qapi: add name parameter to nbd-server-add

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>
Message-Id: <20180119135719.24745-2-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>

diff --git a/blockdev-nbd.c b/blockdev-nbd.c
index 9e3c22109c6e6b4c905a3e5706f7a4378754d3b1..104789e521c167ad3ce49e308dadec121ecd6fe6 100644 (file)
--- 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 056bf70cf1e2dc13aa6ccf00350454b38417c284..5bcfc36de107e3307b6562a0fdea1d6064700e44 100644 (file)
--- a/hmp.c
+++ b/hmp.c
@@ -2203,7 +2203,8 @@ 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);
@@ -2223,7 +2224,7 @@ 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);

diff --git a/qapi/block.json b/qapi/block.json
index f093fa3f27641625fbb9151e59863cd316f114c4..353e3a45bdf8e340a2983d8e7a3fad4331718321 100644 (file)
--- 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: