Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | * |
Thomas Gleixner | e2d48b1 | 2005-05-20 22:37:15 +0100 | [diff] [blame] | 10 | * $Id: background.c,v 1.54 2005/05/20 21:37:12 gleixner Exp $ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | * |
| 12 | */ |
| 13 | |
| 14 | #include <linux/kernel.h> |
| 15 | #include <linux/jffs2.h> |
| 16 | #include <linux/mtd/mtd.h> |
| 17 | #include <linux/completion.h> |
Tim Schmielau | 4e57b68 | 2005-10-30 15:03:48 -0800 | [diff] [blame] | 18 | #include <linux/sched.h> |
Nigel Cunningham | 7dfb710 | 2006-12-06 20:34:23 -0800 | [diff] [blame] | 19 | #include <linux/freezer.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 20 | #include "nodelist.h" |
| 21 | |
| 22 | |
| 23 | static int jffs2_garbage_collect_thread(void *); |
| 24 | |
| 25 | void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c) |
| 26 | { |
| 27 | spin_lock(&c->erase_completion_lock); |
| 28 | if (c->gc_task && jffs2_thread_should_wake(c)) |
| 29 | send_sig(SIGHUP, c->gc_task, 1); |
| 30 | spin_unlock(&c->erase_completion_lock); |
| 31 | } |
| 32 | |
| 33 | /* This must only ever be called when no GC thread is currently running */ |
| 34 | int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) |
| 35 | { |
| 36 | pid_t pid; |
| 37 | int ret = 0; |
| 38 | |
Eric Sesterhenn | 4b4d1cc | 2006-04-01 01:15:35 +0200 | [diff] [blame] | 39 | BUG_ON(c->gc_task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
Thomas Gleixner | fff7afd | 2005-05-19 17:18:11 +0100 | [diff] [blame] | 41 | init_completion(&c->gc_thread_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | init_completion(&c->gc_thread_exit); |
| 43 | |
| 44 | pid = kernel_thread(jffs2_garbage_collect_thread, c, CLONE_FS|CLONE_FILES); |
| 45 | if (pid < 0) { |
| 46 | printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %d\n", -pid); |
| 47 | complete(&c->gc_thread_exit); |
| 48 | ret = pid; |
| 49 | } else { |
| 50 | /* Wait for it... */ |
| 51 | D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", pid)); |
Thomas Gleixner | fff7afd | 2005-05-19 17:18:11 +0100 | [diff] [blame] | 52 | wait_for_completion(&c->gc_thread_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 53 | } |
Thomas Gleixner | 182ec4e | 2005-11-07 11:16:07 +0000 | [diff] [blame] | 54 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 55 | return ret; |
| 56 | } |
| 57 | |
| 58 | void jffs2_stop_garbage_collect_thread(struct jffs2_sb_info *c) |
| 59 | { |
Thomas Gleixner | e2d48b1 | 2005-05-20 22:37:15 +0100 | [diff] [blame] | 60 | int wait = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | spin_lock(&c->erase_completion_lock); |
| 62 | if (c->gc_task) { |
| 63 | D1(printk(KERN_DEBUG "jffs2: Killing GC task %d\n", c->gc_task->pid)); |
| 64 | send_sig(SIGKILL, c->gc_task, 1); |
Thomas Gleixner | e2d48b1 | 2005-05-20 22:37:15 +0100 | [diff] [blame] | 65 | wait = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 66 | } |
| 67 | spin_unlock(&c->erase_completion_lock); |
Thomas Gleixner | e2d48b1 | 2005-05-20 22:37:15 +0100 | [diff] [blame] | 68 | if (wait) |
| 69 | wait_for_completion(&c->gc_thread_exit); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 70 | } |
| 71 | |
| 72 | static int jffs2_garbage_collect_thread(void *_c) |
| 73 | { |
| 74 | struct jffs2_sb_info *c = _c; |
| 75 | |
| 76 | daemonize("jffs2_gcd_mtd%d", c->mtd->index); |
| 77 | allow_signal(SIGKILL); |
| 78 | allow_signal(SIGSTOP); |
| 79 | allow_signal(SIGCONT); |
| 80 | |
| 81 | c->gc_task = current; |
Thomas Gleixner | fff7afd | 2005-05-19 17:18:11 +0100 | [diff] [blame] | 82 | complete(&c->gc_thread_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 83 | |
| 84 | set_user_nice(current, 10); |
| 85 | |
| 86 | for (;;) { |
| 87 | allow_signal(SIGHUP); |
| 88 | |
| 89 | if (!jffs2_thread_should_wake(c)) { |
| 90 | set_current_state (TASK_INTERRUPTIBLE); |
| 91 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n")); |
| 92 | /* Yes, there's a race here; we checked jffs2_thread_should_wake() |
| 93 | before setting current->state to TASK_INTERRUPTIBLE. But it doesn't |
| 94 | matter - We don't care if we miss a wakeup, because the GC thread |
| 95 | is only an optimisation anyway. */ |
| 96 | schedule(); |
| 97 | } |
| 98 | |
Andrew Morton | 34f18a9 | 2005-06-26 03:27:20 -0700 | [diff] [blame] | 99 | if (try_to_freeze()) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | continue; |
| 101 | |
| 102 | cond_resched(); |
| 103 | |
Thomas Gleixner | 182ec4e | 2005-11-07 11:16:07 +0000 | [diff] [blame] | 104 | /* Put_super will send a SIGKILL and then wait on the sem. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | */ |
| 106 | while (signal_pending(current)) { |
| 107 | siginfo_t info; |
| 108 | unsigned long signr; |
| 109 | |
| 110 | signr = dequeue_signal_lock(current, ¤t->blocked, &info); |
| 111 | |
| 112 | switch(signr) { |
| 113 | case SIGSTOP: |
| 114 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGSTOP received.\n")); |
| 115 | set_current_state(TASK_STOPPED); |
| 116 | schedule(); |
| 117 | break; |
| 118 | |
| 119 | case SIGKILL: |
| 120 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGKILL received.\n")); |
| 121 | goto die; |
| 122 | |
| 123 | case SIGHUP: |
| 124 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGHUP received.\n")); |
| 125 | break; |
| 126 | default: |
| 127 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): signal %ld received\n", signr)); |
| 128 | } |
| 129 | } |
| 130 | /* We don't want SIGHUP to interrupt us. STOP and KILL are OK though. */ |
| 131 | disallow_signal(SIGHUP); |
| 132 | |
| 133 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): pass\n")); |
| 134 | if (jffs2_garbage_collect_pass(c) == -ENOSPC) { |
| 135 | printk(KERN_NOTICE "No space for garbage collection. Aborting GC thread\n"); |
| 136 | goto die; |
| 137 | } |
| 138 | } |
| 139 | die: |
| 140 | spin_lock(&c->erase_completion_lock); |
| 141 | c->gc_task = NULL; |
| 142 | spin_unlock(&c->erase_completion_lock); |
| 143 | complete_and_exit(&c->gc_thread_exit, 0); |
| 144 | } |