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 Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7E57FC61D88 for ; Tue, 21 Nov 2023 02:17:27 +0000 (UTC) Received: from [127.0.0.1] (helo=sfs-ml-2.v29.lw.sourceforge.com) by sfs-ml-2.v29.lw.sourceforge.com with esmtp (Exim 4.95) (envelope-from ) id 1r5GKL-0005lk-R4; Tue, 21 Nov 2023 02:17:24 +0000 Received: from [172.30.20.202] (helo=mx.sourceforge.net) by sfs-ml-2.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1r5GKH-0005lR-7k for linux-f2fs-devel@lists.sourceforge.net; Tue, 21 Nov 2023 02:17:20 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=In-Reply-To:Content-Transfer-Encoding:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=RI/R/dL+OK3InX9FiqKDXHPEN021Sx3jNB6FQIcl/vA=; b=DX1Dr+zHBZaNUti8n92FfmmFXn QhmSkH19AA8q/mt661X3W3VfvMfcEsVb1dhMt/oJSSb71IgfdpQqWKk706ceZ/GYzWa97Ag8UYbNx 9KwPUDRt6vi258r6YntJ3duxlAzsXFkSP6HvMTSreMTsJ9ylbB815GK1asXCFZBgBHgw=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=In-Reply-To:Content-Transfer-Encoding:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=RI/R/dL+OK3InX9FiqKDXHPEN021Sx3jNB6FQIcl/vA=; b=hvS/o84Y0japeVqV3YCVx1rP06 NoRaECGBIcFF47rS+RHIx9Gd15Wi+EkaJuILAXDXmeZd78Qo+gd2ZLaJuWUbVPJd826nKJIr0ggel QC21mCroBrlI+DE4VYxiNypTQ5QeoKQsTYGJSJgPnZUJ/AiUu4kTKU1PsOSVgJpAWxiM=; Received: from outgoing-auth-1.mit.edu ([18.9.28.11] helo=outgoing.mit.edu) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.95) id 1r5GKD-0004JQ-Bm for linux-f2fs-devel@lists.sourceforge.net; Tue, 21 Nov 2023 02:17:19 +0000 Received: from cwcc.thunk.org (pool-173-48-82-21.bstnma.fios.verizon.net [173.48.82.21]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id 3AL22s5b004315 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 20 Nov 2023 21:02:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mit.edu; s=outgoing; t=1700532178; bh=RI/R/dL+OK3InX9FiqKDXHPEN021Sx3jNB6FQIcl/vA=; h=Date:From:Subject:Message-ID:MIME-Version:Content-Type; b=fh+Iz59mAaEhYI6Rnl1Ws5eNRCdm8wGGiPBNrtSex6iEN3evmaEE4VQ38o7HziJIX 1oE53Yx5gx4QD+4kGuf0DRlqTlOmzTWeEI2U3lwozuid2nmQUf3gYQ2cFfVX58ObIS AOF5SVofHZTGGj/d41vBKcNaXkE103Uvrh87PK5pi0LdMGHs5Xqj6zMO4rTyX9usd9 drGCCLumglHiyBKsUPqRzlaLSTktuNh3kOnfULa7loj6SCmki5AcJ9s3b1I/ItdyGj OJ8dmIFQVzZuLCX6BAwNAawsKR4kbHK+H0hmI1SBGThTTmsfe2NgCjRISca5zfG2+N +bR7dioZFi29A== Received: by cwcc.thunk.org (Postfix, from userid 15806) id A86F715C02B0; Mon, 20 Nov 2023 21:02:54 -0500 (EST) Date: Mon, 20 Nov 2023 21:02:54 -0500 From: "Theodore Ts'o" To: Linus Torvalds Message-ID: <20231121020254.GB291888@mit.edu> References: <20230816050803.15660-1-krisman@suse.de> <20231025-selektiert-leibarzt-5d0070d85d93@brauner> <655a9634.630a0220.d50d7.5063SMTPIN_ADDED_BROKEN@mx.google.com> <20231120-nihilismus-verehren-f2b932b799e0@brauner> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Headers-End: 1r5GKD-0004JQ-Bm Subject: Re: [f2fs-dev] [PATCH v6 0/9] Support negative dentries on case-insensitive ext4 and f2fs X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gabriel Krisman Bertazi , Christian Brauner , linux-f2fs-devel@lists.sourceforge.net, ebiggers@kernel.org, viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org, jaegeuk@kernel.org, linux-ext4@vger.kernel.org Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net On Mon, Nov 20, 2023 at 10:07:51AM -0800, Linus Torvalds wrote: > Of course, "do it in shared generic code" doesn't tend to really fix > the braindamage, but at least it's now shared braindamage and not > spread out all over. I'm looking at things like > generic_ci_d_compare(), and it hurts to see the mindless "let's do > lookups and compares one utf8 character at a time". What a disgrace. > Somebody either *really* didn't care, or was a Unicode person who > didn't understand the point of UTF-8. This isn't because of case-folding brain damage, but rather Unicode brain damage. We compare one character at a time because it's possible for some character like =E9 to either be encoded as 0x0089 (aka "Latin Small Letter E with Acute") OR as 0x0065 0x0301 ("Latin Small Letter E" plus "Combining Acute Accent"). Typically, we pretend that UTF-8 means that we can just encode =E9, or 0x0089 as 0xC3 0xA9 and then call it a day and just use strcmp(3) on the sucker. But Unicode is a lot more insane than that. Technically, 0x65 0xCC 0x81 is the same character as 0xC3 0xA9. > Oh well. I guess people went "this is going to suck anyway, so let's > make sure it *really* sucks". It's more like, "this is going to suck, but if it's going to suck anyway, let's implement the full Unicode spec in all its gory^H^H^H^H glory, whether or not it's sane". - Ted _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel