#! /bin/bash
# FS QA Test No. 310
#
# Check if there are two threads,one keeps calling read() or lseek(), and
# the other calling readdir(), both on the same directory fd.
#
# Testing on ext3: with dir_index disabled results in the following
# dmesg output: (also occurs when testing ext2 and ext4)
#
# EXT3-fs error (device sdb): ext3_readdir: bad entry in directory #1134241:
# rec_len % 4 != 0 - offset=2704, inode=16973836, rec_len=12850, name_len=52
# EXT3-fs error (device sdb): ext3_readdir: bad entry in directory #1134241:
# directory entry across blocks - offset=1672, inode=16973836, rec_len=14132,
# name_len=57
#
# The filesystem mount option 'errors=' will define the behavior
# when an error is encountered. (see mount manpage)
#
# The test is based on a testcase from Li Zefan <lizefan@huawei.com>.
#
# http://marc.info/?l=linux-kernel&m=136123703211869&w=2
#
#-----------------------------------------------------------------------
# Copyright (c) 2013 HuaWei. 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
#-----------------------------------------------------------------------
#

seq=`basename $0`
seqres=$RESULT_DIR/$seq
echo "QA output created by $seq"

status=1	# failure is the default!

_cleanup()
{
	rm -rf $TEST_DIR/tmp
}
trap "_cleanup; exit \$status" 0 1 2 3 15

# get standard environment, filters and checks
. ./common/rc
. ./common/filter

# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_test
_require_command "$KILLALL_PROG" killall

dmesg -c > /dev/null

nr_bug=`dmesg | grep -c "kernel BUG"`
nr_error=`dmesg | grep -c "error"`
nr_null=`dmesg | grep -c "kernel NULL pointer dereference"`
nr_warning=`dmesg | grep -c "^WARNING"`
nr_lockdep=`dmesg | grep -c "possible recursive locking detected"`

#check if some kind of kernel bug happened
check_kernel_bug()
{
	new_bug=`dmesg | grep -c "kernel BUG"`
	new_error=`dmesg | grep -c "error"`
	new_null=`dmesg | grep -c "kernel NULL pointer dereference"`
	new_warning=`dmesg | grep -c "^WARNING"`
	new_lockdep=`dmesg | grep -c "possible recursive locking detected"`

	# no kernel bug is detected
	if [ $new_bug -eq $nr_bug -a $new_error -eq $nr_error -a \
	     $new_null -eq $nr_null -a $new_warning -eq $nr_warning -a \
	     $new_lockdep -eq $nr_lockdep ]; then
		return 0
	fi

	nr_bug=$new_bug
	nr_error=$new_error
	nr_null=$new_null
	nr_warning=$new_warning
	nr_lockdep=$new_lockdep
	return 1
}

RUN_TIME=$((30 * $TIME_FACTOR))

SEQ_DIR=$TEST_DIR/$seq
mkdir -p $SEQ_DIR
for n in {1..4096}; do
	touch $SEQ_DIR/$n
done

_test_read()
{
	src/t_readdir_1 $SEQ_DIR &
	sleep $RUN_TIME
	$KILLALL_PROG t_readdir_1
	check_kernel_bug
	if [ $? -ne 0 ]; then
		_fatal "kernel bug detected, check dmesg for more infomation."
	fi
}

_test_lseek()
{
	src/t_readdir_2 $SEQ_DIR &
	sleep $RUN_TIME
	$KILLALL_PROG t_readdir_2
	check_kernel_bug
	if [ $? -ne 0 ]; then
		_fatal "kernel bug detected, check dmesg for more infomation."
	fi
}

_test_read
_test_lseek

# success, all done
echo "*** done"
status=0
exit
