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 X-Spam-Level: X-Spam-Status: No, score=-2.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 845BEC6778C for ; Tue, 3 Jul 2018 04:11:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 36E8524D04 for ; Tue, 3 Jul 2018 04:11:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 36E8524D04 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753912AbeGCELl (ORCPT ); Tue, 3 Jul 2018 00:11:41 -0400 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:44246 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751760AbeGCELj (ORCPT ); Tue, 3 Jul 2018 00:11:39 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04400;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0T3scjyw_1530591079; Received: from e19h19392.et15sqa.tbsite.net(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0T3scjyw_1530591079) by smtp.aliyun-inc.com(127.0.0.1); Tue, 03 Jul 2018 12:11:27 +0800 From: Yang Shi To: mgorman@techsingularity.net, tytso@mit.edu, adilger.kernel@dilger.ca, darrick.wong@oracle.com, dchinner@redhat.com, akpm@linux-foundation.org Cc: yang.shi@linux.alibaba.com, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 2/2] fs: xfs: use BUG_ON if writepage call comes from direct reclaim Date: Tue, 3 Jul 2018 12:11:19 +0800 Message-Id: <1530591079-33813-2-git-send-email-yang.shi@linux.alibaba.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1530591079-33813-1-git-send-email-yang.shi@linux.alibaba.com> References: <1530591079-33813-1-git-send-email-yang.shi@linux.alibaba.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org direct reclaim doesn't write out filesystem page, only kswapd could do this. So, if it is called from direct relaim, it is definitely a bug. And, Mel Gorman mentioned "Ultimately, this will be a BUG_ON." in commit 94054fa3fca1fd78db02cb3d68d5627120f0a1d4 ("xfs: warn if direct reclaim tries to writeback pages"), It has been many years since that commit, so it should be safe to elevate WARN_ON to BUG_ON now. Cc: Mel Gorman Cc: Darrick J. Wong Cc: Dave Chinner Signed-off-by: Yang Shi --- fs/xfs/xfs_aops.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c index 8eb3ba3..7efc2d2 100644 --- a/fs/xfs/xfs_aops.c +++ b/fs/xfs/xfs_aops.c @@ -1080,11 +1080,9 @@ static inline int xfs_bio_add_buffer(struct bio *bio, struct buffer_head *bh) * allow reclaim from kswapd as the stack usage there is relatively low. * * This should never happen except in the case of a VM regression so - * warn about it. + * BUG about it. */ - if (WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == - PF_MEMALLOC)) - goto redirty; + BUG_ON((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == PF_MEMALLOC); /* * Given that we do not allow direct reclaim to call us, we should -- 1.8.3.1