📄 file_dev.c
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<!doctype html public "-//W3C//DTD HTML 3.2//EN"><html><head><title>Linux/fs/file_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/file_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/file_dev.c">file_dev.c</a></h1><div align=center> <b>版本:</b> [<a href="source/fs/file_dev.c?v=1.0">1.0</a>] [<a href="source/fs/file_dev.c?v=0.99.11">0.99.11</a>] [<a href="source/fs/file_dev.c?v=0.99">0.99</a>] [<a href="source/fs/file_dev.c?v=0.97">0.97</a>] [<a href="source/fs/file_dev.c?v=0.96a">0.96a</a>] [<a href="source/fs/file_dev.c?v=0.95">0.95</a>] [<a href="source/fs/file_dev.c?v=0.12">0.12</a>] [<b><i>0.11</i></b>] [<a href="source/fs/file_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/file_dev.c#L1">1</a> <b><i>/*</i></b> <a name=L2 href="source/fs/file_dev.c#L2">2</a> <b><i> * linux/fs/file_dev.c</i></b> <a name=L3 href="source/fs/file_dev.c#L3">3</a> <b><i> *</i></b> <a name=L4 href="source/fs/file_dev.c#L4">4</a> <b><i> * (C) 1991 Linus Torvalds</i></b> <a name=L5 href="source/fs/file_dev.c#L5">5</a> <b><i> */</i></b> <a name=L6 href="source/fs/file_dev.c#L6">6</a> <a name=L7 href="source/fs/file_dev.c#L7">7</a> #include <errno.h> <a name=L8 href="source/fs/file_dev.c#L8">8</a> #include <fcntl.h> <a name=L9 href="source/fs/file_dev.c#L9">9</a> <a name=L10 href="source/fs/file_dev.c#L10">10</a> #include <linux/sched.h> <a name=L11 href="source/fs/file_dev.c#L11">11</a> #include <linux/kernel.h> <a name=L12 href="source/fs/file_dev.c#L12">12</a> #include <asm/segment.h> <a name=L13 href="source/fs/file_dev.c#L13">13</a> <a name=L14 href="source/fs/file_dev.c#L14">14</a> #define <a href="ident?i=MIN">MIN</a>(a,b) (((a)<(b))?(a):(b)) <a name=L15 href="source/fs/file_dev.c#L15">15</a> #define <a href="ident?i=MAX">MAX</a>(a,b) (((a)>(b))?(a):(b)) <a name=L16 href="source/fs/file_dev.c#L16">16</a> <a name=L17 href="source/fs/file_dev.c#L17">17</a> int <a href="ident?i=file_read">file_read</a>(struct <a href="ident?i=m_inode">m_inode</a> * inode, struct <a href="ident?i=file">file</a> * filp, char * <a href="ident?i=buf">buf</a>, int <a href="ident?i=count">count</a>) <a name=L18 href="source/fs/file_dev.c#L18">18</a> { <a name=L19 href="source/fs/file_dev.c#L19">19</a> int left,chars,nr; <a name=L20 href="source/fs/file_dev.c#L20">20</a> struct <a href="ident?i=buffer_head">buffer_head</a> * bh; <a name=L21 href="source/fs/file_dev.c#L21">21</a> <a name=L22 href="source/fs/file_dev.c#L22">22</a> if ((left=<a href="ident?i=count">count</a>)<=0) <a name=L23 href="source/fs/file_dev.c#L23">23</a> return 0; <a name=L24 href="source/fs/file_dev.c#L24">24</a> while (left) { <a name=L25 href="source/fs/file_dev.c#L25">25</a> if (nr = <a href="ident?i=bmap">bmap</a>(inode,(filp->f_pos)/<a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>)) { <a name=L26 href="source/fs/file_dev.c#L26">26</a> if (!(bh=<a href="ident?i=bread">bread</a>(inode->i_dev,nr))) <a name=L27 href="source/fs/file_dev.c#L27">27</a> break; <a name=L28 href="source/fs/file_dev.c#L28">28</a> } else <a name=L29 href="source/fs/file_dev.c#L29">29</a> bh = <a href="ident?i=NULL">NULL</a>; <a name=L30 href="source/fs/file_dev.c#L30">30</a> nr = filp->f_pos % <a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>; <a name=L31 href="source/fs/file_dev.c#L31">31</a> chars = <a href="ident?i=MIN">MIN</a>( <a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>-nr , left ); <a name=L32 href="source/fs/file_dev.c#L32">32</a> filp->f_pos += chars; <a name=L33 href="source/fs/file_dev.c#L33">33</a> left -= chars; <a name=L34 href="source/fs/file_dev.c#L34">34</a> if (bh) { <a name=L35 href="source/fs/file_dev.c#L35">35</a> char * p = nr + bh->b_data; <a name=L36 href="source/fs/file_dev.c#L36">36</a> while (chars-->0) <a name=L37 href="source/fs/file_dev.c#L37">37</a> <a href="ident?i=put_fs_byte">put_fs_byte</a>(*(p++),<a href="ident?i=buf">buf</a>++); <a name=L38 href="source/fs/file_dev.c#L38">38</a> <a href="ident?i=brelse">brelse</a>(bh); <a name=L39 href="source/fs/file_dev.c#L39">39</a> } else { <a name=L40 href="source/fs/file_dev.c#L40">40</a> while (chars-->0) <a name=L41 href="source/fs/file_dev.c#L41">41</a> <a href="ident?i=put_fs_byte">put_fs_byte</a>(0,<a href="ident?i=buf">buf</a>++); <a name=L42 href="source/fs/file_dev.c#L42">42</a> } <a name=L43 href="source/fs/file_dev.c#L43">43</a> } <a name=L44 href="source/fs/file_dev.c#L44">44</a> inode->i_atime = <a href="ident?i=CURRENT_TIME">CURRENT_TIME</a>; <a name=L45 href="source/fs/file_dev.c#L45">45</a> return (<a href="ident?i=count">count</a>-left)?(<a href="ident?i=count">count</a>-left):-<a href="ident?i=ERROR">ERROR</a>; <a name=L46 href="source/fs/file_dev.c#L46">46</a> } <a name=L47 href="source/fs/file_dev.c#L47">47</a> <a name=L48 href="source/fs/file_dev.c#L48">48</a> int <a href="ident?i=file_write">file_write</a>(struct <a href="ident?i=m_inode">m_inode</a> * inode, struct <a href="ident?i=file">file</a> * filp, char * <a href="ident?i=buf">buf</a>, int <a href="ident?i=count">count</a>) <a name=L49 href="source/fs/file_dev.c#L49">49</a> { <a name=L50 href="source/fs/file_dev.c#L50">50</a> <a href="ident?i=off_t">off_t</a> <a href="ident?i=pos">pos</a>; <a name=L51 href="source/fs/file_dev.c#L51">51</a> int block,c; <a name=L52 href="source/fs/file_dev.c#L52">52</a> struct <a href="ident?i=buffer_head">buffer_head</a> * bh; <a name=L53 href="source/fs/file_dev.c#L53">53</a> char * p; <a name=L54 href="source/fs/file_dev.c#L54">54</a> int i=0; <a name=L55 href="source/fs/file_dev.c#L55">55</a> <a name=L56 href="source/fs/file_dev.c#L56">56</a> <b><i>/*</i></b> <a name=L57 href="source/fs/file_dev.c#L57">57</a> <b><i> * ok, append may not work when many processes are writing at the same time</i></b> <a name=L58 href="source/fs/file_dev.c#L58">58</a> <b><i> * but so what. That way leads to madness anyway.