From d98ddadd79ae45dec44f191986bf59136dd15e88 Mon Sep 17 00:00:00 2001
From: Frans Kaashoek <kaashoek@mit.edu>
Date: Tue, 20 Aug 2019 12:46:56 -0400
Subject: [PATCH] Also release buffer on failed copyout

---
 kernel/fs.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/fs.c b/kernel/fs.c
index da9bcca..5505408 100644
--- a/kernel/fs.c
+++ b/kernel/fs.c
@@ -470,8 +470,10 @@ readi(struct inode *ip, int user_dst, uint64 dst, uint off, uint n)
   for(tot=0; tot<n; tot+=m, off+=m, dst+=m){
     bp = bread(ip->dev, bmap(ip, off/BSIZE));
     m = min(n - tot, BSIZE - off%BSIZE);
-    if(either_copyout(user_dst, dst, bp->data + (off % BSIZE), m) == -1)
+    if(either_copyout(user_dst, dst, bp->data + (off % BSIZE), m) == -1) {
+      brelse(bp);
       break;
+    }
     brelse(bp);
   }
   return n;