1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
/*
* JFFS2 -- Journalling Flash File System, Version 2.
*
* Copyright (C) 2001 Red Hat, Inc.
*
* Created by David Woodhouse <dwmw2@cambridge.redhat.com>
*
* The original JFFS, from which the design for JFFS2 was derived,
* was designed and implemented by Axis Communications AB.
*
* The contents of this file are subject to the Red Hat eCos Public
* License Version 1.1 (the "Licence"); you may not use this file
* except in compliance with the Licence. You may obtain a copy of
* the Licence at http://www.redhat.com/
*
* Software distributed under the Licence is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.
* See the Licence for the specific language governing rights and
* limitations under the Licence.
*
* The Original Code is JFFS2 - Journalling Flash File System, version 2
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU General Public License version 2 (the "GPL"), in
* which case the provisions of the GPL are applicable instead of the
* above. If you wish to allow the use of your version of this file
* only under the terms of the GPL and not to allow others to use your
* version of this file under the RHEPL, indicate your decision by
* deleting the provisions above and replace them with the notice and
* other provisions required by the GPL. If you do not delete the
* provisions above, a recipient may use your version of this file
* under either the RHEPL or the GPL.
*
* $Id: background.c,v 1.16 2001/10/08 09:22:38 dwmw2 Exp $
*
*/
#define __KERNEL_SYSCALLS__
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/unistd.h>
#include <linux/jffs2.h>
#include <linux/mtd/mtd.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include "nodelist.h"
static int jffs2_garbage_collect_thread(void *);
static int thread_should_wake(struct jffs2_sb_info *c);
void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c)
{
spin_lock_bh(&c->erase_completion_lock);
if (c->gc_task && thread_should_wake(c))
send_sig(SIGHUP, c->gc_task, 1);
spin_unlock_bh(&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;
int ret = 0;
if (c->gc_task)
BUG();
init_MUTEX_LOCKED(&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);
complete(&c->gc_thread_exit);
ret = pid;
} else {
/* Wait for it... */
D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid));
down(&c->gc_thread_start);
}
return ret;
}
void jffs2_stop_garbage_collect_thread(struct jffs2_sb_info *c)
{
spin_lock_bh(&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);
}
spin_unlock_bh(&c->erase_completion_lock);
wait_for_completion(&c->gc_thread_exit);
}
static int jffs2_garbage_collect_thread(void *_c)
{
struct jffs2_sb_info *c = _c;
daemonize();
current->tty = NULL;
c->gc_task = current;
up(&c->gc_thread_start);
sprintf(current->comm, "jffs2_gcd_mtd%d", c->mtd->index);
/* FIXME in the 2.2 backport */
current->nice = 10;
for (;;) {
spin_lock_irq(¤t->sigmask_lock);
siginitsetinv (¤t->blocked, sigmask(SIGHUP) | sigmask(SIGKILL) | sigmask(SIGSTOP) | sigmask(SIGCONT));
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
if (!thread_should_wake(c)) {
set_current_state (TASK_INTERRUPTIBLE);
D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n"));
/* Yes, there's a race here; we checked 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();
}
if (current->need_resched)
schedule();
/* Put_super will send a SIGKILL and then wait on the sem.
*/
while (signal_pending(current)) {
siginfo_t info;
unsigned long signr;
spin_lock_irq(¤t->sigmask_lock);
signr = dequeue_signal(¤t->blocked, &info);
spin_unlock_irq(¤t->sigmask_lock);
switch(signr) {
case SIGSTOP:
D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGSTOP received.\n"));
set_current_state(TASK_STOPPED);
schedule();
break;
case SIGKILL:
D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGKILL received.\n"));
spin_lock_bh(&c->erase_completion_lock);
c->gc_task = NULL;
spin_unlock_bh(&c->erase_completion_lock);
complete_and_exit(&c->gc_thread_exit, 0);
case SIGHUP:
D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGHUP received.\n"));
break;
default:
D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): signal %ld received\n", signr));
}
}
/* We don't want SIGHUP to interrupt us. STOP and KILL are OK though. */
spin_lock_irq(¤t->sigmask_lock);
siginitsetinv (¤t->blocked, sigmask(SIGKILL) | sigmask(SIGSTOP) | sigmask(SIGCONT));
recalc_sigpending(current);
spin_unlock_irq(¤t->sigmask_lock);
D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): pass\n"));
jffs2_garbage_collect_pass(c);
}
}
static int thread_should_wake(struct jffs2_sb_info *c)
{
D1(printk(KERN_DEBUG "thread_should_wake(): nr_free_blocks %d, nr_erasing_blocks %d, dirty_size 0x%x\n",
c->nr_free_blocks, c->nr_erasing_blocks, c->dirty_size));
if (c->nr_free_blocks + c->nr_erasing_blocks < JFFS2_RESERVED_BLOCKS_GCTRIGGER &&
c->dirty_size > c->sector_size)
return 1;
else
return 0;
}
|
