On Fri, May 13, 2016 at 05:06:59PM -0700, Liu Bo wrote:

While reading sys_chunk_array in superblock, btrfs creates a temporary
extent buffer.  Since we don't use it after finishing reading
 sys_chunk_array, we don't need to keep it in memory.

Signed-off-by: Liu Bo <redacted>

This patch is independent of the rest, I'll add it to next.