On Thu, Oct 21, 2010 at 09:56:48PM -0500, Ryan Harper wrote:
> Currently libvirt doesn't confirm whether the guest has responded to the
> disk removal request. In some cases this can leave the guest with
> continued access to the device while the mgmt layer believes that it has
> been removed. With a recent qemu monitor command[1] we can
> deterministically revoke a guests access to the disk (on the QEMU side)
> to ensure no futher access is permitted.
>
> This patch adds support for the drive_unplug() command and introduces it
> in the disk removal paths. There is some discussion to be had about how
> to handle the case where the guest is running in a QEMU without this
> command (and the fact that we currently don't have a way of detecting
> what monitor commands are available).
>
> Changes since v1:
> - return > 0 when command isn't present, < 0 on command failure
> - detect when drive_unplug command isn't present and log error
> instead of failing entire command
>
> Signed-off-by: Ryan Harper <ryanh@xxxxxxxxxx>
> +int qemuMonitorJSONDriveUnplug(qemuMonitorPtr mon,
> + const char *drivestr)
> +{
> +
> + if (ret == 0) {
> + /* See if drive_unplug isn't supported */
> + if (qemuMonitorJSONHasError(reply, "CommandNotFound")) {
> + qemuReportError(VIR_ERR_OPERATION_FAILED, "%s",
> + _("unplugging disk is not supported. "
> + "This may leak data if disk is reassigned"));
> + ret = 1;
> + goto cleanup;
> + }
> + ret = qemuMonitorJSONCheckError(cmd, reply);
> + }
>
> +/* Attempts to unplug a drive. Returns 1 if unsupported, 0 if ok, and -1 on
> + * other failure */
> +int qemuMonitorTextDriveUnplug(qemuMonitorPtr mon,
> + const char *drivestr)
> +{
> +
> + if (strstr(reply, "unknown command:")) {
> + qemuReportError(VIR_ERR_OPERATION_FAILED, "%s",
> + _("unplugging disk is not supported. "
> + "This may leak data if disk is reassigned"));
> + ret = 1;
> + goto cleanup;
For these 2 non-fatal errors, qemuReportError shouldn't be used. Instead
just directly call VIR_WARN or VIR_ERROR logging functions
Regards,
Daniel
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