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=-7.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B56A9C433DF for ; Fri, 19 Jun 2020 05:56:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8F7D520809 for ; Fri, 19 Jun 2020 05:56:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592546204; bh=9lQMKLDkxfUoyF2wJGr/cl+gMGQit45i/+nfTpmUwJI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=1uHY0kDoHOowmTl51rWM0gbov297WLUQRU3a0ASeBEg+yLD6RtIfDTtpMBmOwl5r8 JefeEI6I+3rmTg5iYm7vFc6dXUD1JTkrfaNVaPfv6yqNiOskHBpyTr6iJjKPVfop42 QNwIfsNi62xeZWsMQQRhFF6h2vd2DqWcEQxGaf/k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728321AbgFSF4m (ORCPT ); Fri, 19 Jun 2020 01:56:42 -0400 Received: from mail.kernel.org ([198.145.29.99]:56378 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725446AbgFSF4m (ORCPT ); Fri, 19 Jun 2020 01:56:42 -0400 Received: from localhost (unknown [104.132.1.66]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 6B7A9207DD; Fri, 19 Jun 2020 05:56:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592546201; bh=9lQMKLDkxfUoyF2wJGr/cl+gMGQit45i/+nfTpmUwJI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uNyadC1mwnLWhHwUt+8csXiE/lsUF5oJSfigS3rFy6B8uhc0tavJ6DOO3AGawjuBU I1CBJH9egCmg6ovDJCCmT7oUGDf82nuO3V4v/8WQQUv2wjHwRTVS16Ec8IPwBnDjmd VsJ9t+YjDSZGhTNqSaHdPxLUf2bhFTe4Vgj+KTLA= Date: Thu, 18 Jun 2020 22:56:40 -0700 From: Jaegeuk Kim To: Chao Yu Cc: linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, chao@kernel.org Subject: Re: [PATCH 3/5] f2fs: shrink node_write lock coverage Message-ID: <20200619055640.GD227771@google.com> References: <20200618063625.110273-1-yuchao0@huawei.com> <20200618063625.110273-3-yuchao0@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200618063625.110273-3-yuchao0@huawei.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/18, Chao Yu wrote: > - to avoid race between checkpoint and quota file writeback, it > just needs to hold read lock of node_write in writeback path. > - node_write lock has covered all LFS data write paths, it's not > necessary, we only need to hold node_write lock at write path of > quota file. I've added this: This refactors commit ca7f76e68074 ("f2fs: fix wrong discard space"). > > Signed-off-by: Chao Yu > --- > fs/f2fs/compress.c | 18 +++++++++++++++--- > fs/f2fs/data.c | 12 ++++++++++++ > fs/f2fs/segment.c | 11 ----------- > 3 files changed, 27 insertions(+), 14 deletions(-) > > diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c > index 36b51795b0c3..3ff6c0305ec6 100644 > --- a/fs/f2fs/compress.c > +++ b/fs/f2fs/compress.c > @@ -1096,8 +1096,16 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc, > loff_t psize; > int i, err; > > - if (!IS_NOQUOTA(inode) && !f2fs_trylock_op(sbi)) > + if (IS_NOQUOTA(inode)) { > + /* > + * We need to wait for node_write to avoid block allocation during > + * checkpoint. This can only happen to quota writes which can cause > + * the below discard race condition. > + */ > + down_read(&sbi->node_write); > + } else if (!f2fs_trylock_op(sbi)) { > return -EAGAIN; > + } > > set_new_dnode(&dn, cc->inode, NULL, NULL, 0); > > @@ -1203,7 +1211,9 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc, > set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN); > > f2fs_put_dnode(&dn); > - if (!IS_NOQUOTA(inode)) > + if (IS_NOQUOTA(inode)) > + up_read(&sbi->node_write); > + else > f2fs_unlock_op(sbi); > > spin_lock(&fi->i_size_lock); > @@ -1230,7 +1240,9 @@ static int f2fs_write_compressed_pages(struct compress_ctx *cc, > out_put_dnode: > f2fs_put_dnode(&dn); > out_unlock_op: > - if (!IS_NOQUOTA(inode)) > + if (IS_NOQUOTA(inode)) > + up_read(&sbi->node_write); > + else > f2fs_unlock_op(sbi); > return -EAGAIN; > } > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c > index c78ce08f6400..cbdf062d3562 100644 > --- a/fs/f2fs/data.c > +++ b/fs/f2fs/data.c > @@ -2719,8 +2719,20 @@ int f2fs_write_single_data_page(struct page *page, int *submitted, > > /* Dentry/quota blocks are controlled by checkpoint */ > if (S_ISDIR(inode->i_mode) || IS_NOQUOTA(inode)) { > + /* > + * We need to wait for node_write to avoid block allocation during > + * checkpoint. This can only happen to quota writes which can cause > + * the below discard race condition. > + */ > + if (IS_NOQUOTA(inode)) > + down_read(&sbi->node_write); > + > fio.need_lock = LOCK_DONE; > err = f2fs_do_write_data_page(&fio); > + > + if (IS_NOQUOTA(inode)) > + up_read(&sbi->node_write); > + > goto done; > } > > diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c > index 5b2a6f865a6d..cb861ed98ee3 100644 > --- a/fs/f2fs/segment.c > +++ b/fs/f2fs/segment.c > @@ -3107,14 +3107,6 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, > type = CURSEG_COLD_DATA; > } > > - /* > - * We need to wait for node_write to avoid block allocation during > - * checkpoint. This can only happen to quota writes which can cause > - * the below discard race condition. > - */ > - if (IS_DATASEG(type)) > - down_write(&sbi->node_write); > - > down_read(&SM_I(sbi)->curseg_lock); > > mutex_lock(&curseg->curseg_mutex); > @@ -3180,9 +3172,6 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page, > > up_read(&SM_I(sbi)->curseg_lock); > > - if (IS_DATASEG(type)) > - up_write(&sbi->node_write); > - > if (put_pin_sem) > up_read(&sbi->pin_sem); > } > -- > 2.18.0.rc1