On Fri, Feb 03, 2023 at 09:16:33PM +0800, Yin Fengwei wrote:
> @@ -3378,45 +3425,18 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf,
> addr = vma->vm_start + ((start_pgoff - vma->vm_pgoff) << PAGE_SHIFT);
> vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, addr, &vmf->ptl);
> do {
> -again:
> - page = folio_file_page(folio, xas.xa_index);
> - if (PageHWPoison(page))
> - goto unlock;
> -
> - if (mmap_miss > 0)
> - mmap_miss--;
> + unsigned long end;
>
> addr += (xas.xa_index - last_pgoff) << PAGE_SHIFT;
> vmf->pte += xas.xa_index - last_pgoff;
> last_pgoff = xas.xa_index;
> + end = folio->index + folio_nr_pages(folio) - 1;
> + nr_pages = min(end, end_pgoff) - xas.xa_index + 1;
>
> - /*
> - * NOTE: If there're PTE markers, we'll leave them to be
> - * handled in the specific fault path, and it'll prohibit the
> - * fault-around logic.
> - */
> - if (!pte_none(*vmf->pte))
> - goto unlock;
> -
> - /* We're about to handle the fault */
> - if (vmf->address == addr)
> - ret = VM_FAULT_NOPAGE;
> + ret |= filemap_map_folio_range(vmf, folio,
> + xas.xa_index - folio->index, addr, nr_pages);
> + xas.xa_index = end;
IIRC, end here can be beyond end_pgoff. Can it cause an issue? I don't see
it, but just in case.
--
Kiryl Shutsemau / Kirill A. Shutemov
