From 7385014c073263b077442439299fad013edd4409 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 22 Oct 2015 14:03:33 +0200 Subject: [PATCH] nvme: only add a controller to dev_list after it's been fully initialized Without this we can easily get bad derferences on nvmeq->d_db when the nvme kthread tries to poll the CQs for controllers that are in half initialized state. Signed-off-by: Christoph Hellwig Signed-off-by: Keith Busch Signed-off-by: Jens Axboe --- drivers/nvme/host/pci.c | 51 ++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 21 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 1f92b328522a..d82f08d671e6 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -1994,6 +1994,30 @@ static void nvme_disable_io_queues(struct nvme_dev *dev) kthread_stop(kworker_task); } +static int nvme_dev_list_add(struct nvme_dev *dev) +{ + bool start_thread = false; + + 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_all(&nvme_kthread_wait); + } else + wait_event_killable(nvme_kthread_wait, nvme_thread); + + if (IS_ERR_OR_NULL(nvme_thread)) + return nvme_thread ? PTR_ERR(nvme_thread) : -EINTR; + + return 0; +} + /* * Remove the node from the device list and check * for whether or not we need to stop the nvme_thread. @@ -2109,7 +2133,6 @@ static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl) static void nvme_probe_work(struct work_struct *work) { struct nvme_dev *dev = container_of(work, struct nvme_dev, probe_work); - bool start_thread = false; int result; result = nvme_dev_map(dev); @@ -2120,25 +2143,6 @@ static void nvme_probe_work(struct work_struct *work) if (result) 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_all(&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; - } - nvme_init_queue(dev->queues[0], 0); result = nvme_alloc_admin_tags(dev); if (result) @@ -2154,6 +2158,10 @@ static void nvme_probe_work(struct work_struct *work) dev->ctrl.event_limit = 1; + result = nvme_dev_list_add(dev); + if (result) + goto remove; + /* * Keep the controller around but remove all namespaces if we don't have * any working I/O queue. @@ -2168,6 +2176,8 @@ static void nvme_probe_work(struct work_struct *work) return; + remove: + nvme_dev_list_remove(dev); free_tags: nvme_dev_remove_admin(dev); blk_put_queue(dev->ctrl.admin_q); @@ -2175,7 +2185,6 @@ static void nvme_probe_work(struct work_struct *work) dev->queues[0]->tags = NULL; disable: nvme_disable_queue(dev, 0); - nvme_dev_list_remove(dev); unmap: nvme_dev_unmap(dev); out: -- 2.25.1