| Message ID | 20220318211446.11543-2-laurent.pinchart+renesas@ideasonboard.com (mailing list archive) |
|---|---|
| State | New |
| Delegated to: | Kieran Bingham |
| Headers | show |
| Series | media: videobuf2: Expose vb2_queue_is_busy() to drivers | expand |
Hi Laurent, Quoting Laurent Pinchart (2022-03-18 21:14:44) > 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 <laurent.pinchart+renesas@ideasonboard.com> > --- > .../media/common/videobuf2/videobuf2-v4l2.c | 26 +++++++------------ > include/media/videobuf2-v4l2.h | 23 ++++++++++++++-- > 2 files changed, 31 insertions(+), 18 deletions(-) > > diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c > index 6edf4508c636..075d24ebf44c 100644 > --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c > +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c > @@ -977,12 +977,6 @@ EXPORT_SYMBOL_GPL(vb2_poll); > * and so they simplify the driver code. > */ > > -/* The queue is busy if there is a owner and you are not that owner. */ > -static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file) > -{ > - return vdev->queue->owner && vdev->queue->owner != file->private_data; > -} > - > /* vb2 ioctl helpers */ > > int vb2_ioctl_reqbufs(struct file *file, void *priv, > @@ -997,7 +991,7 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv, > p->flags = flags; > if (res) > return res; > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > return -EBUSY; > res = vb2_core_reqbufs(vdev->queue, p->memory, p->flags, &p->count); > /* If count == 0, then the owner has released all buffers and he > @@ -1026,7 +1020,7 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv, > return res != -EBUSY ? res : 0; > if (res) > return res; > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > return -EBUSY; > > res = vb2_create_bufs(vdev->queue, p); > @@ -1041,7 +1035,7 @@ int vb2_ioctl_prepare_buf(struct file *file, void *priv, > { > struct video_device *vdev = video_devdata(file); > > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > return -EBUSY; > return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p); > } > @@ -1060,7 +1054,7 @@ int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p) > { > struct video_device *vdev = video_devdata(file); > > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > return -EBUSY; > return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p); > } > @@ -1070,7 +1064,7 @@ int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p) > { > struct video_device *vdev = video_devdata(file); > > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > return -EBUSY; > return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK); > } > @@ -1080,7 +1074,7 @@ int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i) > { > struct video_device *vdev = video_devdata(file); > > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > return -EBUSY; > return vb2_streamon(vdev->queue, i); > } > @@ -1090,7 +1084,7 @@ int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) > { > struct video_device *vdev = video_devdata(file); > > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > return -EBUSY; > return vb2_streamoff(vdev->queue, i); > } > @@ -1100,7 +1094,7 @@ int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p) > { > struct video_device *vdev = video_devdata(file); > > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > return -EBUSY; > return vb2_expbuf(vdev->queue, p); > } > @@ -1152,7 +1146,7 @@ ssize_t vb2_fop_write(struct file *file, const char __user *buf, > return -EINVAL; > if (lock && mutex_lock_interruptible(lock)) > return -ERESTARTSYS; > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > goto exit; > err = vb2_write(vdev->queue, buf, count, ppos, > file->f_flags & O_NONBLOCK); > @@ -1176,7 +1170,7 @@ ssize_t vb2_fop_read(struct file *file, char __user *buf, > return -EINVAL; > if (lock && mutex_lock_interruptible(lock)) > return -ERESTARTSYS; > - if (vb2_queue_is_busy(vdev, file)) > + if (vb2_queue_is_busy(vdev->queue, file)) > goto exit; > err = vb2_read(vdev->queue, buf, count, ppos, > file->f_flags & O_NONBLOCK); > diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h > index b66585e304e2..1fb99583cd45 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 is has an owner and the owner is not the if it has Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com> > + * @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, > -- > Regards, > > Laurent Pinchart >
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index 6edf4508c636..075d24ebf44c 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -977,12 +977,6 @@ EXPORT_SYMBOL_GPL(vb2_poll); * and so they simplify the driver code. */ -/* The queue is busy if there is a owner and you are not that owner. */ -static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file) -{ - return vdev->queue->owner && vdev->queue->owner != file->private_data; -} - /* vb2 ioctl helpers */ int vb2_ioctl_reqbufs(struct file *file, void *priv, @@ -997,7 +991,7 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv, p->flags = flags; if (res) return res; - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) return -EBUSY; res = vb2_core_reqbufs(vdev->queue, p->memory, p->flags, &p->count); /* If count == 0, then the owner has released all buffers and he @@ -1026,7 +1020,7 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv, return res != -EBUSY ? res : 0; if (res) return res; - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) return -EBUSY; res = vb2_create_bufs(vdev->queue, p); @@ -1041,7 +1035,7 @@ int vb2_ioctl_prepare_buf(struct file *file, void *priv, { struct video_device *vdev = video_devdata(file); - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) return -EBUSY; return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p); } @@ -1060,7 +1054,7 @@ int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p) { struct video_device *vdev = video_devdata(file); - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) return -EBUSY; return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p); } @@ -1070,7 +1064,7 @@ int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p) { struct video_device *vdev = video_devdata(file); - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) return -EBUSY; return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK); } @@ -1080,7 +1074,7 @@ int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i) { struct video_device *vdev = video_devdata(file); - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) return -EBUSY; return vb2_streamon(vdev->queue, i); } @@ -1090,7 +1084,7 @@ int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) { struct video_device *vdev = video_devdata(file); - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) return -EBUSY; return vb2_streamoff(vdev->queue, i); } @@ -1100,7 +1094,7 @@ int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p) { struct video_device *vdev = video_devdata(file); - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) return -EBUSY; return vb2_expbuf(vdev->queue, p); } @@ -1152,7 +1146,7 @@ ssize_t vb2_fop_write(struct file *file, const char __user *buf, return -EINVAL; if (lock && mutex_lock_interruptible(lock)) return -ERESTARTSYS; - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) goto exit; err = vb2_write(vdev->queue, buf, count, ppos, file->f_flags & O_NONBLOCK); @@ -1176,7 +1170,7 @@ ssize_t vb2_fop_read(struct file *file, char __user *buf, return -EINVAL; if (lock && mutex_lock_interruptible(lock)) return -ERESTARTSYS; - if (vb2_queue_is_busy(vdev, file)) + if (vb2_queue_is_busy(vdev->queue, file)) goto exit; err = vb2_read(vdev->queue, buf, count, ppos, file->f_flags & O_NONBLOCK); diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h index b66585e304e2..1fb99583cd45 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 is 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,
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 <laurent.pinchart+renesas@ideasonboard.com> --- .../media/common/videobuf2/videobuf2-v4l2.c | 26 +++++++------------ include/media/videobuf2-v4l2.h | 23 ++++++++++++++-- 2 files changed, 31 insertions(+), 18 deletions(-)