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 CB234CCA48B for ; Tue, 7 Jun 2022 19:46:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357706AbiFGTqQ (ORCPT ); Tue, 7 Jun 2022 15:46:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353476AbiFGSrj (ORCPT ); Tue, 7 Jun 2022 14:47:39 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9DFDEEB6; Tue, 7 Jun 2022 11:02:58 -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 ams.source.kernel.org (Postfix) with ESMTPS id B25F2B82375; Tue, 7 Jun 2022 18:02:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD22BC341CF; Tue, 7 Jun 2022 18:02:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654624975; bh=YsbqfK4bDhrH0z3BIe/ryhtT8bg72/Iiz12ahGehA0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H/RojdmLaxGdSdzAgxd9gm/e+2McS8G/2l6R+AKdFyYnhO9PkiERf1WO8tWgiiGh7 MfckLtNAgZ02cUplk+QJo6U3gv1rjCy9d6VBAuBVVsTKrgW2R5TS1bhok/ywPQpUER xjt+RIKwKHNwJe3nbHmaUDOGQFK+645MpLrCA0fY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ming Yan , Chao Yu , Jaegeuk Kim Subject: [PATCH 5.15 519/667] f2fs: fix deadloop in foreground GC Date: Tue, 7 Jun 2022 19:03:04 +0200 Message-Id: <20220607164950.269772700@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607164934.766888869@linuxfoundation.org> References: <20220607164934.766888869@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Chao Yu commit cfd66bb715fd11fde3338d0660cffa1396adc27d upstream. As Yanming reported in bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=215914 The root cause is: in a very small sized image, it's very easy to exceed threshold of foreground GC, if we calculate free space and dirty data based on section granularity, in corner case, has_not_enough_free_secs() will always return true, result in deadloop in f2fs_gc(). So this patch refactors has_not_enough_free_secs() as below to fix this issue: 1. calculate needed space based on block granularity, and separate all blocks to two parts, section part, and block part, comparing section part to free section, and comparing block part to free space in openned log. 2. account F2FS_DIRTY_NODES, F2FS_DIRTY_IMETA and F2FS_DIRTY_DENTS as node block consumer; 3. account F2FS_DIRTY_DENTS as data block consumer; Cc: stable@vger.kernel.org Reported-by: Ming Yan Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman --- fs/f2fs/segment.h | 32 ++++++++++++++++++++------------ 1 file changed, 20 insertions(+), 12 deletions(-) --- a/fs/f2fs/segment.h +++ b/fs/f2fs/segment.h @@ -571,11 +571,10 @@ static inline int reserved_sections(stru return GET_SEC_FROM_SEG(sbi, reserved_segments(sbi)); } -static inline bool has_curseg_enough_space(struct f2fs_sb_info *sbi) +static inline bool has_curseg_enough_space(struct f2fs_sb_info *sbi, + unsigned int node_blocks, unsigned int dent_blocks) { - unsigned int node_blocks = get_pages(sbi, F2FS_DIRTY_NODES) + - get_pages(sbi, F2FS_DIRTY_DENTS); - unsigned int dent_blocks = get_pages(sbi, F2FS_DIRTY_DENTS); + unsigned int segno, left_blocks; int i; @@ -601,19 +600,28 @@ static inline bool has_curseg_enough_spa static inline bool has_not_enough_free_secs(struct f2fs_sb_info *sbi, int freed, int needed) { - int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES); - int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS); - int imeta_secs = get_blocktype_secs(sbi, F2FS_DIRTY_IMETA); + unsigned int total_node_blocks = get_pages(sbi, F2FS_DIRTY_NODES) + + get_pages(sbi, F2FS_DIRTY_DENTS) + + get_pages(sbi, F2FS_DIRTY_IMETA); + unsigned int total_dent_blocks = get_pages(sbi, F2FS_DIRTY_DENTS); + unsigned int node_secs = total_node_blocks / BLKS_PER_SEC(sbi); + unsigned int dent_secs = total_dent_blocks / BLKS_PER_SEC(sbi); + unsigned int node_blocks = total_node_blocks % BLKS_PER_SEC(sbi); + unsigned int dent_blocks = total_dent_blocks % BLKS_PER_SEC(sbi); + unsigned int free, need_lower, need_upper; if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING))) return false; - if (free_sections(sbi) + freed == reserved_sections(sbi) + needed && - has_curseg_enough_space(sbi)) + free = free_sections(sbi) + freed; + need_lower = node_secs + dent_secs + reserved_sections(sbi) + needed; + need_upper = need_lower + (node_blocks ? 1 : 0) + (dent_blocks ? 1 : 0); + + if (free > need_upper) return false; - return (free_sections(sbi) + freed) <= - (node_secs + 2 * dent_secs + imeta_secs + - reserved_sections(sbi) + needed); + else if (free <= need_lower) + return true; + return !has_curseg_enough_space(sbi, node_blocks, dent_blocks); } static inline bool f2fs_is_checkpoint_ready(struct f2fs_sb_info *sbi)