Commits
Yan, Zheng committed 86056090496
ceph: avoid sending unnessesary FLUSHSNAP message when a snap notification contains no new snapshot, we can avoid sending FLUSHSNAP message to MDS. But we still need to create cap_snap in some case because it's required by write path and page writeback path Signed-off-by: Yan, Zheng <zyan@redhat.com>