new file mode 100644
@@ -0,0 +1,88 @@
+devs="$dev0 $dev1 $dev2 $dev3"
+runtime=120
+pid=""
+action_pid=""
+
+set_up_injection()
+{
+ echo -1 > /sys/kernel/debug/fail_make_request/times
+ echo 1 > /sys/kernel/debug/fail_make_request/probability
+ echo 0 > /sys/kernel/debug/fail_make_request/verbose
+ echo 1 > /sys/block/${1##*/}/make-it-fail
+}
+
+clean_up_injection()
+{
+ echo 0 > /sys/block/${1##*/}/make-it-fail
+ echo 0 > /sys/kernel/debug/fail_make_request/times
+ echo 0 > /sys/kernel/debug/fail_make_request/probability
+ echo 2 > /sys/kernel/debug/fail_make_request/verbose
+}
+
+test_rdev()
+{
+ while true; do
+ mdadm -f $md0 $1 &> /dev/null
+ mdadm -r $md0 $1 &> /dev/null
+ mdadm --zero-superblock $1 &> /dev/null
+ mdadm -a $md0 $1 &> /dev/null
+ sleep $2
+ done
+}
+
+test_write_action()
+{
+ while true; do
+ echo frozen > /sys/block/md0/md/sync_action
+ echo idle > /sys/block/md0/md/sync_action
+ sleep 0.1
+ done
+}
+
+set_up_test()
+{
+ fio -h &> /dev/null || die "fio not found"
+
+ # create a simple raid10
+ mdadm -Cv -R -n 4 -l10 $md0 $devs || die "create raid10 failed"
+}
+
+clean_up_test()
+{
+ clean_up_injection $dev0
+ pkill -9 fio
+ kill -9 $pid
+ kill -9 $action_pid
+
+ sleep 1
+
+ if ps $action_pid | tail -1 | awk '{print $3}' | grep D; then
+ die "thread that is writing sysfs is stuck in D state, deadlock is triggered"
+ fi
+ mdadm -S $md0
+}
+
+cat /sys/kernel/debug/fail_make_request/times || die "fault injection is not enabled"
+
+trap 'clean_up_test' EXIT
+
+set_up_test || die "set up test failed"
+
+# backgroup io pressure
+fio -filename=$md0 -rw=randwrite -direct=1 -name=test -bs=4k -numjobs=16 -iodepth=16 &
+
+# trigger add/remove device by io failure
+set_up_injection $dev0
+test_rdev $dev0 2 &
+pid="$pid $!"
+
+# add/remove device directly
+test_rdev $dev3 10 &
+pid="$pid $!"
+
+test_write_action &
+action_pid="$!"
+
+sleep $runtime
+
+exit 0
new file mode 100644