1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/buf.h b/kernel/buf.h
index ae9d264..4a3a39d 100644
--- a/kernel/buf.h
+++ b/kernel/buf.h
@@ -1,5 +1,6 @@
 struct buf {
   int valid;   // has data been read from disk?
+  int disk;    // does disk "own" buf?
   uint dev;
   uint blockno;
   struct sleeplock lock;