From owner-freebsd-stable@FreeBSD.ORG Fri Sep 19 12:36:02 2008 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 352591065682 for ; Fri, 19 Sep 2008 12:36:02 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from QMTA06.emeryville.ca.mail.comcast.net (qmta06.emeryville.ca.mail.comcast.net [76.96.30.56]) by mx1.freebsd.org (Postfix) with ESMTP id 1BB4F8FC17 for ; Fri, 19 Sep 2008 12:36:02 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from OMTA01.emeryville.ca.mail.comcast.net ([76.96.30.11]) by QMTA06.emeryville.ca.mail.comcast.net with comcast id GajA1a0020EPchoA6cc1DA; Fri, 19 Sep 2008 12:36:01 +0000 Received: from koitsu.dyndns.org ([67.180.253.227]) by OMTA01.emeryville.ca.mail.comcast.net with comcast id Gcbz1a00A4v8bD78McbzZZ; Fri, 19 Sep 2008 12:36:00 +0000 X-Authority-Analysis: v=1.0 c=1 a=QycZ5dHgAAAA:8 a=IpJzsrvF0OYJwm-xvNgA:9 a=wROprSuifKPDRVhnchgA:7 a=0BYlPyXxTZqgEsZNUm33iC8NUXEA:4 a=EoioJ0NPDVgA:10 a=LY0hPdMaydYA:10 Received: by icarus.home.lan (Postfix, from userid 1000) id 5100517B81A; Fri, 19 Sep 2008 05:35:59 -0700 (PDT) Date: Fri, 19 Sep 2008 05:35:59 -0700 From: Jeremy Chadwick To: freebsd-stable@FreeBSD.ORG, talon@lpthe.jussieu.fr, jhb@FreeBSD.ORG Message-ID: <20080919123559.GA45054@icarus.home.lan> References: <20080918183250.GA48347@lpthe.jussieu.fr> <200809190955.m8J9t5mE092126@lurza.secnetix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200809190955.m8J9t5mE092126@lurza.secnetix.de> User-Agent: Mutt/1.5.18 (2008-05-17) Cc: Subject: Re: floppy disk controller broken X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 19 Sep 2008 12:36:02 -0000 On Fri, Sep 19, 2008 at 11:55:05AM +0200, Oliver Fromme wrote: > Michel Talon wrote: > > Oliver Fromme wrote: > > > Michel Talon wrote: > > > > Moreover, trying to write to the floppy: > > > > niobe# dd if=/dev/zero of=/dev/fd0 conv=noerror > > > > dd: /dev/fd0: Input/output error > > > > 5+0 records in > > > > 4+0 records out > > > > 2048 bytes transferred in 4.054404 secs (505 bytes/sec) > > > > > > > > I don't expect such result. Traditionnally writing works, while reading > > > > may fail. > > > > > > Maybe I misunderstand what you're saying, but ... > > > When I try to write to a floppy that has *not* been > > > successfully formatted, I very much expect to get > > > Input/output error. Anything else would be a bug. > > > > The floppy has certainly be formatted, in the past. Perhaps i > > remember badly, i have not used floppies since years, but > > in this case the behavior with Windows, Linux and ancient FreeBSD > > was that you could write to the floppy, but could encounter errors > > while reading. > > Since you mentioned "ancient" FreeBSD, I assume that was > using buffered block devices, when FreeBSD still supported > them? That sounds right -- again, if my memory hasn't failed me... > Nowadays /dev/fd0 is a character device which is > unbuffered, i.e. your dd(1) command goes straight to the > disk, and if the drive reports an error (typically sync > mark not found if the floppy is unformatted), it goes back > up to dd(1) immediately and you get Input/output error. Ah ha! Evolution has occurred. Thanks for educating me. :-) -- | Jeremy Chadwick jdc at parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |