From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794496287; b=U4BQWeLjjMn+KM5n5aCQFGiZ819UHM2a5bKpRo7JovpJ0ZRnVXIsf+BUB74n83qxgV6V tnX2zyaeIYZDQCU8lj7MnYUFfypx23SYAhFL9SZjmYc/pv/rZFLBGfkM8l0oP31HqHj8v xOH0JH0LnC5BmCGiOJi9HOiSXQwSZOdFFIHVe4Nl+xl+g6kD8Hp404vyJaM/3OsJuUP2n uA4CyAWjLHeWiX30EGqpjcmypusIAAdVq0Fxn5c10rPi2PnjveGvlvpTVdHwX+YFI1jgh yhgo5pxJUlNKrgTefcdjN1ec4CsEYoRM61scRo7mb/J5cRxbiJlNjwu6WOq9hAxPIiw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794496287; h=Received:DKIM-Signature:Date:Message-ID:From:To:Cc:Subject: In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=pOPUMS1h+yW9+Q5c6aClYkFvTD4eoG+32Raw8LpRQxc=; b=fHt40/vJxCfrCuNqLEdbYdXrosNUeWsmwlO1bXaX6mGBO1jAaUXO3ZAsVsNgXn2lD4Gj j9CBFiFV1a/nUB+Bz1hM3jgMqSnt02TLxohjETp1NCqETGRyMeZpvnqV/gezXmWkxikXd DscxS5EFsE95xg0vvyTcfs01pqY9tRrnJ3sWeMjuED+Z2L0KcqbmiK+nZa1OE6K+KBBMa ol9X6EkgWd9r0srfWsCDrWuAr6pKwfUMkr0MvoDb3glYHSVyphpN4MfU9FkwpJ3H783Hy WggjLqBJAxjgD8mUlEnM50swEZhgAmDlCAVgW7xVG2Xdzncjn36ICedNNVOqXLk7ljQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=JSAUGzyE; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B1843606A323; Thu, 12 Nov 2026 15:11:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=JSAUGzyE Received: by smtp.kernel.org (Postfix) with ESMTPSA id 665EB1F00A05; Thu, 12 Nov 2026 15:11:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794496287; bh=pOPUMS1h+yW9+Q5c6aClYkFvTD4eoG+32Raw8LpRQxc=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=JSAUGzyE7QbNMXTzQkx3wbfn1l6eP4DyrrbcIGYYG73188OznI9AFrCfXf2WpaLXs beGesy/cnPPXqaHEDO4586sbHZyiX4NKky7+fXZ4gbQ9f1TTIPk10L5TBSUxnnouFi nWrT3IFhNL1NG8NfYlhvb3sYc591FkhDPoVsqfUVBUtx6SlKYoGZ3StwcW8xRK/3Qu 9kk6inbYUUbdpvnWZNaww3tHbbNWd+mAhjLOWt/CwRePwxmr2rgHAAnvT/R85eL7rq 4PgmAuJjIC8j4FbYTZjLv9m3zVKwNA+58CgZEFXkz4U4Wq8zVPL3M38pLito2Lz9+t e8HROA+MZJ8MQ== Date: Thu, 12 Nov 2026 05:11:26 -1000 Message-ID: <07d063ef8ebcfc7f4e05c7318a423728@kernel.org> From: Tejun Heo To: Krystian Kaniewski Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Ian Kent , Danilo Krummrich , Johan Hovold , Len Brown , Pavel Machek , Jens Axboe , Alexander Viro , Christian Brauner , Jan Kara , driver-core@lists.linux.dev, linux-pm@vger.kernel.org, autofs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+002fb7b2d0bc53bf7e75@syzkaller.appspotmail.com Subject: Re: [PATCH v3 1/2] kernfs, sysfs: add SYSFS_NO_SPLICE to refuse splice on writable opens In-Reply-To: References: X-Mailing-List: driver-core@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hello, Krystian. On Thu, Nov 12, 2026 at 03:17:01PM +0100, Krystian Kaniewski wrote: > Read-only opens keep splice support because they cannot reach > ->write(). The patch looks fine to me, but I'm not sure whether the read-only exemption is necessary. Is it addressing an actual problem? busybox, for example, just falls back to regular reads when sendfile() fails with -EINVAL, and refusing splice reads on read-write opens while allowing them on read-only ones seems more confusing than anything else. Would it be simpler to refuse splice for all opens of the file? Thanks. -- tejun