diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index fbaf16704b..c03b769c37 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1691,7 +1691,7 @@ virStorageSourceChainLookup;
 virStorageSourceChown;
 virStorageSourceCreate;
 virStorageSourceDeinit;
-virStorageSourceGetBackingStoreStr;
+virStorageSourceFetchRelativeBackingPath;
 virStorageSourceGetMetadata;
 virStorageSourceGetMetadataFromBuf;
 virStorageSourceGetMetadataFromFD;
diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c
index d845a3312d..6456100170 100644
--- a/src/qemu/qemu_block.c
+++ b/src/qemu/qemu_block.c
@@ -3420,7 +3420,6 @@ qemuBlockUpdateRelativeBacking(virDomainObjPtr vm,
     virStorageSourcePtr n;
 
     for (n = src; virStorageSourceHasBacking(n); n = n->backingStore) {
-        g_autofree char *backingStoreStr = NULL;
         int rc;
 
         if (n->backingStore->relPath)
@@ -3432,15 +3431,12 @@ qemuBlockUpdateRelativeBacking(virDomainObjPtr vm,
         if (qemuDomainStorageFileInit(driver, vm, n, topsrc) < 0)
             return -1;
 
-        rc = virStorageSourceGetBackingStoreStr(n, &backingStoreStr);
+        rc = virStorageSourceFetchRelativeBackingPath(n, &n->backingStore->relPath);
 
         virStorageSourceDeinit(n);
 
         if (rc < 0)
             return rc;
-
-        if (backingStoreStr && virStorageIsRelative(backingStoreStr))
-            n->backingStore->relPath = g_steal_pointer(&backingStoreStr);
     }
 
     return 0;
diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index bfc5a1a46b..39445738a2 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -1088,16 +1088,9 @@ qemuSnapshotDiskPrepareOne(virDomainObjPtr vm,
         dd->initialized = true;
 
         if (reuse) {
-            if (updateRelativeBacking) {
-                g_autofree char *backingStoreStr = NULL;
-
-                if (virStorageSourceGetBackingStoreStr(dd->src, &backingStoreStr) < 0)
-                    return -1;
-                if (backingStoreStr != NULL) {
-                    if (virStorageIsRelative(backingStoreStr))
-                        dd->relPath = g_steal_pointer(&backingStoreStr);
-                }
-            }
+            if (updateRelativeBacking &&
+                virStorageSourceFetchRelativeBackingPath(dd->src, &dd->relPath) < 0)
+                return -1;
         } else {
             /* pre-create the image file so that we can label it before handing it to qemu */
             if (supportsCreate && dd->src->type != VIR_STORAGE_TYPE_BLOCK) {
diff --git a/src/storage_file/storage_source.c b/src/storage_file/storage_source.c
index 430e3214c4..23d36507ea 100644
--- a/src/storage_file/storage_source.c
+++ b/src/storage_file/storage_source.c
@@ -1881,24 +1881,26 @@ virStorageSourceGetRelativeBackingPath(virStorageSourcePtr top,
 
 
 /**
- * virStorageSourceGetBackingStoreStr:
+ * virStorageSourceFetchRelativeBackingPath:
  * @src: storage object
+ * @relPath: filled with the relative path to the backing image of @src if
+ *           the metadata of @src refer to it as relative.
  *
- * Extracts the backing store string as stored in the storage volume described
- * by @src and returns it to the user. Caller is responsible for freeing it.
- * In case when the string can't be retrieved or does not exist NULL is
- * returned.
+ * Fetches the backing store definition of @src by updating the metadata from
+ * disk and fills 'relPath' if the backing store string is relative. The data
+ * is used by virStorageSourceGetRelativeBackingPath to establish the relative
+ * path between two images.
  */
 int
-virStorageSourceGetBackingStoreStr(virStorageSourcePtr src,
-                                   char **backing)
+virStorageSourceFetchRelativeBackingPath(virStorageSourcePtr src,
+                                         char **relPath)
 {
     ssize_t headerLen;
     int rv;
     g_autofree char *buf = NULL;
     g_autoptr(virStorageSource) tmp = NULL;
 
-    *backing = NULL;
+    g_clear_pointer(relPath, g_free);
 
     /* exit if we can't load information about the current image */
     if (!virStorageSourceSupportsBackingChainTraversal(src))
@@ -1925,7 +1927,9 @@ virStorageSourceGetBackingStoreStr(virStorageSourcePtr src,
     if (virStorageFileProbeGetMetadata(tmp, buf, headerLen) < 0)
         return -1;
 
-    *backing = g_steal_pointer(&tmp->backingStoreRaw);
+    if (virStorageIsRelative(tmp->backingStoreRaw))
+        *relPath = g_steal_pointer(&tmp->backingStoreRaw);
+
     return 0;
 }
 
diff --git a/src/storage_file/storage_source.h b/src/storage_file/storage_source.h
index 480333d37a..58f88a3c01 100644
--- a/src/storage_file/storage_source.h
+++ b/src/storage_file/storage_source.h
@@ -138,8 +138,8 @@ virStorageSourceGetMetadata(virStorageSourcePtr src,
     ATTRIBUTE_NONNULL(1);
 
 int
-virStorageSourceGetBackingStoreStr(virStorageSourcePtr src,
-                                   char **backing)
+virStorageSourceFetchRelativeBackingPath(virStorageSourcePtr src,
+                                         char **relPath)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
 void