diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c
index 91b30a814ed9..b807db892bd9 100644
--- a/sys/kern/vfs_default.c
+++ b/sys/kern/vfs_default.c
@@ -646,8 +646,17 @@ loop2:
 		if ((bp->b_vflags & BV_SCANNED) != 0)
 			continue;
 		bp->b_vflags |= BV_SCANNED;
-		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL))
-			continue;
+		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
+			if (ap->a_waitfor != MNT_WAIT)
+				continue;
+			if (BUF_LOCK(bp,
+			    LK_EXCLUSIVE | LK_INTERLOCK | LK_SLEEPFAIL,
+			    BO_MTX(bo)) != 0) {
+				BO_LOCK(bo);
+				goto loop1;
+			}
+			BO_LOCK(bo);
+		}
 		BO_UNLOCK(bo);
 		KASSERT(bp->b_bufobj == bo,
 		    ("bp %p wrong b_bufobj %p should be %p",