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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 BB359C67790 for ; Fri, 27 Jul 2018 23:49:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 75D6820647 for ; Fri, 27 Jul 2018 23:49:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 75D6820647 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389145AbeG1BNO (ORCPT ); Fri, 27 Jul 2018 21:13:14 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:38028 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388527AbeG1BNO (ORCPT ); Fri, 27 Jul 2018 21:13:14 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 27A9E738EF; Fri, 27 Jul 2018 23:49:02 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-116.rdu2.redhat.com [10.10.120.116]) by smtp.corp.redhat.com (Postfix) with ESMTP id 26D8A21568A1; Fri, 27 Jul 2018 23:49:01 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <153271267980.9458.7640156373438016898.stgit@warthog.procyon.org.uk> <153271291017.9458.7827028432894772673.stgit@warthog.procyon.org.uk> To: Jann Horn Cc: dhowells@redhat.com, Al Viro , Linux API , Linus Torvalds , linux-fsdevel@vger.kernel.org, kernel list Subject: Re: [PATCH 34/38] vfs: syscall: Add fsinfo() to query filesystem information [ver #10] MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <21394.1532735340.1@warthog.procyon.org.uk> Date: Sat, 28 Jul 2018 00:49:00 +0100 Message-ID: <21395.1532735340@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 27 Jul 2018 23:49:02 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.1]); Fri, 27 Jul 2018 23:49:02 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'dhowells@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jann Horn wrote: > > +static int fsinfo_generic_name_encoding(struct dentry *dentry, char *buf) > > +{ > > + static const char encoding[] = "utf8"; > > + > > + if (buf) > > + memcpy(buf, encoding, sizeof(encoding) - 1); > > + return sizeof(encoding) - 1; > > +} > > Is this meant to be "encoding to be used by userspace" or "encoding of > on-disk filenames"? The latter. > Are there any plans to create filesystems that behave differently? isofs, fat, ntfs, cifs for example. > If the latter: This is wrong for e.g. a vfat mount that uses a codepage, > right? Should the default in that case not be "I don't know"? Quite possibly. Note that it could also be what you're interpreting it as because the codepage got overridden by a mount parameter rather than what's on the disk (assuming the medium actually records this). One thing I'm confused about is that fat has both a codepage and a charset and I'm not sure of the difference. David