Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * JFFS2 -- Journalling Flash File System, Version 2. |
| 3 | * |
David Woodhouse | c00c310 | 2007-04-25 14:16:47 +0100 | [diff] [blame] | 4 | * Copyright © 2001-2007 Red Hat, Inc. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 5 | * |
| 6 | * Created by David Woodhouse <dwmw2@infradead.org> |
| 7 | * |
| 8 | * For licensing information, see the file 'LICENCE' in this directory. |
| 9 | * |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | */ |
| 11 | |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/jffs2.h> |
| 14 | #include <linux/mtd/mtd.h> |
| 15 | #include <linux/completion.h> |
Tim Schmielau | 4e57b68 | 2005-10-30 15:03:48 -0800 | [diff] [blame] | 16 | #include <linux/sched.h> |
Nigel Cunningham | 7dfb710 | 2006-12-06 20:34:23 -0800 | [diff] [blame] | 17 | #include <linux/freezer.h> |
Gerard Lledo | 91e0955 | 2009-06-17 13:08:55 -0700 | [diff] [blame] | 18 | #include <linux/kthread.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include "nodelist.h" |
| 20 | |
| 21 | |
| 22 | static int jffs2_garbage_collect_thread(void *); |
| 23 | |
| 24 | void jffs2_garbage_collect_trigger(struct jffs2_sb_info *c) |
| 25 | { |
David Woodhouse | acb64a4 | 2010-05-19 17:00:10 +0100 | [diff] [blame] | 26 | assert_spin_locked(&c->erase_completion_lock); |
David Woodhouse | ef53cb0 | 2007-07-10 10:01:22 +0100 | [diff] [blame] | 27 | if (c->gc_task && jffs2_thread_should_wake(c)) |
| 28 | send_sig(SIGHUP, c->gc_task, 1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 29 | } |
| 30 | |
| 31 | /* This must only ever be called when no GC thread is currently running */ |
| 32 | int jffs2_start_garbage_collect_thread(struct jffs2_sb_info *c) |
| 33 | { |
Gerard Lledo | 91e0955 | 2009-06-17 13:08:55 -0700 | [diff] [blame] | 34 | struct task_struct *tsk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 35 | int ret = 0; |
| 36 | |
Eric Sesterhenn | 4b4d1cc | 2006-04-01 01:15:35 +0200 | [diff] [blame] | 37 | BUG_ON(c->gc_task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 38 | |
Thomas Gleixner | fff7afd | 2005-05-19 17:18:11 +0100 | [diff] [blame] | 39 | init_completion(&c->gc_thread_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | init_completion(&c->gc_thread_exit); |
| 41 | |
Gerard Lledo | 91e0955 | 2009-06-17 13:08:55 -0700 | [diff] [blame] | 42 | tsk = kthread_run(jffs2_garbage_collect_thread, c, "jffs2_gcd_mtd%d", c->mtd->index); |
| 43 | if (IS_ERR(tsk)) { |
| 44 | printk(KERN_WARNING "fork failed for JFFS2 garbage collect thread: %ld\n", -PTR_ERR(tsk)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 45 | complete(&c->gc_thread_exit); |
Gerard Lledo | 91e0955 | 2009-06-17 13:08:55 -0700 | [diff] [blame] | 46 | ret = PTR_ERR(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 47 | } else { |
| 48 | /* Wait for it... */ |
Gerard Lledo | 91e0955 | 2009-06-17 13:08:55 -0700 | [diff] [blame] | 49 | D1(printk(KERN_DEBUG "JFFS2: Garbage collect thread is pid %d\n", tsk->pid)); |
Thomas Gleixner | fff7afd | 2005-05-19 17:18:11 +0100 | [diff] [blame] | 50 | wait_for_completion(&c->gc_thread_start); |
Gerard Lledo | 91e0955 | 2009-06-17 13:08:55 -0700 | [diff] [blame] | 51 | ret = tsk->pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | } |
Thomas Gleixner | 182ec4e | 2005-11-07 11:16:07 +0000 | [diff] [blame] | 53 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | return ret; |
| 55 | } |
| 56 | |
| 57 | void jffs2_stop_garbage_collect_thread(struct jffs2_sb_info *c) |
| 58 | { |
Thomas Gleixner | e2d48b1 | 2005-05-20 22:37:15 +0100 | [diff] [blame] | 59 | int wait = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 60 | spin_lock(&c->erase_completion_lock); |
| 61 | if (c->gc_task) { |
| 62 | D1(printk(KERN_DEBUG "jffs2: Killing GC task %d\n", c->gc_task->pid)); |
| 63 | send_sig(SIGKILL, c->gc_task, 1); |
Thomas Gleixner | e2d48b1 | 2005-05-20 22:37:15 +0100 | [diff] [blame] | 64 | wait = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | } |
| 66 | spin_unlock(&c->erase_completion_lock); |
Thomas Gleixner | e2d48b1 | 2005-05-20 22:37:15 +0100 | [diff] [blame] | 67 | if (wait) |
| 68 | wait_for_completion(&c->gc_thread_exit); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 69 | } |
| 70 | |
| 71 | static int jffs2_garbage_collect_thread(void *_c) |
| 72 | { |
| 73 | struct jffs2_sb_info *c = _c; |
