qemu: block: Introduce qemuBlockStorageSourceGetSliceNodename

The helper retrieves the nodename of the slice layer if it's present.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/qemu/qemu_block.c

@@ -101,6 +101,22 @@ qemuBlockStorageSourceGetEffectiveNodename(virStorageSource *src)
 }
 
 
+/**
+ * qemuBlockStorageSourceGetSliceNodename:
+ *
+ * Gets the nodename corresponding to the storage slice layer. Returns NULL
+ * when there is no explicit storage slice layer.
+ */
+const char *
+qemuBlockStorageSourceGetSliceNodename(virStorageSource *src)
+{
+    if (!src->sliceStorage)
+        return NULL;
+
+    return src->sliceStorage->nodename;
+}
+
+
 /**
  * qemuBlockStorageSourceGetEffectiveStorageNodename:
  * @src: virStorageSource to get the effective nodename of
@@ -111,9 +127,10 @@ qemuBlockStorageSourceGetEffectiveNodename(virStorageSource *src)
 const char *
 qemuBlockStorageSourceGetEffectiveStorageNodename(virStorageSource *src)
 {
-    if (src->sliceStorage &&
-        src->sliceStorage->nodename)
-        return src->sliceStorage->nodename;
+    const char *slice = qemuBlockStorageSourceGetSliceNodename(src);
+
+    if (slice)
+        return slice;
 
     return src->nodenamestorage;
 }

src/qemu/qemu_block.h

@@ -40,6 +40,9 @@ qemuBlockStorageSourceGetEffectiveStorageNodename(virStorageSource *src);
 const char *
 qemuBlockStorageSourceGetStorageNodename(virStorageSource *src);
 
+const char *
+qemuBlockStorageSourceGetSliceNodename(virStorageSource *src);
+
 const char *
 qemuBlockStorageSourceGetFormatNodename(virStorageSource *src);