scsi: lpfc: Fix removal of SCSI transport device get and put on dev structure

The lpfc driver is calling get_device and put_device on scsi_fc_transport
device structure. When this code was removed, the driver triggered an oops
in "scsi_is_host_dev" when the first SCSI target was unregistered from the
transport.

The reason the calls were necessary is that the driver is calling
scsi_remove_host too early, before the target rports are unregistered and
the scsi devices disconnected from the scsi_host.  The fc_host was torn
down during fc_remove_host.

Fix by moving the lpfc_pci_remove_one_s3/s4 calls to scsi_remove_host to
after the nodes are cleaned up.  Remove the get_device and put_device calls
and the supporting code.

Link: https://lore.kernel.org/r/20201115192646.12977-4-james.smart@broadcom.comCo-developed-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <james.smart@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/lpfc/lpfc_els.c

@@ -1601,7 +1601,6 @@ lpfc_plogi_confirm_nport(struct lpfc_hba *phba, uint32_t *prsp,
 	u32 keep_nlp_fc4_type = 0;
 	struct lpfc_nvme_rport *keep_nrport = NULL;
 	int  put_node;
-	int  put_rport;
 	unsigned long *active_rrqs_xri_bitmap = NULL;
 
 	/* Fabric nodes can have the same WWPN so we don't bother searching
@@ -1804,13 +1803,10 @@ lpfc_plogi_confirm_nport(struct lpfc_hba *phba, uint32_t *prsp,
 		if (rport) {
 			rdata = rport->dd_data;
 			put_node = rdata->pnode != NULL;
-			put_rport = ndlp->rport != NULL;
 			rdata->pnode = NULL;
 			ndlp->rport = NULL;
 			if (put_node)
 				lpfc_nlp_put(ndlp);
-			if (put_rport)
-				put_device(&rport->dev);
 		}
 	}
 

drivers/scsi/lpfc/lpfc_hbadisc.c

@@ -117,7 +117,6 @@ lpfc_dev_loss_tmo_callbk(struct fc_rport *rport)
 	struct lpfc_hba   *phba;
 	struct lpfc_work_evt *evtp;
 	int  put_node;
-	int  put_rport;
 	unsigned long iflags;
 
 	rdata = rport->dd_data;
@@ -142,13 +141,10 @@ lpfc_dev_loss_tmo_callbk(struct fc_rport *rport)
 	 */
 	if (vport->load_flag & FC_UNLOADING) {
 		put_node = rdata->pnode != NULL;
-		put_rport = ndlp->rport != NULL;
 		rdata->pnode = NULL;
 		ndlp->rport = NULL;
 		if (put_node)
 			lpfc_nlp_put(ndlp);
-		if (put_rport)
-			put_device(&rport->dev);
 		return;
 	}
 
@@ -263,7 +259,6 @@ lpfc_dev_loss_tmo_handler(struct lpfc_nodelist *ndlp)
 		ndlp->rport = NULL;
 		if (put_node)
 			lpfc_nlp_put(ndlp);
-		put_device(&rport->dev);
 
 		return fcf_inuse;
 	}
@@ -284,7 +279,6 @@ lpfc_dev_loss_tmo_handler(struct lpfc_nodelist *ndlp)
 	ndlp->rport = NULL;
 	if (put_node)
 		lpfc_nlp_put(ndlp);
-	put_device(&rport->dev);
 
 	if (ndlp->nlp_type & NLP_FABRIC)
 		return fcf_inuse;
@@ -4190,8 +4184,6 @@ lpfc_register_remote_port(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
 				lpfc_nlp_put(ndlp);
 			rdata->pnode = NULL;
 		}
-		/* drop reference for earlier registeration */
-		put_device(&rport->dev);
 	}
 
 	lpfc_debugfs_disc_trc(vport, LPFC_DISC_TRC_RPORT,
@@ -4203,7 +4195,7 @@ lpfc_register_remote_port(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
 		return;
 
 	ndlp->rport = rport = fc_remote_port_add(shost, 0, &rport_ids);
-	if (!rport || !get_device(&rport->dev)) {
+	if (!rport) {
 		dev_printk(KERN_WARNING, &phba->pcidev->dev,
 			   "Warning: fc_remote_port_add failed\n");
 		return;
@@ -4244,6 +4236,7 @@ lpfc_register_remote_port(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
 	    (rport->scsi_target_id < LPFC_MAX_TARGET)) {
 		ndlp->nlp_sid = rport->scsi_target_id;
 	}
+
 	return;
 }
 
@@ -5217,7 +5210,6 @@ lpfc_nlp_remove(struct lpfc_vport *vport, struct lpfc_nodelist *ndlp)
 		rdata = rport->dd_data;
 		rdata->pnode = NULL;
 		ndlp->rport = NULL;
-		put_device(&rport->dev);
 	}
 }
 

drivers/scsi/lpfc/lpfc_init.c

@@ -12499,12 +12499,15 @@ lpfc_pci_remove_one_s3(struct pci_dev *pdev)
 		}
 	lpfc_destroy_vport_work_array(phba, vports);
 
-	/* Remove FC host and then SCSI host with the physical port */
+	/* Remove FC host with the physical port */
 	fc_remove_host(shost);
-	scsi_remove_host(shost);
 
+	/* Clean up all nodes, mailboxes and IOs. */
 	lpfc_cleanup(vport);
 
+	/* Remove the shost now that the devices connections are lost. */
+	scsi_remove_host(shost);
+
 	/*
 	 * Bring down the SLI Layer. This step disable all interrupts,
 	 * clears the rings, discards all mailbox commands, and resets
@@ -13342,7 +13345,6 @@ lpfc_pci_remove_one_s4(struct pci_dev *pdev)
 	vport->load_flag |= FC_UNLOADING;
 	spin_unlock_irq(&phba->hbalock);
 
-	/* Free the HBA sysfs attributes */
 	lpfc_free_sysfs_attr(vport);
 
 	/* Release all the vports against this physical port */
@@ -13355,9 +13357,8 @@ lpfc_pci_remove_one_s4(struct pci_dev *pdev)
 		}
 	lpfc_destroy_vport_work_array(phba, vports);
 
-	/* Remove FC host and then SCSI host with the physical port */
+	/* Remove FC host with the physical port */
 	fc_remove_host(shost);
-	scsi_remove_host(shost);
 
 	/* Perform ndlp cleanup on the physical port.  The nvme and nvmet
 	 * localports are destroyed after to cleanup all transport memory.
@@ -13370,6 +13371,9 @@ lpfc_pci_remove_one_s4(struct pci_dev *pdev)
 	if (phba->cfg_xri_rebalancing)
 		lpfc_destroy_multixri_pools(phba);
 
+	/* Remove the shost now that the devices connections are lost. */
+	scsi_remove_host(shost);
+
 	/*
 	 * Bring down the SLI Layer. This step disables all interrupts,
 	 * clears the rings, discards all mailbox commands, and resets

drivers/scsi/lpfc/lpfc_vport.c

@@ -664,9 +664,8 @@ lpfc_vport_delete(struct fc_vport *fc_vport)
 		ns_ndlp_referenced = true;
 	}
 
-	/* Remove FC host and then SCSI host with the vport */
+	/* Remove FC host to break driver binding. */
 	fc_remove_host(shost);
-	scsi_remove_host(shost);
 
 	ndlp = lpfc_findnode_did(phba->pport, Fabric_DID);
 
@@ -747,6 +746,9 @@ lpfc_vport_delete(struct fc_vport *fc_vport)
 	}
 
 	lpfc_cleanup(vport);
+
+	/* Remove scsi host now.  The nodes are cleaned up. */
+	scsi_remove_host(shost);
 	lpfc_sli_host_down(vport);
 
 	lpfc_stop_vport_timers(vport);