before: /dev/mmcblk0p4               1.6G   99M  1.4G   7% /oem
after: /dev/mmcblk0p4                28G  101M   26G   1% /oem


(ODROIDC)root@odroid:~# ./resize-snappy-writable.sh
DEVNAME=/dev/mmcblk0p4
DEV=mmcblk0p4
BLOCKPATH=/sys/class/block/mmcblk0p4
PARTITION=4
REALPATH=/sys/devices/platform/aml_sdhc.0/mmc_host/sd/sd:aaaa/block/mmcblk0/mmcblk0p4
PARENTPATH=/sys/devices/platform/aml_sdhc.0/mmc_host/sd/sd:aaaa/block/mmcblk0
BLK=179:0
BLKDEV=/dev/mmcblk0
CHANGED: partition=4 start=4333568 old: size=3280896 end=7614464 new: size=58000384,end=62333952
resize2fs 1.42.12 (29-Aug-2014)
Filesystem at /dev/mmcblk0p4 is mounted on /writable; on-line resizing required
old_desc_blocks = 1, new_desc_blocks = 2
The filesystem on /dev/mmcblk0p4 is now 7250048 (4k) blocks long.