On Wed, Oct 18, 2017 at 06:52:54PM +0200, Christoph Hellwig wrote:
> +
> +static void nvme_put_subsystem(struct nvme_subsystem *subsys)
> +{
> + put_device(&subsys->dev);
> +}
<snip>
> +static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
> +{
> + struct nvme_subsystem *subsys, *found;
> + int ret;
> +
> + subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
> + if (!subsys)
> + return -ENOMEM;
> + INIT_LIST_HEAD(&subsys->ctrls);
> + nvme_init_subnqn(subsys, ctrl, id);
> + memcpy(subsys->serial, id->sn, sizeof(subsys->serial));
> + memcpy(subsys->model, id->mn, sizeof(subsys->model));
> + memcpy(subsys->firmware_rev, id->fr, sizeof(subsys->firmware_rev));
> + subsys->vendor_id = le16_to_cpu(id->vid);
> + mutex_init(&subsys->lock);
> +
> + subsys->dev.class = nvme_subsys_class;
> + subsys->dev.release = nvme_free_subsystem;
> + dev_set_name(&subsys->dev, subsys->subnqn);
> + device_initialize(&subsys->dev);
> +
> + mutex_lock(&nvme_subsystems_lock);
> + found = __nvme_find_get_subsystem(subsys->subnqn);
> + if (found) {
> + /*
> + * Verify that the subsystem actually supports multiple
> + * controllers, else bail out.
> + */
> + if (!(id->cmic & (1 << 1))) {
> + dev_err(ctrl->device,
> + "ignoring ctrl due to duplicate subnqn (%s).\n",
> + found->subnqn);
> + nvme_put_subsystem(found);
> + ret = -EINVAL;
> + goto out_unlock;
> + }
> +
> + kfree(subsys);
> + subsys = found;
> + } else {
> + ret = device_add(&subsys->dev);
> + if (ret) {
> + dev_err(ctrl->device,
> + "failed to register subsystem device.\n");
> + goto out_unlock;
> + }
> + list_add_tail(&subsys->entry, &nvme_subsystems);
> + }
I'm having some trouble with this one. The device_initialize() initializes
the kobj's reference counter, and then the device_add() takes another
reference on it.
The teardown, though, only calls put_device(). Where's the call to
device_del() supposed to go that ultimately drops the last reference
to call the .release 'nvme_free_subsystem'?
