From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Reinecke Subject: [PATCH 14/23] scsi_dh_alua: Allow workqueue to run synchronously Date: Mon, 8 Feb 2016 15:34:37 +0100 Message-ID: <1454942086-128704-15-git-send-email-hare@suse.de> References: <1454942086-128704-1-git-send-email-hare@suse.de> Return-path: Received: from mx2.suse.de ([195.135.220.15]:42699 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752739AbcBHOey (ORCPT ); Mon, 8 Feb 2016 09:34:54 -0500 In-Reply-To: <1454942086-128704-1-git-send-email-hare@suse.de> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Martin K. Petersen" Cc: Christoph Hellwig , Bart van Assche , James Bottomley , linux-scsi@vger.kernel.org, Ewan Milne , Hannes Reinecke 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. Reviewed-by: Christoph Hellwig Signed-off-by: Hannes Reinecke --- drivers/scsi/device_handler/scsi_dh_alua.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c index 901768f..6c578e9 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; @@ -688,6 +690,7 @@ 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; @@ -697,6 +700,8 @@ 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) { pg->flags &= ~ALUA_PG_RUN_RTPG; @@ -707,7 +712,7 @@ static void alua_rtpg_work(struct work_struct *work) pg->flags &= ~ALUA_PG_RUNNING; pg->flags |= ALUA_PG_RUN_RTPG; 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; } @@ -724,7 +729,7 @@ 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; } @@ -753,6 +758,7 @@ 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; @@ -770,10 +776,12 @@ 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); @@ -992,10 +1000,16 @@ 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; @@ -1004,6 +1018,7 @@ 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); } -- 1.8.5.6