| 74 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | allow_signal(SIGKILL); |
| 76 | allow_signal(SIGSTOP); |
| 77 | allow_signal(SIGCONT); |
| 78 | |
| 79 | c->gc_task = current; |
Thomas Gleixner | fff7afd | 2005-05-19 17:18:11 +0100 | [diff] [blame] | 80 | complete(&c->gc_thread_start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 81 | |
| 82 | set_user_nice(current, 10); |
| 83 | |
Rafael J. Wysocki | 8314418 | 2007-07-17 04:03:35 -0700 | [diff] [blame] | 84 | set_freezable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 85 | for (;;) { |
| 86 | allow_signal(SIGHUP); |
David Woodhouse | e716dd3 | 2007-06-28 19:49:36 +0100 | [diff] [blame] | 87 | again: |
David Woodhouse | b27cf88 | 2008-10-31 14:52:24 +0000 | [diff] [blame] | 88 | spin_lock(&c->erase_completion_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 89 | if (!jffs2_thread_should_wake(c)) { |
| 90 | set_current_state (TASK_INTERRUPTIBLE); |
David Woodhouse | b27cf88 | 2008-10-31 14:52:24 +0000 | [diff] [blame] | 91 | spin_unlock(&c->erase_completion_lock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n")); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | schedule(); |
David Woodhouse | b27cf88 | 2008-10-31 14:52:24 +0000 | [diff] [blame] | 94 | } else |
| 95 | spin_unlock(&c->erase_completion_lock); |
| 96 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 97 | |
Andres Salomon | efab0b5 | 2009-02-11 13:27:02 -0800 | [diff] [blame] | 98 | /* Problem - immediately after bootup, the GCD spends a lot |
| 99 | * of time in places like jffs2_kill_fragtree(); so much so |
| 100 | * that userspace processes (like gdm and X) are starved |
| 101 | * despite plenty of cond_resched()s and renicing. Yield() |
| 102 | * doesn't help, either (presumably because userspace and GCD |
| 103 | * are generally competing for a higher latency resource - |
| 104 | * disk). |
| 105 | * This forces the GCD to slow the hell down. Pulling an |
| 106 | * inode in with read_inode() is much preferable to having |
| 107 | * the GC thread get there first. */ |
| 108 | schedule_timeout_interruptible(msecs_to_jiffies(50)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 109 | |
Gerard Lledo | 91e0955 | 2009-06-17 13:08:55 -0700 | [diff] [blame] | 110 | if (kthread_should_stop()) { |
| 111 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): kthread_stop() called.\n")); |
| 112 | goto die; |
| 113 | } |
| 114 | |
Thomas Gleixner | 182ec4e | 2005-11-07 11:16:07 +0000 | [diff] [blame] | 115 | /* Put_super will send a SIGKILL and then wait on the sem. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | */ |
Rafael J. Wysocki | e136e76 | 2007-12-04 01:11:09 +0100 | [diff] [blame] | 117 | while (signal_pending(current) || freezing(current)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | siginfo_t info; |
| 119 | unsigned long signr; |
| 120 | |
David Woodhouse | e716dd3 | 2007-06-28 19:49:36 +0100 | [diff] [blame] | 121 | if (try_to_freeze()) |
| 122 | goto again; |
| 123 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 124 | signr = dequeue_signal_lock(current, ¤t->blocked, &info); |
| 125 | |
| 126 | switch(signr) { |
| 127 | case SIGSTOP: |
| 128 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGSTOP received.\n")); |
| 129 | set_current_state(TASK_STOPPED); |
| 130 | schedule(); |
| 131 | break; |
| 132 | |
| 133 | case SIGKILL: |
| 134 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGKILL received.\n")); |
| 135 | goto die; |
| 136 | |
| 137 | case SIGHUP: |
| 138 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): SIGHUP received.\n")); |
| 139 | break; |
| 140 | default: |
| 141 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): signal %ld received\n", signr)); |
| 142 | } |
| 143 | } |
| 144 | /* We don't want SIGHUP to interrupt us. STOP and KILL are OK though. */ |
| 145 | disallow_signal(SIGHUP); |
| 146 | |
| 147 | D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread(): pass\n")); |
| 148 | if (jffs2_garbage_collect_pass(c) == -ENOSPC) { |
| 149 | printk(KERN_NOTICE "No space for garbage collection. Aborting GC thread\n"); |
| 150 | goto die; |
| 151 | } |
| 152 | } |
| 153 | die: |
| 154 | spin_lock(&c->erase_completion_lock); |
| 155 | c->gc_task = NULL; |
| 156 | spin_unlock(&c->erase_completion_lock); |
| 157 | complete_and_exit(&c->gc_thread_exit, 0); |
| 158 | } |