linux-kernel - [PATCH AUTOSEL 4.20 42/77] dm: fix clone_bio() to trigger blk_recount

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Date:   Thu, 14 Feb 2019 21:08:20 -0500
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Mike Snitzer <snitzer@...hat.com>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 4.20 42/77] dm: fix clone_bio() to trigger blk_recount_segments()

From: Mike Snitzer <snitzer@...hat.com>

[ Upstream commit 57c36519e4b949f89381053f7283f5d605595b42 ]

DM's clone_bio() now benefits from using bio_trim() by fixing the fact
that clone_bio() wasn't clearing BIO_SEG_VALID like bio_trim() does;
which triggers blk_recount_segments() via bio_phys_segments().

Reviewed-by: Ming Lei <ming.lei@...hat.com>
Signed-off-by: Mike Snitzer <snitzer@...hat.com>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/md/dm.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 63a7c416b224..7138e69d40e0 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1318,7 +1318,7 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio,
 
 	__bio_clone_fast(clone, bio);
 
-	if (unlikely(bio_integrity(bio) != NULL)) {
+	if (bio_integrity(bio)) {
 		int r;
 
 		if (unlikely(!dm_target_has_integrity(tio->ti->type) &&
@@ -1334,11 +1334,7 @@ static int clone_bio(struct dm_target_io *tio, struct bio *bio,
 			return r;
 	}
 
-	bio_advance(clone, to_bytes(sector - clone->bi_iter.bi_sector));
-	clone->bi_iter.bi_size = to_bytes(len);
-
-	if (unlikely(bio_integrity(bio) != NULL))
-		bio_integrity_trim(clone);
+	bio_trim(clone, sector - clone->bi_iter.bi_sector, len);
 
 	return 0;
 }
-- 
2.19.1