On Wed, Jan 27, 2021 at 11:21:08AM -0500, Josef Bacik wrote:

On 1/26/21 3:33 AM, Qu Wenruo wrote:

quoted

--- a/fs/btrfs/subpage.h
+++ b/fs/btrfs/subpage.h

@@ -4,6 +4,7 @@
  #define BTRFS_SUBPAGE_H
  
  #include <linux/spinlock.h>
+#include <linux/refcount.h>

I made this comment elsewhere, but the patch finally showed up in my email after 
I refreshed (???? thunderbird wtf??).  Anyway you import refcount.h here, but 
don't actually use refcount_t.  Please use refcount_t, so we get the benefit of 
the debugging from the helpers.  Thanks,

Switching to refcount looks a bit complicated so for now let's use
atomics, it's affecting only the subpage case.