Re: Zmailer and Majordomo troubles

Matthias Urlichs (smurf@smurf.noris.de)
Thu, 21 Mar 1996 13:06:14 +0100

Matti Aarnio <mea@utu.fi> writes (in the zmailer list):
>=20
> 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..)
>=20
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 cach=
e
for file access. Since there is no write-only mapping of pages on the x=
86,
there is a problem... I suppose Linus will come up with a clever fix wi=
th
the next kernel version. ;-)

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