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  126.   实验-文件系统
    127. 

  127. </a></li></ul></li></ul></div></div> <!----></nav>  <ul class="sidebar-links"><li><section class="sidebar-group depth-0"><p class="sidebar-heading open"><span>文件系统</span> <!----></p> <ul class="sidebar-links sidebar-group-items"><li><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#补写代码" class="sidebar-link">补写代码</a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#创建文件" class="sidebar-link">创建文件</a></li><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#文件读写" class="sidebar-link">文件读写</a></li></ul></li><li><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#实现-myramfs" class="sidebar-link">实现 myramfs</a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#open和close" class="sidebar-link">open和close</a></li><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#fopen" class="sidebar-link">fopen</a></li></ul></li><li><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#测试文件系统" class="sidebar-link">测试文件系统</a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#创建测试文件夹" class="sidebar-link">创建测试文件夹</a></li><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#配置文件" class="sidebar-link">配置文件</a></li></ul></li><li><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#配置dadk" class="sidebar-link">配置dadk</a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#拷贝文件-2" class="sidebar-link">拷贝文件</a></li><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#更改dadk内容" class="sidebar-link">更改dadk内容</a></li></ul></li><li><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#挂载文件系统" class="sidebar-link">挂载文件系统</a><ul class="sidebar-sub-headers"><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#导入" class="sidebar-link">导入</a></li><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#创建文件夹、实例并挂载" class="sidebar-link">创建文件夹、实例并挂载</a></li><li class="sidebar-sub-header"><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#迁移伪文件系统的inode" class="sidebar-link">迁移伪文件系统的inode</a></li></ul></li><li><a href="/OS_lab_tutorial/DragonOS/Assignment/Lab1.html#开始测试" class="sidebar-link">开始测试</a><ul class="sidebar-sub-headers"></ul></li></ul></section></li></ul> </aside> <main class="page"> <div class="theme-default-content content__default"><h1 id="文件系统"><a href="#文件系统" class="header-anchor">#</a> 文件系统</h1> <h2 id="补写代码"><a href="#补写代码" class="header-anchor">#</a> 补写代码</h2> <h3 id="创建文件"><a href="#创建文件" class="header-anchor">#</a> 创建文件</h3> <p>ramfs的基本功能在/kernel/src/filesystem/ramfs/mod.rs中，实现过程中请参考文件../vfs/mod.rs以及已实现函数的相关代码和注释。在实现基本的文件操作之前，需要先实现创建文件结构的辅助函数：create_with_data。其用于创建文件时，在父目录下创建带初始化数据的inode。</p> <blockquote><p>练习1：实现位于/kernel/src/filesystem/ramfs/mod.rs中的 create_with_data。</p></blockquote> <div class="language-rust extra-class"><pre class="language-rust"><code>    <span class="token comment">// 该函数用于在当前目录下创建一个新的inode，并传入一个简单的data字段，方便进行初始化。</span>
    128. 

  128.     <span class="token comment">// 需要判断当前inode是否是文件且是否重名，接着创建inode进行初始化。</span>
    129. 

  129.     <span class="token keyword">fn</span> <span class="token function-definition function">create_with_data</span><span class="token punctuation">(</span>
    130. 

  130.         <span class="token operator">&amp;</span><span class="token keyword">self</span><span class="token punctuation">,</span>
    131. 

  131.         name<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">str</span><span class="token punctuation">,</span>
    132. 

  132.         file_type<span class="token punctuation">:</span> <span class="token class-name">FileType</span><span class="token punctuation">,</span>
    133. 

  133.         mode<span class="token punctuation">:</span> <span class="token keyword">u32</span><span class="token punctuation">,</span>
    134. 

  134.         data<span class="token punctuation">:</span> <span class="token keyword">usize</span><span class="token punctuation">,</span>
    135. 

  135.     <span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token class-name">Arc</span><span class="token operator">&lt;</span><span class="token keyword">dyn</span> <span class="token class-name">IndexNode</span><span class="token operator">&gt;</span><span class="token punctuation">,</span> <span class="token class-name">SystemError</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
    136. 

  136.         <span class="token comment">// 获取当前inode</span>
    137. 

  137.         <span class="token keyword">let</span> <span class="token keyword">mut</span> inode <span class="token operator">=</span> <span class="token keyword">self</span><span class="token punctuation">.</span><span class="token number">0</span><span class="token punctuation">.</span><span class="token function">lock</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    138. 

  138.         
    139. 

  139.         <span class="token comment">// LAB TODO BEGIN</span>
    140. 

  140. 

  141.         <span class="token comment">// LAB TODO END</span>
    142. 

  142. 

  143.         <span class="token comment">// 初始化inode的自引用的weak指针</span>
    144. 

  144.         result<span class="token number">.0</span><span class="token punctuation">.</span><span class="token function">lock</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span>self_ref <span class="token operator">=</span> <span class="token class-name">Arc</span><span class="token punctuation">::</span><span class="token function">downgrade</span><span class="token punctuation">(</span><span class="token operator">&amp;</span>result<span class="token punctuation">)</span><span class="token punctuation">;</span>
    145. 

  145. 

  146.         <span class="token comment">// 将子inode插入父inode的B树中</span>
    147. 

  147.         inode<span class="token punctuation">.</span>children<span class="token punctuation">.</span><span class="token function">insert</span><span class="token punctuation">(</span><span class="token class-name">String</span><span class="token punctuation">::</span><span class="token function">from</span><span class="token punctuation">(</span>name<span class="token punctuation">)</span><span class="token punctuation">,</span> result<span class="token punctuation">.</span><span class="token function">clone</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    148. 

  148. 

  149.         <span class="token keyword">return</span> <span class="token class-name">Ok</span><span class="token punctuation">(</span>result<span class="token punctuation">)</span><span class="token punctuation">;</span>
    150. 

  150.     <span class="token punctuation">}</span>
    151. 

  151. </code></pre></div><h3 id="文件读写"><a href="#文件读写" class="header-anchor">#</a> 文件读写</h3> <p>文件读写是文件系统的基本功能，ramfs的读写操作会将文件数据块中内容读入内存缓冲区，或将缓冲区内容写入对应文件数据块。<code>read_at</code>和 <code>write_at</code>两个函数分别用于以一定偏移量读取和写入一段长度的数据，并且返回实际的读写字节长度 （读取不能超过文件大小）</p> <blockquote><p>练习2：实现位于/kernel/src/filesystem/ramfs/mod.rs中的 read_at和 write_at。</p></blockquote> <div class="language-rust extra-class"><pre class="language-rust"><code>    <span class="token comment">// 该函数用于实现对文件以一定偏移量读取一段长度的数据，并且返回实际的读字节长度。</span>
    152. 

  152.     <span class="token comment">// 首先检查当前inode是否为一个文件，然后计算读文件的偏移量，最后拷贝数据（copy_from_slice）。</span>
    153. 

  153.     <span class="token keyword">fn</span> <span class="token function-definition function">read_at</span><span class="token punctuation">(</span>
    154. 

  154.         <span class="token operator">&amp;</span><span class="token keyword">self</span><span class="token punctuation">,</span>
    155. 

  155.         offset<span class="token punctuation">:</span> <span class="token keyword">usize</span><span class="token punctuation">,</span>
    156. 

  156.         len<span class="token punctuation">:</span> <span class="token keyword">usize</span><span class="token punctuation">,</span>
    157. 

  157.         buf<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">mut</span> <span class="token punctuation">[</span><span class="token keyword">u8</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
    158. 

  158.         _data<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">mut</span> <span class="token class-name">FilePrivateData</span><span class="token punctuation">,</span>
    159. 

  159.     <span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token keyword">usize</span><span class="token punctuation">,</span> <span class="token class-name">SystemError</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
    160. 

  160.         <span class="token keyword">if</span> buf<span class="token punctuation">.</span><span class="token function">len</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">&lt;</span> len <span class="token punctuation">{</span>
    161. 

