Linux 文件缓存 (二)

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close系统调用
1. 首先来到系统调用入口，主要使用__close_fd进行了具体的处理过程
(current->files表示进程当前打开文件表信息，fd为需要关闭的文件索引)
1048 /*
  * Careful here! We test whether the file pointer is NULL before
  * releasing the fd. This ensures that one clone task can‘t release
  * an fd while another clone is opening it.
  */
 SYSCALL_DEFINE1(close, unsigned int, fd)
 {
         int retval = __close_fd(current->files, fd);
 
         /* can‘t restart close syscall because file table entry was cleared */
         if (unlikely(retval == -ERESTARTSYS ||
                      retval == -ERESTARTNOINTR ||
                      retval == -ERESTARTNOHAND ||
                      retval == -ERESTART_RESTARTBLOCK))
                 retval = -EINTR;
 
         return retval;
 }
 EXPORT_SYMBOL(sys_close);

Linux 文件缓存 (二)

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原文地址：http://www.cnblogs.com/lailailai/p/4509654.html