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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable 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 9ACB9C282C7 for ; Wed, 30 Jan 2019 02:44:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 659F720870 for ; Wed, 30 Jan 2019 02:44:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=themaw.net header.i=@themaw.net header.b="cjkx6i/t"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="cK5Zx94N" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729925AbfA3CoX (ORCPT ); Tue, 29 Jan 2019 21:44:23 -0500 Received: from wout2-smtp.messagingengine.com ([64.147.123.25]:36819 "EHLO wout2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729718AbfA3CoX (ORCPT ); Tue, 29 Jan 2019 21:44:23 -0500 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailout.west.internal (Postfix) with ESMTP id AD6661719; Tue, 29 Jan 2019 21:44:21 -0500 (EST) Received: from mailfrontend1 ([10.202.2.162]) by compute1.internal (MEProxy); Tue, 29 Jan 2019 21:44:22 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=themaw.net; h= message-id:subject:from:to:cc:date:in-reply-to:references :content-type:mime-version:content-transfer-encoding; s=fm2; bh= Gc6FHnmci9DMdKktV5Xl7cyp+gzcAF5J3MrudSjp00c=; b=cjkx6i/tn2+/LNgN oTWKlrBmSdZbUbsT8CQIaZ3z7O/TNfcINaCjAfGOFWVKVxxTZWYG1QPQh0M7xQZv 5gbYo+jpu36+zYFYo1IKadWsRlo+dKvyXmxRf844vYukcv112QGw2QVbyYk7Qqgl pF2XILyom2W2fjRjunCD7Ri2s8AKi3GktSBeuCRTlKkOeAGoT2bVrxlaK5fmsTHn bjF4Fq8M576YuLyGj+kQof4kmPDgKBT5rgjub4ZA1hFGritPvVyTEg48BBjOwVd0 Z9KzovBULNGE+tN1YKNvFB3Lpzu4mLp0PjUd8Q04WnCMAOjwiYKU7aF4hn1GcwVV vAIchw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm1; bh=Gc6FHnmci9DMdKktV5Xl7cyp+gzcAF5J3MrudSjp0 0c=; b=cK5Zx94NYH5L5QtVUGUQBmnXqEkXJmNXpXp6N4rKgX6FS9Bq2POZdEFLE wf0BraNJssbHycx6lhLSScVGetMnDung+SaV4ngEt8GY3GndvVoKt07PYYyD5urG 26tjoRkUTuOk8nQyHK4zXxlsgi1uue5cA+5LEoiRCYfOMKh4O45hEX9ImkK34g9d UUfY5rVUrFpJRByNZyk8Xe4nBLP8RzbQjyDwoRr8NZljbDnrTz+1v4hsGReARWvl ozK8oy9J0pRTVtR1N2EobD4DTrotVH7gnmbbQWTKsldG3WW7Tw4HUXuV1UW6lubB OIDmv8WXKzM7XsfAe8wfkxkSMlJaw== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedtledrjeefgdehvdcutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfhuthenuceurghilhhouhhtmecufedt tdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepkffuhffvffgjfh gtofgggfesthejredtredtjeenucfhrhhomhepkfgrnhcumfgvnhhtuceorhgrvhgvnhes thhhvghmrgifrdhnvghtqeenucfkphepuddukedrvddtkedrudeijedrheeinecurfgrrh grmhepmhgrihhlfhhrohhmpehrrghvvghnsehthhgvmhgrfidrnhgvthenucevlhhushht vghrufhiiigvpedt X-ME-Proxy: Received: from localhost (unknown [118.208.167.56]) by mail.messagingengine.com (Postfix) with ESMTPA id DB483E41F3; Tue, 29 Jan 2019 21:44:18 -0500 (EST) Message-ID: <804b86df6fd678147da816be038b11c87333b23f.camel@themaw.net> Subject: Re: [PATCH 3/3] autofs: add ignore mount option From: Ian Kent To: Al Viro Cc: autofs mailing list , linux-fsdevel , Kernel Mailing List , Andrew Morton Date: Wed, 30 Jan 2019 10:44:15 +0800 In-Reply-To: <553f4a0daf09407371193d7d4782a759561a626a.camel@themaw.net> References: <154725122396.11260.16053424107144453867.stgit@pluto-themaw-net> <154725123970.11260.6113771566924907275.stgit@pluto-themaw-net> <20190129171622.5b75f794d2b1e4d1055331eb@linux-foundation.org> <553f4a0daf09407371193d7d4782a759561a626a.camel@themaw.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-2.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2019-01-30 at 10:07 +0800, Ian Kent wrote: > On Tue, 2019-01-29 at 17:16 -0800, Andrew Morton wrote: > > On Sat, 12 Jan 2019 08:00:40 +0800 Ian Kent wrote: > > > > > Add an autofs file system mount option that can be used to provide > > > a generic indicator to applications that the mount entry should be > > > ignored when displaying mount information. > > > > What is the reason for adding this feature? > > In other OSes that provide autofs and that provide a mount list > to user space based on the kernel mount list a no-op mount option > ("ignore" is the one use on the most common OS) is allowed so that > autofs file system users can optionally use it. > > The idea is that it be used by user space programs to exclude > autofs mounts from consideration when reading the mounts list. > > Prior to the change to link /etc/mtab to /proc/self/mounts all > I needed to do to achieve this was to use mount(2) and not update > the mtab but now that no longer works. > > I know the symlinking happened a long time ago and I considered > doing this then but, at the time I couldn't remember the commonly > used option name and thought persuading the various utility > maintainers would be too hard. > > But now I have a RHEL request to do this for compatibility for a > widely used product so I want to go ahead with it and try and > enlist the help of some utility package maintainers. Al, On a different note the above request also raised another question about statvfs(3) automount behaviour. In glibc statvfs(3) uses statfs(2) and translates the return to a statvfs structure. I wasn't aware but apparently statvfs(3) (and presumably statfs(2)) doesn't trigger an automount on Solaris whereas we do. I think statfs() is probably the only exception to the convention that stat family system calls don't trigger an automount. So far I've said that this is a long standing behaviour in the Linux kernel and changing it could lead to unpleasant surprises for those that have come to expect this behaviour so such a change would not be well received. But I do need to ask your opinion, so what are your thoughts about changing this? Ian