mm: convert do_anonymous_page() to use a folio

Removes six calls to compound_head(); some inline and some external.

Link: https://lkml.kernel.org/r/20230116191813.2145215-3-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memory.c

@@ -3996,7 +3996,6 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
 static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 {
 	struct vm_area_struct *vma = vmf->vma;
-	struct page *page;
 	struct folio *folio;
 	vm_fault_t ret = 0;
 	pte_t entry;
@@ -4051,19 +4050,18 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	if (!folio)
 		goto oom;
 
-	page = &folio->page;
 	if (mem_cgroup_charge(folio, vma->vm_mm, GFP_KERNEL))
 		goto oom_free_page;
-	cgroup_throttle_swaprate(page, GFP_KERNEL);
+	cgroup_throttle_swaprate(&folio->page, GFP_KERNEL);
 
 	/*
-	 * The memory barrier inside __SetPageUptodate makes sure that
+	 * The memory barrier inside __folio_mark_uptodate makes sure that
 	 * preceding stores to the page contents become visible before
 	 * the set_pte_at() write.
 	 */
-	__SetPageUptodate(page);
+	__folio_mark_uptodate(folio);
 
-	entry = mk_pte(page, vma->vm_page_prot);
+	entry = mk_pte(&folio->page, vma->vm_page_prot);
 	entry = pte_sw_mkyoung(entry);
 	if (vma->vm_flags & VM_WRITE)
 		entry = pte_mkwrite(pte_mkdirty(entry));
@@ -4082,13 +4080,13 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	/* Deliver the page fault to userland, check inside PT lock */
 	if (userfaultfd_missing(vma)) {
 		pte_unmap_unlock(vmf->pte, vmf->ptl);
-		put_page(page);
+		folio_put(folio);
 		return handle_userfault(vmf, VM_UFFD_MISSING);
 	}
 
 	inc_mm_counter(vma->vm_mm, MM_ANONPAGES);
-	page_add_new_anon_rmap(page, vma, vmf->address);
-	lru_cache_add_inactive_or_unevictable(page, vma);
+	folio_add_new_anon_rmap(folio, vma, vmf->address);
+	folio_add_lru_vma(folio, vma);
 setpte:
 	set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry);
 
@@ -4098,10 +4096,10 @@ static vm_fault_t do_anonymous_page(struct vm_fault *vmf)
 	pte_unmap_unlock(vmf->pte, vmf->ptl);
 	return ret;
 release:
-	put_page(page);
+	folio_put(folio);
 	goto unlock;
 oom_free_page:
-	put_page(page);
+	folio_put(folio);
 oom:
 	return VM_FAULT_OOM;
 }