blk_end_io — Generic end_io function to complete a request.
int blk_end_io
(struct request * rq, int error, unsigned int nr_bytes, unsigned int bidi_bytes, int ()(struct request *) drv_callback);
the request being processed
0 for success, < 0 for error
number of bytes to complete rq
number of bytes to complete rq->next_rq
function called between completion of bios in the request and completion of the request. If the callback returns non 0, this helper returns without completion of the request.
Ends I/O on a number of bytes attached to rq and rq->next_rq. If rq has leftover, sets it up for the next range of segments.
0 - we are done with this request 1 - this request is not freed yet, it still has pending buffers.