/*
* 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 1.52 2005/05/19 16:18:08 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 <linux/kthread.h>
#include "nodelist.h"
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;
}
void jffs2_stop_garbage_collect_thread(struct jffs2_sb_info *c)
{
+ int wait = 0;
spin_lock(&c->erase_completion_lock);
if (c->gc_task) {
D1(printk(KERN_DEBUG "jffs2: Killing GC task %d\n", c->gc_task->pid));
send_sig(SIGKILL, c->gc_task, 1);
+ wait = 1;
}
spin_unlock(&c->erase_completion_lock);
- wait_for_completion(&c->gc_thread_exit);
+ if (wait)
+ wait_for_completion(&c->gc_thread_exit);
}
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);
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(0))
- continue;
-
- 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, ¤t->blocked, &info);
switch(signr) {