Re: [PATCH -next 2/3] md/raid10: convert resync_lock to use seqlock

[Guoqing Jiang]

Hi,

On 8/29/22 9:15 PM, Yu Kuai wrote:
> +static bool wait_barrier_nolock(struct r10conf *conf)
> +{
> +	unsigned int seq = raw_read_seqcount(&conf->resync_lock.seqcount);
> +
> +	if (seq & 1)
> +		return false;
> +
> +	if (READ_ONCE(conf->barrier))
> +		return false;
> +
> +	atomic_inc(&conf->nr_pending);
> +	if (!read_seqcount_retry(&conf->resync_lock.seqcount, seq))

I think 'seq' is usually get from read_seqcount_begin.

> +		return true;
> +
> +	atomic_dec(&conf->nr_pending);
> +	return false;
> +

Thanks,
Guoqing