From: "Takashi Sato" Subject: Re: [PATCH 3/3] Add timeout feature Date: Fri, 26 Sep 2008 17:52:35 +0900 Message-ID: References: <20080908205337t-sato@mail.jp.nec.com> <20080908171119.GB22521@infradead.org> <48DBFD42.6030307@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit Cc: "Andrew Morton" , "Oleg Nesterov" , , , , , , , , To: "Ric Wheeler" , "Christoph Hellwig" Return-path: Received: from TYO201.gate.nec.co.jp ([202.32.8.193]:58944 "EHLO tyo201.gate.nec.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751714AbYIZIxo (ORCPT ); Fri, 26 Sep 2008 04:53:44 -0400 In-Reply-To: <48DBFD42.6030307@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi, Ric Wheeler wrote: > Christoph Hellwig wrote: >> On Mon, Sep 08, 2008 at 08:53:37PM +0900, Takashi Sato wrote: >> >>> The timeout feature is added to "freeze ioctl" to solve a deadlock >>> when the freezer accesses a frozen filesystem. And new ioctl >>> to reset the timeout period is added to extend the timeout period. >>> For example, the freezer resets the timeout period to 10 seconds every 5 >>> seconds. In this approach, even if the freezer causes a deadlock by >>> accessing the frozen filesystem, it will be solved by the timeout >>> in 10 seconds and the freezer will be able to recognize that >>> at the next reset of timeout period. >>> >> >> And as with all previous posting I still fundamentally disagree about >> the need of this functionality. We don't need a timeout for freezing. > > I agree with Christoph here, I think that the timeout is unneeded. I think that your concern is that the freezer cannot recognize the occurrence of a timeout and it continues the backup process and the backup data is corrupted finally. If the freezer can recognize it by the unfreeze ioctl's errono, will your concern be solved? If so, I will implement it. Cheers, Takashi