1. Boot grub, edit your defailt command line.
2. Remove "rhgb" and "quiet" from the "linux" command line so you can see boot messages
3. Add "rescue" in their place
4. System boots to rescue mode
5. Enter your root PW when prompted
6. execute the command "mount -o remount,ro /" to remount root as read only
7. execute the command "xfs_repair -d /dev/<your root device>"
8. cross fingers, wait and reboot immediately when complete
9. there is no step 9