Make fancontrol more rebust against kernel driver changes
(bnc#529483).

--- lm_sensors-3.1.1.orig/prog/pwm/fancontrol	(révision 5743)
+++ lm_sensors-3.1.1/prog/pwm/fancontrol	(copie de travail)
@@ -3,12 +3,12 @@
 # Simple script implementing a temperature dependent fan speed control
 # Supported Linux kernel versions: 2.6.5 and later
 #
-# Version 0.68
+# Version 0.70
 #
 # Usage: fancontrol [CONFIGFILE]
 #
 # Dependencies:
-#   bash, egrep, sed, cut, sleep, lm_sensors :)
+#   bash, egrep, sed, cut, sleep, readlink, lm_sensors :)
 #
 # Please send any questions, comments or success stories to
 # marius.reiner@hdev.de
@@ -55,6 +55,8 @@
 
 	# grep configuration from file
 	INTERVAL=`egrep '^INTERVAL=.*$' $1 | sed -e 's/INTERVAL=//g'`
+	DEVPATH=`egrep '^DEVPATH=.*$' $1 | sed -e 's/DEVPATH= *//g'`
+	DEVNAME=`egrep '^DEVNAME=.*$' $1 | sed -e 's/DEVNAME= *//g'`
 	FCTEMPS=`egrep '^FCTEMPS=.*$' $1 | sed -e 's/FCTEMPS=//g'`
 	MINTEMP=`egrep '^MINTEMP=.*$' $1 | sed -e 's/MINTEMP=//g'`
 	MAXTEMP=`egrep '^MAXTEMP=.*$' $1 | sed -e 's/MAXTEMP=//g'`
@@ -152,6 +154,108 @@
 	echo
 }
 
+function DevicePath()
+{
+	if [ -h "$1/device" ]
+	then
+		readlink -f "$1/device" | sed -e 's/^\/sys\///'
+	fi
+}
+
+function DeviceName()
+{
+	if [ -r "$1/name" ]
+	then
+		cat "$1/name" | sed -e 's/[[:space:]=]/_/g'
+	elif [ -r "$1/device/name" ]
+	then
+		cat "$1/device/name" | sed -e 's/[[:space:]=]/_/g'
+	fi
+}
+
+function ValidateDevices()
+{
+	local OLD_DEVPATH="$1" OLD_DEVNAME="$2" outdated=0
+	local entry device name path
+
+	for entry in $OLD_DEVPATH
+	do
+		device=`echo "$entry" | sed -e 's/=[^=]*$//'`
+		path=`echo "$entry" | sed -e 's/^[^=]*=//'`
+
+		if [ "`DevicePath "$device"`" != "$path" ]
+		then
+			echo "Device path of $device has changed"
+			outdated=1
+		fi
+	done
+
+	for entry in $OLD_DEVNAME
+	do
+		device=`echo "$entry" | sed -e 's/=[^=]*$//'`
+		name=`echo "$entry" | sed -e 's/^[^=]*=//'`
+
+		if [ "`DeviceName "$device"`" != "$name" ]
+		then
+			echo "Device name of $device has changed"
+			outdated=1
+		fi
+	done
+
+	return $outdated
+}
+
+# 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+	local outdated=0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+			outdated=1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 required kernel"
+		echo "modules haven't been loaded, or your configuration file is outdated."
+		echo "In the latter case, you should run pwmconfig again."
+	fi
+
+	return $outdated
+}
+
 if [ -f "$1" ]
 then
 	LoadConfig $1
@@ -166,8 +270,12 @@
 elif echo "${AFCPWM[0]}" | egrep -q '^hwmon[0-9]'
 then
 	DIR=/sys/class/hwmon
+elif echo "${AFCPWM[0]}" | egrep -q '^[1-9]*[0-9]-[0-9abcdef]{4}'
+then
+	DIR=/sys/bus/i2c/devices
 else
-	DIR=/sys/bus/i2c/devices
+	echo "$0: Invalid path to sensors"
+	exit 1
 fi
 
 if [ ! -d $DIR ]
@@ -177,6 +285,19 @@
 fi
 cd $DIR
 
+# Check for configuration change
+if [ -z "$DEVPATH" -o -z "$DEVNAME" ]
+then
+	echo "Configuration is too old, please run pwmconfig again"
+	exit 1
+fi
+if ! ValidateDevices "$DEVPATH" "$DEVNAME"
+then
+	echo "Configuration appears to be outdated, please run pwmconfig again"
+	exit 1
+fi
+CheckFiles || exit 1
+
 if [ -f "$PIDFILE" ]
 then
 	echo "File $PIDFILE exists, is fancontrol already running?"
--- lm_sensors-3.1.1.orig/prog/pwm/pwmconfig	(révision 5743)
+++ lm_sensors-3.1.1/prog/pwm/pwmconfig	(copie de travail)
@@ -42,6 +42,12 @@
 	exit 1
 fi
 
+if [ "`id -u`" != "0" ]
+then
+	echo "You need to be root to run this script."
+	exit 1
+fi
+
 echo "# pwmconfig revision $REVISION ($REVDATE)"
 echo 'This program will search your sensors for pulse width modulation (pwm)'
 echo 'controls, and test each one to see if it controls a fan on'
@@ -258,7 +264,7 @@
 			GOODPWM="$GOODPWM $i"
 		fi
 	else
-		NOTROOT=1
+		echo "Can't write to $i, skipping."
 	fi
 done
 
@@ -302,13 +308,6 @@
 	exit 1
 fi
 
-if [ "$NOTROOT" = "1" ]
-then
-	echo 'As you are not root, we cannot write the PWM settings.'
-	echo 'Please run as root to continue.'
-	exit 1
-fi
-
 echo 'Warning!!! This program will stop your fans, one at a time,'
 echo "for approximately $DELAY seconds each!!!"
 echo 'This may cause your processor temperature to rise!!!'
@@ -540,6 +539,57 @@
 	exit 1
 fi
 
+function DevicePath()
+{
+	if [ -h "$1/device" ]
+	then
+		readlink -f "$1/device" | sed -e 's/^\/sys\///'
+	fi
+}
+
+function DeviceName()
+{
+	if [ -r "$1/name" ]
+	then
+		cat "$1/name" | sed -e 's/[[:space:]=]/_/g'
+	elif [ -r "$1/device/name" ]
+	then
+		cat "$1/device/name" | sed -e 's/[[:space:]=]/_/g'
+	fi
+}
+
+function ValidateDevices()
+{
+	local OLD_DEVPATH="$1" OLD_DEVNAME="$2" outdated=0
+	local entry device name path
+
+	for entry in $OLD_DEVPATH
+	do
+		device=`echo "$entry" | sed -e 's/=[^=]*$//'`
+		path=`echo "$entry" | sed -e 's/^[^=]*=//'`
+
+		if [ "`DevicePath "$device"`" != "$path" ]
+		then
+			echo "Device path of $device has changed"
+			outdated=1
+		fi
+	done
+
+	for entry in $OLD_DEVNAME
+	do
+		device=`echo "$entry" | sed -e 's/=[^=]*$//'`
+		name=`echo "$entry" | sed -e 's/^[^=]*=//'`
+
+		if [ "`DeviceName "$device"`" != "$name" ]
+		then
+			echo "Device name of $device has changed"
+			outdated=1
+		fi
+	done
+
+	return $outdated
+}
+
 function AskPath()
 {
 	echo -n 'What should be the path to your fancontrol config file (/etc/fancontrol)? '
@@ -567,6 +617,8 @@
 
 function LoadConfig()
 {
+	local OLD_DEVPATH OLD_DEVNAME
+
 	# Nothing to do
 	if [ ! -f "$1" ]
 	then
@@ -576,6 +628,8 @@
 
 	echo "Loading configuration from $1 ..."
 	INTERVAL=`egrep '^INTERVAL=.*$' $1 | sed -e 's/INTERVAL= *//g'`
+	OLD_DEVPATH=`egrep '^DEVPATH=.*$' $1 | sed -e 's/DEVPATH= *//g'`
+	OLD_DEVNAME=`egrep '^DEVNAME=.*$' $1 | sed -e 's/DEVNAME= *//g'`
 	FCTEMPS=`egrep '^FCTEMPS=.*$' $1 | sed -e 's/FCTEMPS= *//g'`
 	FCFANS=`egrep '^FCFANS=.*$' $1 | sed -e 's/FCFANS= *//g'`
 	MINTEMP=`egrep '^MINTEMP=.*$' $1 | sed -e 's/MINTEMP= *//g'`
@@ -586,16 +640,12 @@
 	MAXPWM=`egrep '^MAXPWM=.*$' $1 | sed -e 's/MAXPWM= *//g'`
 
 	# Check for configuration change
-	local item
-	for item in $FCFANS
-	do
-		if [ ! -f "`echo $item | sed -e 's/=.*$//'`" ]
-		then
-			echo "Configuration appears to be outdated, discarded"
-			ClearConfig
-			return 0
-		fi
-	done
+	if ! ValidateDevices "$OLD_DEVPATH" "$OLD_DEVNAME"
+	then
+		echo "Configuration appears to be outdated, discarded"
+		ClearConfig
+		return 0
+	fi
 }
 
