NVMe: Fix hot cpu notification dead lock

[karo-tx-linux.git] / drivers / block / nvme-core.c

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 2af079e571fc72e8df1d534b6675a2f8ec05f983..e0ac1210fe3111edaf45c0072d0e5f41a84ab3f8 100644 (file)
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -73,6 +73,7 @@ static LIST_HEAD(dev_list);
 static struct task_struct *nvme_thread;
 static struct workqueue_struct *nvme_workq;
 static wait_queue_head_t nvme_kthread_wait;
+static struct notifier_block nvme_nb;
 
 static void nvme_reset_failed_dev(struct work_struct *ws);
 
@@ -2115,14 +2116,25 @@ static size_t db_bar_size(struct nvme_dev *dev, unsigned nr_io_queues)
        return 4096 + ((nr_io_queues + 1) * 8 * dev->db_stride);
 }
 
+static void nvme_cpu_workfn(struct work_struct *work)
+{
+       struct nvme_dev *dev = container_of(work, struct nvme_dev, cpu_work);
+       if (dev->initialized)
+               nvme_assign_io_queues(dev);
+}
+
 static int nvme_cpu_notify(struct notifier_block *self,
                                unsigned long action, void *hcpu)
 {
-       struct nvme_dev *dev = container_of(self, struct nvme_dev, nb);
+       struct nvme_dev *dev;
+
        switch (action) {
        case CPU_ONLINE:
        case CPU_DEAD:
-               nvme_assign_io_queues(dev);
+               spin_lock(&dev_list_lock);
+               list_for_each_entry(dev, &dev_list, node)
+                       schedule_work(&dev->cpu_work);
+               spin_unlock(&dev_list_lock);
                break;
        }
        return NOTIFY_OK;
@@ -2191,11 +2203,6 @@ static int nvme_setup_io_queues(struct nvme_dev *dev)
        nvme_free_queues(dev, nr_io_queues + 1);
        nvme_assign_io_queues(dev);
 
-       dev->nb.notifier_call = &nvme_cpu_notify;
-       result = register_hotcpu_notifier(&dev->nb);
-       if (result)
-               goto free_queues;
-
        return 0;
 
  free_queues:
@@ -2495,8 +2502,6 @@ static void nvme_dev_shutdown(struct nvme_dev *dev)
        int i;
 
        dev->initialized = 0;
-       unregister_hotcpu_notifier(&dev->nb);
-
        nvme_dev_list_remove(dev);
 
        if (!dev->bar || (dev->bar && readl(&dev->bar->csts) == -1)) {
@@ -2767,6 +2772,7 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        INIT_LIST_HEAD(&dev->namespaces);
        dev->reset_workfn = nvme_reset_failed_dev;
        INIT_WORK(&dev->reset_work, nvme_reset_workfn);
+       INIT_WORK(&dev->cpu_work, nvme_cpu_workfn);
        dev->pci_dev = pdev;
        pci_set_drvdata(pdev, dev);
        result = nvme_set_instance(dev);
@@ -2836,6 +2842,7 @@ static void nvme_remove(struct pci_dev *pdev)
 
        pci_set_drvdata(pdev, NULL);
        flush_work(&dev->reset_work);
+       flush_work(&dev->cpu_work);
        misc_deregister(&dev->miscdev);
        nvme_dev_remove(dev);
        nvme_dev_shutdown(dev);
@@ -2923,11 +2930,18 @@ static int __init nvme_init(void)
        else if (result > 0)
                nvme_major = result;
 
-       result = pci_register_driver(&nvme_driver);
+       nvme_nb.notifier_call = &nvme_cpu_notify;
+       result = register_hotcpu_notifier(&nvme_nb);
        if (result)
                goto unregister_blkdev;
+
+       result = pci_register_driver(&nvme_driver);
+       if (result)
+               goto unregister_hotcpu;
        return 0;
 
+ unregister_hotcpu:
+       unregister_hotcpu_notifier(&nvme_nb);
  unregister_blkdev:
        unregister_blkdev(nvme_major, "nvme");
  kill_workq:
@@ -2938,6 +2952,7 @@ static int __init nvme_init(void)
 static void __exit nvme_exit(void)
 {
        pci_unregister_driver(&nvme_driver);
+       unregister_hotcpu_notifier(&nvme_nb);
        unregister_blkdev(nvme_major, "nvme");
        destroy_workqueue(nvme_workq);
        BUG_ON(nvme_thread && !IS_ERR(nvme_thread));