[PATCH 5.10 027/121] selftests/zram: Adapt the situation that /dev/zram0 is being used

Greg Kroah-Hartman
2022-02-21T09:13:08Z

From: Yang Xu <xuyang2018.jy@fujitsu.com>

[ Upstream commit 01dabed20573804750af5c7bf8d1598a6bf7bf6e ]

If zram-generator package is installed and works, then we can not remove
zram module because zram swap is being used. This case needs a clean zram
environment, change this test by using hot_add/hot_remove interface. So
even zram device is being used, we still can add zram device and remove
them in cleanup.

The two interface was introduced since kernel commit 6566d1a32bf7("zram:
add dynamic device add/remove functionality") in v4.2-rc1. If kernel
supports these two interface, we use hot_add/hot_remove to slove this
problem, if not, just check whether zram is being used or built in, then
skip it on old kernel.

Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/testing/selftests/zram/zram.sh | 15 +---
tools/testing/selftests/zram/zram01.sh | 3 +-
tools/testing/selftests/zram/zram02.sh | 1 -
tools/testing/selftests/zram/zram_lib.sh | 110 +++++++++++++----------
4 files changed, 66 insertions(+), 63 deletions(-)

diff --git a/tools/testing/selftests/zram/zram.sh b/tools/testing/selftests/zram/zram.sh
index 232e958ec4547..b0b91d9b0dc21 100755
--- a/tools/testing/selftests/zram/zram.sh
+++ b/tools/testing/selftests/zram/zram.sh
@@ -2,9 +2,6 @@
# SPDX-License-Identifier: GPL-2.0
TCID="zram.sh"

-# Kselftest framework requirement - SKIP code is 4.
-ksft_skip=4
-
. ./zram_lib.sh

run_zram () {
@@ -18,14 +15,4 @@ echo ""

check_prereqs

-# 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 $ksft_skip
-fi
+run_zram
diff --git a/tools/testing/selftests/zram/zram01.sh b/tools/testing/selftests/zram/zram01.sh
index e9e9eb777e2c7..8f4affe34f3e4 100755
--- a/tools/testing/selftests/zram/zram01.sh
+++ b/tools/testing/selftests/zram/zram01.sh
@@ -33,7 +33,7 @@ zram_algs="lzo"

zram_fill_fs()
{
- for i in $(seq 0 $(($dev_num - 1))); do
+ for i in $(seq $dev_start $dev_end); do
echo "fill zram$i..."
local b=0
while [ true ]; do
@@ -67,7 +67,6 @@ zram_mount

zram_fill_fs
zram_cleanup
-zram_unload

if [ $ERR_CODE -ne 0 ]; then
echo "$TCID : [FAIL]"
diff --git a/tools/testing/selftests/zram/zram02.sh b/tools/testing/selftests/zram/zram02.sh
index e83b404807c09..2418b0c4ed136 100755
--- a/tools/testing/selftests/zram/zram02.sh
+++ b/tools/testing/selftests/zram/zram02.sh
@@ -36,7 +36,6 @@ zram_set_memlimit
zram_makeswap
zram_swapoff
zram_cleanup
-zram_unload

if [ $ERR_CODE -ne 0 ]; then
echo "$TCID : [FAIL]"
diff --git a/tools/testing/selftests/zram/zram_lib.sh b/tools/testing/selftests/zram/zram_lib.sh
index f47fc0f27e99e..21ec1966de76c 100755
--- a/tools/testing/selftests/zram/zram_lib.sh
+++ b/tools/testing/selftests/zram/zram_lib.sh
@@ -5,10 +5,12 @@
# Author: Alexey Kodanev <alexey.kodanev@oracle.com>
# Modified: Naresh Kamboju <naresh.kamboju@linaro.org>

-MODULE=0
dev_makeswap=-1
dev_mounted=-1
-
+dev_start=0
+dev_end=-1
+module_load=-1
+sys_control=-1
# Kselftest framework requirement - SKIP code is 4.
ksft_skip=4
kernel_version=`uname -r | cut -d'.' -f1,2`
@@ -46,57 +48,72 @@ zram_cleanup()
{
echo "zram cleanup"
local i=
- for i in $(seq 0 $dev_makeswap); do
+ for i in $(seq $dev_start $dev_makeswap); do
swapoff /dev/zram$i
done

- for i in $(seq 0 $dev_mounted); do
+ for i in $(seq $dev_start $dev_mounted); do
umount /dev/zram$i
done

- for i in $(seq 0 $(($dev_num - 1))); do
+ for i in $(seq $dev_start $dev_end); do
echo 1 > /sys/block/zram${i}/reset
rm -rf zram$i
done

-}
+ if [ $sys_control -eq 1 ]; then
+ for i in $(seq $dev_start $dev_end); do
+ echo $i > /sys/class/zram-control/hot_remove
+ done
+ fi

