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Date:   Tue, 13 Jun 2023 23:23:25 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     David Howells <dhowells@redhat.com>
Cc:     Jens Axboe <axboe@kernel.dk>, David Hildenbrand <david@redhat.com>,
        kernel test robot <oliver.sang@intel.com>,
        Christoph Hellwig <hch@infradead.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Matthew Wilcox <willy@infradead.org>, Jan Kara <jack@suse.cz>,
        Jeff Layton <jlayton@kernel.org>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Hillf Danton <hdanton@sina.com>,
        Christian Brauner <brauner@kernel.org>,
        Lorenzo Stoakes <lstoakes@gmail.com>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-mm@kvack.org, oe-lkp@lists.linux.dev, lkp@intel.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] block: Fix dio_cleanup() to advance the head index
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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@lst.de>