From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: Re: Scsi Error handling query Date: Fri, 27 Mar 2015 17:02:16 +0100 Message-ID: <55157F08.3070707@suse.de> References: <5d00e10b067fd4d0fb82ecdec18dd325@mail.gmail.com> <55142C6D.1060205@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from cantor2.suse.de ([195.135.220.15]:42151 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932504AbbC0QCU (ORCPT ); Fri, 27 Mar 2015 12:02:20 -0400 In-Reply-To: Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Kashyap Desai , linux-scsi@vger.kernel.org On 03/26/2015 07:43 PM, Kashyap Desai wrote: >> -----Original Message----- >> From: Hannes Reinecke [mailto:hare@suse.de] >> Sent: Thursday, March 26, 2015 9:28 PM >> To: Kashyap Desai; linux-scsi@vger.kernel.org >> Subject: Re: Scsi Error handling query >> >> On 03/26/2015 02:38 PM, Kashyap Desai wrote: >>> Hi Hannes, >>> >>> I was going through one of the slide posted at below link. >>> >>> http://events.linuxfoundation.org/sites/events/files/slides/SCSI-EH= =2Epd >>> f >>> >>> Slide #59 has below data. I was trying to correlate with latest >>> upstream code, but do not understand few things. Does Linux handle >>> blocking I/O to the device and target before it actually start lega= cy EH >> recovery ? >> >> Yes. This is handled by 'scsi_eh_scmd_add()', which adds the command= to >> the >> internal 'eh_entry' list and starts recovery once all remaining >> outstanding >> commands are completed. >=20 > Thanks Hannes..! Scsi_eh_scmd_add() move shost state to recovery, so = it > means blocking further IO to the Host and not really a limited to > Device/Target for which command was timed out. Right ? > I understood that, new improvement of scsi error handling will allow = IOs to > the other Devices attached to the host except the IO belongs to speci= fic > target. >=20 > Also, one more thing to clarify... In presentation, term "task set ab= orts" > was used. Does this mean task set abort is handled as traversing comp= lete > list of timed out command and sending individual TASK ABORT ? >=20 No. The idea was to send 'task set aborts' as a single TMF. However, I'm not sure if I'll be going ahead with that one; once we've issued a 'transport reset the commands will be cone anyway. Cheers, Hannes --=20 Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N=C3=BCrnberg GF: F. Imend=C3=B6rffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG N=C3=BCrnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html