From 3323e85bf659d47564bb85342c0a99aceac82a8f Mon Sep 17 00:00:00 2001
From: Peter Krempa <pkrempa@redhat.com>
Date: Thu, 12 Dec 2019 15:20:48 +0100
Subject: [PATCH] qemu: backup: Extract calculations of bitmaps to merge for
 incremental backup

Separate the for now incomplete code that collects the bitmaps to be
merged for an incremental backup into a separate function. This will
allow adding testing prior to the improvement of the algorithm to
include snapshots.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 src/qemu/qemu_backup.c | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/src/qemu/qemu_backup.c b/src/qemu/qemu_backup.c
index 1cd466d211..31949b5399 100644
--- a/src/qemu/qemu_backup.c
+++ b/src/qemu/qemu_backup.c
@@ -170,6 +170,30 @@ qemuBackupDiskDataCleanup(virDomainObjPtr vm,
 }
 
 
+static virJSONValuePtr
+qemuBackupDiskPrepareOneBitmapsChain(virDomainMomentDefPtr *incremental,
+                                     virStorageSourcePtr backingChain)
+{
+    g_autoptr(virJSONValue) ret = NULL;
+
+    if (!(ret = virJSONValueNewArray()))
+        return NULL;
+
+    /* TODO: this code works only if the bitmaps are present on a single node.
+     * The algorithm needs to be changed so that it looks into the backing chain
+     * so that we can combine all relevant bitmaps for a given backing chain */
+    while (*incremental) {
+        if (qemuMonitorTransactionBitmapMergeSourceAddBitmap(ret,
+                                                             backingChain->nodeformat,
+                                                             (*incremental)->name) < 0)
+            return NULL;
+
+        incremental++;
+    }
+
+    return g_steal_pointer(&ret);
+}
+
 
 static int
 qemuBackupDiskPrepareOneBitmaps(struct qemuBackupDiskData *dd,
@@ -179,21 +203,10 @@ qemuBackupDiskPrepareOneBitmaps(struct qemuBackupDiskData *dd,
     g_autoptr(virJSONValue) mergebitmaps = NULL;
     g_autoptr(virJSONValue) mergebitmapsstore = NULL;
 
-    if (!(mergebitmaps = virJSONValueNewArray()))
+    if (!(mergebitmaps = qemuBackupDiskPrepareOneBitmapsChain(incremental,
+                                                              dd->domdisk->src)))
         return -1;
 
-    /* TODO: this code works only if the bitmaps are present on a single node.
-     * The algorithm needs to be changed so that it looks into the backing chain
-     * so that we can combine all relevant bitmaps for a given backing chain */
-    while (*incremental) {
-        if (qemuMonitorTransactionBitmapMergeSourceAddBitmap(mergebitmaps,
-                                                             dd->domdisk->src->nodeformat,
-                                                             (*incremental)->name) < 0)
-            return -1;
-
-        incremental++;
-    }
-
     if (!(mergebitmapsstore = virJSONValueCopy(mergebitmaps)))
         return -1;