From patchwork Thu Feb 22 08:49:35 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hannes Reinecke X-Patchwork-Id: 10234891 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7D44460224 for ; Thu, 22 Feb 2018 08:49:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8EF5F28A09 for ; Thu, 22 Feb 2018 08:49:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8183428A72; Thu, 22 Feb 2018 08:49:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E097F28A09 for ; Thu, 22 Feb 2018 08:49:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752849AbeBVItz (ORCPT ); Thu, 22 Feb 2018 03:49:55 -0500 Received: from mx2.suse.de ([195.135.220.15]:55702 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752721AbeBVItt (ORCPT ); Thu, 22 Feb 2018 03:49:49 -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 CF85AAE83; Thu, 22 Feb 2018 08:49:47 +0000 (UTC) From: Hannes Reinecke To: "Martin K. Petersen" Cc: James Bottomley , Christoph Hellwig , linux-scsi@vger.kernel.org, Hannes Reinecke , Himanshu Madhani , Quinn Tran , Hannes Reinecke Subject: [PATCH 1/3] qla2xxx: Fixup locking for session deletion Date: Thu, 22 Feb 2018 09:49:35 +0100 Message-Id: <20180222084937.59664-2-hare@suse.de> X-Mailer: git-send-email 2.12.3 In-Reply-To: <20180222084937.59664-1-hare@suse.de> References: <20180222084937.59664-1-hare@suse.de> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Commit d8630bb95f46 ('Serialize session deletion by using work_lock') tries to fixup a deadlock when deleting sessions, but fails to take into account the locking rules. This patch resolves the situation by introducing a separate lock for processing the GNLIST response, and ensures that sess_lock is released before calling qlt_schedule_sess_delete(). Cc: Himanshu Madhani Cc: Quinn Tran Fixes: d8630bb95f46 ("scsi: qla2xxx: Serialize session deletion by using work_lock") Signed-off-by: Hannes Reinecke Acked-by: Himanshu Madhani --- drivers/scsi/qla2xxx/qla_def.h | 4 ++-- drivers/scsi/qla2xxx/qla_init.c | 24 +++++++++++++++--------- drivers/scsi/qla2xxx/qla_os.c | 7 ++++++- drivers/scsi/qla2xxx/qla_target.c | 17 ++++++----------- 4 files changed, 29 insertions(+), 23 deletions(-) diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h index be7d6824581a..3ca4b6a5eddd 100644 --- a/drivers/scsi/qla2xxx/qla_def.h +++ b/drivers/scsi/qla2xxx/qla_def.h @@ -261,9 +261,9 @@ struct name_list_extended { struct get_name_list_extended *l; dma_addr_t ldma; - struct list_head fcports; /* protect by sess_list */ + struct list_head fcports; + spinlock_t fcports_lock; u32 size; - u8 sent; }; /* * Timeout timer counts in seconds diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c index 590aa904fdef..4dd897c2c2b1 100644 --- a/drivers/scsi/qla2xxx/qla_init.c +++ b/drivers/scsi/qla2xxx/qla_init.c @@ -660,8 +660,7 @@ qla24xx_async_gnl_sp_done(void *s, int res) (loop_id & 0x7fff)); } - spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags); - vha->gnl.sent = 0; + spin_lock_irqsave(&vha->gnl.fcports_lock, flags); INIT_LIST_HEAD(&h); fcport = tf = NULL; @@ -670,12 +669,16 @@ qla24xx_async_gnl_sp_done(void *s, int res) list_for_each_entry_safe(fcport, tf, &h, gnl_entry) { list_del_init(&fcport->gnl_entry); + spin_lock(&vha->hw->tgt.sess_lock); fcport->flags &= ~(FCF_ASYNC_SENT | FCF_ASYNC_ACTIVE); + spin_unlock(&vha->hw->tgt.sess_lock); ea.fcport = fcport; qla2x00_fcport_event_handler(vha, &ea); } + spin_unlock_irqrestore(&vha->gnl.fcports_lock, flags); + spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags); /* create new fcport if fw has knowledge of new sessions */ for (i = 0; i < n; i++) { port_id_t id; @@ -727,18 +730,21 @@ int qla24xx_async_gnl(struct scsi_qla_host *vha, fc_port_t *fcport) ql_dbg(ql_dbg_disc, vha, 0x20d9, "Async-gnlist WWPN %8phC \n", fcport->port_name); - spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags); + spin_lock_irqsave(&vha->gnl.fcports_lock, flags); + if (!list_empty(&fcport->gnl_entry)) { + spin_unlock_irqrestore(&vha->gnl.fcports_lock, flags); + rval = QLA_SUCCESS; + goto done; + } + + spin_lock(&vha->hw->tgt.sess_lock); fcport->disc_state = DSC_GNL; fcport->last_rscn_gen = fcport->rscn_gen; fcport->last_login_gen = fcport->login_gen; + spin_unlock(&vha->hw->tgt.sess_lock); list_add_tail(&fcport->gnl_entry, &vha->gnl.fcports); - if (vha->gnl.sent) { - spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags); - return QLA_SUCCESS; - } - vha->gnl.sent = 1; - spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags); + spin_unlock_irqrestore(&vha->gnl.fcports_lock, flags); sp = qla2x00_get_sp(vha, fcport, GFP_KERNEL); if (!sp) diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c index 12ee6e02d146..dc2b188fdce1 100644 --- a/drivers/scsi/qla2xxx/qla_os.c +++ b/drivers/scsi/qla2xxx/qla_os.c @@ -4575,6 +4575,7 @@ struct scsi_qla_host *qla2x00_create_host(struct scsi_host_template *sht, spin_lock_init(&vha->work_lock); spin_lock_init(&vha->cmd_list_lock); + spin_lock_init(&vha->gnl.fcports_lock); init_waitqueue_head(&vha->fcport_waitQ); init_waitqueue_head(&vha->vref_waitq); @@ -4875,6 +4876,8 @@ void qla24xx_create_new_sess(struct scsi_qla_host *vha, struct qla_work_evt *e) } qlt_plogi_ack_unref(vha, pla); } else { + fc_port_t *dfcp = NULL; + spin_lock_irqsave(&vha->hw->tgt.sess_lock, flags); tfcp = qla2x00_find_fcport_by_nportid(vha, &e->u.new_sess.id, 1); @@ -4897,11 +4900,13 @@ void qla24xx_create_new_sess(struct scsi_qla_host *vha, struct qla_work_evt *e) default: fcport->login_pause = 1; tfcp->conflict = fcport; - qlt_schedule_sess_for_deletion(tfcp); + dfcp = tfcp; break; } } spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags); + if (dfcp) + qlt_schedule_sess_for_deletion(tfcp); wwn = wwn_to_u64(fcport->node_name); diff --git a/drivers/scsi/qla2xxx/qla_target.c b/drivers/scsi/qla2xxx/qla_target.c index 3735ebd83012..990ef1183f3a 100644 --- a/drivers/scsi/qla2xxx/qla_target.c +++ b/drivers/scsi/qla2xxx/qla_target.c @@ -1224,10 +1224,10 @@ static void qla24xx_chk_fcp_state(struct fc_port *sess) } } -/* ha->tgt.sess_lock supposed to be held on entry */ void qlt_schedule_sess_for_deletion(struct fc_port *sess) { struct qla_tgt *tgt = sess->tgt; + struct qla_hw_data *ha = sess->vha->hw; unsigned long flags; if (sess->disc_state == DSC_DELETE_PEND) @@ -1244,16 +1244,16 @@ void qlt_schedule_sess_for_deletion(struct fc_port *sess) return; } + spin_lock_irqsave(&ha->tgt.sess_lock, flags); if (sess->deleted == QLA_SESS_DELETED) sess->logout_on_delete = 0; - spin_lock_irqsave(&sess->vha->work_lock, flags); if (sess->deleted == QLA_SESS_DELETION_IN_PROGRESS) { - spin_unlock_irqrestore(&sess->vha->work_lock, flags); + spin_unlock_irqrestore(&ha->tgt.sess_lock, flags); return; } sess->deleted = QLA_SESS_DELETION_IN_PROGRESS; - spin_unlock_irqrestore(&sess->vha->work_lock, flags); + spin_unlock_irqrestore(&ha->tgt.sess_lock, flags); sess->disc_state = DSC_DELETE_PEND; @@ -1262,13 +1262,10 @@ void qlt_schedule_sess_for_deletion(struct fc_port *sess) ql_dbg(ql_dbg_tgt, sess->vha, 0xe001, "Scheduling sess %p for deletion\n", sess); - /* use cancel to push work element through before re-queue */ - cancel_work_sync(&sess->del_work); INIT_WORK(&sess->del_work, qla24xx_delete_sess_fn); - queue_work(sess->vha->hw->wq, &sess->del_work); + WARN_ON(!queue_work(sess->vha->hw->wq, &sess->del_work)); } -/* ha->tgt.sess_lock supposed to be held on entry */ static void qlt_clear_tgt_db(struct qla_tgt *tgt) { struct fc_port *sess; @@ -1451,8 +1448,8 @@ qlt_fc_port_deleted(struct scsi_qla_host *vha, fc_port_t *fcport, int max_gen) ql_dbg(ql_dbg_tgt_mgt, vha, 0xf008, "qla_tgt_fc_port_deleted %p", sess); sess->local = 1; - qlt_schedule_sess_for_deletion(sess); spin_unlock_irqrestore(&vha->hw->tgt.sess_lock, flags); + qlt_schedule_sess_for_deletion(sess); } static inline int test_tgt_sess_count(struct qla_tgt *tgt) @@ -1512,10 +1509,8 @@ int qlt_stop_phase1(struct qla_tgt *tgt) * Lock is needed, because we still can get an incoming packet. */ mutex_lock(&vha->vha_tgt.tgt_mutex); - spin_lock_irqsave(&ha->tgt.sess_lock, flags); tgt->tgt_stop = 1; qlt_clear_tgt_db(tgt); - spin_unlock_irqrestore(&ha->tgt.sess_lock, flags); mutex_unlock(&vha->vha_tgt.tgt_mutex); mutex_unlock(&qla_tgt_mutex);