You can post a share-your-knowledge style question and answer. Say, the question would look like:

> How can I find out what's blocking my access to a particular PATH?

With some back story and a preface and all. And then post your script in your answer, with a good explanation on *how it works* and its usage.

At which point, I'll post another answer pointing to [`namei`][1]:

    $ namei -movx /var/spool/cron/crontabs/foo
    f: /var/spool/cron/crontabs/foo
    Drwxr-xr-x root root    /
    drwxr-xr-x root root    var
    drwxr-xr-x root root    spool
    drwxr-xr-x root root    cron
    drwx-wx--T root crontab crontabs
    foo - No such file or directory

It doesn't list what's mounted on a mountpoint, but everything else is covered, I think.

  [1]: http://manpages.ubuntu.com/namei.1