Re: FAILED: patch "[PATCH] PCI: hv: Add hv_pci_remove_slots() when we unload the driver" failed to apply to 4.14-stable tree

[Sasha Levin <sashal@kernel.org>]

On Wed, May 15, 2019 at 11:19:40PM +0000, Dexuan Cui wrote:
>> From: gregkh@linuxfoundation.org <gregkh@linuxfoundation.org>
>> Sent: Wednesday, May 15, 2019 1:35 AM
>> To: Dexuan Cui <decui@microsoft.com>; lorenzo.pieralisi@arm.com; Michael
>> Kelley <mikelley@microsoft.com>; Stephen Hemminger
>> <sthemmin@microsoft.com>
>> Cc: stable@vger.kernel.org
>> Subject: FAILED: patch "[PATCH] PCI: hv: Add hv_pci_remove_slots() when we
>> unload the driver" failed to apply to 4.14-stable tree
>>
>>
>> The patch below does not apply to the 4.14-stable tree.
>> If someone wants it applied there, or to any other stable or longterm
>> tree, then please email the backport, including the original git commit
>> id to <stable@vger.kernel.org>.
>>
>> thanks,
>>
>> greg k-h
>>
>> ------------------ original commit in Linus's tree ------------------
>>
>> From 15becc2b56c6eda3d9bf5ae993bafd5661c1fad1 Mon Sep 17 00:00:00
>> 2001
>> From: Dexuan Cui <decui@microsoft.com>
>> Date: Mon, 4 Mar 2019 21:34:48 +0000
>> Subject: [PATCH] PCI: hv: Add hv_pci_remove_slots() when we unload the
>> driver
>>
>> When we unload the pci-hyperv host controller driver, the host does not
>> send us a PCI_EJECT message.
>>
>> In this case we also need to make sure the sysfs PCI slot directory is
>> removed, otherwise a command on a slot file eg:
>>
>> "cat /sys/bus/pci/slots/2/address"
>>
>> will trigger a
>>
>> "BUG: unable to handle kernel paging request"
>>
>> and, if we unload/reload the driver several times we would end up with
>> stale slot entries in PCI slot directories in /sys/bus/pci/slots/
>>
>> 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
>>
>> Add the missing code to remove the PCI slot and fix the current
>> behaviour.
>>
>> Fixes: a15f2c08c708 ("PCI: hv: support reporting serial number as slot
>> information")
>> Signed-off-by: Dexuan Cui <decui@microsoft.com>
>> [lorenzo.pieralisi@arm.com: reformatted the log]
>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Reviewed-by: Stephen Hemminger <sthemmin@microsoft.com>
>> Reviewed-by: Michael Kelley <mikelley@microsoft.com>
>> Cc: stable@vger.kernel.org
>>
>> 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;
>>  	}
>
>Hi,
>I backported the patch for linux-4.14.y.
>
>Please use the attached patch, which is [PATCH 2/3]
>
>Thanks,
>-- Dexuan

Queued for 4.14, thank you.

--
Thanks,
Sasha