From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CAB9A263F54; Tue, 25 Nov 2025 09:18:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764062319; cv=none; b=o3d70eGqDmJ/qspVfoSiqOrMneSs6LqGGyIAhRoK5NV1GvEVbT9r/qX8s8Ju8bt/WmriUFOgshE53gQH1PufGvQGq2NJhHkfOQtHsmyE+ktpjlsYfOLliFocm7oyfQXXqc85toCHL91A8g3ybVSUppzHuWZGqFlipbpS/XDRJ8Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764062319; c=relaxed/simple; bh=U9iYrYsglLkG8TnBDbI9yrwUWiI8plUWD8Oh3w7r1lw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Pug8qhPlHqLSY3p2qkdJb/rZI/H3zF1g2ZKKsdS++5sflR683fnaXiQ+5Z8mcpD1+7QO94sTfFlrY+bdFBLzsctoiciHztP0csErL/NUcQxKibqkJL4I3XH9V6ZxaO87wMGVRT9Ci3Mt+bTPhkaLNN5lMVTsa78YPQzsJiImAeI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=sctjiYa/; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="sctjiYa/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 62470C4CEF1; Tue, 25 Nov 2025 09:18:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1764062318; bh=U9iYrYsglLkG8TnBDbI9yrwUWiI8plUWD8Oh3w7r1lw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=sctjiYa/DATKoaFc3hWyAe155qdsmeZ0LOX1jyiLgNBS5DiZw+4snbDy8w3moMIlw qD25hlXOxRpAQw7ks/SOJcVlNOSn2alp+vSe+skncJ9fnv47blkRv/OO1HEnfaLieL Pdfx8nRHNYcPX7bTnyTH+HvgbdCM1/yJVva5Dr3pvCvteXBjjd4kwFh15WUdPqWtXT KDE5JgmgqxTmE7mMVxru75iVNEw+PlMkuj4dLF4KAWCHoOTXoPZcis8CK0XFDtFgFD fKp2aeOAxiijY6s+DoOEPPdvCjJNOF89n2osZI1BVl6VydJ00KKVQTPicDc0+hBj82 /u0YfbHQEuJ6g== Date: Tue, 25 Nov 2025 10:18:32 +0100 From: Christian Brauner To: Christoph Hellwig Cc: Al Viro , David Sterba , Jan Kara , Mike Marshall , Martin Brandenburg , Carlos Maiolino , Stefan Roesch , Jeff Layton , linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, gfs2@lists.linux.dev, io-uring@vger.kernel.org, devel@lists.orangefs.org, linux-unionfs@vger.kernel.org, linux-mtd@lists.infradead.org, linux-xfs@vger.kernel.org, linux-nfs@vger.kernel.org Subject: Re: re-enable IOCB_NOWAIT writes to files v2 Message-ID: <20251125-loten-fabuliert-c0fb6b195b53@brauner> References: <20251120064859.2911749-1-hch@lst.de> 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=utf-8 Content-Disposition: inline In-Reply-To: <20251120064859.2911749-1-hch@lst.de> On Thu, Nov 20, 2025 at 07:47:21AM +0100, Christoph Hellwig wrote: > Hi all, > > commit 66fa3cedf16a ("fs: Add async write file modification handling.") > effectively disabled IOCB_NOWAIT writes as timestamp updates currently > always require blocking, and the modern timestamp resolution means we > always update timestamps. This leads to a lot of context switches from > applications using io_uring to submit file writes, making it often worse > than using the legacy aio code that is not using IOCB_NOWAIT. > > This series allows non-blocking updates for lazytime if the file system > supports it, and adds that support for XFS. > > It also fixes the layering bypass in btrfs when updating timestamps on > device files for devices removed from btrfs usage, and FMODE_NOCMTIME > handling in the VFS now that nfsd started using it. Note that I'm still > not sure that nfsd usage is fully correct for all file systems, as only > XFS explicitly supports FMODE_NOCMTIME, but at least the generic code > does the right thing now. It's a bit too close to the merge window for my taste and we have about 17 pull request topics for this cycle already. So I'll take this for vfs-6.20.iomap. As usual I'll create that branch now so that the patches don't get lost and will rebase once v6.19-rc1 is out.