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@xxxxxxxxxxxxx>
---
block/ll_rw_blk.c | 1 +
include/linux/blkdev.h | 5 +++++
2 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c
index c99b463..a133d51 100644
--- a/block/ll_rw_blk.c
+++ b/block/ll_rw_blk.c
@@ -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;
}
/**
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1645354..7accf7e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -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)
--
1.4.4.4
-
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