Commit 67364349 authored by Li Nan's avatar Li Nan Committed by Song Liu
Browse files

md/raid10: use dereference_rdev_and_rrdev() to get devices 



Commit 2ae6aaf7 ("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: d30588b2 ("md/raid10: improve raid10 discard request")
Fixes: f2e7e269 ("md/raid10: pull the code that wait for blocked dev into one function")
Signed-off-by: default avatarLi Nan <linan122@huawei.com>
Link: https://lore.kernel.org/r/20230701080529.2684932-4-linan666@huaweicloud.com


Signed-off-by: default avatarSong Liu <song@kernel.org>
parent b99f8fd2

drivers/md/raid10.c

+5 −10
Original line number Diff line number Diff line
@@ -1350,11 +1350,9 @@ 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;
@@ -1789,15 +1787,12 @@ 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;



		rdev = dereference_rdev_and_rrdev(&conf->mirrors[disk], &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)))