nvme: Wait for reset state when required
Prevent simultaneous controller disabling/enabling tasks from interfering
with each other through a function to wait until the task successfully
transitioned the controller to the RESETTING state. This ensures disabling
the controller will not be interrupted by another reset path, otherwise
a concurrent reset may leave the controller in the wrong state.
Tested-by: Edmund Nadolski <edmund.nadolski@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index e7e79d6..4b18196 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2463,6 +2463,14 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
mutex_unlock(&dev->shutdown_lock);
}
+static int nvme_disable_prepare_reset(struct nvme_dev *dev, bool shutdown)
+{
+ if (!nvme_wait_reset(&dev->ctrl))
+ return -EBUSY;
+ nvme_dev_disable(dev, shutdown);
+ return 0;
+}
+
static int nvme_setup_prp_pools(struct nvme_dev *dev)
{
dev->prp_page_pool = dma_pool_create("prp list page", dev->dev,
@@ -2510,6 +2518,11 @@ static void nvme_pci_free_ctrl(struct nvme_ctrl *ctrl)
static void nvme_remove_dead_ctrl(struct nvme_dev *dev)
{
+ /*
+ * Set state to deleting now to avoid blocking nvme_wait_reset(), which
+ * may be holding this pci_dev's device lock.
+ */
+ nvme_change_ctrl_state(&dev->ctrl, NVME_CTRL_DELETING);
nvme_get_ctrl(&dev->ctrl);
nvme_dev_disable(dev, false);
nvme_kill_queues(&dev->ctrl);
@@ -2835,19 +2848,28 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
static void nvme_reset_prepare(struct pci_dev *pdev)
{
struct nvme_dev *dev = pci_get_drvdata(pdev);
- nvme_dev_disable(dev, false);
+
+ /*
+ * We don't need to check the return value from waiting for the reset
+ * state as pci_dev device lock is held, making it impossible to race
+ * with ->remove().
+ */
+ nvme_disable_prepare_reset(dev, false);
+ nvme_sync_queues(&dev->ctrl);
}
static void nvme_reset_done(struct pci_dev *pdev)
{
struct nvme_dev *dev = pci_get_drvdata(pdev);
- nvme_reset_ctrl_sync(&dev->ctrl);
+
+ if (!nvme_try_sched_reset(&dev->ctrl))
+ flush_work(&dev->ctrl.reset_work);
}
static void nvme_shutdown(struct pci_dev *pdev)
{
struct nvme_dev *dev = pci_get_drvdata(pdev);
- nvme_dev_disable(dev, true);
+ nvme_disable_prepare_reset(dev, true);
}
/*
@@ -2900,7 +2922,7 @@ static int nvme_resume(struct device *dev)
if (ndev->last_ps == U32_MAX ||
nvme_set_power_state(ctrl, ndev->last_ps) != 0)
- nvme_reset_ctrl(ctrl);
+ return nvme_try_sched_reset(&ndev->ctrl);
return 0;
}
@@ -2928,10 +2950,8 @@ static int nvme_suspend(struct device *dev)
*/
if (pm_suspend_via_firmware() || !ctrl->npss ||
!pcie_aspm_enabled(pdev) ||
- (ndev->ctrl.quirks & NVME_QUIRK_SIMPLE_SUSPEND)) {
- nvme_dev_disable(ndev, true);
- return 0;
- }
+ (ndev->ctrl.quirks & NVME_QUIRK_SIMPLE_SUSPEND))
+ return nvme_disable_prepare_reset(ndev, true);
nvme_start_freeze(ctrl);
nvme_wait_freeze(ctrl);
@@ -2963,9 +2983,8 @@ static int nvme_suspend(struct device *dev)
* Clearing npss forces a controller reset on resume. The
* correct value will be resdicovered then.
*/
- nvme_dev_disable(ndev, true);
+ ret = nvme_disable_prepare_reset(ndev, true);
ctrl->npss = 0;
- ret = 0;
}
unfreeze:
nvme_unfreeze(ctrl);
@@ -2975,9 +2994,7 @@ static int nvme_suspend(struct device *dev)
static int nvme_simple_suspend(struct device *dev)
{
struct nvme_dev *ndev = pci_get_drvdata(to_pci_dev(dev));
-
- nvme_dev_disable(ndev, true);
- return 0;
+ return nvme_disable_prepare_reset(ndev, true);
}
static int nvme_simple_resume(struct device *dev)
@@ -2985,8 +3002,7 @@ static int nvme_simple_resume(struct device *dev)
struct pci_dev *pdev = to_pci_dev(dev);
struct nvme_dev *ndev = pci_get_drvdata(pdev);
- nvme_reset_ctrl(&ndev->ctrl);
- return 0;
+ return nvme_try_sched_reset(&ndev->ctrl);
}
static const struct dev_pm_ops nvme_dev_pm_ops = {