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=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 31F08C55186 for ; Thu, 23 Apr 2020 12:42:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0E1E32074F for ; Thu, 23 Apr 2020 12:42:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZmFiPMgD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726503AbgDWMmd (ORCPT ); Thu, 23 Apr 2020 08:42:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726435AbgDWMmb (ORCPT ); Thu, 23 Apr 2020 08:42:31 -0400 Received: from mail-ej1-x644.google.com (mail-ej1-x644.google.com [IPv6:2a00:1450:4864:20::644]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D2980C08E934 for ; Thu, 23 Apr 2020 05:42:30 -0700 (PDT) Received: by mail-ej1-x644.google.com with SMTP id n4so4546795ejs.11 for ; Thu, 23 Apr 2020 05:42:30 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:reply-to:from:date:message-id :subject:to:cc; bh=g5p9WEphfgq+H9j9tMYZw2/p4kg02/MHyB68bf7KToU=; b=ZmFiPMgDKvaATkttUA/Tr6v7xoLShlbiNnX9HkmF0lCGtOlDrwTTRX07qAM1UaRKli td3v7SMJXLrZJ+l5/xDtM1JXlFNwqKHK4sCFZ5VyygvzfBhSKaqkeXI4LWg85aMfYXzL F9pwZmVqYzlreVqaOtLYLtqbIF8StlLSt9clSYQFyg85Vns1IgEDAHtMVNYq6tJh17IC 8HifVlf1nTooBHj1YN553CdfjDmYIruOf4b/uAMfCJ07EYVebRdLozXtifTR0jHBQHCu Nj/W9fGSaZQQJAY5ucKvFrhegk+j4272cbss6MDH6GQDG8iPBSv58uXRbzDgx7IdlKG2 yDFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc; bh=g5p9WEphfgq+H9j9tMYZw2/p4kg02/MHyB68bf7KToU=; b=Orlr6JFcF0EClYZZv5sC1aNsxXXbT/zBg3wjS+Nzys66fFamHgUWQnIaizEFUIX//C o545fBhmDY99jTRYphfq61ummKUxk4AtxKRH6rsewwBo7qy+cY27tmtUTsSkcObLZoak xMeFwuZAn0yF/R9xMvGRoNZDi6Q69EPwO8shh+pnLv0IYAle1lVgrAmT4OSjAPKQU2oe HoMi8XJexiWm5r13fuPiyGvZS0+z4a8qBIABQAJltJeEpo45hVLvXoTfTb21PWpYa03n OpsZWl+7zpxexR2jn9eQnen+1yFn2MfNPATVAR7d+XahFcjZtBrB7rQ4oHLFtmN/suWg p8sA== X-Gm-Message-State: AGi0Pubs2l9KDqyZdSy0kYcD9+ErgMtGAQdPGonLQLVXjqE6PdtTzVcW Rv9qAIobosL6VNVu3dFn+cfAtVl5Mq+3LtZDH1U= X-Google-Smtp-Source: APiQypJCqiAlT8j7canXNzBjZOOMhm+SQ+7kGjJApkH91gGCHbvIPnQj48OPnWexyRL1PeR3ZbpfnbJhWG0tVEuDm4E= X-Received: by 2002:a17:906:54cd:: with SMTP id c13mr2279431ejp.307.1587645749350; Thu, 23 Apr 2020 05:42:29 -0700 (PDT) MIME-Version: 1.0 References: <20200423112352.GM3737@quack2.suse.cz> In-Reply-To: Reply-To: mtk.manpages@gmail.com From: "Michael Kerrisk (man-pages)" Date: Thu, 23 Apr 2020 14:42:18 +0200 Message-ID: Subject: Re: Kernel bugzilla 198569: fanotify_mark() and FAN_Q_OVERFLOW To: Amir Goldstein Cc: Jan Kara , Heinrich Schuchardt , linux-man , alexandermv@gmail.com, Matthew Bobrowski Content-Type: text/plain; charset="UTF-8" Sender: linux-man-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-man@vger.kernel.org Hello Amir, Jan, On Thu, 23 Apr 2020 at 14:19, Amir Goldstein wrote: > > On Thu, Apr 23, 2020 at 2:23 PM Jan Kara wrote: > > > > Hi Michael! > > > > On Thu 23-04-20 12:36:26, Michael Kerrisk (man-pages) wrote: > > > Would you be able to take a look at > > > https://bugzilla.kernel.org/show_bug.cgi?id=198569 > > > > > > It relates to some text you added to the fanotify_mark(2) manual page: > > > > > > FAN_Q_OVERFLOW > > > Create an event when an overflow of the event queue occurs. > > > The size of the event queue is limited to 16384 entries if > > > FAN_UNLIMITED_QUEUE is not set in fanotify_init(2). > > > > > > This was in the following commit > > > > > > [[ > > > commit 5d730f864a6603b090cd1078668cede05d02b8c4 > > > Author: Heinrich Schuchardt > > > Date: Tue Nov 8 23:13:38 2016 +0100 > > > > > > fanotify_mark.2: Mention FAN_Q_OVERFLOW > > > > > > To receive overflow events it is necessary to set this bit > > > in fanotify_mark(). > > > ]] > > > > > > As far as I can see, FAN_Q_OVERFLOW (test program, reading the kernel > > > source) is only an output flag. But on the other hand, I know you are > > > generally careful, so I wonder if something changed (though, at a > > > quick glance, I could not see evidence that it has). > > > > Yeah, the manpage is wrong AFAICT. FAN_Q_OVERFLOW is not accepted in the > > input mask. It is only output event flag. > > > > Right. > > Note that fanotify.7 documents FAN_Q_OVERFLOW as part of event output mask > so perhaps the FAN_Q_OVERFLOW entry for fanotify_mark.2 input mask should > just be removed? Yes, I'll just remove that piece from fanotify_mark.2. > > Similarly, the input only flag FAN_EVENT_ON_CHILD is documented in > fanotify_mark.2, but not in fanotify.7. > > FAN_ONDIR has been input only until v5.1 and since then it can also be > in output mask for group with FAN_REPORT_FID. > This is documented in fanotify_mark.2, but not in fanotify.7. I'm overlooking something: where is this detail documented in fanotify_mark.2? (I mean, I see mention of FAN_ONDIR, but no mention of a change in v5.1.) And would you be willing to write a small patch for fanotify.7 :-) ? Thanks, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/