From abae1fde63fcdd2a3abaa0d7930938d8326f83d2 Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Mon, 16 Jul 2007 08:52:14 +0200 Subject: [PATCH] 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 Signed-off-by: Jens Axboe --- block/ll_rw_blk.c | 1 + include/linux/blkdev.h | 5 +++++ 2 files changed, 6 insertions(+) diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index ef42bb2b12b6..11e4235d0b0c 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 24b474e05a44..b32564a1e105 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)