The log indicated corruption during reading a database file.
Corruption can have various causes including faulty hardware, sudden equipment or program shutdown, unstable network, disk full, to name just a few.
Once the cause of corruption has been identified (and eliminated), there are several options for recovery.
Do you have a recent prior database back-up? If not mongod --dbpath /data/db --repair
may be an (imperfect/lossy) option.