namei.c

linux0.11 version(301k)

<a name=L106 href="source/fs/namei.c#L106">106</a> #endif
<a name=L107 href="source/fs/namei.c#L107">107</a>         entries = (*dir)-&gt;i_size / (sizeof (struct <a href="ident?i=dir_entry">dir_entry</a>));
<a name=L108 href="source/fs/namei.c#L108">108</a>         *res_dir = <a href="ident?i=NULL">NULL</a>;
<a name=L109 href="source/fs/namei.c#L109">109</a>         if (!namelen)
<a name=L110 href="source/fs/namei.c#L110">110</a>                 return <a href="ident?i=NULL">NULL</a>;
<a name=L111 href="source/fs/namei.c#L111">111</a> <b><i>/* check for '..', as we might have to do some "magic" for it */</i></b>
<a name=L112 href="source/fs/namei.c#L112">112</a>         if (namelen==2 &amp;&amp; <a href="ident?i=get_fs_byte">get_fs_byte</a>(name)==<i>'.'</i> &amp;&amp; <a href="ident?i=get_fs_byte">get_fs_byte</a>(name+1)==<i>'.'</i>) {
<a name=L113 href="source/fs/namei.c#L113">113</a> <b><i>/* '..' in a pseudo-root results in a faked '.' (just change namelen) */</i></b>
<a name=L114 href="source/fs/namei.c#L114">114</a>                 if ((*dir) == <a href="ident?i=current">current</a>-&gt;root)
<a name=L115 href="source/fs/namei.c#L115">115</a>                         namelen=1;
<a name=L116 href="source/fs/namei.c#L116">116</a>                 else if ((*dir)-&gt;i_num == <a href="ident?i=ROOT_INO">ROOT_INO</a>) {
<a name=L117 href="source/fs/namei.c#L117">117</a> <b><i>/* '..' over a mount-point results in 'dir' being exchanged for the mounted</i></b>
<a name=L118 href="source/fs/namei.c#L118">118</a> <b><i>   directory-inode. NOTE! We set mounted, so that we can iput the new dir */</i></b>
<a name=L119 href="source/fs/namei.c#L119">119</a>                         sb=<a href="ident?i=get_super">get_super</a>((*dir)-&gt;i_dev);
<a name=L120 href="source/fs/namei.c#L120">120</a>                         if (sb-&gt;s_imount) {
<a name=L121 href="source/fs/namei.c#L121">121</a>                                 <a href="ident?i=iput">iput</a>(*dir);
<a name=L122 href="source/fs/namei.c#L122">122</a>                                 (*dir)=sb-&gt;s_imount;
<a name=L123 href="source/fs/namei.c#L123">123</a>                                 (*dir)-&gt;i_count++;
<a name=L124 href="source/fs/namei.c#L124">124</a>                         }
<a name=L125 href="source/fs/namei.c#L125">125</a>                 }
<a name=L126 href="source/fs/namei.c#L126">126</a>         }
<a name=L127 href="source/fs/namei.c#L127">127</a>         if (!(block = (*dir)-&gt;i_zone[0]))
<a name=L128 href="source/fs/namei.c#L128">128</a>                 return <a href="ident?i=NULL">NULL</a>;
<a name=L129 href="source/fs/namei.c#L129">129</a>         if (!(bh = <a href="ident?i=bread">bread</a>((*dir)-&gt;i_dev,block)))
<a name=L130 href="source/fs/namei.c#L130">130</a>                 return <a href="ident?i=NULL">NULL</a>;
<a name=L131 href="source/fs/namei.c#L131">131</a>         i = 0;
<a name=L132 href="source/fs/namei.c#L132">132</a>         de = (struct <a href="ident?i=dir_entry">dir_entry</a> *) bh-&gt;b_data;
<a name=L133 href="source/fs/namei.c#L133">133</a>         while (i &lt; entries) {
<a name=L134 href="source/fs/namei.c#L134">134</a>                 if ((char *)de &gt;= <a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>+bh-&gt;b_data) {
<a name=L135 href="source/fs/namei.c#L135">135</a>                         <a href="ident?i=brelse">brelse</a>(bh);
<a name=L136 href="source/fs/namei.c#L136">136</a>                         bh = <a href="ident?i=NULL">NULL</a>;
