From 894bb17f0cb07a6503d096dbbd156e38a3640822 Mon Sep 17 00:00:00 2001 From: James Smart Date: Wed, 14 Aug 2019 16:56:52 -0700 Subject: [PATCH] scsi: lpfc: Fix deadlock on host_lock during cable pulls During cable pull testing a deadlock was seen between lpfc_nlp_counters() vs lpfc_mbox_process_link_up() vs lpfc_work_list_done(). They are all waiting on the shost->host_lock. Issue is all of these cases raise irq when taking out the lock but use spin_unlock_irq() when unlocking. The unlock path is will unconditionally re-enable interrupts in cases where irq state should be preserved. The re-enablement allowed the other paths to execute which then causes the deadlock. Fix by converting the lock/unlock to irqsave/irqrestore. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Signed-off-by: Martin K. Petersen --- drivers/scsi/lpfc/lpfc_hbadisc.c | 47 ++++++++++++++++++-------------- 1 file changed, 26 insertions(+), 21 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c index 22b6fd08e7f5..c8d14709343f 100644 --- a/drivers/scsi/lpfc/lpfc_hbadisc.c +++ b/drivers/scsi/lpfc/lpfc_hbadisc.c @@ -118,6 +118,7 @@ lpfc_dev_loss_tmo_callbk(struct fc_rport *rport) struct lpfc_work_evt *evtp; int put_node; int put_rport; + unsigned long iflags; rdata = rport->dd_data; ndlp = rdata->pnode; @@ -170,22 +171,22 @@ lpfc_dev_loss_tmo_callbk(struct fc_rport *rport) } shost = lpfc_shost_from_vport(vport); - spin_lock_irq(shost->host_lock); + spin_lock_irqsave(shost->host_lock, iflags); ndlp->nlp_flag |= NLP_IN_DEV_LOSS; - spin_unlock_irq(shost->host_lock); + spin_unlock_irqrestore(shost->host_lock, iflags); /* We need to hold the node by incrementing the reference * count until this queued work is done */ evtp->evt_arg1 = lpfc_nlp_get(ndlp); - spin_lock_irq(&phba->hbalock); + spin_lock_irqsave(&phba->hbalock, iflags); if (evtp->evt_arg1) { evtp->evt = LPFC_EVT_DEV_LOSS; list_add_tail(&evtp->evt_listp, &phba->work_list); lpfc_worker_wake_up(phba); } - spin_unlock_irq(&phba->hbalock); + spin_unlock_irqrestore(&phba->hbalock, iflags); return; } @@ -212,14 +213,15 @@ lpfc_dev_loss_tmo_handler(struct lpfc_nodelist *ndlp) int put_node; int warn_on = 0; int fcf_inuse = 0; + unsigned long iflags; rport = ndlp->rport; vport = ndlp->vport; shost = lpfc_shost_from_vport(vport); - spin_lock_irq(shost->host_lock); + spin_lock_irqsave(shost->host_lock, iflags); ndlp->nlp_flag &= ~NLP_IN_DEV_LOSS; - spin_unlock_irq(shost->host_lock); + spin_unlock_irqrestore(shost->host_lock, iflags); if (!rport) return fcf_inuse; @@ -3115,8 +3117,9 @@ lpfc_mbx_process_link_up(struct lpfc_hba *phba, struct lpfc_mbx_read_top *la) int rc; struct fcf_record *fcf_record; uint32_t fc_flags = 0; + unsigned long iflags; - spin_lock_irq(&phba->hbalock); + spin_lock_irqsave(&phba->hbalock, iflags); phba->fc_linkspeed = bf_get(lpfc_mbx_read_top_link_spd, la); if (!