  161.             <span class="token keyword">return</span> <span class="token class-name">Err</span><span class="token punctuation">(</span><span class="token class-name">SystemError</span><span class="token punctuation">::</span><span class="token constant">EINVAL</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    162. 

  162.         <span class="token punctuation">}</span>
    163. 

  163.         <span class="token comment">// 加锁</span>
    164. 

  164.         <span class="token keyword">let</span> inode<span class="token punctuation">:</span> <span class="token class-name">SpinLockGuard</span><span class="token operator">&lt;</span><span class="token class-name">RamFSInode</span><span class="token operator">&gt;</span> <span class="token operator">=</span> <span class="token keyword">self</span><span class="token punctuation">.</span><span class="token number">0</span><span class="token punctuation">.</span><span class="token function">lock</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    165. 

  165. 

  166.         <span class="token comment">// LAB TODO BEGIN</span>
    167. 

  167. 

  168.         <span class="token comment">// LAB TODO END</span>
    169. 

  169. 

  170.         <span class="token keyword">return</span> <span class="token class-name">Ok</span><span class="token punctuation">(</span>src<span class="token punctuation">.</span><span class="token function">len</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    171. 

  171.     <span class="token punctuation">}</span>
    172. 

  172. 

  173.     <span class="token comment">// 该函数用于实现对文件以一定偏移量写一段长度的数据，并且返回实际的写字节长度。</span>
    174. 

  174.     <span class="token comment">// 首先检查当前inode是否为一个文件，如果文件大小比原来的大，那就resize这个数组，最后将数据写入（copy_from_slice）。</span>
    175. 

  175.     <span class="token keyword">fn</span> <span class="token function-definition function">write_at</span><span class="token punctuation">(</span>
    176. 

  176.         <span class="token operator">&amp;</span><span class="token keyword">self</span><span class="token punctuation">,</span>
    177. 

  177.         offset<span class="token punctuation">:</span> <span class="token keyword">usize</span><span class="token punctuation">,</span>
    178. 

  178.         len<span class="token punctuation">:</span> <span class="token keyword">usize</span><span class="token punctuation">,</span>
    179. 

  179.         buf<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token punctuation">[</span><span class="token keyword">u8</span><span class="token punctuation">]</span><span class="token punctuation">,</span>
    180. 

  180.         _data<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">mut</span> <span class="token class-name">FilePrivateData</span><span class="token punctuation">,</span>
    181. 

  181.     <span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token keyword">usize</span><span class="token punctuation">,</span> <span class="token class-name">SystemError</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
    182. 

  182.         <span class="token keyword">if</span> buf<span class="token punctuation">.</span><span class="token function">len</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">&lt;</span> len <span class="token punctuation">{</span>
    183. 

  183.             <span class="token keyword">return</span> <span class="token class-name">Err</span><span class="token punctuation">(</span><span class="token class-name">SystemError</span><span class="token punctuation">::</span><span class="token constant">EINVAL</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    184. 

  184.         <span class="token punctuation">}</span>
    185. 

  185. 

  186.         <span class="token comment">// 加锁</span>
    187. 

  187.         <span class="token keyword">let</span> <span class="token keyword">mut</span> inode<span class="token punctuation">:</span> <span class="token class-name">SpinLockGuard</span><span class="token operator">&lt;</span><span class="token class-name">RamFSInode</span><span class="token operator">&gt;</span> <span class="token operator">=</span> <span class="token keyword">self</span><span class="token punctuation">.</span><span class="token number">0</span><span class="token punctuation">.</span><span class="token function">lock</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    188. 

  188. 

  189.         <span class="token comment">// 检查当前inode是否为一个文件夹，如果是的话，就返回错误</span>
    190. 

  190.         <span class="token keyword">if</span> inode<span class="token punctuation">.</span>metadata<span class="token punctuation">.</span>file_type <span class="token operator">==</span> <span class="token class-name">FileType</span><span class="token punctuation">::</span><span class="token class-name">Dir</span> <span class="token punctuation">{</span>
    191. 

  191.             <span class="token keyword">return</span> <span class="token class-name">Err</span><span class="token punctuation">(</span><span class="token class-name">SystemError</span><span class="token punctuation">::</span><span class="token constant">EISDIR</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    192. 

  192.         <span class="token punctuation">}</span>
    193. 

  193. 

  194.         <span class="token comment">// LAB TODO BEGIN</span>
    195. 

  195. 

  196.         <span class="token comment">// LAB TODO END</span>
    197. 

  197. 

  198.         <span class="token keyword">return</span> <span class="token class-name">Ok</span><span class="token punctuation">(</span>len<span class="token punctuation">)</span><span class="token punctuation">;</span>
    199. 

  199.     <span class="token punctuation">}</span>
    200. 

  200. </code></pre></div><h2 id="实现-myramfs"><a href="#实现-myramfs" class="header-anchor">#</a> 实现 myramfs</h2> <blockquote><p>练习3：模仿 ramfs 实现 my_ramfs，并更正 ramfs</p></blockquote> <p>原 ramfs 其实是有点小问题的，需要在 my_ramfs 更正后再测试，具体如下：</p> <h3 id="open和close"><a href="#open和close" class="header-anchor">#</a> open和close</h3> <p>测试代码中打开文件调用的<code>open</code>函数，最终会进行系统调用，在 <strong>kernel/src/syscall</strong> 中，标志是<code>SYS_OPEN</code></p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token constant">SYS_OPEN</span> <span class="token operator">=&gt;</span> <span class="token punctuation">{</span>
    201. 

  201.     <span class="token keyword">let</span> path<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token class-name">CStr</span> <span class="token operator">=</span> <span class="token keyword">unsafe</span> <span class="token punctuation">{</span> <span class="token class-name">CStr</span><span class="token punctuation">::</span><span class="token function">from_ptr</span><span class="token punctuation">(</span>args<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span> <span class="token keyword">as</span> <span class="token operator">*</span><span class="token keyword">const</span> c_char<span class="token punctuation">)</span> <span class="token punctuation">}</span><span class="token punctuation">;</span>
    202. 

  202.     <span class="token keyword">let</span> path<span class="token punctuation">:</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token operator">&amp;</span><span class="token keyword">str</span><span class="token punctuation">,</span> <span class="token namespace">core<span class="token punctuation">::</span></span><span class="token keyword">str</span><span class="token punctuation">::</span><span class="token class-name">Utf8Error</span><span class="token operator">&gt;</span> <span class="token operator">=</span> path<span class="token punctuation">.</span><span class="token function">to_str</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    203. 

  203.     <span class="token keyword">let</span> res <span class="token operator">=</span> <span class="token keyword">if</span> path<span class="token punctuation">.</span><span class="token function">is_err</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    204. 

  204.         <span class="token class-name">Err</span><span class="token punctuation">(</span><span class="token class-name">SystemError</span><span class="token punctuation">::</span><span class="token constant">EINVAL</span><span class="token punctuation">)</span>
    205. 

  205.     <span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span>
    206. 

  206.         <span class="token keyword">let</span> path<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">str</span> <span class="token operator">=</span> path<span class="token punctuation">.</span><span class="token function">unwrap</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    207. 

  207.         <span class="token keyword">let</span> flags <span class="token operator">=</span> args<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
    208. 

  208.         <span class="token keyword">let</span> open_flags<span class="token punctuation">:</span> <span class="token class-name">FileMode</span> <span class="token operator">=</span> <span class="token class-name">FileMode</span><span class="token punctuation">::</span><span class="token function">from_bits_truncate</span><span class="token punctuation">(</span>flags <span class="token keyword">as</span> <span class="token keyword">u32</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    209. 

  209.         <span class="token keyword">Self</span><span class="token punctuation">::</span><span class="token function">open</span><span class="token punctuation">(</span>path<span class="token punctuation">,</span> open_flags<span class="token punctuation">)</span>
    210. 

