On Mon, Sep 18, 2017 at 04:14:50PM -0700, Christoph Hellwig wrote:
> +static int nvme_init_subsystem(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
> +{
> + struct nvme_subsystem *subsys, *found;
> +
> + subsys = kzalloc(sizeof(*subsys), GFP_KERNEL);
> + if (!subsys)
> + return -ENOMEM;
> + INIT_LIST_HEAD(&subsys->ctrls);
> + kref_init(&subsys->ref);
> + nvme_init_subnqn(subsys, ctrl, id);
> + mutex_init(&subsys->lock);
> +
> + 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.
> + */
> + kfree(subsys);
> + if (!(id->cmic & (1 << 1))) {
> + dev_err(ctrl->device,
> + "ignoring ctrl due to duplicate subnqn (%s).\n",
> + found->subnqn);
> + mutex_unlock(&nvme_subsystems_lock);
> + return -EINVAL;
> + }
> +
> + subsys = found;
> + } else {
> + list_add_tail(&subsys->entry, &nvme_subsystems);
> + }
> +
> + ctrl->subsys = subsys;
> + mutex_unlock(&nvme_subsystems_lock);
> +
> + mutex_lock(&subsys->lock);
> + list_add_tail(&ctrl->subsys_entry, &subsys->ctrls);
> + mutex_unlock(&subsys->lock);
This function is called every time nvme_init_identify is called, which
happens on every controller reset. The controller reset does not remove
itself from the subsystem list of controllers, so its entry is getting
doubly added after a controller reset.
