The libmount provides way how to deal with parsing errors in fstab --
on error callback function is executed and according to the return
libmount manipulate with the malformed line, possible are three
states:
1/ fatal error; all file ignored (callback rc < 0)
2/ recoverable error; malformed line ignored (callback rc > 0)
3/ ignore the error (callback rc == 0)
The 2/ is the default if no callback specified.
Unfortunately our utils uses 3/. The correct way is to use 2/.