From: Ben Pfaff <blp@cs.stanford.edu>
Date: Fri, 19 May 2006 02:45:13 +0000 (+0000)
Subject: Fix race in dir_reopen().
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ad4fa177fa9b3931c5460dc47cb8b62630c01705;p=pintos-anon

Fix race in dir_reopen().
Thanks to Godmar Back for pointing this out (twice).
---

diff --git a/solutions/p4.patch b/solutions/p4.patch
index 9e11e25..7ab0046 100644
--- a/solutions/p4.patch
+++ b/solutions/p4.patch
@@ -726,7 +726,7 @@ diff -u src/filesys/directory.c~ src/filesys/directory.c
    return dir != NULL;
  }
  
-@@ -61,22 +99,34 @@ dir_open_root (struct dir **dirp)
+@@ -61,22 +99,36 @@ dir_open_root (struct dir **dirp)
    return dir_open (inode_open (ROOT_DIR_SECTOR), dirp);
  }
  
@@ -734,7 +734,9 @@ diff -u src/filesys/directory.c~ src/filesys/directory.c
 +bool
 +dir_reopen (struct dir *dir)
 +{
++  lock_acquire (&dir->dir_lock);
 +  dir->open_cnt++;
++  lock_release (&dir->dir_lock);
 +  return true;
 +}
 +