<a name=L137 href="source/fs/namei.c#L137">137</a>                         if (!(block = <a href="ident?i=bmap">bmap</a>(*dir,i/<a href="ident?i=DIR_ENTRIES_PER_BLOCK">DIR_ENTRIES_PER_BLOCK</a>)) ||
<a name=L138 href="source/fs/namei.c#L138">138</a>                             !(bh = <a href="ident?i=bread">bread</a>((*dir)-&gt;i_dev,block))) {
<a name=L139 href="source/fs/namei.c#L139">139</a>                                 i += <a href="ident?i=DIR_ENTRIES_PER_BLOCK">DIR_ENTRIES_PER_BLOCK</a>;
<a name=L140 href="source/fs/namei.c#L140">140</a>                                 continue;
<a name=L141 href="source/fs/namei.c#L141">141</a>                         }
<a name=L142 href="source/fs/namei.c#L142">142</a>                         de = (struct <a href="ident?i=dir_entry">dir_entry</a> *) bh-&gt;b_data;
<a name=L143 href="source/fs/namei.c#L143">143</a>                 }
<a name=L144 href="source/fs/namei.c#L144">144</a>                 if (<a href="ident?i=match">match</a>(namelen,name,de)) {
<a name=L145 href="source/fs/namei.c#L145">145</a>                         *res_dir = de;
<a name=L146 href="source/fs/namei.c#L146">146</a>                         return bh;
<a name=L147 href="source/fs/namei.c#L147">147</a>                 }
<a name=L148 href="source/fs/namei.c#L148">148</a>                 de++;
<a name=L149 href="source/fs/namei.c#L149">149</a>                 i++;
<a name=L150 href="source/fs/namei.c#L150">150</a>         }
<a name=L151 href="source/fs/namei.c#L151">151</a>         <a href="ident?i=brelse">brelse</a>(bh);
<a name=L152 href="source/fs/namei.c#L152">152</a>         return <a href="ident?i=NULL">NULL</a>;
<a name=L153 href="source/fs/namei.c#L153">153</a> }
<a name=L154 href="source/fs/namei.c#L154">154</a> 
<a name=L155 href="source/fs/namei.c#L155">155</a> <b><i>/*</i></b>
<a name=L156 href="source/fs/namei.c#L156">156</a> <b><i> *      add_entry()</i></b>
<a name=L157 href="source/fs/namei.c#L157">157</a> <b><i> *</i></b>
<a name=L158 href="source/fs/namei.c#L158">158</a> <b><i> * adds a file entry to the specified directory, using the same</i></b>
<a name=L159 href="source/fs/namei.c#L159">159</a> <b><i> * semantics as find_entry(). It returns NULL if it failed.</i></b>
<a name=L160 href="source/fs/namei.c#L160">160</a> <b><i> *</i></b>
<a name=L161 href="source/fs/namei.c#L161">161</a> <b><i> * NOTE!! The inode part of 'de' is left at 0 - which means you</i></b>
<a name=L162 href="source/fs/namei.c#L162">162</a> <b><i> * may not sleep between calling this and putting something into</i></b>
<a name=L163 href="source/fs/namei.c#L163">163</a> <b><i> * the entry, as someone else might have used it while you slept.</i></b>
<a name=L164 href="source/fs/namei.c#L164">164</a> <b><i> */</i></b>
<a name=L165 href="source/fs/namei.c#L165">165</a> static struct <a href="ident?i=buffer_head">buffer_head</a> * <a href="ident?i=add_entry">add_entry</a>(struct <a href="ident?i=m_inode">m_inode</a> * dir,
<a name=L166 href="source/fs/namei.c#L166">166</a>         const char * name, int namelen, struct <a href="ident?i=dir_entry">dir_entry</a> ** res_dir)
<a name=L167 href="source/fs/namei.c#L167">167</a> {
<a name=L168 href="source/fs/namei.c#L168">168</a>         int block,i;
<a name=L169 href="source/fs/namei.c#L169">169</a>         struct <a href="ident?i=buffer_head">buffer_head</a> * bh;
<a name=L170 href="source/fs/namei.c#L170">170</a>         struct <a href="ident?i=dir_entry">dir_entry</a> * de;
<a name=L171 href="source/fs/namei.c#L171">171</a> 
<a name=L172 href="source/fs/namei.c#L172">172</a>         *res_dir = <a href="ident?i=NULL">NULL</a>;
