From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from outgoing.mit.edu (outgoing-auth-1.mit.edu [18.9.28.11]) (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 7455A1758E for ; Tue, 2 Apr 2024 03:55:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=18.9.28.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712030148; cv=none; b=EW/uSK7rPsLhYHvmxqxKtOFXHrN5UWb+OaeErl3t8VvKfSFtUT96AJgWNe3cySfbTBZB325AQBr/3rGwo05u8Vs12+aCygZ8vIOERL9scXrFOeOUBBjHfOgKkf42ni4xI5k3d2N9TUKnSa06MnbGpMu2/CTS9DHdXwSCsBXeQuI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712030148; c=relaxed/simple; bh=Ovu1Zl+lRgprOnzlsNT9/gVbAYFDS0biN7y4UFFEcHU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=fNmEw1EzYD7s1uZ0tLY+2y5ipdbAeLmTOR+GcQtAuHGj+EaiN/vERqVdjN4G/MYZM+NlGieBzanUhOL864VwW76DMABr+3G1McXL1dMCEzrgOej8omqMwBczNl6FnShN5pqQ7xRJGvUxXId29EMPlhRcGm8v+JgqMmzPNNRp+ro= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu; spf=pass smtp.mailfrom=mit.edu; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b=mlNKUkcH; arc=none smtp.client-ip=18.9.28.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mit.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mit.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mit.edu header.i=@mit.edu header.b="mlNKUkcH" Received: from cwcc.thunk.org (pool-173-48-113-232.bstnma.fios.verizon.net [173.48.113.232]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 4323tZ1X028188 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 1 Apr 2024 23:55:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1712030137; bh=W9AENbMZ6T30aoSARNRXwRAqIqETtvwIKmOEx7j/tuY=; h=Date:From:Subject:Message-ID:MIME-Version:Content-Type; b=mlNKUkcHa8imT+MUvtaDgSMiaAu2/xGV4g52aaStjZY8Nw1CwonKD26oTyR3hX48T 9mAJLdZmns97uBXH4lxd+NOW4QFScUDx/iDZIyzoKps4yGPd3fZAp+7VScuhbUHXqu nIU+HxTCv6yR+ZR67bfgmASjrIKh6NH0ueofbRN6D8fd1NLKS2ggDEYAGeVlgwGD/f +5/Q5gW0A50GnfO9htePeNKDo7xoCW1VEXIBF51zjgdaueZ4y09HAYUT/UJrjx6pgG Erx/NRv//OAmc65/XeKDfkHLFdwDVUJ5/UzHus4jnb6uQXUdoVGKMzj04zS9s2sduz pRfXKtNCcm85A== Received: by cwcc.thunk.org (Postfix, from userid 15806) id 1642A15C00DC; Mon, 1 Apr 2024 23:55:35 -0400 (EDT) Date: Mon, 1 Apr 2024 23:55:35 -0400 From: "Theodore Ts'o" To: Li zeming Cc: adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ext4: extents: =?utf-8?Q?Remov?= =?utf-8?B?ZSB1bm5lY2Vzc2FyeSDigJhOVUxM4oCZ?= values from ablocks Message-ID: <20240402035535.GD1189142@mit.edu> References: <20240402024804.29411-1-zeming@nfschina.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240402024804.29411-1-zeming@nfschina.com> On Tue, Apr 02, 2024 at 10:48:04AM +0800, Li zeming wrote: > ablocks is assigned first, so it does not need to initialize the > assignment. That's technically true, but the compiler is perfectly capable of optimizing it out. So it's harmless, and removing it does make the code a bit more fragile, since it needs to be set so that the cleanup code doesn't accidentally dereference an uninitialized pointer. Cheers, - Ted