mkdir() ... (sidebar on 4.2)

[David Collier-Brown]

>From article <10845 at swan.ulowell.edu>, by arosen at hawk.ulowell.edu (MFHorn):
> A couple years ago, I had to fix this bug in one of our systems.  I had
> source to mkdir.c, but not to the kernel, and was able to successfully
> close the hole completely.

  Just a sidebar on the presumed safety of Berkeley 4.2:  
while creating old-fashioned lock files on an Ultrix system, I noted
that at least the rename system call was non-atomic (ie, I could
observe both the old and new names for a few repetitions of ls -l),
and wonder if a similar situation applies to the mkdir operation.
  --dave (I'll try it on my sun next year (:-)) c-b
-- 
 David Collier-Brown.  | yunexus!lethe!dave
 Interleaf Canada Inc. |
 1550 Enterprise Rd.   | He's so smart he's dumb.
 Mississauga, Ontario  |       --Joyce C-B