  210.     <span class="token punctuation">}</span><span class="token punctuation">;</span>
    211. 

  211.     res
    212. 

  212. <span class="token punctuation">}</span>
    213. 

  213. </code></pre></div><p>检查文件路径正确后会调用同级目录下的 <strong>syscall.rs</strong> 中的 open 函数</p> <p>测试代码中的关闭文件调用<code>close</code>函数也和 open 类似，标志为<code>SYS_CLOSE</code>，然后调用 <strong>syscall.rs</strong> 中的 close 函数</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token constant">SYS_CLOSE</span> <span class="token operator">=&gt;</span> <span class="token punctuation">{</span>
    214. 

  214.     <span class="token keyword">let</span> fd <span class="token operator">=</span> args<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
    215. 

  215.     <span class="token keyword">Self</span><span class="token punctuation">::</span><span class="token function">close</span><span class="token punctuation">(</span>fd<span class="token punctuation">)</span>
    216. 

  216. <span class="token punctuation">}</span>
    217. 

  217. </code></pre></div><p>再看 <strong>kernel/vfs/mod.rs</strong> 的<code>IndexNode</code>接口中</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">pub</span> <span class="token keyword">trait</span> <span class="token type-definition class-name">IndexNode</span><span class="token punctuation">:</span> <span class="token class-name">Any</span> <span class="token operator">+</span> <span class="token class-name">Sync</span> <span class="token operator">+</span> <span class="token class-name">Send</span> <span class="token operator">+</span> <span class="token class-name">Debug</span> <span class="token punctuation">{</span>
    218. 

  218.    <span class="token comment">/// @brief 打开文件</span>
    219. 

  219.    <span class="token comment">/// @return 成功：Ok()</span>
    220. 

  220.    <span class="token comment">///         失败：Err(错误码)</span>
    221. 

  221.    <span class="token keyword">fn</span> <span class="token function-definition function">open</span><span class="token punctuation">(</span><span class="token operator">&amp;</span><span class="token keyword">self</span><span class="token punctuation">,</span> _data<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">mut</span> <span class="token class-name">FilePrivateData</span><span class="token punctuation">,</span> _mode<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token class-name">FileMode</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token class-name">SystemError</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
    222. 

  222.        <span class="token comment">// 若文件系统没有实现此方法，则返回“不支持”</span>
    223. 

  223.        <span class="token keyword">return</span> <span class="token class-name">Err</span><span class="token punctuation">(</span><span class="token class-name">SystemError</span><span class="token punctuation">::</span><span class="token constant">EOPNOTSUPP_OR_ENOTSUP</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    224. 

  224.    <span class="token punctuation">}</span>
    225. 

  225. 

  226.    <span class="token comment">/// @brief 关闭文件</span>
    227. 

  227.    <span class="token comment">/// @return 成功：Ok()</span>
    228. 

  228.    <span class="token comment">///         失败：Err(错误码)</span>
    229. 

  229.     <span class="token keyword">fn</span> <span class="token function-definition function">close</span><span class="token punctuation">(</span><span class="token operator">&amp;</span><span class="token keyword">self</span><span class="token punctuation">,</span> _data<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">mut</span> <span class="token class-name">FilePrivateData</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token class-name">SystemError</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
    230. 

  230.         <span class="token comment">// 若文件系统没有实现此方法，则返回“不支持”</span>
    231. 

  231.         <span class="token keyword">return</span> <span class="token class-name">Err</span><span class="token punctuation">(</span><span class="token class-name">SystemError</span><span class="token punctuation">::</span><span class="token constant">EOPNOTSUPP_OR_ENOTSUP</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    232. 

  232.     <span class="token punctuation">}</span>
    233. 

  233. <span class="token punctuation">}</span>
    234. 

  234. </code></pre></div><p>如果文件系统没有具体实现 open 和 close 函数，就返回不支持，所以这就是出错的原因</p> <p><strong>解决方式：</strong></p> <p>在我们模仿的 ramfs 文件系统里，添加 open 和 close 函数的具体实现，如下：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">fn</span> <span class="token function-definition function">open</span><span class="token punctuation">(</span><span class="token operator">&amp;</span><span class="token keyword">self</span><span class="token punctuation">,</span> _data<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">mut</span> <span class="token class-name">FilePrivateData</span><span class="token punctuation">,</span> _mode<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">super</span><span class="token module-declaration namespace"><span class="token punctuation">::</span>vfs<span class="token punctuation">::</span>file<span class="token punctuation">::</span></span><span class="token class-name">FileMode</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token class-name">SystemError</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
    235. 

  235.     <span class="token keyword">return</span> <span class="token class-name">Ok</span><span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    236. 

  236. <span class="token punctuation">}</span>
    237. 

  237. 

  238. <span class="token keyword">fn</span> <span class="token function-definition function">close</span><span class="token punctuation">(</span><span class="token operator">&amp;</span><span class="token keyword">self</span><span class="token punctuation">,</span> _data<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">mut</span> <span class="token class-name">FilePrivateData</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token class-name">SystemError</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
    239. 

  239.     <span class="token keyword">return</span> <span class="token class-name">Ok</span><span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    240. 

  240. <span class="token punctuation">}</span>
    241. 

  241. </code></pre></div><h3 id="fopen"><a href="#fopen" class="header-anchor">#</a> fopen</h3> <p>测试代码中我们用到了<code>fopen</code>来打开文件，第二个参数的&quot;w+&quot;的含义可以在 <strong>user/libs/libc/src/stdio.c</strong> 文件中查看，表示读写文件，并且如果文件不存在的话就创建这个文件</p> <p>fopen 的系统调用也是 SYS_OPEN ，但是和 open 的区别在于：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token comment">// 如果O_TRUNC，并且，打开模式包含O_RDWR或O_WRONLY，清空文件</span>
    242. 

  242. <span class="token keyword">if</span> mode<span class="token punctuation">.</span><span class="token function">contains</span><span class="token punctuation">(</span><span class="token class-name">FileMode</span><span class="token punctuation">::</span><span class="token constant">O_TRUNC</span><span class="token punctuation">)</span>
    243. 

  243.     <span class="token operator">&amp;&amp;</span> <span class="token punctuation">(</span>mode<span class="token punctuation">.</span><span class="token function">contains</span><span class="token punctuation">(</span><span class="token class-name">FileMode</span><span class="token punctuation">::</span><span class="token constant">O_RDWR</span><span class="token punctuation">)</span> <span class="token operator">||</span> mode<span class="token punctuation">.</span><span class="token function">contains</span><span class="token punctuation">(</span><span class="token class-name">FileMode</span><span class="token punctuation">::</span><span class="token constant">O_WRONLY</span><span class="token punctuation">)</span><span class="token punctuation">)</span>
    244. 

  244.     <span class="token operator">&amp;&amp;</span> file_type <span class="token operator">==</span> <span class="token class-name">FileType</span><span class="token punctuation">::</span><span class="token class-name">File</span>
    245. 

  245. <span class="token punctuation">{</span>
    246. 

  246.     inode<span class="token punctuation">.</span><span class="token function">truncate</span><span class="token punctuation">(</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token operator">?</span><span class="token punctuation">;</span>
    247. 

  247. <span class="token punctuation">}</span>
    248. 

  248. </code></pre></div><p>fopen 在满足条件的情况下会调用<code>truncate</code>函数，这个函数和 open 、close 一样，也是定义在 <strong>vfs/mod.rs</strong> 中的 IndexNode 接口中，但是没有具体实现，需要文件系统自己实现，如下：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token comment">/// @brief 截断当前inode到指定的长度。如果当前文件长度小于len,则不操作。</span>
    249. 

  249. <span class="token comment">///</span>
    250. 

  250. <span class="token comment">/// @param len 要被截断到的目标长度</span>
    251. 

