From: Ming Lei <ming.lei@redhat.com>
To: David Howells <dhowells@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>, Al Viro <viro@zeniv.linux.org.uk>,
Christoph Hellwig <hch@infradead.org>,
Matthew Wilcox <willy@infradead.org>, 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>,
Hillf Danton <hdanton@sina.com>,
linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Christoph Hellwig <hch@lst.de>,
John Hubbard <jhubbard@nvidia.com>,
ming.lei@redhat.com
Subject: Re: [PATCH v14 08/17] splice: Do splice read from a file without using ITER_PIPE
Date: Fri, 17 Feb 2023 16:22:14 +0800 [thread overview]
Message-ID: <Y+85Ni9CH/7ajQga@T590> (raw)
In-Reply-To: <20230214171330.2722188-9-dhowells@redhat.com>
On Tue, Feb 14, 2023 at 05:13:21PM +0000, David Howells wrote:
> Make generic_file_splice_read() use filemap_splice_read() and
> direct_splice_read() rather than using an ITER_PIPE and call_read_iter().
>
> With this, ITER_PIPE is no longer used.
>
> Signed-off-by: David Howells <dhowells@redhat.com>
> cc: Jens Axboe <axboe@kernel.dk>
> cc: Christoph Hellwig <hch@lst.de>
> cc: Al Viro <viro@zeniv.linux.org.uk>
> cc: David Hildenbrand <david@redhat.com>
> cc: John Hubbard <jhubbard@nvidia.com>
> cc: linux-mm@kvack.org
> cc: linux-block@vger.kernel.org
> cc: linux-fsdevel@vger.kernel.org
> ---
>
> Notes:
> ver #14)
> - Split out filemap_splice_read() into a separate patch.
>
> fs/splice.c | 30 +++++++-----------------------
> 1 file changed, 7 insertions(+), 23 deletions(-)
>
> diff --git a/fs/splice.c b/fs/splice.c
> index 4c6332854b63..a93478338cec 100644
> --- a/fs/splice.c
> +++ b/fs/splice.c
> @@ -391,29 +391,13 @@ ssize_t generic_file_splice_read(struct file *in, loff_t *ppos,
> struct pipe_inode_info *pipe, size_t len,
> unsigned int flags)
> {
> - struct iov_iter to;
> - struct kiocb kiocb;
> - int ret;
> -
> - iov_iter_pipe(&to, ITER_DEST, pipe, len);
> - init_sync_kiocb(&kiocb, in);
> - kiocb.ki_pos = *ppos;
> - ret = call_read_iter(in, &kiocb, &to);
> - if (ret > 0) {
> - *ppos = kiocb.ki_pos;
> - file_accessed(in);
> - } else if (ret < 0) {
> - /* free what was emitted */
> - pipe_discard_from(pipe, to.start_head);
> - /*
> - * callers of ->splice_read() expect -EAGAIN on
> - * "can't put anything in there", rather than -EFAULT.
> - */
> - if (ret == -EFAULT)
> - ret = -EAGAIN;
> - }
> -
> - return ret;
> + if (unlikely(*ppos >= file_inode(in)->i_sb->s_maxbytes))
> + return 0;
> + if (unlikely(!len))
> + return 0;
> + if (in->f_flags & O_DIRECT)
> + return direct_splice_read(in, ppos, pipe, len, flags);
Hello David,
I have one question, for dio, pages need to map to userspace
memory, but direct_splice_read() just allocates pages and not
see when the user mapping is setup, can you give one hint?
