Hi Hans,
On Mon, Jun 17, 2024 at 11:57:20AM +0200, Hans Verkuil wrote:
> On 10/06/2024 12:05, Sakari Ailus wrote:
> > The list of file handles is needed to deliver media events as well as for
> > other purposes in the future.
> >
> > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> > ---
> > drivers/media/mc/mc-device.c | 19 ++++++++++++++++++-
> > drivers/media/mc/mc-devnode.c | 2 +-
> > include/media/media-devnode.h | 4 +++-
> > 3 files changed, 22 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/media/mc/mc-device.c b/drivers/media/mc/mc-device.c
> > index a9505ab4412d..46d1b0c9d8be 100644
> > --- a/drivers/media/mc/mc-device.c
> > +++ b/drivers/media/mc/mc-device.c
> > @@ -45,8 +45,9 @@ static inline void __user *media_get_uptr(__u64 arg)
> > return (void __user *)(uintptr_t)arg;
> > }
> >
> > -static int media_device_open(struct file *filp)
> > +static int media_device_open(struct media_devnode *devnode, struct file *filp)
> > {
> > + struct media_device *mdev = to_media_device(devnode);
> > struct media_device_fh *fh;
> >
> > fh = kzalloc(sizeof(*fh), GFP_KERNEL);
> > @@ -55,13 +56,23 @@ static int media_device_open(struct file *filp)
> >
> > filp->private_data = &fh->fh;
> >
> > + spin_lock_irq(&mdev->fh_list_lock);
> > + list_add(&fh->mdev_list, &mdev->fh_list);
> > + spin_unlock_irq(&mdev->fh_list_lock);
> > +
> > return 0;
> > }
> >
> > static int media_device_close(struct file *filp)
> > {
> > + struct media_devnode *devnode = media_devnode_data(filp);
> > + struct media_device *mdev = to_media_device(devnode);
> > struct media_device_fh *fh = media_device_fh(filp);
> >
> > + spin_lock_irq(&mdev->fh_list_lock);
> > + list_del(&fh->mdev_list);
> > + spin_unlock_irq(&mdev->fh_list_lock);
> > +
> > kfree(fh);
> >
> > return 0;
> > @@ -769,11 +780,13 @@ void media_device_init(struct media_device *mdev)
> > INIT_LIST_HEAD(&mdev->pads);
> > INIT_LIST_HEAD(&mdev->links);
> > INIT_LIST_HEAD(&mdev->entity_notify);
> > + INIT_LIST_HEAD(&mdev->fh_list);
> >
> > mutex_init(&mdev->req_queue_mutex);
> > mutex_init(&mdev->graph_mutex);
> > ida_init(&mdev->entity_internal_idx);
> > atomic_set(&mdev->request_id, 0);
> > + spin_lock_init(&mdev->fh_list_lock);
> >
> > mdev->devnode.release = media_device_release;
> > media_devnode_init(&mdev->devnode);
> > @@ -830,6 +843,10 @@ void media_device_unregister(struct media_device *mdev)
> > if (!media_devnode_is_registered(&mdev->devnode))
> > return;
> >
> > + spin_lock_irq(&mdev->fh_list_lock);
> > + list_del_init(&mdev->fh_list);
> > + spin_unlock_irq(&mdev->fh_list_lock);
>
> Huh? This doesn't make sense to me. Unregistering the media device
> makes no difference to the list of open filehandles.
Right, I agree with that.
Presumably the list will be empty at release time. I think I'll drop this
and add a sanity check for the list.
>
> > +
> > device_remove_file(&mdev->devnode.dev, &dev_attr_model);
> > dev_dbg(mdev->dev, "Media device unregistering\n");
> > media_devnode_unregister(&mdev->devnode);
> > diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c
> > index 26491daaba96..617156963911 100644
> > --- a/drivers/media/mc/mc-devnode.c
> > +++ b/drivers/media/mc/mc-devnode.c
> > @@ -154,7 +154,7 @@ static int media_open(struct inode *inode, struct file *filp)
> > get_device(&devnode->dev);
> > mutex_unlock(&media_devnode_lock);
> >
> > - ret = devnode->fops->open(filp);
> > + ret = devnode->fops->open(devnode, filp);
> > if (ret) {
> > put_device(&devnode->dev);
> > return ret;
> > diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h
> > index e4e8552598eb..898fa67ca090 100644
> > --- a/include/media/media-devnode.h
> > +++ b/include/media/media-devnode.h
> > @@ -21,6 +21,8 @@
> > #include <linux/device.h>
> > #include <linux/cdev.h>
> >
> > +struct media_devnode;
> > +
> > /*
> > * Flag to mark the media_devnode struct as registered. Drivers must not touch
> > * this flag directly, it will be set and cleared by media_devnode_register and
> > @@ -49,7 +51,7 @@ struct media_file_operations {
> > __poll_t (*poll) (struct file *, struct poll_table_struct *);
> > long (*ioctl) (struct file *, unsigned int, unsigned long);
> > long (*compat_ioctl) (struct file *, unsigned int, unsigned long);
> > - int (*open) (struct file *);
> > + int (*open) (struct media_devnode *, struct file *);
> > int (*release) (struct file *);
> > };
> >
>
--
Kind regards,
Sakari Ailus
