#!/bin/bash

# Each CPU reads every block off a block device...twice.

# Copyright (C) 2003-2006 IBM
#
# 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; either version 2 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will 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 to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
# 02111-1307, USA.


BLKDEVS=$(cat /proc/partitions | grep [sh]d.[0-9] | awk '{if ($3 > 10000)  print $4}')
WORK=$((NR_CPUS * 2))

echo "Running dd's on these devices:"
echo "$BLKDEVS"
echo "using $WORK dd's per device."

# Did we see any failures?
LOGFILE=/proc/$$/fd/1
OLD_ERRORS=`egrep -ic "(error|fail|invalid|denied|cannot)" $LOGFILE`

for ((k=1; k < $WORK; k++))
do
for i in $BLKDEVS
	do
		dd if=/dev/$i of=/dev/null bs=2k > /dev/null &
	done
done

# Wait for children
wait

# Did we see any failures?
NEW_ERRORS=`egrep -ic "(error|fail|invalid|denied|cannot)" $LOGFILE`
ERRORS=$(( NEW_ERRORS - OLD_ERRORS ))
if [ $ERRORS -eq 255 ]; then
	ERRORS=254
fi
exit $ERRORS