scsi: lpfc: Fix nvmet issues when link bounce under IO load

Various null pointer dereference and general protection fault panics occur
when there is a link bounce under load. There are a large number of "error"
message 6413 indicating "bad release".

The issues resolve to list corruptions due to missing or inconsistent lock
protection. Lockups are due to nested locks in the unsolicited abort
path. The unsolicited abort path calls the wrong abort processing
routine. There was also duplicate context release while aborts were still
active in the hardware.

Removed duplicate locks and added lock protection around list item
removal. Commonized lock handling around the abort processing routines.
Prevent context release while still in ABTS list.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 37 insertions, 13 deletions

diff --git a/drivers/scsi/lpfc/lpfc_nvmet.c b/drivers/scsi/lpfc/lpfc_nvmet.c
index 0d10dfc74018..4aadb3d5e718 100644
--- a/drivers/scsi/lpfc/lpfc_nvmet.c
+++ b/drivers/scsi/lpfc/lpfc_nvmet.c
@@ -1032,7 +1032,6 @@ lpfc_nvmet_xmt_fcp_abort(struct nvmet_fc_target_port *tgtport,
 	atomic_inc(&lpfc_nvmep->xmt_fcp_abort);
 
 	spin_lock_irqsave(&ctxp->ctxlock, flags);
-	ctxp->state = LPFC_NVMET_STE_ABORT;
 
 	/* Since iaab/iaar are NOT set, we need to check
 	 * if the firmware is in process of aborting IO
@@ -1044,13 +1043,14 @@ lpfc_nvmet_xmt_fcp_abort(struct nvmet_fc_target_port *tgtport,
 	ctxp->flag |= LPFC_NVMET_ABORT_OP;
 
 	if (ctxp->flag & LPFC_NVMET_DEFER_WQFULL) {
+		spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 		lpfc_nvmet_unsol_fcp_issue_abort(phba, ctxp, ctxp->sid,
 						 ctxp->oxid);
 		wq = ctxp->hdwq->nvme_wq;
-		spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 		lpfc_nvmet_wqfull_flush(phba, wq, ctxp);
 		return;
 	}
+	spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 
 	/* An state of LPFC_NVMET_STE_RCV means we have just received
 	 * the NVME command and have not started processing it.
@@ -1062,7 +1062,6 @@ lpfc_nvmet_xmt_fcp_abort(struct nvmet_fc_target_port *tgtport,
 	else
 		lpfc_nvmet_sol_fcp_issue_abort(phba, ctxp, ctxp->sid,
 					       ctxp->oxid);
-	spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 }
 
 static void
@@ -1076,14 +1075,18 @@ lpfc_nvmet_xmt_fcp_release(struct nvmet_fc_target_port *tgtport,
 	unsigned long flags;
 	bool aborting = false;
 
-	if (ctxp->state != LPFC_NVMET_STE_DONE &&
-	    ctxp->state != LPFC_NVMET_STE_ABORT) {
+	spin_lock_irqsave(&ctxp->ctxlock, flags);
+	if (ctxp->flag & LPFC_NVMET_XBUSY)
+		lpfc_printf_log(phba, KERN_INFO, LOG_NVME_IOERR,
+				"6027 NVMET release with XBUSY flag x%x"
+				" oxid x%x\n",
+				ctxp->flag, ctxp->oxid);
+	else if (ctxp->state != LPFC_NVMET_STE_DONE &&
+		 ctxp->state != LPFC_NVMET_STE_ABORT)
 		lpfc_printf_log(phba, KERN_ERR, LOG_NVME_IOERR,
 				"6413 NVMET release bad state %d %d oxid x%x\n",
 				ctxp->state, ctxp->entry_cnt, ctxp->oxid);
-	}
 
-	spin_lock_irqsave(&ctxp->ctxlock, flags);
 	if ((ctxp->flag & LPFC_NVMET_ABORT_OP) ||
 	    (ctxp->flag & LPFC_NVMET_XBUSY)) {
 		aborting = true;
@@ -1523,6 +1526,7 @@ lpfc_sli4_nvmet_xri_aborted(struct lpfc_hba *phba,
 		if (ctxp->ctxbuf->sglq->sli4_xritag != xri)
 			continue;
 
