From f12551b5996ae6121d33afc94002ce6f7c64dcfd Mon Sep 17 00:00:00 2001
From: rsc <rsc>
Date: Sun, 31 May 2009 01:34:46 +0000
Subject: [PATCH] inode reuse bug.

Suppose an inode has been used and freed.
It is left marked I_VALID (the bug).
Now ialloc comes along and reuses the
inode.  It writes the new inode type to disk
and returns iget(dev, inum) to get the
cache entry.  Iget sees that the inode is valid
and doesn't bother refreshing from disk.
Now when the caller iupdates, it will write
out a zero type and the file or directory has
disappeared.
---
 fs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs.c b/fs.c
index 49a736d..abd7c0b 100644
--- a/fs.c
+++ b/fs.c
@@ -227,7 +227,7 @@ iunlock(struct inode *ip)
     panic("iunlock");
 
   acquire(&icache.lock);
-  ip->flags &= ~I_BUSY;
+  ip->flags = 0;
   wakeup(ip);
   release(&icache.lock);
 }