From: Greg KH <gregkh@linuxfoundation.org>
To: Ryosuke Yasuoka <ryasuoka@redhat.com>
Cc: arnd@arndb.de, ojeda@kernel.org, alex.gaynor@gmail.com,
boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com,
lossin@kernel.org, a.hindborg@kernel.org, aliceryhl@google.com,
tmgross@umich.edu, dakr@kernel.org, viro@zeniv.linux.org.uk,
brauner@kernel.org, jack@suse.cz, rust-for-linux@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH rust-next v2 0/3] rust: miscdevice: add llseek support
Date: Thu, 16 Oct 2025 13:24:12 +0200 [thread overview]
Message-ID: <2025101610-detention-dangle-cef6@gregkh> (raw)
In-Reply-To: <aPDGxz04OQgzRQqL@zeus>
On Thu, Oct 16, 2025 at 07:19:51PM +0900, Ryosuke Yasuoka wrote:
> On Wed, Oct 15, 2025 at 07:40:12AM +0200, Greg KH wrote:
> > On Wed, Oct 15, 2025 at 01:02:40PM +0900, Ryosuke Yasuoka wrote:
> > > Hi all,
> > >
> > > This patch series add support for the llseek file operation to misc
> > > devices written in Rust.
> >
> > Cool, but what miscdevice driver needs llseek support? Do you have a
> > real user for this that we can see as well?
>
> Currently no. Because lseek is one of fundamental functions for device
> driver, I think it's valuable to add support. I believe we'll have real
> users based on read, write, and this lseek support.
Char devices that use lseek are "odd", don't you agree? There are no
such current users under drivers/misc/ and only a rare few under
drivers/char/ (the huge user of that is mem.c but we aren't going to be
reimplementing that in rust any time soon...)
So without a real user of this api, I suggest we hold-off on adding it.
Let's not add it until someone comes up with a very valid reason for it.
thanks,
greg k-h
next prev parent reply other threads:[~2025-10-16 11:24 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-15 4:02 [PATCH rust-next v2 0/3] rust: miscdevice: add llseek support Ryosuke Yasuoka
2025-10-15 4:02 ` [PATCH rust-next v2 1/3] rust: fs: add pos/pos_mut methods for LocalFile struct Ryosuke Yasuoka
2025-10-15 4:02 ` [PATCH rust-next v2 2/3] rust: miscdevice: add llseek support Ryosuke Yasuoka
2025-10-15 4:02 ` [PATCH rust-next v2 3/3] rust: samples: miscdevice: add lseek samples Ryosuke Yasuoka
2025-10-15 5:40 ` [PATCH rust-next v2 0/3] rust: miscdevice: add llseek support Greg KH
2025-10-16 10:19 ` Ryosuke Yasuoka
2025-10-16 11:24 ` Greg KH [this message]
2025-10-16 14:39 ` Ryosuke Yasuoka
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