+ struct mm_struct *mm = vmf->vma->vm_mm;
+
+ /* Huge page is mapped? No need to proceed. */
+ if (pmd_trans_huge(*vmf->pmd)) {
+ unlock_page(page);
+ put_page(page);
+ return true;
+ }
+
+ if (pmd_none(*vmf->pmd) && PageTransHuge(page)) {
+ vm_fault_t ret = do_set_pmd(vmf, page);
+ if (!ret) {
+ /* The page is mapped successfully, reference consumed. */
+ unlock_page(page);
+ return true;
+ }
+ }
+
+ if (pmd_none(*vmf->pmd)) {
+ vmf->ptl = pmd_lock(mm, vmf->pmd);
+ if (likely(pmd_none(*vmf->pmd))) {
+ mm_inc_nr_ptes(mm);
+ pmd_populate(mm, vmf->pmd, vmf->prealloc_pte);
+ vmf->prealloc_pte = NULL;
+ }
+ spin_unlock(vmf->ptl);
+ }
+
+ /* See comment in handle_pte_fault() */
+ if (pmd_devmap_trans_unstable(vmf->pmd)) {
+ unlock_page(page);
+ put_page(page);
+ return true;
+ }
+
+ return false;
+}
+
+static struct page *next_uptodate_page(struct page *page,
+ struct address_space *mapping,
+ struct xa_state *xas, pgoff_t end_pgoff)
+{
+ unsigned long max_idx;
+
+ do {
+ if (!page)
+ return NULL;
+ if (xas_retry(xas, page))
+ continue;
+ if (xa_is_value(page))
+ continue;
+ if (PageLocked(page))
+ continue;
+ if (!page_cache_get_speculative(page))
+ continue;
+ /* Has the page moved or been split? */
+ if (unlikely(page != xas_reload(xas)))
+ goto skip;
+ if (!PageUptodate(page) || PageReadahead(page))
+ goto skip;
+ if (PageHWPoison(page))
+ goto skip;
+ if (!trylock_page(page))
+ goto skip;
+ if (page->mapping != mapping)
+ goto unlock;
+ if (!PageUptodate(page))
+ goto unlock;
+ max_idx = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE);
+ if (xas->xa_index >= max_idx)
+ goto unlock;
+ return page;
+unlock:
+ unlock_page(page);
+skip:
+ put_page(page);
+ } while ((page = xas_next_entry(xas, end_pgoff)) != NULL);
+
+ return NULL;
+}
+
+static inline struct page *first_map_page(struct address_space *mapping,
+ struct xa_state *xas,
+ pgoff_t end_pgoff)
+{
+ return next_uptodate_page(xas_find(xas, end_pgoff),
+ mapping, xas, end_pgoff);
+}
+
+static inline struct page *next_map_page(struct address_space *mapping,
+ struct xa_state *xas,
+ pgoff_t end_pgoff)
+{
+ return next_uptodate_page(xas_next_entry(xas, end_pgoff),
+ mapping, xas, end_pgoff);
+}
+
+vm_fault_t filemap_map_pages(struct vm_fault *vmf,
+ pgoff_t start_pgoff, pgoff_t end_pgoff)
+{
+ struct vm_area_struct *vma = vmf->vma;
+ struct file *file = vma->vm_file;