qemu: backup: Add partial validation of incremental backup checkpoint

Verify that the checkpoint requested by an incremental backup exists.
Unfortunately validating whether the checkpoint configuration actually
matches the disk may not be reasonably feasible as the disk may have
been renamed/snapshotted/etc. We still rely on bitmap presence.

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

diff --git a/src/qemu/qemu_backup.c b/src/qemu/qemu_backup.c
index 2e3a2b2e3c50517a28cbf6bbd3cae591a18d3d04..99dee46c4fdd74e2d496473ed74a6528109526f1 100644 (file)
--- a/src/qemu/qemu_backup.c
+++ b/src/qemu/qemu_backup.c
@@ -277,6 +277,17 @@ qemuBackupDiskPrepareDataOne(virDomainObjPtr vm,
         return -1;
 
     if (dd->backupdisk->incremental) {
+        /* We deliberately don't check the config of the disk in the checkpoint
+         * definition as it's not guaranteed that the disks still correspond.
+         * We just verify that a checkpoint exists and later on that the disk
+         * has corresponding bitmap. */
+        if (!virDomainCheckpointFindByName(vm->checkpoints, dd->backupdisk->incremental)) {
+            virReportError(VIR_ERR_NO_DOMAIN_CHECKPOINT,
+                           _("Checkpoint '%s' for incremental backup of disk '%s' not found"),
+                           dd->backupdisk->incremental, dd->backupdisk->name);
+            return -1;
+        }
+
         if (dd->backupdisk->exportbitmap)
             dd->incrementalBitmap = g_strdup(dd->backupdisk->exportbitmap);
         else