selftests/zram: Adding zram tests

zram: Compressed RAM based block devices
----------------------------------------
The zram module creates RAM based block devices named /dev/zram<id>
(<id> = 0, 1, ...). Pages written to these disks are compressed and stored
in memory itself. These disks allow very fast I/O and compression provides
good amounts of memory savings. Some of the usecases include /tmp storage,
use as swap disks, various caches under /var and maybe many more :)

Statistics for individual zram devices are exported through sysfs nodes at
/sys/block/zram<id>/

This patch is to validate the zram functionality. Test interacts with block
device /dev/zram<id> and sysfs nodes /sys/block/zram<id>/

zram.sh: sanity check of CONFIG_ZRAM and to run zram01 and zram02 tests
zram01.sh: creates general purpose ram disks with different filesystems
zram02.sh: creates block device for swap
zram_lib.sh: create library with initialization/cleanup functions
README: ZRAM introduction and Kconfig required.
Makefile: To run zram tests

zram test output
-----------------
./zram.sh
--------------------
running zram tests
--------------------
/dev/zram0 device file found: OK
set max_comp_streams to zram device(s)
/sys/block/zram0/max_comp_streams = '2' (1/1)
zram max streams: OK
test that we can set compression algorithm
supported algs: [lzo] lz4
/sys/block/zram0/comp_algorithm = 'lzo' (1/1)
zram set compression algorithm: OK
set disk size to zram device(s)
/sys/block/zram0/disksize = '2097152' (1/1)
zram set disksizes: OK
set memory limit to zram device(s)
/sys/block/zram0/mem_limit = '2M' (1/1)
zram set memory limit: OK
make ext4 filesystem on /dev/zram0
zram mkfs.ext4: OK
mount /dev/zram0
zram mount of zram device(s): OK
fill zram0...
zram0 can be filled with '1932' KB
zram used 3M, zram disk sizes 2097152M
zram compression ratio: 699050.66:1: OK
zram cleanup
zram01 : [PASS]

/dev/zram0 device file found: OK
set max_comp_streams to zram device(s)
/sys/block/zram0/max_comp_streams = '2' (1/1)
zram max streams: OK
set disk size to zram device(s)
/sys/block/zram0/disksize = '1048576' (1/1)
zram set disksizes: OK
set memory limit to zram device(s)
/sys/block/zram0/mem_limit = '1M' (1/1)
zram set memory limit: OK
make swap with zram device(s)
done with /dev/zram0
zram making zram mkswap and swapon: OK
zram swapoff: OK
zram cleanup
zram02 : [PASS]

CC: Shuah Khan <shuahkh@osg.samsung.com>
CC: Tyler Baker <tyler.baker@linaro.org>
CC: Milosz Wasilewski <milosz.wasilewski@linaro.org>
CC: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Reviewed-By: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>

tools/testing/selftests/Makefile

@@ -22,6 +22,7 @@ endif
 TARGETS += user
 TARGETS += vm
 TARGETS += x86
+TARGETS += zram
 #Please keep the TARGETS list alphabetically sorted
 # Run "make quicktest=1 run_tests" or
 # "make quicktest=1 kselftest from top level Makefile

tools/testing/selftests/zram/Makefile

+all:
+
+TEST_PROGS := zram.sh
+TEST_FILES := zram01.sh zram02.sh zram_lib.sh
+
+include ../lib.mk
+
+run_tests:
+	@/bin/bash ./zram.sh
+
+clean:
+	$(RM) err.log

tools/testing/selftests/zram/README

+zram: Compressed RAM based block devices
+----------------------------------------
+* Introduction
+
+The zram module creates RAM based block devices named /dev/zram<id>
+(<id> = 0, 1, ...). Pages written to these disks are compressed and stored
+in memory itself. These disks allow very fast I/O and compression provides
+good amounts of memory savings. Some of the usecases include /tmp storage,
+use as swap disks, various caches under /var and maybe many more :)
+
+Statistics for individual zram devices are exported through sysfs nodes at
+/sys/block/zram<id>/
+
+Kconfig required:
+CONFIG_ZRAM=y
+CONFIG_ZRAM_LZ4_COMPRESS=y
+CONFIG_ZPOOL=y
+CONFIG_ZSMALLOC=y
+
+ZRAM Testcases
+--------------
+zram_lib.sh: create library with initialization/cleanup functions
+zram.sh: For sanity check of CONFIG_ZRAM and to run zram01 and zram02
+
+Two functional tests: zram01 and zram02:
+zram01.sh: creates general purpose ram disks with ext4 filesystems
+zram02.sh: creates block device for swap
+
+Commands required for testing:
+ - bc
+ - dd
+ - free
+ - awk
+ - mkswap
+ - swapon
+ - swapoff
+ - mkfs/ mkfs.ext4
+
+For more information please refer:
+kernel-source-tree/Documentation/blockdev/zram.txt

tools/testing/selftests/zram/zram.sh

+#!/bin/bash
+TCID="zram.sh"
+
+run_zram () {
+echo "--------------------"
+echo "running zram tests"
+echo "--------------------"
+./zram01.sh
+echo ""
+./zram02.sh
+}
+
+# check zram module exists
+MODULE_PATH=/lib/modules/`uname -r`/kernel/drivers/block/zram/zram.ko
+if [ -f $MODULE_PATH ]; then
+	run_zram
+elif [ -b /dev/zram0 ]; then
+	run_zram
+else
+	echo "$TCID : No zram.ko module or /dev/zram0 device file not found"
+	echo "$TCID : CONFIG_ZRAM is not set"
+	exit 1
+fi

tools/testing/selftests/zram/zram01.sh

+#!/bin/bash
+# Copyright (c) 2015 Oracle and/or its affiliates. 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; either version 2 of
+# the License, or (at your option) any later version.
+#
+# 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.
+#
+# Test creates several zram devices with different filesystems on them.
+# It fills each device with zeros and checks that compression works.
+#
+# Author: Alexey Kodanev <alexey.kodanev@oracle.com>
+# Modified: Naresh Kamboju <naresh.kamboju@linaro.org>
+
+TCID="zram01"
+ERR_CODE=0
+
+. ./zram_lib.sh
+
+# Test will create the following number of zram devices:
+dev_num=1
+# This is a list of parameters for zram devices.
+# Number of items must be equal to 'dev_num' parameter.
+zram_max_streams="2"
+
+# The zram sysfs node 'disksize' value can be either in bytes,
+# or you can use mem suffixes. But in some old kernels, mem
+# suffixes are not supported, for example, in RHEL6.6GA's kernel
+# layer, it uses strict_strtoull() to parse disksize which does
+# not support mem suffixes, in some newer kernels, they use
+# memparse() which supports mem suffixes. So here we just use
+# bytes to make sure everything works correctly.
+zram_sizes="2097152" # 2MB
+zram_mem_limits="2M"
+zram_filesystems="ext4"
+zram_algs="lzo"
+
+zram_fill_fs()
+{
+	local mem_free0=$(free -m | awk 'NR==2 {print $4}')
+
+	for i in $(seq 0 $(($dev_num - 1))); do
+		echo "fill zram$i..."
+		local b=0
+		while [ true ]; do
+			dd conv=notrunc if=/dev/zero of=zram${i}/file \
+				oflag=append count=1 bs=1024 status=none \
+				> /dev/null 2>&1 || break
+			b=$(($b + 1))
+		done
+		echo "zram$i can be filled with '$b' KB"
+	done
+
+	local mem_free1=$(free -m | awk 'NR==2 {print $4}')
+	local used_mem=$(($mem_free0 - $mem_free1))
+
+	local total_size=0
+	for sm in $zram_sizes; do
+		local s=$(echo $sm | sed 's/M//')
+		total_size=$(($total_size + $s))
+	done
+
+	echo "zram used ${used_mem}M, zram disk sizes ${total_size}M"
+
+	local v=$((100 * $total_size / $used_mem))
+
+	if [ "$v" -lt 100 ]; then
+		echo "FAIL compression ratio: 0.$v:1"
+		ERR_CODE=-1
+		zram_cleanup
+		return
+	fi
+
+	echo "zram compression ratio: $(echo "scale=2; $v / 100 " | bc):1: OK"
+}
+
+zram_load
+zram_max_streams
+zram_compress_alg
+zram_set_disksizes
+zram_set_memlimit
+zram_makefs
+zram_mount
+
+zram_fill_fs
+zram_cleanup
+zram_unload
+
+if [ $ERR_CODE -ne 0 ]; then
+	echo "$TCID : [FAIL]"
+else
+	echo "$TCID : [PASS]"
+fi

tools/testing/selftests/zram/zram02.sh

+#!/bin/bash
+# Copyright (c) 2015 Oracle and/or its affiliates. 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; either version 2 of
+# the License, or (at your option) any later version.
+#
+# 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.
+#
+# Test checks that we can create swap zram device.
+#
+# Author: Alexey Kodanev <alexey.kodanev@oracle.com>
+# Modified: Naresh Kamboju <naresh.kamboju@linaro.org>
+
+TCID="zram02"
+ERR_CODE=0
+
+. ./zram_lib.sh
+
+# Test will create the following number of zram devices:
+dev_num=1
+# This is a list of parameters for zram devices.
+# Number of items must be equal to 'dev_num' parameter.
+zram_max_streams="2"
+
+# The zram sysfs node 'disksize' value can be either in bytes,
+# or you can use mem suffixes. But in some old kernels, mem
+# suffixes are not supported, for example, in RHEL6.6GA's kernel
+# layer, it uses strict_strtoull() to parse disksize which does
+# not support mem suffixes, in some newer kernels, they use
+# memparse() which supports mem suffixes. So here we just use
+# bytes to make sure everything works correctly.
+zram_sizes="1048576" # 1M
+zram_mem_limits="1M"
+
+zram_load
+zram_max_streams
+zram_set_disksizes
+zram_set_memlimit
+zram_makeswap
+zram_swapoff
+zram_cleanup
+zram_unload
+
+if [ $ERR_CODE -ne 0 ]; then
+	echo "$TCID : [FAIL]"
+else
+	echo "$TCID : [PASS]"
+fi

