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 2A767C04AA5 for ; Wed, 24 Aug 2022 20:30:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240389AbiHXUan (ORCPT ); Wed, 24 Aug 2022 16:30:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233796AbiHXUam (ORCPT ); Wed, 24 Aug 2022 16:30:42 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE0FB42ACE for ; Wed, 24 Aug 2022 13:30:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 5A57160F50 for ; Wed, 24 Aug 2022 20:30:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EF59C433C1; Wed, 24 Aug 2022 20:30:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1661373040; bh=KhuS2aA1cGvG8nGq+Lnvn6JqXWMq3xDEeS47IiRZhRs=; h=Date:From:To:Subject:References:In-Reply-To:From; b=onWIBk5pqvcS71A0KUMxGFzrgQj6rmzCCcUE0SKuj3rM6aCQp1bDza3jfYDt4SnRT 8rCyTnB3indPyaDcRxMCPYlupDi/C2qIjZAMNb0Nadee4PLu4gNFSrgaBRx6m6jd7/ blJE05rAjxlw5bAqrKnhdBsDWN7uZBe/sEA0jsWIPDoQ9eo8HqPJMTC0Tg2AZz1ELk 6xz3a6cl5jBPjqK5C0aM3vyQvmi6Ab/OmiTTl9GE7v7OuuDgXVvAv78rVSHupem0rV pkTkPeQUMB+QBh1OvKmTDWtRy6hhXzY/WNjSHdqimnqOydWvAzs4BhqsuPkyKkFLTF xLKX0YzUXtyHg== Date: Wed, 24 Aug 2022 13:30:38 -0700 From: Jaegeuk Kim To: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net Subject: Re: [PATCH 2/2 v2] f2fs: complete checkpoints during remount Message-ID: References: <20220819231514.3609958-1-jaegeuk@kernel.org> <20220819231514.3609958-2-jaegeuk@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220819231514.3609958-2-jaegeuk@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Otherwise, pending checkpoints can contribute a race condition to give a quota warning. - Thread - checkpoint thread add checkpoints to the list do_remount() down_write(&sb->s_umount); f2fs_remount() block_operations() down_read_trylock(&sb->s_umount) = 0 up_write(&sb->s_umount); f2fs_quota_sync() dquot_writeback_dquots() WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); Or, do_remount() down_write(&sb->s_umount); f2fs_remount() create a ckpt thread f2fs_enable_checkpoint() adds checkpoints wait for f2fs_sync_fs() trigger another pending checkpoint block_operations() down_read_trylock(&sb->s_umount) = 0 up_write(&sb->s_umount); f2fs_quota_sync() dquot_writeback_dquots() WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); Signed-off-by: Jaegeuk Kim --- Change log from v1: - add one more case fs/f2fs/super.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 4f2ff50b247c..0f29c759a898 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2185,6 +2185,9 @@ static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi) f2fs_up_write(&sbi->gc_lock); f2fs_sync_fs(sbi->sb, 1); + + /* Let's ensure there's no pending checkpoint anymore */ + f2fs_flush_ckpt_thread(sbi); } static int f2fs_remount(struct super_block *sb, int *flags, char *data) @@ -2350,6 +2353,9 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data) f2fs_stop_ckpt_thread(sbi); need_restart_ckpt = true; } else { + /* Flush if the prevous checkpoint, if exists. */ + f2fs_flush_ckpt_thread(sbi); + err = f2fs_start_ckpt_thread(sbi); if (err) { f2fs_err(sbi, -- 2.37.1.595.g718a3a8f04-goog