From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 DE4DA1DE2A1; Mon, 27 Jan 2025 23:27:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738020421; cv=none; b=U3gqCp6CFylUgMe6AspI/nQfsja0tfWGWs13tZM2k3Ju4v59Ht3oCJPIU1GHuPEKxRSEKiEMmif1k9/m6ekVc08ZG7FodLPXdhPqdSJ9JbXbZPK6b9Ys1elYnEAf3J86jyW94HbxZpfHWrhPGUs5JVIwpNF2MsmaxsbwaGh4m+4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738020421; c=relaxed/simple; bh=yPxfPWU2BE5UFFvv5J6KgISjFCHnr7rGzrI/NdnSLAA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=l9277W6U+BvU+oydsR2KQ4SzMeuZZr/wjQkDyooZ2bXSFN45/IU2I5fMgo30gdw7bNvEyun+zUTmyGl3++l29Xqynzl9N6twVarhpIcjMsK/tPYCNlg1FhnH+B12G2J6aPzLHu/7PSSKYQgBJyqs2JakDga4xvd1frXpkJbB03s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pyzS5Rt1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="pyzS5Rt1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24491C4CED2; Mon, 27 Jan 2025 23:27:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738020420; bh=yPxfPWU2BE5UFFvv5J6KgISjFCHnr7rGzrI/NdnSLAA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=pyzS5Rt1fFT4xwdWOUYXrb+FVdsbGR939Xvk96LURV33REYJyHy9fNRvheAuzm53K zgNioPdB6YTQYyf1reYd3P3ldcX6zBsm0GRpxTbJ7EwocJrNkpyxCdgmnvcNp3DfHL pWRxHuAXP7QyELg5EgRqMdiRRGsduAOMCHUwfbo2tOhBXoZUZtiCA1Vkl4IlQEPV0u wxs9ChXC23X87a0L4q27w8FxmHHhwbNX1IUKrRFN07cOpAp1en1lLZFdY5jD02MVls /S1xXEa4jcTs4cMUtBcaSjrG3/ESTm1gjByrVz13O+S9iOXnpxpIla793yjOGXgxYT pv0z69B8n4Qww== Date: Mon, 27 Jan 2025 18:26:58 -0500 From: Sasha Levin To: Al Viro Cc: Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [git pull] d_revalidate pile Message-ID: References: <20250127044721.GD1977892@ZenIV> <20250127173634.GF1977892@ZenIV> <20250127213456.GH1977892@ZenIV> <20250127224059.GI1977892@ZenIV> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20250127224059.GI1977892@ZenIV> On Mon, Jan 27, 2025 at 10:40:59PM +0000, Al Viro wrote: >On Mon, Jan 27, 2025 at 09:34:56PM +0000, Al Viro wrote: > >> If so, then >> a) it's a false positive (and IIRC, it's not the first time >> kfence gets confused by that) >> b) your bisection will probably converge to bdd9951f60f9 >> "dissolve external_name.u into separate members" which is where we'd >> ended up with offsetof(struct external_name, name) being 4 modulo 8. >> >> As a quick test, try to flip the order of head and count in >> struct external_name and see if that makes the warning go away. >> If it does, I'm pretty certain that theory above is correct. > >Not quite... dentry_string_cmp() assumes that ->d_name.name is >word-aligned, so load_unaligned_zeropad() is done only to the >second string (the one we compare against). Sorry for the silence on my end: this issue doesn't reproduce consistently, so I need to do more runs for these tests. -- Thanks, Sasha