In namex, drop the refs dirlookup returns

51e3d118 · Silas Boyd-Wickizer · 91c171fc · 51e3d118
--- a/kernel/fs.cc
+++ b/kernel/fs.cc
@@ -746,13 +746,15 @@ static struct inode*
 namex(inode *cwd, const char *path, int nameiparent, char *name)
 {
  struct inode *ip, *next;
+  bool drop_ref;
  int r;
-  scoped_gc_epoch e;

+  scoped_gc_epoch e;
  if(*path == '/') 
    ip = igetnoref(ROOTDEV, ROOTINO);
  else
    ip = cwd;
+  drop_ref = false;

  while((r = skipelem(&path, name)) == 1){
    // XXX Doing this here requires some annoying reasoning about all
@@ -765,20 +767,23 @@ namex(inode *cwd, const char *path, int nameiparent, char *name)
    // the caller declare the variables?  Would it help for the caller
    // to pass in an abstract scope?
    mtreadavar("inode:%x.%x", ip->dev, ip->inum);
-    next = 0;
-    if(next == 0){
    if(ip->type == 0)
      panic("namex");
    if(ip->type != T_DIR)
      return 0;
    if(nameiparent && *path == '\0'){
      // Stop one level early.
+      if (!drop_ref)
        idup(ip);
      return ip;
    }
+
    if((next = dirlookup(ip, name)) == 0)
      return 0;
-    }
+    if (drop_ref)
+      iput(ip);
+
+    drop_ref = true;
    ip = next;
  }

@@ -792,6 +797,7 @@ namex(inode *cwd, const char *path, int nameiparent, char *name)
  // mtreadavar("inode:%x.%x", ip->dev, ip->inum);
  mtwriteavar("inode:%x.%x", ip->dev, ip->inum);

+  if (!drop_ref)
    idup(ip);
  return ip;
 }