From 6ac45aeb6bcad38a2783a7d6e5da4c469497eeb0 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@canonical.com>
Date: Tue, 20 Oct 2015 23:13:53 +0800
Subject: [PATCH] block: avoid to merge splitted bio
The splitted bio has been already too fat to merge, so mark it
as NOMERGE.
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---
block/blk-merge.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 22293fdf6514..de5716d8e525 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -139,6 +139,9 @@ void blk_queue_split(struct request_queue *q, struct bio **bio,
bio_set_flag(res, BIO_SEG_VALID);
if (split) {
+ /* there isn't chance to merge the splitted bio */
+ split->bi_rw |= REQ_NOMERGE;
+
bio_chain(split, *bio);
generic_make_request(*bio);
*bio = split;