  251. <span class="token keyword">fn</span> <span class="token function-definition function">truncate</span><span class="token punctuation">(</span><span class="token operator">&amp;</span><span class="token keyword">self</span><span class="token punctuation">,</span> _len<span class="token punctuation">:</span> <span class="token keyword">usize</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token class-name">SystemError</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
    252. 

  252.     <span class="token keyword">return</span> <span class="token class-name">Err</span><span class="token punctuation">(</span><span class="token class-name">SystemError</span><span class="token punctuation">::</span><span class="token constant">EOPNOTSUPP_OR_ENOTSUP</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    253. 

  253. <span class="token punctuation">}</span>
    254. 

  254. </code></pre></div><p><strong>解决方式：</strong></p> <p>所以需要在我们模仿的 ramfs 中，添加 truncate 的具体实现，如下：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">fn</span> <span class="token function-definition function">truncate</span><span class="token punctuation">(</span><span class="token operator">&amp;</span><span class="token keyword">self</span><span class="token punctuation">,</span> _len<span class="token punctuation">:</span> <span class="token keyword">usize</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span><span class="token operator">&lt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token class-name">SystemError</span><span class="token operator">&gt;</span> <span class="token punctuation">{</span>
    255. 

  255.     <span class="token keyword">let</span> <span class="token keyword">mut</span> inode <span class="token operator">=</span> <span class="token keyword">self</span><span class="token punctuation">.</span><span class="token number">0</span><span class="token punctuation">.</span><span class="token function">lock</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    256. 

  256.     <span class="token keyword">if</span> inode<span class="token punctuation">.</span>metadata<span class="token punctuation">.</span>file_type <span class="token operator">==</span> <span class="token class-name">FileType</span><span class="token punctuation">::</span><span class="token class-name">Dir</span> <span class="token punctuation">{</span>
    257. 

  257.         <span class="token keyword">return</span> <span class="token class-name">Err</span><span class="token punctuation">(</span><span class="token class-name">SystemError</span><span class="token punctuation">::</span><span class="token constant">EISDIR</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    258. 

  258.     <span class="token punctuation">}</span>
    259. 

  259.     inode<span class="token punctuation">.</span>data<span class="token punctuation">.</span><span class="token function">resize</span><span class="token punctuation">(</span>_len<span class="token punctuation">,</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    260. 

  260.     <span class="token keyword">return</span> <span class="token class-name">Ok</span><span class="token punctuation">(</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    261. 

  261. <span class="token punctuation">}</span>
    262. 

  262. </code></pre></div><h2 id="测试文件系统"><a href="#测试文件系统" class="header-anchor">#</a> 测试文件系统</h2> <p>测试我们模仿实现的 my_ramfs</p> <h3 id="创建测试文件夹"><a href="#创建测试文件夹" class="header-anchor">#</a> 创建测试文件夹</h3> <p>在 <strong>DragonOS/user/apps</strong> 目录下新建一个文件夹 <strong>my_test</strong></p> <h3 id="配置文件"><a href="#配置文件" class="header-anchor">#</a> 配置文件</h3> <h4 id="拷贝文件"><a href="#拷贝文件" class="header-anchor">#</a> 拷贝文件</h4> <p>找到 <strong>DragonOS/user/apps</strong> 目录下其他测试文件夹（例如：test_fstat）的两个文件：<strong>link.lds</strong> + <strong>Makefile</strong>，将这两个文件拷贝到我们新建的测试文件夹 <strong>my_test</strong> 中</p> <h4 id="更改makefile内容"><a href="#更改makefile内容" class="header-anchor">#</a> 更改Makefile内容</h4> <p>将 <strong>Makefile</strong> 中的测试目录名改回来，假设拷贝的是 test_fstat 目录的，则按如下修改：</p> <h4 id="test-fstat-makefile"><a href="#test-fstat-makefile" class="header-anchor">#</a> test_fstat/Makefile</h4> <div class="language-Makefile extra-class"><pre class="language-makefile"><code>CC<span class="token operator">=</span><span class="token variable">$</span><span class="token punctuation">(</span>DragonOS_GCC<span class="token punctuation">)</span>/x86_64-elf-gcc
    263. 

  263. LD<span class="token operator">=</span>ld
    264. 

  264. OBJCOPY<span class="token operator">=</span>objcopy
    265. 

  265. <span class="token comment"># 修改这里，把它改为你的relibc的sysroot路径</span>
    266. 

  266. RELIBC_OPT<span class="token operator">=</span><span class="token variable">$</span><span class="token punctuation">(</span>DADK_BUILD_CACHE_DIR_RELIBC_0_1_0<span class="token punctuation">)</span>
    267. 

  267. CFLAGS<span class="token operator">=</span>-I <span class="token variable">$</span><span class="token punctuation">(</span>RELIBC_OPT<span class="token punctuation">)</span>/<span class="token keyword">include</span> -D__dragonos__
    268. 

  268. 

  269. tmp_output_dir<span class="token operator">=</span><span class="token variable">$</span><span class="token punctuation">(</span>ROOT_PATH<span class="token punctuation">)</span>/bin/tmp/user
    270. 

  270. output_dir<span class="token operator">=</span><span class="token variable">$</span><span class="token punctuation">(</span>DADK_BUILD_CACHE_DIR_TEST_FSTAT_0_1_0<span class="token punctuation">)</span>
    271. 

  271. 

  272. LIBC_OBJS<span class="token operator">:=</span><span class="token variable">$</span><span class="token punctuation">(</span><span class="token function">shell</span> find <span class="token variable">$</span><span class="token punctuation">(</span>RELIBC_OPT<span class="token punctuation">)</span>/lib -name <span class="token string">&quot;*.o&quot;</span> <span class="token operator">|</span> sort <span class="token punctuation">)</span>
    273. 

  273. LIBC_OBJS<span class="token operator">+=</span><span class="token variable">$</span><span class="token punctuation">(</span>RELIBC_OPT<span class="token punctuation">)</span>/lib/libc.a
    274. 

  274. 

  275. <span class="token target symbol">all</span><span class="token punctuation">:</span> main.o
    276. 

  276. 	mkdir -p <span class="token variable">$</span><span class="token punctuation">(</span>tmp_output_dir<span class="token punctuation">)</span>
    277. 

  277. 	
    278. 

  278. 	<span class="token variable">$</span><span class="token punctuation">(</span>LD<span class="token punctuation">)</span> -b elf64-x86-64 -z muldefs -o <span class="token variable">$</span><span class="token punctuation">(</span>tmp_output_dir<span class="token punctuation">)</span>/test_fstat  <span class="token variable">$</span><span class="token punctuation">(</span><span class="token function">shell</span> find . -name <span class="token string">&quot;*.o&quot;</span><span class="token punctuation">)</span> <span class="token variable">$</span><span class="token punctuation">(</span>LIBC_OBJS<span class="token punctuation">)</span> -T link.lds
    279. 

  279. 

  280. 	<span class="token variable">$</span><span class="token punctuation">(</span>OBJCOPY<span class="token punctuation">)</span> -I elf64-x86-64 -R <span class="token string">&quot;.eh_frame&quot;</span> -R <span class="token string">&quot;.comment&quot;</span> -O elf64-x86-64 <span class="token variable">$</span><span class="token punctuation">(</span>tmp_output_dir<span class="token punctuation">)</span>/test_fstat <span class="token variable">$</span><span class="token punctuation">(</span>output_dir<span class="token punctuation">)</span>/test_fstat.elf
    281. 

  281. 	
    282. 

  282. 	mv <span class="token variable">$</span><span class="token punctuation">(</span>output_dir<span class="token punctuation">)</span>/test_fstat.elf <span class="token variable">$</span><span class="token punctuation">(</span>output_dir<span class="token punctuation">)</span>/test_fstat
    283. 

