[SPDK] Rocksdb with SPDK

Hi all, 

I am running Rocksdb on top of a blobfs filesystem and I have a couple of questions. 

1. What exactly does the ```sanitize_path()``` function do and why do we need to sanitize the path before opening a file? If the fname is /mnt/rocksdb/log, the sanitize path returns /log .. What does that means for my application?
2. the file->Sync() operations fails with a message "Not Implemented". In particular, I am having the following code :

```
if (!FLAGS__spdk.empty()) {
                        FLAGS_env = rocksdb::NewSpdkEnv(FLAGS_env, FLAGS_dir, FLAGS__spdk, FLAGS__spdk_bdev, FLAGS__spdk_cache_size);
                        fprintf(stdout, "Using rocksdb::NewSpdkEnv() environment.\n");
                        if (FLAGS_env == nullptr) {
                                fprintf(stderr, "Could not load SPDK blobfs - check that SPDK mkfs was run "
                                                "against block device %s.\n", FLAGS__spdk_bdev.c_str());
                                exit(1);
                        } 
                }

                unique_ptr<WritableFile> file;
                EnvOptions soptions;

                rocksdb::Slice data = return_data(FLAGS__value_size);
                Status s = FLAGS_env->NewWritableFile(FLAGS_file, &file, soptions);
                if (!s.ok()) {
                        fprintf(stderr, "oops ..\n");
                        abort();
                }

                size_t size = 0;
                size_t total_size = FLAGS_total_size*1024;
                struct timeval start_time, end_time;
                gettimeofday(&start_time, NULL);
                while (size < total_size) {
                        s = file->Append(data);

                        if (s.ok()) {
                                s = file->Sync();
                        }

                        size += FLAGS__value_size;

                        if (!s.ok()) {
                                fprintf(stdout, "written %d bytes to %s (%s)..\n", size, FLAGS_file.c_str(), s.ToString().c_str());
                                abort();
                        }
                }
```

However, I am seeing that the rocksdb::SpdkWritableFile::Sync() is implemented ..
Any ideas?
Thanks for your help :)

Dimitra