From patchwork Wed Feb 7 02:01:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhiguo Niu X-Patchwork-Id: 13548005 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 lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9DADFC48297 for ; Wed, 7 Feb 2024 02:02:07 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1rXXGI-0004bx-Ni; Wed, 07 Feb 2024 02:02:07 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1rXXGG-0004be-Nz for linux-f2fs-devel@lists.sourceforge.net; Wed, 07 Feb 2024 02:02:05 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Type:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=LaJn8xlKsjzx/iIIxNAPS5wLhotT9xnLZevse49RQwg=; b=Jz0QGTmTZl/WeHO9LGVXQAUJZ8 ONQgY7wtOB/vdJmAIOeajEMHCbEWqG1CJhnWmsAotNz9WLmNSracNG2MIiVZmjSpdksU/J8uO7CVE UfVzsRoxtPlc9y6ZwgPwbU3kYNR7WqoKz4a7Hgjlk4LPyIww1Na/C5u/3sGQ1/cuuH9M=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject: CC:To:From:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=LaJn8xlKsjzx/iIIxNAPS5wLhotT9xnLZevse49RQwg=; b=MqDSx5sTxwcMRHp5N0lFQPwzJT AYKTzB9EmOxdFS87GIJYrhgVvw14YYxNVyool5Mp+CxX84NptMZ7UTEt1kl4sLjygffJAjtTY3afT ABgx7FTSaUDVjp+LHbrSScy4w7VfSF5fODW/ukx9o3TdrW9X5bPweDFlbWeWwA4TeoJg=; Received: from mx1.unisoc.com ([222.66.158.135] helo=SHSQR01.spreadtrum.com) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1rXXGF-00072J-Km for linux-f2fs-devel@lists.sourceforge.net; Wed, 07 Feb 2024 02:02:05 +0000 Received: from dlp.unisoc.com ([10.29.3.86]) by SHSQR01.spreadtrum.com with ESMTP id 41721TTX075531; Wed, 7 Feb 2024 10:01:29 +0800 (+08) (envelope-from Zhiguo.Niu@unisoc.com) Received: from SHDLP.spreadtrum.com (bjmbx02.spreadtrum.com [10.0.64.8]) by dlp.unisoc.com (SkyGuard) with ESMTPS id 4TV3J13RTXz2K4cHw; Wed, 7 Feb 2024 10:01:21 +0800 (CST) Received: from bj08434pcu.spreadtrum.com (10.0.73.87) by BJMBX02.spreadtrum.com (10.0.64.8) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Wed, 7 Feb 2024 10:01:26 +0800 From: Zhiguo Niu To: , Date: Wed, 7 Feb 2024 10:01:01 +0800 Message-ID: <1707271264-5551-2-git-send-email-zhiguo.niu@unisoc.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1707271264-5551-1-git-send-email-zhiguo.niu@unisoc.com> References: <1707271264-5551-1-git-send-email-zhiguo.niu@unisoc.com> MIME-Version: 1.0 X-Originating-IP: [10.0.73.87] X-ClientProxiedBy: SHCAS03.spreadtrum.com (10.0.1.207) To BJMBX02.spreadtrum.com (10.0.64.8) X-MAIL: SHSQR01.spreadtrum.com 41721TTX075531 X-Headers-End: 1rXXGF-00072J-Km Subject: [f2fs-dev] [PATCH v2 1/4] f2fs: correct counting methods of free_segments in __set_inuse X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: ke.wang@unisoc.com, linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, hongyu.jin@unisoc.com, zhiguo.niu@unisoc.com, niuzhiguo84@gmail.com Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net There is a corner scenario on a small-capacity partition with 64MB size: 1. The main area has a total of 24 segments, and there are no free segments left shown from the free_segmap bitmap and free_secmap in free_segmap_info. --------------------------------------------------------------------- bitmap value: ffffffffffffffff --------------------------------------------------------------------- 2. When doing gc, an out-of-bounds segment with segno=24 is allocated. Because CONFIG_F2FS_CHECK_FS is not enabled, f2fs_bug_on in get_new_segment just print warning log but the subsequent process continues to run. --------------------------------------------------------------------- got_it: /* set it as dirty segment in free segmap */ f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap)); __set_inuse(sbi, segno); ---------------------------------------------------------------------- 3. __set_inuse directly sets free_i->free_segments--, As a result, free_i->free_segments=-1, as shown in the following coredump information: ---------------------------------------------------------------------- crash_arm64> struct free_segmap_info 0xffffff8084d9a000 -x struct free_segmap_info { start_segno = 0x7, free_segments = 0xffffffff, free_sections = 0x0, ---------------------------------------------------------------------- This is unreasonable and will cause free_segments and free_sections counts mismatch if there are segments released as free. So same counting methods like free_sections should be used to free_segments. Signed-off-by: Zhiguo Niu --- fs/f2fs/segment.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index 8129be7..f2847f1 100644 --- a/fs/f2fs/segment.h +++ b/fs/f2fs/segment.h @@ -463,8 +463,8 @@ static inline void __set_inuse(struct f2fs_sb_info *sbi, struct free_segmap_info *free_i = FREE_I(sbi); unsigned int secno = GET_SEC_FROM_SEG(sbi, segno); - set_bit(segno, free_i->free_segmap); - free_i->free_segments--; + if (!test_and_set_bit(segno, free_i->free_segmap)) + free_i->free_segments--; if (!test_and_set_bit(secno, free_i->free_secmap)) free_i->free_sections--; }