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 X-Spam-Level: X-Spam-Status: No, score=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC984C433B4 for ; Tue, 27 Apr 2021 12:18:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A63CD61040 for ; Tue, 27 Apr 2021 12:18:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236157AbhD0MSy (ORCPT ); Tue, 27 Apr 2021 08:18:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53828 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235652AbhD0MSx (ORCPT ); Tue, 27 Apr 2021 08:18:53 -0400 Received: from mail-wr1-x430.google.com (mail-wr1-x430.google.com [IPv6:2a00:1450:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7FD4C061574; Tue, 27 Apr 2021 05:18:08 -0700 (PDT) Received: by mail-wr1-x430.google.com with SMTP id h4so50209599wrt.12; Tue, 27 Apr 2021 05:18:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=nwYYP5GSWCGL21FGByVMgOz2Zp6qeL8goYySzJMMPZI=; b=pZ06IqKYI9QOQmdWQaJ3fwVk9NysimAqNIiWEmmGBUNFB6/SBToqHrjezZNFR+T0ln 6G5rDTPSrf6k+jrApT6HaHex+sPZJVIVnpiuO08nIiKQHyj7zAZ9qaMVYvgLkvLq4nXs jGPAjikF/Hzv1FZ/kQN9RDAVlX0d9SWYxkTL8kMzhmqznq28+dou5e8Nmbtg1HCLQd7H ozDghsaljxPnT/+RHhF8h3heCNxQ1EWlDi0NP3R5EZ1dSffITkAEtwJh2mUlqqcYcgwQ H/P/gddHyp3P2gzU5CRmnB4bCTY5rJ0rM9cmziOeDRY0QX+5hwR3yc5bYL6ggsAkMX2r W1mw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=nwYYP5GSWCGL21FGByVMgOz2Zp6qeL8goYySzJMMPZI=; b=YqqrU1gD8+ooTyhGsHsX0tgamKEGROrLGaeSMtFGW0ICdKfWtneao96A3lBrnFVpku o9ZxvYEK3jeHVSh60iUOx9M5aC5coR4oQfRUQNV0fGy7M3Ncap+6K99COVMyV4uSYKu+ JaRPcEvtb9TUezAoI4PNWXHl8YlgfDBz2hRKyh2/iS2mfYUDrzxhB2l3Hxi7DL1yRHyi HVxssL9nC/tiEVt2stGkNyaTffcbVKF1lCaz1/AdKwWcdhM7+r+ms5NXog6+IhEbXksf z4g+c6CATMI4cauDNMt8eqW6ED9+cxV3RLCJa1bfEBa1M/dpX0F+FeOsoJppoaLwQhM4 UeJg== X-Gm-Message-State: AOAM533c9zQV602y9pCsRA/vyErMFvMNnxu83ojCBLxu9VATijvEpDAI wwuagij9907EziO0ecYJy7/LfMaYyXc= X-Google-Smtp-Source: ABdhPJzam8dJzwU87MEnV6VEPQnVzXnAmet8lKqdZKK18xwRA1zD6QCWRZplqtdKDY2xZQFBKUSjSw== X-Received: by 2002:adf:d1e8:: with SMTP id g8mr1791117wrd.80.1619525887682; Tue, 27 Apr 2021 05:18:07 -0700 (PDT) Received: from ard0534 ([102.158.125.167]) by smtp.gmail.com with ESMTPSA id q4sm1108136wrs.21.2021.04.27.05.18.06 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Tue, 27 Apr 2021 05:18:07 -0700 (PDT) Date: Tue, 27 Apr 2021 13:18:04 +0100 From: Khaled Romdhani To: David Sterba Cc: clm@fb.com, josef@toxicpanda.com, dsterba@suse.com, linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH-next] fs/btrfs: Fix uninitialized variable Message-ID: <20210427121804.GA16179@ard0534> References: <20210423124201.11262-1-khaledromdhani216@gmail.com> <20210426201929.GI7604@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210426201929.GI7604@suse.cz> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Mon, Apr 26, 2021 at 10:19:29PM +0200, David Sterba wrote: > On Fri, Apr 23, 2021 at 01:42:01PM +0100, Khaled ROMDHANI wrote: > > The variable 'zone' is uninitialized which > > introduce some build warning. > > > > It is not always set or overwritten within > > the function. So explicitly initialize it. > > > > Reported-by: kernel test robot > > Signed-off-by: Khaled ROMDHANI > > --- > > fs/btrfs/zoned.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/fs/btrfs/zoned.c b/fs/btrfs/zoned.c > > index 432509f4b3ac..42f99b25127f 100644 > > --- a/fs/btrfs/zoned.c > > +++ b/fs/btrfs/zoned.c > > @@ -136,7 +136,7 @@ static int sb_write_pointer(struct block_device *bdev, struct blk_zone *zones, > > */ > > static inline u32 sb_zone_number(int shift, int mirror) > > { > > - u64 zone; > > + u64 zone = 0; > > This is exactly same as v1 > https://lore.kernel.org/linux-btrfs/20210413130604.11487-1-khaledromdhani216@gmail.com/ > > It does fix the build warning but does not make sense in the code > because it would would silently let mirror == 4 pass. I think there was > enough feedback under the previous posts how to fix that properly. Yes, it fixes the build warning. I implemented a tiny test program before sending the patch. In which I explicitly set 'm=5' to check the change results: [356843.099365] assertion failed: z, in /home/khaled/fs_btrfs/test3.c:30 >From the above output message, I think that it catchs the assertion. Sorry, but let me know if I am missing something. I absolutly agree with you regarding the waste of memory when doing some pointless initializations. I will, come back with a V2. Thanks.