Re: [PATCH] block: Fix dio_cleanup() to advance the head index

[Christoph Hellwig]

On Tue, Jun 13, 2023 at 10:54:39PM +0100, David Howells wrote:
> --- a/fs/direct-io.c
> +++ b/fs/direct-io.c
> @@ -459,6 +459,7 @@ static inline void dio_cleanup(struct dio *dio, struct dio_submit *sdio)
>  	if (dio->is_pinned)
>  		unpin_user_pages(dio->pages + sdio->head,
>  				 sdio->tail - sdio->head);
> +	sdio->head = sdio->tail;

So looking at the original patch, it does:

-       while (sdio->head < sdio->tail)
-               put_page(dio->pages[sdio->head++]);
+       if (dio->is_pinned)
+               unpin_user_pages(dio->pages + sdio->head,
+                                sdio->tail - sdio->head);

so yes, we're this looks correct:

Reviewed-by: Christoph Hellwig <hch@xxxxxx>