From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751529AbeDFIHT (ORCPT ); Fri, 6 Apr 2018 04:07:19 -0400 Received: from mx2.suse.de ([195.135.220.15]:43563 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751089AbeDFIHR (ORCPT ); Fri, 6 Apr 2018 04:07:17 -0400 Date: Fri, 6 Apr 2018 10:07:14 +0200 From: Michal Hocko To: Greg Thelen Cc: Wang Long , Andrew Morton , Johannes Weiner , Tejun Heo , npiggin@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH] writeback: safer lock nesting Message-ID: <20180406080714.GG8286@dhcp22.suse.cz> References: <2cb713cd-0b9b-594c-31db-b4582f8ba822@meituan.com> <20180406080324.160306-1-gthelen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180406080324.160306-1-gthelen@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 06-04-18 01:03:24, Greg Thelen wrote: [...] > diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c > index d4d04fee568a..d51bae5a53e2 100644 > --- a/fs/fs-writeback.c > +++ b/fs/fs-writeback.c > @@ -746,10 +746,11 @@ int inode_congested(struct inode *inode, int cong_bits) > if (inode && inode_to_wb_is_valid(inode)) { > struct bdi_writeback *wb; > bool locked, congested; > + unsigned long flags; > > - wb = unlocked_inode_to_wb_begin(inode, &locked); > + wb = unlocked_inode_to_wb_begin(inode, &locked, &flags); Wouldn't it be better to have a cookie (struct) rather than 2 parameters and let unlocked_inode_to_wb_end DTRT? > congested = wb_congested(wb, cong_bits); > - unlocked_inode_to_wb_end(inode, locked); > + unlocked_inode_to_wb_end(inode, locked, flags); > return congested; > } -- Michal Hocko SUSE Labs