<a name=L173 href="source/fs/namei.c#L173">173</a> #ifdef NO_TRUNCATE
<a name=L174 href="source/fs/namei.c#L174">174</a>         if (namelen &gt; <a href="ident?i=NAME_LEN">NAME_LEN</a>)
<a name=L175 href="source/fs/namei.c#L175">175</a>                 return <a href="ident?i=NULL">NULL</a>;
<a name=L176 href="source/fs/namei.c#L176">176</a> #else
<a name=L177 href="source/fs/namei.c#L177">177</a>         if (namelen &gt; <a href="ident?i=NAME_LEN">NAME_LEN</a>)
<a name=L178 href="source/fs/namei.c#L178">178</a>                 namelen = <a href="ident?i=NAME_LEN">NAME_LEN</a>;
<a name=L179 href="source/fs/namei.c#L179">179</a> #endif
<a name=L180 href="source/fs/namei.c#L180">180</a>         if (!namelen)
<a name=L181 href="source/fs/namei.c#L181">181</a>                 return <a href="ident?i=NULL">NULL</a>;
<a name=L182 href="source/fs/namei.c#L182">182</a>         if (!(block = dir-&gt;i_zone[0]))
<a name=L183 href="source/fs/namei.c#L183">183</a>                 return <a href="ident?i=NULL">NULL</a>;
<a name=L184 href="source/fs/namei.c#L184">184</a>         if (!(bh = <a href="ident?i=bread">bread</a>(dir-&gt;i_dev,block)))
<a name=L185 href="source/fs/namei.c#L185">185</a>                 return <a href="ident?i=NULL">NULL</a>;
<a name=L186 href="source/fs/namei.c#L186">186</a>         i = 0;
<a name=L187 href="source/fs/namei.c#L187">187</a>         de = (struct <a href="ident?i=dir_entry">dir_entry</a> *) bh-&gt;b_data;
<a name=L188 href="source/fs/namei.c#L188">188</a>         while (1) {
<a name=L189 href="source/fs/namei.c#L189">189</a>                 if ((char *)de &gt;= <a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>+bh-&gt;b_data) {
<a name=L190 href="source/fs/namei.c#L190">190</a>                         <a href="ident?i=brelse">brelse</a>(bh);
<a name=L191 href="source/fs/namei.c#L191">191</a>                         bh = <a href="ident?i=NULL">NULL</a>;
<a name=L192 href="source/fs/namei.c#L192">192</a>                         block = <a href="ident?i=create_block">create_block</a>(dir,i/<a href="ident?i=DIR_ENTRIES_PER_BLOCK">DIR_ENTRIES_PER_BLOCK</a>);
<a name=L193 href="source/fs/namei.c#L193">193</a>                         if (!block)
<a name=L194 href="source/fs/namei.c#L194">194</a>                                 return <a href="ident?i=NULL">NULL</a>;
<a name=L195 href="source/fs/namei.c#L195">195</a>                         if (!(bh = <a href="ident?i=bread">bread</a>(dir-&gt;i_dev,block))) {
<a name=L196 href="source/fs/namei.c#L196">196</a>                                 i += <a href="ident?i=DIR_ENTRIES_PER_BLOCK">DIR_ENTRIES_PER_BLOCK</a>;
<a name=L197 href="source/fs/namei.c#L197">197</a>                                 continue;
<a name=L198 href="source/fs/namei.c#L198">198</a>                         }
<a name=L199 href="source/fs/namei.c#L199">199</a>                         de = (struct <a href="ident?i=dir_entry">dir_entry</a> *) bh-&gt;b_data;
<a name=L200 href="source/fs/namei.c#L200">200</a>                 }
<a name=L201 href="source/fs/namei.c#L201">201</a>                 if (i*sizeof(struct <a href="ident?i=dir_entry">dir_entry</a>) &gt;= dir-&gt;i_size) {
<a name=L202 href="source/fs/namei.c#L202">202</a>                         de-&gt;inode=0;
<a name=L203 href="source/fs/namei.c#L203">203</a>                         dir-&gt;i_size = (i+1)*sizeof(struct <a href="ident?i=dir_entry">dir_entry</a>);
<a name=L204 href="source/fs/namei.c#L204">204</a>                         dir-&gt;i_dirt = 1;
<a name=L205 href="source/fs/namei.c#L205">205</a>                         dir-&gt;i_ctime = <a href="ident?i=CURRENT_TIME">CURRENT_TIME</a>;
