Once the memory for the struct mdev_device is allocated it should
immediately be device_initialize()'d and filled in so that put_device()
can always be used to undo the allocation.
Place the mdev_get/put_parent() so that they are clearly protecting the
mdev->parent pointer. Move the final put to the release function so that
the lifetime rules are trivial to understand. Update the goto labels to
follow the normal convention.
Remove mdev_device_free() as the release function via device_put() is now
usable in all cases.
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/vfio/mdev/mdev_core.c | 60 ++++++++++++++++-------------------
1 file changed, 27 insertions(+), 33 deletions(-)
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index 7ec21c907397a5..f7559835b0610f 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -71,7 +71,6 @@ static void mdev_device_remove_common(struct mdev_device *mdev)
/* Balances with device_initialize() */
put_device(&mdev->dev);
- mdev_put_parent(parent);
}
static int mdev_device_remove_cb(struct device *dev, void *data)
@@ -208,8 +207,13 @@ void mdev_unregister_device(struct device *dev)
}
EXPORT_SYMBOL(mdev_unregister_device);
-static void mdev_device_free(struct mdev_device *mdev)
+static void mdev_device_release(struct device *dev)
{
+ struct mdev_device *mdev = to_mdev_device(dev);
+
+ /* Pairs with the get in mdev_device_create() */
+ mdev_put_parent(mdev->parent);
+
mutex_lock(&mdev_list_lock);
list_del(&mdev->next);
mutex_unlock(&mdev_list_lock);
@@ -218,70 +222,61 @@ static void mdev_device_free(struct mdev_device *mdev)
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 mdev_type *type, const guid_t *uuid)
{
int ret;
struct mdev_device *mdev, *tmp;
struct mdev_parent *parent = type->parent;
- mdev_get_parent(parent);
mutex_lock(&mdev_list_lock);
/* Check for duplicate */
list_for_each_entry(tmp, &mdev_list, next) {
if (guid_equal(&tmp->uuid, uuid)) {
mutex_unlock(&mdev_list_lock);
- ret = -EEXIST;
- goto mdev_fail;
+ return -EEXIST;
}
}
mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
if (!mdev) {
mutex_unlock(&mdev_list_lock);
- ret = -ENOMEM;
- goto mdev_fail;
+ return -ENOMEM;
}
+ device_initialize(&mdev->dev);
+ mdev->dev.parent = parent->dev;
+ mdev->dev.bus = &mdev_bus_type;
+ mdev->dev.release = mdev_device_release;
+ mdev->dev.groups = parent->ops->mdev_attr_groups;
+ mdev->type = type;
+ mdev->parent = parent;
+ /* Pairs with the put in mdev_device_release() */
+ mdev_get_parent(parent);
+
guid_copy(&mdev->uuid, uuid);
list_add(&mdev->next, &mdev_list);
mutex_unlock(&mdev_list_lock);
- mdev->parent = parent;
+ dev_set_name(&mdev->dev, "%pUl", uuid);
/* Check if parent unregistration has started */
if (!down_read_trylock(&parent->unreg_sem)) {
- mdev_device_free(mdev);
ret = -ENODEV;
- goto mdev_fail;
+ goto out_put_device;
}
- device_initialize(&mdev->dev);
- mdev->dev.parent = parent->dev;
- mdev->dev.bus = &mdev_bus_type;
- mdev->dev.release = mdev_device_release;
- dev_set_name(&mdev->dev, "%pUl", uuid);
- mdev->dev.groups = parent->ops->mdev_attr_groups;
- mdev->type = type;
-
ret = parent->ops->create(&type->kobj, mdev);
if (ret)
- goto ops_create_fail;
+ goto out_unlock;
ret = device_add(&mdev->dev);
if (ret)
- goto add_fail;
+ goto out_remove;
ret = mdev_create_sysfs_files(mdev);
if (ret)
- goto sysfs_fail;
+ goto out_del;
mdev->active = true;
dev_dbg(&mdev->dev, "MDEV: created\n");
@@ -289,15 +284,14 @@ int mdev_device_create(struct mdev_type *type, const guid_t *uuid)
return 0;
-sysfs_fail:
+out_del:
device_del(&mdev->dev);
-add_fail:
+out_remove:
parent->ops->remove(mdev);
-ops_create_fail:
+out_unlock:
up_read(&parent->unreg_sem);
+out_put_device:
put_device(&mdev->dev);
-mdev_fail:
- mdev_put_parent(parent);
return ret;
}
--
2.31.1
