From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752184AbdFNO0w (ORCPT ); Wed, 14 Jun 2017 10:26:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:37428 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751065AbdFNO0u (ORCPT ); Wed, 14 Jun 2017 10:26:50 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B36C219A8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=jaegeuk@kernel.org Date: Wed, 14 Jun 2017 07:26:48 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [PATCH] f2fs: fix ref of discard command Message-ID: <20170614142648.GA74571@jaegeuk-macbookpro.roam.corp.google.com> References: <20170612030449.79290-1-jaegeuk@kernel.org> <54b5aaad-1674-8d76-c489-d5eee6ef7f26@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <54b5aaad-1674-8d76-c489-d5eee6ef7f26@huawei.com> User-Agent: Mutt/1.8.2 (2017-04-18) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/12, Chao Yu wrote: > Hi Jaegeuk, > > On 2017/6/12 11:04, Jaegeuk Kim wrote: > > This patch resolves kernel panic for xfstests/081, caused by recent f2fs_bug_on > > > > f2fs: add f2fs_bug_on in __remove_discard_cmd > > > > Signed-off-by: Jaegeuk Kim > > --- > > fs/f2fs/segment.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > > index 86a0c1095939..a6d77388a806 100644 > > --- a/fs/f2fs/segment.c > > +++ b/fs/f2fs/segment.c > > @@ -1025,6 +1025,8 @@ static void __wait_discard_cmd(struct f2fs_sb_info *sbi, bool wait_cond) > > list_for_each_entry_safe(dc, tmp, wait_list, list) { > > if (!wait_cond || (dc->state == D_DONE && !dc->ref)) { > > wait_for_completion_io(&dc->wait); > > + if (dc->state == D_DONE && dc->ref) > > + dc->ref--; > > Should set dc->ref to 0 to avoid panic once we add other referrers? Sorry, could you please explain this in more detail? Thanks, > > Thanks, > > > __remove_discard_cmd(sbi, dc); > > } else { > > dc->ref++; > >