From patchwork Fri Dec 8 10:14:08 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 10102223 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 36F59602A0 for ; Fri, 8 Dec 2017 10:14:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 26A6528AE6 for ; Fri, 8 Dec 2017 10:14:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1B8C228B9D; Fri, 8 Dec 2017 10:14:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 87BCE28AE6 for ; Fri, 8 Dec 2017 10:14:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752845AbdLHKOM (ORCPT ); Fri, 8 Dec 2017 05:14:12 -0500 Received: from mx2.suse.de ([195.135.220.15]:47485 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751321AbdLHKOL (ORCPT ); Fri, 8 Dec 2017 05:14:11 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 1B059ACA5; Fri, 8 Dec 2017 10:14:10 +0000 (UTC) From: Hannes Reinecke To: "Martin K. Petersen" Cc: Christoph Hellwig , James Bottomley , linux-scsi@vger.kernel.org, Hannes Reinecke Subject: [PATCH] scsi_dh_alua: skip RTPG for devices only supporting active/optimized Date: Fri, 8 Dec 2017 11:14:08 +0100 Message-Id: <1512728048-84729-1-git-send-email-hare@suse.de> X-Mailer: git-send-email 1.8.5.6 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Hannes Reinecke For hardware only supporting active/optimized there's no point in ever re-issuing RTPG as the only new state we can possibly read is active/optimized. This avoid spurious errors during path failover on such arrays. Signed-off-by: Hannes Reinecke --- drivers/scsi/device_handler/scsi_dh_alua.c | 35 ++++++++++++++++++++++-------- 1 file changed, 26 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index fd22dc6..b09c12b 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -40,6 +40,7 @@ #define TPGS_SUPPORT_LBA_DEPENDENT 0x10 #define TPGS_SUPPORT_OFFLINE 0x40 #define TPGS_SUPPORT_TRANSITION 0x80 +#define TPGS_SUPPORT_ALL 0xdf #define RTPG_FMT_MASK 0x70 #define RTPG_FMT_EXT_HDR 0x10 @@ -81,6 +82,7 @@ struct alua_port_group { int tpgs; int state; int pref; + int valid_states; unsigned flags; /* used for optimizing STPG */ unsigned char transition_tmo; unsigned long expiry; @@ -243,6 +245,7 @@ static struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev, pg->group_id = group_id; pg->tpgs = tpgs; pg->state = SCSI_ACCESS_STATE_OPTIMAL; + pg->valid_states = TPGS_SUPPORT_ALL; if (optimize_stpg) pg->flags |= ALUA_OPTIMIZE_STPG; kref_init(&pg->kref); @@ -516,7 +519,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) { struct scsi_sense_hdr sense_hdr; struct alua_port_group *tmp_pg; - int len, k, off, valid_states = 0, bufflen = ALUA_RTPG_SIZE; + int len, k, off, bufflen = ALUA_RTPG_SIZE; unsigned char *desc, *buff; unsigned err, retval; unsigned int tpg_desc_tbl_off; @@ -541,6 +544,20 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) retval = submit_rtpg(sdev, buff, bufflen, &sense_hdr, pg->flags); if (retval) { + /* + * If the target only supports active/optimized there's + * not much we can do; it's not that we can switch paths + * or somesuch. + * So ignore any errors to avoid spurious failures during + * path failover. + */ + if ((pg->valid_states & ~TPGS_SUPPORT_OPTIMIZED) == 0) { + sdev_printk(KERN_INFO, sdev, + "%s: ignoring rtpg result %d\n", + ALUA_DH_NAME, retval); + kfree(buff); + return SCSI_DH_OK; + } if (!scsi_sense_valid(&sense_hdr)) { sdev_printk(KERN_INFO, sdev, "%s: rtpg failed, result %d\n", @@ -652,7 +669,7 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) rcu_read_unlock(); } if (tmp_pg == pg) - valid_states = desc[1]; + tmp_pg->valid_states = desc[1]; spin_unlock_irqrestore(&tmp_pg->lock, flags); } kref_put(&tmp_pg->kref, release_port_group); @@ -665,13 +682,13 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) "%s: port group %02x state %c %s supports %c%c%c%c%c%c%c\n", ALUA_DH_NAME, pg->group_id, print_alua_state(pg->state), pg->pref ? "preferred" : "non-preferred", - valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', - valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', - valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', - valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', - valid_states&TPGS_SUPPORT_STANDBY?'S':'s', - valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', - valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); + pg->valid_states&TPGS_SUPPORT_TRANSITION?'T':'t', + pg->valid_states&TPGS_SUPPORT_OFFLINE?'O':'o', + pg->valid_states&TPGS_SUPPORT_LBA_DEPENDENT?'L':'l', + pg->valid_states&TPGS_SUPPORT_UNAVAILABLE?'U':'u', + pg->valid_states&TPGS_SUPPORT_STANDBY?'S':'s', + pg->valid_states&TPGS_SUPPORT_NONOPTIMIZED?'N':'n', + pg->valid_states&TPGS_SUPPORT_OPTIMIZED?'A':'a'); switch (pg->state) { case SCSI_ACCESS_STATE_TRANSITIONING: