Re: [PATCH 1/2] pci: fix slot trylock error handling

[<dan.j.williams@intel.com>]

Keith Busch wrote:
> From: Keith Busch <kbusch@kernel.org>
> 
> The device lock isn't held if pci_bus_trylock() fails, so the code had
> been attempting to improperly unlock it.
> 
> Fixes: a4e772898f8bf2 ("PCI: Add missing bridge lock to pci_bus_lock()")
> Signed-off-by: Keith Busch <kbusch@kernel.org>
> ---
>  drivers/pci/pci.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 72d88ea95f3cc..3378221c5723a 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -5494,10 +5494,8 @@ static int pci_slot_trylock(struct pci_slot *slot)
>  		if (!dev->slot || dev->slot != slot)
>  			continue;
>  		if (dev->subordinate) {
> -			if (!pci_bus_trylock(dev->subordinate)) {
> -				pci_dev_unlock(dev);
> +			if (!pci_bus_trylock(dev->subordinate))
>  				goto unlock;
> -			}
>  		} else if (!pci_dev_trylock(dev))
>  			goto unlock;

This looks right and the original patch missed fixing up this inner
unlock when it moved the @dev lock to be conditional for non-bridge
devices.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>