From: Chen Qi <[email protected]> This patch tries to make a union mount in live image. For example, if aufs is enabled with the aufs-enable.scc configuration fragment, the init-live.sh script will use aufs to make a union mount.
Although overlayfs is not supported by Yocto kernel yet, this patch still takes it into consideration with the expect that the related code should at least serve as a placeholder. [YOCTO #1487] [YOCTO #4761] Signed-off-by: Chen Qi <[email protected]> --- meta/recipes-core/initrdscripts/files/init-live.sh | 63 +++++++++++++++++--- 1 file changed, 56 insertions(+), 7 deletions(-) diff --git a/meta/recipes-core/initrdscripts/files/init-live.sh b/meta/recipes-core/initrdscripts/files/init-live.sh index 00c2558..9804504 100644 --- a/meta/recipes-core/initrdscripts/files/init-live.sh +++ b/meta/recipes-core/initrdscripts/files/init-live.sh @@ -135,15 +135,64 @@ do sleep 1 done +# Try to make a union mount of the root image. +# If no unification filesystem is available, mount the image read-only. +mount_and_boot() { + mkdir $ROOT_MOUNT + mknod /dev/loop0 b 7 0 2>/dev/null + + # determine which unification filesystem to use + union_fs_type="" + if grep -q -w "overlayfs" /proc/filesystems; then + union_fs_type="overlayfs" + elif grep -q -w "aufs" /proc/filesystems; then + union_fs_type="aufs" + else + union_fs_type="" + fi + + # make a union mount if possible + case $union_fs_type in + "overlayfs") + mkdir -p /rootfs.ro /rootfs.rw + if ! mount -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE /rootfs.ro; then + rm -rf /rootfs.ro /rootfs.rw + fatal "Could not mount rootfs image" + else + mount -t tmpfs -o rw,noatime,mode=755 tmpfs /rootfs.rw + mount -t overlayfs -o "lowerdir=/rootfs.ro,upperdir=/rootfs.rw" overlayfs $ROOT_MOUNT + mkdir -p $ROOT_MOUNT/rootfs.ro $ROOT_MOUNT/rootfs.rw + mount --move /rootfs.ro $ROOT_MOUNT/rootfs.ro + mount --move /rootfs.rw $ROOT_MOUNT/rootfs.rw + fi + ;; + "aufs") + mkdir -p /rootfs.ro /rootfs.rw + if ! mount -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE /rootfs.ro; then + rm -rf /rootfs.ro /rootfs.rw + fatal "Could not mount rootfs image" + else + mount -t tmpfs -o rw,noatime,mode=755 tmpfs /rootfs.rw + mount -t aufs -o "dirs=/rootfs.rw=rw:/rootfs.ro=ro" aufs $ROOT_MOUNT + mkdir -p $ROOT_MOUNT/rootfs.ro $ROOT_MOUNT/rootfs.rw + mount --move /rootfs.ro $ROOT_MOUNT/rootfs.ro + mount --move /rootfs.rw $ROOT_MOUNT/rootfs.rw + fi + ;; + "") + if ! mount -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE $ROOT_MOUNT ; then + fatal "Could not mount rootfs image" + fi + ;; + esac + + # boot the image + boot_live_root +} + case $label in boot) - mkdir $ROOT_MOUNT - mknod /dev/loop0 b 7 0 2>/dev/null - if ! $MOUNT -o rw,loop,noatime,nodiratime /media/$i/$ISOLINUX/$ROOT_IMAGE $ROOT_MOUNT ; then - fatal "Could not mount rootfs image" - else - boot_live_root - fi + mount_and_boot ;; install|install-efi) if [ -f /media/$i/$ISOLINUX/$ROOT_IMAGE ] ; then -- 1.7.9.5 _______________________________________________ Openembedded-core mailing list [email protected] http://lists.openembedded.org/mailman/listinfo/openembedded-core
