add a struct request pointer to the request structure

This adds a struct request pointer to the request structure for the
second data phase (bidi for now). A request queue supporting bidi
requests sets QUEUE_FLAG_BIDI. This prevents sending bidi requests to
a non-bidi queue.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
FUJITA Tomonori 2007-07-16 08:52:14 +02:00 committed by Jens Axboe
parent efba1a31f3
commit abae1fde63
2 changed files with 6 additions and 0 deletions

View File

@ -256,6 +256,7 @@ static void rq_init(request_queue_t *q, struct request *rq)
rq->end_io = NULL;
rq->end_io_data = NULL;
rq->completion_data = NULL;
rq->next_rq = NULL;
}
/**

View File

@ -317,6 +317,9 @@ struct request {
*/
rq_end_io_fn *end_io;
void *end_io_data;
/* for bidi */
struct request *next_rq;
};
/*
@ -486,6 +489,7 @@ struct request_queue
#define QUEUE_FLAG_REENTER 6 /* Re-entrancy avoidance */
#define QUEUE_FLAG_PLUGGED 7 /* queue is plugged */
#define QUEUE_FLAG_ELVSWITCH 8 /* don't use elevator, just do FIFO */
#define QUEUE_FLAG_BIDI 9 /* queue supports bidi requests */
enum {
/*
@ -550,6 +554,7 @@ enum {
#define blk_sorted_rq(rq) ((rq)->cmd_flags & REQ_SORTED)
#define blk_barrier_rq(rq) ((rq)->cmd_flags & REQ_HARDBARRIER)
#define blk_fua_rq(rq) ((rq)->cmd_flags & REQ_FUA)
#define blk_bidi_rq(rq) ((rq)->next_rq != NULL)
#define list_entry_rq(ptr) list_entry((ptr), struct request, queuelist)