[libvirt] [PATCH 2/2] qemu: Remove stale transient def when migration fails

[Peter Krempa]

On Thu, Sep 08, 2016 at 16:21:04 +0200, Jiri Denemark wrote:
> If a migration of a domain which is already defined on the destination
> host failed early (before we tried to start QEMU), we would forget to
> remove the incoming transient definition. Later on when someone starts
> the domain on the destination host, we will use the stale incoming
> definition and the persistent definition will just be ignored.
> 
> https://bugzilla.redhat.com/show_bug.cgi?id=1368774
> 
> Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
> ---
>  src/qemu/qemu_migration.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> index e451ef6..6ef2396 100644
> --- a/src/qemu/qemu_migration.c
> +++ b/src/qemu/qemu_migration.c
> @@ -3874,6 +3874,10 @@ qemuMigrationPrepareAny(virQEMUDriverPtr driver,
>          priv->nbdPort = 0;
>          qemuDomainRemoveInactive(driver, vm);
>      }
> +
> +    if (ret < 0)
> +        virDomainObjRemoveTransientDef(vm);

This needs to go to the block above. 'priv' is set if the domain def was
assigned (basically after virDomainObjListAdd) succeeded. Currently it
would crash if the target VM would be running. 'priv' basically
guarantees that 'vm' is valid.

ACK if you move this into the block above.