ocfs2 patch to track delayed orphan scan timer statistics

Patch to track delayed orphan scan timer statistics.

Modifies ocfs2_osb_dump to print the following:
  Orphan Scan=> Local: 10  Global: 21  Last Scan: 67 seconds ago

Signed-off-by: Srinivas Eeda <srinivas.eeda@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

fs/ocfs2/ocfs2.h

@@ -156,7 +156,9 @@ struct ocfs2_orphan_scan {
 	struct ocfs2_super 	*os_osb;
 	struct ocfs2_lock_res 	os_lockres;     /* lock to synchronize scans */
 	struct delayed_work 	os_orphan_scan_work;
-	u32  			os_seqno;       /* incremented on every scan */
+	struct timespec		os_scantime;  /* time this node ran the scan */
+	u32			os_count;      /* tracks node specific scans */
+	u32  			os_seqno;       /* tracks cluster wide scans */
 };
 
 struct ocfs2_dlm_debug {