----- "Eric Sandeen" <sandeen@xxxxxxxxxx> wrote:
> From: Lachlan McIlroy <lmcilory@xxxxxxxxxx>
lmcilroy - although I was briefly known as lmcilory due a HR error.
Eric, the test looks good to me, thanks for fixing the errors in it.
>
> 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 <sandeen@xxxxxxxxxx>
> ---
>
> #! /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@xxxxxxxxxx
>
> 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@xxxxxxxxxxx
http://oss.sgi.com/mailman/listinfo/xfs
