nvme: switch controller refcounting to use struct device
Instead of allocating a separate struct device for the character device
handle embedd it into struct nvme_ctrl and use it for the main controller
refcounting. This removes double refcounting and gets us an automatic
reference for the character device operations. We keep ctrl->device as a
pointer for now to avoid chaning printks all over, but in the future we
could look into message printing helpers that take a controller structure
similar to what other subsystems do.
Note the delete_ctrl operation always already has a reference (either
through sysfs due this change, or because every open file on the
/dev/nvme-fabrics node has a refernece) when it is entered now, so we
don't need to do the unless_zero variant there.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 9f8ae15..3a97daa 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1915,7 +1915,7 @@
ret = -EWOULDBLOCK;
break;
}
- if (!kref_get_unless_zero(&ctrl->kref))
+ if (!kobject_get_unless_zero(&ctrl->device->kobj))
break;
file->private_data = ctrl;
ret = 0;
@@ -2374,7 +2374,7 @@
list_add_tail(&ns->list, &ctrl->namespaces);
mutex_unlock(&ctrl->namespaces_mutex);
- kref_get(&ctrl->kref);
+ nvme_get_ctrl(ctrl);
kfree(id);
@@ -2703,7 +2703,7 @@
void nvme_uninit_ctrl(struct nvme_ctrl *ctrl)
{
- device_destroy(nvme_class, MKDEV(nvme_char_major, ctrl->instance));
+ device_del(ctrl->device);
spin_lock(&dev_list_lock);
list_del(&ctrl->node);
@@ -2711,23 +2711,17 @@
}
EXPORT_SYMBOL_GPL(nvme_uninit_ctrl);
-static void nvme_free_ctrl(struct kref *kref)
+static void nvme_free_ctrl(struct device *dev)
{
- struct nvme_ctrl *ctrl = container_of(kref, struct nvme_ctrl, kref);
+ struct nvme_ctrl *ctrl =
+ container_of(dev, struct nvme_ctrl, ctrl_device);
- put_device(ctrl->device);
ida_simple_remove(&nvme_instance_ida, ctrl->instance);
ida_destroy(&ctrl->ns_ida);
ctrl->ops->free_ctrl(ctrl);
}
-void nvme_put_ctrl(struct nvme_ctrl *ctrl)
-{
- kref_put(&ctrl->kref, nvme_free_ctrl);
-}
-EXPORT_SYMBOL_GPL(nvme_put_ctrl);
-
/*
* Initialize a NVMe controller structures. This needs to be called during
* earliest initialization so that we have the initialized structured around
@@ -2742,7 +2736,6 @@
spin_lock_init(&ctrl->lock);
INIT_LIST_HEAD(&ctrl->namespaces);
mutex_init(&ctrl->namespaces_mutex);
- kref_init(&ctrl->kref);
ctrl->dev = dev;
ctrl->ops = ops;
ctrl->quirks = quirks;
@@ -2755,15 +2748,21 @@
goto out;
ctrl->instance = ret;
- ctrl->device = device_create_with_groups(nvme_class, ctrl->dev,
- MKDEV(nvme_char_major, ctrl->instance),
- ctrl, nvme_dev_attr_groups,
- "nvme%d", ctrl->instance);
- if (IS_ERR(ctrl->device)) {
- ret = PTR_ERR(ctrl->device);
+ device_initialize(&ctrl->ctrl_device);
+ ctrl->device = &ctrl->ctrl_device;
+ ctrl->device->devt = MKDEV(nvme_char_major, ctrl->instance);
+ ctrl->device->class = nvme_class;
+ ctrl->device->parent = ctrl->dev;
+ ctrl->device->groups = nvme_dev_attr_groups;
+ ctrl->device->release = nvme_free_ctrl;
+ dev_set_drvdata(ctrl->device, ctrl);
+ ret = dev_set_name(ctrl->device, "nvme%d", ctrl->instance);
+ if (ret)
goto out_release_instance;
- }
- get_device(ctrl->device);
+ ret = device_add(ctrl->device);
+ if (ret)
+ goto out_free_name;
+
ida_init(&ctrl->ns_ida);
spin_lock(&dev_list_lock);
@@ -2779,6 +2778,8 @@
min(default_ps_max_latency_us, (unsigned long)S32_MAX));
return 0;
+out_free_name:
+ kfree_const(dev->kobj.name);
out_release_instance:
ida_simple_remove(&nvme_instance_ida, ctrl->instance);
out: