scsi: lpfc: Fix debugfs root inode "lpfc" not getting deleted on driver unload.

jsmart-gh · martinkpetersen · commit 667a7662529b · 2017-05-16T21:23:13.000-04:00
When unloading and reloading the driver, the driver fails to recreate
the lpfc root inode in the debugfs tree.

The driver is incorrectly removing the lpfc root inode in
lpfc_debugfs_terminate in the first driver instance that unloads and
then sets the lpfc_debugfs_root global parameter to NULL.  When the
final driver instance unloads, the debugfs calls quietly ignore the
remove on a NULL pointer.  The bug is that the debugfs_remove call
returns void so the driver doesn't know to correctly set the global
parameter to NULL.

Base the debugfs_remove of the lpfc_debugfs_root parameter on
lpfc_debugfs_hba_count because this parameter tracks the fnX instance
tracked per driver instance.

Signed-off-by: Dick Kennedy &lt;dick.kennedy@broadcom.com&gt;
Signed-off-by: James Smart &lt;james.smart@broadcom.com&gt;
Reviewed-by: Hannes Reinecke &lt;hare@suse.com&gt;
Signed-off-by: Martin K. Petersen &lt;martin.petersen@oracle.com&gt;
diff --git a/drivers/scsi/lpfc/lpfc_debugfs.c b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -5866,8 +5866,10 @@ lpfc_debugfs_terminate(struct lpfc_vport *vport)
 			atomic_dec(&lpfc_debugfs_hba_count);
 		}
 
-		debugfs_remove(lpfc_debugfs_root); /* lpfc */
-		lpfc_debugfs_root = NULL;
+		if (atomic_read(&lpfc_debugfs_hba_count) == 0) {
+			debugfs_remove(lpfc_debugfs_root); /* lpfc */
+			lpfc_debugfs_root = NULL;
+		}
 	}
 #endif
 	return;

Original file line number	Diff line number	Diff line change
`@@ -5866,8 +5866,10 @@ lpfc_debugfs_terminate(struct lpfc_vport *vport)`
`5866`	`5866`	`atomic_dec(&lpfc_debugfs_hba_count);`
`5867`	`5867`	`}`
`5868`	`5868`
`5869`		`- debugfs_remove(lpfc_debugfs_root); /* lpfc */`
`5870`		`- lpfc_debugfs_root = NULL;`
	`5869`	`+ if (atomic_read(&lpfc_debugfs_hba_count) == 0) {`
	`5870`	`+ debugfs_remove(lpfc_debugfs_root); /* lpfc */`
	`5871`	`+ lpfc_debugfs_root = NULL;`
	`5872`	`+ }`
`5871`	`5873`	`}`
`5872`	`5874`	`#endif`
`5873`	`5875`	`return;`