dual boot - Ubuntu can't read hard drive after booting in windows 8

I have a dual boot Ubuntu / Windows 8 system. My secondary hard drive I keep all my data, and I booted into windows, changed one file, shut down, booted back into Ubuntu, and now I can't access anything on the hard drive. In File Manager it shows icons with a small padlock on each. If I emacs a file it gives me an IO error. If I try mv it gives "Read-only file system".

I've tried rebooting, remounting, with no luck. I'm a bit lost as to what to do now. I did a scan/clean with Disk Utility and it says the disk is fine.

James

This may happen if you hibernate the windows system. Try accessing the hard drive again from windows and see if that is possible. If yes do a complete reboot and then try to access the drive from ubuntu.

If that also does not do it, try accessing the disk with superuser access (be a bit careful here though)