Summary:
Previously, if blob_db_options.bytes_per_sync, there is a background job to call fsync() for every bytes_per_sync bytes written to a blob file. With the change we simply pass bytes_per_sync as env_options_ to blob files so that sync_file_range() will be used instead.
Closes https://github.com/facebook/rocksdb/pull/3297
Differential Revision: D6606994
Pulled By: yiwu-arbug
fbshipit-source-id: 452424be52e32ba92f5ea603b564e9b88929af47
5efc4bd8ea