2 * JFFS2 -- Journalling Flash File System, Version 2.
4 * Copyright (C) 2001-2003 Red Hat, Inc.
6 * Created by David Woodhouse <dwmw2@redhat.com>
8 * For licensing information, see the file 'LICENCE' in this directory.
10 * $Id: background.c,v 1.49 2004/07/13 08:56:40 dwmw2 Exp $
14 #include <linux/kernel.h>
15 #include <linux/jffs2.h>
16 #include <linux/mtd/mtd.h>
17 #include <linux/completion.h>
18 #include <linux/suspend.h>
22 static int jffs2_garbage_collect_thread(void *);
24 void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c)
26 spin_lock(&c->erase_completion_lock);
27 if (c->gc_task && jffs2_thread_should_wake(c))
28 send_sig(SIGHUP, c->gc_task, 1);
29 spin_unlock(&c->erase_completion_lock);
32 /* This must only ever be called when no GC thread is currently running */
33 int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c)
41 init_MUTEX_LOCKED(&c->gc_thread_start);
42 init_completion(&c->gc_thread_exit);
44 pid = kernel_thread(jffs2_garbage_collect_thread, c, CLONE_FS|CLONE_FILES);
46 printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %d\n", -pid);
47 complete(&c->gc_thread_exit);
51 D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid));
52 down(&c->gc_thread_start);
58 void jffs2_stop_garbage_collect_thread(struct jffs2_sb_info *c)
60 spin_lock(&c->erase_completion_lock);
62 D1(printk(KERN_DEBUG "jffs2: Killing GC task %d\n", c->gc_task->pid));
63 send_sig(SIGKILL, c->gc_task, 1);
65 spin_unlock(&c->erase_completion_lock);
66 wait_for_completion(&c->gc_thread_exit);
69 static int jffs2_garbage_collect_thread(void *_c)
71 struct jffs2_sb_info *c = _c;
73 daemonize("jffs2_gcd_mtd%d", c->mtd->index);
74 allow_signal(SIGKILL);
75 allow_signal(SIGSTOP);
76 allow_signal(SIGCONT);
79 up(&c->gc_thread_start);
81 set_user_nice(current, 10);
86 if (!jffs2_thread_should_wake(c)) {
87 set_current_state (TASK_INTERRUPTIBLE);
88 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n"));
89 /* Yes, there's a race here; we checked jffs2_thread_should_wake()
90 before setting current->state to TASK_INTERRUPTIBLE. But it doesn't
91 matter - We don't care if we miss a wakeup, because the GC thread
92 is only an optimisation anyway. */
96 if (current->flags & PF_FREEZE) {
98 /* refrigerator() should recalc sigpending for us
99 but doesn't. No matter - allow_signal() will. */
105 /* Put_super will send a SIGKILL and then wait on the sem.
107 while (signal_pending(current)) {
111 signr = dequeue_signal_lock(current, ¤t->blocked, &info);
115 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGSTOP received.\n"));
116 set_current_state(TASK_STOPPED);
121 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGKILL received.\n"));
125 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGHUP received.\n"));
128 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): signal %ld received\n", signr));
131 /* We don't want SIGHUP to interrupt us. STOP and KILL are OK though. */
132 disallow_signal(SIGHUP);
134 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): pass\n"));
135 if (jffs2_garbage_collect_pass(c) == -ENOSPC) {
136 printk(KERN_NOTICE "No space for garbage collection. Aborting GC thread\n");
141 spin_lock(&c->erase_completion_lock);
143 spin_unlock(&c->erase_completion_lock);
144 complete_and_exit(&c->gc_thread_exit, 0);