Re: [PATCH v2 1/2] io-wq: allow grabbing existing io-wq

From: Pavel Begunkov
Date: Mon Jan 27 2020 - 19:19:35 EST


On 28/01/2020 03:15, Pavel Begunkov wrote:
> If the id and user/creds match, return an existing io_wq if we can safely
> grab a reference to it.

Missed the outdated comment. Apparently, it's too late for continue with it today.

>
> Reported-by: Jens Axboe <axboe@xxxxxxxxx>
> Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
> ---
> fs/io-wq.c | 8 ++++++++
> fs/io-wq.h | 1 +
> 2 files changed, 9 insertions(+)
>
> diff --git a/fs/io-wq.c b/fs/io-wq.c
> index b45d585cdcc8..ee49e8852d39 100644
> --- a/fs/io-wq.c
> +++ b/fs/io-wq.c
> @@ -1110,6 +1110,14 @@ struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data)
> return ERR_PTR(ret);
> }
>
> +bool io_wq_get(struct io_wq *wq, struct io_wq_data *data)
> +{
> + if (data->get_work != wq->get_work || data->put_work != wq->put_work)
> + return false;
> +
> + return refcount_inc_not_zero(&wq->use_refs);
> +}
> +
> static bool io_wq_worker_wake(struct io_worker *worker, void *data)
> {
> wake_up_process(worker->task);
> diff --git a/fs/io-wq.h b/fs/io-wq.h
> index 167316ad447e..c42602c58c56 100644
> --- a/fs/io-wq.h
> +++ b/fs/io-wq.h
> @@ -99,6 +99,7 @@ struct io_wq_data {
> };
>
> struct io_wq *io_wq_create(unsigned bounded, struct io_wq_data *data);
> +bool io_wq_get(struct io_wq *wq, struct io_wq_data *data);
> void io_wq_destroy(struct io_wq *wq);
>
> void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work);
>

--
Pavel Begunkov

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