From: Thomas Koenig (ig25@fg70.rz.uni-karlsruhe.de)
Date: 01/29/93


From: ig25@fg70.rz.uni-karlsruhe.de (Thomas Koenig)
Subject: Re: 2 files with the same name in single directory, 0.99pl3, extfs
Date: 29 Jan 1993 16:03:35 GMT

torvalds@klaava.Helsinki.FI (Linus Torvalds) writes:

>To get two files with the same name you have to:

> - be low on memory. The buffer cache has to suffer real bad. Get
> linux swapping hard, and then start copying big files.
> - (at least) two processes trying to create the same file at once.

At the time this happened, I had a 16 MB system with about 6 Meg of
cache, no X running, and I only ran a single lpr - command at a time.
There may have been heavy disk activity at the same time, though; I was
doing some compilations the same evening, and of course I don't know
exactly when the second file was created.

A bug like that can lead to serious confusion with daemons when several
users on a heavily loaded machine are trying to put something into a
queue. Granted, this is not very bad on my personal box, where I have
root access, but for setting up a Linux machine here at our institute it
would be a serious drawback...

Question: Does file locking suffer from similar race conditions?

-- 
Thomas Koenig, ig25@rz.uni-karlsruhe.de, ig25@dkauni2.bitnet
The joy of engineering is to find a straight line on a double
logarithmic diagram.