[{"id":3684292,"web_url":"http://patchwork.ozlabs.org/comment/3684292/","msgid":"<3d3d6e22-b8a7-4f32-8046-697e45ec6c04@dev.snart.me>","list_archive_url":null,"date":"2026-04-29T22:00:04","subject":"Re: [PATCH v12 04/15] exfat: Implement fileattr_get for case\n sensitivity","submitter":{"id":92763,"url":"http://patchwork.ozlabs.org/api/people/92763/","name":"David Timber","email":"dxdt@dev.snart.me"},"content":"On 4/30/26 03:07, Chuck Lever wrote:\n> From: Chuck Lever \n>\n> Report exFAT's case sensitivity behavior via the FS_XFLAG_CASEFOLD\n> flag. exFAT is always case-insensitive (using an upcase table for\n> comparison) and always preserves case at rest.\nNot necessarily \"always\".\n\nLink: https://github.com/exfatprogs/exfatprogs/issues/313\n\nThe specs(SD spec part 2 and MS spec) leave it up to the formatter\nimplementation on how the volume should behave. The observed behaviour\nis that it is quite flexible: you can pretty much use any artitrary\nup-case table to make an exFAT volume behave completely different and\nmajor implementations including Linux and Windows kernel honour the\ntable no matter what. So exFAT is not so \"binary\"(folding vs. not\nfolding) when it comes to case folding behaviour.\n\nNTFS also has a similar up-case table feature. Although it's usually\nunused, if an up-case table exists in the volume, the implementation\nprobably has to honour it(although this is not written down in any spec,\nthis should be the expectation).\n\nAt the end of the day, it wouldn't matter much because no sane formatter\nwould produce a volume with some weird version up-case table. But if\nthat attribute plays a important role in some system that has some level\nof impact, I suggest considering another attribute, say \"unknown\" or \"it\ndepends\".\n\nDavo","headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-cifs@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=172.105.105.114; helo=tor.lore.kernel.org;\n envelope-from=linux-cifs+bounces-11302-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=54.252.183.203","smtp.subspace.kernel.org;\n dmarc=pass (p=reject dis=none) header.from=dev.snart.me","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=dev.snart.me"],"Received":["from tor.lore.kernel.org (tor.lore.kernel.org [172.105.105.114])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519 server-signature ECDSA (secp384r1) server-digest SHA384)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4g5WT101vHz1yGq\n\tfor ; Thu, 30 Apr 2026 08:00:36 +1000 (AEST)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby tor.lore.kernel.org (Postfix) with ESMTP id 27C0F300AC3B\n\tfor ; Wed, 29 Apr 2026 22:00:19 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 4BD1E1DD877;\n\tWed, 29 Apr 2026 22:00:17 +0000 (UTC)","from embla.dev.snart.me (embla.dev.snart.me [54.252.183.203])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 07A1F26A0D5;\n\tWed, 29 Apr 2026 22:00:15 +0000 (UTC)","from embla.dev.snart.me (localhost [IPv6:::1])\n\tby embla.dev.snart.me (Postfix) with ESMTP id A21F41D459;\n\tWed, 29 Apr 2026 22:00:08 +0000 (UTC)","from [192.168.1.18] ([182.226.25.243])\n\tby