sh: convert /proc/cpu/aligmnent, /proc/cpu/kernel_alignment to seq_file

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

diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c
index 7b77a95..3ff50da 100644 (file)
--- a/fs/jffs2/background.c
+++ b/fs/jffs2/background.c
@@ -1,14 +1,12 @@
 /*
  * 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>
@@ -16,6 +14,8 @@
 #include <linux/mtd/mtd.h>
 #include <linux/completion.h>
 #include <linux/sched.h>
+#include <linux/freezer.h>
+#include <linux/kthread.h>
 #include "nodelist.h"
 
 
@@ -24,32 +24,32 @@ 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);
 }
 
 /* This must only ever be called when no GC thread is currently running */
 int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c)
 {
-       pid_t pid;
+       struct task_struct *tsk;
        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);
 
-       pid = kernel_thread(jffs2_garbage_collect_thread, c, CLONE_FS|CLONE_FILES);
-       if (pid < 0) {
-               printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %d\n", -pid);
+       tsk = kthread_run(jffs2_garbage_collect_thread, c, "jffs2_gcd_mtd%d", c->mtd->index);
+       if (IS_ERR(tsk)) {
+               printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %ld\n", -PTR_ERR(tsk));
                complete(&c->gc_thread_exit);
-               ret = pid;
+               ret = PTR_ERR(tsk);
        } else {
                /* Wait for it... */
-               D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid));
+               D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", tsk->pid));
                wait_for_completion(&c->gc_thread_start);
+               ret = tsk->pid;
        }
 
        return ret;
@@ -73,7 +73,6 @@ static int jffs2_garbage_collect_thread(void *_c)
 {
        struct jffs2_sb_info *c = _c;
 
-       daemonize("jffs2_gcd_mtd%d", c->mtd->index);
        allow_signal(SIGKILL);
        allow_signal(SIGSTOP);
        allow_signal(SIGCONT);
@@ -83,30 +82,46 @@ static int jffs2_garbage_collect_thread(void *_c)
 
        set_user_nice(current, 10);
 
+       set_freezable();
        for (;;) {
                allow_signal(SIGHUP);
-
+       again:
+               spin_lock(&c->erase_completion_lock);
                if (!jffs2_thread_should_wake(c)) {
                        set_current_state (TASK_INTERRUPTIBLE);
+                       spin_unlock(&c->erase_completion_lock);
                        D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n"));
-                       /* Yes, there's a race here; we checked jffs2_thread_should_wake()
-                          before setting current->state to TASK_INTERRUPTIBLE. But it doesn't
-                          matter - We don't care if we miss a wakeup, because the GC thread
-                          is only an optimisation anyway. */
                        schedule();
+               } else
+                       spin_unlock(&c->erase_completion_lock);
+                       
+
+               /* Problem - immediately after bootup, the GCD spends a lot
+                * of time in places like jffs2_kill_fragtree(); so much so
+                * that userspace processes (like gdm and X) are starved
+                * despite plenty of cond_resched()s and renicing.  Yield()
+                * doesn't help, either (presumably because userspace and GCD
+                * are generally competing for a higher latency resource -
+                * disk).
+                * This forces the GCD to slow the hell down.   Pulling an
+                * inode in with read_inode() is much preferable to having
+                * the GC thread get there first. */
+               schedule_timeout_interruptible(msecs_to_jiffies(50));
+
+               if (kthread_should_stop()) {
+                       D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread():  kthread_stop() called.\n"));
+                       goto die;
                }
 
-               if (try_to_freeze())
-                       continue;
-
-               cond_resched();
-
                /* 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) {