<a name=L206 href="source/fs/namei.c#L206">206</a>                 }
<a name=L207 href="source/fs/namei.c#L207">207</a>                 if (!de-&gt;inode) {
<a name=L208 href="source/fs/namei.c#L208">208</a>                         dir-&gt;i_mtime = <a href="ident?i=CURRENT_TIME">CURRENT_TIME</a>;
<a name=L209 href="source/fs/namei.c#L209">209</a>                         for (i=0; i &lt; <a href="ident?i=NAME_LEN">NAME_LEN</a> ; i++)
<a name=L210 href="source/fs/namei.c#L210">210</a>                                 de-&gt;name[i]=(i&lt;namelen)?<a href="ident?i=get_fs_byte">get_fs_byte</a>(name+i):0;
<a name=L211 href="source/fs/namei.c#L211">211</a>                         bh-&gt;b_dirt = 1;
<a name=L212 href="source/fs/namei.c#L212">212</a>                         *res_dir = de;
<a name=L213 href="source/fs/namei.c#L213">213</a>                         return bh;
<a name=L214 href="source/fs/namei.c#L214">214</a>                 }
<a name=L215 href="source/fs/namei.c#L215">215</a>                 de++;
<a name=L216 href="source/fs/namei.c#L216">216</a>                 i++;
<a name=L217 href="source/fs/namei.c#L217">217</a>         }
<a name=L218 href="source/fs/namei.c#L218">218</a>         <a href="ident?i=brelse">brelse</a>(bh);
<a name=L219 href="source/fs/namei.c#L219">219</a>         return <a href="ident?i=NULL">NULL</a>;
<a name=L220 href="source/fs/namei.c#L220">220</a> }
<a name=L221 href="source/fs/namei.c#L221">221</a> 
<a name=L222 href="source/fs/namei.c#L222">222</a> <b><i>/*</i></b>
<a name=L223 href="source/fs/namei.c#L223">223</a> <b><i> *      get_dir()</i></b>
<a name=L224 href="source/fs/namei.c#L224">224</a> <b><i> *</i></b>
<a name=L225 href="source/fs/namei.c#L225">225</a> <b><i> * Getdir traverses the pathname until it hits the topmost directory.</i></b>
<a name=L226 href="source/fs/namei.c#L226">226</a> <b><i> * It returns NULL on failure.</i></b>
<a name=L227 href="source/fs/namei.c#L227">227</a> <b><i> */</i></b>
<a name=L228 href="source/fs/namei.c#L228">228</a> static struct <a href="ident?i=m_inode">m_inode</a> * <a href="ident?i=get_dir">get_dir</a>(const char * pathname)
<a name=L229 href="source/fs/namei.c#L229">229</a> {
<a name=L230 href="source/fs/namei.c#L230">230</a>         char c;
<a name=L231 href="source/fs/namei.c#L231">231</a>         const char * thisname;
<a name=L232 href="source/fs/namei.c#L232">232</a>         struct <a href="ident?i=m_inode">m_inode</a> * inode;
<a name=L233 href="source/fs/namei.c#L233">233</a>         struct <a href="ident?i=buffer_head">buffer_head</a> * bh;
<a name=L234 href="source/fs/namei.c#L234">234</a>         int namelen,inr,idev;
<a name=L235 href="source/fs/namei.c#L235">235</a>         struct <a href="ident?i=dir_entry">dir_entry</a> * de;
<a name=L236 href="source/fs/namei.c#L236">236</a> 
<a name=L237 href="source/fs/namei.c#L237">237</a>         if (!<a href="ident?i=current">current</a>-&gt;root || !<a href="ident?i=current">current</a>-&gt;root-&gt;i_count)
<a name=L238 href="source/fs/namei.c#L238">238</a>                 <a href="ident?i=panic">panic</a>(<i>"No root inode"</i>);
<a name=L239 href="source/fs/namei.c#L239">239</a>         if (!<a href="ident?i=current">current</a>-&gt;pwd || !<a href="ident?i=current">current</a>-&gt;pwd-&gt;i_count)
<a name=L240 href="source/fs/namei.c#L240">240</a>                 <a href="ident?i=panic">panic</a>(<i>"No cwd inode"</i>);
<a name=L241 href="source/fs/namei.c#L241">241</a>         if ((c=<a href="ident?i=get_fs_byte">get_fs_byte</a>(pathname))==<i>'/'</i>) {