From 7101d1279917e5c7fe897c275c5a0727fe90f3e3 Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Fri, 18 Mar 2022 18:44:35 +0100 Subject: media: videobuf2-v4l2: Expose vb2_queue_is_busy() to drivers vb2 queue ownership is managed by the ioctl handler helpers (vb2_ioctl_*). There are however use cases where drivers can benefit from checking queue ownership, for instance when open-coding an ioctl handler that needs to perform additional checks before calling the corresponding vb2 operation. Expose the vb2_queue_is_busy() function in the videobuf2-v4l2.h header, and change its first argument to a struct vb2_queue pointer as the function name implies it operates on a queue, not a video_device. Signed-off-by: Laurent Pinchart Reviewed-by: Kieran Bingham Signed-off-by: Mauro Carvalho Chehab --- include/media/videobuf2-v4l2.h | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) (limited to 'include/media/videobuf2-v4l2.h') diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h index b66585e304e2..d818d9707695 100644 --- a/include/media/videobuf2-v4l2.h +++ b/include/media/videobuf2-v4l2.h @@ -302,10 +302,29 @@ __poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait); * The following functions are not part of the vb2 core API, but are simple * helper functions that you can use in your struct v4l2_file_operations, * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock - * or video_device->lock is set, and they will set and test vb2_queue->owner - * to check if the calling filehandle is permitted to do the queuing operation. + * or video_device->lock is set, and they will set and test the queue owner + * (vb2_queue->owner) to check if the calling filehandle is permitted to do the + * queuing operation. */ +/** + * vb2_queue_is_busy() - check if the queue is busy + * @q: pointer to &struct vb2_queue with videobuf2 queue. + * @file: file through which the vb2 queue access is performed + * + * The queue is considered busy if it has an owner and the owner is not the + * @file. + * + * Queue ownership is acquired and checked by some of the v4l2_ioctl_ops helpers + * below. Drivers can also use this function directly when they need to + * open-code ioctl handlers, for instance to add additional checks between the + * queue ownership test and the call to the corresponding vb2 operation. + */ +static inline bool vb2_queue_is_busy(struct vb2_queue *q, struct file *file) +{ + return q->owner && q->owner != file->private_data; +} + /* struct v4l2_ioctl_ops helpers */ int vb2_ioctl_reqbufs(struct file *file, void *priv, -- cgit v1.2.3