From patchwork Tue Dec 8 07:37:35 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 7795251 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 2FA5CBEEE5 for ; Tue, 8 Dec 2015 07:37:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2A61F2052C for ; Tue, 8 Dec 2015 07:37:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 28D1220527 for ; Tue, 8 Dec 2015 07:37:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933226AbbLHHhw (ORCPT ); Tue, 8 Dec 2015 02:37:52 -0500 Received: from mx2.suse.de ([195.135.220.15]:46088 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933204AbbLHHhr (ORCPT ); Tue, 8 Dec 2015 02:37:47 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 39759ACCD; Tue, 8 Dec 2015 07:37:42 +0000 (UTC) From: Hannes Reinecke To: "Martin K. Petersen" Cc: James Bottomley , Christoph Hellwig , Ewan Milne , Bart van Assche , linux-scsi@vger.kernel.org, Hannes Reinecke Subject: [PATCH 15/20] scsi_dh_alua: Send TEST UNIT READY to poll for transitioning Date: Tue, 8 Dec 2015 08:37:35 +0100 Message-Id: <1449560260-53407-16-git-send-email-hare@suse.de> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: <1449560260-53407-1-git-send-email-hare@suse.de> References: <1449560260-53407-1-git-send-email-hare@suse.de> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Sending a 'REPORT TARGET PORT GROUP' command is a costly operation, as the array has to gather information about all ports. So instead of using RTPG to poll for a status update when a port is in transitioning we should be sending a TEST UNIT READY, and wait for the sense code to report success. Signed-off-by: Hannes Reinecke Reviewed-by: Ewan Milne Reviewed-by: Christoph Hellwig --- drivers/scsi/device_handler/scsi_dh_alua.c | 37 ++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index 6ddbb88..6014750 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -489,6 +489,30 @@ static int alua_check_sense(struct scsi_device *sdev, } /* + * alua_tur - Send a TEST UNIT READY + * @sdev: device to which the TEST UNIT READY command should be send + * + * Send a TEST UNIT READY to @sdev to figure out the device state + * Returns SCSI_DH_RETRY if the sense code is NOT READY/ALUA TRANSITIONING, + * SCSI_DH_OK if no error occurred, and SCSI_DH_IO otherwise. + */ +static int alua_tur(struct scsi_device *sdev) +{ + struct scsi_sense_hdr sense_hdr; + int retval; + + retval = scsi_test_unit_ready(sdev, ALUA_FAILOVER_TIMEOUT * HZ, + ALUA_FAILOVER_RETRIES, &sense_hdr); + if (sense_hdr.sense_key == NOT_READY && + sense_hdr.asc == 0x04 && sense_hdr.ascq == 0x0a) + return SCSI_DH_RETRY; + else if (retval) + return SCSI_DH_IO; + else + return SCSI_DH_OK; +} + +/* * alua_rtpg - Evaluate REPORT TARGET GROUP STATES * @sdev: the device to be evaluated. * @@ -752,7 +776,20 @@ static void alua_rtpg_work(struct work_struct *work) } pg->flags |= ALUA_PG_RUNNING; if (pg->flags & ALUA_PG_RUN_RTPG) { + int state = pg->state; + spin_unlock_irqrestore(&pg->lock, flags); + if (state == TPGS_STATE_TRANSITIONING) { + if (alua_tur(sdev) == SCSI_DH_RETRY) { + spin_lock_irqsave(&pg->lock, flags); + pg->flags &= ~ALUA_PG_RUNNING; + spin_unlock_irqrestore(&pg->lock, flags); + queue_delayed_work(kaluad_wq, &pg->rtpg_work, + pg->interval * HZ); + return; + } + /* Send RTPG on failure or if TUR indicates SUCCESS */ + } err = alua_rtpg(sdev, pg); spin_lock_irqsave(&pg->lock, flags); if (err == SCSI_DH_RETRY) {