storage: dir: .resizeVol callback for ploop volume

Changes the size of given ploop volume via ploop resize tool.
Signed-off-by: NOlga Krishtal <okrishtal@virtuozzo.com>

src/storage/storage_backend.c

@@ -850,6 +850,31 @@ virStorageBackendCreatePloop(virConnectPtr conn ATTRIBUTE_UNUSED,
     return ret;
 }
 
+int
+virStoragePloopResize(virStorageVolDefPtr vol,
+                      unsigned long long capacity)
+{
+    int ret = -1;
+    virCommandPtr cmd = NULL;
+    char *resize_tool = NULL;
+
+    resize_tool = virFindFileInPath("ploop");
+    if (!resize_tool) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("unable to find ploop, please install ploop tools"));
+        return -1;
+    }
+    cmd = virCommandNewArgList(resize_tool, "resize", "-s", NULL);
+    virCommandAddArgFormat(cmd, "%lluM", VIR_DIV_UP(capacity, (1024 * 1024)));
+
+    virCommandAddArgFormat(cmd, "%s/DiskDescriptor.xml", vol->target.path);
+
+    ret = virCommandRun(cmd, NULL);
+    virCommandFree(cmd);
+    VIR_FREE(resize_tool);
+    return ret;
+}
+
 enum {
     QEMU_IMG_BACKING_FORMAT_NONE = 0,
     QEMU_IMG_BACKING_FORMAT_FLAG,

src/storage/storage_backend.h

@@ -115,6 +115,8 @@ int virStorageBackendCreatePloop(virConnectPtr conn,
                                  virStorageVolDefPtr inputvol,
                                  unsigned int flags);
 
+int virStoragePloopResize(virStorageVolDefPtr vol,
+                          unsigned long long capacity);
 
 virStorageBackendBuildVolFrom
 virStorageBackendGetBuildVolFromFunction(virStorageVolDefPtr vol,

src/storage/storage_backend_fs.c

@@ -1379,6 +1379,8 @@ virStorageBackendFileSystemVolResize(virConnectPtr conn ATTRIBUTE_UNUSED,
     if (vol->target.format == VIR_STORAGE_FILE_RAW) {
         return virStorageFileResize(vol->target.path, capacity,
                                     vol->target.allocation, pre_allocate);
+    } else if (vol->target.format == VIR_STORAGE_FILE_PLOOP) {
+        return virStoragePloopResize(vol, capacity);
     } else {
         if (pre_allocate) {
             virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s",