*BSD News Article 23013


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Newsgroups: comp.os.386bsd.questions
Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!agate!howland.reston.ans.net!xlink.net!subnet.sub.net!flatlin!bad
From: bad@flatlin.ka.sub.org (Christoph Badura)
Subject: Re: [BUG?] newfs with bsize = 16 kb ?
Date: Thu, 28 Oct 1993 20:54:44 GMT
Message-ID: <CFMKr8.MHo@flatlin.ka.sub.org>
References: <1993Oct23.193511.18122@Informatik.TU-Muenchen.DE> <CFGCts.FEB@flatlin.ka.sub.org> <1993Oct25.134010.14235@Informatik.TU-Muenchen.DE>
Organization: Guru Systems/Funware Department
Lines: 23

In <1993Oct25.134010.14235@Informatik.TU-Muenchen.DE> wiserner@Informatik.TU-Muenchen.DE (Bernd Wiserner) writes:
>Increasing MAXBSIZE is one point. The other is that it shouldn't crash my 
>OTHER disk however MAXBSIZE is set.( I made newfs on sd1 and it crashed sd0 ! )

You're right.  After a couple of e-mails with cgd we finally noticed
that you didn't mount the filesystem.  I apologize for not reading
your article carefully. I jumped to conclusions because I knew that
the buffer cache couldn't handle it with the standard MAXBSIZE.

As it turns out the routines spec_read and spec_write that handle all
IO through for special devices will request a buffer the size of the
filesystem block size as recorded in the disklabel for partitions
marked as containing FFS file systems.  This was in your case larger
than the buffer cache could handle.

While my advice to increas MAXBSIZE was correct, if I had carefully
read your article I'd noticed that the bug must be in spec_vnops.c.

-- 
Christoph Badura	bad@flatlin.ka.sub.org		+49 721 606137

The GOTO is back, and not only in the pages of the ACM Forum! The Ollie North
of language commands is turning up ... -- D.Foster, CACM V30#8 p. 659