[SCSI] lpfc 8.3.42: Fixed race condition between BSG I/O dispatch and timeout handling

Signed-off-by: James Smart <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/lpfc/lpfc_bsg.c

···
 	}
 	spin_unlock_irqrestore(&phba->ct_ev_lock, flags);
 
+	/* Close the timeout handler abort window */
+	spin_lock_irqsave(&phba->hbalock, flags);
+	cmdiocbq->iocb_aux_flag &= ~LPFC_IO_CMD_OUTSTANDING;
+	spin_unlock_irqrestore(&phba->hbalock, flags);
+
 	iocb = &dd_data->context_un.iocb;
 	ndlp = iocb->ndlp;
 	rmp = iocb->rmp;
···
 	int request_nseg;
 	int reply_nseg;
 	struct bsg_job_data *dd_data;
+	unsigned long flags;
 	uint32_t creg_val;
 	int rc = 0;
 	int iocb_stat;
···
 	}
 
 	iocb_stat = lpfc_sli_issue_iocb(phba, LPFC_ELS_RING, cmdiocbq, 0);
-	if (iocb_stat == IOCB_SUCCESS)
+
+	if (iocb_stat == IOCB_SUCCESS) {
+		spin_lock_irqsave(&phba->hbalock, flags);
+		/* make sure the I/O had not been completed yet */
+		if (cmdiocbq->iocb_flag & LPFC_IO_LIBDFC) {
+			/* open up abort window to timeout handler */
+			cmdiocbq->iocb_aux_flag |= LPFC_IO_CMD_OUTSTANDING;
+		}
+		spin_unlock_irqrestore(&phba->hbalock, flags);
 		return 0; /* done for now */
-	else if (iocb_stat == IOCB_BUSY)
+	} else if (iocb_stat == IOCB_BUSY) {
 		rc = -EAGAIN;
-	else
+	} else {
 		rc = -EIO;
+	}
 
 	/* iocb failed so cleanup */
+	job->dd_data = NULL;
 
 free_rmp:
 	lpfc_free_bsg_buffers(phba, rmp);
···
 	}
 	spin_unlock_irqrestore(&phba->ct_ev_lock, flags);
 
+	/* Close the timeout handler abort window */
+	spin_lock_irqsave(&phba->hbalock, flags);
+	cmdiocbq->iocb_aux_flag &= ~LPFC_IO_CMD_OUTSTANDING;
+	spin_unlock_irqrestore(&phba->hbalock, flags);
+
 	rsp = &rspiocbq->iocb;
 	pcmd = (struct lpfc_dmabuf *)cmdiocbq->context2;
 	prsp = (struct lpfc_dmabuf *)pcmd->list.next;
···
 	struct lpfc_iocbq *cmdiocbq;
 	uint16_t rpi = 0;
 	struct bsg_job_data *dd_data;
+	unsigned long flags;
 	uint32_t creg_val;
 	int rc = 0;
 
···
 
 	rc = lpfc_sli_issue_iocb(phba, LPFC_ELS_RING, cmdiocbq, 0);
 
-	if (rc == IOCB_SUCCESS)
+	if (rc == IOCB_SUCCESS) {
+		spin_lock_irqsave(&phba->hbalock, flags);
+		/* make sure the I/O had not been completed/released */
+		if (cmdiocbq->iocb_flag & LPFC_IO_LIBDFC) {
+			/* open up abort window to timeout handler */
+			cmdiocbq->iocb_aux_flag |= LPFC_IO_CMD_OUTSTANDING;
+		}
+		spin_unlock_irqrestore(&phba->hbalock, flags);
 		return 0; /* done for now */
-	else if (rc == IOCB_BUSY)
+	} else if (rc == IOCB_BUSY) {
 		rc = -EAGAIN;
-	else
+	} else {
 		rc = -EIO;
+	}
+
+	/* iocb failed so cleanup */
+	job->dd_data = NULL;
 
 linkdown_err:
-
 	cmdiocbq->context1 = ndlp;
 	lpfc_els_free_iocb(phba, cmdiocbq);
 
···
 	}
 	spin_unlock_irqrestore(&phba->ct_ev_lock, flags);
 
