From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 62A363DAC01 for ; Mon, 25 Mar 2024 13:46:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711374405; cv=none; b=h5ypvpXkn5gdvKn0QPOaI0VAnygxKc256josYKt6esNw4Jjfo1rDx7bR74MXdsfClB7rDFbXw5uOvBIxj3US6O91i36r7f7RSA4xABi9TuhOT4XOWQgxpUwmATUcNeTqvfj0xuHB8frYWde4Po9i5r38aDoRN6YGsjVccuTX8ZE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711374405; c=relaxed/simple; bh=CH/dCXWNi2/KMcpRzScslB9UiE4F2GrOGvUbtKluF50=; h=Subject:To:CC:References:From:Message-ID:Date:MIME-Version: In-Reply-To:Content-Type; b=ZkiL+OZtXGF6WV6/LK0rwGw7sF1NLoS9J6rztAy7JXttHLOZ3+s3r8byGj57CeKlLPIiXbpW1h0AUPCt5pRYbFOHeHZwJTG+79npd6hhifZGAfiI/wj/F1632ybN/ASHAHG0JaoWujEdeOg+yHsEdNVBxPFW/1EXOyr0YKUDzGQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.174]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4V3Dfx0HVszXjks; Mon, 25 Mar 2024 21:43:53 +0800 (CST) Received: from kwepemm600013.china.huawei.com (unknown [7.193.23.68]) by mail.maildlp.com (Postfix) with ESMTPS id 4ED3B140258; Mon, 25 Mar 2024 21:46:37 +0800 (CST) Received: from [10.174.178.46] (10.174.178.46) by kwepemm600013.china.huawei.com (7.193.23.68) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Mon, 25 Mar 2024 21:46:36 +0800 Subject: Re: [PATCH V2] ubifs: correct UBIFS_DFS_DIR_LEN macro definition and improve code clarity To: ZhaoLong Wang , , , CC: , , , References: <20240325125713.95035-1-wangzhaolong1@huawei.com> From: Zhihao Cheng Message-ID: <3fce4fde-0163-4fd4-feb0-2a68aa785e2f@huawei.com> Date: Mon, 25 Mar 2024 21:46:35 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <20240325125713.95035-1-wangzhaolong1@huawei.com> Content-Type: text/plain; charset="gbk"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemm600013.china.huawei.com (7.193.23.68) ÔÚ 2024/3/25 20:57, ZhaoLong Wang дµÀ: > The UBIFS_DFS_DIR_LEN macro, which defines the maximum length of the UBIFS > debugfs directory name, has an incorrect formula and misleading comments. > The current formula is (3 + 1 + 2*2 + 1), which assumes that both UBI device > number and volume ID are limited to 2 characters. However, UBI device number > ranges from 0 to 37 (2 characters), and volume ID ranges from 0 to 127 (up > to 3 characters). > > Although the current code works due to the cancellation of mathematical > errors (9 + 1 = 10, which matches the correct UBIFS_DFS_DIR_LEN value), it > can lead to confusion and potential issues in the future. > > This patch aims to improve the code clarity and maintainability by making > the following changes: > > 1. Corrects the UBIFS_DFS_DIR_LEN macro definition to (3 + 1 + 2 + 3 + 1), > accommodating the maximum lengths of both UBI device number and volume ID, > plus the separators and null terminator. > 2. Updates the snprintf calls to use UBIFS_DFS_DIR_LEN instead of > UBIFS_DFS_DIR_LEN + 1, removing the unnecessary +1. > 3. Modifies the error checks to compare against UBIFS_DFS_DIR_LEN using >= > instead of >, aligning with the corrected macro definition. > 4. Removes the redundant +1 in the dfs_dir_name array definitions in ubi.h > and debug.h. > 5. Renames the duplicated UBIFS_DFS_DIR_LEN and UBIFS_DFS_DIR_NAME macros in > the sysfs-related code (sysfs.c and ubifs.h) to UBIFS_SYSFS_DIR_LEN and > UBIFS_SYSFS_DIR_NAME, respectively, to differentiate their usage from the > debugfs constants. > [...] > diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h > index 1f3ea879d93a..549e147c5ce5 100644 > --- a/fs/ubifs/ubifs.h > +++ b/fs/ubifs/ubifs.h > @@ -159,10 +159,11 @@ > > /* > * The UBIFS sysfs directory name pattern and maximum name length (3 for "ubi" > - * + 1 for "_" and plus 2x2 for 2 UBI numbers and 1 for the trailing zero byte. > + * + 1 for "_" and 2 for UBI device numbers and 3 for volume number and 1 for > + * the trailing zero byte. > */ > -#define UBIFS_DFS_DIR_NAME "ubi%d_%d" > -#define UBIFS_DFS_DIR_LEN (3 + 1 + 2*2 + 1) > +#define UBIFS_SYSFS_DIR_NAME "ubi%d_%d" > +#define UBIFS_SYSFS_DIR_LEN (3 + 1 + 2 + 3 + 1) I don't thinks this renaming is necessary, just remove it from "ubifs.h" like v1 does. > > /* > * Lockdep classes for UBIFS inode @ui_mutex. >