  283. <span class="token target symbol">main.o</span><span class="token punctuation">:</span> main.c
    284. 

  284. 	<span class="token variable">$</span><span class="token punctuation">(</span>CC<span class="token punctuation">)</span> <span class="token variable">$</span><span class="token punctuation">(</span>CFLAGS<span class="token punctuation">)</span> -c main.c  -o main.o
    285. 

  285. 

  286. <span class="token target symbol">clean</span><span class="token punctuation">:</span>
    287. 

  287. 	rm -f *.o
    288. 

  288. </code></pre></div><h4 id="my-test-makefile"><a href="#my-test-makefile" class="header-anchor">#</a> my_test/Makefile</h4> <div class="language-Makefile extra-class"><pre class="language-makefile"><code>CC<span class="token operator">=</span><span class="token variable">$</span><span class="token punctuation">(</span>DragonOS_GCC<span class="token punctuation">)</span>/x86_64-elf-gcc
    289. 

  289. LD<span class="token operator">=</span>ld
    290. 

  290. OBJCOPY<span class="token operator">=</span>objcopy
    291. 

  291. <span class="token comment"># 修改这里，把它改为你的relibc的sysroot路径</span>
    292. 

  292. RELIBC_OPT<span class="token operator">=</span><span class="token variable">$</span><span class="token punctuation">(</span>DADK_BUILD_CACHE_DIR_RELIBC_0_1_0<span class="token punctuation">)</span>
    293. 

  293. CFLAGS<span class="token operator">=</span>-I <span class="token variable">$</span><span class="token punctuation">(</span>RELIBC_OPT<span class="token punctuation">)</span>/<span class="token keyword">include</span> -D__dragonos__
    294. 

  294. 

  295. tmp_output_dir<span class="token operator">=</span><span class="token variable">$</span><span class="token punctuation">(</span>ROOT_PATH<span class="token punctuation">)</span>/bin/tmp/user
    296. 

  296. output_dir<span class="token operator">=</span><span class="token variable">$</span><span class="token punctuation">(</span>DADK_BUILD_CACHE_DIR_MY_TEST_0_1_0<span class="token punctuation">)</span>
    297. 

  297. 

  298. LIBC_OBJS<span class="token operator">:=</span><span class="token variable">$</span><span class="token punctuation">(</span><span class="token function">shell</span> find <span class="token variable">$</span><span class="token punctuation">(</span>RELIBC_OPT<span class="token punctuation">)</span>/lib -name <span class="token string">&quot;*.o&quot;</span> <span class="token operator">|</span> sort <span class="token punctuation">)</span>
    299. 

  299. LIBC_OBJS<span class="token operator">+=</span><span class="token variable">$</span><span class="token punctuation">(</span>RELIBC_OPT<span class="token punctuation">)</span>/lib/libc.a
    300. 

  300. 

  301. <span class="token target symbol">all</span><span class="token punctuation">:</span> main.o
    302. 

  302. 	mkdir -p <span class="token variable">$</span><span class="token punctuation">(</span>tmp_output_dir<span class="token punctuation">)</span>
    303. 

  303. 	
    304. 

  304. 	<span class="token variable">$</span><span class="token punctuation">(</span>LD<span class="token punctuation">)</span> -b elf64-x86-64 -z muldefs -o <span class="token variable">$</span><span class="token punctuation">(</span>tmp_output_dir<span class="token punctuation">)</span>/my_test  <span class="token variable">$</span><span class="token punctuation">(</span><span class="token function">shell</span> find . -name <span class="token string">&quot;*.o&quot;</span><span class="token punctuation">)</span> <span class="token variable">$</span><span class="token punctuation">(</span>LIBC_OBJS<span class="token punctuation">)</span> -T link.lds
    305. 

  305. 

  306. 	<span class="token variable">$</span><span class="token punctuation">(</span>OBJCOPY<span class="token punctuation">)</span> -I elf64-x86-64 -R <span class="token string">&quot;.eh_frame&quot;</span> -R <span class="token string">&quot;.comment&quot;</span> -O elf64-x86-64 <span class="token variable">$</span><span class="token punctuation">(</span>tmp_output_dir<span class="token punctuation">)</span>/my_test <span class="token variable">$</span><span class="token punctuation">(</span>output_dir<span class="token punctuation">)</span>/my_test.elf
    307. 

  307. 	
    308. 

  308. 	mv <span class="token variable">$</span><span class="token punctuation">(</span>output_dir<span class="token punctuation">)</span>/my_test.elf <span class="token variable">$</span><span class="token punctuation">(</span>output_dir<span class="token punctuation">)</span>/my_test
    309. 

  309. <span class="token target symbol">main.o</span><span class="token punctuation">:</span> main.c
    310. 

  310. 	<span class="token variable">$</span><span class="token punctuation">(</span>CC<span class="token punctuation">)</span> <span class="token variable">$</span><span class="token punctuation">(</span>CFLAGS<span class="token punctuation">)</span> -c main.c  -o main.o
    311. 

  311. 

  312. <span class="token target symbol">clean</span><span class="token punctuation">:</span>
    313. 

  313. 	rm -f *.o
    314. 

  314. </code></pre></div><p>将代码里的 <strong>test_fstat</strong> 改为 <strong>my_test</strong>（<strong>PS:</strong> 注意区分大小写）</p> <h2 id="配置dadk"><a href="#配置dadk" class="header-anchor">#</a> 配置dadk</h2> <h3 id="拷贝文件-2"><a href="#拷贝文件-2" class="header-anchor">#</a> 拷贝文件</h3> <p>在 <strong>DragonOS/user/dadk/config</strong> 目录下模仿其它文件新建一个文件 <strong>my_test-0.1.0.dadk</strong>（<strong>PS:</strong> 这里的my_test和我们在第一步创建的测试目录名相同），然后拷贝其他文件的内容到里面，比如拷贝 <strong>test_fstat-0.1.0.dadk</strong></p> <h3 id="更改dadk内容"><a href="#更改dadk内容" class="header-anchor">#</a> 更改dadk内容</h3> <p>还是和之前类似，按如下修改：</p> <h4 id="test-fstat-0-1-0-dadk"><a href="#test-fstat-0-1-0-dadk" class="header-anchor">#</a> <strong>test_fstat-0.1.0.dadk</strong></h4> <div class="language-dadk extra-class"><pre class="language-text"><code>{
    315. 

  315.   &quot;name&quot;: &quot;test_fstat&quot;,
    316. 

  316.   &quot;version&quot;: &quot;0.1.0&quot;,
    317. 

  317.   &quot;description&quot;: &quot;一个用来测试fstat能够正常运行的app&quot;,
    318. 

  318.   &quot;task_type&quot;: {
    319. 

  319.     &quot;BuildFromSource&quot;: {
    320. 

  320.       &quot;Local&quot;: {
    321. 

  321.         &quot;path&quot;: &quot;apps/test_fstat&quot;
    322. 

  322.       }
    323. 

  323.     }
    324. 

  324.   },
    325. 

  325. }
    326. 

  326. </code></pre></div><h4 id="my-test-0-1-0-dadk"><a href="#my-test-0-1-0-dadk" class="header-anchor">#</a> <strong>my_test-0.1.0.dadk</strong></h4> <div class="language-dadk extra-class"><pre class="language-text"><code>{
    327. 

  327.   &quot;name&quot;: &quot;my_test&quot;,
    328. 

  328.   &quot;version&quot;: &quot;0.1.0&quot;,
    329. 

  329.   &quot;description&quot;: &quot;一个用来测试ramfs能够正常运行的app&quot;,
    330. 

  330.   &quot;task_type&quot;: {
    331. 

  331.     &quot;BuildFromSource&quot;: {
    332. 

  332.       &quot;Local&quot;: {
    333. 

  333.         &quot;path&quot;: &quot;apps/my_test&quot;
    334. 

  334.       }
    335. 

