[libvirt] [PATCH] qemu: snapshot: inactive external snapshot can't work after libvirtd restart

[John Ferlan]

On 12/06/2014 11:32 AM, Shanzhi Yu wrote:
> When create inactive external snapshot, after update disk definitions,
> virDomainSaveConfig is needed, if not after restart libvirtd the new snapshot
> file definitions in xml will be lost.
> 
> Reproduce steps:
> 
> 1. prepare a shut off guest
> $ virsh domstate rhel7 && virsh domblklist rhel7
> shut off
> 
> Target     Source
> ------------------------------------------------
> vda        /var/lib/libvirt/images/rhel7.img
> 
> 2. create external disk snapshot
> $ virsh snapshot-create rhel7 --disk-only && virsh domblklist rhel7
> Domain snapshot 1417882967 created
> Target     Source
> ------------------------------------------------
> vda        /var/lib/libvirt/images/rhel7.1417882967
> 
> 3. restart libvirtd then check guest source file
> $ service  libvirtd restart && virsh domblklist rhel7
> Redirecting to /bin/systemctl restart  libvirtd.service
> Target     Source
> ------------------------------------------------
> vda        /var/lib/libvirt/images/rhel7.img
> 
> This was first reported by Eric Blake
> http://www.redhat.com/archives/libvir-list/2014-December/msg00369.html
> 
> Signed-off-by: Shanzhi Yu <shyu at redhat.com>
> ---
>  src/qemu/qemu_driver.c | 3 +++
>  1 file changed, 3 insertions(+)
> 

Looks like this one may have been lost in the shuffle prior to the
holidays...

Seems reasonable to me - although I'll wait a bit before pushing just in
case by popping it to the top of the stack again it causes more
discussion...

John
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index 9152cf5..9f8ea0a 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -12847,6 +12847,9 @@ qemuDomainSnapshotCreateInactiveExternal(virQEMUDriverPtr driver,
>                  goto cleanup;
>              }
>              defdisk->src->format = snapdisk->src->format;
> +
> +            if (virDomainSaveConfig(cfg->configDir, vm->def) < 0)
> +                goto cleanup;
>          }
>      }
>  
>