On 10/6/19 4:45 AM, Ming Lei wrote:
> If hctx becomes dead, all in-queue IO requests aimed at this hctx have to
> be re-submitted, so cover requests queued in scheduler queue.
>
> Cc: Bart Van Assche <bvanassche@xxxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Keith Busch <keith.busch@xxxxxxxxx>
> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
> ---
> block/blk-mq.c | 30 +++++++++++++++++++++++++-----
> 1 file changed, 25 insertions(+), 5 deletions(-)
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index 0b35fdbd1f17..94fd47cef1bc 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -2313,6 +2313,7 @@ static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node)
> enum hctx_type type;
> bool hctx_dead;
> struct request *rq;
> + struct elevator_queue *e;
>
> hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead);
> ctx = __blk_mq_get_ctx(hctx->queue, cpu);
> @@ -2323,12 +2324,31 @@ static int blk_mq_hctx_notify_dead(unsigned int cpu, struct hlist_node *node)
> hctx_dead = cpumask_first_and(hctx->cpumask, cpu_online_mask) >=
> nr_cpu_ids;
>
> - spin_lock(&ctx->lock);
> - if (!list_empty(&ctx->rq_lists[type])) {
> - list_splice_init(&ctx->rq_lists[type], &tmp);
> - blk_mq_hctx_clear_pending(hctx, ctx);
> + e = hctx->queue->elevator;
> + if (!e) {
> + spin_lock(&ctx->lock);
> + if (!list_empty(&ctx->rq_lists[type])) {
> + list_splice_init(&ctx->rq_lists[type], &tmp);
> + blk_mq_hctx_clear_pending(hctx, ctx);
> + }
> + spin_unlock(&ctx->lock);
> + } else if (hctx_dead) {
> + LIST_HEAD(sched_tmp);
> +
> + while ((rq = e->type->ops.dispatch_request(hctx))) {
> + if (rq->mq_hctx != hctx)
> + list_add(&rq->queuelist, &sched_tmp);
> + else
> + list_add(&rq->queuelist, &tmp);
> + }
> +
> + while (!list_empty(&sched_tmp)) {
> + rq = list_entry(sched_tmp.next, struct request,
> + queuelist);
> + list_del_init(&rq->queuelist);
> + blk_mq_sched_insert_request(rq, true, true, true);
> + }
> }
> - spin_unlock(&ctx->lock);
>
> if (list_empty(&tmp))
> return 0;
>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 247165 (AG München), GF: Felix Imendörffer
