From 764f612c6c3c231b9c12cfae7c328ccc9c453258 Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 9 Oct 2014 23:17:35 +0800 Subject: [PATCH] blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio It isn't correct to figure out req->bi_phys_segments from bio->bi_vcnt if the bio is cloned. Signed-off-by: Ming Lei Tested-by: Jeff Mahoney Signed-off-by: Jens Axboe --- block/blk-merge.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index f71bad35b4cc..ba99351c0f58 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -97,14 +97,18 @@ void blk_recalc_rq_segments(struct request *rq) void blk_recount_segments(struct request_queue *q, struct bio *bio) { - if (test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags) && + bool no_sg_merge = !!test_bit(QUEUE_FLAG_NO_SG_MERGE, + &q->queue_flags); + + if (no_sg_merge && !bio_flagged(bio, BIO_CLONED) && bio->bi_vcnt < queue_max_segments(q)) bio->bi_phys_segments = bio->bi_vcnt; else { struct bio *nxt = bio->bi_next; bio->bi_next = NULL; - bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, false); + bio->bi_phys_segments = __blk_recalc_rq_segments(q, bio, + no_sg_merge); bio->bi_next = nxt; }