From: Li Nan <redacted>

After commit 4ca40c2ce099 ("md/raid10: Allow replacement device to be
replace old drive."), 'rdev' and 'replacement' could appear to be
identical. There are already checks for that in wait_blocked_dev() and
raid10_write_request(). Add check for raid10_handle_discard() now.

Signed-off-by: Li Nan <redacted>
---
 drivers/md/raid10.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index fabc340aae4f..3e6a09aaaba6 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c

@@ -1811,6 +1811,8 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
 		r10_bio->devs[disk].bio = NULL;
 		r10_bio->devs[disk].repl_bio = NULL;
 
+		if (rdev == rrdev)
+			rrdev = NULL;
 		if (rdev && (test_bit(Faulty, &rdev->flags)))
 			rdev = NULL;
 		if (rrdev && (test_bit(Faulty, &rrdev->flags)))

-- 
2.39.2