| #!/bin/sh |
| |
| . /etc/default/rcS |
| |
| [ "$ROOTFS_READ_ONLY" = "no" ] && exit 0 |
| |
| is_on_read_only_partition () { |
| DIRECTORY=$1 |
| dir=`readlink -f $DIRECTORY` |
| while true; do |
| if [ ! -d "$dir" ]; then |
| echo "ERROR: $dir is not a directory" |
| exit 1 |
| else |
| for flag in `awk -v dir=$dir '{ if ($2 == dir) { print "FOUND"; split($4,FLAGS,",") } }; \ |
| END { for (f in FLAGS) print FLAGS[f] }' < /proc/mounts`; do |
| [ "$flag" = "FOUND" ] && partition="read-write" |
| [ "$flag" = "ro" ] && { partition="read-only"; break; } |
| done |
| if [ "$dir" = "/" -o -n "$partition" ]; then |
| break |
| else |
| dir=`dirname $dir` |
| fi |
| fi |
| done |
| [ "$partition" = "read-only" ] && echo "yes" || echo "no" |
| } |
| |
| if [ "$1" = "start" ] ; then |
| if [ `is_on_read_only_partition /var/lib` = "yes" ]; then |
| grep -q "tmpfs /var/volatile" /proc/mounts || mount /var/volatile |
| mkdir -p /var/volatile/lib |
| mkdir -p /var/volatile/.lib-work |
| # Try to mount using overlay, which is much faster than copying |
| # files. If that fails, fallback to the slower copy |
| if ! mount -t overlay overlay -olowerdir=/var/lib,upperdir=/var/volatile/lib,workdir=/var/volatile/.lib-work /var/lib > /dev/null 2>&1; then |
| cp -a /var/lib/* /var/volatile/lib |
| mount --bind /var/volatile/lib /var/lib |
| fi |
| fi |
| fi |
| |