#! /bin/bash
# FS QA Test No. 067
#
# Some random mount/umount corner case tests
#
# - mount at a nonexistent mount point
# - mount a free loop device
# - mount with a wrong fs type specified
# - umount an symlink to device which is not mounted
# - umount a path with too long name
# - lazy umount a symlink
#
#-----------------------------------------------------------------------
# Copyright (c) 2015 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
#-----------------------------------------------------------------------
#

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()
{
	cd /
	rm -f $tmp.*
}

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

# real QA test starts here

# Modify as appropriate.
_supported_fs generic
_supported_os Linux
_require_test_symlinks
_require_test
_require_scratch
_require_loop
_require_block_device $SCRATCH_DEV

rm -f $seqres.full

_scratch_mkfs >>$seqres.full 2>&1

# kernel should not hang nor oops when mounting fs to nonexistent mount point
mount_nonexistent_mnt()
{
	echo "# mount to nonexistent mount point" >>$seqres.full
	rm -rf $TEST_DIR/nosuchdir
	$MOUNT_PROG $SCRATCH_DEV $TEST_DIR/nosuchdir >>$seqres.full 2>&1
}

# fs driver should be able to handle mounting a free loop device gracefully
# xfs ever hung, "ec53d1d xfs: don't block on buffer read errors" fixed it
mount_free_loopdev()
{
	echo "# mount a free loop device" >>$seqres.full
	loopdev=`losetup -f`
	$MOUNT_PROG -t $FSTYP $loopdev $SCRATCH_MNT >>$seqres.full 2>&1
}

# mount with wrong fs type specified.
# This should fail gracefully, no hang no oops are expected
mount_wrong_fstype()
{
	local fs=ext4
	if [ "$FSTYP" == "ext4" ]; then
		fs=xfs
	fi
	echo "# mount with wrong fs type" >>$seqres.full
	$MOUNT_PROG -t $fs $SCRATCH_DEV $SCRATCH_MNT >>$seqres.full 2>&1
}

# umount a symlink to device, which is not mounted.
# This should fail gracefully, no hang no oops are expected
umount_symlink_device()
{
	local symlink=$TEST_DIR/$seq.scratch_dev_symlink
	rm -f $symlink
	echo "# umount symlink to device, which is not mounted" >>$seqres.full
	ln -s $SCRATCH_DEV $symlink
	$UMOUNT_PROG $symlink >>$seqres.full 2>&1
}

# umount a path name that is 256 bytes long, this should fail gracefully,
# and the following umount should not hang nor oops
umount_toolong_name()
{
	local longname=$SCRATCH_MNT/`$PERL_PROG -e 'print "a"x256;'`

	_scratch_mount 2>&1 | tee -a $seqres.full

	echo "# umount a too-long name" >>$seqres.full
	$UMOUNT_PROG $longname >>$seqres.full 2>&1
	_scratch_unmount 2>&1 | tee -a $seqres.full
}

# lazy umount a symlink should not block following umount.
# This is the test case described in https://lkml.org/lkml/2014/7/21/98
lazy_umount_symlink()
{
	local symlink=$SCRATCH_MNT/$seq.testdir_symlink
	echo "# lazy umount a symlink" >>$seqres.full
	_scratch_mount 2>&1 | tee -a $seqres.full
	mkdir -p $SCRATCH_MNT/testdir
	rm -f $symlink
	ln -s $SCRATCH_MNT/testdir $symlink

	$UMOUNT_PROG -l $symlink >>$seqres.full 2>&1
	# _scratch_unmount should not be blocked
	_scratch_unmount 2>&1 | tee -a $seqres.full
}

echo "Silence is golden"

mount_nonexistent_mnt
mount_free_loopdev
mount_wrong_fstype

umount_symlink_device
umount_toolong_name
lazy_umount_symlink

status=0
exit