From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pat LaVarre Subject: Re: zeroes read back more often than appended Date: 28 Nov 2003 11:29:39 -0700 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <1070044179.3531.19.camel@patrh9> References: <1069346480.6663.37.camel@patrh9> <1069893904.4318.18.camel@patrh9> <1070043646.3531.17.camel@patrh9> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from email-out1.iomega.com ([147.178.1.82]:24565 "EHLO email.iomega.com") by vger.kernel.org with ESMTP id S263388AbTK1SaK (ORCPT ); Fri, 28 Nov 2003 13:30:10 -0500 Received: from royntex01.iomegacorp.com (unknown [147.178.90.120]) by email.iomega.com (Postfix) with ESMTP id 61B72248E for ; Fri, 28 Nov 2003 11:30:09 -0700 (MST) To: linux-fsdevel@vger.kernel.org In-Reply-To: <1070043646.3531.17.camel@patrh9> List-Id: linux-fsdevel.vger.kernel.org // To recap now, next game suggested is: CONFIG_DEBUG_KERNEL=y CONFIG_DEBUG_INFO=y CONFIG_DEBUG_SLAB=y CONFIG_MAGIC_SYSRQ=y gdb /usr/src/linux/vmlinux /proc/kcore // We're motivated to play because when we try // appending nonzero to files, then we see: "Two files with mkudffs, reads zeroes from both files ouch." "One file with mkudffs, ok" if and only if CONFIG_SMP = CONFIG_PREEMPT = off. "Two files with mkfs in place of mkudffs, ok." // To reproduce these results involves such // steps as the following. // // Reliably reproducing this trouble as yet // requires whole minutes of real time from a PC // that can rebuild the defconfig kernel in // about six minutes. http://sourceforge.net/projects/linux-udf/ ftp://members.aol.com/plscsi/linux/udftools-cvs.2003-11-26.tar.gz mkdir /mnt/loop0 ln -s /sbin/losetup ~/bin ln -s $PWD/mkudffs ~/bin cd ~/bin patch