[Devel] [PATCH VZ9 3/3] drivers/md/ploop: decrease inflight number after pio endio

[Pavel Tikhomirov]

On 7/15/25 22:20, Andrey Zhadchenko wrote:
> We do not increase inflight number when we chain pios, so we should
> decrease inflight only after all chained pios are also completed,
> e.g. pio->remaining is zero, and file is flushed if needed

I see that ploop_inc_nr_inflight and ploop_dec_nr_inflight are designed 
the way that only if ploop_inc_nr_inflight really happened on pio, then 
ploop_dec_nr_inflight on it will decrement the inflight reference.

E.g. chained splited pios should just have pio->ref_index == 
PLOOP_REF_INDEX_INVALID, if there was no ploop_inc_nr_inflight on them, 
and on "dec" nothing will happen.

So I'm not sure if this patch is really needed.

> 
> https://virtuozzo.atlassian.net/browse/VSTOR-108540
> Signed-off-by: Andrey Zhadchenko <andrey.zhadchenko at virtuozzo.com>
> ---
>   drivers/md/dm-ploop-map.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
> index 7604b3c8d644..9f2e55df2904 100644
> --- a/drivers/md/dm-ploop-map.c
> +++ b/drivers/md/dm-ploop-map.c
> @@ -214,6 +214,8 @@ static void ploop_prq_endio(struct pio *pio, void *prq_ptr,
>   	dm_complete_request(rq, bi_status);
>   }
>   
> +static void ploop_dec_nr_inflight(struct ploop *ploop, struct pio *pio);
> +
>   static void ploop_wrkr_pio_endio(struct pio *pio)
>   {
>   	ploop_endio_t endio_cb = pio->endio_cb;
> @@ -223,6 +225,8 @@ static void ploop_wrkr_pio_endio(struct pio *pio)
>   
>   	file = ploop_top_delta(pio->ploop)->file;
>   	vfs_fsync(file, 1);
> +
> +	ploop_dec_nr_inflight(pio->ploop, pio);
>   	endio_cb(pio, endio_cb_data, pio->bi_status);
>   	if (free_on_endio) {
>   		ploop_free_pio(pio->ploop, pio);
> @@ -245,6 +249,7 @@ static void ploop_do_pio_endio(struct pio *pio)
>   		return;
>   	}
>   
> +	ploop_dec_nr_inflight(pio->ploop, pio);
>   	endio_cb(pio, endio_cb_data, pio->bi_status);
>   
>   	if (free_on_endio)
> @@ -2695,7 +2700,6 @@ static void ploop_handle_cleanup(struct ploop *ploop, struct pio *pio)
>   		ploop_discard_index_pio_end(ploop, pio);
>   
>   	ploop_unlink_completed_pio(ploop, pio);
> -	ploop_dec_nr_inflight(ploop, pio);
>   }
>   
>   /*

-- 
Best regards, Pavel Tikhomirov
Senior Software Developer, Virtuozzo.