From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7D773C433FE for ; Wed, 20 Oct 2021 12:32:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 620B461355 for ; Wed, 20 Oct 2021 12:32:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230242AbhJTMfF (ORCPT ); Wed, 20 Oct 2021 08:35:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:51970 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230168AbhJTMfF (ORCPT ); Wed, 20 Oct 2021 08:35:05 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 37C7A60F57; Wed, 20 Oct 2021 12:32:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1634733170; bh=dFn+jTdLLyp2tS25P2DzRAmAECFjBC+RanyBlBG5KVY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ym7WPF0PcD+sIJ2/NlMH8sthMlViUab7AZYeota5uQ9f/JJN6hDxWvkua3nTaELL3 eTcdYDpQPpnPO2Uiw7h06NwnXuOu0wJEkeYgPhNLPUAZZ5eaVNF71CsoQBUdE2FPBQ pzZbZ2gnQx535QAMD5i94WPVLryiMzfM6+PMVcYA= Date: Wed, 20 Oct 2021 14:32:48 +0200 From: Greg KH To: Anand Jain Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux-btrfs@vger.kernel.org, Josef Bacik , Filipe Manana Subject: Re: [PATCH stable-4.14.y] btrfs: always wait on ordered extents at fsync time Message-ID: References: <4fb0d755f4265d71b2a0d314232e53b22067fb0b.1634624427.git.anand.jain@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4fb0d755f4265d71b2a0d314232e53b22067fb0b.1634624427.git.anand.jain@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Tue, Oct 19, 2021 at 06:38:20PM +0800, Anand Jain wrote: > From: Josef Bacik > > Commit b5e6c3e170b77025b5f6174258c7ad71eed2d4de upstream. > > There's a priority inversion that exists currently with btrfs fsync. In > some cases we will collect outstanding ordered extents onto a list and > only wait on them at the very last second. However this "very last > second" falls inside of a transaction handle, so if we are in a lower > priority cgroup we can end up holding the transaction open for longer > than needed, so if a high priority cgroup is also trying to fsync() > it'll see latency. > > Signed-off-by: Josef Bacik > Reviewed-by: Filipe Manana > Signed-off-by: David Sterba > Signed-off-by: Anand Jain > --- > fs/btrfs/file.c | 56 ++++--------------------------------------------- > 1 file changed, 4 insertions(+), 52 deletions(-) Now applied, thanks. greg k-h