How to corrupt a file system
xfs_db has an option blocktrash which
Trash randomly selected filesystem metadata blocks. Trashing occurs to randomly selected bits in the chosen blocks. This command is available only in debugging versions of xfs_db. It is useful for testing
xfs_repair(8)andxfs_check(8).
For example
xfs_db -x -c blockget -c "blocktrash -s 512109 -n 1000" /dev/xfstest/testfs
dd blocks to the device where the filesystem resides. You can script this so it is repeatable. Just a few random blocks at random locations, then move on.