On 04/16/2018 09:14 AM, Dan Williams wrote:
> On Sat, Apr 14, 2018 at 8:50 AM, Souptick Joarder <jrdr.linux@xxxxxxxxx> wrote:
>> Use new return type vm_fault_t for fault and
>> huge_fault handler.
>>
>> Signed-off-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
>> Reviewed-by: Matthew Wilcox <mawilcox@xxxxxxxxxxxxx>
>> ---
>> drivers/dax/device.c | 26 +++++++++++---------------
>> 1 file changed, 11 insertions(+), 15 deletions(-)
>>
>> diff --git a/drivers/dax/device.c b/drivers/dax/device.c
>> index 2137dbc..a122701 100644
>> --- a/drivers/dax/device.c
>> +++ b/drivers/dax/device.c
>> @@ -243,11 +243,11 @@ __weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
>> return -1;
>> }
>>
>> -static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
>> +static vm_fault_t __dev_dax_pte_fault(struct dev_dax *dev_dax,
>> + struct vm_fault *vmf)
>> {
>> struct device *dev = &dev_dax->dev;
>> struct dax_region *dax_region;
>> - int rc = VM_FAULT_SIGBUS;
>> phys_addr_t phys;
>> pfn_t pfn;
>> unsigned int fault_size = PAGE_SIZE;
>> @@ -274,17 +274,11 @@ static int __dev_dax_pte_fault(struct dev_dax *dev_dax, struct vm_fault *vmf)
>>
>> pfn = phys_to_pfn_t(phys, dax_region->pfn_flags);
>>
>> - rc = vm_insert_mixed(vmf->vma, vmf->address, pfn);
>> -
>> - if (rc == -ENOMEM)
>> - return VM_FAULT_OOM;
>> - if (rc < 0 && rc != -EBUSY)
>> - return VM_FAULT_SIGBUS;
>> -
>> - return VM_FAULT_NOPAGE;
>> + return vmf_insert_mixed(vmf->vma, vmf->address, pfn);
>
> Ugh, so this change to vmf_insert_mixed() went upstream without fixing
> the users? This changelog is now misleading as it does not mention
> that is now an urgent standalone fix. On first read I assumed this was
> part of a wider effort for 4.18.
>
> Grumble, we'll get this applied with a 'Fixes: 1c8f422059ae ("mm:
> change return type to vm_fault_t")' tag.
>
Thanks for that explanation. The patch description is missing any kind
of "why" (justification).
--
~Randy
