blockdev-nbd: Boxed argument type for nbd-server-add

Move the arguments of nbd-server-add to a new struct BlockExportNbd and
convert the command to 'boxed': true. This makes it easier to share code
with the storage daemon.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200224143008.13362-11-kwolf@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

blockdev-nbd.c

@@ -148,10 +148,7 @@ void qmp_nbd_server_start(SocketAddressLegacy *addr,
     qapi_free_SocketAddress(addr_flat);
 }
 
-void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
-                        bool has_description, const char *description,
-                        bool has_writable, bool writable,
-                        bool has_bitmap, const char *bitmap, Error **errp)
+void qmp_nbd_server_add(BlockExportNbd *arg, Error **errp)
 {
     BlockDriverState *bs = NULL;
     BlockBackend *on_eject_blk;
@@ -164,28 +161,28 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
         return;
     }
 
-    if (!has_name) {
-        name = device;
+    if (!arg->has_name) {
+        arg->name = arg->device;
     }
 
-    if (strlen(name) > NBD_MAX_STRING_SIZE) {
-        error_setg(errp, "export name '%s' too long", name);
+    if (strlen(arg->name) > NBD_MAX_STRING_SIZE) {
+        error_setg(errp, "export name '%s' too long", arg->name);
         return;
     }
 
-    if (has_description && strlen(description) > NBD_MAX_STRING_SIZE) {
-        error_setg(errp, "description '%s' too long", description);
+    if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) {
+        error_setg(errp, "description '%s' too long", arg->description);
         return;
     }
 
-    if (nbd_export_find(name)) {
-        error_setg(errp, "NBD server already has export named '%s'", name);
+    if (nbd_export_find(arg->name)) {
+        error_setg(errp, "NBD server already has export named '%s'", arg->name);
         return;
     }
 
-    on_eject_blk = blk_by_name(device);
+    on_eject_blk = blk_by_name(arg->device);
 
-    bs = bdrv_lookup_bs(device, device, errp);
+    bs = bdrv_lookup_bs(arg->device, arg->device, errp);
     if (!bs) {
         return;
     }
@@ -199,15 +196,15 @@ void qmp_nbd_server_add(const char *device, bool has_name, const char *name,
         goto out;
     }
 
-    if (!has_writable) {
-        writable = false;
+    if (!arg->has_writable) {
+        arg->writable = false;
     }
     if (bdrv_is_read_only(bs)) {
-        writable = false;
+        arg->writable = false;
     }
 
-    exp = nbd_export_new(bs, 0, len, name, description, bitmap,
-                         !writable, !writable,
+    exp = nbd_export_new(bs, 0, len, arg->name, arg->description, arg->bitmap,
+                         !arg->writable, !arg->writable,
                          NULL, false, on_eject_blk, errp);
     if (!exp) {
         goto out;

monitor/hmp-cmds.c

@@ -2341,6 +2341,7 @@ void hmp_nbd_server_start(Monitor *mon, const QDict *qdict)
     Error *local_err = NULL;
     BlockInfoList *block_list, *info;
     SocketAddress *addr;
+    BlockExportNbd export;
 
     if (writable && !all) {
         error_setg(&local_err, "-w only valid together with -a");
@@ -2373,8 +2374,13 @@ void hmp_nbd_server_start(Monitor *mon, const QDict *qdict)
             continue;
         }
 
-        qmp_nbd_server_add(info->value->device, false, NULL, false, NULL,
-                           true, writable, false, NULL, &local_err);
+        export = (BlockExportNbd) {
+            .device         = info->value->device,
+            .has_writable   = true,
+            .writable       = writable,
+        };
+
+        qmp_nbd_server_add(&export, &local_err);
 
         if (local_err != NULL) {
             qmp_nbd_server_stop(NULL);
@@ -2395,8 +2401,15 @@ 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, !!name, name, false, NULL, true, writable,
-                       false, NULL, &local_err);
+    BlockExportNbd export = {
+        .device         = (char *) device,
+        .has_name       = !!name,
+        .name           = (char *) name,
+        .has_writable   = true,
+        .writable       = writable,
+    };
+
+    qmp_nbd_server_add(&export, &local_err);
     hmp_handle_error(mon, local_err);
 }
 

qapi/block-core.json

@@ -5112,9 +5112,9 @@
             '*tls-authz': 'str'} }
 
 ##
-# @nbd-server-add:
+# @BlockExportNbd:
 #
-# Export a block node to QEMU's embedded NBD server.
+# An NBD block export.
 #
 # @device: The device name or node name of the node to be exported
 #
@@ -5131,14 +5131,24 @@
 #          NBD client can use NBD_OPT_SET_META_CONTEXT with
 #          "qemu:dirty-bitmap:NAME" to inspect the bitmap. (since 4.0)
 #
+# Since: 5.0
+##
+{ 'struct': 'BlockExportNbd',
+  'data': {'device': 'str', '*name': 'str', '*description': 'str',
+           '*writable': 'bool', '*bitmap': 'str' } }
+
+##
+# @nbd-server-add:
+#
+# Export a block node to QEMU's embedded NBD server.
+#
 # 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', '*name': 'str', '*description': 'str',
-           '*writable': 'bool', '*bitmap': 'str' } }
+  'data': 'BlockExportNbd', 'boxed': true }
 
 ##
 # @NbdServerRemoveMode: