📄 block_dev.c
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<!doctype html public "-//W3C//DTD HTML 3.2//EN"><html><head><title>Linux/fs/block_dev.c</title><meta http-equiv=Content-Type content="text/html; charset=gb2312"><base href="http://oldlinux.org/lxr/http/"></head><body bgcolor=white><div align=center> [<b><i>源代码浏览</i></b>] [<a href="diff/fs/block_dev.c">区别标定</a>] [<a href="ident">标识符搜索</a>] [<a href="search">文本搜索</a>] [<a href="find">文件搜索</a>]</div><h1 align=center> <a href="http:/"> OldLinux</a> <a href="http:blurb.html"> 交叉引用</a><br> <a href="source/">Linux</a>/<a href="source/fs/">fs</a>/<a href="source/fs/block_dev.c">block_dev.c</a></h1><div align=center> <b>版本:</b> [<a href="source/fs/block_dev.c?v=1.0">1.0</a>] [<a href="source/fs/block_dev.c?v=0.99.11">0.99.11</a>] [<a href="source/fs/block_dev.c?v=0.99">0.99</a>] [<a href="source/fs/block_dev.c?v=0.97">0.97</a>] [<a href="source/fs/block_dev.c?v=0.96a">0.96a</a>] [<a href="source/fs/block_dev.c?v=0.95">0.95</a>] [<a href="source/fs/block_dev.c?v=0.12">0.12</a>] [<b><i>0.11</i></b>] [<a href="source/fs/block_dev.c?v=0.01">0.01</a>] <br> <b>体系结构:</b> [<b><i>i386</i></b>] <br></div><hr><pre> <a name=L1 href="source/fs/block_dev.c#L1">1</a> <b><i>/*</i></b> <a name=L2 href="source/fs/block_dev.c#L2">2</a> <b><i> * linux/fs/block_dev.c</i></b> <a name=L3 href="source/fs/block_dev.c#L3">3</a> <b><i> *</i></b> <a name=L4 href="source/fs/block_dev.c#L4">4</a> <b><i> * (C) 1991 Linus Torvalds</i></b> <a name=L5 href="source/fs/block_dev.c#L5">5</a> <b><i> */</i></b> <a name=L6 href="source/fs/block_dev.c#L6">6</a> <a name=L7 href="source/fs/block_dev.c#L7">7</a> #include <errno.h> <a name=L8 href="source/fs/block_dev.c#L8">8</a> <a name=L9 href="source/fs/block_dev.c#L9">9</a> #include <linux/sched.h> <a name=L10 href="source/fs/block_dev.c#L10">10</a> #include <linux/kernel.h> <a name=L11 href="source/fs/block_dev.c#L11">11</a> #include <asm/segment.h> <a name=L12 href="source/fs/block_dev.c#L12">12</a> #include <asm/system.h> <a name=L13 href="source/fs/block_dev.c#L13">13</a> <a name=L14 href="source/fs/block_dev.c#L14">14</a> int <a href="ident?i=block_write">block_write</a>(int dev, long * <a href="ident?i=pos">pos</a>, char * <a href="ident?i=buf">buf</a>, int <a href="ident?i=count">count</a>) <a name=L15 href="source/fs/block_dev.c#L15">15</a> { <a name=L16 href="source/fs/block_dev.c#L16">16</a> int block = *<a href="ident?i=pos">pos</a> >> <a href="ident?i=BLOCK_SIZE_BITS">BLOCK_SIZE_BITS</a>; <a name=L17 href="source/fs/block_dev.c#L17">17</a> int offset = *<a href="ident?i=pos">pos</a> & (<a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>-1); <a name=L18 href="source/fs/block_dev.c#L18">18</a> int chars; <a name=L19 href="source/fs/block_dev.c#L19">19</a> int written = 0; <a name=L20 href="source/fs/block_dev.c#L20">20</a> struct <a href="ident?i=buffer_head">buffer_head</a> * bh; <a name=L21 href="source/fs/block_dev.c#L21">21</a> register char * p; <a name=L22 href="source/fs/block_dev.c#L22">22</a> <a name=L23 href="source/fs/block_dev.c#L23">23</a> while (<a href="ident?i=count">count</a>>0) { <a name=L24 href="source/fs/block_dev.c#L24">24</a> chars = <a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a> - offset; <a name=L25 href="source/fs/block_dev.c#L25">25</a> if (chars > <a href="ident?i=count">count</a>) <a name=L26 href="source/fs/block_dev.c#L26">26</a> chars=<a href="ident?i=count">count</a>; <a name=L27 href="source/fs/block_dev.c#L27">27</a> if (chars == <a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>) <a name=L28 href="source/fs/block_dev.c#L28">28</a> bh = <a href="ident?i=getblk">getblk</a>(dev,block); <a name=L29 href="source/fs/block_dev.c#L29">29</a> else <a name=L30 href="source/fs/block_dev.c#L30">30</a> bh = <a href="ident?i=breada">breada</a>(dev,block,block+1,block+2,-1); <a name=L31 href="source/fs/block_dev.c#L31">31</a> block++; <a name=L32 href="source/fs/block_dev.c#L32">32</a> if (!bh) <a name=L33 href="source/fs/block_dev.c#L33">33</a> return written?written:-<a href="ident?i=EIO">EIO</a>; <a name=L34 href="source/fs/block_dev.c#L34">34</a> p = offset + bh->b_data; <a name=L35 href="source/fs/block_dev.c#L35">35</a> offset = 0; <a name=L36 href="source/fs/block_dev.c#L36">36</a> *<a href="ident?i=pos">pos</a> += chars; <a name=L37 href="source/fs/block_dev.c#L37">37</a> written += chars; <a name=L38 href="source/fs/block_dev.c#L38">38</a> <a href="ident?i=count">count</a> -= chars; <a name=L39 href="source/fs/block_dev.c#L39">39</a> while (chars-->0) <a name=L40 href="source/fs/block_dev.c#L40">40</a> *(p++) = <a href="ident?i=get_fs_byte">get_fs_byte</a>(<a href="ident?i=buf">buf</a>++); <a name=L41 href="source/fs/block_dev.c#L41">41</a> bh->b_dirt = 1; <a name=L42 href="source/fs/block_dev.c#L42">42</a> <a href="ident?i=brelse">brelse</a>(bh); <a name=L43 href="source/fs/block_dev.c#L43">43</a> } <a name=L44 href="source/fs/block_dev.c#L44">44</a> return written; <a name=L45 href="source/fs/block_dev.c#L45">45</a> } <a name=L46 href="source/fs/block_dev.c#L46">46</a> <a name=L47 href="source/fs/block_dev.c#L47">47</a> int <a href="ident?i=block_read">block_read</a>(int dev, unsigned long * <a href="ident?i=pos">pos</a>, char * <a href="ident?i=buf">buf</a>, int <a href="ident?i=count">count</a>) <a name=L48 href="source/fs/block_dev.c#L48">48</a> { <a name=L49 href="source/fs/block_dev.c#L49">49</a> int block = *<a href="ident?i=pos">pos</a> >> <a href="ident?i=BLOCK_SIZE_BITS">BLOCK_SIZE_BITS</a>; <a name=L50 href="source/fs/block_dev.c#L50">50</a> int offset = *<a href="ident?i=pos">pos</a> & (<a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>-1); <a name=L51 href="source/fs/block_dev.c#L51">51</a> int chars; <a name=L52 href="source/fs/block_dev.c#L52">52</a> int <a href="ident?i=read">read</a> = 0; <a name=L53 href="source/fs/block_dev.c#L53">53</a> struct <a href="ident?i=buffer_head">buffer_head</a> * bh; <a name=L54 href="source/fs/block_dev.c#L54">54</a> register char * p; <a name=L55 href="source/fs/block_dev.c#L55">55</a> <a name=L56 href="source/fs/block_dev.c#L56">56</a> while (<a href="ident?i=count">count</a>>0) { <a name=L57 href="source/fs/block_dev.c#L57">57</a> chars = <a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>-offset; <a name=L58 href="source/fs/block_dev.c#L58">58</a> if (chars > <a href="ident?i=count">count</a>) <a name=L59 href="source/fs/block_dev.c#L59">59</a> chars = <a href="ident?i=count">count</a>; <a name=L60 href="source/fs/block_dev.c#L60">60</a> if (!(bh = <a href="ident?i=breada">breada</a>(dev,block,block+1,block+2,-1))) <a name=L61 href="source/fs/block_dev.c#L61">61</a> return <a href="ident?i=read">read</a>?<a href="ident?i=read">read</a>:-<a href="ident?i=EIO">EIO</a>; <a name=L62 href="source/fs/block_dev.c#L62">62</a> block++; <a name=L63 href="source/fs/block_dev.c#L63">63</a> p = offset + bh->b_data; <a name=L64 href="source/fs/block_dev.c#L64">64</a> offset = 0; <a name=L65 href="source/fs/block_dev.c#L65">65</a> *<a href="ident?i=pos">pos</a> += chars; <a name=L66 href="source/fs/block_dev.c#L66">66</a> <a href="ident?i=read">read</a> += chars; <a name=L67 href="source/fs/block_dev.c#L67">67</a> <a href="ident?i=count">count</a> -= chars; <a name=L68 href="source/fs/block_dev.c#L68">68</a> while (chars-->0) <a name=L69 href="source/fs/block_dev.c#L69">69</a> <a href="ident?i=put_fs_byte">put_fs_byte</a>(*(p++),<a href="ident?i=buf">buf</a>++); <a name=L70 href="source/fs/block_dev.c#L70">70</a> <a href="ident?i=brelse">brelse</a>(bh); <a name=L71 href="source/fs/block_dev.c#L71">71</a> } <a name=L72 href="source/fs/block_dev.c#L72">72</a> return <a href="ident?i=read">read</a>; <a name=L73 href="source/fs/block_dev.c#L73">73</a> } <a name=L74 href="source/fs/block_dev.c#L74">74</a> </pre><hr><div align=center> [<b><i>源代码浏览</i></b>] [<a href="diff/fs/block_dev.c">区别标定</a>] [<a href="ident">标识符搜索</a>] [<a href="search">文本搜索</a>] [<a href="find">文件搜索</a>] </div><hr>本网页由 <a href="http:blurb.html">LXR引擎</a> 自动生成.<br></html>⌨️ 快捷键说明
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