tools/testing/selftests/zram/zram_lib.sh

+#!/bin/sh
+# Copyright (c) 2015 Oracle and/or its affiliates. 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; either version 2 of
+# the License, or (at your option) any later version.
+#
+# 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.
+#
+# Author: Alexey Kodanev <alexey.kodanev@oracle.com>
+# Modified: Naresh Kamboju <naresh.kamboju@linaro.org>
+
+MODULE=0
+dev_makeswap=-1
+dev_mounted=-1
+
+trap INT
+
+zram_cleanup()
+{
+	echo "zram cleanup"
+	local i=
+	for i in $(seq 0 $dev_makeswap); do
+		swapoff /dev/zram$i
+	done
+
+	for i in $(seq 0 $dev_mounted); do
+		umount /dev/zram$i
+	done
+
+	for i in $(seq 0 $(($dev_num - 1))); do
+		echo 1 > /sys/block/zram${i}/reset
+		rm -rf zram$i
+	done
+
+}
+
+zram_unload()
+{
+	if [ $MODULE -ne 0 ] ; then
+		echo "zram rmmod zram"
+		rmmod zram > /dev/null 2>&1
+	fi
+}
+
+zram_load()
+{
+	# check zram module exists
+	MODULE_PATH=/lib/modules/`uname -r`/kernel/drivers/block/zram/zram.ko
+	if [ -f $MODULE_PATH ]; then
+		MODULE=1
+		echo "create '$dev_num' zram device(s)"
+		modprobe zram num_devices=$dev_num
+		if [ $? -ne 0 ]; then
+			echo "failed to insert zram module"
+			exit 1
+		fi
+
+		dev_num_created=$(ls /dev/zram* | wc -w)
+
+		if [ "$dev_num_created" -ne "$dev_num" ]; then
+			echo "unexpected num of devices: $dev_num_created"
+			ERR_CODE=-1
+		else
+			echo "zram load module successful"
+		fi
+	elif [ -b /dev/zram0 ]; then
+		echo "/dev/zram0 device file found: OK"
+	else
+		echo "ERROR: No zram.ko module or no /dev/zram0 device found"
+		echo "$TCID : CONFIG_ZRAM is not set"
+		exit 1
+	fi
+}
+
+zram_max_streams()
+{
+	echo "set max_comp_streams to zram device(s)"
+
+	local i=0
+	for max_s in $zram_max_streams; do
+		local sys_path="/sys/block/zram${i}/max_comp_streams"
+		echo $max_s > $sys_path || \
+			echo "FAIL failed to set '$max_s' to $sys_path"
+		sleep 1
+		local max_streams=$(cat $sys_path)
+
+		[ "$max_s" -ne "$max_streams" ] && \
+			echo "FAIL can't set max_streams '$max_s', get $max_stream"
+
+		i=$(($i + 1))
+		echo "$sys_path = '$max_streams' ($i/$dev_num)"
+	done
+
+	echo "zram max streams: OK"
+}
+
+zram_compress_alg()
+{
+	echo "test that we can set compression algorithm"
+
+	local algs=$(cat /sys/block/zram0/comp_algorithm)
+	echo "supported algs: $algs"
+	local i=0
+	for alg in $zram_algs; do
+		local sys_path="/sys/block/zram${i}/comp_algorithm"
+		echo "$alg" >	$sys_path || \
+			echo "FAIL can't set '$alg' to $sys_path"
+		i=$(($i + 1))
+		echo "$sys_path = '$alg' ($i/$dev_num)"
+	done
+
+	echo "zram set compression algorithm: OK"
+}
+
+zram_set_disksizes()
+{
+	echo "set disk size to zram device(s)"
+	local i=0
+	for ds in $zram_sizes; do
+		local sys_path="/sys/block/zram${i}/disksize"
+		echo "$ds" >	$sys_path || \
+			echo "FAIL can't set '$ds' to $sys_path"
+
+		i=$(($i + 1))
+		echo "$sys_path = '$ds' ($i/$dev_num)"
+	done
+
+	echo "zram set disksizes: OK"
+}
+
+zram_set_memlimit()
+{
+	echo "set memory limit to zram device(s)"
+
+	local i=0
+	for ds in $zram_mem_limits; do
+		local sys_path="/sys/block/zram${i}/mem_limit"
+		echo "$ds" >	$sys_path || \
+			echo "FAIL can't set '$ds' to $sys_path"
+
+		i=$(($i + 1))
+		echo "$sys_path = '$ds' ($i/$dev_num)"
+	done
+
+	echo "zram set memory limit: OK"
+}
+
+zram_makeswap()
+{
+	echo "make swap with zram device(s)"
+	local i=0
+	for i in $(seq 0 $(($dev_num - 1))); do
+		mkswap /dev/zram$i > err.log 2>&1
+		if [ $? -ne 0 ]; then
+			cat err.log
+			echo "FAIL mkswap /dev/zram$1 failed"
+		fi
+
+		swapon /dev/zram$i > err.log 2>&1
+		if [ $? -ne 0 ]; then
+			cat err.log
+			echo "FAIL swapon /dev/zram$1 failed"
+		fi
+
+		echo "done with /dev/zram$i"
+		dev_makeswap=$i
+	done
+
+	echo "zram making zram mkswap and swapon: OK"
+}
+
+zram_swapoff()
+{
+	local i=
+	for i in $(seq 0 $dev_makeswap); do
+		swapoff /dev/zram$i > err.log 2>&1
+		if [ $? -ne 0 ]; then
+			cat err.log
+			echo "FAIL swapoff /dev/zram$i failed"
+		fi
+	done
+	dev_makeswap=-1
+
+	echo "zram swapoff: OK"
+}
+
+zram_makefs()
+{
+	local i=0
+	for fs in $zram_filesystems; do
+		# if requested fs not supported default it to ext2
+		which mkfs.$fs > /dev/null 2>&1 || fs=ext2
+
+		echo "make $fs filesystem on /dev/zram$i"
+		mkfs.$fs /dev/zram$i > err.log 2>&1
+		if [ $? -ne 0 ]; then
+			cat err.log
+			echo "FAIL failed to make $fs on /dev/zram$i"
+		fi
+		i=$(($i + 1))
+		echo "zram mkfs.$fs: OK"
+	done
+}
+
+zram_mount()
+{
+	local i=0
+	for i in $(seq 0 $(($dev_num - 1))); do
+		echo "mount /dev/zram$i"
+		mkdir zram$i
+		mount /dev/zram$i zram$i > /dev/null || \
+			echo "FAIL mount /dev/zram$i failed"
+		dev_mounted=$i
+	done
+
+	echo "zram mount of zram device(s): OK"
+}