From c76907971ec5a7bf4a3fcff794cf243d06423b4e Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Tue, 8 Sep 2009 16:52:29 +0000
Subject: [PATCH] Check that all referenced sysfs files exist before starting.
 If not, quilt immediately. Better no fan control than fan control using an
 out-of-sync configuration file.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@5765 7894878c-1315-0410-8ee3-d5d059ff63e0
---
 CHANGES               |  1 +
 prog/pwm/fancontrol   | 54 +++++++++++++++++++++++++++++++++++++++++++
 prog/pwm/fancontrol.8 |  6 ++++-
 3 files changed, 60 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index a85f6809..489aeb82 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,7 @@ lm-sensors CHANGES file
 
 SVN-HEAD
   libsensors: Support upcoming sysfs path to i2c adapters
+  fancontrol: Check that all referenced sysfs files exist
   pwmconfig: Exit immediately if not root
   sensors.conf.default: Encourage user to not modify this file
   sensors-detect: Refer to tmp401 driver if TMP411 is detected
diff --git a/prog/pwm/fancontrol b/prog/pwm/fancontrol
index 07b43e5f..5353678d 100755
--- a/prog/pwm/fancontrol
+++ b/prog/pwm/fancontrol
@@ -152,6 +152,58 @@ function LoadConfig {
 	echo
 }
 
+# Check that all referenced sysfs files exist
+function CheckFiles {
+	local outdated=0
+
+	let fcvcount=0
+	while (( $fcvcount < ${#AFCPWM[@]} )) # go through all pwm outputs
+	do
+		pwmo=${AFCPWM[$fcvcount]}
+		if [ ! -w $pwmo ]
+		then
+			echo "Error: file $pwmo doesn't exist"
+			outdated=1
+		fi
+		let fcvcount=$fcvcount+1
+	done
+
+	let fcvcount=0
+	while (( $fcvcount < ${#AFCTEMP[@]} )) # go through all temp inputs
+	do
+		tsen=${AFCTEMP[$fcvcount]}
+		if [ ! -r $tsen ]
+		then
+			echo "Error: file $tsen doesn't exist"
+			outdated=1
+		fi
+		let fcvcount=$fcvcount+1
+	done
+
+	let fcvcount=0
+	while (( $fcvcount < ${#AFCFAN[@]} )) # go through all fan inputs
+	do
+		fan=${AFCFAN[$fcvcount]}
+		if [ ! -r $fan ]
+		then
+			echo "Error: file $fan doesn't exist"
+			outdated=1
+		fi
+		let fcvcount=$fcvcount+1
+	done
+
+	if [ $outdated -eq 1 ]
+	then
+		echo
+		echo "At least one referenced file is missing. Either some"
+		echo "required kernel modules haven't been loaded, or your"
+		echo "configuration file is outdated. In the latter case,"
+		echo "you should run pwmconfig again."
+	fi
+
+	return $outdated
+}
+
 if [ -f "$1" ]
 then
 	LoadConfig $1
@@ -181,6 +233,8 @@ then
 fi
 cd $DIR
 
+CheckFiles || exit 1
+
 if [ -f "$PIDFILE" ]
 then
 	echo "File $PIDFILE exists, is fancontrol already running?"
diff --git a/prog/pwm/fancontrol.8 b/prog/pwm/fancontrol.8
index c4574444..106b44a4 100644
--- a/prog/pwm/fancontrol.8
+++ b/prog/pwm/fancontrol.8
@@ -1,4 +1,4 @@
-.TH FANCONTROL 8 "January 2009" "lm-sensors 3"
+.TH FANCONTROL 8 "September 2009" "lm-sensors 3"
 .SH NAME
 fancontrol \- automated software based fan speed regulation
 
@@ -92,6 +92,10 @@ You have to play with the temperature values a bit to get happy. For initial
 setup I recommend using the \fBpwmconfig\fP script. Small changes can be made by
 editing the config file directly following the rules above.
 
+Upon starting, fancontrol will make sure that all referenced sysfs files
+do exist. If not, it will quit immediately, upon the assumption that the
+configuration file may be out-of-sync with the loaded kernel drivers.
+
 .SH THE ALGORITHM
 
 \fBfancontrol\fP first reads its configuration, writes it to arrays and loops its