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 E75FCC61DA4 for ; Thu, 2 Feb 2023 13:57:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231691AbjBBN5H (ORCPT ); Thu, 2 Feb 2023 08:57:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49850 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229710AbjBBN5G (ORCPT ); Thu, 2 Feb 2023 08:57:06 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29B234CE7F for ; Thu, 2 Feb 2023 05:57:03 -0800 (PST) Received: from dggpeml500021.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4P70hL0c0gzfYq9; Thu, 2 Feb 2023 21:56:50 +0800 (CST) Received: from huawei.com (10.175.127.227) by dggpeml500021.china.huawei.com (7.185.36.21) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.34; Thu, 2 Feb 2023 21:57:00 +0800 From: Baokun Li To: CC: , , , , , , Subject: [PATCH] debugfs: check first journal block type when a tail-to-head reversal occurs in logdump Date: Thu, 2 Feb 2023 22:20:55 +0800 Message-ID: <20230202142055.2482087-1-libaokun1@huawei.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.127.227] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpeml500021.china.huawei.com (7.185.36.21) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org When logs are dumped, if the last description block in the journal area contains the first journal block as the data block, logs may be repeatedly printed or not completely printed. After the journal replay, we always restart logging from the first journal block. In this case, there are the following two cases: 1) If start == first, the first block is always skipped due to reversal. Therefore, the condition (blocknr == first_transaction_blocknr) for determining repeated printing does not take effect. As a result, logs are repeatedly printed. 2) If start != first, we will traverse backwards from the first non-data block after the last journal data block in the last description block, and the logs from the first journal block to this block will not be printed. That is, the dump log is incomplete. To solve this problem, we only need to check the type of the first log block when reversal occurs. If it is a non-log data block, we should continue to dump directly from the first block. Signed-off-by: Baokun Li --- debugfs/logdump.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/debugfs/logdump.c b/debugfs/logdump.c index b103cf1e..0019b6cf 100644 --- a/debugfs/logdump.c +++ b/debugfs/logdump.c @@ -740,6 +740,18 @@ static void dump_descriptor_block(FILE *out_file, } while (!(tag_flags & JBD2_FLAG_LAST_TAG)); + /* When a tail-to-head reversal occurs, we need to check whether + * there is a log that starts from the beginning again. + */ + if (*blockp > blocknr) { + journal_header_t first_header = {0}; + + read_journal_block("logdump", source, blocksize, + (char *)&first_header, sizeof(journal_header_t)); + if ((be32_to_cpu(first_header.h_magic) == JBD2_MAGIC_NUMBER) && + (be32_to_cpu(first_header.h_blocktype) == JBD2_DESCRIPTOR_BLOCK)) + blocknr = 1; + } *blockp = blocknr; } -- 2.31.1