(phba->hba_flag & HBA_FCOE_MODE)) { @@ -3213,12 +3216,12 @@ lpfc_mbx_process_link_up(struct lpfc_hba *phba, struct lpfc_mbx_read_top *la) vport->fc_myDID = phba->fc_pref_DID; fc_flags |= FC_LBIT; } - spin_unlock_irq(&phba->hbalock); + spin_unlock_irqrestore(&phba->hbalock, iflags); if (fc_flags) { - spin_lock_irq(shost->host_lock); + spin_lock_irqsave(shost->host_lock, iflags); vport->fc_flag |= fc_flags; - spin_unlock_irq(shost->host_lock); + spin_unlock_irqrestore(shost->host_lock, iflags); } lpfc_linkup(phba); @@ -3292,22 +3295,22 @@ lpfc_mbx_process_link_up(struct lpfc_hba *phba, struct lpfc_mbx_read_top *la) * The driver is expected to do FIP/FCF. Call the port * and get the FCF Table. */ - spin_lock_irq(&phba->hbalock); + spin_lock_irqsave(&phba->hbalock, iflags); if (phba->hba_flag & FCF_TS_INPROG) { - spin_unlock_irq(&phba->hbalock); + spin_unlock_irqrestore(&phba->hbalock, iflags); return; } /* This is the initial FCF discovery scan */ phba->fcf.fcf_flag |= FCF_INIT_DISC; - spin_unlock_irq(&phba->hbalock); + spin_unlock_irqrestore(&phba->hbalock, iflags); lpfc_printf_log(phba, KERN_INFO, LOG_FIP | LOG_DISCOVERY, "2778 Start FCF table scan at linkup\n"); rc = lpfc_sli4_fcf_scan_read_fcf_rec(phba, LPFC_FCOE_FCF_GET_FIRST); if (rc) { - spin_lock_irq(&phba->hbalock); + spin_lock_irqsave(&phba->hbalock, iflags); phba->fcf.fcf_flag &= ~FCF_INIT_DISC; - spin_unlock_irq(&phba->hbalock); + spin_unlock_irqrestore(&phba->hbalock, iflags); goto out; } /* Reset FCF roundrobin bmask for new discovery */ @@ -3366,6 +3369,7 @@ lpfc_mbx_cmpl_read_topology(struct lpfc_hba *phba, LPFC_MBOXQ_t *pmb) MAILBOX_t *mb = &pmb->u.mb; struct lpfc_dmabuf *mp = (struct lpfc_dmabuf *)(pmb->ctx_buf); uint8_t attn_type; + unsigned long iflags; /* Unblock ELS traffic */ pring = lpfc_phba_elsring(phba); @@ -3387,12 +3391,12 @@ lpfc_mbx_cmpl_read_topology(struct lpfc_hba *phba, LPFC_MBOXQ_t *pmb) memcpy(&phba->alpa_map[0], mp->virt, 128); - spin_lock_irq(shost->host_lock); + spin_lock_irqsave(shost->host_lock, iflags); if (bf_get(lpfc_mbx_read_top_pb, la)) vport->fc_flag |= FC_BYPASSED_MODE; else vport->fc_flag &= ~FC_BYPASSED_MODE; - spin_unlock_irq(shost->host_lock); + spin_unlock_irqrestore(shost->host_lock, iflags); if (phba->fc_eventTag <= la->eventTag) { phba->fc_stat.LinkMultiEvent++; @@ -3403,12 +3407,12 @@ lpfc_mbx_cmpl_read_topology(struct lpfc_hba *phba, LPFC_MBOXQ_t *pmb) phba->fc_eventTag = la->eventTag; if (phba->sli_rev < LPFC_SLI_REV4) { - spin_lock_irq(&phba->hbalock); + spin_lock_irqsave(&phba->hbalock, iflags); if (bf_get(lpfc_mbx_read_top_mm, la)) phba->sli.sli_flag |= LPFC_MENLO_MAINT; else phba->sli.sli_flag &= ~LPFC_MENLO_MAINT; - spin_unlock_irq(&phba->hbalock); + spin_unlock_irqrestore(&phba->hbalock, iflags); } phba->link_events++; @@ -4196,8 +4200,9 @@ static void lpfc_nlp_counters(struct lpfc_vport *vport, int state, int count) { struct Scsi_Host *shost = lpfc_shost_from_vport(vport); + unsigned long iflags; - spin_lock_irq(shost->host_lock); + spin_lock_irqsave(shost->host_lock, iflags); switch (state) { case NLP_STE_UNUSED_NODE: vport->fc_unused_cnt += count; @@ -4227,7 +4232,7 @@ lpfc_nlp_counters(struct lpfc_vport *vport, int state, int count) vport->fc_npr_cnt += count; break; } - spin_unlock_irq(shost->host_lock); + spin_unlock_irqrestore(shost->host_lock, iflags); } static void -- 2.45.2