Method statvfs

fs/cache/cached_fs.cpp:98–100

        return srcFs_ ? srcFs_->statfs(path, buf) : -1;
    }
    int statvfs(const char *path, struct statvfs *buf) override {
        return srcFs_ ? srcFs_->statvfs(path, buf) : -1;
    }
    int stat(const char *path, struct stat *buf) override {
        return srcFs_ ? srcFs_->stat(path, buf) : -1;
    }