+		spin_lock(&ctxp->ctxlock);
 		/* Check if we already received a free context call
 		 * and we have completed processing an abort situation.
 		 */
@@ -1532,6 +1536,7 @@ lpfc_sli4_nvmet_xri_aborted(struct lpfc_hba *phba,
 			released = true;
 		}
 		ctxp->flag &= ~LPFC_NVMET_XBUSY;
+		spin_unlock(&ctxp->ctxlock);
 		spin_unlock(&phba->sli4_hba.abts_nvmet_buf_list_lock);
 
 		rrq_empty = list_empty(&phba->active_rrq_list);
@@ -1563,7 +1568,6 @@ lpfc_sli4_nvmet_xri_aborted(struct lpfc_hba *phba,
 int
 lpfc_nvmet_rcv_unsol_abort(struct lpfc_vport *vport,
 			   struct fc_frame_header *fc_hdr)
-
 {
 #if (IS_ENABLED(CONFIG_NVME_TARGET_FC))
 	struct lpfc_hba *phba = vport->phba;
@@ -2696,15 +2700,17 @@ lpfc_nvmet_sol_fcp_abort_cmp(struct lpfc_hba *phba, struct lpfc_iocbq *cmdwqe,
 	if (ctxp->flag & LPFC_NVMET_ABORT_OP)
 		atomic_inc(&tgtp->xmt_fcp_abort_cmpl);
 
+	spin_lock_irqsave(&ctxp->ctxlock, flags);
 	ctxp->state = LPFC_NVMET_STE_DONE;
 
 	/* Check if we already received a free context call
 	 * and we have completed processing an abort situation.
 	 */
-	spin_lock_irqsave(&ctxp->ctxlock, flags);
 	if ((ctxp->flag & LPFC_NVMET_CTX_RLS) &&
 	    !(ctxp->flag & LPFC_NVMET_XBUSY)) {
+		spin_lock(&phba->sli4_hba.abts_nvmet_buf_list_lock);
 		list_del(&ctxp->list);
+		spin_unlock(&phba->sli4_hba.abts_nvmet_buf_list_lock);
 		released = true;
 	}
 	ctxp->flag &= ~LPFC_NVMET_ABORT_OP;
@@ -2770,6 +2776,7 @@ lpfc_nvmet_unsol_fcp_abort_cmp(struct lpfc_hba *phba, struct lpfc_iocbq *cmdwqe,
 	}
 
 	tgtp = (struct lpfc_nvmet_tgtport *)phba->targetport->private;
+	spin_lock_irqsave(&ctxp->ctxlock, flags);
 	if (ctxp->flag & LPFC_NVMET_ABORT_OP)
 		atomic_inc(&tgtp->xmt_fcp_abort_cmpl);
 
@@ -2784,10 +2791,11 @@ lpfc_nvmet_unsol_fcp_abort_cmp(struct lpfc_hba *phba, struct lpfc_iocbq *cmdwqe,
 	 * and we have completed processing an abort situation.
 	 */
 	ctxp->state = LPFC_NVMET_STE_DONE;
-	spin_lock_irqsave(&ctxp->ctxlock, flags);
 	if ((ctxp->flag & LPFC_NVMET_CTX_RLS) &&
 	    !(ctxp->flag & LPFC_NVMET_XBUSY)) {
+		spin_lock(&phba->sli4_hba.abts_nvmet_buf_list_lock);
 		list_del(&ctxp->list);
+		spin_unlock(&phba->sli4_hba.abts_nvmet_buf_list_lock);
 		released = true;
 	}
 	ctxp->flag &= ~LPFC_NVMET_ABORT_OP;
@@ -2993,12 +3001,15 @@ lpfc_nvmet_sol_fcp_issue_abort(struct lpfc_hba *phba,
 				(ndlp) ? ndlp->nlp_state : NLP_STE_MAX_STATE);
 
 		/* No failure to an ABTS request. */
+		spin_lock_irqsave(&ctxp->ctxlock, flags);
 		ctxp->flag &= ~LPFC_NVMET_ABORT_OP;
+		spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 		return 0;
 	}
 