 LoadConfig $FCCONFIG
@@ -676,14 +726,74 @@
 	echo "OK, using $fanval"
 }
 
+# Remember the path and name of each device with at least one
+# reference (pwm, temp or fan) in the configuration file.
+# This function sets globals DEVPATH and DEVNAME as a side effect.
+function RememberDevices()
+{
+	local used entry device name path tempfandev pwmdev
+	DEVPATH=""
+	DEVNAME=""
+
+	for device in $DEVICES
+	do
+		device=`echo "$device" | sed -e 's/\/.*$//'`
+
+		used=0
+		for entry in $1 $2
+		do
+			pwmdev=`echo "$entry" | sed -e 's/\/.*$//'`
+			tempfandev=`echo "$entry" | sed -e 's/^[^=]*=//' -e 's/\/.*$//'`
+
+			if [ "$device" = "$pwmdev" -o "$device" = "$tempfandev" ]
+			then
+				used=1
+			fi
+		done
+		if [ "$used" -eq 0 ]
+		then
+			continue
+		fi
+
+		# Record the device path and name. This lets the fancontrol
+		# script check that they didn't change. If they did, then the
+		# configuration file can no longer be trusted.
+		path=`DevicePath "$device"`
+		if [ -z "$DEVPATH" ]
+		then
+			DEVPATH="$device=$path"
+		else
+			DEVPATH="$DEVPATH $device=$path"
+		fi
+
+		name=`DeviceName "$device"`
+		if [ -z "$DEVNAME" ]
+		then
+			DEVNAME="$device=$name"
+		else
+			DEVNAME="$DEVNAME $device=$name"
+		fi
+	done
+}
+
 function SaveConfig()
 {
+	RememberDevices "$FCTEMPS" "$FCFANS"
+
 	echo
 	echo "Saving configuration to $FCCONFIG..."
 	tmpfile=`mktemp -t pwmcfg.XXXXXXXXXX` || { echo "$0: Cannot create temporary file" >&2; exit 1;  }
 	trap " [ -f \"$tmpfile\" ] && /bin/rm -f -- \"$tmpfile\"" 0 1 2 3 13 15
 	echo "# Configuration file generated by pwmconfig, changes will be lost" >$tmpfile
-	echo -e "INTERVAL=$INTERVAL\nFCTEMPS=$FCTEMPS\nFCFANS=$FCFANS\nMINTEMP=$MINTEMP\nMAXTEMP=$MAXTEMP\nMINSTART=$MINSTART\nMINSTOP=$MINSTOP" >>$tmpfile
+	echo "INTERVAL=$INTERVAL" >>$tmpfile
+	echo "DEVPATH=$DEVPATH" >>$tmpfile
+	echo "DEVNAME=$DEVNAME" >>$tmpfile
+	echo "FCTEMPS=$FCTEMPS" >>$tmpfile
+	echo "FCFANS=$FCFANS" >>$tmpfile
+	echo "MINTEMP=$MINTEMP" >>$tmpfile
+	echo "MAXTEMP=$MAXTEMP" >>$tmpfile
+	echo "MINSTART=$MINSTART" >>$tmpfile
+	echo "MINSTOP=$MINSTOP" >>$tmpfile
 	[ -n "$MINPWM" ] && echo "MINPWM=$MINPWM" >>$tmpfile
 	[ -n "$MAXPWM" ] && echo "MAXPWM=$MAXPWM" >>$tmpfile
 	mv $tmpfile $FCCONFIG
--- lm_sensors-3.1.1.orig/prog/pwm/fancontrol.8	(révision 5743)
+++ lm_sensors-3.1.1/prog/pwm/fancontrol.8	(copie de travail)
@@ -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
 
@@ -38,13 +38,21 @@
 This variable defines at which interval in seconds the main loop of
 \fBfancontrol\fP will be executed
 .TP
+.B DEVPATH
+Maps hwmon class devices to physical devices. This lets \fBfancontrol\fP
+check that the configuration file is still up-to-date.
+.TP
+.B DEVNAME
+Records hwmon class device names. This lets \fBfancontrol\fP check that
+the configuration file is still up-to-date.
+.TP
 .B FCTEMPS
 Maps PWM outputs to temperature sensors so \fBfancontrol\fP knows which
 temperature sensors should be used for calculation of new values for
 the corresponding PWM outputs.
 .TP
 .B FCFANS
-FCFANS records the association between a PWM and a fan.
+Records the association between a PWM output and a fan input.
 Then \fBfancontrol\fP can check the fan speed and restart it if it
 stops unexpectedly.
 .TP
@@ -92,6 +100,12 @@
 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 devices
+do exist and match what they were at configuration time, and 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