When we unload pci-hyperv, the host doesn't send us a PCI_EJECT message. In this case we also need to make sure the sysfs pci slot directory is removed, otherwise "cat /sys/bus/pci/slots/2/address" will trigger "BUG: unable to handle kernel paging request" (I noticed the issue when systemd-dev crashed for me when I unloaded the driver). And, if we unload/reload the driver several times, we'll have multiple pci slot directories in /sys/bus/pci/slots/ like this:

root@localhost:~# ls -rtl /sys/bus/pci/slots/ total 0 drwxr-xr-x 2 root root 0 Feb 7 10:49 2 drwxr-xr-x 2 root root 0 Feb 7 10:49 2-1 drwxr-xr-x 2 root root 0 Feb 7 10:51 2-2

The patch adds the missing code.

Fixes: a15f2c08c708 ("PCI: hv: support reporting serial number as slot information") Signed-off-by: Dexuan Cui decui@microsoft.com Acked-by: Stephen Hemminger sthemmin@microsoft.com Cc: stable@vger.kernel.org --- drivers/pci/controller/pci-hyperv.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c index 30f16b882746..b489412e3502 100644 --- a/drivers/pci/controller/pci-hyperv.c +++ b/drivers/pci/controller/pci-hyperv.c @@ -1486,6 +1486,21 @@ static void hv_pci_assign_slots(struct hv_pcibus_device *hbus) } }

+/* + * Remove entries in sysfs pci slot directory. + */ +static void hv_pci_remove_slots(struct hv_pcibus_device *hbus) +{ + struct hv_pci_dev *hpdev; + + list_for_each_entry(hpdev, &hbus->children, list_entry) { + if (!hpdev->pci_slot) + continue; + pci_destroy_slot(hpdev->pci_slot); + hpdev->pci_slot = NULL; + } +} + /** * create_root_hv_pci_bus() - Expose a new root PCI bus * @hbus: Root PCI bus, as understood by this driver @@ -2680,6 +2695,7 @@ static int hv_pci_remove(struct hv_device *hdev) pci_lock_rescan_remove(); pci_stop_root_bus(hbus->pci_bus); pci_remove_root_bus(hbus->pci_bus); + hv_pci_remove_slots(hbus); pci_unlock_rescan_remove(); hbus->state = hv_pcibus_removed; }