diff options
| -rw-r--r-- | drivers/block/nvme-core.c | 56 |
1 files changed, 42 insertions, 14 deletions
diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c index 7c57b1d955a1..2d69bfec95a4 100644 --- a/drivers/block/nvme-core.c +++ b/drivers/block/nvme-core.c @@ -64,6 +64,7 @@ static DEFINE_SPINLOCK(dev_list_lock); 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 void nvme_reset_failed_dev(struct work_struct *ws); @@ -2374,6 +2375,26 @@ static void nvme_disable_io_queues(struct nvme_dev *dev) kthread_stop(kworker_task); } +/* +* Remove the node from the device list and check +* for whether or not we need to stop the nvme_thread. +*/ +static void nvme_dev_list_remove(struct nvme_dev *dev) +{ + struct task_struct *tmp = NULL; + + spin_lock(&dev_list_lock); + list_del_init(&dev->node); + if (list_empty(&dev_list) && !IS_ERR_OR_NULL(nvme_thread)) { + tmp = nvme_thread; + nvme_thread = NULL; + } + spin_unlock(&dev_list_lock); + + if (tmp) + kthread_stop(tmp); +} + static void nvme_dev_shutdown(struct nvme_dev *dev) { int i; @@ -2381,9 +2402,7 @@ static void nvme_dev_shutdown(struct nvme_dev *dev) dev->initialized = 0; unregister_hotcpu_notifier(&dev->nb); - spin_lock(&dev_list_lock); - list_del_init(&dev->node); - spin_unlock(&dev_list_lock); + nvme_dev_list_remove(dev); if (!dev->bar || (dev->bar && readl(&dev->bar->csts) == -1)) { for (i = dev->queue_count - 1; i >= 0; i--) { @@ -2524,6 +2543,7 @@ static const struct file_operations nvme_dev_fops = { static int nvme_dev_start(struct nvme_dev *dev) { int result; + bool start_thread = false; result = nvme_dev_map(dev); if (result) @@ -2534,9 +2554,24 @@ static int nvme_dev_start(struct nvme_dev *dev) goto unmap; spin_lock(&dev_list_lock); + if (list_empty(&dev_list) && IS_ERR_OR_NULL(nvme_thread)) { + start_thread = true; + nvme_thread = NULL; + } list_add(&dev->node, &dev_list); spin_unlock(&dev_list_lock); + if (start_thread) { + nvme_thread = kthread_run(nvme_kthread, NULL, "nvme"); + wake_up(&nvme_kthread_wait); + } else + wait_event_killable(nvme_kthread_wait, nvme_thread); + + if (IS_ERR_OR_NULL(nvme_thread)) { + result = nvme_thread ? PTR_ERR(nvme_thread) : -EINTR; + goto disable; + } + result = nvme_setup_io_queues(dev); if (result && result != -EBUSY) goto disable; @@ -2545,9 +2580,7 @@ static int nvme_dev_start(struct nvme_dev *dev) disable: nvme_disable_queue(dev, 0); - spin_lock(&dev_list_lock); - list_del_init(&dev->node); - spin_unlock(&dev_list_lock); + nvme_dev_list_remove(dev); unmap: nvme_dev_unmap(dev); return result; @@ -2776,14 +2809,11 @@ static int __init nvme_init(void) { int result; - nvme_thread = kthread_run(nvme_kthread, NULL, "nvme"); - if (IS_ERR(nvme_thread)) - return PTR_ERR(nvme_thread); + init_waitqueue_head(&nvme_kthread_wait); - result = -ENOMEM; nvme_workq = create_singlethread_workqueue("nvme"); if (!nvme_workq) - goto kill_kthread; + return -ENOMEM; result = register_blkdev(nvme_major, "nvme"); if (result < 0) @@ -2800,8 +2830,6 @@ static int __init nvme_init(void) unregister_blkdev(nvme_major, "nvme"); kill_workq: destroy_workqueue(nvme_workq); - kill_kthread: - kthread_stop(nvme_thread); return result; } @@ -2810,7 +2838,7 @@ static void __exit nvme_exit(void) pci_unregister_driver(&nvme_driver); unregister_blkdev(nvme_major, "nvme"); destroy_workqueue(nvme_workq); - kthread_stop(nvme_thread); + BUG_ON(nvme_thread && !IS_ERR(nvme_thread)); } MODULE_AUTHOR("Matthew Wilcox <willy@linux.intel.com>"); |