HDFS-17861. The mis-behavior of commitBlockSynchronization may cause standby namenode and observer namenode crash.#8120

hfutatzhanghb wants to merge 2 commits intoapache:trunkapache/hadoop:trunkfrom

hfutatzhanghb:HDFS-17861hfutatzhanghb/hadoop:HDFS-17861Copy head branch name to clipboard