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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/jffs2/background.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'fs/jffs2/background.c')
-rw-r--r--fs/jffs2/background.c140
1 files changed, 140 insertions, 0 deletions
diff --git a/fs/jffs2/background.c b/fs/jffs2/background.c
new file mode 100644
index 000000000000..1be6de27dd81
--- /dev/null
+++ b/fs/jffs2/background.c
@@ -0,0 +1,140 @@
1/*
2 * JFFS2 -- Journalling Flash File System, Version 2.
3 *
4 * Copyright (C) 2001-2003 Red Hat, Inc.
5 *
6 * Created by David Woodhouse <dwmw2@infradead.org>
7 *
8 * For licensing information, see the file 'LICENCE' in this directory.
9 *
10 * $Id: background.c,v 1.50 2004/11/16 20:36:10 dwmw2 Exp $
11 *
12 */
13
14#include <linux/kernel.h>
15#include <linux/jffs2.h>
16#include <linux/mtd/mtd.h>
17#include <linux/completion.h>
18#include "nodelist.h"
19
20
21static int jffs2_garbage_collect_thread(void *);
22
23void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c)
24{
25 spin_lock(&c->erase_completion_lock);
26 if (c->gc_task && jffs2_thread_should_wake(c))
27 send_sig(SIGHUP, c->gc_task, 1);
28 spin_unlock(&c->erase_completion_lock);
29}
30
31/* This must only ever be called when no GC thread is currently running */
32int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c)
33{
34 pid_t pid;
35 int ret = 0;
36
37 if (c->gc_task)
38 BUG();
39
40 init_MUTEX_LOCKED(&c->gc_thread_start);
41 init_completion(&c->gc_thread_exit);
42
43 pid = kernel_thread(jffs2_garbage_collect_thread, c, CLONE_FS|CLONE_FILES);
44 if (pid < 0) {
45 printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %d\n", -pid);
46 complete(&c->gc_thread_exit);
47 ret = pid;
48 } else {
49 /* Wait for it... */
50 D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid));
51 down(&c->gc_thread_start);
52 }
53
54 return ret;
55}
56
57void jffs2_stop_garbage_collect_thread(struct jffs2_sb_info *c)
58{
59 spin_lock(&c->erase_completion_lock);
60 if (c->gc_task) {
61 D1(printk(KERN_DEBUG "jffs2: Killing GC task %d\n", c->gc_task->pid));
62 send_sig(SIGKILL, c->gc_task, 1);
63 }
64 spin_unlock(&c->erase_completion_lock);
65 wait_for_completion(&c->gc_thread_exit);
66}
67
68static int jffs2_garbage_collect_thread(void *_c)
69{
70 struct jffs2_sb_info *c = _c;
71
72 daemonize("jffs2_gcd_mtd%d", c->mtd->index);
73 allow_signal(SIGKILL);
74 allow_signal(SIGSTOP);
75 allow_signal(SIGCONT);
76
77 c->gc_task = current;
78 up(&c->gc_thread_start);
79
80 set_user_nice(current, 10);
81
82 for (;;) {
83 allow_signal(SIGHUP);
84
85 if (!jffs2_thread_should_wake(c)) {
86 set_current_state (TASK_INTERRUPTIBLE);
87 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n"));
88 /* Yes, there's a race here; we checked jffs2_thread_should_wake()
89 before setting current->state to TASK_INTERRUPTIBLE. But it doesn't
90 matter - We don't care if we miss a wakeup, because the GC thread
91 is only an optimisation anyway. */
92 schedule();
93 }
94
95 if (try_to_freeze(0))
96 continue;
97
98 cond_resched();
99
100 /* Put_super will send a SIGKILL and then wait on the sem.
101 */
102 while (signal_pending(current)) {
103 siginfo_t info;
104 unsigned long signr;
105
106 signr = dequeue_signal_lock(current, &current->blocked, &info);
107
108 switch(signr) {
109 case SIGSTOP:
110 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGSTOP received.\n"));
111 set_current_state(TASK_STOPPED);
112 schedule();
113 break;
114
115 case SIGKILL:
116 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGKILL received.\n"));
117 goto die;
118
119 case SIGHUP:
120 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGHUP received.\n"));
121 break;
122 default:
123 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): signal %ld received\n", signr));
124 }
125 }
126 /* We don't want SIGHUP to interrupt us. STOP and KILL are OK though. */
127 disallow_signal(SIGHUP);
128
129 D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): pass\n"));
130 if (jffs2_garbage_collect_pass(c) == -ENOSPC) {
131 printk(KERN_NOTICE "No space for garbage collection. Aborting GC thread\n");
132 goto die;
133 }
134 }
135 die:
136 spin_lock(&c->erase_completion_lock);
137 c->gc_task = NULL;
138 spin_unlock(&c->erase_completion_lock);
139 complete_and_exit(&c->gc_thread_exit, 0);
140}