Re: NFS in 2.1.130??

Ben Gertzfield (
02 Dec 1998 08:47:12 -0800

>>>>> "David" == David Luyer <> writes:

Alan> procmail style dot locking works over NFS.

Chip> So does Deliver, if it's compiled with -DHAS_NFS.
Chip> Unfortunately, the Debian distribution of Deliver isn't. So
Chip> I recommend that Debian users of Deliver compile it on their
Chip> own.

David> Especially as the default 'deliver' does flock() locking,
David> the default 'qpopper' does fcntl() locking (flock() but
David> with a flock.c which really does fcntl()) and the net
David> result is large amounts of mail bounces which sendmail
David> doesn't handle well and bounces a whole mass of messages
David> when it sees the first error. So yes, Debian users should
David> compile their own deliver and/or qpopper and/or other mail
David> programs. This is one area Debian is currently lacking -
David> there's no "Debian mail locking standard" evident.

This is patently untrue; deliver was mistakenly not conformant with
Debian Mail Transport Agent policy, but Debian most certainly does
have a specific set of guidelines on how MTAs must behave:

5.5 Mail transport agents

Debian packages which process electronic mail, whether
mail-user-agents (MUAs) or mail-transport-agents (MTAs), must make
sure that they are compatible with the configuration decisions
below. Failure to do this may result in lost mail, broken From: lines,
and other serious brain damage!

The mail spool is /var/spool/mail and the interface to send a mail
message is /usr/sbin/sendmail (as per the FSSTND). The mail spool is
part of the base system and not part of the MTA package.

All Debian MUAs and MTAs have to use the maillock and mailunlock
functions provided by the liblockfile packages to lock and unlock mail
boxes. These functions implement a NFS-safe locking mechanism. (It is
ok if MUAs and MTAs don't link against liblockfile but use a
compatible mechanism. Please compare the mechanisms very carefully!)


So there you go -- we actually provide a library, liblockfile, to get
consistant locking behavior that is safe across NFS; if the MTA cannot
be linked against liblockfile, a compatible mechanism (i.e. dotfiles)
must be used.

David> Debian's 'deliver' also doesn't send comsat ("biff")
David> messages. I have a patch if anyone's interested and able
David> to get it into 'deliver', since all addresses in the source
David> code end up in mail bounces.

Please mail your patch to the Debian bug-tracking system; to submit
a patch on the deliver package, simply mail to
and make the first line of your message, after the headers:

Package: deliver

If you include your patch with the bug report, the Debian maintainer
can certainly contact the upstream source. Debian maintainers
generally have been in contact already with upstream and know the best
address to reach them.


Brought to you by the letters A and C and the number 1.
"Everybody wants prosthetic foreheads on their real heads." -- TMBG
Debian GNU/Linux -- where do you want to go tomorrow?
I'm on FurryMUCK as Che, and EFNet and YiffNet IRC as Che_Fox.

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to Please read the FAQ at