From 4ca457b065c6d95d9b6b2ed776f14e7e33257b94 Mon Sep 17 00:00:00 2001
From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Wed, 19 Jun 2019 10:39:28 -0700
Subject: [PATCH] ZTS: Fix mmp_interval failure

The mmp_interval test case was failing on Fedora 30 due to the built-in
'echo' command terminating the script when it was unable to write to
the sysfs module parameter.  This change in behavior was observed with
ksh-2020.0.0-alpha1.  Resolve the issue by using the external cat
command which fails gracefully as expected.

Additionally, remove some incorrect quotes around the $? return values.

Reviewed-by: Giuseppe Di Natale <guss80@gmail.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Olaf Faaland <faaland1@llnl.gov>
Reviewed-by: Richard Elling <Richard.Elling@RichardElling.com>
Reviewed-by: George Melikov <mail@gmelikov.ru>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #8906
---
 tests/zfs-tests/include/libtest.shlib | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/zfs-tests/include/libtest.shlib b/tests/zfs-tests/include/libtest.shlib
index 9c3c20fd9517..7078eb30b1c6 100644
--- a/tests/zfs-tests/include/libtest.shlib
+++ b/tests/zfs-tests/include/libtest.shlib
@@ -3495,13 +3495,13 @@ function set_tunable_impl
 	Linux)
 		typeset zfs_tunables="/sys/module/$module/parameters"
 		[[ -w "$zfs_tunables/$tunable" ]] || return 1
-		echo -n "$value" > "$zfs_tunables/$tunable"
-		return "$?"
+		cat >"$zfs_tunables/$tunable" <<<"$value"
+		return $?
 		;;
 	SunOS)
 		[[ "$module" -eq "zfs" ]] || return 1
 		echo "${tunable}/${mdb_cmd}0t${value}" | mdb -kw
-		return "$?"
+		return $?
 		;;
 	esac
 }
@@ -3528,7 +3528,7 @@ function get_tunable_impl
 		typeset zfs_tunables="/sys/module/$module/parameters"
 		[[ -f "$zfs_tunables/$tunable" ]] || return 1
 		cat $zfs_tunables/$tunable
-		return "$?"
+		return $?
 		;;
 	SunOS)
 		[[ "$module" -eq "zfs" ]] || return 1