From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] vfs: try to unblock evpoll if mounted filesystem is RDONLY Date: Thu, 25 Jul 2013 13:30:57 -0400 Message-ID: <20130725173057.GH26107@mtj.dyndns.org> References: <1373248974-3272-1-git-send-email-jason77.wang@gmail.com> <20130723154555.GC18458@mtj.dyndns.org> <20130723214844.GA25333@quack.suse.cz> <51EFA7A8.4010401@canonical.com> <20130724183931.GB27307@quack.suse.cz> <51F09A50.4040805@canonical.com> <20130725100358.GC9388@quack.suse.cz> <20130725153335.GG26107@mtj.dyndns.org> <20130725172723.GA18011@quack.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Hui Wang , viro@zeniv.linux.org.uk, kay.sievers@vrfy.org, jaxboe@fusionio.com, linux-fsdevel@vger.kernel.org To: Jan Kara Return-path: Received: from mail-yh0-f47.google.com ([209.85.213.47]:37381 "EHLO mail-yh0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756533Ab3GYRbF (ORCPT ); Thu, 25 Jul 2013 13:31:05 -0400 Received: by mail-yh0-f47.google.com with SMTP id z20so646640yhz.20 for ; Thu, 25 Jul 2013 10:31:04 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20130725172723.GA18011@quack.suse.cz> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: Hello, Jan. On Thu, Jul 25, 2013 at 07:27:23PM +0200, Jan Kara wrote: > MS_RDONLY will fail even currently (tried that in practice, also see the > check in blkdev_get_by_path()). So such tool should handle that case even > currently. The only somewhat realistic case I'm aware of is if someone uses > UDF on e.g. USB stick, it is created so that Linux doesn't support writing > to it, and then some tool would be mounting it directly via syscall and would > not handle the read-only media case right. But I don't find this likely so > I think it would be worth trying out this approach before we try playing > tricks with dropping write access... Hmm? I see. Yeah, if it's highly unlikely to be noticeable, I think it's a neat approach. No objection from me. Thanks! -- tejun