  335.     }
    336. 

  336.   },
    337. 

  337. }
    338. 

  338. </code></pre></div><p>将代码里的 <strong>test_fstat</strong> 都改成 <strong>my_test</strong></p> <h2 id="挂载文件系统"><a href="#挂载文件系统" class="header-anchor">#</a> 挂载文件系统</h2> <p>将你要测试的文件系统挂载到我们的操作系统上面</p> <p>打开 <strong>DragonOS/kernel/src/filesystem/vfs/core.rs</strong> 文件</p> <h3 id="导入"><a href="#导入" class="header-anchor">#</a> 导入</h3> <p>导入你自己实现的文件系统，比如我这里是模仿ramfs写了一个my_ramfs，就按如下添加：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">use</span> <span class="token keyword">crate</span><span class="token punctuation">::</span><span class="token punctuation">{</span>
    339. 

  339.     <span class="token namespace">driver<span class="token punctuation">::</span>disk<span class="token punctuation">::</span>ahci<span class="token punctuation">::</span></span><span class="token punctuation">{</span><span class="token keyword">self</span><span class="token punctuation">}</span><span class="token punctuation">,</span>
    340. 

  340.     <span class="token namespace">filesystem<span class="token punctuation">::</span></span><span class="token punctuation">{</span>
    341. 

  341.         <span class="token namespace">devfs<span class="token punctuation">::</span></span><span class="token class-name">DevFS</span><span class="token punctuation">,</span>
    342. 

  342.         <span class="token namespace">fat<span class="token punctuation">::</span>fs<span class="token punctuation">::</span></span><span class="token class-name">FATFileSystem</span><span class="token punctuation">,</span>
    343. 

  343.         <span class="token namespace">procfs<span class="token punctuation">::</span></span><span class="token class-name">ProcFS</span><span class="token punctuation">,</span>
    344. 

  344.         <span class="token namespace">my_ramfs<span class="token punctuation">::</span></span><span class="token class-name">RamFS</span><span class="token punctuation">,</span>
    345. 

  345.         <span class="token namespace">sysfs<span class="token punctuation">::</span></span><span class="token class-name">SysFS</span><span class="token punctuation">,</span>
    346. 

  346.         <span class="token namespace">vfs<span class="token punctuation">::</span></span><span class="token punctuation">{</span><span class="token namespace">mount<span class="token punctuation">::</span></span><span class="token class-name">MountFS</span><span class="token punctuation">,</span> <span class="token class-name">FileSystem</span><span class="token punctuation">,</span> <span class="token class-name">FileType</span><span class="token punctuation">}</span><span class="token punctuation">,</span>
    347. 

  347.     <span class="token punctuation">}</span><span class="token punctuation">,</span>
    348. 

  348.     <span class="token namespace">include<span class="token punctuation">::</span>bindings<span class="token punctuation">::</span>bindings<span class="token punctuation">::</span></span><span class="token constant">PAGE_4K_SIZE</span><span class="token punctuation">,</span>
    349. 

  349.     kerror<span class="token punctuation">,</span> kinfo<span class="token punctuation">,</span>
    350. 

  350.     <span class="token namespace">syscall<span class="token punctuation">::</span></span><span class="token class-name">SystemError</span><span class="token punctuation">,</span>
    351. 

  351. <span class="token punctuation">}</span><span class="token punctuation">;</span>
    352. 

  352. </code></pre></div><h3 id="创建文件夹、实例并挂载"><a href="#创建文件夹、实例并挂载" class="header-anchor">#</a> 创建文件夹、实例并挂载</h3> <p>在<code>vfs_init</code>函数中：</p> <p>模仿其它文件系统创建当前准备测试的文件系统的文件夹，如下：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token comment">// 创建文件夹</span>
    353. 

  353. root_inode
    354. 

  354.     <span class="token punctuation">.</span><span class="token function">create</span><span class="token punctuation">(</span><span class="token string">&quot;proc&quot;</span><span class="token punctuation">,</span> <span class="token class-name">FileType</span><span class="token punctuation">::</span><span class="token class-name">Dir</span><span class="token punctuation">,</span> <span class="token number">0o777</span><span class="token punctuation">)</span>
    355. 

  355.     <span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;Failed to create /proc&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    356. 

  356. root_inode
    357. 

  357.     <span class="token punctuation">.</span><span class="token function">create</span><span class="token punctuation">(</span><span class="token string">&quot;dev&quot;</span><span class="token punctuation">,</span> <span class="token class-name">FileType</span><span class="token punctuation">::</span><span class="token class-name">Dir</span><span class="token punctuation">,</span> <span class="token number">0o777</span><span class="token punctuation">)</span>
    358. 

  358.     <span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;Failed to create /dev&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    359. 

  359. root_inode
    360. 

  360.     <span class="token punctuation">.</span><span class="token function">create</span><span class="token punctuation">(</span><span class="token string">&quot;sys&quot;</span><span class="token punctuation">,</span> <span class="token class-name">FileType</span><span class="token punctuation">::</span><span class="token class-name">Dir</span><span class="token punctuation">,</span> <span class="token number">0o777</span><span class="token punctuation">)</span>
    361. 

  361.     <span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;Failed to create /sys&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    362. 

  362. 

  363. <span class="token comment">// 添加至这里</span>
    364. 

  364. 

  365. root_inode
    366. 

  366.     <span class="token punctuation">.</span><span class="token function">create</span><span class="token punctuation">(</span><span class="token string">&quot;ram&quot;</span><span class="token punctuation">,</span> <span class="token class-name">FileType</span><span class="token punctuation">::</span><span class="token class-name">Dir</span><span class="token punctuation">,</span> <span class="token number">0o777</span><span class="token punctuation">)</span>
    367. 

  367.     <span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;Failed to create /ram&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    368. 

  368. </code></pre></div><p>紧接着在下面创建 ramfs 实例，并挂载，照样是模仿其它文件系统挂载，如下：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token comment">// 创建 sysfs 实例</span>
    369. 

  369. <span class="token keyword">let</span> sysfs<span class="token punctuation">:</span> <span class="token class-name">Arc</span><span class="token operator">&lt;</span><span class="token class-name">SysFS</span><span class="token operator">&gt;</span> <span class="token operator">=</span> <span class="token class-name">SysFS</span><span class="token punctuation">::</span><span class="token function">new</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    370. 

  370. <span class="token comment">// sysfs 挂载</span>
    371. 

  371. <span class="token keyword">let</span> _t <span class="token operator">=</span> root_inode
    372. 

  372.     <span class="token punctuation">.</span><span class="token function">find</span><span class="token punctuation">(</span><span class="token string">&quot;sys&quot;</span><span class="token punctuation">)</span>
    373. 

  373.     <span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;Cannot find /sys&quot;</span><span class="token punctuation">)</span>
    374. 

  374.     <span class="token punctuation">.</span><span class="token function">mount</span><span class="token punctuation">(</span>sysfs<span class="token punctuation">)</span>
    375. 

  375.     <span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;Failed to mount sysfs&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    376. 

  376. <span class="token macro property">kinfo!</span><span class="token punctuation">(</span><span class="token string">&quot;SysFS mounted.&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    377. 

  377. 

  378. <span class="token comment">// 添加至这里</span>
    379. 

  379. 

  380. <span class="token comment">// // 创建ramfs实例</span>
    381. 

  381. <span class="token keyword">let</span> ramfs<span class="token punctuation">:</span> <span class="token class-name">Arc</span><span class="token operator">&lt;</span><span class="token class-name">RamFS</span><span class="token operator">&gt;</span> <span class="token operator">=</span> <span class="token class-name">RamFS</span><span class="token punctuation">::</span><span class="token function">new</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    382. 

  382. <span class="token comment">// ramfs挂载</span>
    383. 

  383. <span class="token keyword">let</span> _t <span class="token operator">=</span> root_inode
    384. 

