qemu: command: Add support for multi-host gluster disks

To allow using failover with gluster it's necessary to specify multiple
volume hosts. Add support for starting qemu with such configurations.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>

docs/formatdomain.html.in

@@ -2280,7 +2280,7 @@
               <tr>
                 <td> gluster </td>
                 <td> a server running glusterd daemon </td>
-                <td> only one </td>
+                <td> one or more (<span class="since">Since 2.1.0</span>), just one prior to that </td>
                 <td> 24007 </td>
               </tr>
             </table>

src/qemu/qemu_command.c

@@ -689,6 +689,100 @@ qemuBuildRBDSecinfoURI(virBufferPtr buf,
 
 
 #define QEMU_DEFAULT_NBD_PORT "10809"
+#define QEMU_DEFAULT_GLUSTER_PORT "24007"
+
+/* builds the hosts array */
+static virJSONValuePtr
+qemuBuildGlusterDriveJSONHosts(virStorageSourcePtr src)
+{
+    virJSONValuePtr servers = NULL;
+    virJSONValuePtr server = NULL;
+    virJSONValuePtr ret = NULL;
+    virStorageNetHostDefPtr host;
+    const char *transport;
+    const char *portstr;
+    size_t i;
+
+    if (!(servers = virJSONValueNewArray()))
+        goto cleanup;
+
+    for (i = 0; i < src->nhosts; i++) {
+        host = src->hosts + i;
+        transport = virStorageNetHostTransportTypeToString(host->transport);
+        portstr = host->port;
+
+        if (virJSONValueObjectCreate(&server, "s:type", transport, NULL) < 0)
+            goto cleanup;
+
+        if (!portstr)
+            portstr = QEMU_DEFAULT_GLUSTER_PORT;
+
+        switch ((virStorageNetHostTransport) host->transport) {
+        case VIR_STORAGE_NET_HOST_TRANS_TCP:
+            if (virJSONValueObjectAdd(server,
+                                      "s:host", host->name,
+                                      "s:port", portstr,
+                                      NULL) < 0)
+                goto cleanup;
+            break;
+
+        case VIR_STORAGE_NET_HOST_TRANS_UNIX:
+            if (virJSONValueObjectAdd(server,
+                                      "s:socket", host->socket,
+                                      NULL) < 0)
+                goto cleanup;
+            break;
+
+        case VIR_STORAGE_NET_HOST_TRANS_RDMA:
+        case VIR_STORAGE_NET_HOST_TRANS_LAST:
+            virReportError(VIR_ERR_INTERNAL_ERROR,
+                           _("transport protocol '%s' is not yet supported"),
+                           transport);
+            goto cleanup;
+        }
+
+        if (virJSONValueArrayAppend(servers, server) < 0)
+            goto cleanup;
+
+        server = NULL;
+    }
+
+    ret = servers;
+    servers = NULL;
+
+ cleanup:
+    virJSONValueFree(servers);
+    virJSONValueFree(server);
+
+    return ret;
+}
+
+
+static virJSONValuePtr
+qemuBuildGlusterDriveJSON(virStorageSourcePtr src)
+{
+    const char *protocol = virStorageNetProtocolTypeToString(src->protocol);
+    virJSONValuePtr servers = NULL;
+    virJSONValuePtr ret = NULL;
+
+    if (!(servers = qemuBuildGlusterDriveJSONHosts(src)))
+        return NULL;
+
+     /* { driver:"gluster",
+      *   volume:"testvol",
+      *   path:"/a.img",
+      *   server :[{type:"tcp", host:"1.2.3.4", port:24007},
+      *            {type:"unix", socket:"/tmp/glusterd.socket"}, ...]}
+      */
+    if (virJSONValueObjectCreate(&ret,
+                                 "s:driver", protocol,
+                                 "s:volume", src->volume,
+                                 "s:path", src->path,
+                                 "a:server", servers, NULL) < 0)
+          virJSONValueFree(servers);
+
+    return ret;
+}
 
 
 static char *
@@ -932,7 +1026,14 @@ qemuGetDriveSourceProps(virStorageSourcePtr src,
     case VIR_STORAGE_TYPE_VOLUME:
     case VIR_STORAGE_TYPE_NONE:
     case VIR_STORAGE_TYPE_LAST:
+        break;
+
     case VIR_STORAGE_TYPE_NETWORK:
+        if (src->protocol == VIR_STORAGE_NET_PROTOCOL_GLUSTER &&
+            src->nhosts > 1) {
+            if (!(fileprops = qemuBuildGlusterDriveJSON(src)))
+                return -1;
+        }
         break;
     }
 

tests/qemuxml2argvdata/qemuxml2argv-disk-drive-network-gluster.args

@@ -24,4 +24,11 @@ id=virtio-disk0 \
 -drive 'file=gluster+unix:///Volume2/Image?socket=/path/to/sock,format=raw,\
 if=none,id=drive-virtio-disk1' \
 -device virtio-blk-pci,bus=pci.0,addr=0x4,drive=drive-virtio-disk1,\
-id=virtio-disk1
+id=virtio-disk1 \
+-drive file.driver=gluster,file.volume=Volume3,file.path=/Image.qcow2,\
+file.server.0.type=tcp,file.server.0.host=example.org,file.server.0.port=6000,\
+file.server.1.type=tcp,file.server.1.host=example.org,file.server.1.port=24007,\
+file.server.2.type=unix,file.server.2.socket=/path/to/sock,format=qcow2,\
+if=none,id=drive-virtio-disk2 \
+-device virtio-blk-pci,bus=pci.0,addr=0x5,drive=drive-virtio-disk2,\
+id=virtio-disk2

tests/qemuxml2argvdata/qemuxml2argv-disk-drive-network-gluster.xml

@@ -28,6 +28,15 @@
       </source>
       <target dev='vdb' bus='virtio'/>
     </disk>
+    <disk type='network' device='disk'>
+      <driver name='qemu' type='qcow2'/>
+      <source protocol='gluster' name='Volume3/Image.qcow2'>
+        <host name='example.org' port='6000'/>
+        <host name='example.org'/>
+        <host transport='unix' socket='/path/to/sock'/>
+      </source>
+      <target dev='vdc' bus='virtio'/>
+    </disk>
     <controller type='usb' index='0'/>
     <controller type='pci' index='0' model='pci-root'/>
     <input type='mouse' bus='ps2'/>

tests/qemuxml2xmloutdata/qemuxml2xmlout-disk-drive-network-gluster.xml

@@ -30,6 +30,16 @@
       <target dev='vdb' bus='virtio'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/>
     </disk>
+    <disk type='network' device='disk'>
+      <driver name='qemu' type='qcow2'/>
+      <source protocol='gluster' name='Volume3/Image.qcow2'>
+        <host name='example.org' port='6000'/>
+        <host name='example.org'/>
+        <host transport='unix' socket='/path/to/sock'/>
+      </source>
+      <target dev='vdc' bus='virtio'/>
+      <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/>
+    </disk>
     <controller type='usb' index='0'>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x2'/>
     </controller>