[libvirt] [PATCHv1 2/5] storage: use virBuffer for generating qemu options string

[Ján Tomko]

---
 src/storage/storage_backend.c |   36 ++++++++++++++++++------------------
 1 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index 9f598fc..a7e9493 100644
--- a/src/storage/storage_backend.c
+++ b/src/storage/storage_backend.c
@@ -669,6 +669,8 @@ virStorageBackendCreateQemuImg(virConnectPtr conn,
     bool do_encryption = (vol->target.encryption != NULL);
     unsigned long long int size_arg;
     bool preallocate = false;
+    char *options;
+    virBuffer buf = VIR_BUFFER_INITIALIZER;
 
     virCheckFlags(VIR_STORAGE_VOL_CREATE_PREALLOC_METADATA, -1);
 
@@ -821,25 +823,23 @@ virStorageBackendCreateQemuImg(virConnectPtr conn,
     }
 
     if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS) {
-        if (inputvol) {
-            if (do_encryption || preallocate) {
-                virCommandAddArg(cmd, "-o");
-                virCommandAddArgFormat(cmd, "%s%s%s", do_encryption ? "encryption=on" : "",
-                                       (do_encryption && preallocate) ? "," : "",
-                                       preallocate ? "preallocation=metadata" : "");
-            }
-        } else if (vol->backingStore.path) {
-            virCommandAddArg(cmd, "-o");
-            virCommandAddArgFormat(cmd, "backing_fmt=%s%s", backingType,
-                                   do_encryption ? ",encryption=on" : "");
-        } else {
-            if (do_encryption || preallocate) {
-                virCommandAddArg(cmd, "-o");
-                virCommandAddArgFormat(cmd, "%s%s%s", do_encryption ? "encryption=on" : "",
-                                       (do_encryption && preallocate) ? "," : "",
-                                       preallocate ? "preallocation=metadata" : "");
-            }
+        if (do_encryption)
+            virBufferAddLit(&buf, ",encryption=on");
+
+        if (!inputvol && vol->backingStore.path)
+            virBufferAsprintf(&buf, ",backing_fmt=%s", backingType);
+        else if (preallocate)
+            virBufferAddLit(&buf, ",preallocation=metadata");
+
+        if (virBufferError(&buf) > 0) {
+            virReportOOMError();
+            goto cleanup;
         }
+
+        if ((options = virBufferContentAndReset(&buf)))
+            virCommandAddArgList(cmd, "-o", &(options[1]), NULL);
+
+        VIR_FREE(options);
     } else {
         if (!inputvol && vol->backingStore.path) {
             if (imgformat == QEMU_IMG_BACKING_FORMAT_FLAG)
-- 
1.7.8.6