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,URIBL_BLOCKED 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 50CD0C43331 for ; Fri, 3 Apr 2020 09:11:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1039720787 for ; Fri, 3 Apr 2020 09:11:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="UkkQE2BY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390452AbgDCJLl (ORCPT ); Fri, 3 Apr 2020 05:11:41 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:56004 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727635AbgDCJLk (ORCPT ); Fri, 3 Apr 2020 05:11:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585905100; 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=dF3+ctXKfP325/PTZukd3/+N81P9zSwSKiKuEMFAQio=; b=UkkQE2BYez1a0lGknX3ysTpoRpzA0qC+LWDLHu8V0BXuAuRRjEFfNhz2zDv870Lyg7O9AY rTzsw75mG1Szb2hpSmjoMVoeUQV5FNSYWMYwvmWpj/qH3BCUxqccRCHFuUyNVm0NBed+CC 3Ouk9JIjnQil3zzmlJD+nas1lYkyQdM= 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-345-jyX_pzL0PguTukUJevsVaQ-1; Fri, 03 Apr 2020 05:11:37 -0400 X-MC-Unique: jyX_pzL0PguTukUJevsVaQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id BDCC8801A04; Fri, 3 Apr 2020 09:11:34 +0000 (UTC) Received: from ws.net.home (unknown [10.40.194.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 737AF9A24F; Fri, 3 Apr 2020 09:11:28 +0000 (UTC) Date: Fri, 3 Apr 2020 11:11:24 +0200 From: Karel Zak To: Miklos Szeredi Cc: David Howells , Christian Brauner , Linus Torvalds , Al Viro , dray@redhat.com, Miklos Szeredi , Steven Whitehouse , Jeff Layton , Ian Kent , andres@anarazel.de, keyrings@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Lennart Poettering , Aleksa Sarai Subject: Re: Upcoming: Notifications, FS notifications and fsinfo() Message-ID: <20200403091124.zxo7cckcvygzwvgl@ws.net.home> References: <20200330211700.g7evnuvvjenq3fzm@wittgenstein> <1445647.1585576702@warthog.procyon.org.uk> <2418286.1585691572@warthog.procyon.org.uk> <20200401090445.6t73dt7gz36bv4rh@ws.net.home> <2488530.1585749351@warthog.procyon.org.uk> <2488734.1585749502@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 01, 2020 at 05:25:54PM +0200, Miklos Szeredi wrote: > fsinfo(2) will never be substantially cheaper than reading and parsing > /mnt/MNT_ID/info. In fact reading a large part of the mount table > using fsinfo(2) will be substantially slower than parsing > /proc/self/mountinfo (this doesn't actually do the parsing but that > would add a very small amount of overhead): I think nobody wants to use fsinfo() or mountfs as replacement to whole /proc/self/mountinfo. It does not make sense. We need per-mountpoint API, for whole mount table use-cases (like findmnt or lsblk) the current mountinfo is good enough. Karel -- Karel Zak http://karelzak.blogspot.com