Submit a bio to the block device layer for i/o
void submit_bio(int rw, struct bio * bio);
rw
whether to READ or WRITE, or maybe to READA (read ahead)
bio
The struct bio which describes the I/O
submit_bio is very similar in purpose to generic_make_request, and uses that function to do most of the work. Both are fairly rough interfaces; bio must be presetup and ready for I/O.