Robert Brewer on Tue 1/05 16:59 -1000:
> I'm upgrading our qpopper from 3.0 to 4.0 in an attempt to improve
> performance. In particular, I'd like to be able to turn on server
> mode. However, some users on our system have shell accounts, and some
> do not. Therefore, I have to make sure that server mode is not turned
> on for shell users.
I don't know why the LX manual says continually that shell users
shouldn't be allowed access to server mode and the like...what they
should really say is, "don't let shell users have access to programs
that modify the mail spool and don't respect F_SETLK and/or dotlocks."
If you have been sure to compile all your programs to cooperate with
respec to fcntl()/flock() (which Qpopper does properly) then I don't see
where the problem would arise.
FWIW, any sane program from the last decade works appropriately with
locking (and they even work over NFS as long as you have NLM4 running).
If you're unsure, use `nm' to see if the symbols are there, and `strace'
to verify that the locks are being tested for, set where appropriate,
and honored.
