[JFFS2] add write verify on dataflash.

[safe/jmp/linux-2.6] / fs / jffs2 / background.c

diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c
index 65119d7..8adebd3 100644 (file)
--- a/fs/jffs2/background.c
+++ b/fs/jffs2/background.c
@@ -1,20 +1,20 @@
 /*
  * JFFS2 -- Journalling Flash File System, Version 2.
  *
- * Copyright (C) 2001-2003 Red Hat, Inc.
+ * Copyright © 2001-2007 Red Hat, Inc.
  *
  * Created by David Woodhouse <dwmw2@infradead.org>
  *
  * For licensing information, see the file 'LICENCE' in this directory.
  *
- * $Id: background.c,v 1.54 2005/05/20 21:37:12 gleixner Exp $
- *
  */
 
 #include <linux/kernel.h>
 #include <linux/jffs2.h>
 #include <linux/mtd/mtd.h>
 #include <linux/completion.h>
+#include <linux/sched.h>
+#include <linux/freezer.h>
 #include "nodelist.h"
 
 
@@ -23,8 +23,8 @@ static int jffs2_garbage_collect_thread(void *);
 void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c)
 {
        spin_lock(&c->erase_completion_lock);
-        if (c->gc_task && jffs2_thread_should_wake(c))
-                send_sig(SIGHUP, c->gc_task, 1);
+       if (c->gc_task && jffs2_thread_should_wake(c))
+               send_sig(SIGHUP, c->gc_task, 1);
        spin_unlock(&c->erase_completion_lock);
 }
 
@@ -34,8 +34,7 @@ int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c)
        pid_t pid;
        int ret = 0;
 
-       if (c->gc_task)
-               BUG();
+       BUG_ON(c->gc_task);
 
        init_completion(&c->gc_thread_start);
        init_completion(&c->gc_thread_exit);
@@ -50,7 +49,7 @@ int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c)
                D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid));
                wait_for_completion(&c->gc_thread_start);
        }
- 
+
        return ret;
 }
 
@@ -82,9 +81,10 @@ static int jffs2_garbage_collect_thread(void *_c)
 
        set_user_nice(current, 10);
 
+       set_freezable();
        for (;;) {
                allow_signal(SIGHUP);
-
+       again:
                if (!jffs2_thread_should_wake(c)) {
                        set_current_state (TASK_INTERRUPTIBLE);
                        D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n"));
@@ -95,17 +95,23 @@ static int jffs2_garbage_collect_thread(void *_c)
                        schedule();
                }
 
-               if (try_to_freeze(0))
-                       continue;
+               /* This thread is purely an optimisation. But if it runs when
+                  other things could be running, it actually makes things a
+                  lot worse. Use yield() and put it at the back of the runqueue
+                  every time. Especially during boot, pulling an inode in
+                  with read_inode() is much preferable to having the GC thread
+                  get there first. */
+               yield();
 
-               cond_resched();
-
-               /* Put_super will send a SIGKILL and then wait on the sem. 
+               /* Put_super will send a SIGKILL and then wait on the sem.
                 */
-               while (signal_pending(current)) {
+               while (signal_pending(current) || freezing(current)) {
                        siginfo_t info;
                        unsigned long signr;
 
+                       if (try_to_freeze())
+                               goto again;
+
                        signr = dequeue_signal_lock(current, &current->blocked, &info);
 
                        switch(signr) {