-zram_unload()
-{
- if [ $MODULE -ne 0 ] ; then
- echo "zram rmmod zram"
+ if [ $module_load -eq 1 ]; then
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)
+ echo "create '$dev_num' zram device(s)"
+
+ # zram module loaded, new kernel
+ if [ -d "/sys/class/zram-control" ]; then
+ echo "zram modules already loaded, kernel supports" \
+ "zram-control interface"
+ dev_start=$(ls /dev/zram* | wc -w)
+ dev_end=$(($dev_start + $dev_num - 1))
+ sys_control=1
+
+ for i in $(seq $dev_start $dev_end); do
+ cat /sys/class/zram-control/hot_add > /dev/null
+ done
+
+ echo "all zram devices (/dev/zram$dev_start~$dev_end" \
+ "successfully created"
+ return 0
+ fi

- if [ "$dev_num_created" -ne "$dev_num" ]; then
- echo "unexpected num of devices: $dev_num_created"
- ERR_CODE=-1
+ # detect old kernel or built-in
+ modprobe zram num_devices=$dev_num
+ if [ ! -d "/sys/class/zram-control" ]; then
+ if grep -q '^zram' /proc/modules; then
+ rmmod zram > /dev/null 2>&1
+ if [ $? -ne 0 ]; then
+ echo "zram module is being used on old kernel" \
+ "without zram-control interface"
+ exit $ksft_skip
+ fi
else
- echo "zram load module successful"
+ echo "test needs CONFIG_ZRAM=m on old kernel without" \
+ "zram-control interface"
+ exit $ksft_skip
fi
- elif [ -b /dev/zram0 ]; then
- echo "/dev/zram0 device file found: OK"
- else
- echo "ERROR: No zram.ko module or no /dev/zram0 device found"
- echo "$TCID : CONFIG_ZRAM is not set"
- exit 1
+ modprobe zram num_devices=$dev_num
fi
+
+ module_load=1
+ dev_end=$(($dev_num - 1))
+ echo "all zram devices (/dev/zram0~$dev_end) successfully created"
}

zram_max_streams()
@@ -110,7 +127,7 @@ zram_max_streams()
return 0
fi

- local i=0
+ local i=$dev_start
for max_s in $zram_max_streams; do
local sys_path="/sys/block/zram${i}/max_comp_streams"
echo $max_s > $sys_path || \
@@ -122,7 +139,7 @@ zram_max_streams()
echo "FAIL can't set max_streams '$max_s', get $max_stream"

i=$(($i + 1))
- echo "$sys_path = '$max_streams' ($i/$dev_num)"
+ echo "$sys_path = '$max_streams'"
done

echo "zram max streams: OK"
@@ -132,15 +149,16 @@ zram_compress_alg()
{
echo "test that we can set compression algorithm"

- local algs=$(cat /sys/block/zram0/comp_algorithm)
+ local i=$dev_start
+ local algs=$(cat /sys/block/zram${i}/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/$dev_num)"
+ echo "$sys_path = '$alg'"
done

echo "zram set compression algorithm: OK"
@@ -149,14 +167,14 @@ zram_compress_alg()
zram_set_disksizes()
{
echo "set disk size to zram device(s)"
- local i=0
+ local i=$dev_start
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)"
+ echo "$sys_path = '$ds'"
done

echo "zram set disksizes: OK"
@@ -166,14 +184,14 @@ zram_set_memlimit()
{
echo "set memory limit to zram device(s)"

- local i=0
+ local i=$dev_start
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)"
+ echo "$sys_path = '$ds'"
done

echo "zram set memory limit: OK"
@@ -182,8 +200,8 @@ zram_set_memlimit()
zram_makeswap()
{
echo "make swap with zram device(s)"
- local i=0
- for i in $(seq 0 $(($dev_num - 1))); do
+ local i=$dev_start
+ for i in $(seq $dev_start $dev_end); do
mkswap /dev/zram$i > err.log 2>&1
if [ $? -ne 0 ]; then
cat err.log
@@ -206,7 +224,7 @@ zram_makeswap()
zram_swapoff()
{
local i=
- for i in $(seq 0 $dev_makeswap); do
+ for i in $(seq $dev_start $dev_end); do
swapoff /dev/zram$i > err.log 2>&1
if [ $? -ne 0 ]; then
cat err.log
@@ -220,7 +238,7 @@ zram_swapoff()

zram_makefs()
{
- local i=0
+ local i=$dev_start
for fs in $zram_filesystems; do
# if requested fs not supported default it to ext2
which mkfs.$fs > /dev/null 2>&1 || fs=ext2
@@ -239,7 +257,7 @@ zram_makefs()
zram_mount()
{
local i=0
- for i in $(seq 0 $(($dev_num - 1))); do
+ for i in $(seq $dev_start $dev_end); do
echo "mount /dev/zram$i"
mkdir zram$i
mount /dev/zram$i zram$i > /dev/null || \
--
2.34.1