md: fix data corruption for raid456 when reshape restart while grow up

[ Upstream commit 873f50ece41aad5c4f788a340960c53774b5526e ]

Currently, if reshape is interrupted, echo "reshape" to sync_action will
restart reshape from scratch, for example:

echo frozen > sync_action
echo reshape > sync_action

This will corrupt data before reshape_position if the array is growing,
fix the problem by continue reshape from reshape_position.

Reported-by: Peter Neuwirth <reddunur@online.de>
Link: https://lore.kernel.org/linux-raid/e2f96772-bfbc-f43b-6da1-f520e5164536@online.de/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230512015610.821290-3-yukuai1@huaweicloud.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Yu Kuai 2023-05-12 09:56:07 +08:00 committed by Greg Kroah-Hartman
parent 4181c30a2c
commit 09539f9e20

View File

@ -4743,11 +4743,21 @@ action_store(struct mddev *mddev, const char *page, size_t len)
return -EINVAL;
err = mddev_lock(mddev);
if (!err) {
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
err = -EBUSY;
else {
} else if (mddev->reshape_position == MaxSector ||
mddev->pers->check_reshape == NULL ||
mddev->pers->check_reshape(mddev)) {
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
err = mddev->pers->start_reshape(mddev);
} else {
/*
* If reshape is still in progress, and
* md_check_recovery() can continue to reshape,
* don't restart reshape because data can be
* corrupted for raid456.
*/
clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
}
mddev_unlock(mddev);
}