bio_endio — end I/O on a bio
| void fsfuncbio_endio ( | struct bio * bio, | 
| int error ); | 
   bio_endio will end I/O on the whole bio. bio_endio is the
   preferred way to end I/O on a bio, it takes care of clearing
   BIO_UPTODATE on error. error is 0 on success, and and one of the
   established -Exxxx (-EIO, for instance) error values in case
   something went wrong. No one should call bi_end_io directly on a
   bio unless they own it and thus know that it has an end_io
   function.