> For the complete documentation index, see [llms.txt](https://nankai.gitbook.io/ucore-os-on-risc-v64/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nankai.gitbook.io/ucore-os-on-risc-v64/lab8/lian-xi.md).

# 练习

## 练习1：填写sfs\_io\_nolock()函数

首先了解打开文件的处理流程，然后参考本实验后续的文件读写操作的过程分析，填写在 `kern/fs/sfs/sfs_inode.c`中 的`sfs_io_nolock()`函数，实现读文件中数据的代码。

## 练习2：填写load\_icode()函数

改写 proc.c 中的 load\_icode 函数和其他相关函数，实现基于文件系统的执行程序机制。执行：make qemu。如果能看看到 sh 用户程序的执行界面，则基本成功了。如果在 sh 用户界面上可以执行”ls”,”hello”等其他放置在 sfs 文件系统中的其他执行程序，则可以认为本实验基本成功。

## 练习3：管道（Pipe)机制

如果要在ucore里加入UNIX的管道（Pipe)机制，至少需要定义哪些数据结构和接口？（接口给出语义即可，不必具体实现。数据结构的设计应当给出一个(或多个）具体的C语言struct定义。你的设计应当体现出对可能出现的同步互斥问题的处理。


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