Fix rox checking and make filesys_lock global

src/threads/synch.c

@@ -212,7 +212,6 @@ donate_priority (struct thread *donee) {
   ASSERT (intr_get_level () == INTR_OFF);
 
   struct thread *donor = thread_current ();
-  list_remove (&donor->donor_elem);
   list_push_back (&donee->donors_list, &donor->donor_elem);
   
   while (donee != NULL)
@@ -261,7 +260,6 @@ lock_acquire (struct lock *lock)
   ASSERT (!lock_held_by_current_thread (lock));
 
   struct thread *t = thread_current ();
-  ASSERT (t->waiting_lock == NULL);
 
   enum intr_level old_level = intr_disable ();
   if (lock->holder != NULL)
@@ -343,6 +341,7 @@ lock_release (struct lock *lock)
      released, transfer the remaining orphaned donors to its donor list. */
   if (max_donor != NULL)
     {
+      list_remove (&max_donor->donor_elem);
       while (!list_empty (&orphan_list))
         list_push_back (&max_donor->donors_list, list_pop_front (&orphan_list));
     }

src/threads/thread.c

@@ -373,9 +373,7 @@ thread_exit (void)
      and schedule another process.  That process will destroy us
      when it calls thread_schedule_tail(). */
   intr_disable ();
-  struct thread *t = thread_current ();
-  list_remove (&t->allelem);
-  list_remove (&t->donor_elem);
+  list_remove (&thread_current()->allelem);
   thread_current ()->status = THREAD_DYING;
   schedule ();
   NOT_REACHED ();
@@ -681,7 +679,6 @@ init_thread (struct thread *t, const char *name, int nice, int priority,
   t->base_priority
       = thread_mlfqs ? calculate_bsd_priority (recent_cpu, nice) : priority;
   list_init (&t->donors_list);
-  list_push_back (&t->donors_list, &t->donor_elem);
   t->waiting_lock = NULL;
 
   t->nice = nice;

src/userprog/process.c

@@ -82,14 +82,8 @@ process_execute (const char *cmd)
      of the process. */
   char *file_name = strtok_r (cmd_copy, " ", &data->cmd_saveptr);
 
-  /* NOTE: Currently, the file being executed is closed in load () and then
-          reopened here. Because load is an exported public function, this
-          might be necessary. */
-  lock_acquire (&filesys_lock);
   /* Validates that the current file to be executed is a valid file */
-  bool valid_file = filesys_open (file_name) != NULL;
-  lock_release (&filesys_lock);
-  if (!valid_file)
+  if (filesys_open (file_name) == NULL)
     return TID_ERROR;
 
   /* Create a new thread to execute the command, by initializing
@@ -127,15 +121,6 @@ start_process (void *proc_start_data)
   if_.gs = if_.fs = if_.es = if_.ds = if_.ss = SEL_UDSEG;
   if_.cs = SEL_UCSEG;
   if_.eflags = FLAG_IF | FLAG_MBS;
-  
-  lock_acquire (&filesys_lock);
-  
-  /* Prevent writing to the file being executed. */
-  struct file *exec_file = filesys_open (data->file_name);
-  thread_current ()->exec_file = exec_file;
-  file_deny_write (exec_file);
-  lock_release (&filesys_lock);
-
   success = load (data->file_name, &if_.eip, &if_.esp);
 
   /* If load failed, quit. */
@@ -157,6 +142,13 @@ start_process (void *proc_start_data)
       goto fail;
     }
 
+  /* NOTE: Currently, the file being executed is closed in load () and then 
+           reopened here. Because load is an exported public function, this
+           might be necessary. */
+  struct file *exec_file = filesys_open (data->file_name);
+  thread_current ()->exec_file = exec_file;
+  file_deny_write (exec_file);
+
   /* Start the user process by simulating a return from an
      interrupt, implemented by intr_exit (in
      threads/intr-stubs.S).  Because intr_exit takes all of its
@@ -325,13 +317,7 @@ process_exit (void)
   uint32_t *pd;
 
   printf ("%s: exit(%d)\n", cur->name, cur->exit_status);
-  if (cur->exec_file != NULL)
-    {
-      lock_acquire (&filesys_lock);
-      file_allow_write (cur->exec_file);
   file_close (cur->exec_file);
-      lock_release (&filesys_lock);
-    }
 
   /* Update process result. */
   if (cur->result != NULL)
@@ -491,7 +477,6 @@ load (const char *file_name, void (**eip) (void), void **esp)
   off_t file_ofs;
   bool success = false;
   int i;
-  lock_acquire (&filesys_lock);
 
   /* Allocate and activate page directory. */
   t->pagedir = pagedir_create ();
@@ -591,7 +576,6 @@ load (const char *file_name, void (**eip) (void), void **esp)
  done:
   /* We arrive here whether the load is successful or not. */
   file_close (file);
-  lock_release (&filesys_lock);
   return success;
 }