📄 bitmap.c
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<!doctype html public "-//W3C//DTD HTML 3.2//EN"><html><head><title>Linux/fs/bitmap.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/bitmap.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/bitmap.c">bitmap.c</a></h1><div align=center> <b>版本:</b> [<a href="source/fs/bitmap.c?v=1.0">1.0</a>] [<a href="source/fs/bitmap.c?v=0.99.11">0.99.11</a>] [<a href="source/fs/bitmap.c?v=0.99">0.99</a>] [<a href="source/fs/bitmap.c?v=0.97">0.97</a>] [<a href="source/fs/bitmap.c?v=0.96a">0.96a</a>] [<a href="source/fs/bitmap.c?v=0.95">0.95</a>] [<a href="source/fs/bitmap.c?v=0.12">0.12</a>] [<b><i>0.11</i></b>] [<a href="source/fs/bitmap.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/bitmap.c#L1">1</a> <b><i>/*</i></b> <a name=L2 href="source/fs/bitmap.c#L2">2</a> <b><i> * linux/fs/bitmap.c</i></b> <a name=L3 href="source/fs/bitmap.c#L3">3</a> <b><i> *</i></b> <a name=L4 href="source/fs/bitmap.c#L4">4</a> <b><i> * (C) 1991 Linus Torvalds</i></b> <a name=L5 href="source/fs/bitmap.c#L5">5</a> <b><i> */</i></b> <a name=L6 href="source/fs/bitmap.c#L6">6</a> <a name=L7 href="source/fs/bitmap.c#L7">7</a> <b><i>/* bitmap.c contains the code that handles the inode and block bitmaps */</i></b> <a name=L8 href="source/fs/bitmap.c#L8">8</a> #include <string.h> <a name=L9 href="source/fs/bitmap.c#L9">9</a> <a name=L10 href="source/fs/bitmap.c#L10">10</a> #include <linux/sched.h> <a name=L11 href="source/fs/bitmap.c#L11">11</a> #include <linux/kernel.h> <a name=L12 href="source/fs/bitmap.c#L12">12</a> <a name=L13 href="source/fs/bitmap.c#L13">13</a> #define <a href="ident?i=clear_block">clear_block</a>(addr) \ <a name=L14 href="source/fs/bitmap.c#L14">14</a> __asm__(<i>"cld\n\t"</i> \ <a name=L15 href="source/fs/bitmap.c#L15">15</a> <i>"rep\n\t"</i> \ <a name=L16 href="source/fs/bitmap.c#L16">16</a> <i>"stosl"</i> \ <a name=L17 href="source/fs/bitmap.c#L17">17</a> ::<i>"a"</i> (0),<i>"c"</i> (<a href="ident?i=BLOCK_SIZE">BLOCK_SIZE</a>/4),<i>"D"</i> ((long) (addr)):<i>"cx"</i>,<i>"di"</i>) <a name=L18 href="source/fs/bitmap.c#L18">18</a> <a name=L19 href="source/fs/bitmap.c#L19">19</a> #define <a href="ident?i=set_bit">set_bit</a>(nr,addr) ({\ <a name=L20 href="source/fs/bitmap.c#L20">20</a> register int res __asm__(<i>"ax"</i>); \ <a name=L21 href="source/fs/bitmap.c#L21">21</a> __asm__ __volatile__(<i>"btsl %2,%3\n\tsetb %%al"</i>: \ <a name=L22 href="source/fs/bitmap.c#L22">22</a> <i>"=a"</i> (res):<i>""</i> (0),<i>"r"</i> (nr),<i>"m"</i> (*(addr))); \ <a name=L23 href="source/fs/bitmap.c#L23">23</a> res;}) <a name=L24 href="source/fs/bitmap.c#L24">24</a> <a name=L25 href="source/fs/bitmap.c#L25">25</a> #define <a href="ident?i=clear_bit">clear_bit</a>(nr,addr) ({\ <a name=L26 href="source/fs/bitmap.c#L26">26</a> register int res __asm__(<i>"ax"</i>); \ <a name=L27 href="source/fs/bitmap.c#L27">27</a> __asm__ __volatile__(<i>"btrl %2,%3\n\tsetnb %%al"</i>: \ <a name=L28 href="source/fs/bitmap.c#L28">28</a> <i>"=a"</i> (res):<i>""</i> (0),<i>"r"</i> (nr),<i>"m"</i> (*(addr))); \ <a name=L29 href="source/fs/bitmap.c#L29">29</a> res;}) <a name=L30 href="source/fs/bitmap.c#L30">30</a> <a name=L31 href="source/fs/bitmap.c#L31">31</a> #define <a href="ident?i=find_first_zero">find_first_zero</a>(addr) ({ \ <a name=L32 href="source/fs/bitmap.c#L32">32</a> int __res; \ <a name=L33 href="source/fs/bitmap.c#L33">33</a> __asm__(<i>"cld\n"</i> \ <a name=L34 href="source/fs/bitmap.c#L34">34</a> <i>"1:\tlodsl\n\t"</i> \ <a name=L35 href="source/fs/bitmap.c#L35">35</a> <i>"notl %%eax\n\t"</i> \ <a name=L36 href="source/fs/bitmap.c#L36">36</a> <i>"bsfl %%eax,%%edx\n\t"</i> \ <a name=L37 href="source/fs/bitmap.c#L37">37</a> <i>"je 2f\n\t"</i> \ <a name=L38 href="source/fs/bitmap.c#L38">38</a> <i>"addl %%edx,%%ecx\n\t"</i> \ <a name=L39 href="source/fs/bitmap.c#L39">39</a> <i>"jmp 3f\n"</i> \ <a name=L40 href="source/fs/bitmap.c#L40">40</a> <i>"2:\taddl $32,%%ecx\n\t"</i> \ <a name=L41 href="source/fs/bitmap.c#L41">41</a> <i>"cmpl $8192,%%ecx\n\t"</i> \ <a name=L42 href="source/fs/bitmap.c#L42">42</a> <i>"jl 1b\n"</i> \ <a name=L43 href="source/fs/bitmap.c#L43">43</a> <i>"3:"</i> \ <a name=L44 href="source/fs/bitmap.c#L44">44</a> :<i>"=c"</i> (__res):<i>"c"</i> (0),<i>"S"</i> (addr):<i>"ax"</i>,<i>"dx"</i>,<i>"si"</i>); \ <a name=L45 href="source/fs/bitmap.c#L45">45</a> __res;}) <a name=L46 href="source/fs/bitmap.c#L46">46</a> <a name=L47 href="source/fs/bitmap.c#L47">47</a> void <a href="ident?i=free_block">free_block</a>(int dev, int block) <a name=L48 href="source/fs/bitmap.c#L48">48</a> { <a name=L49 href="source/fs/bitmap.c#L49">49</a> struct <a href="ident?i=super_block">super_block</a> * sb; <a name=L50 href="source/fs/bitmap.c#L50">50</a> struct <a href="ident?i=buffer_head">buffer_head</a> * bh; <a name=L51 href="source/fs/bitmap.c#L51">51</a> <a name=L52 href="source/fs/bitmap.c#L52">52</a> if (!(sb = <a href="ident?i=get_super">get_super</a>(dev))) <a name=L53 href="source/fs/bitmap.c#L53">53</a> <a href="ident?i=panic">panic</a>(<i>"trying to free block on nonexistent device"</i>); <a name=L54 href="source/fs/bitmap.c#L54">54</a> if (block < sb->s_firstdatazone || block >= sb->s_nzones) <a name=L55 href="source/fs/bitmap.c#L55">55</a> <a href="ident?i=panic">panic</a>(<i>"trying to free block not in datazone"</i>); <a name=L56 href="source/fs/bitmap.c#L56">56</a> bh = <a href="ident?i=get_hash_table">get_hash_table</a>(dev,block); <a name=L57 href="source/fs/bitmap.c#L57">57</a> if (bh) { <a name=L58 href="source/fs/bitmap.c#L58">58</a> if (bh->b_count != 1) { <a name=L59 href="source/fs/bitmap.c#L59">59</a> <a href="ident?i=printk">printk</a>(<i>"trying to free block (%04x:%d), count=%d\n"</i>, <a name=L60 href="source/fs/bitmap.c#L60">60</a> dev,block,bh->b_count); <a name=L61 href="source/fs/bitmap.c#L61">61</a> return; <a name=L62 href="source/fs/bitmap.c#L62">62</a> } <a name=L63 href="source/fs/bitmap.c#L63">63</a> bh->b_dirt=0; <a name=L64 href="source/fs/bitmap.c#L64">64</a> bh->b_uptodate=0; <a name=L65 href="source/fs/bitmap.c#L65">65</a> <a href="ident?i=brelse">brelse</a>(bh); <a name=L66 href="source/fs/bitmap.c#L66">66</a> } <a name=L67 href="source/fs/bitmap.c#L67">67</a> block -= sb->s_firstdatazone - 1 ; <a name=L68 href="source/fs/bitmap.c#L68">68</a> if (<a href="ident?i=clear_bit">clear_bit</a>(block&8191,sb->s_zmap[block/8192]->b_data)) { <a name=L69 href="source/fs/bitmap.c#L69">69</a> <a href="ident?i=printk">printk</a>(<i>"block (%04x:%d) "</i>,dev,block+sb->s_firstdatazone-1); <a name=L70 href="source/fs/bitmap.c#L70">70</a> <a href="ident?i=panic">panic</a>(<i>"free_block: bit already cleared"</i>); <a name=L71 href="source/fs/bitmap.c#L71">71</a> } <a name=L72 href="source/fs/bitmap.c#L72">72</a> sb->s_zmap[block/8192]->b_dirt = 1; <a name=L73 href="source/fs/bitmap.c#L73">73</a> } <a name=L74 href="source/fs/bitmap.c#L74">74</a> ⌨️ 快捷键说明
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