From 1003d8141209fdbd50d02aec2cad4690aec48702 Mon Sep 17 00:00:00 2001
From: Guevenc Guelce <guvenc@linux.ibm.com>
Date: Wed, 8 Jul 2020 18:31:34 +0200
Subject: [PATCH] znetconf: introduce better ways to locate udevadm
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When udevadm is going to be used, try to locate it
in $PATH and if it fails, try to locate it in well-known
binary paths.

Signed-off-by: Guevenc Guelce <guvenc@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
---
 zconf/znetconf | 42 +++++++++++++++++++++++++++++++++---------
 1 file changed, 33 insertions(+), 9 deletions(-)

diff --git a/zconf/znetconf b/zconf/znetconf
index ba8dec4..497e97f 100755
--- a/zconf/znetconf
+++ b/zconf/znetconf
@@ -63,14 +63,8 @@ CMD=$(basename $0)
 LSZNET=/lib/s390-tools/lsznet.raw
 LSZNET_ARGS=-a
 LSZNET_CALL="$LSZNET $LSZNET_ARGS"
-UDEVSETTLE=/sbin/udevadm
-if [ ! -e $UDEVSETTLE ]
-then
-	UDEVSETTLE=/sbin/udevsettle
-	UDEVSETTLE_CALL="$UDEVSETTLE --timeout=10"
-else
-	UDEVSETTLE_CALL="$UDEVSETTLE settle --timeout=10"
-fi
+UDEVSETTLE=udevadm
+UDEVSETTLE_CALL="$UDEVSETTLE settle --timeout=10"
 SYSFSDIR=$(cat /proc/mounts|awk '$3=="sysfs"{print $2; exit}')
 CCWGROUPBUS_DIR=$SYSFSDIR/bus/ccwgroup
 CCWDEV_DIR=$SYSFSDIR/bus/ccw/devices
@@ -261,6 +255,35 @@ function lookup_lan_layer()
 
 #==============================================================================
 
+function prepare_udevsettle_cmd()
+{
+	# is the command available in $PATH
+	if ! [ -x "$(command -v $UDEVSETTLE)" ]
+	then
+		# check the well known locations.
+		if [ -e "/sbin/udevadm" ]
+		then
+			UDEVSETTLE=/sbin/udevadm
+			UDEVSETTLE_CALL="$UDEVSETTLE settle --timeout=10"
+		elif [ -e "/usr/bin/udevadm" ]
+		then
+			UDEVSETTLE=/usr/bin/udevadm
+			UDEVSETTLE_CALL="$UDEVSETTLE settle --timeout=10"
+		elif [ -e "/sbin/udevsettle" ]
+		then
+			# Fallback to udevsettle
+			UDEVSETTLE=/sbin/udevsettle
+			UDEVSETTLE_CALL="$UDEVSETTLE --timeout=10"
+		else
+			UDEVSETTLE=""
+			UDEVSETTLE_CALL=""
+			echo "Failed to find any candidate for udevsettle"
+		fi
+	fi
+}
+
+#==============================================================================
+
 function lookup_type_and_lan_or_vswitch_name()
 {
 	local DEVNO="$1"
@@ -506,8 +529,9 @@ function wait_for_net_device()
 	local CMD_FINDNETLINK="find $CCWGROUPBUS_DEVICEDIR/$CCWGROUPDEVNO/ -type l -name net*"
 	local LINKNAME=""
 
+	prepare_udevsettle_cmd
 	# polling loop to wait for net device to become available
-	if [ -e $UDEVSETTLE ]
+	if [ "$UDEVSETTLE" != "" ]
 	then
 		$UDEVSETTLE_CALL
 	fi
-- 
2.26.2