From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jaegeuk Kim Subject: Re: [PATCH v2] f2fs: get victim segment again after new cp Date: Fri, 22 Jul 2016 11:59:22 -0700 Message-ID: <20160722185922.GA36408@jaegeuk> References: <1469185711-27932-1-git-send-email-heyunlei@huawei.com> 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-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1bQffZ-0002Ri-MO for linux-f2fs-devel@lists.sourceforge.net; Fri, 22 Jul 2016 18:59:33 +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 1bQffX-0008B5-SR for linux-f2fs-devel@lists.sourceforge.net; Fri, 22 Jul 2016 18:59:33 +0000 Content-Disposition: inline In-Reply-To: <1469185711-27932-1-git-send-email-heyunlei@huawei.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: Yunlei He Cc: heyunlei@huwei.com, yuchao@huawei.com, linux-f2fs-devel@lists.sourceforge.net Hi Yunlei, On Fri, Jul 22, 2016 at 07:08:31PM +0800, Yunlei He wrote: > Previous selected segment may become free after write_checkpoint, > if we do garbage collect on this segment, and then new_curseg happen > to reuse it, it may cause f2fs_bug_on as below. > > panic+0x154/0x29c > do_garbage_collect+0x15c/0xaf4 > f2fs_gc+0x2dc/0x444 > f2fs_balance_fs.part.22+0xcc/0x14c > f2fs_balance_fs+0x28/0x34 > f2fs_map_blocks+0x5ec/0x790 > f2fs_preallocate_blocks+0xe0/0x100 > f2fs_file_write_iter+0x64/0x11c > new_sync_write+0xac/0x11c > vfs_write+0x144/0x1e4 > SyS_write+0x60/0xc0 > > Here, maybe we check sit and ssa type during reset_curseg. So, we check > segment is stale or not, and select a new victim to avoid this. > > Signed-off-by: Yunlei He > --- > fs/f2fs/gc.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c > index de6c41c..ec17096 100644 > --- a/fs/f2fs/gc.c > +++ b/fs/f2fs/gc.c > @@ -908,10 +908,14 @@ gc_more: > * enough free sections, we should flush dent/node blocks and do > * garbage collections. > */ > - if (__get_victim(sbi, &segno, gc_type) || prefree_segments(sbi)) > + if (__get_victim(sbi, &segno, gc_type) || prefree_segments(sbi)) { > write_checkpoint(sbi, &cpc); > - else if (has_not_enough_free_secs(sbi, 0)) If segno is NULL_SEGNO, we get a panic when checking the below conditions. Anyway, I don't think we need this condition at all. Let me remove them and just set NULL_SEGNO only after checkpoint. Please check the dev-test repo. Thanks, > + if(!get_valid_blocks(sbi, segno, sbi->segs_per_sec) > + || IS_CURSEC(sbi, segno / sbi->segs_per_sec)) > + segno = NULL_SEGNO; > + } else if (has_not_enough_free_secs(sbi, 0)) { > write_checkpoint(sbi, &cpc); > + } > } > > if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type)) > -- > 1.9.1 ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports.http://sdm.link/zohodev2dev