From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: Re: [PATCHv7 0/3][Resend] Display EVPD pages in sysfs Date: Wed, 05 Mar 2014 09:23:37 +0100 Message-ID: <5316DF09.4070704@acm.org> References: <1392287281-75002-1-git-send-email-hare@suse.de> <5312F1A1.4070605@acm.org> <5316D99D.3060005@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from smtp03.stone-is.org ([87.238.162.6]:38125 "EHLO smtpgw.stone-is.be" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751920AbaCEIXl (ORCPT ); Wed, 5 Mar 2014 03:23:41 -0500 In-Reply-To: <5316D99D.3060005@suse.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Hannes Reinecke , James Bottomley Cc: linux-scsi@vger.kernel.org, Christoph Hellwig On 03/05/14 09:00, Hannes Reinecke wrote: > On 03/02/2014 09:53 AM, Bart Van Assche wrote: >> A general comment about this patch series: I think the cached copies of >> these pages should be refreshed at least after an INQUIRY DATA HAS >> CHANGED unit attention code has been received. Some SCSI target >> implementations allow to change this data after a LUN has been created. > > Yes, eventually. But this needs to be handled in a general context, > as (potentially) even the inquiry string itself has been invalidated > after receiving such an event. > So we should be doing a rescan of the scsi device upon receiving > such an event. But this is a general problem, not one particular to > this patchset. Sorry but since the ALUA patch series is based on this patch series I'm afraid that the ALUA patch series introduces a regression that seems unacceptable to me. SCSI target implementations like LIO allow to remove and re-add a LUN after initial discovery of a SCSI host. My concern here is that the caching introduced by this patch series and which is used in the ALUA patch series will cause INQUIRY data not to be updated after it has been changed at the target side. Today the scsi_dh_alua handler processes such INQUIRY data changes fine. Does this make sense to you ? Thanks, Bart.