[libvirt PATCH 15/20] qemu_snapshot: delete: properly update parent snapshot with revert data

[Peter Krempa]

On Mon, Mar 13, 2023 at 16:42:16 +0100, Pavel Hrdina wrote:
> When deleting external snapshot and parent snapshot is the currently
> active snapshot as user reverted to it we need to properly update the
> parent snapshot metadata.
> 
> After the delete is done the new overlay files will be the currently
> used files created when snapshot revert was done, replacing the original
> overlay files.
> 
> Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
> ---
>  src/qemu/qemu_snapshot.c | 40 ++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 40 insertions(+)
> 
> diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
> index dbcdf56758..513bcb5a86 100644
> --- a/src/qemu/qemu_snapshot.c
> +++ b/src/qemu/qemu_snapshot.c
> @@ -3063,6 +3063,41 @@ qemuSnapshotDiscardExternal(virDomainObj *vm,
>  }
>  
>  
> +static int
> +qemuSnapshotDeleteUpdateParent(virDomainObj *vm,
> +                               virDomainMomentObj *parent)
> +{
> +    size_t i;
> +    virQEMUDriver *driver = ((qemuDomainObjPrivate *) vm->privateData)->driver;

You can use QEMU_DOMAIN_PRIVATE(vm)->driver here to hide the typecast.

> +    g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(driver);
> +    virDomainSnapshotDef *parentDef = virDomainSnapshotObjGetDef(parent);
> +
> +    if (!parentDef)
> +        return 0;
> +
> +    if (!parentDef->revertdisks)
> +        return 0;

Reviewed-by: Peter Krempa <pkrempa at redhat.com>