diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 5705c51..5e1f806 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -580,11 +580,11 @@ restart:
 						ret = err;
 				}
 				up_read(&sb->s_umount);
-			}
+			} else count_vm_event(NR_SB_LOCKED);
 			spin_lock(&sb_lock);
 			if (__put_super_and_need_restart(sb))
 				goto restart;
-		}
+		} else count_vm_event(NR_SB_EMPTY);
 		if (wbc->nr_to_write <= 0)
 			break;
 	}
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 75370ec..f9d19f0 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -37,6 +37,8 @@ enum vm_event_item { PGPGIN, PGPGOUT, PSWPIN, PSWPOUT,
 		FOR_ALL_ZONES(PGSCAN_DIRECT),
 		PGINODESTEAL, SLABS_SCANNED, KSWAPD_STEAL, KSWAPD_INODESTEAL,
 		PAGEOUTRUN, ALLOCSTALL, PGROTATED,
+		NR_SB_LOCKED,
+		NR_SB_EMPTY,
 		NR_VM_EVENT_ITEMS
 };
 
diff --git a/mm/vmstat.c b/mm/vmstat.c
index 8e185f1..611f9d6 100644
--- a/mm/vmstat.c
+++ b/mm/vmstat.c
@@ -735,6 +735,9 @@ static const char * const vmstat_text[] = {
 	"allocstall",
 
 	"pgrotated",
+
+	"sb_locked",
+	"sb_empty",
 #endif
 };