This patch adds support for getting the usage of mounted
filesystem.
The usage of fs stored as used_bytes and total_bytes.
It's very useful when we try to monitor guest's filesystem.
Cc: Michael Roth <mdroth@linux.vnet.ibm.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
25b5ff1a86