From patchwork Wed Jul 12 18:05:15 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Tee X-Patchwork-Id: 13310797 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 14CA3EB64DA for ; Wed, 12 Jul 2023 17:53:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232441AbjGLRx4 (ORCPT ); Wed, 12 Jul 2023 13:53:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232555AbjGLRxp (ORCPT ); Wed, 12 Jul 2023 13:53:45 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A46A52100 for ; Wed, 12 Jul 2023 10:53:41 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id d9443c01a7336-1b9d9cbcc70so6559695ad.0 for ; Wed, 12 Jul 2023 10:53:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1689184421; x=1689789221; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=e19eQPaQE2yvpbV9jflN87bZC5C/rFCgbTaQAV3M7c8=; b=YrAfI0BJlQWzmcOEmEv54PcHwISdKE9J1wwGV4GTRbkHSKSjZR942dSxaG9tMJaCON P0R2RPBXLTOg4+hBhvz3powvOqpwnUL1cEbnI+yP3X1eatUcsnLaNLx2G/eXNZYWVZh6 FZ1trlVIrk+EyDNZ4zPiiwztLVC641P/9lTIlWkUZ9BYsSrklECBHm3O90DRBbaMKFdX /yNek0AlM9Q2GkAG+9rBibhRh0GsuqZt7uzCe6+/luy0gab/MgiIdobRqADZAzJPKETA svDfi0YehI2g05f1q36e42gIEQLeQntSPwrMKHpmjLvOdodDNJysF+MS5iU6dNAwLu7K isvA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689184421; x=1689789221; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=e19eQPaQE2yvpbV9jflN87bZC5C/rFCgbTaQAV3M7c8=; b=B7sUH7FQVnhJLj7I3fNjEMYHHAlYvo1qRjw2fQcDUiQGIlIRlp/jXMCYdlP0v8Kk4H 2hemMCPCSq9VGtsoPkDU7tHNCC6cLWOdv4KV+fyIUCjgnYXV+HWQS2JLamp6JomjLmMn 8hl9U8H/jj8xDkTkfqWmeuuebExFBuLyh5fAyRbELBgzUdyHkjyrH+q1O54LelLj3lqs zV7RfNq8Ponbl6KDMC3X+ImBtMHPSVdYscXTf+4kyEn+tmJvD1XoC0Lt6tD0G+CPy1K8 +9NRYOq4polC/toJIwyyZmtqZ78cu5lkrJZ1TBTVqcgJYY6VUw8RITO1gwT71ifbFY/4 KerQ== X-Gm-Message-State: ABy/qLbEaOcCLanHfV534zPVGNn3lfm28QN2XDJz9S3bKAuQd0VpzNZq 2Y6dvocdTAaDY2Bu9hO3xv7J9gq3ykw= X-Google-Smtp-Source: APBJJlGjwWGH3M4JO0W6a2Dbl1Mb4IPuFt0mImBu28DrqtUBTKt9UlZ9nCvcKvDTMfWg2bmdnG/ZIA== X-Received: by 2002:a17:903:22ca:b0:1b8:b0c4:2e3d with SMTP id y10-20020a17090322ca00b001b8b0c42e3dmr81095plg.4.1689184420441; Wed, 12 Jul 2023 10:53:40 -0700 (PDT) Received: from dhcp-10-231-55-133.dhcp.broadcom.net ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id d11-20020a170902b70b00b001b898595be7sm4218459pls.291.2023.07.12.10.53.39 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 12 Jul 2023 10:53:40 -0700 (PDT) From: Justin Tee To: linux-scsi@vger.kernel.org Cc: jsmart2021@gmail.com, justin.tee@broadcom.com, Justin Tee Subject: [PATCH 05/12] lpfc: Revise ndlp kref handling for dev_loss_tmo_callbk and lpfc_drop_node Date: Wed, 12 Jul 2023 11:05:15 -0700 Message-Id: <20230712180522.112722-6-justintee8345@gmail.com> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20230712180522.112722-1-justintee8345@gmail.com> References: <20230712180522.112722-1-justintee8345@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org The ndlp kref count implementation in lpfc_dev_loss_tmo_callbk removes the initial node