[PATCH v2] nvme-pci: allocate device queues storage space at probe

[Sagi Grimberg]

> Hi Sagi,
> 
> This patch introduces a new kernel oops:

Hi Ming, thanks for testing.

It looks like pci resets are not serialized which is in general not
healthy and forcing the driver to handle tough races. I think that not
serializing it is buggy to begin with.

I think [1] should solve the issue you are seeing (and I think correct
on its own regardless).

Keith, Christoph, any objections?

[1]:
--
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index c7e7b8e22bdb..98e4c28ebaaa 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -112,7 +112,7 @@ int nvme_reset_ctrl(struct nvme_ctrl *ctrl)
  }
  EXPORT_SYMBOL_GPL(nvme_reset_ctrl);

-static int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl)
+int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl)
  {
         int ret;

@@ -121,6 +121,7 @@ static int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl)
                 flush_work(&ctrl->reset_work);
         return ret;
  }
+EXPORT_SYMBOL_GPL(nvme_reset_ctrl_sync);

  static void nvme_delete_ctrl_work(struct work_struct *work)
  {
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 9df2dc063f48..67ab41d71038 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -400,6 +400,7 @@ int nvme_set_queue_count(struct nvme_ctrl *ctrl, int 
*count);
  void nvme_start_keep_alive(struct nvme_ctrl *ctrl);
  void nvme_stop_keep_alive(struct nvme_ctrl *ctrl);
  int nvme_reset_ctrl(struct nvme_ctrl *ctrl);
+int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl);
  int nvme_delete_ctrl(struct nvme_ctrl *ctrl);
  int nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl);

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 77200fb89a64..8b116f1ebe66 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2514,7 +2514,7 @@ static void nvme_reset_prepare(struct pci_dev *pdev)
  static void nvme_reset_done(struct pci_dev *pdev)
  {
         struct nvme_dev *dev = pci_get_drvdata(pdev);
-       nvme_reset_ctrl(&dev->ctrl);
+       nvme_reset_ctrl_sync(&dev->ctrl);
  }

  static void nvme_shutdown(struct pci_dev *pdev)
--