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[JFFS2] Fix lack of locking in thread_should_wake()
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
+5
-5
fs/jffs2/background.c
+5
-5
fs/jffs2/background.c
···
85
for (;;) {
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allow_signal(SIGHUP);
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again:
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if (!jffs2_thread_should_wake(c)) {
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set_current_state (TASK_INTERRUPTIBLE);
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D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n"));
91
-
/* Yes, there's a race here; we checked jffs2_thread_should_wake()
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-
before setting current->state to TASK_INTERRUPTIBLE. But it doesn't
93
-
matter - We don't care if we miss a wakeup, because the GC thread
94
-
is only an optimisation anyway. */
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schedule();
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-
}
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98
/* This thread is purely an optimisation. But if it runs when
99
other things could be running, it actually makes things a
···
85
for (;;) {
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allow_signal(SIGHUP);
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again:
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+
spin_lock(&c->erase_completion_lock);
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if (!jffs2_thread_should_wake(c)) {
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set_current_state (TASK_INTERRUPTIBLE);
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+
spin_unlock(&c->erase_completion_lock);
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D1(printk(KERN_DEBUG "jffs2_garbage_collect_thread sleeping...\n"));
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schedule();
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+
} else
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+
spin_unlock(&c->erase_completion_lock);
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+
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/* This thread is purely an optimisation. But if it runs when
99
other things could be running, it actually makes things a