[libvirt] [PATCH v3] qemu-migration: Disallow migration of read only disk

[Jason J. Herne]

Polite ping? :)

On 09/26/2016 01:16 PM, Corey S. McQuay wrote:
> Currently Libvirt allows attempts to migrate read only disks. Qemu cannot handle this as read only
> disks cannot be written to on the destination system. The end result is a cryptic error message
> and a failed migration.
>
> This patch causes migration to fail earlier and provides a meaningful error message stating that
> migrating read only disks is not supported.
>
> Signed-off-by: Corey S. McQuay <csmcquay at linux.vnet.ibm.com>
> Reviewed-by: Jason J. Herne <jjherne at linux.vnet.ibm.com>
> Reviewed-by: Boris Fiuczynski <fiuczy at linux.vnet.ibm.com>
> ---
>   src/qemu/qemu_migration.c | 6 ++++++
>   1 file changed, 6 insertions(+)
>
> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> index e451ef6..c8fb7ec 100644
> --- a/src/qemu/qemu_migration.c
> +++ b/src/qemu/qemu_migration.c
> @@ -1764,6 +1764,12 @@ qemuMigrationStartNBDServer(virQEMUDriverPtr driver,
>           /* check whether disk should be migrated */
>           if (!qemuMigrateDisk(disk, nmigrate_disks, migrate_disks))
>               continue;
> +
> +        if (disk->src->readonly) {
> +            virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
> +                        _("Cannot migrate read-only disk %s"), disk->dst);
> +            goto cleanup;
> +        }
>
>           VIR_FREE(diskAlias);
>           if (!(diskAlias = qemuAliasFromDisk(disk)))
>

-- 
-- Jason J. Herne (jjherne at linux.vnet.ibm.com)