reference when a vport is unloading. When lpfc_cleanup sends a DEVICE_RM event and is in NPR state, the driver calls lpfc_drop_node. Subsequently, lpfc_drop_node also removes an ndlp kref thinking it is the initial reference. This unintentionally introduces an extra kref decrement on the ndlp object. Fix by using the NLP_DROPPED node flag in lpfc_dev_loss_tmo_callbk and lpfc_drop_node to coordinate the removal of the initial node reference. In lpfc_dev_loss_tmo_callbk, remove the SCSI transport reference provided the node is registered in the dev_loss context because the driver cannot call the SCSI transport in dev_loss context or afterwards. And, have lpfc_drop_node not remove a reference if another thread is acting or has already acted on it. Signed-off-by: Justin Tee --- drivers/scsi/lpfc/lpfc_hbadisc.c | 70 +++++++++++++++++++++----------- drivers/scsi/lpfc/lpfc_nvme.c | 5 ++- 2 files changed, 50 insertions(+), 25 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c index b4303254744a..388a481c8118 100644 --- a/drivers/scsi/lpfc/lpfc_hbadisc.c +++ b/drivers/scsi/lpfc/lpfc_hbadisc.c @@ -169,29 +169,44 @@ lpfc_dev_loss_tmo_callbk(struct fc_rport *rport) lpfc_printf_vlog(ndlp->vport, KERN_INFO, LOG_NODE, "3181 dev_loss_callbk x%06x, rport x%px flg x%x " - "load_flag x%x refcnt %d state %d xpt x%x\n", + "load_flag x%x refcnt %u state %d xpt x%x\n", ndlp->nlp_DID, ndlp->rport, ndlp->nlp_flag, vport->load_flag, kref_read(&ndlp->kref), ndlp->nlp_state, ndlp->fc4_xpt_flags); - /* Don't schedule a worker thread event if the vport is going down. - * The teardown process cleans up the node via lpfc_drop_node. - */ + /* Don't schedule a worker thread event if the vport is going down. */ if (vport->load_flag & FC_UNLOADING) { - ((struct lpfc_rport_data *)rport->dd_data)->pnode = NULL; + spin_lock_irqsave(&ndlp->lock, iflags); ndlp->rport = NULL; - ndlp->fc4_xpt_flags &= ~SCSI_XPT_REGD; - /* clear the NLP_XPT_REGD if the node is not registered - * with nvme-fc + /* The scsi_transport is done with the rport so lpfc cannot + * call to unregister. Remove the scsi transport reference + * and clean up the SCSI transport node details. */ - if (ndlp->fc4_xpt_flags == NLP_XPT_REGD) - ndlp->fc4_xpt_flags &= ~NLP_XPT_REGD; + if (ndlp->fc4_xpt_flags & (NLP_XPT_REGD | SCSI_XPT_REGD)) { + ndlp->fc4_xpt_flags &= ~SCSI_XPT_REGD; - /* Remove the node reference from remote_port_add now. - * The driver will not call remote_port_delete. + /* NVME transport-registered rports need the + * NLP_XPT_REGD flag to complete an unregister. + */ + if (!(ndlp->fc4_xpt_flags & NVME_XPT_REGD)) + ndlp->fc4_xpt_flags &= ~NLP_XPT_REGD; + spin_unlock_irqrestore(&ndlp->lock, iflags); + lpfc_nlp_put(ndlp); + spin_lock_irqsave(&ndlp->lock, iflags); + } + + /* Only 1 thread can drop the initial node reference. If + * another thread has set NLP_DROPPED, this thread is done. */ - lpfc_nlp_put(ndlp); + if (!