docker pull 时报了个很奇怪的错。。。

$ docker pull ubuntu
Using default tag: latest
latest: Pulling from library/ubuntu
50aff78429b1: Extracting [==================================================>]  42.74MB/42.74MB
f6d82e297bce: Download complete
275abb2c8a6f: Download complete
9f15a39356d6: Download complete
fc0342a94c89: Download complete
latest: Pulling from library/ubuntu
50aff78429b1: Extracting [==================================================>]  42.74MB/42.74MB
f6d82e297bce: Download complete
275abb2c8a6f: Download complete
9f15a39356d6: Download complete
fc0342a94c89: Download complete
failed to register layer: Error processing tar file(exit status 1): invalid argument