From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: Bug in SCSI async probing Date: Tue, 26 May 2009 10:34:23 -0500 Message-ID: <1243352063.2815.34.camel@localhost.localdomain> References: Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from bedivere.hansenpartnership.com ([66.63.167.143]:41315 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753683AbZEZPeX (ORCPT ); Tue, 26 May 2009 11:34:23 -0400 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Alan Stern Cc: Arjan van de Ven , SCSI development list , Kernel development list On Tue, 2009-05-26 at 11:22 -0400, Alan Stern wrote: > James & Arjan: > > Am I missing something here? It looks like > > fastboot: make scsi probes asynchronous > > has introduced a bug in the sd probing code. AFAICT, there is now > nothing to prevent do_scan_async() from returning before > sd_probe_async() has run. True, but this isn't really a problem. > Doesn't this mean that there's nothing to prevent sd_remove() from > being called and trying to unregister the disk _before_ > sd_probe_async() has managed to register it? Yes, we've been discussing this ... most of the removal functions now need async_synchronize calls to mitigate this type of race. James