  384.     <span class="token punctuation">.</span><span class="token function">find</span><span class="token punctuation">(</span><span class="token string">&quot;ram&quot;</span><span class="token punctuation">)</span>
    385. 

  385.     <span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;Cannot find /ram&quot;</span><span class="token punctuation">)</span>
    386. 

  386.     <span class="token punctuation">.</span><span class="token function">mount</span><span class="token punctuation">(</span>ramfs<span class="token punctuation">)</span>
    387. 

  387.     <span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;Failed to mount ramfs.&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    388. 

  388. <span class="token macro property">kinfo!</span><span class="token punctuation">(</span><span class="token string">&quot;RamFS mounted.&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    389. 

  389. </code></pre></div><h3 id="迁移伪文件系统的inode"><a href="#迁移伪文件系统的inode" class="header-anchor">#</a> 迁移伪文件系统的inode</h3> <p>在 <strong>migrate_virtual_filesystem</strong> 函数中：</p> <h4 id="获取inode"><a href="#获取inode" class="header-anchor">#</a> 获取inode</h4> <p>模仿其它文件系统获取ramfs的inode，如下：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token comment">// ==== 在这里获取要被迁移的文件系统的inode ===</span>
    390. 

  390. <span class="token keyword">let</span> binding <span class="token operator">=</span> <span class="token constant">ROOT_INODE</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">find</span><span class="token punctuation">(</span><span class="token string">&quot;proc&quot;</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;ProcFS not mounted!&quot;</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">fs</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    391. 

  391. <span class="token keyword">let</span> proc<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token class-name">MountFS</span> <span class="token operator">=</span> binding<span class="token punctuation">.</span><span class="token function">as_any_ref</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">downcast_ref</span><span class="token punctuation">::</span><span class="token operator">&lt;</span><span class="token class-name">MountFS</span><span class="token operator">&gt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">unwrap</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    392. 

  392. <span class="token keyword">let</span> binding <span class="token operator">=</span> <span class="token constant">ROOT_INODE</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">find</span><span class="token punctuation">(</span><span class="token string">&quot;dev&quot;</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;DevFS not mounted!&quot;</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">fs</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    393. 

  393. <span class="token keyword">let</span> dev<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token class-name">MountFS</span> <span class="token operator">=</span> binding<span class="token punctuation">.</span><span class="token function">as_any_ref</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">downcast_ref</span><span class="token punctuation">::</span><span class="token operator">&lt;</span><span class="token class-name">MountFS</span><span class="token operator">&gt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">unwrap</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    394. 

  394. <span class="token keyword">let</span> binding <span class="token operator">=</span> <span class="token constant">ROOT_INODE</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">find</span><span class="token punctuation">(</span><span class="token string">&quot;sys&quot;</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;SysFs not mounted!&quot;</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">fs</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    395. 

  395. <span class="token keyword">let</span> sys<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token class-name">MountFS</span> <span class="token operator">=</span> binding<span class="token punctuation">.</span><span class="token function">as_any_ref</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">downcast_ref</span><span class="token punctuation">::</span><span class="token operator">&lt;</span><span class="token class-name">MountFS</span><span class="token operator">&gt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">unwrap</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    396. 

  396. 

  397. <span class="token comment">// 添加至这里</span>
    398. 

  398. 

  399. <span class="token keyword">let</span> binding <span class="token operator">=</span> <span class="token constant">ROOT_INODE</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">find</span><span class="token punctuation">(</span><span class="token string">&quot;ram&quot;</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">expect</span><span class="token punctuation">(</span><span class="token string">&quot;RamFs not mounted!&quot;</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">fs</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    400. 

  400. <span class="token keyword">let</span> ram<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token class-name">MountFS</span> <span class="token operator">=</span> binding<span class="token punctuation">.</span><span class="token function">as_any_ref</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">downcast_ref</span><span class="token punctuation">::</span><span class="token operator">&lt;</span><span class="token class-name">MountFS</span><span class="token operator">&gt;</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">.</span><span class="token function">unwrap</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    401. 

  401. </code></pre></div><h4 id="迁移到新的文件系统下"><a href="#迁移到新的文件系统下" class="header-anchor">#</a> 迁移到新的文件系统下</h4> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token comment">// 把上述文件系统,迁移到新的文件系统下</span>
    402. 

  402. <span class="token function">do_migrate</span><span class="token punctuation">(</span>new_root_inode<span class="token punctuation">.</span><span class="token function">clone</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token string">&quot;proc&quot;</span><span class="token punctuation">,</span> proc<span class="token punctuation">)</span><span class="token operator">?</span><span class="token punctuation">;</span>
    403. 

  403. <span class="token function">do_migrate</span><span class="token punctuation">(</span>new_root_inode<span class="token punctuation">.</span><span class="token function">clone</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token string">&quot;dev&quot;</span><span class="token punctuation">,</span> dev<span class="token punctuation">)</span><span class="token operator">?</span><span class="token punctuation">;</span>
    404. 

  404. <span class="token function">do_migrate</span><span class="token punctuation">(</span>new_root_inode<span class="token punctuation">.</span><span class="token function">clone</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token string">&quot;sys&quot;</span><span class="token punctuation">,</span> sys<span class="token punctuation">)</span><span class="token operator">?</span><span class="token punctuation">;</span>
    405. 

  405. 

  406. <span class="token comment">// 添加至这里</span>
    407. 

  407. 

  408. <span class="token function">do_migrate</span><span class="token punctuation">(</span>new_root_inode<span class="token punctuation">.</span><span class="token function">clone</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">,</span> <span class="token string">&quot;ram&quot;</span><span class="token punctuation">,</span> ram<span class="token punctuation">)</span><span class="token operator">?</span><span class="token punctuation">;</span>
    409. 

  409. </code></pre></div><h2 id="开始测试"><a href="#开始测试" class="header-anchor">#</a> 开始测试</h2> <p>至此，我们就可以开始测试文件系统了。</p> <p>在之前我们新建的测试文件夹 <strong>DragonOS/user/apps/my_test</strong> 目录下添加 <strong>main.c</strong> 文件，用来测试文件系统的开、关、读、写</p> <p>测试的过程中会出现一些问题，具体原因在上文的 <strong>ramfs的更正</strong> 中</p> <div class="language-c extra-class"><pre class="language-c"><code><span class="token macro property"><span class="token directive-hash">#</span><span class="token directive keyword">include</span><span class="token string">&lt;sys/types.h&gt;</span></span>
    410. 

  410. <span class="token macro property"><span class="token directive-hash">#</span><span class="token directive keyword">include</span><span class="token string">&lt;sys/stat.h&gt;</span></span>
    411. 

  411. <span class="token macro property"><span class="token directive-hash">#</span><span class="token directive keyword">include</span><span class="token string">&lt;fcntl.h&gt;</span></span>
    412. 

  412. <span class="token macro property"><span class="token directive-hash">#</span><span class="token directive keyword">include</span><span class="token string">&lt;unistd.h&gt;</span></span>
    413. 

  413. <span class="token macro property"><span class="token directive-hash">#</span><span class="token directive keyword">include</span><span class="token string">&lt;stdio.h&gt;</span></span>
    414. 

  414. 

  415. <span class="token keyword">int</span> <span class="token function">main</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
    416. 

  416.     <span class="token comment">//需要先创建文件夹</span>
    417. 

  417.     <span class="token keyword">int</span> check<span class="token operator">=</span><span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">;</span>
    418. 

  418.     check <span class="token operator">=</span> <span class="token function">mkdir</span><span class="token punctuation">(</span><span class="token string">&quot;/ram/test_0&quot;</span><span class="token punctuation">,</span><span class="token number">0777</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    419. 

  419.     <span class="token keyword">if</span><span class="token punctuation">(</span>check<span class="token operator">!=</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
    420. 

  420.         <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Cannot create dir: /ram/test_0\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    421. 

