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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 0E186C433E0 for ; Wed, 24 Jun 2020 05:37:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2EA020768 for ; Wed, 24 Jun 2020 05:37:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592977056; bh=wb4QukjekILuiNOvt3WtAggRANvs3/DPlF6kk/OZN9A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=17RXRVsTjIZeJYIs9TUoL5Z+gCQ0RtEJF5eTSMYSrVDrvjgPyGXug4+jzLSoVHrIe sJ/o4FQ5vZpGVxhEvBIta15gvJJhCx3QRsX86rhrSKavwCsbaZEjNljKShlMsY7DRa X6dNOGufAK1uJWi5H8ZlRW5LCVi3io89gd2bQTGg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388861AbgFXFhc (ORCPT ); Wed, 24 Jun 2020 01:37:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:54570 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388470AbgFXFhb (ORCPT ); Wed, 24 Jun 2020 01:37:31 -0400 Received: from sol.localdomain (c-107-3-166-239.hsd1.ca.comcast.net [107.3.166.239]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DC0C82072E; Wed, 24 Jun 2020 05:37:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592977051; bh=wb4QukjekILuiNOvt3WtAggRANvs3/DPlF6kk/OZN9A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ME2/ILyRl01EO6yDPEjuIw5z41jE6WT0YL/dZxeFp1FPcCqTGoXmWlZASWXMdQg+d Gg6ZXHBJaopVsT69BCF292QvgQpMxHWYMvgoHHUbOyO2xDDrO8HZyvDEPplfoZjCZF oVsC9NaAewstXOI+yLeiPyQ9MDInXF4S2T12EQBY= Date: Tue, 23 Jun 2020 22:37:29 -0700 From: Eric Biggers To: Daniel Rosenberg Cc: Theodore Ts'o , linux-ext4@vger.kernel.org, Jaegeuk Kim , Chao Yu , linux-f2fs-devel@lists.sourceforge.net, linux-fscrypt@vger.kernel.org, Alexander Viro , Richard Weinberger , linux-mtd@lists.infradead.org, Andreas Dilger , Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Gabriel Krisman Bertazi , kernel-team@android.com Subject: Re: [PATCH v9 1/4] unicode: Add utf8_casefold_hash Message-ID: <20200624053729.GE844@sol.localdomain> References: <20200624043341.33364-1-drosen@google.com> <20200624043341.33364-2-drosen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200624043341.33364-2-drosen@google.com> Sender: linux-fscrypt-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fscrypt@vger.kernel.org On Tue, Jun 23, 2020 at 09:33:38PM -0700, Daniel Rosenberg wrote: > This adds a case insensitive hash function to allow taking the hash > without needing to allocate a casefolded copy of the string. It would be helpful to add a few more details in this commit message. Somewhat along the lines of: ->d_hash() for casefolding currently allocates memory, it needs to use GFP_ATOMIC due to ->d_hash() being called in rcu-walk mode, this is unreliable and inefficient, and this patch allows solving that problem by removing the need to allocate memory. - Eric