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 C48E9C433EF for ; Mon, 21 Feb 2022 00:16:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244947AbiBUAQr (ORCPT ); Sun, 20 Feb 2022 19:16:47 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:46006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245348AbiBUAQq (ORCPT ); Sun, 20 Feb 2022 19:16:46 -0500 Received: from mout.gmx.net (mout.gmx.net [212.227.15.15]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8178E4476C; Sun, 20 Feb 2022 16:16:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1645402560; bh=u55hKlChXTEXIJuV+e0xiIjiT2nKtCrwDTUv/GZniC8=; h=X-UI-Sender-Class:Date:Subject:To:Cc:References:From:In-Reply-To; b=SC+12ipn9rbHMsrVsmYy3Un09pxQVpkeoSYVL7Fp76hgJ8ynyDYZDTEOwe8xxl3W1 iCr0qqG1r3UuIJkMV49Fc6EfibX2It0gNibwDTnDaW6FDOckJNJi2SJEFvWLMmMm4r YZY1P/nbxYR/sm74d4/3jwSyLE1j7ub86SJqAGiA= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.net (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1Msq2E-1oEioR24W8-00tBUZ; Mon, 21 Feb 2022 01:16:00 +0100 Message-ID: <0a2e57ad-2973-ea01-ceda-3262cde1f5aa@gmx.com> Date: Mon, 21 Feb 2022 08:15:52 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH] btrfs: Initialize ret to 0 in scrub_simple_mirror() Content-Language: en-US To: Souptick Joarder , clm@fb.com, josef@toxicpanda.com, dsterba@suse.com, nathan@kernel.org, ndesaulniers@google.com Cc: linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, kernel test robot References: <20220220144606.5695-1-jrdr.linux@gmail.com> From: Qu Wenruo In-Reply-To: <20220220144606.5695-1-jrdr.linux@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:C8JAjspcmErs2qvGcN+rf+gs5pzGazDeRknGb4nSBztbmyzskiA m9rvdxjYIuSlPwQKNsJs1CwrpBoPxYQ/puNKMgElBHkhgjzY//jcZtbFn7w+HX377mox0yY 8ksMF6XX0qOIuy7Un30A/N+W7hwryUj0Bkya3FCNQuPjoNLn8Hry02cTy+19fs8f/UnaeFG iyqjwOaM/nUeUHDRhEE8Q== X-UI-Out-Filterresults: notjunk:1;V03:K0:yHT8ct1YwXg=:4qNAuuwGPL0dLqTUBv6r62 zj5vSKm4vU4+6oz1vjcziodlfbEPOa0pj9GfCrG9SS3JMaiwIhYjSbPr9nCXZZuojMOxWMQFQ 7RtidxnLHDRq+JsCooYST+0Inw154w8Km/qCwm/Z0d8OV6on0YCDmuk9FLJlFdQBhoCGg/TfA FIlIDGSyqfnZgO1AlrbK1KSLNHZoTD4VJhwiHXmzsBPBYWXLK5XqKXwzAzPKwj6UvqGg+Zvli Uvnf0b7sxgbybCb0VLbjvlSqYg+UxA/h3z1zcAi40yo+ywuxDWgt8FI9pNKYdZLOHYIjDi4vu QKTVAWA+rdoErEMn9NDwKK8kfJ8wBqhFC+VL8AZUlH5r2afOLE5kiuBp200ONqKP+Q1vCRr2t UtfIqgkIs6X3V45EwoiZoHdXGiEC9lKr39EJWn1ekWDtD8OkvujklKpvnfVb3HPudNH2+gW+R +9mEP2wbKPyfdu0YN+IHxu6OAxhCPoaFkaBI6OZJmTsXctGIetf0q83mTcyNPV0hv/3WswbcA UY+6UTD327ePsxsSknt8FjWaddkcRuvYVXhsJEHLfnN1KxApInZc21ZMzGKnw5lXBcHjsnKpD mRrGk0Hl5hTuTP/IH0/lXrbWO0lJ48nHkeJ+5GQl451Pk2g5SwVNSizwecbELyA+0BrZ9OlRf c44lgZ9cQyxV1trcDOYlBWpzC1XGBgdp7LT+VWxJm0FY8eSHuN+Qvl8lsI9FDI4FkxeIQcXDS rthFP3zPRbZNn942ZiAkBOcnBEe0tajPq6GINlKy839j/TkGdwdhsxp5i/zHyY0HeOEfZBKiY dQ8GiaCYMRNthEnz/lSxZAiqjUL215EpJZ03RWdjAS1pecJyqnYSy+1Du42qPhQcJQd9SGR/X YsTWykG99zSWMcxtDQFb5rVnLOK/Zr1Y0ibPg4KgXmWsU/za1R6xIVf25D0Uurc+fiEqc6Nqt UJcW7p6fDiXeXNHETw/uh6tF2i1+khedwzMa4Tzu92FU25n2KVI9ra8nEBuymO9bovJmypWnY 91Kw0Tj5y8nw0oEXi7baNMjpIFxS7l8bHzfBDY49/bsQE3ZgLLDayrujOchaDdVA4hqBWNCqn 2DbeNLW8aA/Orw= Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2022/2/20 22:46, Souptick Joarder wrote: > From: "Souptick Joarder (HPE)" > > Kernel test robot reported below warning -> > fs/btrfs/scrub.c:3439:2: warning: Undefined or garbage value > returned to caller [clang-analyzer-core.uninitialized.UndefReturn] > > Initialize ret to 0. > > Reported-by: kernel test robot > Signed-off-by: Souptick Joarder (HPE) Although the patch is not yet merged, but I have to say, it's a false aler= t. Firstly, the while loop will always get at least one run. Secondly, in that loop, we either set ret to some error value and break, or after at least one find_first_extent_item() and scrub_extent() call, we increase cur_logical and reached the limit of the while loop and exit. So there is no possible routine to leave @ret uninitialized and returned to caller. Thanks, Qu > --- > fs/btrfs/scrub.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c > index 4baa8e43d585..5ca7e5ffbc96 100644 > --- a/fs/btrfs/scrub.c > +++ b/fs/btrfs/scrub.c > @@ -3325,7 +3325,7 @@ static int scrub_simple_mirror(struct scrub_ctx *s= ctx, > const u32 max_length =3D SZ_64K; > struct btrfs_path path =3D {}; > u64 cur_logical =3D logical_start; > - int ret; > + int ret =3D 0; > > /* The range must be inside the bg */ > ASSERT(logical_start >=3D bg->start &&