Casey Schaufler [off-list ref] wrote:

The authors of this version of the mount code failed to look
especially closely at how Smack maintains label names. Once a
label name is used in the kernel it is kept on a list forever.
All the copies of smk_known here and in the rest of the mount
infrastructure are unnecessary and wasteful. The entire set of
Smack hooks that deal with mounting need to be reworked to remove
that waste. It's on my list of Smack cleanups, but I'd be happy
if someone else wanted a go at it.

I don't have time to overhaul Smack right now.  Should I drop the Smack part
of the patch?

David