From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 64CA8C43603 for ; Wed, 4 Dec 2019 18:00:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31C022086D for ; Wed, 4 Dec 2019 18:00:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575482425; bh=+dhwOKoTwp3bRqCgfQD7aUTOSt0rDYzemDVM9IYjrdA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=P22yzy9zcFv61k19jFCF1ZQtCdsCYk9ZbMnAADVho38zzIzO/p7B0q7HTPLkyHXoP XqkNzJLH/JXi8ekVPVp+bKmyVATgUg8B8kYqZ4tg2gnJLYAFNiI5CRuf7YSlwtnBiE UC3t71FVhUhP4j5kO+jbemL+Arz25PyinUHHNa5E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729341AbfLDSAY (ORCPT ); Wed, 4 Dec 2019 13:00:24 -0500 Received: from mail.kernel.org ([198.145.29.99]:38766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729325AbfLDSAW (ORCPT ); Wed, 4 Dec 2019 13:00:22 -0500 Received: from localhost (unknown [217.68.49.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CF7452081B; Wed, 4 Dec 2019 18:00:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1575482421; bh=+dhwOKoTwp3bRqCgfQD7aUTOSt0rDYzemDVM9IYjrdA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lC7xblT/A9rvbptgO6YfhH2oOxZ0Q9X3Lr4TjVXP8KQ/w5ssmdjNMalHrT03qIXhu CltMUR/OF7NPDoJLldfOYGNmGFzbdpfsKllH0RbnHNTB0k3qxfyIngCL18hZAM4ORo grQi/yIPAs37S3cXqwUXN/ImJJ8Q0nbJXP/1FlP0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Anatoliy Glagolev , Himanshu Madhani , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.4 44/92] scsi: qla2xxx: deadlock by configfs_depend_item Date: Wed, 4 Dec 2019 18:49:44 +0100 Message-Id: <20191204174333.159782454@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191204174327.215426506@linuxfoundation.org> References: <20191204174327.215426506@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Anatoliy Glagolev [ Upstream commit 17b18eaa6f59044a5172db7d07149e31ede0f920 ] The intent of invoking configfs_depend_item in commit 7474f52a82d51 ("tcm_qla2xxx: Perform configfs depend/undepend for base_tpg") was to prevent a physical Fibre Channel port removal when virtual (NPIV) ports announced through that physical port are active. The change does not work as expected: it makes enabled physical port dependent on target configfs subsystem (the port's parent), something the configfs guarantees anyway. Besides, scheduling work in a worker thread and waiting for the work's completion is not really a valid workaround for the requirement not to call configfs_depend_item from a configfs callback: the call occasionally deadlocks. Thus, removing configfs_depend_item calls does not break anything and fixes the deadlock problem. Signed-off-by: Anatoliy Glagolev Acked-by: Himanshu Madhani Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/qla2xxx/tcm_qla2xxx.c | 48 +++++------------------------- drivers/scsi/qla2xxx/tcm_qla2xxx.h | 3 -- 2 files changed, 8 insertions(+), 43 deletions(-) diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c index 81af294f15a7d..b1233ce6cb475 100644 --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c @@ -793,38 +793,14 @@ static ssize_t tcm_qla2xxx_tpg_enable_show(struct config_item *item, atomic_read(&tpg->lport_tpg_enabled)); } -static void tcm_qla2xxx_depend_tpg(struct work_struct *work) -{ - struct tcm_qla2xxx_tpg *base_tpg = container_of(work, - struct tcm_qla2xxx_tpg, tpg_base_work); - struct se_portal_group *se_tpg = &base_tpg->se_tpg; - struct scsi_qla_host *base_vha = base_tpg->lport->qla_vha; - - if (!target_depend_item(&se_tpg->tpg_group.cg_item)) { - atomic_set(&base_tpg->lport_tpg_enabled, 1); - qlt_enable_vha(base_vha); - } - complete(&base_tpg->tpg_base_comp); -} - -static void tcm_qla2xxx_undepend_tpg(struct work_struct *work) -{ - struct tcm_qla2xxx_tpg *base_tpg = container_of(work, - struct tcm_qla2xxx_tpg, tpg_base_work); - struct se_portal_group *se_tpg = &base_tpg->se_tpg; - struct scsi_qla_host *base_vha = base_tpg->lport->qla_vha; - - if (!qlt_stop_phase1(base_vha->vha_tgt.qla_tgt)) { - atomic_set(&base_tpg->lport_tpg_enabled, 0); - target_undepend_item(&se_tpg->tpg_group.cg_item); - } - complete(&base_tpg->tpg_base_comp); -} - static ssize_t tcm_qla2xxx_tpg_enable_store(struct config_item *item, const char *page, size_t count) { struct se_portal_group *se_tpg = to_tpg(item); + struct se_wwn *se_wwn = se_tpg->se_tpg_wwn; + struct tcm_qla2xxx_lport *lport = container_of(se_wwn, + struct tcm_qla2xxx_lport, lport_wwn); + struct scsi_qla_host *vha = lport->qla_vha; struct tcm_qla2xxx_tpg *tpg = container_of(se_tpg, struct tcm_qla2xxx_tpg, se_tpg); unsigned long op; @@ -843,24 +819,16 @@ static ssize_t tcm_qla2xxx_tpg_enable_store(struct config_item *item, if (atomic_read(&tpg->lport_tpg_enabled)) return -EEXIST; - INIT_WORK(&tpg->tpg_base_work, tcm_qla2xxx_depend_tpg); + atomic_set(&tpg->lport_tpg_enabled, 1); + qlt_enable_vha(vha); } else { if (!atomic_read(&tpg->lport_tpg_enabled)) return count; - INIT_WORK(&tpg->tpg_base_work, tcm_qla2xxx_undepend_tpg); + atomic_set(&tpg->lport_tpg_enabled, 0); + qlt_stop_phase1(vha->vha_tgt.qla_tgt); } - init_completion(&tpg->tpg_base_comp); - schedule_work(&tpg->tpg_base_work); - wait_for_completion(&tpg->tpg_base_comp); - if (op) { - if (!atomic_read(&tpg->lport_tpg_enabled)) - return -ENODEV; - } else { - if (atomic_read(&tpg->lport_tpg_enabled)) - return -EPERM; - } return count; } diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.h b/drivers/scsi/qla2xxx/tcm_qla2xxx.h index 3bbf4cb6fd97e..344f4eab5403c 100644 --- a/drivers/scsi/qla2xxx/tcm_qla2xxx.h +++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.h @@ -47,9 +47,6 @@ struct tcm_qla2xxx_tpg { struct tcm_qla2xxx_tpg_attrib tpg_attrib; /* Returned by tcm_qla2xxx_make_tpg() */ struct se_portal_group se_tpg; - /* Items for dealing with configfs_depend_item */ - struct completion tpg_base_comp; - struct work_struct tpg_base_work; }; struct tcm_qla2xxx_fc_loopid { -- 2.20.1