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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05B98C433EF for ; Tue, 10 May 2022 02:36:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234854AbiEJCkZ (ORCPT ); Mon, 9 May 2022 22:40:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234844AbiEJCkQ (ORCPT ); Mon, 9 May 2022 22:40:16 -0400 Received: from SHSQR01.spreadtrum.com (mx1.unisoc.com [222.66.158.135]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2341224BD7; Mon, 9 May 2022 19:36:18 -0700 (PDT) Received: from SHSend.spreadtrum.com (shmbx04.spreadtrum.com [10.0.1.214]) by SHSQR01.spreadtrum.com with ESMTPS id 24A2ZHmq016228 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NO); Tue, 10 May 2022 10:35:17 +0800 (CST) (envelope-from Jing.Xia@unisoc.com) Received: from bj08259pcu.spreadtrum.com (10.0.74.59) by shmbx04.spreadtrum.com (10.0.1.214) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Tue, 10 May 2022 10:35:17 +0800 From: Jing Xia To: CC: , , , , , , Subject: [PATCH V2] writeback: Avoid skipping inode writeback Date: Tue, 10 May 2022 10:35:14 +0800 Message-ID: <20220510023514.27399-1-jing.xia@unisoc.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.0.74.59] X-ClientProxiedBy: SHCAS03.spreadtrum.com (10.0.1.207) To shmbx04.spreadtrum.com (10.0.1.214) X-MAIL: SHSQR01.spreadtrum.com 24A2ZHmq016228 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We have run into an issue that a task gets stuck in balance_dirty_pages_ratelimited() when perform I/O stress testing. The reason we observed is that an I_DIRTY_PAGES inode with lots of dirty pages is in b_dirty_time list and standard background writeback cannot writeback the inode. After studing the relevant code, the following scenario may lead to the issue: task1 task2 ----- ----- fuse_flush write_inode_now //in b_dirty_time writeback_single_inode __writeback_single_inode fuse_write_end filemap_dirty_folio __xa_set_mark:PAGECACHE_TAG_DIRTY lock inode->i_lock if mapping tagged PAGECACHE_TAG_DIRTY inode->i_state |= I_DIRTY_PAGES unlock inode->i_lock __mark_inode_dirty:I_DIRTY_PAGES lock inode->i_lock -was dirty,inode stays in -b_dirty_time unlock inode->i_lock if(!(inode->i_state & I_DIRTY_All)) -not true,so nothing done This patch moves the dirty inode to b_dirty list when the inode currently is not queued in b_io or b_more_io list at the end of writeback_single_inode. Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig CC: stable@vger.kernel.org Fixes: 0ae45f63d4ef ("vfs: add support for a lazytime mount option") Signed-off-by: Jing Xia --- fs/fs-writeback.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 591fe9cf1659..1fae0196292a 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -1712,6 +1712,10 @@ static int writeback_single_inode(struct inode *inode, */ if (!(inode->i_state & I_DIRTY_ALL)) inode_cgwb_move_to_attached(inode, wb); + else if (!(inode->i_state & I_SYNC_QUEUED) && + (inode->i_state & I_DIRTY)) + redirty_tail_locked(inode, wb); + spin_unlock(&wb->list_lock); inode_sync_complete(inode); out: -- 2.17.1