[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20201118151806.GA25804@infradead.org>
Date: Wed, 18 Nov 2020 15:18:06 +0000
From: Christoph Hellwig <hch@...radead.org>
To: Michal Kubecek <mkubecek@...e.cz>
Cc: Alexander Viro <viro@...iv.linux.org.uk>,
linux-fsdevel@...r.kernel.org, Jens Axboe <axboe@...nel.dk>,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] eventfd: convert to ->write_iter()
On Wed, Nov 18, 2020 at 10:19:17AM +0100, Michal Kubecek wrote:
> While eventfd ->read() callback was replaced by ->read_iter() recently,
> it still provides ->write() for writes. Since commit 4d03e3cc5982 ("fs:
> don't allow kernel reads and writes without iter ops"), this prevents
> kernel_write() to be used for eventfd and with set_fs() removal,
> ->write() cannot be easily called directly with a kernel buffer.
>
> According to eventfd(2), eventfd descriptors are supposed to be (also)
> used by kernel to notify userspace applications of events which now
> requires ->write_iter() op to be available (and ->write() not to be).
> Therefore convert eventfd_write() to ->write_iter() semantics. This
> patch also cleans up the code in a similar way as commit 12aceb89b0bc
> ("eventfd: convert to f_op->read_iter()") did in read_iter().
A far as I can tell we don't have an in-tree user that writes to an
eventfd. We can merge something like this once there is a user.
Powered by blists - more mailing lists