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Path: utzoo!henry
From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: comp.bugs.4bsd,comp.unix.wizards
Subject: Re: concurrent write(2) calls write bad data to file
Message-ID: <7778@utzoo.UUCP>
Date: Mon, 16-Mar-87 13:08:16 EST
Article-I.D.: utzoo.7778
Posted: Mon Mar 16 13:08:16 1987
Date-Received: Mon, 16-Mar-87 13:08:16 EST
References: <692@rtech.UUCP>, <14589@sun.uucp>
Organization: U of Toronto Zoology
Lines: 11

> I don't see any obvious reason why this *couldn't* happen on any
> UNIX system that didn't lock the file table entry while a write was
> in progress...  It may be that ... it's *less
> likely* to happen on a system using the V7 file system, but I don't
> see that it's impossible on such a system.

Not impossible at all.  Running the posted test program on utzoo (a vanilla
V7), some NULs show up.  Guy's explanation sounds right.
-- 
"We must choose: the stars or	Henry Spencer @ U of Toronto Zoology
the dust.  Which shall it be?"	{allegra,ihnp4,decvax,pyramid}!utzoo!henry