On Mon, 2018-05-14 at 13:55 +0200, Hans Verkuil wrote:
> From: Hans Verkuil <hansverk@xxxxxxxxx>
>
> The ioctl serialization mutex (vdev->lock or q->lock for vb2 queues)
> was taken at the highest level in v4l2-dev.c. This prevents more
> fine-grained locking since at that level we cannot examine the ioctl
> arguments, we can only do that after video_usercopy is called.
>
> So push the locking down to __video_do_ioctl() and subdev_do_ioctl_lock().
>
> This also allows us to make a few functions in v4l2-ioctl.c static and
> video_usercopy() is no longer exported.
>
> The locking scheme is not changed by this patch, just pushed down.
>
> Signed-off-by: Hans Verkuil <hansverk@xxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-dev.c | 6 ------
> drivers/media/v4l2-core/v4l2-ioctl.c | 17 ++++++++++++++---
> drivers/media/v4l2-core/v4l2-subdev.c | 17 ++++++++++++++++-
> include/media/v4l2-dev.h | 9 ---------
> include/media/v4l2-ioctl.h | 12 ------------
> 5 files changed, 30 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
> index c4f4357e9ca4..4ffd7d60a901 100644
> --- a/drivers/media/v4l2-core/v4l2-dev.c
> +++ b/drivers/media/v4l2-core/v4l2-dev.c
> @@ -360,14 +360,8 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> int ret = -ENODEV;
>
> if (vdev->fops->unlocked_ioctl) {
> - struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
> -
> - if (lock && mutex_lock_interruptible(lock))
> - return -ERESTARTSYS;
> if (video_is_registered(vdev))
This is_registered check looks spurious.
Other than that, it looks good.
