ceph/ceph — pull request #1048 by yuyuyu101 (2014-01-06 03:57:13+00:00)
Title: Avoid leveldb check for xattr when possible

Maintain a intern xattr called "spill_out" that indicates whether spilling
over into DBObjectMap. If not present, assume this is old style object and
look in DBObjectMap. Then if no xattrs in DBObjectMap, this xattr(spill_out)
also will be set to indicate.

implement #7059

Signed-off-by: Haomai Wang