Re: [PATCH 03/17] splice: Add a func to do a splice from an O_DIRECT file without ITER_PIPE

From: David Howells <dhowells@redhat.com>
To: unlisted-recipients:; (no To-header on input)
Cc: dhowells@redhat.com, Steve French <smfrench@gmail.com>,
	Jens Axboe <axboe@kernel.dk>, Al Viro <viro@zeniv.linux.org.uk>,
	Shyam Prasad N <nspmangalore@gmail.com>,
	Rohith Surabattula <rohiths.msft@gmail.com>,
	Tom Talpey <tom@talpey.com>, Stefan Metzmacher <metze@samba.org>,
	Christoph Hellwig <hch@infradead.org>,
	Matthew Wilcox <willy@infradead.org>,
	Jeff Layton <jlayton@kernel.org>,
	linux-cifs@vger.kernel.org, linux-block@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org,
	syzbot+a440341a59e3b7142895@syzkaller.appspotmail.com,
	Christoph Hellwig <hch@lst.de>,
	David Hildenbrand <david@redhat.com>,
	John Hubbard <jhubbard@nvidia.com>
Subject: Re: [PATCH 03/17] splice: Add a func to do a splice from an O_DIRECT file without ITER_PIPE
Date: Fri, 17 Feb 2023 09:00:01 +0000	[thread overview]
Message-ID: <4125892.1676624401@warthog.procyon.org.uk> (raw)
In-Reply-To: <20230216214745.3985496-4-dhowells@redhat.com>

David Howells <dhowells@redhat.com> wrote:

> diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
> index 6cb65df3e3ba..d2c3f16cf6b1 100644
> --- a/include/linux/pipe_fs_i.h
> +++ b/include/linux/pipe_fs_i.h
> @@ -156,6 +156,26 @@ static inline bool pipe_full(unsigned int head, unsigned int tail,
>  	return pipe_occupancy(head, tail) >= limit;
>  }
>  
> +/**
> + * pipe_buf - Return the pipe buffer for the specified slot in the pipe ring
> + * @pipe: The pipe to access
> + * @slot: The slot of interest
> + */
> +static inline struct pipe_buffer *pipe_buf(const struct pipe_inode_info *pipe,
> +					   unsigned int slot)
> +{
> +	return &pipe->bufs[slot & (pipe->ring_size - 1)];
> +}
> +
> +/**
> + * pipe_head_buf - Return the pipe buffer at the head of the pipe ring
> + * @pipe: The pipe to access
> + */
> +static inline struct pipe_buffer *pipe_head_buf(const struct pipe_inode_info *pipe)
> +{
> +	return pipe_buf(pipe, pipe->head);
> +}
> +
>  /**
>   * pipe_buf_get - get a reference to a pipe_buffer
>   * @pipe:	the pipe that the buffer belongs to
> diff --git a/lib/iov_iter.c b/lib/iov_iter.c
> index f9a3ff37ecd1..47c484551c59 100644
> --- a/lib/iov_iter.c
> +++ b/lib/iov_iter.c
> @@ -186,12 +186,6 @@ static int copyin(void *to, const void __user *from, size_t n)
>  	return res;
>  }
>  
> -static inline struct pipe_buffer *pipe_buf(const struct pipe_inode_info *pipe,
> -					   unsigned int slot)
> -{
> -	return &pipe->bufs[slot & (pipe->ring_size - 1)];
> -}
> -
>  #ifdef PIPE_PARANOIA
>  static bool sanity(const struct iov_iter *i)
>  {

This needs moving to the previous patch, but no code change overall.

David