From patchwork Mon May 4 12:42:21 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 6325971 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 05141BEEE1 for ; Mon, 4 May 2015 12:43:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id EAC9720376 for ; Mon, 4 May 2015 12:43:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8EDFF2037C for ; Mon, 4 May 2015 12:43:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753027AbbEDMm5 (ORCPT ); Mon, 4 May 2015 08:42:57 -0400 Received: from cantor2.suse.de ([195.135.220.15]:47368 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753354AbbEDMmn (ORCPT ); Mon, 4 May 2015 08:42:43 -0400 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 B13FEAD6B; Mon, 4 May 2015 12:42:27 +0000 (UTC) From: Hannes Reinecke To: James Bottomley Cc: Christoph Hellwig , linux-scsi@vger.kernel.org, Hannes Reinecke Subject: [PATCH 15/17] scsi_dh_alua: Recheck state on unit attention Date: Mon, 4 May 2015 14:42:21 +0200 Message-Id: <1430743343-47174-16-git-send-email-hare@suse.de> X-Mailer: git-send-email 1.8.5.2 In-Reply-To: <1430743343-47174-1-git-send-email-hare@suse.de> References: <1430743343-47174-1-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=unavailable 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 When we receive a unit attention code of 'ALUA state changed' we should recheck the state, as it might be due to an implicit ALUA state transition. At the same time a workqueue item might already be queued, which should be started immediately to avoid any delays. Signed-off-by: Hannes Reinecke --- drivers/scsi/device_handler/scsi_dh_alua.c | 65 +++++++++++++++++------------- 1 file changed, 36 insertions(+), 29 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index 142c95b..cf83005 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -69,6 +69,7 @@ /* State machine flags */ #define ALUA_PG_RUN_RTPG 0x10 #define ALUA_PG_RUN_STPG 0x20 +#define ALUA_PG_RUNNING 0x40 static LIST_HEAD(port_group_list); @@ -119,7 +120,7 @@ struct alua_queue_data { static char print_alua_state(int); static int alua_check_sense(struct scsi_device *, struct scsi_sense_hdr *); static void alua_rtpg_work(struct work_struct *work); -static void alua_check(struct scsi_device *sdev); +static void alua_check(struct scsi_device *sdev, bool force); static int realloc_buffer(struct alua_port_group *pg, unsigned len) { @@ -487,7 +488,7 @@ static char print_alua_state(int state) } static int alua_check_sense(struct scsi_device *sdev, - struct scsi_sense_hdr *sense_hdr) + struct scsi_sense_hdr *sense_hdr) { switch (sense_hdr->sense_key) { case NOT_READY: @@ -496,36 +497,34 @@ static int alua_check_sense(struct scsi_device *sdev, * LUN Not Accessible - ALUA state transition * Kickoff worker to update internal state. */ - alua_check(sdev); - return ADD_TO_MLQUEUE; + alua_check(sdev, false); + return NEEDS_RETRY; } break; case UNIT_ATTENTION: - if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) - /* - * Power On, Reset, or Bus Device Reset, just retry. - */ - return ADD_TO_MLQUEUE; - if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x04) - /* - * Device internal reset - */ - return ADD_TO_MLQUEUE; - if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x01) + if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) { /* - * Mode parameter changed + * Power On, Reset, or Bus Device Reset. + * Might have obscured a state transition, + * so schedule a recheck. */ + alua_check(sdev, true); return ADD_TO_MLQUEUE; - if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) + } + if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x06) { /* * ALUA state changed */ + alua_check(sdev, true); return ADD_TO_MLQUEUE; - if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) + } + if (sense_hdr->asc == 0x2a && sense_hdr->ascq == 0x07) { /* * Implicit ALUA state transition failed */ + alua_check(sdev, true); return ADD_TO_MLQUEUE; + } break; } @@ -589,7 +588,6 @@ static int alua_rtpg(struct scsi_device *sdev, struct alua_port_group *pg) goto retry; } - err = alua_check_sense(sdev, &sense_hdr); if (sense_hdr.sense_key == UNIT_ATTENTION) err = ADD_TO_MLQUEUE; if (err == ADD_TO_MLQUEUE && @@ -744,7 +742,6 @@ static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg) /* Retry RTPG */ return err; } - err = alua_check_sense(sdev, &sense_hdr); sdev_printk(KERN_INFO, sdev, "%s: stpg failed\n", ALUA_DH_NAME); scsi_print_sense_hdr(sdev, ALUA_DH_NAME, &sense_hdr); @@ -771,15 +768,18 @@ static void alua_rtpg_work(struct work_struct *work) spin_unlock_irqrestore(&pg->rtpg_lock, flags); return; } + pg->flags |= ALUA_PG_RUNNING; if (pg->flags & ALUA_PG_RUN_RTPG) { spin_unlock_irqrestore(&pg->rtpg_lock, flags); err = alua_rtpg(sdev, pg); + spin_lock_irqsave(&pg->rtpg_lock, flags); if (err == SCSI_DH_RETRY) { + pg->flags &= ~ALUA_PG_RUNNING; + spin_unlock_irqrestore(&pg->rtpg_lock, flags); queue_delayed_work(scsidh_aluad, &pg->rtpg_work, pg->interval * HZ); return; } - spin_lock_irqsave(&pg->rtpg_lock, flags); pg->flags &= ~ALUA_PG_RUN_RTPG; if (err != SCSI_DH_OK) pg->flags &= ~ALUA_PG_RUN_STPG; @@ -792,6 +792,7 @@ static void alua_rtpg_work(struct work_struct *work) if (err == SCSI_DH_RETRY) { pg->flags |= ALUA_PG_RUN_RTPG; pg->interval = 0; + pg->flags &= ~ALUA_PG_RUNNING; spin_unlock_irqrestore(&pg->rtpg_lock, flags); queue_delayed_work(scsidh_aluad, &pg->rtpg_work, msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS)); @@ -809,13 +810,16 @@ static void alua_rtpg_work(struct work_struct *work) qdata->callback_fn(qdata->callback_data, err); kfree(qdata); } + spin_lock_irqsave(&pg->rtpg_lock, flags); + pg->flags &= ~ALUA_PG_RUNNING; + spin_unlock_irqrestore(&pg->rtpg_lock, flags); kref_put(&pg->kref, release_port_group); scsi_device_put(sdev); } static void alua_rtpg_queue(struct alua_port_group *pg, struct scsi_device *sdev, - struct alua_queue_data *qdata) + struct alua_queue_data *qdata, bool force) { int start_queue = 0; unsigned long flags; @@ -836,12 +840,15 @@ static void alua_rtpg_queue(struct alua_port_group *pg, pg->rtpg_sdev = sdev; scsi_device_get(sdev); start_queue = 1; - } + } else if (!(pg->flags & ALUA_PG_RUNNING) && force) + start_queue = 1; + spin_unlock_irqrestore(&pg->rtpg_lock, flags); if (start_queue) - queue_delayed_work(scsidh_aluad, &pg->rtpg_work, - msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS)); + mod_delayed_work(scsidh_aluad, &pg->rtpg_work, + msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS)); + kref_put(&pg->kref, release_port_group); } @@ -874,7 +881,7 @@ static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) complete(&h->init_complete); if (pg) { pg->expiry = 0; - alua_rtpg_queue(pg, sdev, NULL); + alua_rtpg_queue(pg, sdev, NULL, true); kref_put(&pg->kref, release_port_group); } return h->error; @@ -986,7 +993,7 @@ static int alua_activate(struct scsi_device *sdev, pg->flags |= ALUA_OPTIMIZE_STPG; spin_unlock_irqrestore(&pg->rtpg_lock, flags); } - alua_rtpg_queue(pg, sdev, qdata); + alua_rtpg_queue(pg, sdev, qdata, true); kref_put(&pg->kref, release_port_group); out: if (fn) @@ -1000,7 +1007,7 @@ out: * * Check the device status */ -static void alua_check(struct scsi_device *sdev) +static void alua_check(struct scsi_device *sdev, bool force) { struct alua_dh_data *h = sdev->handler_data; struct alua_port_group *pg; @@ -1010,7 +1017,7 @@ static void alua_check(struct scsi_device *sdev) if (pg) { kref_get(&pg->kref); rcu_read_unlock(); - alua_rtpg_queue(pg, sdev, NULL); + alua_rtpg_queue(pg, sdev, NULL, force); kref_put(&pg->kref, release_port_group); } else rcu_read_unlock();