From d22524a4782a943bb02a9cf6885ac470210aabfc Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 18 Oct 2017 13:25:42 +0200 Subject: [PATCH] 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 Reviewed-by: Hannes Reinecke --- drivers/nvme/host/core.c | 43 +++++++++++++++++++------------------- drivers/nvme/host/fc.c | 8 ++----- drivers/nvme/host/nvme.h | 12 ++++++++++- drivers/nvme/host/pci.c | 2 +- drivers/nvme/host/rdma.c | 5 ++--- drivers/nvme/target/loop.c | 2 +- 6 files changed, 39 insertions(+), 33 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 9f8ae15c9fe8..3a97daa163f6 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -1915,7 +1915,7 @@ static int nvme_dev_open(struct inode *inode, struct file *file) 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 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) 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 @@ EXPORT_SYMBOL_GPL(nvme_start_ctrl); 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 @@ void nvme_uninit_ctrl(struct nvme_ctrl *ctrl) } 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 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, 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 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, 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 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, 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: diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index c6c903f1b172..aa9aec6923bb 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -2692,14 +2692,10 @@ nvme_fc_del_nvme_ctrl(struct nvme_ctrl *nctrl) struct nvme_fc_ctrl *ctrl = to_fc_ctrl(nctrl); int ret; - if (!kref_get_unless_zero(&ctrl->ctrl.kref)) - return -EBUSY; - + nvme_get_ctrl(&ctrl->ctrl); ret = __nvme_fc_del_ctrl(ctrl); - if (!ret) flush_workqueue(nvme_wq); - nvme_put_ctrl(&ctrl->ctrl); return ret; @@ -2918,7 +2914,7 @@ nvme_fc_init_ctrl(struct device *dev, struct nvmf_ctrl_options *opts, return ERR_PTR(ret); } - kref_get(&ctrl->ctrl.kref); + nvme_get_ctrl(&ctrl->ctrl); dev_info(ctrl->ctrl.device, "NVME-FC{%d}: new ctrl: NQN \"%s\"\n", diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index cb9d93048f3d..ae60d8342e60 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -127,12 +127,12 @@ struct nvme_ctrl { struct request_queue *admin_q; struct request_queue *connect_q; struct device *dev; - struct kref kref; int instance; struct blk_mq_tag_set *tagset; struct blk_mq_tag_set *admin_tagset; struct list_head namespaces; struct mutex namespaces_mutex; + struct device ctrl_device; struct device *device; /* char device */ struct list_head node; struct ida ns_ida; @@ -279,6 +279,16 @@ static inline void nvme_end_request(struct request *req, __le16 status, blk_mq_complete_request(req); } +static inline void nvme_get_ctrl(struct nvme_ctrl *ctrl) +{ + get_device(ctrl->device); +} + +static inline void nvme_put_ctrl(struct nvme_ctrl *ctrl) +{ + put_device(ctrl->device); +} + void nvme_complete_rq(struct request *req); void nvme_cancel_request(struct request *req, void *data, bool reserved); bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl, diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 11e6fd9d0ba4..7735571ffc9a 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -2292,7 +2292,7 @@ static void nvme_remove_dead_ctrl(struct nvme_dev *dev, int status) { dev_warn(dev->ctrl.device, "Removing after probe failure status: %d\n", status); - kref_get(&dev->ctrl.kref); + nvme_get_ctrl(&dev->ctrl); nvme_dev_disable(dev, false); if (!schedule_work(&dev->remove_work)) nvme_put_ctrl(&dev->ctrl); diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c index 4552744eff45..62b58f9b7d00 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -1793,8 +1793,7 @@ static int nvme_rdma_del_ctrl(struct nvme_ctrl *nctrl) * Keep a reference until all work is flushed since * __nvme_rdma_del_ctrl can free the ctrl mem */ - if (!kref_get_unless_zero(&ctrl->ctrl.kref)) - return -EBUSY; + nvme_get_ctrl(&ctrl->ctrl); ret = __nvme_rdma_del_ctrl(ctrl); if (!ret) flush_work(&ctrl->delete_work); @@ -1955,7 +1954,7 @@ static struct nvme_ctrl *nvme_rdma_create_ctrl(struct device *dev, dev_info(ctrl->ctrl.device, "new ctrl: NQN \"%s\", addr %pISpcs\n", ctrl->ctrl.opts->subsysnqn, &ctrl->addr); - kref_get(&ctrl->ctrl.kref); + nvme_get_ctrl(&ctrl->ctrl); mutex_lock(&nvme_rdma_ctrl_mutex); list_add_tail(&ctrl->list, &nvme_rdma_ctrl_list); diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c index c56354e1e4c6..f83e925fe64a 100644 --- a/drivers/nvme/target/loop.c +++ b/drivers/nvme/target/loop.c @@ -642,7 +642,7 @@ static struct nvme_ctrl *nvme_loop_create_ctrl(struct device *dev, dev_info(ctrl->ctrl.device, "new ctrl: \"%s\"\n", ctrl->ctrl.opts->subsysnqn); - kref_get(&ctrl->ctrl.kref); + nvme_get_ctrl(&ctrl->ctrl); changed = nvme_change_ctrl_state(&ctrl->ctrl, NVME_CTRL_LIVE); WARN_ON_ONCE(!changed);