From: Ming Lei <ming.lei@canonical.com>
Date: Mon, 30 Nov 2015 08:05:49 +0000 (+0800)
Subject: blk-merge: fix computing bio->bi_seg_front_size in case of single segment
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a88d32af18b8a6616128c971f766eaf545966405;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

blk-merge: fix computing bio->bi_seg_front_size in case of single segment

When bio has only one physical segment, we should set bio's
bi_seg_front_size as the real(final) size of the single segment.

Fixes: 02e707424c2ea(blk-merge: fix blk_bio_segment_split)
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
---

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 41a55ba0d78e..e01405a3e8b3 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -103,6 +103,9 @@ static struct bio *blk_bio_segment_split(struct request_queue *q,
 			bvprv = bv;
 			bvprvp = &bvprv;
 			sectors += bv.bv_len >> 9;
+
+			if (nsegs == 1 && seg_size > front_seg_size)
+				front_seg_size = seg_size;
 			continue;
 		}
 new_segment: