On Fri, Oct 6, 2023 at 12:53 PM Matthew Wilcox (Oracle)
<willy@xxxxxxxxxxxxx> wrote:
>
> I think this is a pretty rare occurrence, but for consistency handle
> faults with the VMA lock held the same way that we handle other
> faults with the VMA lock held.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Reviewed-by: Suren Baghdasaryan <surenb@xxxxxxxxxx>
> ---
> mm/memory.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/mm/memory.c b/mm/memory.c
> index e615afd28db2..3d1bc622e344 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -3301,10 +3301,9 @@ static vm_fault_t wp_pfn_shared(struct vm_fault *vmf)
> vm_fault_t ret;
>
> pte_unmap_unlock(vmf->pte, vmf->ptl);
> - if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
> - vma_end_read(vmf->vma);
> - return VM_FAULT_RETRY;
> - }
> + ret = vmf_can_call_fault(vmf);
> + if (ret)
> + return ret;
>
> vmf->flags |= FAULT_FLAG_MKWRITE;
> ret = vma->vm_ops->pfn_mkwrite(vmf);
> @@ -3328,10 +3327,10 @@ static vm_fault_t wp_page_shared(struct vm_fault *vmf, struct folio *folio)
> vm_fault_t tmp;
>
> pte_unmap_unlock(vmf->pte, vmf->ptl);
> - if (vmf->flags & FAULT_FLAG_VMA_LOCK) {
> + tmp = vmf_can_call_fault(vmf);
> + if (tmp) {
> folio_put(folio);
> - vma_end_read(vmf->vma);
> - return VM_FAULT_RETRY;
> + return tmp;
> }
>
> tmp = do_page_mkwrite(vmf, folio);
> --
> 2.40.1
>
