From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pat LaVarre Subject: Re: zeroes read back more often than appended Date: 11 Dec 2003 11:42:30 -0700 Sender: linux-fsdevel-owner@vger.kernel.org Message-ID: <1071168150.2503.6.camel@patibmrh9> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from email-out1.iomega.com ([147.178.1.82]:26310 "EHLO email.iomega.com") by vger.kernel.org with ESMTP id S265210AbTLKSmh (ORCPT ); Thu, 11 Dec 2003 13:42:37 -0500 Received: from royntex01.iomegacorp.com (unknown [147.178.90.120]) by email.iomega.com (Postfix) with ESMTP id A6E821D0C for ; Thu, 11 Dec 2003 11:42:36 -0700 (MST) To: linux-fsdevel@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org > From: [offline] > Date: Thu, 4 Dec 2003 16:28:59 -0700 > To: p.lavarre@ieee.org > ... > bs = 4096 (or whatever) > data[bs] > for i 1-60 > seek (i*2*bs) > write(data) In less than a second, writing a /dev/loop0 toy volume of about 0.001 GiB this way breaks 2.6.0-test11 udf.ko via "fs/udf/balloc.c:192:" "udf_bitmap_free_blocks: bit ... already set". Here this test breaks udf.ko for bs in 2048 4096, loop in 1..60, writing zero or nonzero. The resulting file is hole, hole, write, hole, write, .... Here this test does Not break udf.ko for bs in 2047 2049, for loop in 0..60 0..59 1..59. Pat LaVarre