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[JFFS2] Fix lack of locking in thread_should_wake()

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The thread_should_wake() function trawls through the list of 'very
dirty' eraseblocks, determining whether the background GC thread should
wake. Doing this without holding the appropriate locks is a bad idea.

OLPC Trac #8615

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org
This commit is contained in:
David Woodhouse 2008-10-31 14:52:24 +00:00
parent f04de505e3
commit b27cf88e95
1 changed files with 5 additions and 5 deletions
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10
fs/jffs2/background.c
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@ -85,15 +85,15 @@ static int jffs2_garbage_collect_thread(void *_c)
for (;;) {
allow_signal(SIGHUP);
again:
spin_lock(&c->erase_completion_lock);
if (!jffs2_thread_should_wake(c)) {
set_current_state (TASK_INTERRUPTIBLE);
spin_unlock(&c->erase_completion_lock);
D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n"));
/* Yes, there's a race here; we checked jffs2_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();
}
} else
spin_unlock(&c->erase_completion_lock);
/* This thread is purely an optimisation. But if it runs when
other things could be running, it actually makes things a