sys_unlink doesn't touch parent diretory references

8989a18b · Silas Boyd-Wickizer · 04f26a8d · 8989a18b
--- a/kernel/sysfile.cc
+++ b/kernel/sysfile.cc
@@ -168,23 +168,24 @@ sys_unlink(const char *path)
 {
  struct inode *ip, *dp;
  char name[DIRSIZ];
+  bool haveref = false;

  if(argcheckstr(path) < 0)
    return -1;
-  if((dp = nameiparent(myproc()->cwd, path, name)) == 0)
+  if((dp = __nameiparent(myproc()->cwd, path, name, &haveref)) == 0)
    return -1;
  if(dp->type != T_DIR)
    panic("sys_unlink");

  // Cannot unlink "." or "..".
  if(namecmp(name, ".") == 0 || namecmp(name, "..") == 0){
-    iput(dp);
+    iput(dp, haveref);
    return -1;
  }

 retry:
  if((ip = dirlookup(dp, name)) == 0){
-    iput(dp);
+    iput(dp, haveref);
    return -1;
  }
  ilock(ip, 1);
@@ -193,7 +194,7 @@ sys_unlink(const char *path)
    panic("unlink: nlink < 1");
  if(ip->type == T_DIR && !isdirempty(ip)){
    iunlockput(ip);
-    iput(dp);
+    iput(dp, haveref);
    return -1;
  }

@@ -210,8 +211,7 @@ sys_unlink(const char *path)
    iunlock(dp);
  }

-  //nc_invalidate(dp, name);
-  iput(dp);
+  iput(dp, haveref);

  ip->unlink();
  iupdate(ip);
@@ -276,7 +276,8 @@ create(inode *cwd, const char *path, short type, short major, short minor)

    if (!dp->valid()) {
      // XXX(sbw) we need to undo everything we just did
-      // (at least all the modifications to dp) and retry.
+      // (at least all the modifications to dp) and retry
+      // (or return an error).
      panic("create: race");
    }
  }