From patchwork Mon Dec 20 11:21:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: chenxiang X-Patchwork-Id: 12687663 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2957CC4332F for ; Mon, 20 Dec 2021 11:27:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231797AbhLTL1D (ORCPT ); Mon, 20 Dec 2021 06:27:03 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:28333 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231803AbhLTL0w (ORCPT ); Mon, 20 Dec 2021 06:26:52 -0500 Received: from dggeme756-chm.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4JHcjc4nT0zbjPq; Mon, 20 Dec 2021 19:26:28 +0800 (CST) Received: from localhost.localdomain (10.69.192.58) by dggeme756-chm.china.huawei.com (10.3.19.102) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2308.20; Mon, 20 Dec 2021 19:26:50 +0800 From: chenxiang To: , CC: , , , Xiang Chen Subject: [PATCH v2 12/15] scsi: libsas: Defer works of new phys during suspend Date: Mon, 20 Dec 2021 19:21:35 +0800 Message-ID: <1639999298-244569-13-git-send-email-chenxiang66@hisilicon.com> X-Mailer: git-send-email 2.8.1 In-Reply-To: <1639999298-244569-1-git-send-email-chenxiang66@hisilicon.com> References: <1639999298-244569-1-git-send-email-chenxiang66@hisilicon.com> MIME-Version: 1.0 X-Originating-IP: [10.69.192.58] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To dggeme756-chm.china.huawei.com (10.3.19.102) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org From: Xiang Chen During the process of event PORT_BYTES_DMAED, it queues work DISCE_DISCOVER_DOMAIN and then flush workqueue ha->disco_q. If new phyup occurs during resming SAS controller, the work PORTE_BYTES_DMAED of new phys occurs before suspended phys', then work DISCE_DISCOVER_DOMAIN of new phy requires the active of SAS controller (It requires to resume SAS controller by function scsi_sysfs_add_sdev() and some other functions such as function add_device_link()). But the active of SAS controller requires the complete of work PORTE_BYTES_DMAED of suspended phys while it is blocked by new phy's work on ha->event_q. So there is a deadlock and it is released only after resume timeout. To solve the issue, defer works of new phys during suspend and queue those defer works after SAS controller becomes active. Signed-off-by: Xiang Chen Reviewed-by: John Garry --- drivers/scsi/libsas/sas_event.c | 24 ++++++++++++++++++++++++ drivers/scsi/libsas/sas_init.c | 1 + 2 files changed, 25 insertions(+) diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c index 01e544ca518a..626ef96b9348 100644 --- a/drivers/scsi/libsas/sas_event.c +++ b/drivers/scsi/libsas/sas_event.c @@ -139,6 +139,24 @@ static void sas_phy_event_worker(struct work_struct *work) sas_free_event(ev); } +/* defer works of new phys during suspend */ +static bool sas_defer_event(struct asd_sas_phy *phy, struct asd_sas_event *ev) +{ + struct sas_ha_struct *ha = phy->ha; + unsigned long flags; + bool deferred = false; + + spin_lock_irqsave(&ha->lock, flags); + if (test_bit(SAS_HA_RESUMING, &ha->state) && !phy->suspended) { + struct sas_work *sw = &ev->work; + + list_add_tail(&sw->drain_node, &ha->defer_q); + deferred = true; + } + spin_unlock_irqrestore(&ha->lock, flags); + return deferred; +} + int sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event, gfp_t gfp_flags) { @@ -154,6 +172,9 @@ int sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event, INIT_SAS_EVENT(ev, sas_port_event_worker, phy, event); + if (sas_defer_event(phy, ev)) + return 0; + ret = sas_queue_event(event, &ev->work, ha); if (ret != 1) sas_free_event(ev); @@ -177,6 +198,9 @@ int sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event, INIT_SAS_EVENT(ev, sas_phy_event_worker, phy, event); + if (sas_defer_event(phy, ev)) + return 0; + ret = sas_queue_event(event, &ev->work, ha); if (ret != 1) sas_free_event(ev); diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c index 069e40fc8411..dc35f0f8eae3 100644 --- a/drivers/scsi/libsas/sas_init.c +++ b/drivers/scsi/libsas/sas_init.c @@ -446,6 +446,7 @@ static void _sas_resume_ha(struct sas_ha_struct *ha, bool drain) sas_drain_work(ha); clear_bit(SAS_HA_RESUMING, &ha->state); + sas_queue_deferred_work(ha); /* send event PORTE_BROADCAST_RCVD to identify some new inserted * disks for expander */