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=-9.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 B8CF7C433E0 for ; Mon, 8 Feb 2021 07:40:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 77C4564E76 for ; Mon, 8 Feb 2021 07:40:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230103AbhBHHki (ORCPT ); Mon, 8 Feb 2021 02:40:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229621AbhBHHke (ORCPT ); Mon, 8 Feb 2021 02:40:34 -0500 Received: from mail-lj1-x236.google.com (mail-lj1-x236.google.com [IPv6:2a00:1450:4864:20::236]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4194DC06174A; Sun, 7 Feb 2021 23:39:53 -0800 (PST) Received: by mail-lj1-x236.google.com with SMTP id c18so15742466ljd.9; Sun, 07 Feb 2021 23:39:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=3qO9XtGjtAL1hXm5+HTnDd4FC41lJytDGSMy8XTKh0Y=; b=SSzgvzvhKMHtU5nb6Uvar2B0cFRNGCAJDt/7VgieRpNZPcSNm5GGig1mk0SSqzTwFj zJDkYA9ndFHjAJRcbHa8BQGsi6Fe0cWyufMI6X7IrCx8hcDAISa8ezTItBL0b3EmqyNJ n07+NgyhAW/o2QS50he7tNgpbyWLSojPttwgPgryE/1EypL4Q1HqSbqOX1UVUh3ldn2W 5RPASflWE8bki5+i6LZcOt7V2c1E9wxxQPSNq3oaDJJjLJBk3Nh9SCi/HQqmDdRB8zyc JxkYHlUjnSojUZ+OZkKJujlHLO98oH8UClFBmkn5arBZfE0VNrax0wnaou9xuKc4VfHE 6/qg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=3qO9XtGjtAL1hXm5+HTnDd4FC41lJytDGSMy8XTKh0Y=; b=XJlrWoVCiQlBRFm/mOtMN2/XZGAm9fCGhkWpYG2BFDzeUs2HNwBXKeeXAlp9wo3157 RjJ0E63llz1CWXjbErvw49ZcMtNDnntp3qO7VP1QcvFoKeYvYyckeKdvI1BGHT7AHfNe np3YlaNMaKB7risVZk0SUB2ciexm3Ab0CZc+9bwCGIA/XHnIrKFInQbuPaEcdD0mHtJN GxFOf/cRiTX+dgjMDUsUh6K89dmx3OIqQLdsMB/b7XlbYWCtTA6aado6R/wbwMqGetp6 6O7Vu6PRdB1MEFYYD7GzXZovQWylCbpG3fG8YoEaeLdXT33j4WZXj/vjuiqsT7hYhzsy LmnQ== X-Gm-Message-State: AOAM532Zn85/1d2L2GAwLFvz+8/r5U4nzOu41o/VZz3haw4XLRB6TMcb /xZXvHkVgVy4bz7+pY7js40= X-Google-Smtp-Source: ABdhPJxqpCLTaXiL+9+ZXD3CJD6SAwIS5h7wnlRva1TXgfXvHkKWU59aqVSBjTillqyxRnyEbSxz1Q== X-Received: by 2002:a2e:bc1a:: with SMTP id b26mr10238231ljf.294.1612769991678; Sun, 07 Feb 2021 23:39:51 -0800 (PST) Received: from grain.localdomain ([5.18.103.226]) by smtp.gmail.com with ESMTPSA id r136sm1971361lff.247.2021.02.07.23.39.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 07 Feb 2021 23:39:50 -0800 (PST) Received: by grain.localdomain (Postfix, from userid 1000) id 94ED2560163; Mon, 8 Feb 2021 10:39:49 +0300 (MSK) Date: Mon, 8 Feb 2021 10:39:49 +0300 From: Cyrill Gorcunov To: Pavel Tikhomirov Cc: Jeff Layton , Jeff Layton , "J. Bruce Fields" , Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Andrei Vagin Subject: Re: [PATCH] fcntl: make F_GETOWN(EX) return 0 on dead owner task Message-ID: <20210208073949.GL2172@grain> References: <20210203124156.425775-1-ptikhomirov@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210203124156.425775-1-ptikhomirov@virtuozzo.com> User-Agent: Mutt/1.14.6 (2020-07-11) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Feb 03, 2021 at 03:41:56PM +0300, Pavel Tikhomirov wrote: > Currently there is no way to differentiate the file with alive owner > from the file with dead owner but pid of the owner reused. That's why > CRIU can't actually know if it needs to restore file owner or not, > because if it restores owner but actual owner was dead, this can > introduce unexpected signals to the "false"-owner (which reused the > pid). > > Let's change the api, so that F_GETOWN(EX) returns 0 in case actual > owner is dead already. > > Cc: Jeff Layton > Cc: "J. Bruce Fields" > Cc: Alexander Viro > Cc: linux-fsdevel@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Cc: Cyrill Gorcunov > Cc: Andrei Vagin > Signed-off-by: Pavel Tikhomirov I can't imagine a scenario where we could break some backward compatibility with this change, so Reviewed-by: Cyrill Gorcunov