Following this question: How to quickly create large files in C?
I remember 4-5 years ago, I was able to use fallocate shell utility in Linux to create files without holes/gaps.
磁盘文件系统是ext3，ext4或xfs。
At that time, fallocate shell utility created files of 8 GB in less one second. I do not remember if file was full of zeroes or random.
我现在尝试复制此文件，但似乎创建带有漏洞/空白的文件。
I am wondering how this was done in C language?
- 某些内核调用仅是Linux？
- 某些内核调用中的规范错误后来被修复？
- 一些内核调用不再可用？
