Date:   Mon, 13 Feb 2023 06:44:23 -0800
From:   Christoph Hellwig <hch@infradead.org>
To:     David Howells <dhowells@redhat.com>
Cc:     Christoph Hellwig <hch@infradead.org>,
        Jens Axboe <axboe@kernel.dk>,
        Al Viro <viro@zeniv.linux.org.uk>,
        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>
Subject: Re: [PATCH v13 03/12] splice: Do splice read from a buffered file
 without using ITER_PIPE
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On Mon, Feb 13, 2023 at 11:15:37AM +0000, David Howells wrote:
> I'm not sure I want ki_flags setting from f_iocb_flags I should've said.  I'm
> not sure how the IOCB_* flags that I import from there will affect the
> operation of the synchronous read splice.

The same way as they did in the old ITER_PIPE based
generic_file_splice_read that uses init_sync_kiocb?  And if there's any
questions about them we need to do a deep audit.

> IOCB_NOWAIT, for example, or, for

I'd expect a set IOCB_NOWAIT to make the function return -EAGAIN
when it has to block.

> that matter, IOCB_APPEND.

IOCB_APPEND has no effect on reads of any kind.