[PATCH] nvme-pci: fix race between pci reset and nvme probe

[Ming Lei]

After nvme_probe() returns, device lock is released, and PCI reset
handler may come, meantime reset work is just scheduled and should
be in-progress.

When nvme_reset_prepare() is run, all NSs may not be allocated yet
and each NS's request queue won't be frozen by nvme_dev_disable().

But when nvme_reset_done() is called for resetting controller, all
NSs may have been scanned successfully, and nvme_wait_freeze() is
called on un-frozen request queues, then wait forever.

Fix the issue by holding device lock for resetting from nvme probe.

Reported-by: Yi Zhang <yi.zhang at redhat.com>
Link: https://lore.kernel.org/linux-block/CAHj4cs--KPTAGP=jj+7KMe=arDv=HeGeOgs1T8vbusyk=EjXow@mail.gmail.com/#r
Signed-off-by: Ming Lei <ming.lei at redhat.com>
---
 drivers/nvme/host/pci.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 4232192e10dd..d49b1a082983 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -3075,9 +3075,14 @@ static unsigned long check_vendor_combination_bug(struct pci_dev *pdev)
 static void nvme_async_probe(void *data, async_cookie_t cookie)
 {
 	struct nvme_dev *dev = data;
+	struct pci_dev *pdev = to_pci_dev(dev->dev);
 
+	pci_dev_lock(pdev);
+	nvme_reset_ctrl(&dev->ctrl);
 	flush_work(&dev->ctrl.reset_work);
 	flush_work(&dev->ctrl.scan_work);
+	pci_dev_unlock(pdev);
+
 	nvme_put_ctrl(&dev->ctrl);
 }
 
@@ -3154,7 +3159,6 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 	dev_info(dev->ctrl.device, "pci function %s\n", dev_name(&pdev->dev));
 
-	nvme_reset_ctrl(&dev->ctrl);
 	async_schedule(nvme_async_probe, dev);
 
 	return 0;
-- 
2.31.1