[libvirt] [PATCH 3/3] qemu: backup: Implement support for backup disk bitmap name configuration

[Eric Blake]

On 1/9/20 12:31 PM, Peter Krempa wrote:
> Use the user-configured name of the bitmap when merging the appropriate
> bitmaps for an incremental backup so that the user can see it as
> configured. Additionally expose the default bitmap name if nothing is
> configured.
> 
> Signed-off-by: Peter Krempa <pkrempa at redhat.com>
> ---
>   src/qemu/qemu_backup.c | 9 ++++++++-
>   1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/src/qemu/qemu_backup.c b/src/qemu/qemu_backup.c
> index 2cc0e6ab07..23518a5d40 100644
> --- a/src/qemu/qemu_backup.c
> +++ b/src/qemu/qemu_backup.c
> @@ -322,7 +322,10 @@ qemuBackupDiskPrepareDataOne(virDomainObjPtr vm,
>           return -1;
> 
>       if (incremental) {
> -        dd->incrementalBitmap = g_strdup_printf("backup-%s", dd->domdisk->dst);
> +        if (dd->backupdisk->exportbitmap)
> +            dd->incrementalBitmap = g_strdup(dd->backupdisk->exportbitmap);

Do we need to worry about the user requesting a name that would cause 
conflicts with existing bitmaps in the qcow2 file?  I'm worried this can 
open the door for odd failures if the user accidentally stomps on names 
that libvirt thought were available for its own use.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org