 	/* Issue ABTS for this WQE based on iotag */
 	ctxp->abort_wqeq = lpfc_sli_get_iocbq(phba);
+	spin_lock_irqsave(&ctxp->ctxlock, flags);
 	if (!ctxp->abort_wqeq) {
 		atomic_inc(&tgtp->xmt_abort_rsp_error);
 		lpfc_printf_log(phba, KERN_ERR, LOG_NVME_ABTS,
@@ -3006,11 +3017,13 @@ lpfc_nvmet_sol_fcp_issue_abort(struct lpfc_hba *phba,
 				"xri: x%x\n", ctxp->oxid);
 		/* No failure to an ABTS request. */
 		ctxp->flag &= ~LPFC_NVMET_ABORT_OP;
+		spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 		return 0;
 	}
 	abts_wqeq = ctxp->abort_wqeq;
 	abts_wqe = &abts_wqeq->wqe;
 	ctxp->state = LPFC_NVMET_STE_ABORT;
+	spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 
 	/* Announce entry to new IO submit field. */
 	lpfc_printf_log(phba, KERN_INFO, LOG_NVME_ABTS,
@@ -3031,7 +3044,9 @@ lpfc_nvmet_sol_fcp_issue_abort(struct lpfc_hba *phba,
 				"NVME Req now. hba_flag x%x oxid x%x\n",
 				phba->hba_flag, ctxp->oxid);
 		lpfc_sli_release_iocbq(phba, abts_wqeq);
+		spin_lock_irqsave(&ctxp->ctxlock, flags);
 		ctxp->flag &= ~LPFC_NVMET_ABORT_OP;
+		spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 		return 0;
 	}
 
@@ -3044,7 +3059,9 @@ lpfc_nvmet_sol_fcp_issue_abort(struct lpfc_hba *phba,
 				"still pending on oxid x%x\n",
 				ctxp->oxid);
 		lpfc_sli_release_iocbq(phba, abts_wqeq);
+		spin_lock_irqsave(&ctxp->ctxlock, flags);
 		ctxp->flag &= ~LPFC_NVMET_ABORT_OP;
+		spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 		return 0;
 	}
 
@@ -3099,7 +3116,9 @@ lpfc_nvmet_sol_fcp_issue_abort(struct lpfc_hba *phba,
 	}
 
 	atomic_inc(&tgtp->xmt_abort_rsp_error);
+	spin_lock_irqsave(&ctxp->ctxlock, flags);
 	ctxp->flag &= ~LPFC_NVMET_ABORT_OP;
+	spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 	lpfc_sli_release_iocbq(phba, abts_wqeq);
 	lpfc_printf_log(phba, KERN_ERR, LOG_NVME_ABTS,
 			"6166 Failed ABORT issue_wqe with status x%x "
@@ -3108,7 +3127,6 @@ lpfc_nvmet_sol_fcp_issue_abort(struct lpfc_hba *phba,
 	return 1;
 }
 
-
 static int
 lpfc_nvmet_unsol_fcp_issue_abort(struct lpfc_hba *phba,
 				 struct lpfc_nvmet_rcv_ctx *ctxp,
@@ -3117,6 +3135,7 @@ lpfc_nvmet_unsol_fcp_issue_abort(struct lpfc_hba *phba,
 	struct lpfc_nvmet_tgtport *tgtp;
 	struct lpfc_iocbq *abts_wqeq;
 	unsigned long flags;
+	bool released = false;
 	int rc;
 
 	tgtp = (struct lpfc_nvmet_tgtport *)phba->targetport->private;
@@ -3154,8 +3173,12 @@ lpfc_nvmet_unsol_fcp_issue_abort(struct lpfc_hba *phba,
 
 aerr:
 	spin_lock_irqsave(&ctxp->ctxlock, flags);
-	if (ctxp->flag & LPFC_NVMET_CTX_RLS)
+	if (ctxp->flag & LPFC_NVMET_CTX_RLS) {
+		spin_lock(&phba->sli4_hba.abts_nvmet_buf_list_lock);
 		list_del(&ctxp->list);
+		spin_unlock(&phba->sli4_hba.abts_nvmet_buf_list_lock);
+		released = true;
+	}
 	ctxp->flag &= ~(LPFC_NVMET_ABORT_OP | LPFC_NVMET_CTX_RLS);
 	spin_unlock_irqrestore(&ctxp->ctxlock, flags);
 
@@ -3163,7 +3186,8 @@ aerr:
 	lpfc_printf_log(phba, KERN_ERR, LOG_NVME_ABTS,
 			"6135 Failed to Issue ABTS for oxid x%x. Status x%x\n",
 			ctxp->oxid, rc);
-	lpfc_nvmet_ctxbuf_post(phba, ctxp->ctxbuf);
+	if (released)
+		lpfc_nvmet_ctxbuf_post(phba, ctxp->ctxbuf);
 	return 1;
 }