[PATCH 3/3] md/raid10: use get_rdev_repl_from_mirror() to get devices

From: linan666
Date: Tue Jun 27 2023 - 21:59:14 EST


From: Li Nan <linan122@xxxxxxxxxx>

Commit 2ae6aaf76912 ("md/raid10: fix io loss while replacement replace
rdev") reads replacement first to prevent io loss. However, there are same
issue in wait_blocked_dev() and raid10_handle_discard(), too. Fix it by
using get_rdev_repl_from_mirror() to get devices.

Fixes: d30588b2731f ("md/raid10: improve raid10 discard request")
Fixes: f2e7e269a752 ("md/raid10: pull the code that wait for blocked dev into one function")
Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
---
drivers/md/raid10.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index eaaf6307ddda..2d55374d8b22 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1376,11 +1376,9 @@ static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio)
blocked_rdev = NULL;
rcu_read_lock();
for (i = 0; i < conf->copies; i++) {
- struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
- struct md_rdev *rrdev = rcu_dereference(
- conf->mirrors[i].replacement);
- if (rdev == rrdev)
- rrdev = NULL;
+ struct md_rdev *rdev, *rrdev;
+
+ get_rdev_repl_from_mirror(&conf->mirrors[i], &rdev, &rrdev);
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
atomic_inc(&rdev->nr_pending);
blocked_rdev = rdev;
@@ -1816,15 +1814,12 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
*/
rcu_read_lock();
for (disk = 0; disk < geo->raid_disks; disk++) {
- struct md_rdev *rdev = rcu_dereference(conf->mirrors[disk].rdev);
- struct md_rdev *rrdev = rcu_dereference(
- conf->mirrors[disk].replacement);
+ struct md_rdev *rdev, *rrdev;

+ get_rdev_repl_from_mirror(&conf->mirrors[disk], &rdev, &rrdev);
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