LU-13160 tests: fix sanity-hsm monitor setup

On RHEL8, even we are using pdsh -R ssh,
the ssh still waits for the remote cat process
to finish.
Use the subshell to avoid the time out.

Change-Id: Id5b8d492b5ce9a235da73448ade475ade145bbed
Test-Parameters: trivial clientdistro=el8.1 testlist=sanity-hsm
Signed-off-by: Li Dongyang <dongyangli@ddn.com>
Reviewed-on: https://review.whamcloud.com/37595
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: James Nunez <jnunez@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/tests/sanity-hsm.sh b/lustre/tests/sanity-hsm.sh
index 0d9292c..e1a1368 100755 (executable)
--- a/lustre/tests/sanity-hsm.sh
+++ b/lustre/tests/sanity-hsm.sh
@@ -220,24 +220,17 @@ copytool_monitor_setup() {
        cmd="cat $test_dir/fifo > $test_dir/events &"
        cmd+=" echo \\\$! > $test_dir/monitor_pid"
 
-       if [[ $PDSH == *Rmrsh* ]]; then
-               # This is required for pdsh -Rmrsh and its handling of remote
-               # shells.
-               # Regular ssh and pdsh -Rssh work fine without this
-               # backgrounded subshell nonsense.
-               (do_node $agent "$cmd") &
-               export HSMTOOL_MONITOR_PDSH=$!
-
-               # Slightly racy, but just making a best-effort to catch obvious
-               # problems.
-               sleep 1
-               ps -p $HSMTOOL_MONITOR_PDSH > /dev/null ||
-                       error "Failed to start copytool monitor on $agent"
-       else
-               do_node $agent "$cmd"
-               if [ $? != 0 ]; then
-                       error "Failed to start copytool monitor on $agent"
-               fi
+       # This background subshell nonsense is required when pdsh/ssh decides
+       # to wait for the cat process to exit on the remote client
+       (do_node $agent "$cmd") &
+       export HSMTOOL_MONITOR_PDSH=$!
+
+       # Slightly racy, but just making a best-effort to catch obvious
+       # problems.
+       sleep 1
+       do_node $agent "stat $HSMTOOL_MONITOR_DIR/monitor_pid 2>&1 > /dev/null"
+       if [ $? != 0 ]; then
+               error "Failed to start copytool monitor on $agent"
        fi
 }