在 2023/5/29 下午9:20, Yu Kuai 写道:
> From: Yu Kuai <yukuai3@huawei.com>
>
> For md_check_recovery():
>
> 1) if 'MD_RECOVERY_RUNING' is not set, register new sync_thread.
> 2) if 'MD_RECOVERY_RUNING' is set:
> a) if 'MD_RECOVERY_DONE' is not set, don't do anything, wait for
> md_do_sync() to be done.
> b) if 'MD_RECOVERY_DONE' is set, unregister sync_thread. Current code
> expects that sync_thread is not NULL, otherwise new sync_thread will
> be registered, which will corrupt the array.
>
> Make sure md_check_recovery() won't register new sync_thread if
> 'MD_RECOVERY_RUNING' is still set, and a new WARN_ON_ONCE() is added for
> the above corruption,
>
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> ---
> drivers/md/md.c | 22 +++++++++++++++-------
> 1 file changed, 15 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index f90226e6ddf8..9da0fc906bbd 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -9397,16 +9397,24 @@ void md_check_recovery(struct mddev *mddev)
> if (mddev->sb_flags)
> md_update_sb(mddev, 0);
>
> - if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) &&
> - !test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
> - /* resync/recovery still happening */
> - clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
> - goto unlock;
> - }
> - if (mddev->sync_thread) {
> + /*
> + * Never start a new sync thread if MD_RECOVERY_RUNNING is
> + * still set.
> + */
> + if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery)) {
> + if (!test_bit(MD_RECOVERY_DONE, &mddev->recovery)) {
> + /* resync/recovery still happening */
> + clear_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
> + goto unlock;
> + }
> +
> + if (WARN_ON_ONCE(!mddev->sync_thread))
> + goto unlock;
> +
> md_reap_sync_thread(mddev);
> goto unlock;
> }
> +
> /* Set RUNNING before clearing NEEDED to avoid
> * any transients in the value of "sync_action".
> */
It makes the logical more clear.
Reviewed-by: Xiao Ni <xni@redhat.com>