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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 BD04CC11D07 for ; Thu, 20 Feb 2020 12:22:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9418724656 for ; Thu, 20 Feb 2020 12:22:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="UWb9yP5p" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727964AbgBTMWR (ORCPT ); Thu, 20 Feb 2020 07:22:17 -0500 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:26712 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726921AbgBTMWR (ORCPT ); Thu, 20 Feb 2020 07:22:17 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582201336; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Sgne7vEZYUlNT6R014gNlgb5JFShF1C38DgPIAIxt3w=; b=UWb9yP5pvcl6LRmgc+Z7lh6XPQb4U83KhT/z5UCaz87pWCPiyzdJQ4Nt815NpyXsI+aSua UgIzDd4BVByPQxznXCcu5c9NMUrFprSyK9uJSCxup39A78GtkfjTgMqqHc2Ef1BYHLS0hy PEU5rVLsY0m3yE0V1jFmk/DB5jFlBI4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-369-rleZgANVOiu2qcgllCao9w-1; Thu, 20 Feb 2020 07:22:13 -0500 X-MC-Unique: rleZgANVOiu2qcgllCao9w-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BE29318C35A1; Thu, 20 Feb 2020 12:22:11 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-122-163.rdu2.redhat.com [10.10.122.163]) by smtp.corp.redhat.com (Postfix) with ESMTP id CF5E819C4F; Thu, 20 Feb 2020 12:22:09 +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: <20200219163705.GC9496@magnolia> References: <20200219163705.GC9496@magnolia> <158204549488.3299825.3783690177353088425.stgit@warthog.procyon.org.uk> <158204552063.3299825.17824500635078230412.stgit@warthog.procyon.org.uk> To: "Darrick J. Wong" Cc: dhowells@redhat.com, viro@zeniv.linux.org.uk, raven@themaw.net, mszeredi@redhat.com, christian@brauner.io, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 03/19] fsinfo: Provide a bitmap of supported features [ver #16] MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <596566.1582201328.1@warthog.procyon.org.uk> Date: Thu, 20 Feb 2020 12:22:08 +0000 Message-ID: <596567.1582201328@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Darrick J. Wong wrote: > > +struct fsinfo_features { > > + __u8 features[(FSINFO_FEAT__NR + 7) / 8]; > > Hm...the structure size is pretty small (56 bytes) and will expand as we > add new _FEAT flags. Is this ok because the fsinfo code will truncate > its response to userspace to whatever buffer size userspace tells it? Yes. Also, you can ask fsinfo how many feature bits it supports. I should put this in the struct first rather than putting it elsewhere. David