From patchwork Tue Jan 12 15:40:50 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 8018831 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7AB829F6FA for ; Tue, 12 Jan 2016 15:41:35 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3B014203E5 for ; Tue, 12 Jan 2016 15:41:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 37C15203DC for ; Tue, 12 Jan 2016 15:41:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762805AbcALPlZ (ORCPT ); Tue, 12 Jan 2016 10:41:25 -0500 Received: from mx2.suse.de ([195.135.220.15]:38682 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762804AbcALPlG (ORCPT ); Tue, 12 Jan 2016 10:41:06 -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 D9BFAAD8D; Tue, 12 Jan 2016 15:40:59 +0000 (UTC) From: Hannes Reinecke To: "Martin K. Petersen" Cc: James Bottomley , Christoph Hellwig , Bart von Assche , Ewan Milne , linux-scsi@vger.kernel.org, Hannes Reinecke Subject: [PATCHv2 14/22] scsi_dh_alua: Allow workqueue to run synchronously Date: Tue, 12 Jan 2016 16:40:50 +0100 Message-Id: <1452613258-94084-15-git-send-email-hare@suse.de> X-Mailer: git-send-email 1.8.5.6 In-Reply-To: <1452613258-94084-1-git-send-email-hare@suse.de> References: <1452613258-94084-1-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, 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 Some arrays may only capable of handling one STPG at a time, so this patch adds a singlethreaded workqueue for STPGs to be submitted synchronously. Synchronous STPG can be activated by setting the second module option to '1'. The corresponding entry in multipath.conf would be: hardware_handler "3 alua 1 1" Signed-off-by: Hannes Reinecke --- drivers/scsi/device_handler/scsi_dh_alua.c | 41 ++++++++++++++++++++++++------ 1 file changed, 33 insertions(+), 8 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index 9d56d6a..eb12074 100644 --- a/drivers/scsi/device_handler/scsi_dh_alua.c +++ b/drivers/scsi/device_handler/scsi_dh_alua.c @@ -64,6 +64,7 @@ /* device handler flags */ #define ALUA_OPTIMIZE_STPG 0x01 #define ALUA_RTPG_EXT_HDR_UNSUPP 0x02 +#define ALUA_SYNC_STPG 0x04 /* State machine flags */ #define ALUA_PG_RUN_RTPG 0x10 #define ALUA_PG_RUN_STPG 0x20 @@ -76,6 +77,7 @@ MODULE_PARM_DESC(optimize_stpg, "Allow use of a non-optimized path, rather than static LIST_HEAD(port_group_list); static DEFINE_SPINLOCK(port_group_lock); static struct workqueue_struct *kaluad_wq; +static struct workqueue_struct *kaluad_sync_wq; struct alua_port_group { struct kref kref; @@ -700,6 +702,7 @@ static void alua_rtpg_work(struct work_struct *work) int err = SCSI_DH_OK; struct alua_queue_data *qdata, *tmp; unsigned long flags; + struct workqueue_struct *alua_wq = kaluad_wq; spin_lock_irqsave(&pg->lock, flags); sdev = pg->rtpg_sdev; @@ -709,6 +712,8 @@ static void alua_rtpg_work(struct work_struct *work) spin_unlock_irqrestore(&pg->lock, flags); return; } + if (pg->flags & ALUA_SYNC_STPG) + alua_wq = kaluad_sync_wq; pg->flags |= ALUA_PG_RUNNING; if (pg->flags & ALUA_PG_RUN_RTPG) { spin_unlock_irqrestore(&pg->lock, flags); @@ -717,7 +722,7 @@ static void alua_rtpg_work(struct work_struct *work) if (err == SCSI_DH_RETRY) { pg->flags &= ~ALUA_PG_RUNNING; spin_unlock_irqrestore(&pg->lock, flags); - queue_delayed_work(kaluad_wq, &pg->rtpg_work, + queue_delayed_work(alua_wq, &pg->rtpg_work, pg->interval * HZ); return; } @@ -735,7 +740,7 @@ static void alua_rtpg_work(struct work_struct *work) pg->interval = 0; pg->flags &= ~ALUA_PG_RUNNING; spin_unlock_irqrestore(&pg->lock, flags); - queue_delayed_work(kaluad_wq, &pg->rtpg_work, + queue_delayed_work(alua_wq, &pg->rtpg_work, pg->interval * HZ); return; } @@ -764,6 +769,7 @@ static void alua_rtpg_queue(struct alua_port_group *pg, { int start_queue = 0; unsigned long flags; + struct workqueue_struct *alua_wq = kaluad_wq; if (!pg) return; @@ -781,10 +787,12 @@ static void alua_rtpg_queue(struct alua_port_group *pg, scsi_device_get(sdev); start_queue = 1; } + if (pg->flags & ALUA_SYNC_STPG) + alua_wq = kaluad_sync_wq; spin_unlock_irqrestore(&pg->lock, flags); if (start_queue && - !queue_delayed_work(kaluad_wq, &pg->rtpg_work, + !queue_delayed_work(alua_wq, &pg->rtpg_work, msecs_to_jiffies(ALUA_RTPG_DELAY_MSECS))) { scsi_device_put(sdev); kref_put(&pg->kref, release_port_group); @@ -811,30 +819,36 @@ static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h) return err; } /* - * alua_set_params - set/unset the optimize flag + * alua_set_params - set/unset the optimize and sync flag * @sdev: device on the path to be activated * params - parameters in the following format * "no_of_params\0param1\0param2\0param3\0...\0" * For example, to set the flag pass the following parameters * from multipath.conf - * hardware_handler "2 alua 1" + * hardware_handler "3 alua 1 1" */ static int alua_set_params(struct scsi_device *sdev, const char *params) { struct alua_dh_data *h = sdev->handler_data; struct alua_port_group *pg = NULL; - unsigned int optimize = 0, argc; + unsigned int optimize = 0, sync = 0, argc; const char *p = params; int result = SCSI_DH_OK; unsigned long flags; - if ((sscanf(params, "%u", &argc) != 1) || (argc != 1)) + if ((sscanf(params, "%u", &argc) != 1) || (argc > 2)) return -EINVAL; while (*p++) ; if ((sscanf(p, "%u", &optimize) != 1) || (optimize > 1)) return -EINVAL; + if (argc == 2) { + while (*p++) + ; + if ((sscanf(p, "%u", &sync) != 1) || (sync > 1)) + return -EINVAL; + } rcu_read_lock(); pg = rcu_dereference(h->pg); @@ -846,7 +860,11 @@ static int alua_set_params(struct scsi_device *sdev, const char *params) if (optimize) pg->flags |= ALUA_OPTIMIZE_STPG; else - pg->flags |= ~ALUA_OPTIMIZE_STPG; + pg->flags &= ~ALUA_OPTIMIZE_STPG; + if (sync) + pg->flags |= ALUA_SYNC_STPG; + else + pg->flags &= ~ALUA_SYNC_STPG; spin_unlock_irqrestore(&pg->lock, flags); rcu_read_unlock(); @@ -1010,10 +1028,16 @@ static int __init alua_init(void) /* Temporary failure, bypass */ return SCSI_DH_DEV_TEMP_BUSY; } + kaluad_sync_wq = create_workqueue("kaluad_sync"); + if (!kaluad_sync_wq) { + destroy_workqueue(kaluad_wq); + return SCSI_DH_DEV_TEMP_BUSY; + } r = scsi_register_device_handler(&alua_dh); if (r != 0) { printk(KERN_ERR "%s: Failed to register scsi device handler", ALUA_DH_NAME); + destroy_workqueue(kaluad_sync_wq); destroy_workqueue(kaluad_wq); } return r; @@ -1022,6 +1046,7 @@ static int __init alua_init(void) static void __exit alua_exit(void) { scsi_unregister_device_handler(&alua_dh); + destroy_workqueue(kaluad_sync_wq); destroy_workqueue(kaluad_wq); }