diff options
| -rw-r--r-- | drivers/media/media-device.c | 15 | ||||
| -rw-r--r-- | drivers/media/media-devnode.c | 19 | ||||
| -rw-r--r-- | include/media/media-devnode.h | 14 |
3 files changed, 34 insertions, 14 deletions
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c index c6f9447c4586..2a489e6debc0 100644 --- a/drivers/media/media-device.c +++ b/drivers/media/media-device.c @@ -407,6 +407,7 @@ int __must_check __media_device_register(struct media_device *mdev, if (ret < 0) { /* devnode free is handled in media_devnode_*() */ mdev->devnode = NULL; + media_devnode_unregister_prepare(devnode); media_devnode_unregister(devnode); return ret; } @@ -425,16 +426,16 @@ void media_device_unregister(struct media_device *mdev) struct media_entity *entity; struct media_entity *next; + /* Clear the devnode register bit to avoid races with media dev open */ + media_devnode_unregister_prepare(mdev->devnode); + list_for_each_entry_safe(entity, next, &mdev->entities, list) media_device_unregister_entity(entity); - /* Check if mdev devnode was registered */ - if (media_devnode_is_registered(mdev->devnode)) { - device_remove_file(&mdev->devnode->dev, &dev_attr_model); - media_devnode_unregister(mdev->devnode); - /* devnode free is handled in media_devnode_*() */ - mdev->devnode = NULL; - } + device_remove_file(&mdev->devnode->dev, &dev_attr_model); + media_devnode_unregister(mdev->devnode); + /* devnode free is handled in media_devnode_*() */ + mdev->devnode = NULL; } EXPORT_SYMBOL_GPL(media_device_unregister); diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c index 45bb70d27224..e887120d19aa 100644 --- a/drivers/media/media-devnode.c +++ b/drivers/media/media-devnode.c @@ -302,6 +302,17 @@ cdev_add_error: return ret; } +void media_devnode_unregister_prepare(struct media_devnode *devnode) +{ + /* Check if devnode was ever registered at all */ + if (!media_devnode_is_registered(devnode)) + return; + + mutex_lock(&media_devnode_lock); + clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); + mutex_unlock(&media_devnode_lock); +} + /** * media_devnode_unregister - unregister a media device node * @devnode: the device node to unregister @@ -309,17 +320,11 @@ cdev_add_error: * This unregisters the passed device. Future open calls will be met with * errors. * - * This function can safely be called if the device node has never been - * registered or has already been unregistered. + * Should be called after media_devnode_unregister_prepare() */ void media_devnode_unregister(struct media_devnode *devnode) { - /* Check if devnode was ever registered at all */ - if (!media_devnode_is_registered(devnode)) - return; - mutex_lock(&media_devnode_lock); - clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); /* Delete the cdev on this minor as well */ cdev_del(&devnode->cdev); mutex_unlock(&media_devnode_lock); diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h index 345d00a8f02b..6b370e97efae 100644 --- a/include/media/media-devnode.h +++ b/include/media/media-devnode.h @@ -89,6 +89,20 @@ struct media_devnode { int __must_check media_devnode_register(struct media_device *mdev, struct media_devnode *devnode, struct module *owner); + +/** + * media_devnode_unregister_prepare - clear the media device node register bit + * @devnode: the device node to prepare for unregister + * + * This clears the passed device register bit. Future open calls will be met + * with errors. Should be called before media_devnode_unregister() to avoid + * races with unregister and device file open calls. + * + * This function can safely be called if the device node has never been + * registered or has already been unregistered. + */ +void media_devnode_unregister_prepare(struct media_devnode *devnode); + void media_devnode_unregister(struct media_devnode *devnode); static inline struct media_devnode *media_devnode_data(struct file *filp) |