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=-4.1 required=3.0 tests=BAYES_00,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 8CE8BC433E0 for ; Mon, 3 Aug 2020 12:42:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E0802054F for ; Mon, 3 Aug 2020 12:42:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="O2yqvXo0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729219AbgHCMl7 (ORCPT ); Mon, 3 Aug 2020 08:41:59 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:40476 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729273AbgHCMcD (ORCPT ); Mon, 3 Aug 2020 08:32:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596457922; 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=+FTqyOz+KM8b1l5RbH2zS34D2EqLt9IQI9azf1e1ydg=; b=O2yqvXo0igto70PGbTccw38Nvw+kQKvBUvKy0S/bLEufT+HlS0SCAyJ6cQdvtl6rc3MqFP vHGonZ/MA0O51mYlIihyqjNxA17a9/Z/qbBjuBVW5AD7JczIqHl+HuKwbKP4QgaT0M5V7c a9/LUyfXCO0IzGGyywCGHvR/MNDWdcg= 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-77-YLQh1wy0P0eZHtUDK-Mg4w-1; Mon, 03 Aug 2020 08:31:58 -0400 X-MC-Unique: YLQh1wy0P0eZHtUDK-Mg4w-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B7D55101C8A8; Mon, 3 Aug 2020 12:31:56 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-112-32.rdu2.redhat.com [10.10.112.32]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8724E7176A; Mon, 3 Aug 2020 12:31:53 +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: <303106be4785135446e56cb606138a6e94885887.camel@themaw.net> References: <303106be4785135446e56cb606138a6e94885887.camel@themaw.net> <1293241.1595501326@warthog.procyon.org.uk> <158454378820.2863966.10496767254293183123.stgit@warthog.procyon.org.uk> <158454391302.2863966.1884682840541676280.stgit@warthog.procyon.org.uk> <2003787.1595585999@warthog.procyon.org.uk> <865566fb800a014868a9a7e36a00a14430efb11e.camel@themaw.net> <2023286.1595590563@warthog.procyon.org.uk> <1283475.1596449889@warthog.procyon.org.uk> <1576646.1596455376@warthog.procyon.org.uk> To: Ian Kent Cc: dhowells@redhat.com, Miklos Szeredi , Linus Torvalds , Al Viro , Casey Schaufler , Stephen Smalley , Nicolas Dichtel , Christian Brauner , andres@anarazel.de, Jeff Layton , dray@redhat.com, Karel Zak , keyrings@vger.kernel.org, Linux API , linux-fsdevel@vger.kernel.org, LSM , linux-kernel@vger.kernel.org Subject: Re: [PATCH 13/17] watch_queue: Implement mount topology and attribute change notifications [ver #5] MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <1692825.1596457912.1@warthog.procyon.org.uk> Date: Mon, 03 Aug 2020 13:31:52 +0100 Message-ID: <1692826.1596457912@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ian Kent wrote: > > I'm changing it so that the fields are 64-bit, but initialised with the > > existing mount ID in the notifications set. The fsinfo set changes that > > to a unique ID. I'm tempted to make the unique IDs start at UINT_MAX+1 to > > disambiguate them. > > Mmm ... so what would I use as a mount id that's not used, like NULL > for strings? Zero is skipped, so you could use that. > I'm using -1 now but changing this will mean I need something > different. It's 64-bits, so you're not likely to see it reach -1, even if it does start at UINT_MAX+1. David