From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id oACMZdQt167764 for ; Fri, 12 Nov 2010 16:35:39 -0600 Received: from mx1.redhat.com (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 716F91751FA for ; Fri, 12 Nov 2010 14:37:09 -0800 (PST) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by cuda.sgi.com with ESMTP id ryrDM06cAAJddLSl for ; Fri, 12 Nov 2010 14:37:09 -0800 (PST) Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id oACMb8rO031681 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Fri, 12 Nov 2010 17:37:08 -0500 Message-ID: <4CDDC193.9030208@redhat.com> Date: Fri, 12 Nov 2010 16:37:07 -0600 From: Eric Sandeen MIME-Version: 1.0 Subject: [PATCH] xfstests 246: Test for race between direct I/O and mmap List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: xfs mailing list Cc: Lachlan McIlroy From: Lachlan McIlroy A customer reported a problem: If a process is using mmap to write to a file on an ext4 filesystem while another process is using direct I/O to write to the same file the first thread may receive a SIGBUS during a page fault. A SIGBUS occurs if the page fault tries to access a page that is entirely beyond the end of the file but in this test case that should not be happening. Signed-off-by: Eric Sandeen --- #! /bin/bash # FS QA Test No. 246 # # Test for race between direct I/O and mmap # #----------------------------------------------------------------------- # Copyright (c) 2010 Red Hat, Inc. All Rights Reserved. # # This program is free software; you can redistribute it and/or # modify it under the terms of the GNU General Public License as # published by the Free Software Foundation. # # This program is distributed in the hope that it would be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program; if not, write the Free Software Foundation, # Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA #----------------------------------------------------------------------- # # creator owner=lmcilroy@redhat.com seq=`basename $0` echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 7 15 _cleanup() { cd / rm -f $tmp.* $testfile wait } # get standard environment, filters and checks . ./common.rc . ./common.filter # real QA test starts here # Modify as appropriate. _supported_fs generic _supported_os Linux testfile=$TEST_DIR/$seq.$$ loops=500 iosize=1048576 # Initialise file dd if=/dev/zero of=$testfile bs=$iosize count=$loops &> /dev/null [ $? -ne 0 ] && exit sync # Direct I/O overwriter dd if=/dev/zero of=$testfile oflag=direct bs=$iosize count=$loops conv=notrunc &> /dev/null & [ $? -ne 0 ] && exit # Mmap writer start=`expr $loops - 1` for i in `seq $start -1 0` do offset=`expr $i \* $iosize` $XFS_IO_PROG -F -f -c "mmap -w $offset $iosize" -c "mwrite $offset $iosize" $testfile [ $? -ne 0 ] && exit done wait echo "Silence is golden." # success, all done status=0 exit _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs