Revert "Introduce and use sleeplocks instead of BUSY flags"

My changes have a race with re-used bufs and the code doesn't seem to get shorter
Keep the changes that fixed ip->off race

This reverts commit 3a5fa7ed9020eaf8ab843a16d26db7393b2ec072.

Conflicts:

	defs.h
	file.c
	file.h

1 files changed, 3 insertions, 4 deletions

diff --git a/file.h b/file.h
index 2b4a2cb..d123696 100644
--- a/file.h
+++ b/file.h
@@ -15,9 +15,7 @@ struct inode {
   uint dev;           // Device number
   uint inum;          // Inode number
   int ref;            // Reference count
-  int flags;          // I_VALID
-  struct spinlock lock;
-  struct sleeplock sleeplock;
+  int flags;          // I_BUSY, I_VALID
 
   short type;         // copy of disk inode
   short major;
@@ -27,7 +25,8 @@ struct inode {
   uint addrs[NDIRECT+1];
 };
 
-#define I_VALID 0x1
+#define I_BUSY 0x1
+#define I_VALID 0x2
 
 // device implementations