</i></b> <a name=L59 href="source/fs/file_dev.c#L59">59</a> <b><i> */</i></b> <a name=L60 href="source/fs/file_dev.c#L60">60</a> if (filp->f_flags & <a href="ident?i=O_APPEND">O_APPEND</a>) <a name=L61 href="source/fs/file_dev.c#L61">61</a> <a href="ident?i=pos">pos</a> = inode->i_size; <a name=L62 href="source/fs/file_dev.c#L62">62</a> else <a name=L63 href="source/fs/file_dev.c#L63">63</a> <a href="ident?i=pos">pos</a> = filp->f_pos; <a name=L64 href="source/fs/file_dev.c#L64">64</a> while (i<<a href="ident?i=count">count</a>) { <a name=L65 href="source/fs/file_dev.c#L65">65</a> if (!(block = <a href="ident?i=create_block">create_block</a>(inode,<a href="ident?i=pos">pos</a>/<a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>))) <a name=L66 href="source/fs/file_dev.c#L66">66</a> break; <a name=L67 href="source/fs/file_dev.c#L67">67</a> if (!(bh=<a href="ident?i=bread">bread</a>(inode->i_dev,block))) <a name=L68 href="source/fs/file_dev.c#L68">68</a> break; <a name=L69 href="source/fs/file_dev.c#L69">69</a> c = <a href="ident?i=pos">pos</a> % <a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>; <a name=L70 href="source/fs/file_dev.c#L70">70</a> p = c + bh->b_data; <a name=L71 href="source/fs/file_dev.c#L71">71</a> bh->b_dirt = 1; <a name=L72 href="source/fs/file_dev.c#L72">72</a> c = <a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>-c; <a name=L73 href="source/fs/file_dev.c#L73">73</a> if (c > <a href="ident?i=count">count</a>-i) c = <a href="ident?i=count">count</a>-i; <a name=L74 href="source/fs/file_dev.c#L74">74</a> <a href="ident?i=pos">pos</a> += c; <a name=L75 href="source/fs/file_dev.c#L75">75</a> if (<a href="ident?i=pos">pos</a> > inode->i_size) { <a name=L76 href="source/fs/file_dev.c#L76">76</a> inode->i_size = <a href="ident?i=pos">pos</a>; <a name=L77 href="source/fs/file_dev.c#L77">77</a> inode->i_dirt = 1; <a name=L78 href="source/fs/file_dev.c#L78">78</a> } <a name=L79 href="source/fs/file_dev.c#L79">79</a> i += c; <a name=L80 href="source/fs/file_dev.c#L80">80</a> while (c-->0) <a name=L81 href="source/fs/file_dev.c#L81">81</a> *(p++) = <a href="ident?i=get_fs_byte">get_fs_byte</a>(<a href="ident?i=buf">buf</a>++); <a name=L82 href="source/fs/file_dev.c#L82">82</a> <a href="ident?i=brelse">brelse</a>(bh); <a name=L83 href="source/fs/file_dev.c#L83">83</a> } <a name=L84 href="source/fs/file_dev.c#L84">84</a> inode->i_mtime = <a href="ident?i=CURRENT_TIME">CURRENT_TIME</a>; <a name=L85 href="source/fs/file_dev.c#L85">85</a> if (!(filp->f_flags & <a href="ident?i=O_APPEND">O_APPEND</a>)) { <a name=L86 href="source/fs/file_dev.c#L86">86</a> filp->f_pos = <a href="ident?i=pos">pos</a>; <a name=L87 href="source/fs/file_dev.c#L87">87</a> inode->i_ctime = <a href="ident?i=CURRENT_TIME">CURRENT_TIME</a>; <a name=L88 href="source/fs/file_dev.c#L88">88</a> } <a name=L89 href="source/fs/file_dev.c#L89">89</a> return (i?i:-1); <a name=L90 href="source/fs/file_dev.c#L90">90</a> } <a name=L91 href="source/fs/file_dev.c#L91">91</a> </pre><hr><div align=center> [<b><i>源代码浏览</i></b>] [<a href="diff/fs/file_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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