From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: [PATCH] Convert scsi_scan to use generic async mechanism Date: Sat, 23 May 2009 12:07:05 -0500 Message-ID: <1243098425.3630.26.camel@localhost.localdomain> References: <20090428193557.GC21648@parisc-linux.org> <1243095703.3630.24.camel@localhost.localdomain> <20090523095108.6ccccd08@infradead.org> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from bedivere.hansenpartnership.com ([66.63.167.143]:34178 "EHLO bedivere.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752181AbZEWRHE (ORCPT ); Sat, 23 May 2009 13:07:04 -0400 In-Reply-To: <20090523095108.6ccccd08@infradead.org> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Arjan van de Ven Cc: Matthew Wilcox , linux-scsi@vger.kernel.org, Brian King On Sat, 2009-05-23 at 09:51 -0700, Arjan van de Ven wrote: > On Sat, 23 May 2009 11:21:43 -0500 > > The reason scsi_add_device() is failing seems to be that > > async_synchronize_full_domain() is a bit fragile in that it only > > expects to be called once. Call it again, like we do, to make sure > > there aren't any outstanding scans and it hangs on the wait event. > > it's supposed to be ok to call as many times as you want. > What is NOT allowed is calling it from async work itself, due to the > obvious deadlock. The call trace doesn't seem to show we're nested ... although I suppose we could eventually be if someone decided to do async PCI scanning. Any other thoughts as to why this would be hanging? James