diff options
| -rw-r--r-- | drivers/vfio/mdev/mdev_core.c | 72 | ||||
| -rw-r--r-- | drivers/vfio/mdev/mdev_private.h | 2 |
2 files changed, 56 insertions, 18 deletions
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c index 0bef0cae1d4b..ae23151442cb 100644 --- a/drivers/vfio/mdev/mdev_core.c +++ b/drivers/vfio/mdev/mdev_core.c @@ -102,11 +102,35 @@ static void mdev_put_parent(struct mdev_parent *parent) kref_put(&parent->ref, mdev_release_parent); } +/* Caller must hold parent unreg_sem read or write lock */ +static void mdev_device_remove_common(struct mdev_device *mdev) +{ + struct mdev_parent *parent; + struct mdev_type *type; + int ret; + + type = to_mdev_type(mdev->type_kobj); + mdev_remove_sysfs_files(&mdev->dev, type); + device_del(&mdev->dev); + parent = mdev->parent; + lockdep_assert_held(&parent->unreg_sem); + ret = parent->ops->remove(mdev); + if (ret) + dev_err(&mdev->dev, "Remove failed: err=%d\n", ret); + + /* Balances with device_initialize() */ + put_device(&mdev->dev); + mdev_put_parent(parent); +} + static int mdev_device_remove_cb(struct device *dev, void *data) { - if (dev_is_mdev(dev)) - mdev_device_remove(dev); + if (dev_is_mdev(dev)) { + struct mdev_device *mdev; + mdev = to_mdev_device(dev); + mdev_device_remove_common(mdev); + } return 0; } @@ -148,6 +172,7 @@ int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops) } kref_init(&parent->ref); + init_rwsem(&parent->unreg_sem); parent->dev = dev; parent->ops = ops; @@ -206,21 +231,23 @@ void mdev_unregister_device(struct device *dev) dev_info(dev, "MDEV: Unregistering\n"); list_del(&parent->next); + mutex_unlock(&parent_list_lock); + + down_write(&parent->unreg_sem); + class_compat_remove_link(mdev_bus_compat_class, dev, NULL); device_for_each_child(dev, NULL, mdev_device_remove_cb); parent_remove_sysfs_files(parent); + up_write(&parent->unreg_sem); - mutex_unlock(&parent_list_lock); mdev_put_parent(parent); } EXPORT_SYMBOL(mdev_unregister_device); -static void mdev_device_release(struct device *dev) +static void mdev_device_free(struct mdev_device *mdev) { - struct mdev_device *mdev = to_mdev_device(dev); - mutex_lock(&mdev_list_lock); list_del(&mdev->next); mutex_unlock(&mdev_list_lock); @@ -229,6 +256,13 @@ static void mdev_device_release(struct device *dev) kfree(mdev); } +static void mdev_device_release(struct device *dev) +{ + struct mdev_device *mdev = to_mdev_device(dev); + + mdev_device_free(mdev); +} + int mdev_device_create(struct kobject *kobj, struct device *dev, const guid_t *uuid) { @@ -265,6 +299,13 @@ int mdev_device_create(struct kobject *kobj, mdev->parent = parent; + /* Check if parent unregistration has started */ + if (!down_read_trylock(&parent->unreg_sem)) { + mdev_device_free(mdev); + ret = -ENODEV; + goto mdev_fail; + } + device_initialize(&mdev->dev); mdev->dev.parent = dev; mdev->dev.bus = &mdev_bus_type; @@ -287,6 +328,7 @@ int mdev_device_create(struct kobject *kobj, mdev->active = true; dev_dbg(&mdev->dev, "MDEV: created\n"); + up_read(&parent->unreg_sem); return 0; @@ -295,6 +337,7 @@ sysfs_fail: add_fail: parent->ops->remove(mdev); ops_create_fail: + up_read(&parent->unreg_sem); put_device(&mdev->dev); mdev_fail: mdev_put_parent(parent); @@ -305,8 +348,6 @@ int mdev_device_remove(struct device *dev) { struct mdev_device *mdev, *tmp; struct mdev_parent *parent; - struct mdev_type *type; - int ret; mdev = to_mdev_device(dev); @@ -329,18 +370,13 @@ int mdev_device_remove(struct device *dev) mdev->active = false; mutex_unlock(&mdev_list_lock); - type = to_mdev_type(mdev->type_kobj); - mdev_remove_sysfs_files(dev, type); - device_del(&mdev->dev); parent = mdev->parent; - ret = parent->ops->remove(mdev); - if (ret) - dev_err(&mdev->dev, "Remove failed: err=%d\n", ret); - - /* Balances with device_initialize() */ - put_device(&mdev->dev); - mdev_put_parent(parent); + /* Check if parent unregistration has started */ + if (!down_read_trylock(&parent->unreg_sem)) + return -ENODEV; + mdev_device_remove_common(mdev); + up_read(&parent->unreg_sem); return 0; } diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h index 924ed2274941..398767526276 100644 --- a/drivers/vfio/mdev/mdev_private.h +++ b/drivers/vfio/mdev/mdev_private.h @@ -23,6 +23,8 @@ struct mdev_parent { struct list_head next; struct kset *mdev_types_kset; struct list_head type_list; + /* Synchronize device creation/removal with parent unregistration */ + struct rw_semaphore unreg_sem; }; struct mdev_device { |