test/shell/lvchange-cache-mode.sh

#!/bin/sh
# Copyright (C) 2016 Red Hat, Inc. All rights reserved.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions
# of the GNU General Public License v.2.
#
# 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

# Exercise changing of caching mode on both cache pool and cached LV.

SKIP_WITH_LVMLOCKD=1
SKIP_WITH_LVMPOLLD=1

. lib/inittest

aux have_cache 1 5 0 || skip

aux prepare_vg 2

lvcreate --type cache-pool -L18 -n cpool $vg "$dev1"
lvcreate -H -L14 -n $lv1 --cachemode writeback --cachesettings migration_threshold=204800 --cachepool $vg/cpool $vg "$dev2"

#cat "$DM_DEV_DIR/$vg/$lv1"  >/dev/null
#aux delay_dev "$dev2"  300 1000 $(get first_extent_sector "$dev2"):

#dmsetup status $vg-$lv1
#dmsetup table $vg-$lv1

for i in $(seq 1 10) ; do 
echo 3 >/proc/sys/vm/drop_caches
dd if=/dev/zero of="$DM_DEV_DIR/$vg/$lv1" bs=64K count=20 conv=fdatasync || true
echo 3 >/proc/sys/vm/drop_caches
dd if="$DM_DEV_DIR/$vg/$lv1" of=/dev/null bs=64K count=20 || true
done

lvs -o+cache_dirty_blocks,cache_read_hits,cache_read_misses,cache_write_hits,cache_write_misses $vg/$lv1

vgcfgbackup -f /tmp/ooo $vg


#
# Drop later, code loading dm tables directly without lvm
# RHBZ 1337588
#
#dmsetup table
#echo "STATUS before cleaner"
#dmsetup status
#dmsetup load --table "0 28672 cache 253:4 253:3 253:5 128 1 writethrough cleaner 0" $vg-$lv1
#dmsetup resume $vg-$lv1
#sleep 1
#dmsetup table
#echo "STATUS after cleaner 1sec"
#dmsetup status --noflush
#dmsetup suspend --noflush $vg-$lv1
#dmsetup resume $vg-$lv1

#dmsetup load --table "0 28672 cache 253:4 253:3 253:5 128 1 passthrough smq 2 migration_threshold 204800" $vg-$lv1
#dmsetup status $vg-$lv1
#dmsetup load --table "0 28672 cache 253:4 253:3 253:5 128 1 writethrough smq 2 migration_threshold 204800" $vg-$lv1
#dmsetup resume $vg-$lv1
#dmsetup status $vg-$lv1
#dmsetup table  $vg-$lv1
#dmsetup ls --tree
#exit

check lv_field $vg/$lv1 cache_mode "writeback"
lvchange --cachemode passthrough $vg/$lv1
check lv_field  $vg/$lv1 cache_mode "passthrough"
lvchange --cachemode writethrough $vg/$lv1
check lv_field  $vg/$lv1 cache_mode "writethrough"
lvchange --cachemode writeback $vg/$lv1
check lv_field  $vg/$lv1 cache_mode "writeback"

lvconvert --splitcache $vg/$lv1

lvs -a $vg

check lv_field $vg/cpool cache_mode "writeback"
lvchange --cachemode passthrough $vg/cpool
check lv_field  $vg/cpool cache_mode "passthrough"
lvchange --cachemode writethrough $vg/cpool
check lv_field  $vg/cpool cache_mode "writethrough"
lvchange --cachemode writeback $vg/cpool
check lv_field  $vg/cpool cache_mode "writeback"

lvs -a $vg

vgremove -f $vg