[media] v4l2-dev/ioctl.c: add vb2_queue support to video_device

This prepares struct video_device for easier integration with vb2.

It also introduces a new lock that protects the vb2_queue. It is up
to the driver to use it or not. And the driver can associate an owner
filehandle with the queue to check whether queuing requests are
permitted for the calling filehandle.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 5 insertions, 11 deletions

diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index c2122e53f051..b82778174eef 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -348,20 +348,14 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
         int ret = -ENODEV;
 
         if (vdev->fops->unlocked_ioctl) {
-                bool locked = false;
+                struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
 
-                if (vdev->lock) {
-                        /* always lock unless the cmd is marked as "don't use lock" */
-                        locked = !v4l2_is_known_ioctl(cmd) ||
-                                 !test_bit(_IOC_NR(cmd), vdev->disable_locking);
-
-                        if (locked && mutex_lock_interruptible(vdev->lock))
-                                return -ERESTARTSYS;
-                }
+                if (lock && mutex_lock_interruptible(lock))
+                        return -ERESTARTSYS;
                 if (video_is_registered(vdev))
                         ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
-                if (locked)
-                        mutex_unlock(vdev->lock);
+                if (lock)
+                        mutex_unlock(lock);
         } else if (vdev->fops->ioctl) {
                 /* This code path is a replacement for the BKL. It is a major
                  * hack but it will have to do for those drivers that are not