CreateAndSyncFile creates a file, writes the content and syncs the file.

CreateAndSyncFileAtomically writes the content to the tmpFile, fsyncs the tmpFile, renames the tmpFile to the finalFile.

CreateDirIfMissing makes sure that the dir exists and returns whether the dir is empty.

DirEmpty returns true if the dir at dirPath is empty.

DirExists returns true if the dir already exists.

FileExists checks whether the given file exists.

ListSubdirs returns the subdirectories.

RemoveContents removes all the files and subdirs under the specified directory.

SyncDir fsyncs the given dir.

SyncParentDir fsyncs the parent dir of the given path.