tests/ext4/033

#! /bin/bash
# FS QA Test 033
#
# Test s_inodes_count overflow for huge filesystems. This bug was fixed
# by commit "ext4: Forbid overflowing inode count when resizing".
#
#-----------------------------------------------------------------------
# Copyright (c) 2018 Jan Kara, SUSE.  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"

here=`pwd`
tmp=/tmp/$$
status=1	# failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15

_cleanup()
{
	umount $SCRATCH_MNT >/dev/null 2>&1
	_dmhugedisk_cleanup
	cd /
	rm -f $tmp.*
}

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

# remove previous $seqres.full before test
rm -f $seqres.full

# real QA test starts here
_supported_fs ext4
_supported_os Linux
_require_scratch_nocheck
_require_dmhugedisk
_require_dumpe2fs
_require_command "$RESIZE2FS_PROG" resize2fs

# Figure out whether device is large enough
devsize=$(blockdev --getsize64 $SCRATCH_DEV)
if [ $devsize -lt 4294967296 ]; then
	_notrun "Too small scratch device, need at least 4G"
fi

# Figure out block size
echo "Figure out block size"
_scratch_mkfs >/dev/null 2>&1
_scratch_mount >> $seqres.full
blksz="$(_get_block_size $SCRATCH_MNT)"
_scratch_unmount

inodes_per_group=$((blksz*8))
group_blocks=$((blksz*8))

# Number of groups to overflow s_inodes_count
limit_groups=$(((1<<32)/inodes_per_group))

# Create device huge enough so that overflowing inode count is possible.
# Set chunk size to 16 sectors. Group descriptors with META_BG feature
# are rather sparse and that leads to huge overallocation especially with
# 1k blocksize.
echo "Format huge device"
_dmhugedisk_init $(((limit_groups + 16)*group_blocks*(blksz/512))) 16

# Start with small fs
group_count=$((limit_groups - 16))
_mkfs_dev -N $((group_count*inodes_per_group)) -b $blksz \
	$DMHUGEDISK_DEV $((group_count*group_blocks))

_mount $DMHUGEDISK_DEV $SCRATCH_MNT

echo "Initial fs dump" >> $seqres.full
$DUMPE2FS_PROG -h $DMHUGEDISK_DEV >> $seqres.full 2>&1

# This should fail, s_inodes_count would just overflow!
echo "Resizing to inode limit + 1..."
$RESIZE2FS_PROG $DMHUGEDISK_DEV $((limit_groups*group_blocks)) >> $seqres.full 2>&1
if [ $? -eq 0 ]; then
	echo "Resizing succeeded but it should fail!"
	exit
fi

# This should succeed, we are maxing out inodes
echo "Resizing to max group count..."
$RESIZE2FS_PROG $DMHUGEDISK_DEV $(((limit_groups-1)*group_blocks)) >> $seqres.full 2>&1
if [ $? -ne 0 ]; then
	echo "Resizing failed!"
	exit
fi

echo "Fs dump after resize" >> $seqres.full
$DUMPE2FS_PROG -h $DMHUGEDISK_DEV >> $seqres.full 2>&1

# This should fail, s_inodes_count would overflow by quite a bit!
echo "Resizing to device size..."
$RESIZE2FS_PROG $DMHUGEDISK_DEV >> $seqres.full 2>&1
if [ $? -eq 0 ]; then
	echo "Resizing succeeded but it should fail!"
	exit
fi

# success, all done
status=0
exit