+	/* Close the timeout handler abort window */
+	spin_lock_irqsave(&phba->hbalock, flags);
+	cmdiocbq->iocb_aux_flag &= ~LPFC_IO_CMD_OUTSTANDING;
+	spin_unlock_irqrestore(&phba->hbalock, flags);
+
 	ndlp = dd_data->context_un.iocb.ndlp;
 	cmp = cmdiocbq->context2;
 	bmp = cmdiocbq->context3;
···
 	int rc = 0;
 	struct lpfc_nodelist *ndlp = NULL;
 	struct bsg_job_data *dd_data;
+	unsigned long flags;
 	uint32_t creg_val;
 
 	/* allocate our bsg tracking structure */
···
 
 	rc = lpfc_sli_issue_iocb(phba, LPFC_ELS_RING, ctiocb, 0);
 
-	if (rc == IOCB_SUCCESS)
+	if (rc == IOCB_SUCCESS) {
+		spin_lock_irqsave(&phba->hbalock, flags);
+		/* make sure the I/O had not been completed/released */
+		if (ctiocb->iocb_flag & LPFC_IO_LIBDFC) {
+			/* open up abort window to timeout handler */
+			ctiocb->iocb_aux_flag |= LPFC_IO_CMD_OUTSTANDING;
+		}
+		spin_unlock_irqrestore(&phba->hbalock, flags);
 		return 0; /* done for now */
+	}
+
+	/* iocb failed so cleanup */
+	job->dd_data = NULL;
 
 issue_ct_rsp_exit:
 	lpfc_sli_release_iocbq(phba, ctiocb);
···
 		 * remove it from the txq queue and call cancel iocbs.
 		 * Otherwise, call abort iotag
 		 */
-
 		cmdiocb = dd_data->context_un.iocb.cmdiocbq;
-		spin_lock_irq(&phba->hbalock);
+		spin_unlock_irqrestore(&phba->ct_ev_lock, flags);
+
+		spin_lock_irqsave(&phba->hbalock, flags);
+		/* make sure the I/O abort window is still open */
+		if (!(cmdiocb->iocb_aux_flag & LPFC_IO_CMD_OUTSTANDING)) {
+			spin_unlock_irqrestore(&phba->hbalock, flags);
+			return -EAGAIN;
+		}
 		list_for_each_entry_safe(check_iocb, next_iocb, &pring->txq,
 					 list) {
 			if (check_iocb == cmdiocb) {
···
 		}
 		if (list_empty(&completions))
 			lpfc_sli_issue_abort_iotag(phba, pring, cmdiocb);
-		spin_unlock_irq(&phba->hbalock);
-		spin_unlock_irqrestore(&phba->ct_ev_lock, flags);
+		spin_unlock_irqrestore(&phba->hbalock, flags);
 		if (!list_empty(&completions)) {
 			lpfc_sli_cancel_iocbs(phba, &completions,
 					      IOSTAT_LOCAL_REJECT,
···
 		 * remove it from the txq queue and call cancel iocbs.
 		 * Otherwise, call abort iotag.
 		 */
-
 		cmdiocb = dd_data->context_un.menlo.cmdiocbq;
-		spin_lock_irq(&phba->hbalock);
+		spin_unlock_irqrestore(&phba->ct_ev_lock, flags);
+
+		spin_lock_irqsave(&phba->hbalock, flags);
 		list_for_each_entry_safe(check_iocb, next_iocb, &pring->txq,
 					 list) {
 			if (check_iocb == cmdiocb) {
···
 		}
 		if (list_empty(&completions))
 			lpfc_sli_issue_abort_iotag(phba, pring, cmdiocb);
-		spin_unlock_irq(&phba->hbalock);
-		spin_unlock_irqrestore(&phba->ct_ev_lock, flags);
+		spin_unlock_irqrestore(&phba->hbalock, flags);
 		if (!list_empty(&completions)) {
 			lpfc_sli_cancel_iocbs(phba, &completions,
 					      IOSTAT_LOCAL_REJECT,

drivers/scsi/lpfc/lpfc_sli.h

···
 #define LPFC_FIP_ELS_ID_MASK	0xc000	/* ELS_ID range 0-3, non-shifted mask */
 #define LPFC_FIP_ELS_ID_SHIFT	14
 
-	uint8_t rsvd2;
+	uint8_t iocb_aux_flag;
+#define LPFC_IO_CMD_OUTSTANDING	0x01 /* timeout handler abort window */
 	uint32_t drvrTimeout;	/* driver timeout in seconds */
 	uint32_t fcp_wqidx;	/* index to FCP work queue */
 	struct lpfc_vport *vport;/* virtual port pointer */