[libvirt] [PATCH] snapshot: forbid snapshot on autodestroy domain

[Daniel Veillard]

On Fri, Aug 26, 2011 at 05:35:34PM -0600, Eric Blake wrote:
> There is no reason to forbid pausing an autodestroy domain
> (not to mention that 'virsh start --paused --autodestroy'
> succeeds in creating a paused autodestroy domain).
> 
> Meanwhile, qemu was failing to enforce the API documentation that
> autodestroy domains cannot be saved.  And while the original
> documentation only mentioned save/restore, snapshots are another
> form of saving that are close enough in semantics as to make no
> sense on one-shot domains.
> 
> * src/qemu/qemu_driver.c (qemudDomainSuspend): Drop bogus check.
> (qemuDomainSaveInternal, qemuDomainSnapshotCreateXML): Forbid
> saves of autodestroy domains.
> * src/libvirt.c (virDomainCreateWithFlags, virDomainCreateXML):
> Document snapshot interaction.
> ---
> 
> Sending this one separately for v1, but I'll insert it into the
> front of my snapshot series (before 1/43) when I post v4 of that.
> 
>  src/libvirt.c          |    4 ++--
>  src/qemu/qemu_driver.c |   18 ++++++++++++------
>  2 files changed, 14 insertions(+), 8 deletions(-)
> 
> diff --git a/src/libvirt.c b/src/libvirt.c
> index 65a099b..711580e 100644
> --- a/src/libvirt.c
> +++ b/src/libvirt.c
> @@ -1822,7 +1822,7 @@ virDomainGetConnect (virDomainPtr dom)
>   * object is finally released. This will also happen if the
>   * client application crashes / loses its connection to the
>   * libvirtd daemon. Any domains marked for auto destroy will
> - * block attempts at migration or save-to-file
> + * block attempts at migration, save-to-file, or snapshots.
>   *
>   * Returns a new domain object or NULL in case of failure
>   */
> @@ -7073,7 +7073,7 @@ error:
>   * object is finally released. This will also happen if the
>   * client application crashes / loses its connection to the
>   * libvirtd daemon. Any domains marked for auto destroy will
> - * block attempts at migration or save-to-file
> + * block attempts at migration, save-to-file, or snapshots.
>   *
>   * If the VIR_DOMAIN_START_BYPASS_CACHE flag is set, and there is a
>   * managed save file for this domain (created by virDomainManagedSave()),
> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index f21122d..737eec8 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -1360,12 +1360,6 @@ static int qemudDomainSuspend(virDomainPtr dom) {
>          goto cleanup;
>      }
> 
> -    if (qemuProcessAutoDestroyActive(driver, vm)) {
> -        qemuReportError(VIR_ERR_OPERATION_INVALID,
> -                        "%s", _("domain is marked for auto destroy"));
> -        goto cleanup;
> -    }
> -
>      priv = vm->privateData;
> 
>      if (priv->job.asyncJob == QEMU_ASYNC_JOB_MIGRATION_OUT) {
> @@ -2225,6 +2219,12 @@ qemuDomainSaveInternal(struct qemud_driver *driver, virDomainPtr dom,
>      int directFlag = 0;
>      virFileDirectFdPtr directFd = NULL;
> 
> +    if (qemuProcessAutoDestroyActive(driver, vm)) {
> +        qemuReportError(VIR_ERR_OPERATION_INVALID,
> +                        "%s", _("domain is marked for auto destroy"));
> +        return -1;
> +    }
> +
>      memset(&header, 0, sizeof(header));
>      memcpy(header.magic, QEMUD_SAVE_MAGIC, sizeof(header.magic));
>      header.version = QEMUD_SAVE_VERSION;
> @@ -8471,6 +8471,12 @@ static virDomainSnapshotPtr qemuDomainSnapshotCreateXML(virDomainPtr domain,
>          goto cleanup;
>      }
> 
> +    if (qemuProcessAutoDestroyActive(driver, vm)) {
> +        qemuReportError(VIR_ERR_OPERATION_INVALID,
> +                        "%s", _("domain is marked for auto destroy"));
> +        goto cleanup;
> +    }
> +
>      /* in a perfect world, we would allow qemu to tell us this.  The problem
>       * is that qemu only does this check device-by-device; so if you had a
>       * domain that booted from a large qcow2 device, but had a secondary raw

 ACK,

Daniel

-- 
Daniel Veillard      | libxml Gnome XML XSLT toolkit  http://xmlsoft.org/
daniel at veillard.com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/