From: Yu Kuai <yukuai3@xxxxxxxxxx> [ 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@xxxxxxxxx> Link: https://lore.kernel.org/linux-raid/e2f96772-bfbc-f43b-6da1-f520e5164536@xxxxxxxxx/ Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx> Signed-off-by: Song Liu <song@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230512015610.821290-3-yukuai1@xxxxxxxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/md/md.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index 12392a4fb9c0d..3c2364d0d88f3 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -4615,11 +4615,21 @@ 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); } -- 2.39.2