libblkid: Idea to force given cached entry to be invalidated?

[Qu Wenruo <quwenruo@cn.fujitsu.com>]

Hi,

When using the blkid_get_cache(), things will be cached to reduce the 
probe frequency.

But filesystem which supports device management like btrfs can remove 
device and
if fast enough, libblkid will not invalidate the old cache and cause to 
get the wrong filesystem type.

The bug is describe in the following btrfs patch:
https://patchwork.kernel.org/patch/3960191/

Though the above patch try to avoid the whole cache, it's not good 
enough since it break the pricible not
to probe the devices too frequently.

After some searching, it seems that libblkid does not provide such API, 
or am I missing something?

So is there any idea about forcing given cached entry invalidated?

Thanks,
Qu