Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966918AbXEGVBT (ORCPT ); Mon, 7 May 2007 17:01:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S966639AbXEGVBR (ORCPT ); Mon, 7 May 2007 17:01:17 -0400 Received: from mail.parknet.jp ([210.171.160.80]:4623 "EHLO parknet.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966911AbXEGVBP (ORCPT ); Mon, 7 May 2007 17:01:15 -0400 X-AuthUser: hirofumi@parknet.jp To: Roland Kuhn Cc: Andrey Borzenkov , linux-kernel@vger.kernel.org Subject: Re: Long file names in VFAT broken with iocharset=utf8 References: <200705072151.20104.arvidjaar@mail.ru> <60F72760-C801-4F60-BF47-C661B4B5BE26@e18.physik.tu-muenchen.de> <87fy685w0m.fsf@duaron.myhome.or.jp> From: OGAWA Hirofumi Date: Tue, 08 May 2007 06:01:07 +0900 In-Reply-To: (Roland Kuhn's message of "Mon\, 7 May 2007 21\:59\:15 +0200") Message-ID: <877irk5ox8.fsf@duaron.myhome.or.jp> User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.1.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1613 Lines: 33 Roland Kuhn writes: >> Roland Kuhn writes: >>> PATH_MAX specifically counts _bytes_ not characters, so UTF-8 does >>> not matter. ISTR that PATH_MAX was 256 at some point, but I just >>> quickly grepped /usr/include and found various mention of 4096, so >>> where's the central repository for this configuration item? A hard- >>> coded value of 256 somewhere inside the kernel smells like a bug. >> >> There is a nasty issue here. FAT is limited by 255 unicode chars or >> so. >> So, we would need to count number of unicode chars of filename. >> > No, we don't. At least not when looking at the POSIX spec, which > explicitly mentions _bytes_ and _not_ unicode characters. So, to be > on the safe side, FAT filesystems would need to support a NAME_MAX of > roughly 6*255+3=1533 bytes (not to mention the hassles of forbidden > sequences, etc.; do we need to count zero-width characters?) and > report it through pathconf() to userspace, then userspace could do > with that whatever it liked. > > What happened to: "file names are just sequences of octets, excluding > '/' and UL"? Adding unicode parsing to the kernel is completely > useless _and_ a big trouble maker. The UCS2 in FAT is just on-disk format of the filename. So... -- OGAWA Hirofumi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/