[libvirt] [PATCH] Check return value of qemuMonitorDriveDel.

[Daniel P. Berrange]

On Thu, Feb 17, 2011 at 02:32:49PM +0800, Hu Tao wrote:
> If we don't check it, virsh users will get "Disk detached successfully"
> even when qemuMonitorDriveDel fails.
> ---
>  src/qemu/qemu_hotplug.c      |   10 ++++++++--
>  src/qemu/qemu_monitor_json.c |    2 +-
>  2 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
> index fb9db5a..70e9d8e 100644
> --- a/src/qemu/qemu_hotplug.c
> +++ b/src/qemu/qemu_hotplug.c
> @@ -1187,7 +1187,10 @@ int qemuDomainDetachPciDiskDevice(struct qemud_driver *driver,
>      }
>  
>      /* disconnect guest from host device */
> -    qemuMonitorDriveDel(priv->mon, drivestr);
> +    if (qemuMonitorDriveDel(priv->mon, drivestr) != 0) {
> +        qemuDomainObjExitMonitor(vm);
> +        goto cleanup;
> +    }
>  
>      qemuDomainObjExitMonitorWithDriver(driver, vm);
>  
> @@ -1269,7 +1272,10 @@ int qemuDomainDetachSCSIDiskDevice(struct qemud_driver *driver,
>      }
>  
>      /* disconnect guest from host device */
> -    qemuMonitorDriveDel(priv->mon, drivestr);
> +    if (qemuMonitorDriveDel(priv->mon, drivestr) != 0) {
> +        qemuDomainObjExitMonitor(vm);
> +        goto cleanup;
> +    }

This needs to be  '< 0'.  0 indicates success, and '1' indicates
that the command was not available in qemu which we need to treat
as success too otherwise we cause a regression.

>      qemuDomainObjExitMonitorWithDriver(driver, vm);
>  
> diff --git a/src/qemu/qemu_monitor_json.c b/src/qemu/qemu_monitor_json.c
> index d5e8d37..b088405 100644
> --- a/src/qemu/qemu_monitor_json.c
> +++ b/src/qemu/qemu_monitor_json.c
> @@ -2338,7 +2338,7 @@ int qemuMonitorJSONDriveDel(qemuMonitorPtr mon,
>      if (ret == 0) {
>          /* See if drive_del isn't supported */
>          if (qemuMonitorJSONHasError(reply, "CommandNotFound")) {
> -            VIR_ERROR0(_("deleting disk is not supported.  "
> +            qemuReportError(VIR_ERR_NO_SUPPORT, _("deleting disk is not supported.  "
>                          "This may leak data if disk is reassigned"));

NACK to this chunk. We deliberately do not report an error when the
command is not found, because the 'drive_del' command does not exist
in any released QEMU yet and we don't want to cause a regression on
hotunplug for existing libvirt users.

>              ret = 1;
>              goto cleanup;


Daniel
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