From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1AB9E2D0614; Fri, 13 Feb 2026 07:21:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.133 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770967301; cv=none; b=Rkib0REFa19LCIOoefsoNVxD9RQDpdFg+D916i62LYDhvUKM7xej1LaT1DlQK6knTnBpQDte+Z93VbqahyJCTBT96xeocc3c/cEoEE0n4OT2TsvN+VYaXQHgksCQeYOxzrk9LAJCj+cnsgVxFPmGpg1Z9PCZNg2jzo8dMxxXuvo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770967301; c=relaxed/simple; bh=d58jNyFP4c6x62DKuHGytiRAbkeCTxY3dwORzpI699k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HhyExzikv+IHWyGH9ncnJSmpcK4lUr81mYZmU80/JQUA3hoLAVetJml9PT7+FtzXOg8UAW/bErhQ7M3VPhf0lK74WJYB3Tdk+2oJCPMz/Myg6v/xyLSTB7vaiMNPfVTvcDnR8mNY/6Kj4D1847X8wt203T8Mci+BiMpx3CkOgjo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=miQqrRKl; arc=none smtp.client-ip=198.137.202.133 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bombadil.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="miQqrRKl" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=w8XX0e+hf5Z2QUNXIEOROxGO64PWLl9iu8IzemUOXhs=; b=miQqrRKly9DqxAmRmrgTAxZ410 BdAj/alRPQftoUVJNcJcK1B5Tzw/ExAgpbwxVwNEY6PgMWjCXpRKEL8tU7N7m5LMApL8CxujedT0i 2qZygIOE8FJtfDFtfGb/5BP2FxA5T29oZAm65pOnFx9vPd4kHrXTJclqsZw6RVaOh9tdocmtPdbQj OC8o9EAX1QQh7j1S/GKUu/iZnGWXMWYQJNy5pbgIIvt2HF2sMib80NAeCJX/2l8CKGNoeuK1SG6mA 33WfVrJZN8wZVUqIgqRGISPiJSkzTQm0vk++aIJCjtc9ed/FwCUKMCXPzD7x2+MzsVS47MGc0YEKk q2mRHlUw==; Received: from hch by bombadil.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vqnUh-00000003674-0qU9; Fri, 13 Feb 2026 07:21:39 +0000 Date: Thu, 12 Feb 2026 23:21:39 -0800 From: Christoph Hellwig To: Pavel Begunkov Cc: Christoph Hellwig , Joanne Koong , axboe@kernel.dk, io-uring@vger.kernel.org, csander@purestorage.com, krisman@suse.de, bernd@bsbernd.com, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v1 03/11] io_uring/kbuf: add support for kernel-managed buffer rings Message-ID: References: <20260210002852.1394504-1-joannelkoong@gmail.com> <20260210002852.1394504-4-joannelkoong@gmail.com> <89c75fc1-2def-4681-a790-78b12b45478a@gmail.com> <1c657f67-0862-4e13-9c71-7217aeecef61@gmail.com> <809cd04b-007b-46c6-9418-161e757e0e80@gmail.com> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <809cd04b-007b-46c6-9418-161e757e0e80@gmail.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html On Thu, Feb 12, 2026 at 10:52:29AM +0000, Pavel Begunkov wrote: > > I'm arguing exactly against this. For my use case I need a setup > > where the kernel controls the allocation fully and guarantees user > > processes can only read the memory but never write to it. I'd love > > to be able to piggy back than onto your work. > > IORING_REGISTER_MEM_REGION supports both types of allocations. It can > have a new registration flag for read-only, and then you either make IORING_REGISTER_MEM_REGION seems to be all about cqs from both your commit message and the public documentation. I'm confused. > the bounce avoidance optional or reject binding fuse to unsupported > setups during init. Any arguments against that? I need to go over > Joanne's reply, but I don't see any contradiction in principal with > your use case. My use case is not about fuse, but good old block and file system I/O.