Re: [PATCH v9 3/8] iomap: Don't get an reference on ZERO_PAGE for direct I/O block zeroing

From: John Hubbard <jhubbard@nvidia.com>
To: David Howells <dhowells@redhat.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Christoph Hellwig <hch@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>,
	Jens Axboe <axboe@kernel.dk>, "Jan Kara" <jack@suse.cz>,
	Jeff Layton <jlayton@kernel.org>,
	David Hildenbrand <david@redhat.com>,
	Jason Gunthorpe <jgg@nvidia.com>,
	Logan Gunthorpe <logang@deltatee.com>,
	<linux-fsdevel@vger.kernel.org>, <linux-block@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v9 3/8] iomap: Don't get an reference on ZERO_PAGE for direct I/O block zeroing
Date: Tue, 24 Jan 2023 11:25:16 -0800	[thread overview]
Message-ID: <dac764eb-ef21-4ec5-bcd8-102ca4d49f20@nvidia.com> (raw)
In-Reply-To: <20230124170108.1070389-4-dhowells@redhat.com>

On 1/24/23 09:01, David Howells wrote:
> ZERO_PAGE can't go away, no need to hold an extra reference.
> 
> Signed-off-by: David Howells <dhowells@redhat.com>
> Reviewed-by: David Hildenbrand <david@redhat.com>
> ---
>   fs/iomap/direct-io.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 

Reviewed-by: John Hubbard <jhubbard@nvidia.com>

thanks,
-- 
John Hubbard
NVIDIA

> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 9804714b1751..47db4ead1e74 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -202,7 +202,7 @@ static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio,
>   	bio->bi_private = dio;
>   	bio->bi_end_io = iomap_dio_bio_end_io;
>   
> -	get_page(page);
> +	bio_set_flag(bio, BIO_NO_PAGE_REF);
>   	__bio_add_page(bio, page, len, 0);
>   	iomap_dio_submit_bio(iter, dio, bio, pos);
>   }
>