Re: Zmailer and Majordomo troubles

[smurf@noris.de (Matthias Urlichs)]

Matti Aarnio <mea@utu.fi> writes (in the zmailer list):
> 
> 	I will ask about it in the Linux kernel forum.  (browsing kernel
> 	source just tells me that it is prone to do surprises..  It looks
> 	to me that a file open for RDWR will always be updated both atime,
> 	and mtime even if only really written to..)
> 
File access happens in page-sized chunks. This basically means that if you
want to write to the end of a file, you usually have to read the last
(partial) page of that file. The kernel formerly did that for you,
invisibly.

Linux exposes that problem to the program because it uses the page cache
for file access. Since there is no write-only mapping of pages on the x86,
there is a problem... I suppose Linus will come up with a clever fix with
the next kernel version. ;-)

-- 
At Sun, we don't believe in the Soviet model of economic planning. 
	-- Bill Joy
-- 
Matthias Urlichs        \ XLink-POP Nürnberg  | EMail: urlichs@smurf.noris.de
Schleiermacherstraße 12  \  Unix+Linux+Mac    | Phone: ...please use email.
90491 Nürnberg (Germany)  \   Consulting+Networking+Programming+etc'ing     42
          PGP: 1B 89 E2 1C 43 EA 80 44  15 D2 29 CF C6 C7 E0 DE 
       Click <A HREF="http://smurf.noris.de/~smurf/finger">here</A>.