot change the option 'aio'")
         self.reopen(opts, {'file.locking': 'off'}, "Cannot change the option 'locking'")
-        self.reopen(opts, {'file.filename': None}, "Invalid parameter type for 'file.filename', expected: string")
+        self.reopen(opts, {'file.filename': None}, "Invalid parameter type for 'options[0].file.filename', expected: string")
 
         # node-name is optional in BlockdevOptions, but x-blockdev-reopen needs it
         del opts['node-name']

tests/qemu-iotests/248

@@ -63,7 +63,7 @@ vm.get_qmp_events()
 
 del blockdev_opts['file']['size']
 vm.qmp_log('x-blockdev-reopen', filters=[filter_qmp_testfiles],
-           **blockdev_opts)
+           options = [ blockdev_opts ])
 
 vm.qmp_log('block-job-resume', device='drive0')
 vm.event_wait('JOB_STATUS_CHANGE', timeout=1.0,

tests/qemu-iotests/248.out

@@ -2,7 +2,7 @@
 {"return": {}}
 {"execute": "blockdev-mirror", "arguments": {"device": "drive0", "on-target-error": "enospc", "sync": "full", "target": "target"}}
 {"return": {}}
-{"execute": "x-blockdev-reopen", "arguments": {"driver": "qcow2", "file": {"driver": "raw", "file": {"driver": "file", "filename": "TEST_DIR/PID-target"}}, "node-name": "target"}}
+{"execute": "x-blockdev-reopen", "arguments": {"options": [{"driver": "qcow2", "file": {"driver": "raw", "file": {"driver": "file", "filename": "TEST_DIR/PID-target"}}, "node-name": "target"}]}}
 {"return": {}}
 {"execute": "block-job-resume", "arguments": {"device": "drive0"}}
 {"return": {}}

tests/qemu-iotests/296

@@ -120,8 +120,7 @@ class EncryptionSetupTestCase(iotests.QMPTestCase):
 
         command = 'x-blockdev-reopen' if reOpen else 'blockdev-add'
 
-        result = vm.qmp(command, **
+        opts = {
-            {
                 'driver': iotests.imgfmt,
                 'node-name': id,
                 'read-only': readOnly,
@@ -131,7 +130,11 @@ class EncryptionSetupTestCase(iotests.QMPTestCase):
                     'filename': test_img,
                 }
             }
-        )
+
+        if reOpen:
+            result = vm.qmp(command, options=[opts])
+        else:
+            result = vm.qmp(command, **opts)
         self.assert_qmp(result, 'return', {})
 
 

tests/qemu-iotests/298

@@ -98,7 +98,7 @@ class TestPreallocateFilter(TestPreallocateBase):
         self.check_big()
 
     def test_reopen_opts(self):
-        result = self.vm.qmp('x-blockdev-reopen', **{
+        result = self.vm.qmp('x-blockdev-reopen', options=[{
             'node-name': 'disk',
             'driver': iotests.imgfmt,
             'file': {
@@ -112,7 +112,7 @@ class TestPreallocateFilter(TestPreallocateBase):
                     'filename': disk
                 }
             }
-        })
+        }])
         self.assert_qmp(result, 'return', {})
 
         self.vm.hmp_qemu_io('drive0', 'write 0 1M')

tests/qemu-iotests/tests/remove-bitmap-from-backing

@@ -41,13 +41,15 @@ log('Trying to remove persistent bitmap from r-o base node, should fail:')
 vm.qmp_log('block-dirty-bitmap-remove', node='base', name='bitmap0')
 
 new_base_opts = {
-    'node-name': 'base',
+    'options': [{
-    'driver': 'qcow2',
+        'node-name': 'base',
-    'file': {
+        'driver': 'qcow2',
-        'driver': 'file',
+        'file': {
-        'filename':  base
+            'driver': 'file',
-    },
+            'filename':  base
-    'read-only': False
+        },
+        'read-only': False
+    }]
 }
 
 # Don't want to bother with filtering qmp_log for reopen command
@@ -58,7 +60,7 @@ if result != {'return': {}}:
 log('Remove persistent bitmap from base node reopened to RW:')
 vm.qmp_log('block-dirty-bitmap-remove', node='base', name='bitmap0')
 
-new_base_opts['read-only'] = True
+new_base_opts['options'][0]['read-only'] = True
 result = vm.qmp('x-blockdev-reopen', **new_base_opts)
 if result != {'return': {}}:
     log('Failed to reopen: ' + str(result))