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📁 一份很好的linux入门资料
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<HTML><HEAD>  <TITLE>BBS水木清华站∶精华区</TITLE></HEAD><BODY><CENTER><H1>BBS水木清华站∶精华区</H1></CENTER>发信人:&nbsp;yuhj&nbsp;(勇&nbsp;&nbsp;梦回唐朝),&nbsp;信区:&nbsp;Linux&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<BR>标&nbsp;&nbsp;题:&nbsp;Re:&nbsp;急问,怎么支持large-file(&gt;2G)&nbsp;<BR>发信站:&nbsp;BBS&nbsp;水木清华站&nbsp;(Wed&nbsp;Jan&nbsp;26&nbsp;18:09:51&nbsp;2000)&nbsp;<BR>&nbsp;<BR>最近在kerneltraffic上看到的讨论，我的印象是ext2fs修改为64bit&nbsp;<BR>指针困难不大，但是off_t修改为64bit有很大困难，好像还根POSIX&nbsp;<BR>的定义不严谨有关。具体的细节没有留心，只是个印象，&nbsp;I&nbsp;could&nbsp;&nbsp;<BR>be&nbsp;wrong.&nbsp;<BR>&nbsp;<BR>嗯，下面是原文的讨论：&nbsp;<BR>＞<I>&nbsp;-&nbsp;why&nbsp;is&nbsp;there&nbsp;a&nbsp;2G&nbsp;limit?&nbsp;</I><BR>&nbsp;<BR>This&nbsp;should&nbsp;go&nbsp;into&nbsp;some&nbsp;FAQ/HOWTO&nbsp;...&nbsp;<BR>The&nbsp;limit&nbsp;comes&nbsp;from&nbsp;this&nbsp;line&nbsp;in&nbsp;&lt;linux/ext2_fs.h&gt;&nbsp;<BR>__u32&nbsp;i_size;&nbsp;/*&nbsp;Size&nbsp;in&nbsp;bytes&nbsp;*/&nbsp;<BR>&nbsp;<BR>&nbsp;<BR>＞<I>&nbsp;-&nbsp;can&nbsp;the&nbsp;2G&nbsp;limit&nbsp;be&nbsp;_safely_&nbsp;increased&nbsp;(to,&nbsp;say,&nbsp;about&nbsp;5G)?&nbsp;</I><BR>＞<I>&nbsp;-&nbsp;if&nbsp;so,&nbsp;what&nbsp;changes&nbsp;are&nbsp;needed&nbsp;in&nbsp;the&nbsp;ext2&nbsp;code&nbsp;to&nbsp;do&nbsp;it?&nbsp;</I><BR>&nbsp;<BR>&nbsp;<BR>You&nbsp;cannot&nbsp;safely&nbsp;change&nbsp;this&nbsp;to&nbsp;__u64,&nbsp;as&nbsp;you'll&nbsp;break&nbsp;the&nbsp;lay-out&nbsp;of&nbsp;<BR>struct&nbsp;ext2_inode,&nbsp;then.&nbsp;About&nbsp;the&nbsp;best&nbsp;proposal&nbsp;I've&nbsp;seen&nbsp;is&nbsp;the&nbsp;one&nbsp;<BR>of&nbsp;Albert&nbsp;Cahalan.&nbsp;You&nbsp;can&nbsp;use&nbsp;another&nbsp;16&nbsp;of&nbsp;the&nbsp;reserved&nbsp;bits&nbsp;to&nbsp;go&nbsp;<BR>to&nbsp;an&nbsp;48&nbsp;bit&nbsp;inode&nbsp;size.&nbsp;You'd&nbsp;have&nbsp;to&nbsp;make&nbsp;sure&nbsp;you&nbsp;don't&nbsp;use&nbsp;<BR>anything&nbsp;that's&nbsp;used&nbsp;by&nbsp;another&nbsp;system&nbsp;already.&nbsp;<BR>&nbsp;<BR>&nbsp;<BR>I&nbsp;don't&nbsp;recall&nbsp;the&nbsp;details.&nbsp;One&nbsp;possibility&nbsp;is&nbsp;to&nbsp;recycle&nbsp;the&nbsp;fields&nbsp;<BR>for&nbsp;the&nbsp;currently&nbsp;unimplemented&nbsp;fragmentation&nbsp;support,&nbsp;which&nbsp;would&nbsp;<BR>give&nbsp;you&nbsp;enough&nbsp;free&nbsp;bits.&nbsp;Apart&nbsp;from&nbsp;this,&nbsp;it&nbsp;seems&nbsp;the&nbsp;Hurd&nbsp;already&nbsp;<BR>occupies&nbsp;everything&nbsp;else.&nbsp;<BR>&nbsp;<BR>&nbsp;<BR>In&nbsp;order&nbsp;to&nbsp;do&nbsp;this&nbsp;safely,&nbsp;you&nbsp;would&nbsp;have&nbsp;to&nbsp;mark&nbsp;the&nbsp;filesystem&nbsp;<BR>with&nbsp;one&nbsp;of&nbsp;the&nbsp;incompatible&nbsp;flags&nbsp;(s_feature_incompat),&nbsp;and&nbsp;then&nbsp;<BR>support&nbsp;the&nbsp;other&nbsp;size&nbsp;bits&nbsp;all&nbsp;over&nbsp;the&nbsp;place.&nbsp;<BR>&nbsp;<BR>&nbsp;<BR>Good&nbsp;luck,&nbsp;<BR>Martin&nbsp;<BR>&nbsp;<BR>&nbsp;<BR>&nbsp;<BR>&nbsp;&nbsp;<BR>【&nbsp;在&nbsp;kxn&nbsp;(烤小牛~信号没糊系统糊了!)&nbsp;的大作中提到:&nbsp;】&nbsp;<BR>∶<I>&nbsp;linux&nbsp;好像是&nbsp;ext2fs&nbsp;的限制吧,&nbsp;如果&nbsp;&gt;&nbsp;2G&nbsp;有人说会&nbsp;crash&nbsp;掉&nbsp;</I><BR>∶<I>&nbsp;lseek&nbsp;用的是&nbsp;off_t&nbsp;,&nbsp;还是留了一手的，&nbsp;&nbsp;</I><BR>&nbsp;<BR>&nbsp;<BR>--&nbsp;<BR>&nbsp;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;聚散无常，&nbsp;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;得失随缘。&nbsp;<BR>&nbsp;<BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<BR>&nbsp;<BR>※&nbsp;修改:·yuhj&nbsp;於&nbsp;Jan&nbsp;26&nbsp;18:18:00&nbsp;修改本文·[FROM:&nbsp;&nbsp;&nbsp;202.204.7.235]&nbsp;<BR>※&nbsp;来源:·BBS&nbsp;水木清华站&nbsp;smth.org·[FROM:&nbsp;202.204.7.235]&nbsp;<BR><CENTER><H1>BBS水木清华站∶精华区</H1></CENTER></BODY></HTML>
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