Couldn't we just use a dummy mount? Bind mount /bin/ as /tmp/`mktemp
-d`/, then test retval=diropen(/tmp/`mktemp`)? (Or
fopen("/tmp/`mktemp`/ls") or sth similar).
(I didn't say it was clean ... :) But this test is probably better
than nothing, as it prevents /dev/ from being unusable. Just abstract
the test to some bashscript or a few lines of C, stick it in
/usr/lib/udev/ until some point when the kernel tells the truth.
Justin