Thanks,
Ming
next prev parent reply other threads:[~2023-02-17 8:23 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-14 17:13 [PATCH v14 00/17] iov_iter: Improve page extraction (pin or just list) David Howells
2023-02-14 17:13 ` [PATCH v14 01/17] mm: Pass info, not iter, into filemap_get_pages() David Howells
2023-02-14 17:13 ` [PATCH v14 02/17] splice: Add a func to do a splice from a buffered file without ITER_PIPE David Howells
2023-02-18 2:41 ` Ming Lei
2023-02-18 9:25 ` David Howells
2023-02-14 17:13 ` [PATCH v14 03/17] splice: Add a func to do a splice from an O_DIRECT " David Howells
2023-02-14 17:13 ` [PATCH v14 04/17] shmem: Implement splice-read David Howells
2023-02-14 17:13 ` [PATCH v14 05/17] overlayfs: " David Howells
2023-02-15 14:21 ` Miklos Szeredi
2023-02-15 15:03 ` David Howells
2023-02-15 15:32 ` Miklos Szeredi
2023-02-15 15:40 ` [PATCH v15 " David Howells
2023-02-15 15:50 ` Miklos Szeredi
2023-02-15 15:53 ` Matthew Wilcox
2023-02-15 16:38 ` Christoph Hellwig
2023-02-15 16:40 ` Miklos Szeredi
2023-02-15 15:58 ` David Howells
2023-02-14 17:13 ` [PATCH v14 06/17] coda: " David Howells
2023-02-14 18:04 ` Jan Harkes
2023-02-14 17:13 ` [PATCH v14 07/17] tty, proc, kernfs, random: Use direct_splice_read() David Howells
2023-02-14 17:13 ` [PATCH v14 08/17] splice: Do splice read from a file without using ITER_PIPE David Howells
2023-02-17 8:22 ` Ming Lei [this message]
2023-02-17 9:18 ` Ming Lei
2023-02-17 20:39 ` Alexander Egorenkov
2023-02-17 20:59 ` egorenar
2023-02-17 21:24 ` David Howells
2023-02-17 21:16 ` David Howells
2023-02-17 21:47 ` David Howells
2023-02-18 8:29 ` Alexander Egorenkov
2023-02-18 9:18 ` David Howells
2023-02-14 17:13 ` [PATCH v14 09/17] iov_iter: Kill ITER_PIPE David Howells
2023-02-14 17:13 ` [PATCH v14 10/17] iov_iter: Define flags to qualify page extraction David Howells
2023-02-14 17:13 ` [PATCH v14 11/17] iov_iter: Add a function to extract a page list from an iterator David Howells
2023-02-14 17:13 ` [PATCH v14 12/17] iomap: Don't get an reference on ZERO_PAGE for direct I/O block zeroing David Howells
2023-02-14 17:13 ` [PATCH v14 13/17] block: Fix bio_flagged() so that gcc can better optimise it David Howells
2023-02-14 17:13 ` [PATCH v14 14/17] block: Replace BIO_NO_PAGE_REF with BIO_PAGE_REFFED with inverted logic David Howells
2023-02-14 17:13 ` [PATCH v14 15/17] block: Add BIO_PAGE_PINNED and associated infrastructure David Howells
2023-02-14 17:13 ` [PATCH v14 16/17] block: Convert bio_iov_iter_get_pages to use iov_iter_extract_pages David Howells
2023-02-14 17:13 ` [PATCH v14 17/17] block: convert bio_map_user_iov " David Howells
2023-02-14 22:56 ` [PATCH v14 00/17] iov_iter: Improve page extraction (pin or just list) David Howells
2023-02-14 23:05 ` Jens Axboe
2023-02-15 8:07 ` David Howells
2023-02-15 14:23 ` Christoph Hellwig
2023-02-15 14:38 ` Christoph Hellwig
2023-02-15 15:43 ` David Howells
2023-02-15 8:20 ` David Howells
2023-02-14 23:01 ` David Howells
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Y+85Ni9CH/7ajQga@T590 \
--to=ming.lei@redhat.com \
--cc=axboe@kernel.dk \
--cc=david@redhat.com \
--cc=dhowells@redhat.com \
--cc=hch@infradead.org \
--cc=hch@lst.de \
--cc=hdanton@sina.com \
--cc=jack@suse.cz \
--cc=jgg@nvidia.com \
--cc=jhubbard@nvidia.com \
--cc=jlayton@kernel.org \
--cc=linux-block@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=logang@deltatee.com \
--cc=viro@zeniv.linux.org.uk \
--cc=willy@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).