From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: Re: [PATCH] f2fs: fix wrong sum_page pointer in f2fs_gc Date: Fri, 14 Oct 2016 09:57:00 -0700 Message-ID: <20161014165700.GA67182@jaegeuk> References: <20161012232304.6667-1-jaegeuk@kernel.org> <20161013171421.GA6363@jaegeuk> <3ed5607f-0fe6-02cb-8c95-782913e65b5b@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bv5nD-0005JK-0L for linux-f2fs-devel@lists.sourceforge.net; Fri, 14 Oct 2016 16:57:11 +0000 Received: from mail.kernel.org ([198.145.29.136]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.76) id 1bv5nA-0002ns-Rf for linux-f2fs-devel@lists.sourceforge.net; Fri, 14 Oct 2016 16:57:10 +0000 Content-Disposition: inline In-Reply-To: <3ed5607f-0fe6-02cb-8c95-782913e65b5b@kernel.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net On Fri, Oct 14, 2016 at 09:25:59PM +0800, Chao Yu wrote: > On 2016/10/14 1:14, Jaegeuk Kim wrote: > > On Thu, Oct 13, 2016 at 06:33:19PM +0800, Chao Yu wrote: > >> Hi Jaegeuk, > >> > >> On 2016/10/13 7:23, Jaegeuk Kim wrote: > >>> This patch fixes using a wrong pointer for sum_page in f2fs_gc. > >>> > >>> Signed-off-by: Jaegeuk Kim > >>> --- > >>> fs/f2fs/gc.c | 10 +++++----- > >>> 1 file changed, 5 insertions(+), 5 deletions(-) > >>> > >>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > >>> index e48142f..9c18917 100644 > >>> --- a/fs/f2fs/gc.c > >>> +++ b/fs/f2fs/gc.c > >>> @@ -854,16 +854,16 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi, > >>> > >>> for (segno = start_segno; segno < end_segno; segno++) { > >>> > >>> - if (get_valid_blocks(sbi, segno, 1) == 0 || > >>> - unlikely(f2fs_cp_error(sbi))) > >>> - goto next; > >>> - > >>> /* find segment summary of victim */ > >>> sum_page = find_get_page(META_MAPPING(sbi), > >>> GET_SUM_BLOCK(sbi, segno)); > >>> - f2fs_bug_on(sbi, !PageUptodate(sum_page)); > >>> f2fs_put_page(sum_page, 0); > >>> > >>> + if (get_valid_blocks(sbi, segno, 1) == 0 || > >>> + !PageUptodate(sum_page) || > >> > >> Why uptodate flag of summary page can be cleared? someone truncates it? > > > > Well, it looks like no problem to remove this, since it will hit > > f2fs_cp_error(). I just intended to handle the above f2fs_bug_on here. > > If summary page becomes non-uptodate, it seems there is a bug in vfs/mm/f2fs, > why not keep it there to detect bug? I found that the above get_sum_page() loop can give a page which is not uptodate caused by EIO. Then, we would get the above bug_on, if we move f2fs_cp_error() case like this patch. Thoughts? Thanks, ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot