pull oracle-java7 error

   docker pull dockerfile/java:oracle-java7

The error is

2014/09/12 02:34:04 Error pulling image (oracle-java7) from dockerfile/java, write /var/lib/docker/devicemapper/mnt/ab8cf23c9d17cb3c6e644e1b43dea176c0e439df57fdc7ed855bb3443f68b292/rootfs/var/cache/oracle-jdk7-installer/jdk-7u67-linux-x64.tar.gz: read-only file system
