nvme: simplify nvme_open

Now that we are protected against lookup vs free races for the namespace
by using kref_get_unless_zero we don't need the hack of NULLing out the
disk private data during removal.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
This commit is contained in:
Christoph Hellwig 2017-10-18 13:22:00 +02:00
parent 2dd4122854
commit c6424a90da

View file

@ -253,12 +253,6 @@ static void nvme_free_ns(struct kref *kref)
if (ns->ndev)
nvme_nvm_unregister(ns);
if (ns->disk) {
spin_lock(&dev_list_lock);
ns->disk->private_data = NULL;
spin_unlock(&dev_list_lock);
}
put_disk(ns->disk);
ida_simple_remove(&ns->ctrl->ns_ida, ns->instance);
nvme_put_ctrl(ns->ctrl);
@ -270,29 +264,6 @@ static void nvme_put_ns(struct nvme_ns *ns)
kref_put(&ns->kref, nvme_free_ns);
}
static struct nvme_ns *nvme_get_ns_from_disk(struct gendisk *disk)
{
struct nvme_ns *ns;
spin_lock(&dev_list_lock);
ns = disk->private_data;
if (ns) {
if (!kref_get_unless_zero(&ns->kref))
goto fail;
if (!try_module_get(ns->ctrl->ops->module))
goto fail_put_ns;
}
spin_unlock(&dev_list_lock);
return ns;
fail_put_ns:
kref_put(&ns->kref, nvme_free_ns);
fail:
spin_unlock(&dev_list_lock);
return NULL;
}
struct request *nvme_alloc_request(struct request_queue *q,
struct nvme_command *cmd, unsigned int flags, int qid)
{
@ -1056,7 +1027,16 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode,
static int nvme_open(struct block_device *bdev, fmode_t mode)
{
return nvme_get_ns_from_disk(bdev->bd_disk) ? 0 : -ENXIO;
struct nvme_ns *ns = bdev->bd_disk->private_data;
if (!kref_get_unless_zero(&ns->kref))
return -ENXIO;
if (!try_module_get(ns->ctrl->ops->module)) {
kref_put(&ns->kref, nvme_free_ns);
return -ENXIO;
}
return 0;
}
static void nvme_release(struct gendisk *disk, fmode_t mode)