avoid deadlock by calling begin_trans() before locking any inodes

1 files changed, 3 insertions, 4 deletions

diff --git a/fs.c b/fs.c
index a76788b..fe9ce48 100644
--- a/fs.c
+++ b/fs.c
@@ -43,13 +43,13 @@ bzero(int dev, int bno)
   
   bp = bread(dev, bno);
   memset(bp->data, 0, BSIZE);
-  bwrite(bp);
+  log_write(bp);
   brelse(bp);
 }
 
 // Blocks. 
 
-// Allocate a disk block.
+// Allocate a zeroed disk block.
 static uint
 balloc(uint dev)
 {
@@ -67,6 +67,7 @@ balloc(uint dev)
         bp->data[bi/8] |= m;  // Mark block in use on disk.
         log_write(bp);
         brelse(bp);
+        bzero(dev, b + bi);
         return b + bi;
       }
     }
@@ -83,8 +84,6 @@ bfree(int dev, uint b)
   struct superblock sb;
   int bi, m;
 
-  bzero(dev, b);
-
   readsb(dev, &sb);
   bp = bread(dev, BBLOCK(b, sb.ninodes));
   bi = b % BPB;