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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE843C433EF for ; Fri, 25 Mar 2022 09:11:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356339AbiCYJMg (ORCPT ); Fri, 25 Mar 2022 05:12:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229940AbiCYJMc (ORCPT ); Fri, 25 Mar 2022 05:12:32 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id EB1BCCF486 for ; Fri, 25 Mar 2022 02:10:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1648199458; 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=QMxMPmZqVhEjq+z25uJtmZ8oxGgfdMtdpHWVpm7w/Uk=; b=WaUy2THuFWrMT/njrmlI7YM47hkMnMHVM8nd8EnyUQNVnMBB3A4wwWVp8y8ELfyUEhOQOS h7OdHpsPg06z1xHdxWXN9a5yOSD5Y8pAd2UHGJ5lH0LEccAU6vl9H7CIZfsknZ768aQIow PQ8Dk8M/rn4pbiU+KRMGEc2P53zNgPg= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-385-thh7RGY_OnqkbS7LlDlomg-1; Fri, 25 Mar 2022 05:10:54 -0400 X-MC-Unique: thh7RGY_OnqkbS7LlDlomg-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id DD6E71C06923; Fri, 25 Mar 2022 09:10:53 +0000 (UTC) Received: from ws.net.home (unknown [10.36.112.12]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B905E141DED5; Fri, 25 Mar 2022 09:10:51 +0000 (UTC) Date: Fri, 25 Mar 2022 10:10:49 +0100 From: Karel Zak To: Dave Chinner Cc: Miklos Szeredi , Miklos Szeredi , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Linux API , linux-man , LSM , Ian Kent , David Howells , Linus Torvalds , Al Viro , Christian Brauner , Amir Goldstein , James Bottomley Subject: Re: [RFC PATCH] getvalues(2) prototype Message-ID: <20220325091049.b5vcfahti56hopy2@ws.net.home> References: <20220322192712.709170-1-mszeredi@redhat.com> <20220323225843.GI1609613@dread.disaster.area> <20220324203116.GJ1609613@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220324203116.GJ1609613@dread.disaster.area> X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 25, 2022 at 07:31:16AM +1100, Dave Chinner wrote: > > What about other objects' attributes, statistics? Remember this > > started out as a way to replace /proc/self/mountinfo with something > > that can query individual mount. > > For individual mount info, why do we even need to query something in > /proc? I mean, every open file in the mount has access to the mount > and the underlying superblock, so why not just make the query > namespace accessable from any open fd on that mount? The current most problematic situation is in systemd. We get generic notification (poll() on mountinfo) that something has been modified in the mount table, and then we need to parse all the file to get details. So, the ideal solution would be notification that points to the FS and interface to read information (e.g. getvalues()) about the FS. Karel -- Karel Zak http://karelzak.blogspot.com