diff options
| -rwxr-xr-x | meta/recipes-core/volatile-binds/files/mount-copybind | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/meta/recipes-core/volatile-binds/files/mount-copybind b/meta/recipes-core/volatile-binds/files/mount-copybind index 2aeaf84ddb..fddf520053 100755 --- a/meta/recipes-core/volatile-binds/files/mount-copybind +++ b/meta/recipes-core/volatile-binds/files/mount-copybind @@ -8,7 +8,10 @@ if [ $# -lt 2 ]; then exit 1 fi +# e.g. /var/volatile/lib spec=$1 + +# e.g. /var/lib mountpoint=$2 if [ $# -gt 2 ]; then @@ -20,15 +23,34 @@ fi [ -n "$options" ] && options=",$options" mkdir -p "${spec%/*}" + if [ -d "$mountpoint" ]; then - if [ ! -d "$spec" ]; then + + if [ -d "$spec" ]; then + specdir_existed=yes + else + specdir_existed=no mkdir "$spec" - cp -pPR "$mountpoint"/. "$spec/" + fi + + # Fast version of calculating `dirname ${spec}`/.`basename ${spec}`-work + overlay_workdir="${spec%/*}/.${spec##*/}-work" + mkdir "${overlay_workdir}" + + # Try to mount using overlay, which is must faster than copying files. + # If that fails, fall back to slower copy. + if ! mount -t overlay overlay -olowerdir="$mountpoint",upperdir="$spec",workdir="$overlay_workdir" "$mountpoint" > /dev/null 2>&1; then + + if [ "$specdir_existed" != "yes" ]; then + cp -pPR "$mountpoint"/. "$spec/" + fi + + mount -o "bind$options" "$spec" "$mountpoint" fi elif [ -f "$mountpoint" ]; then if [ ! -f "$spec" ]; then cp -pP "$mountpoint" "$spec" fi -fi -mount -o "bind$options" "$spec" "$mountpoint" + mount -o "bind$options" "$spec" "$mountpoint" +fi |