filemap: Use a folio in filemap_map_pages

Saves 61 bytes due to fewer calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>

diff --git a/mm/filemap.c b/mm/filemap.c
index 14019070c98b51fdc641f3b08f390e69b69696d3..f595563057c3677ebb71add28231987566665821 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3227,7 +3227,7 @@ static bool filemap_map_pmd(struct vm_fault *vmf, struct page *page)
        return false;
 }
 
-static struct page *next_uptodate_page(struct folio *folio,
+static struct folio *next_uptodate_page(struct folio *folio,
                                       struct address_space *mapping,
                                       struct xa_state *xas, pgoff_t end_pgoff)
 {
@@ -3258,7 +3258,7 @@ static struct page *next_uptodate_page(struct folio *folio,
                max_idx = DIV_ROUND_UP(i_size_read(mapping->host), PAGE_SIZE);
                if (xas->xa_index >= max_idx)
                        goto unlock;
-               return &folio->page;
+               return folio;
 unlock:
                folio_unlock(folio);
 skip:
@@ -3268,7 +3268,7 @@ skip:
        return NULL;
 }
 
-static inline struct page *first_map_page(struct address_space *mapping,
+static inline struct folio *first_map_page(struct address_space *mapping,
                                          struct xa_state *xas,
                                          pgoff_t end_pgoff)
 {
@@ -3276,7 +3276,7 @@ static inline struct page *first_map_page(struct address_space *mapping,
                                  mapping, xas, end_pgoff);
 }
 
-static inline struct page *next_map_page(struct address_space *mapping,
+static inline struct folio *next_map_page(struct address_space *mapping,
                                         struct xa_state *xas,
                                         pgoff_t end_pgoff)
 {
@@ -3293,16 +3293,17 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf,
        pgoff_t last_pgoff = start_pgoff;
        unsigned long addr;
        XA_STATE(xas, &mapping->i_pages, start_pgoff);
-       struct page *head, *page;
+       struct folio *folio;
+       struct page *page;
        unsigned int mmap_miss = READ_ONCE(file->f_ra.mmap_miss);
        vm_fault_t ret = 0;
 
        rcu_read_lock();
-       head = first_map_page(mapping, &xas, end_pgoff);
-       if (!head)
+       folio = first_map_page(mapping, &xas, end_pgoff);
+       if (!folio)
                goto out;
 
-       if (filemap_map_pmd(vmf, head)) {
+       if (filemap_map_pmd(vmf, &folio->page)) {
                ret = VM_FAULT_NOPAGE;
                goto out;
        }
@@ -3310,7 +3311,7 @@ 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 {
-               page = find_subpage(head, xas.xa_index);
+               page = folio_file_page(folio, xas.xa_index);
                if (PageHWPoison(page))
                        goto unlock;
 
@@ -3331,12 +3332,12 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf,
                do_set_pte(vmf, page, addr);
                /* no need to invalidate: a not-present page won't be cached */
                update_mmu_cache(vma, addr, vmf->pte);
-               unlock_page(head);
+               folio_unlock(folio);
                continue;
 unlock:
-               unlock_page(head);
-               put_page(head);
-       } while ((head = next_map_page(mapping, &xas, end_pgoff)) != NULL);
+               folio_unlock(folio);
+               folio_put(folio);
+       } while ((folio = next_map_page(mapping, &xas, end_pgoff)) != NULL);
        pte_unmap_unlock(vmf->pte, vmf->ptl);
 out:
        rcu_read_unlock();