boot-stage-1: Don't run `fsck' when on battery power.

svn path=/nixos/trunk/; revision=13484

boot/boot-stage-1-init.sh

@@ -138,6 +138,26 @@ fi
 if test -n "$debug1devices"; then fail; fi
 
 
+# Return true if the machine is on AC power, or if we can't determine
+# whether it's on AC power.
+onACPower () {
+    if test -d "/proc/acpi/battery"; then
+	if ls /proc/acpi/battery/BAT[0-9]* > /dev/null 2>&1; then
+	    if cat /proc/acpi/battery/BAT*/state	\
+	       | grep "^charging state"			\
+	       | grep -q "discharg" ; then
+		false
+	    else
+		true
+	    fi
+	else
+	    true
+	fi
+    else
+	true
+    fi
+}
+
 # Function for mounting a file system.
 mountFS() {
     local device="$1"
@@ -158,6 +178,7 @@ mountFS() {
     fi
 
     if test -n "$mustCheck"; then
+	if onACPower; then
             FSTAB_FILE="/etc/mtab" fsck -V -v -C -a "$device"
             fsckResult=$?
 
@@ -176,6 +197,10 @@ mountFS() {
 		echo "fsck on $device failed."
 		fail
             fi
+	else
+            # Don't run `fsck' if the machine is on battery power.
+	    echo "on battery power, so \`fsck' not run on \`$device'"
+	fi
     fi
 
     # Mount read-writable.