#!/usr/bin/bash -p
#
# CDDL HEADER START
#
# The contents of this file are subject to the terms of the
# Common Development and Distribution License (the "License").
# You may not use this file except in compliance with the License.
#
# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
# or http://www.opensolaris.org/os/licensing.
# See the License for the specific language governing permissions
# and limitations under the License.
#
# When distributing Covered Code, include this CDDL HEADER in each
# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
# If applicable, add the following below this CDDL HEADER, with the
# fields enclosed by brackets "[]" replaced with your own identifying
# information: Portions Copyright [yyyy] [name of copyright owner]
#
# CDDL HEADER END
#

#
# Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
# Use is subject to license terms.
#

#
# Copyright (c) 2013, 2016 by Delphix. All rights reserved.
#

. $STF_SUITE/include/libtest.shlib
. $STF_SUITE/tests/functional/reservation/reservation.shlib

#
# DESCRIPTION:
#
# In pool with a full filesystem and a regular volume with an implicit
# reservation, setting the reservation on the volume to 'none' should allow
# more data to be written to the filesystem.
#
#
# STRATEGY:
# 1) Create a regular non-sparse volume (which implicitly sets the reservation
#    property to a value equal to the volume size)
# 2) Create a filesystem at the same level
# 3) Fill up the filesystem
# 4) Set the reservation on the volume to 'none'
# 5) Verify can write more data to the filesystem
#

verify_runnable "global"

log_assert "Setting volume reservation to 'none' allows more data to be " \
    "written to top level filesystem"

function cleanup
{
	datasetexists $TESTPOOL/$TESTVOL && \
	log_must zfs destroy $TESTPOOL/$TESTVOL

	[[ -e $TESTDIR/$TESTFILE1 ]] && log_must rm -rf $TESTDIR/$TESTFILE1
	[[ -e $TESTDIR/$TESTFILE2 ]] && log_must rm -rf $TESTDIR/$TESTFILE2
}
log_onexit cleanup

space_avail=$(largest_volsize_from_pool $TESTPOOL)

#
# To make sure this test doesn't take too long to execute on
# large pools, we calculate a volume size which when applied
# to the volume will ensure we have RESV_FREE_SPACE
# left free in the pool which we can quickly fill.
#
((resv_size_set = space_avail - RESV_FREE_SPACE))
resv_size_set=$(floor_volsize $resv_size_set)

log_must zfs create -V $resv_size_set $TESTPOOL/$TESTVOL

space_avail_still=`get_prop available $TESTPOOL`

fill_size=$((space_avail_still + $RESV_TOLERANCE))
write_count=$((fill_size / BLOCK_SIZE))

# Now fill up the filesystem (which doesn't have a reservation set
# and thus will use up whatever free space is left in the pool).
file_write -o create -f $TESTDIR/$TESTFILE1 -b $BLOCK_SIZE -c $write_count -d 0
ret=$?
if (($ret != $ENOSPC)); then
	log_fail "Did not get ENOSPC as expected (got $ret)."
fi

log_must zfs set refreservation=none $TESTPOOL/$TESTVOL

log_must file_write -o create -f $TESTDIR/$TESTFILE2 -b pagesize \
    -c 1000 -d 0

log_pass "Setting top level volume reservation to 'none' allows more " \
    "data to be written to the top level filesystem"