From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <SRS0=Yun1=YR=vger.kernel.org=linux-kernel-owner@kernel.org>
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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,
	MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 82055CA9EAF
	for <linux-kernel@archiver.kernel.org>; Thu, 24 Oct 2019 13:19:11 +0000 (UTC)
Received: from vger.kernel.org (vger.kernel.org [209.132.180.67])
	by mail.kernel.org (Postfix) with ESMTP id 5C9E02084C
	for <linux-kernel@archiver.kernel.org>; Thu, 24 Oct 2019 13:19:11 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S2502489AbfJXNTK (ORCPT
        <rfc822;linux-kernel@archiver.kernel.org>);
        Thu, 24 Oct 2019 09:19:10 -0400
Received: from mx2.suse.de ([195.135.220.15]:34614 "EHLO mx1.suse.de"
        rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP
        id S1730061AbfJXNTK (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
        Thu, 24 Oct 2019 09:19:10 -0400
X-Virus-Scanned: by amavisd-new at test-mx.suse.de
Received: from relay2.suse.de (unknown [195.135.220.254])
        by mx1.suse.de (Postfix) with ESMTP id A9A3DB7FD;
        Thu, 24 Oct 2019 13:19:07 +0000 (UTC)
Date:   Thu, 24 Oct 2019 15:19:05 +0200
From:   Michal =?iso-8859-1?Q?Such=E1nek?= <msuchanek@suse.de>
To:     Matthew Wilcox <willy@infradead.org>
Cc:     Christoph Hellwig <hch@infradead.org>, linux-scsi@vger.kernel.org,
        Jonathan Corbet <corbet@lwn.net>, Jens Axboe <axboe@kernel.dk>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        "Martin K. Petersen" <martin.petersen@oracle.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Mauro Carvalho Chehab <mchehab+samsung@kernel.org>,
        Eric Biggers <ebiggers@google.com>,
        "J. Bruce Fields" <bfields@redhat.com>,
        Benjamin Coddington <bcodding@redhat.com>,
        Hannes Reinecke <hare@suse.com>,
        Omar Sandoval <osandov@fb.com>, Ming Lei <ming.lei@redhat.com>,
        Damien Le Moal <damien.lemoal@wdc.com>,
        Bart Van Assche <bvanassche@acm.org>,
        Tejun Heo <tj@kernel.org>, linux-doc@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH v2 6/8] bdev: add open_finish.
Message-ID: <20191024131905.GM938@kitsune.suse.cz>
References: <cover.1571834862.git.msuchanek@suse.de>
 <ea2652294651cbc8549736728c650d16d2fe1808.1571834862.git.msuchanek@suse.de>
 <20191024022232.GB11485@infradead.org>
 <20191024085514.GI938@kitsune.suse.cz>
 <20191024131254.GE2963@bombadil.infradead.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20191024131254.GE2963@bombadil.infradead.org>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Thu, Oct 24, 2019 at 06:12:54AM -0700, Matthew Wilcox wrote:
> On Thu, Oct 24, 2019 at 10:55:14AM +0200, Michal Suchánek wrote:
> > On Wed, Oct 23, 2019 at 07:22:32PM -0700, Christoph Hellwig wrote:
> > > On Wed, Oct 23, 2019 at 02:52:45PM +0200, Michal Suchanek wrote:
> > > > Opening a block device may require a long operation such as waiting for
> > > > the cdrom tray to close. Performing this operation with locks held locks
> > > > out other attempts to open the device. These processes waiting to open
> > > > the device are not killable.
> 
> You can use mutex_lock_killable() to fix that.
> 

That solves only half of the problem.

It still does not give access to the device to processes that open with
O_NONBLOCK.

Thanks

Michal