From 1959d21232931dfa686769a21161413f10d6652f Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 6 Jul 2006 10:18:05 +0200 Subject: [PATCH] [PATCH] Only the first two bits in bio->bi_rw and rq->flags match Not three, as assumed. This causes the barrier bit to be needlessly set for some IO. Signed-off-by: Jens Axboe --- block/ll_rw_blk.c | 4 ++-- include/linux/blktrace_api.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/block/ll_rw_blk.c b/block/ll_rw_blk.c index ab17c7224bb..61d6b3c65b6 100644 --- a/block/ll_rw_blk.c +++ b/block/ll_rw_blk.c @@ -3491,8 +3491,8 @@ EXPORT_SYMBOL(end_request); void blk_rq_bio_prep(request_queue_t *q, struct request *rq, struct bio *bio) { - /* first three bits are identical in rq->flags and bio->bi_rw */ - rq->flags |= (bio->bi_rw & 7); + /* first two bits are identical in rq->flags and bio->bi_rw */ + rq->flags |= (bio->bi_rw & 3); rq->nr_phys_segments = bio_phys_segments(q, bio); rq->nr_hw_segments = bio_hw_segments(q, bio); diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h index 2346a1db856..7520cc1ff9e 100644 --- a/include/linux/blktrace_api.h +++ b/include/linux/blktrace_api.h @@ -148,7 +148,7 @@ static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq, u32 what) { struct blk_trace *bt = q->blk_trace; - int rw = rq->flags & 0x07; + int rw = rq->flags & 0x03; if (likely(!bt)) return; -- 2.20.1