  421.         <span class="token keyword">return</span><span class="token punctuation">;</span>
    422. 

  422.     <span class="token punctuation">}</span>
    423. 

  423.     check<span class="token operator">=</span><span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">;</span>
    424. 

  424.     check <span class="token operator">=</span> <span class="token function">mkdir</span><span class="token punctuation">(</span><span class="token string">&quot;/ram/test_1&quot;</span><span class="token punctuation">,</span><span class="token number">0777</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    425. 

  425.     <span class="token keyword">if</span><span class="token punctuation">(</span>check<span class="token operator">!=</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
    426. 

  426.         <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Cannot create dir: /ram/test_1\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    427. 

  427.         <span class="token keyword">return</span><span class="token punctuation">;</span>
    428. 

  428.     <span class="token punctuation">}</span>
    429. 

  429. 

  430.     <span class="token comment">//测试open+close+write+read</span>
    431. 

  431.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Test open/close/write/read\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    432. 

  432.     <span class="token keyword">int</span> fd<span class="token operator">=</span><span class="token operator">-</span><span class="token number">1</span><span class="token punctuation">;</span>
    433. 

  433.     fd<span class="token operator">=</span><span class="token function">open</span><span class="token punctuation">(</span><span class="token string">&quot;/ram/test_0/file_0.txt&quot;</span><span class="token punctuation">,</span>O_WRONLY <span class="token operator">|</span> O_CREAT<span class="token punctuation">)</span><span class="token punctuation">;</span>
    434. 

  434.     <span class="token keyword">if</span><span class="token punctuation">(</span>fd<span class="token operator">&lt;</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
    435. 

  435.         <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Open file failed!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    436. 

  436.         <span class="token keyword">return</span><span class="token punctuation">;</span>
    437. 

  437.     <span class="token punctuation">}</span>
    438. 

  438.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;File opened successfully!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    439. 

  439.     <span class="token keyword">const</span> <span class="token keyword">char</span><span class="token operator">*</span> write_ptr <span class="token operator">=</span> <span class="token string">&quot;Write str here&quot;</span><span class="token punctuation">;</span>
    440. 

  440.     <span class="token function">write</span><span class="token punctuation">(</span>fd<span class="token punctuation">,</span>write_ptr<span class="token punctuation">,</span><span class="token function">strlen</span><span class="token punctuation">(</span>write_ptr<span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    441. 

  441.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Having written:%s\n&quot;</span><span class="token punctuation">,</span>write_ptr<span class="token punctuation">)</span><span class="token punctuation">;</span>
    442. 

  442.     <span class="token function">close</span><span class="token punctuation">(</span>fd<span class="token punctuation">)</span><span class="token punctuation">;</span>
    443. 

  443.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;File closed successfully!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    444. 

  444. 

  445.     <span class="token comment">//测试open+close+read</span>
    446. 

  446.     fd<span class="token operator">=</span><span class="token function">open</span><span class="token punctuation">(</span><span class="token string">&quot;/ram/test_0/file_0.txt&quot;</span><span class="token punctuation">,</span>O_WRONLY <span class="token operator">|</span> O_CREAT<span class="token punctuation">)</span><span class="token punctuation">;</span>
    447. 

  447.     <span class="token keyword">if</span><span class="token punctuation">(</span>fd<span class="token operator">&lt;</span><span class="token number">0</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
    448. 

  448.         <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Open file failed!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    449. 

  449.         <span class="token keyword">return</span><span class="token punctuation">;</span>
    450. 

  450.     <span class="token punctuation">}</span>
    451. 

  451.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;File opened successfully!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    452. 

  452.     <span class="token keyword">char</span><span class="token operator">*</span> buf<span class="token punctuation">[</span><span class="token number">64</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
    453. 

  453.     <span class="token function">read</span><span class="token punctuation">(</span>fd<span class="token punctuation">,</span>buf<span class="token punctuation">,</span><span class="token number">64</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    454. 

  454.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Having read:%s\n&quot;</span><span class="token punctuation">,</span>buf<span class="token punctuation">)</span><span class="token punctuation">;</span>
    455. 

  455.     <span class="token function">close</span><span class="token punctuation">(</span>fd<span class="token punctuation">)</span><span class="token punctuation">;</span>
    456. 

  456.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;File closed successfully!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    457. 

  457. 

  458.     <span class="token comment">//测试fopen+fclose+fputs</span>
    459. 

  459.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;\nTest fopen/fclose/fputs/fgets\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    460. 

  460.     FILE<span class="token operator">*</span> file <span class="token operator">=</span> <span class="token function">fopen</span><span class="token punctuation">(</span><span class="token string">&quot;/ram/test_1/file_0.txt&quot;</span><span class="token punctuation">,</span><span class="token string">&quot;w+&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    461. 

  461.     <span class="token keyword">if</span><span class="token punctuation">(</span>file <span class="token operator">==</span> <span class="token constant">NULL</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
    462. 

  462.         <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Fopen file failed!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    463. 

  463.         <span class="token keyword">return</span><span class="token punctuation">;</span>
    464. 

  464.     <span class="token punctuation">}</span>
    465. 

  465.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;File opened successfully!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    466. 

  466.     <span class="token keyword">const</span> <span class="token keyword">char</span><span class="token operator">*</span> fputs_ptr <span class="token operator">=</span> <span class="token string">&quot;Fputs str here&quot;</span><span class="token punctuation">;</span>
    467. 

  467.     <span class="token function">fputs</span><span class="token punctuation">(</span>fputs_ptr<span class="token punctuation">,</span>file<span class="token punctuation">)</span><span class="token punctuation">;</span>
    468. 

  468.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Having fput: %s\n&quot;</span><span class="token punctuation">,</span>fputs_ptr<span class="token punctuation">)</span><span class="token punctuation">;</span>
    469. 

  469.     <span class="token function">fclose</span><span class="token punctuation">(</span>file<span class="token punctuation">)</span><span class="token punctuation">;</span>
    470. 

  470.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;File closed successfully!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    471. 

  471. 

  472.     <span class="token comment">//测试fopen+fclose+fgets</span>
    473. 

  473.     file <span class="token operator">=</span> <span class="token function">fopen</span><span class="token punctuation">(</span><span class="token string">&quot;/ram/test_1/file_0.txt&quot;</span><span class="token punctuation">,</span><span class="token string">&quot;r+&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    474. 

  474.     <span class="token keyword">if</span><span class="token punctuation">(</span>file<span class="token operator">==</span><span class="token constant">NULL</span><span class="token punctuation">)</span><span class="token punctuation">{</span>
    475. 

  475.         <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Fopen file failed!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    476. 

  476.         <span class="token keyword">return</span><span class="token punctuation">;</span>
    477. 

  477.     <span class="token punctuation">}</span>
    478. 

  478.     <span class="token keyword">char</span><span class="token operator">*</span> buf1<span class="token punctuation">[</span><span class="token number">64</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
    479. 

  479.     <span class="token function">fgets</span><span class="token punctuation">(</span>buf1<span class="token punctuation">,</span><span class="token number">64</span><span class="token punctuation">,</span>file<span class="token punctuation">)</span><span class="token punctuation">;</span>
    480. 

  480.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;Having got: %s\n&quot;</span><span class="token punctuation">,</span>buf1<span class="token punctuation">)</span><span class="token punctuation">;</span>
    481. 

  481.     <span class="token function">fclose</span><span class="token punctuation">(</span>file<span class="token punctuation">)</span><span class="token punctuation">;</span>
    482. 

  482.     <span class="token function">printf</span><span class="token punctuation">(</span><span class="token string">&quot;File closed successfully!\n&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    483. 

  483. <span class="token punctuation">}</span>
    484. 

  484. </code></pre></div></div> <footer class="page-edit"><!----> <!----></footer> <!----> </main></div><div class="global-ui"></div></div>
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