From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from johann.somewhere (chello080108047253.34.11.vie.surfer.at [80.108.47.253]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by mail.linbit.com (LINBIT Mail Daemon) with ESMTP id 1F1B22E08BE3 for ; Sun, 13 Jan 2008 04:15:00 +0100 (CET) Date: Sun, 13 Jan 2008 04:14:59 +0100 From: Lars Ellenberg To: drbd-dev@lists.linbit.com Subject: Re: [Drbd-dev] Crash in lru_cache.c Message-ID: <20080113031459.GA30312@debian-etc-mailname> References: <342BAC0A5467384983B586A6B0B3767107C5B0B7@EXNA.corp.stratus.com> <342BAC0A5467384983B586A6B0B3767107C5B0C0@EXNA.corp.stratus.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <342BAC0A5467384983B586A6B0B3767107C5B0C0@EXNA.corp.stratus.com> List-Id: Coordination of development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sat, Jan 12, 2008 at 06:37:47PM -0500, Graham, Simon wrote: > > sure I can have requests there, but they are not yet completed to > upper > > layers. if they are, their correponding barrier will have been send > > out > > already. > > > > for attach, we would then do > > block new incomming request > > wait for ap count to reach zero > > [in current code, send out a barrier now; > > with the idea outline above, there is no need for that] > > wait for the lates barrier ack > > (tl now empty) > > attach > > unblock > > > > am I still missing something? > > I think that works. > > What's the appropriate mechanism for blocking new requests? There are > existing mechanisms based on locking the AL cache entry, but since there > is no AL at this time, we cant use that... there is an other one, examining the drbd state, right as the first statement in drbd_make_request_common inc_ap_bio __inc_ap_bio_cond :-) I have to think about whether we need yet an other itermediate state. probably blocking anything for Diskless < state < Inconsistent would be enough. -- : Lars Ellenberg Tel +43-1-8178292-55 : : LINBIT Information Technologies GmbH Fax +43-1-8178292-82 : : Vivenotgasse 48, A-1120 Vienna/Europe http://www.linbit.com :