From 673643490b9a0eb3b25633abe604f62b8f63dba1 Mon Sep 17 00:00:00 2001
From: Li Nan <linan122@huawei.com>
Date: Sat, 1 Jul 2023 16:05:29 +0800
Subject: [PATCH] md/raid10: use dereference_rdev_and_rrdev() to get devices
Git-commit: 673643490b9a0eb3b25633abe604f62b8f63dba1
Patch-mainline: v6.6-rc1
References: git-fixes
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.
(Coly Li: rebased for Linux v5.14 based SUSE kernel)
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@huawei.com>
Link: https://lore.kernel.org/r/20230701080529.2684932-4-linan666@huaweicloud.com
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/raid10.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1347,11 +1347,9 @@ retry_wait:
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;
@@ -1787,10 +1785,9 @@ retry_discard:
*/
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;