[LTP] [PATCH v3 2/3] zram/zram_lib.sh: Skip test if zram module can not be removed

[Yang Xu]

If zram-generator package is installed and works, then we can not
remove zram module because zram swap is being used. We can also use zramstart
command or similar shell script(use zramctl,mkswap,swapon) to do this.

Since zram01.sh and zram02.sh needs to rmmod and modprobe, they can't work well
if zram module can't be removed. So skip it.

Fixes: #888
Signed-off-by: Yang Xu <xuyang2018.jy@fujitsu.com>
---
 testcases/kernel/device-drivers/zram/zram_lib.sh | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/testcases/kernel/device-drivers/zram/zram_lib.sh b/testcases/kernel/device-drivers/zram/zram_lib.sh
index fe9c915c3..26f19ec02 100755
--- a/testcases/kernel/device-drivers/zram/zram_lib.sh
+++ b/testcases/kernel/device-drivers/zram/zram_lib.sh
@@ -5,6 +5,7 @@
 
 dev_makeswap=-1
 dev_mounted=-1
+dev_zram_load=-1
 
 TST_NEEDS_TMPDIR=1
 TST_NEEDS_ROOT=1
@@ -17,6 +18,10 @@ zram_cleanup()
 {
 	local i
 
+	if [ $dev_zram_load -le 0 ]; then
+		return
+	fi
+
 	for i in $(seq 0 $dev_makeswap); do
 		swapoff /dev/zram$i
 	done
@@ -47,6 +52,10 @@ zram_load()
 		tst_brk TBROK "dev_num must be > 0"
 	fi
 
+	if grep -q '^zram' /proc/modules; then
+		 rmmod zram > /dev/null 2>&1 || tst_brk TCONF "zram module is being used"
+	fi
+
 	tst_set_timeout $((dev_num*450))
 
 	tst_res TINFO "create '$dev_num' zram device(s)"
@@ -54,10 +63,12 @@ zram_load()
 	modprobe zram num_devices=$dev_num || \
 		tst_brk TBROK "failed to insert zram module"
 
+	dev_zram_load=1
 	dev_num_created=$(ls /dev/zram* | wc -w)
 
 	if [ "$dev_num_created" -ne "$dev_num" ]; then
-		tst_brk TFAIL "unexpected num of devices: $dev_num_created"
+		tst_brk TFAIL "expected num of devices $dev_num, but created"\
+				"$dev_num_created"
 	fi
 
 	tst_res TPASS "all zram devices successfully created"
-- 
2.23.0