Received: by 2002:ac0:a581:0:0:0:0:0 with SMTP id m1-v6csp5306453imm; Tue, 26 Jun 2018 09:04:30 -0700 (PDT) X-Google-Smtp-Source: ADUXVKKlKl+CjwBG+n0ur2Mmb6xKEzih0NeD94FVJvUhi9KZ6N+FQZ2q6L1YZy2DrJ4N4X37vWV2 X-Received: by 2002:a65:4809:: with SMTP id h9-v6mr1959334pgs.258.1530029070535; Tue, 26 Jun 2018 09:04:30 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1530029070; cv=none; d=google.com; s=arc-20160816; b=VnHwaH2sb4YZctu4Nfqxg+jCOBOa4djWQ6SvIHPiLFMtJ71glbZHdJw+wQshYSposl XBEmlvFuQtwe/2JG2moEZuM4HFIt7rj9L6pGixDwAZTszqbCMdxmi/nEZJt11QgxLCHI GlyNpPjNbvIPYXqeaQapuIjThz2Hv6LAHgS/jOfTe824nIxUSyefASLWGlisgJQ/6c0l 8mg6ZfeeVZrPrhu7oYfNzudfiHClNiGd/F95khJxz5ME4Ia+LjNBqG0qZcTiUo4zSecI i9ms3Wwj1Eyu3nPYo8OG177Gv/Sqn0C+1tlOaR7RLiDoBwpXBtzM8oSIpgauFtg0660t EYHw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding :content-language:in-reply-to:mime-version:user-agent:date :message-id:from:references:cc:to:subject:arc-authentication-results; bh=zzcB2Rum4gMPZOZKqtA8j9NU4QO7LWS94u23ghO6SCs=; b=gBxxk03GfMbz+yyhnn+6PWuGt7u5zpWjGdlrp2GwFMPgndINVWHekUPBbyC5mszjyK hYfKjG5+3GY3XIr2BEbbKzti35VyfFANtRDhBZAQXlDRSEa/v60LQ1EJYFTIaNlMfESt CYI24TXe4pvcEhO5LNjNxYx7GDYJ8Gm7SthCDZtnYkIGhviJUWNTO5iFccrrtb0OHom/ A0913RFaReX8J4tAjwjmKxohmfrvbYtl58v6KK3W/Csoj/rXMO8FmXg0n1WCjsLmVvLM nycTI6JpcazIRwiy/eSpDhbNXP2v41FUJpe61FRZDEyi/4KB1Hhw8vSEXCfyqjaXH7OU Pipw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id o2-v6si24098pgn.600.2018.06.26.09.04.15; Tue, 26 Jun 2018 09:04:30 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965823AbeFZOfI (ORCPT + 99 others); Tue, 26 Jun 2018 10:35:08 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:21269 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965304AbeFZOfH (ORCPT ); Tue, 26 Jun 2018 10:35:07 -0400 Received: from fsav302.sakura.ne.jp (fsav302.sakura.ne.jp [153.120.85.133]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id w5QEZ0Cd024570; Tue, 26 Jun 2018 23:35:00 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav302.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav302.sakura.ne.jp); Tue, 26 Jun 2018 23:35:00 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav302.sakura.ne.jp) Received: from [192.168.1.8] (softbank126074194044.bbtec.net [126.74.194.44]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id w5QEYtFB024497 (version=TLSv1.2 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 26 Jun 2018 23:35:00 +0900 (JST) (envelope-from penguin-kernel@i-love.sakura.ne.jp) Subject: Re: [PATCH v3] block/loop: Serialize ioctl operations. To: Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot , syzbot References: <1527297408-4428-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <748bce03-afda-4ed2-13b3-1fcd01d57770@kernel.dk> From: Tetsuo Handa Message-ID: <9a9209af-c841-6034-4b4f-46d93aa0c037@i-love.sakura.ne.jp> Date: Tue, 26 Jun 2018 23:34:52 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.8.0 MIME-Version: 1.0 In-Reply-To: <748bce03-afda-4ed2-13b3-1fcd01d57770@kernel.dk> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Did you get any idea? On 2018/06/05 3:13, Jens Axboe wrote: > On 6/4/18 5:19 AM, Tetsuo Handa wrote: >> This problem was already ignored for 8 months. Unless we boost priority, >> this problem will be ignored for years. Jens, can we test this patch? > > Sorry, it's just that I _really_ hate this patch. We're making up > a weird locking primitive that tracks the process, with a weird > unlock helper that only unlocks if it's the process that is > holding the mutex. > > I'll try and think about this a bit, it would be nice if we had > a better alternative than the above. >