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>
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 24b474e..b32564a 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -317,6 +317,9 @@
*/
rq_end_io_fn *end_io;
void *end_io_data;
+
+ /* for bidi */
+ struct request *next_rq;
};
/*
@@ -486,6 +489,7 @@
#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 @@
#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)