[PATCH 5.10.y] dm-writecache: report I/O error if flush failed

[Sasha Levin <sashal@kernel.org>]

From: Mikulas Patocka <mpatocka@redhat.com>

[ Upstream commit 78a6afc2999d26e5a30a56db77db34c22b88f5d5 ]

There was a bug that if writecache_flush fails due to I/O error, the
error is not reported in the FUA bio. This commit fixes it.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Assisted-by: opencode:big-pickle
Cc: stable@vger.kernel.org
Fixes: 48debafe4f2f ("dm: add writecache target")
[ sashal: adapted the change to writecache_map() because writecache_map_write() has not been split out ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/md/dm-writecache.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-writecache.c b/drivers/md/dm-writecache.c
index 1b7d89794c6a3..f8b671299c854 100644
--- a/drivers/md/dm-writecache.c
+++ b/drivers/md/dm-writecache.c
@@ -1454,10 +1454,13 @@ static int writecache_map(struct dm_target *ti, struct bio *bio)
 		} while (bio->bi_iter.bi_size);
 
 		if (unlikely(bio->bi_opf & REQ_FUA ||
-			     wc->uncommitted_blocks >= wc->autocommit_blocks))
+			     wc->uncommitted_blocks >= wc->autocommit_blocks)) {
 			writecache_flush(wc);
-		else
+			if (writecache_has_error(wc))
+				bio->bi_status = BLK_STS_IOERR;
+		} else {
 			writecache_schedule_autocommit(wc);
+		}
 		goto unlock_submit;
 	}
 
-- 
2.53.0