(ndlp->nlp_flag & NLP_DROPPED)) { + ndlp->nlp_flag |= NLP_DROPPED; + spin_unlock_irqrestore(&ndlp->lock, iflags); + lpfc_nlp_put(ndlp); + spin_lock_irqsave(&ndlp->lock, iflags); + } + + spin_unlock_irqrestore(&ndlp->lock, iflags); return; } @@ -4686,7 +4701,8 @@ lpfc_nlp_unreg_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp) spin_lock_irqsave(&ndlp->lock, iflags); if (!(ndlp->fc4_xpt_flags & NLP_XPT_REGD)) { spin_unlock_irqrestore(&ndlp->lock, iflags); - lpfc_printf_vlog(vport, KERN_INFO, LOG_SLI, + lpfc_printf_vlog(vport, KERN_INFO, + LOG_ELS | LOG_NODE | LOG_DISCOVERY, "0999 %s Not regd: ndlp x%px rport x%px DID " "x%x FLG x%x XPT x%x\n", __func__, ndlp, ndlp->rport, ndlp->nlp_DID, @@ -4702,9 +4718,10 @@ lpfc_nlp_unreg_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp) vport->phba->nport_event_cnt++; lpfc_unregister_remote_port(ndlp); } else if (!ndlp->rport) { - lpfc_printf_vlog(vport, KERN_INFO, LOG_SLI, + lpfc_printf_vlog(vport, KERN_INFO, + LOG_ELS | LOG_NODE | LOG_DISCOVERY, "1999 %s NDLP in devloss x%px DID x%x FLG x%x" - " XPT x%x refcnt %d\n", + " XPT x%x refcnt %u\n", __func__, ndlp, ndlp->nlp_DID, ndlp->nlp_flag, ndlp->fc4_xpt_flags, kref_read(&ndlp->kref)); @@ -4954,22 +4971,29 @@ lpfc_drop_node(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp) { /* * Use of lpfc_drop_node and UNUSED list: lpfc_drop_node should - * be used if we wish to issue the "last" lpfc_nlp_put() to remove - * the ndlp from the vport. The ndlp marked as UNUSED on the list - * until ALL other outstanding threads have completed. We check - * that the ndlp not already in the UNUSED state before we proceed. + * be used when lpfc wants to remove the "last" lpfc_nlp_put() to + * release the ndlp from the vport when conditions are correct. */ if (ndlp->nlp_state == NLP_STE_UNUSED_NODE) return; lpfc_nlp_set_state(vport, ndlp, NLP_STE_UNUSED_NODE); - ndlp->nlp_flag |= NLP_DROPPED; if (vport->phba->sli_rev == LPFC_SLI_REV4) { lpfc_cleanup_vports_rrqs(vport, ndlp); lpfc_unreg_rpi(vport, ndlp); } - lpfc_nlp_put(ndlp); - return; + /* NLP_DROPPED means another thread already removed the initial + * reference from lpfc_nlp_init. If set, don't drop it again and + * introduce an imbalance. + */ + spin_lock_irq(&ndlp->lock); + if (!(ndlp->nlp_flag & NLP_DROPPED)) { + ndlp->nlp_flag |= NLP_DROPPED; + spin_unlock_irq(&ndlp->lock); + lpfc_nlp_put(ndlp); + return; + } + spin_unlock_irq(&ndlp->lock); } /* diff --git a/drivers/scsi/lpfc/lpfc_nvme.c b/drivers/scsi/lpfc/lpfc_nvme.c index 3ee5cde481f3..39acbcb7ec66 100644 --- a/drivers/scsi/lpfc/lpfc_nvme.c +++ b/drivers/scsi/lpfc/lpfc_nvme.c @@ -2503,8 +2503,9 @@ lpfc_nvme_register_port(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp) lpfc_printf_vlog(vport, KERN_ERR, LOG_TRACE_EVENT, "6031 RemotePort Registration failed " - "err: %d, DID x%06x\n", - ret, ndlp->nlp_DID); + "err: %d, DID x%06x ref %u\n", + ret, ndlp->nlp_DID, kref_read(&ndlp->kref)); + lpfc_nlp_put(ndlp); } return ret;