[libvirt] [PATCHv1 1/5] storage: refactor qemu-img command line generation

[Ján Tomko]

This makes adding new options easier. The only change in command line is
movement of -o or -F options to the end for creating images with backing
stores.
---
 src/storage/storage_backend.c |   77 ++++++++++++++++------------------------
 1 files changed, 31 insertions(+), 46 deletions(-)

diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c
index df79b28..9f598fc 100644
--- a/src/storage/storage_backend.c
+++ b/src/storage/storage_backend.c
@@ -810,61 +810,46 @@ virStorageBackendCreateQemuImg(virConnectPtr conn,
     if (inputvol) {
         virCommandAddArgList(cmd, "convert", "-f", inputType, "-O", type,
                              inputPath, vol->target.path, NULL);
-
-        if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS &&
-            (do_encryption || preallocate)) {
-            virCommandAddArg(cmd, "-o");
-            virCommandAddArgFormat(cmd, "%s%s%s", do_encryption ? "encryption=on" : "",
-                                   (do_encryption && preallocate) ? "," : "",
-                                   preallocate ? "preallocation=metadata" : "");
-        } else if (do_encryption) {
-            virCommandAddArg(cmd, "-e");
-        }
     } else if (vol->backingStore.path) {
+        virCommandAddArgList(cmd, "create", "-f", type, "-b",
+                             vol->backingStore.path, vol->target.path, NULL);
+        virCommandAddArgFormat(cmd, "%lluK", size_arg);
+    } else {
         virCommandAddArgList(cmd, "create", "-f", type,
-                             "-b", vol->backingStore.path, NULL);
-
-        switch (imgformat) {
-        case QEMU_IMG_BACKING_FORMAT_FLAG:
-            virCommandAddArgList(cmd, "-F", backingType, vol->target.path,
-                                 NULL);
-            virCommandAddArgFormat(cmd, "%lluK", size_arg);
-
-            if (do_encryption)
-                virCommandAddArg(cmd, "-e");
-            break;
+                             vol->target.path, NULL);
+        virCommandAddArgFormat(cmd, "%lluK", size_arg);
+    }
 
-        case QEMU_IMG_BACKING_FORMAT_OPTIONS:
+    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" : "");
-            virCommandAddArg(cmd, vol->target.path);
-            virCommandAddArgFormat(cmd, "%lluK", size_arg);
-            break;
-
-        default:
-            VIR_INFO("Unable to set backing store format for %s with %s",
-                     vol->target.path, create_tool);
-
-            virCommandAddArg(cmd, vol->target.path);
-            virCommandAddArgFormat(cmd, "%lluK", size_arg);
-            if (do_encryption)
-                virCommandAddArg(cmd, "-e");
+        } else {
+            if (do_encryption || preallocate) {
+                virCommandAddArg(cmd, "-o");
+                virCommandAddArgFormat(cmd, "%s%s%s", do_encryption ? "encryption=on" : "",
+                                       (do_encryption && preallocate) ? "," : "",
+                                       preallocate ? "preallocation=metadata" : "");
+            }
         }
     } else {
-        virCommandAddArgList(cmd, "create", "-f", type,
-                             vol->target.path, NULL);
-        virCommandAddArgFormat(cmd, "%lluK", size_arg);
-
-        if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS &&
-            (do_encryption || preallocate)) {
-            virCommandAddArg(cmd, "-o");
-            virCommandAddArgFormat(cmd, "%s%s%s", do_encryption ? "encryption=on" : "",
-                                   (do_encryption && preallocate) ? "," : "",
-                                   preallocate ? "preallocation=metadata" : "");
-        } else if (do_encryption) {
-            virCommandAddArg(cmd, "-e");
+        if (!inputvol && vol->backingStore.path) {
+            if (imgformat == QEMU_IMG_BACKING_FORMAT_FLAG)
+                virCommandAddArgList(cmd, "-F", backingType, NULL);
+            else
+                VIR_INFO("Unable to set backing store format for %s with %s",
+                         vol->target.path, create_tool);
         }
+        if (do_encryption)
+            virCommandAddArg(cmd, "-e");
     }
 
     ret = virStorageBackendCreateExecCommand(pool, vol, cmd);
-- 
1.7.8.6