tests: simplify check_bg_procs_limit_num(), inline into setup

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12979

tests/zfs-tests/tests/functional/mv_files/mv_files_001_pos.ksh

@@ -53,7 +53,6 @@ verify_runnable "global"
 
 function cleanup
 {
-	PIDS=""
 	rm -f $OLDDIR/* >/dev/null 2>&1
 	rm -f $NEWDIR_IN_FS/* >/dev/null 2>&1
 }

tests/zfs-tests/tests/functional/mv_files/mv_files_002_pos.ksh

@@ -54,7 +54,6 @@ verify_runnable "global"
 
 function cleanup
 {
-	PIDS=""
 	rm -f $OLDDIR/* >/dev/null 2>&1
 	rm -f $NEWDIR_ACROSS_FS/* >/dev/null 2>&1
 }

tests/zfs-tests/tests/functional/mv_files/mv_files_common.kshlib

@@ -30,55 +30,6 @@
 
 . $STF_SUITE/tests/functional/mv_files/mv_files.cfg
 
-#
-# Determine whether this version of the ksh being
-# executed has a bug where the limit of background
-# processes of 25.
-#
-function check_bg_procs_limit_num
-{
-echo "#!/bin/ksh" > $TEST_BASE_DIR/exitsZero.ksh
-echo  "exit 0" >> $TEST_BASE_DIR/exitsZero.ksh
-chmod 777 $TEST_BASE_DIR/exitsZero.ksh
-
-cat <<EOF > $TEST_BASE_DIR/testbackgprocs.ksh
-#!/bin/ksh
-#
-# exitsZero.ksh is a one line script
-# that exit with status of "0"
-#
-
-PIDS=""
-typeset -i i=1
-while [ \$i -le 50 ]
-do
-	$TEST_BASE_DIR/exitsZero.ksh &
-        PIDS="\$PIDS \$!"
-        (( i = i + 1 ))
-done
-
-sleep 1
-
-for pid in \$PIDS
-do
-	wait \$pid
-        (( \$? == 127 )) && exit 1
-done
-exit 0
-EOF
-
-ksh $TEST_BASE_DIR/testbackgprocs.ksh
-if [[ $? -eq 1 ]]; then
-#
-# Current ksh being executed has a limit
-# of 25 background processes.
-#
-	return 1
-else
-        return 0
-fi
-}
-
 function init_setup
 {
 

tests/zfs-tests/tests/functional/mv_files/setup.ksh

@@ -34,13 +34,25 @@
 
 verify_runnable "global"
 
-check_bg_procs_limit_num
-if [[ $? -ne 0 ]]; then
-	log_note "ksh background process limit number is 25"
-	export GANGPIDS=25
-fi
+#
+# Determine whether this version of the ksh being
+# executed has a bug where the limit of background
+# processes of 25.
+#
+(
+	pids=
+	for _ in $(seq 50); do
+		: &
+		pids="$pids $!"
+	done
 
-export PIDS=""
+	for pid in $pids; do
+		wait $pid || exit
+	done
+) || {
+	log_note "ksh background process limit number is 25"
+	GANGPIDS=25
+}
 
 init_setup $DISK