Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751406AbaALMrZ (ORCPT ); Sun, 12 Jan 2014 07:47:25 -0500 Received: from mail-ee0-f52.google.com ([74.125.83.52]:63321 "EHLO mail-ee0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751224AbaALMrX (ORCPT ); Sun, 12 Jan 2014 07:47:23 -0500 Message-ID: <52D28ED8.6020102@dev.mellanox.co.il> Date: Sun, 12 Jan 2014 14:47:20 +0200 From: Sagi Grimberg User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: "Martin K. Petersen" CC: Sagi Grimberg , "Nicholas A. Bellinger" , target-devel , linux-scsi , linux-kernel , Christoph Hellwig , Hannes Reinecke , Or Gerlitz , Nicholas Bellinger , Oren Duer Subject: Re: [PATCH 07/14] target/sbc: Add P_TYPE + PROT_EN bits to READ_CAPACITY_16 References: <1389212157-14540-1-git-send-email-nab@daterainc.com> <1389212157-14540-8-git-send-email-nab@daterainc.com> <52CE78EB.60108@mellanox.com> <52D286D9.5050500@dev.mellanox.co.il> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/12/2014 2:33 PM, Martin K. Petersen wrote: >>>>>> "Sagi" == Sagi Grimberg writes: >>> I don't know of any non-disk devices that actually implement FORMAT >>> UNIT. Usually such configuration is done using the array management >>> interface. > Sagi> So this takes me to a corner I still don't understand, if a LUN is > Sagi> pre-formatted as T10-protected, what happens to unwritten blocks > Sagi> read? I mean, SCSI login executes some reads from sevel LBAs > Sagi> which will probably fail as blocks are unwritten. > > Per SBC, PI must be initialized to 0xffffffffffffffff. Since an app tag > value of 0xffff is an escape, this will prevent both target and > initiator from performing PI-verification when that block is read. OK, so this is an implicit escape (which will become explicit in DIX1.1?). So I will open that in DIF RDMA verbs. > If a block is subsequently written and no PI is sent from the host > (WRPROTECT=0), the target must generate valid PI for each block. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/