staging: vme: use image mutex for ioctl()

This implements more granular locking in vme_user_ioctl() by using separate
locks for each devfs device.

This also provides a synchronization between vme_user_read(), vme_user_write()
and vme_user_ioctl().

Signed-off-by: Dmitry Kalinkin <dmitry.kalinkin@gmail.com>
Cc: Martyn Welch <martyn.welch@ge.com>
Cc: Igor Alekseev <igor.alekseev@itep.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dmitry Kalinkin 2015-02-26 18:53:09 +03:00 committed by Greg Kroah-Hartman
parent ad22d55c4b
commit 0cd189a42d

View file

@ -41,7 +41,6 @@
#include "vme_user.h"
static DEFINE_MUTEX(vme_user_mutex);
static const char driver_name[] = "vme_user";
static int bus[VME_USER_BUS_MAX];
@ -555,10 +554,12 @@ static long
vme_user_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
int ret;
struct inode *inode = file_inode(file);
unsigned int minor = MINOR(inode->i_rdev);
mutex_lock(&vme_user_mutex);
ret = vme_user_ioctl(file_inode(file), file, cmd, arg);
mutex_unlock(&vme_user_mutex);
mutex_lock(&image[minor].mutex);
ret = vme_user_ioctl(inode, file, cmd, arg);
mutex_unlock(&image[minor].mutex);
return ret;
}