embla.dev.snart.me with ESMTPSA\n\tid nLFlEmh/8mm4swUA8KYfjw\n\t(envelope-from ); Wed, 29 Apr 2026 22:00:08 +0000"],"ARC-Seal":"i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116;\n\tt=1777500017; cv=none;\n b=TkXSbGTEP3Q96Eem73vwl8DHpgNmrDUJJCIq0al6DYbT/hmhsBm/S7wM6XUBeAppMYVsNBlYM0GFKsqoC+iM2WZ9AjuoyHGXMk0BpStIB5kuMUbpEXBsj1EAogr5+fm683NetL128jBeDYZUJSlKlNCMLOxpZFazaYynVvNiNv4=","ARC-Message-Signature":"i=1; a=rsa-sha256; d=subspace.kernel.org;\n\ts=arc-20240116; t=1777500017; c=relaxed/simple;\n\tbh=Q+hGRNt4Qu8Kg28XQ4VG6Co93Cs9xCHkhw8gVF9vba8=;\n\th=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From:\n\t In-Reply-To:Content-Type;\n b=ijO6EVkaXfDm4eWzVyAbBhx8hz2A2E7j37JeETC94bIXLQPEH6yHeiQOgnbvVdiaRiXkM9x2jqjdaKsBJky+8+L5ZDhB58F605IgYZa+7CLHGDcs33MxQj2XFqbUlP5gYBdyHkVcnGS18+SAm8yJbH9QcW0sYI/Igp6FDCmDM5E=","ARC-Authentication-Results":"i=1; smtp.subspace.kernel.org;\n dmarc=pass (p=reject dis=none) header.from=dev.snart.me;\n spf=pass smtp.mailfrom=dev.snart.me; arc=none smtp.client-ip=54.252.183.203","Message-ID":"<3d3d6e22-b8a7-4f32-8046-697e45ec6c04@dev.snart.me>","Date":"Thu, 30 Apr 2026 07:00:04 +0900","Precedence":"bulk","X-Mailing-List":"linux-cifs@vger.kernel.org","List-Id":"","List-Subscribe":"","List-Unsubscribe":"","MIME-Version":"1.0","User-Agent":"Mozilla Thunderbird","Subject":"Re: [PATCH v12 04/15] exfat: Implement fileattr_get for case\n sensitivity","To":"Chuck Lever , Al Viro ,\n Christian Brauner , Jan Kara ","Cc":"linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org,\n linux-xfs@vger.kernel.org, linux-cifs@vger.kernel.org,\n linux-nfs@vger.kernel.org, linux-api@vger.kernel.org,\n linux-f2fs-devel@lists.sourceforge.net, hirofumi@mail.parknet.co.jp,\n linkinjeon@kernel.org, sj1557.seo@samsung.com, yuezhang.mo@sony.com,\n almaz.alexandrovich@paragon-software.com, slava@dubeyko.com,\n glaubitz@physik.fu-berlin.de, frank.li@vivo.com, tytso@mit.edu,\n adilger.kernel@dilger.ca, cem@kernel.org, sfrench@samba.org,\n pc@manguebit.org, ronniesahlberg@gmail.com, sprasad@microsoft.com,\n trondmy@kernel.org, anna@kernel.org, jaegeuk@kernel.org, chao@kernel.org,\n hansg@kernel.org, senozhatsky@chromium.org,\n Chuck Lever , Roland Mainz ","References":"<20260429-case-sensitivity-v12-0-8057123bebe0@oracle.com>\n <20260429-case-sensitivity-v12-4-8057123bebe0@oracle.com>","From":"David Timber ","Content-Language":"en-US, ko","Autocrypt":"addr=dxdt@dev.snart.me; keydata=\n xjMEYmJg1hYJKwYBBAHaRw8BAQdAf5E+ri1XLtjqYbZdHOyc8oS+1/XJ5bSlbx5WHXmVBZzN\n IERhdmlkIFRpbWJlciA8ZHhkdEBkZXYuc25hcnQubWU+wpQEExYKADwWIQQn/Jn96EMUaIoF\n X+T/ldyyrZpWaAUCYmJg1gIbAwULCQgHAgMiAgEGFQoJCAsCBBYCAwECHgcCF4AACgkQ/5Xc\n sq2aVmjJZwD8COjPlUwccrlRvbNQ6f87DWchtYO0o8W2DNRM3RLps0EA/jEhIbRV6AsyC8jr\n 30Ut3aJ3/mO/6G4sLj7OvkEEBH0MzjgEYmJg1hIKKwYBBAGXVQEFAQEHQFpgtIgaByv9lIEY\n EmpavMO0pYjtu7TMJynwdnGYkN9LAwEIB8J4BBgWCgAgFiEEJ/yZ/ehDFGiKBV/k/5Xcsq2a\n VmgFAmJiYNYCGwwACgkQ/5Xcsq2aVmhFCwEA0kM9VyYB4bLCM7+SuXUUH+5Ec99Nj4RXxFad\n Key9GuwA/2BZK6bNyrLSfEk2JDRoskqf7OIL0wa6JOD5SrBnMe8E","In-Reply-To":"<20260429-case-sensitivity-v12-4-8057123bebe0@oracle.com>","Content-Type":"text/plain; charset=UTF-8","Content-Transfer-Encoding":"7bit"}}]