5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Li Nan <linan122@xxxxxxxxxx>
[ Upstream commit 673643490b9a0eb3b25633abe604f62b8f63dba1 ]
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 dereference_rdev_and_rrdev() 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>
Link: https://lore.kernel.org/r/20230701080529.2684932-4-linan666@xxxxxxxxxxxxxxx
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/md/raid10.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index ff3c97cde7699..a3a3a02d48b17 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1345,11 +1345,9 @@ 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;
+
+ rdev = dereference_rdev_and_rrdev(&conf->mirrors[i], &rrdev);
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
atomic_inc(&rdev->nr_pending);
blocked_rdev = rdev;
@@ -1785,10 +1783,9 @@ 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;
+ rdev = dereference_rdev_and_rrdev(&conf->mirrors[disk], &rrdev);
r10_bio->devs[disk].bio = NULL;
r10_bio->devs[disk].repl_bio = NULL;
--
2.40.1
