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 93529C7618D for ; Thu, 6 Apr 2023 06:44:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235569AbjDFGoK (ORCPT ); Thu, 6 Apr 2023 02:44:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52290 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235269AbjDFGoI (ORCPT ); Thu, 6 Apr 2023 02:44:08 -0400 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71AEB6581; Wed, 5 Apr 2023 23:44:06 -0700 (PDT) Received: by mail-pl1-x632.google.com with SMTP id f22so32555980plr.0; Wed, 05 Apr 2023 23:44:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1680763446; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=+XBnQxjP2ylYL48AsMsqJUUlZkp52VkN+BigcNo4SiQ=; b=dx/VJIgP0dFPwE+hAodDjLSlhr9c9dcTApIXN+gKo1mgNohBB3II2KivA6IEyDZLqx TA6TDO6Q1TJMUHN6FB+qLuc7ucYJbcJiyfUNSwxYFk/pIr5LqAbTm94O1RMxKlph73CT 8Dj4NJuOiySxYXRSK9SDEKPP7XgVTx3imOC41xbkX/5JkQL2MkFzyB5ITDzW/OhoFkno AJKbP0XSs6NVjQDqLxHVmf9+Q3HYLSnuRSosRQBccfXJAk53zoLgTbWbLQ+6PpfT20Q7 z2xgvtLDGqeMOEXEo0QM2RCJQBG7U3tYgyqYfcU6rF+TMQbQI9zyN83Obyp3Yn5bNZdz hnqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1680763446; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=+XBnQxjP2ylYL48AsMsqJUUlZkp52VkN+BigcNo4SiQ=; b=g/nxLy2lXAUMyMWLw07NEeyGUbTqXG5+ILcHnDjxsM/IewzNlqrdhThUTjk+ay0rOo 6mOl2RKZS3tzkaJeoZ5zj7MJYe/fTKAaGvJNot1gDOqUxjaXCX9YBfQ+IcxyEvUrqiTi eWAnqWhGPO77YN+uGTM6rNXgoxdcWyDutAd6bZqeR62TFiOX7iX/mZBzHUFd38c/vL8c HLA/I5gJV31NiulizMKLahDEfTbACSg4/fqCKF0eNfA1q5FmIl6JPjhDipYG+btE1fJy 9/qnumuYxzuOQRcBQgp9+UodgTovWm2rFQddq9SE7GzTsiynFuEbFDtN5jPwqGQJ85PJ lcKg== X-Gm-Message-State: AAQBX9cGFx9kRoF1n0rZlA+TtXfdbJlcGZfui2hzVKkVdPctESm9xUJk KklqLMJaIPIffGuIV5DPZzo= X-Google-Smtp-Source: AKy350Z3rmYRXzZpzHbV5gyGNdkjtZmonHc6/5yTJdzviBSj3FxsREROlrg54GkiXB3w2PE9gy1DMA== X-Received: by 2002:a17:903:1205:b0:19f:36b1:c35 with SMTP id l5-20020a170903120500b0019f36b10c35mr10603846plh.64.1680763445834; Wed, 05 Apr 2023 23:44:05 -0700 (PDT) Received: from C02FG34WMD6R.bytedance.net ([61.213.176.12]) by smtp.gmail.com with ESMTPSA id iw3-20020a170903044300b0019a74841c9bsm614436plb.192.2023.04.05.23.44.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 05 Apr 2023 23:44:05 -0700 (PDT) From: wuchi To: tytso@mit.edu, adilger.kernel@dilger.ca, ojaswin@linux.ibm.com, ritesh.list@gmail.com, David.Laight@aculab.com Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] ext4: simplify 32bit calculation of lblk Date: Thu, 6 Apr 2023 14:44:00 +0800 Message-Id: <20230406064400.2917-1-wuchi.zero@gmail.com> X-Mailer: git-send-email 2.37.3 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org commit (ext4: fix 32bit overflow in ext4_ext_find_goal()) uses value compare to fix 32bit overflow. The resion is that (block - ext_block) will overflow and cast u32 to u64. eg: -1(u32) cast to 0xffffffff(u64) which wasn't correct here. Remove the brackets will solve it simply. Suggested-by: David Laight Signed-off-by: wuchi --- fs/ext4/extents.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 3559ea6b0781..254d380ff46e 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -237,10 +237,7 @@ static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex); ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block); - if (block > ext_block) - return ext_pblk + (block - ext_block); - else - return ext_pblk - (ext_block - block); + return ext_pblk + block - ext_block; } /* it looks like index is empty; -- 2.20.1