GIT: unionfs2-2.6.27.y: trace: Fix inappropriate substraction on tracing_pages_allocated in trace_free_page()

[Erez Zadok]

commit 0851f4563b9e0770d4b3c071e605cb5e150c6ed3
Author: Wang Sheng-Hui <crosslonelyover at gmail.com>
Date:   Tue Apr 13 21:04:10 2010 +0800

    trace: Fix inappropriate substraction on tracing_pages_allocated in trace_free_page()
    
    [No matching upstream git commit id as it was fixed differently due to a
    rewrite of the tracing code there.]
    
    For normal case, the code in trace_free_page() do once more substraction
    on tracing_pages_allocated, but for CONFIG_TRACER_MAX_TRACE Â it doesn't
    take the freed page into account. That's not consistent with
    trace_alloc_page().  Well, for there are no message related with this,
    so we cannot observe its incorrect state when the kernel doesn't define
    "CONFIG_TRACER_MAX_TRACE". If you add some pr_info() as
    trace_alloc_page(), you may notice it.
    
    Cc: Steven Rostedt <rostedt at goodmis.org>
    Cc: Frederic Weisbecker <fweisbec at gmail.com>
    Cc: Ingo Molnar <mingo at redhat.com>
    Cc: Li Zefan <lizf at cn.fujitsu.com>
    Signed-off-by: Wang Sheng-Hui <crosslonelyover at gmail.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh at suse.de>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8f3fb3d..dfe3995 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3018,7 +3018,6 @@ static int trace_free_page(void)
 		ClearPageLRU(page);
 		list_del(&page->lru);
 		tracing_pages_allocated--;
-		tracing_pages_allocated--;
 		__free_page(page);
 
 		tracing_reset(data);
@@ -3036,6 +3035,7 @@ static int trace_free_page(void)
 		page = list_entry(p, struct page, lru);
 		ClearPageLRU(page);
 		list_del(&page->lru);
+		tracing_pages_allocated--;
 		__free_page(page);
 
 		tracing_reset(data);