unlocked_ioctl与正常的ioctl [英] unlocked_ioctl vs normal ioctl

问题描述

在我的驾驶file_operations结构，我有：

In my driver's file_operations structure, I have:

struct file_operations Fops = {
  read:    device_read,
  write:   device_write,
  unlocked_ioctl:   device_ioctl,
  ...
};

即。有没有使用的ioctl领域。这是足以避免大内核锁，没有任何同步进入device_ioctl（）？或做我必须要改变的ioctl（）在code的用户空间部分过电话？

I.e. there is no ioctl field used. Is this sufficient to avoid Big Kernel Lock and enter into device_ioctl() without any synchronization? Or do I have to change ioctl() calls in userspace part of the code too?

推荐答案

嗯，我解决了这个。它也需要改变device_ioctl功能的签名。有没有inode的参数，也是函数应返回长。就像在以下修补程序：

Uhm, I solved this. It is also required to change signature of device_ioctl function. There is no inode parameter, and also the function should return long. Just like in following patch:

-static int st_ioctl(struct inode *inode, struct file *file,
- unsigned int cmd_in, unsigned long arg)
+static long st_ioctl(struct file *file, unsigned int cmd_in, unsigned long arg)
{

（来源：<一个href=\"http://linux.derkeiler.com/Mailing-Lists/Kernel/2008-01/msg06799.html\">http://linux.derkeiler.com/Mailing-Lists/Kernel/2008-01/msg06799.html)

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