need help in understanding basics of block device driver

[nidhi mittal <nidhimittal19@xxxxxxxxx>]

i was studying writing block device driver --- i had some confusions like :

in gyst :

when you actually transfer data in request processing function
using req->current_nr_sectors
from req->buffer
in while elv_next_request loop
and if its transferred successfully book does end_request(req,1)

then my ques is
Q1.  end_request doesnt end the request but ends the part of request
what is that part --- a bio OR a segment or what ?

by seeing current_nr_sectors it seems it transfer segment by segment ---
but seeing req->buffer (equivalent to bio_data(current bio)) seems transferring bio by bio ??


Nidhi

-- 
Thanks & Regards 
Nidhi