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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 8BCCCC433DF for ; Tue, 4 Aug 2020 07:57:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 99CAA22B40 for ; Tue, 4 Aug 2020 07:57:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729524AbgHDH5S (ORCPT ); Tue, 4 Aug 2020 03:57:18 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:37286 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727066AbgHDH5S (ORCPT ); Tue, 4 Aug 2020 03:57:18 -0400 Received: from DGGEMS407-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id D07BCF8FA70C7A9EB81C; Tue, 4 Aug 2020 15:57:15 +0800 (CST) Received: from [10.164.122.247] (10.164.122.247) by smtp.huawei.com (10.3.19.207) with Microsoft SMTP Server (TLS) id 14.3.487.0; Tue, 4 Aug 2020 15:57:13 +0800 Subject: Re: [f2fs-dev] [PATCH] f2fs: fix deadlock between quota writes and checkpoint To: Jaegeuk Kim CC: , , , Daeho Jeong References: <20200729070244.584518-1-jaegeuk@kernel.org> <670f35e1-872b-6602-320c-dd73bcb62510@huawei.com> <20200804035439.GA903802@google.com> From: Chao Yu Message-ID: <9a35fddd-2b67-c91e-2b1a-c63a285cd4ab@huawei.com> Date: Tue, 4 Aug 2020 15:57:13 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.9.1 MIME-Version: 1.0 In-Reply-To: <20200804035439.GA903802@google.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.164.122.247] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/8/4 11:54, Jaegeuk Kim wrote: > On 08/04, Chao Yu wrote: >> On 2020/7/29 15:02, Jaegeuk Kim wrote: >>> f2fs_write_data_pages(quota_mapping) >>> __f2fs_write_data_pages f2fs_write_checkpoint >>> * blk_start_plug(&plug); >>> * add bio in write_io[DATA] >>> - block_operations >>> - skip syncing quota by >>> >DEFAULT_RETRY_QUOTA_FLUSH_COUNT >>> - down_write(&sbi->node_write); >> >> f2fs_flush_merged_writes() will be called after block_operations(), why this doesn't >> help? > > Well, I think bio can be added after f2fs_flush_merged_writes() as well. - down_read(node_write) - f2fs_do_write_data_page - f2fs_trylock_op - f2fs_outplace_write_data - f2fs_submit_page_write bio only be added under node_write lock? during f2fs_flush_merged_writes(), node_write should have been held by checkpoint() avoiding quota data writeback & bio submission. > >> >>> - f2fs_write_single_data_page >>> - f2fs_do_write_data_page >>> - f2fs_outplace_write_data >>> - do_write_page >>> - f2fs_allocate_data_block >>> - down_write(node_write) >>> - f2fs_wait_on_all_pages(F2FS_WB_CP_DATA); >>> >>> Signed-off-by: Daeho Jeong >>> Signed-off-by: Jaegeuk Kim >>> --- >>> fs/f2fs/checkpoint.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c >>> index 8c782d3f324f0..99c8061da55b9 100644 >>> --- a/fs/f2fs/checkpoint.c >>> +++ b/fs/f2fs/checkpoint.c >>> @@ -1269,6 +1269,8 @@ void f2fs_wait_on_all_pages(struct f2fs_sb_info *sbi, int type) >>> if (type == F2FS_DIRTY_META) >>> f2fs_sync_meta_pages(sbi, META, LONG_MAX, >>> FS_CP_META_IO); >>> + else if (type == F2FS_WB_CP_DATA) >>> + f2fs_submit_merged_write(sbi, DATA); >>> io_schedule_timeout(DEFAULT_IO_TIMEOUT); >>> } >>> finish_wait(&sbi->cp_wait, &wait); >>> > . >