memory-failure: use a folio in me_huge_page()

This function was already explicitly calling compound_head();
unfortunately the compiler can't know that and elide the redundant calls
to compound_head() buried in page_mapping(), unlock_page(), etc.  Switch
to using a folio, which does let us elide these calls.

Link: https://lkml.kernel.org/r/20231117161447.2461643-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index e73f2047ffcbedc02fc0ed7252ed4cee901158aa..d97d247c0224fc61a2dd93a437fcfde2fcf5a716 100644 (file)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1182,25 +1182,25 @@ static int me_swapcache_clean(struct page_state *ps, struct page *p)
  */
 static int me_huge_page(struct page_state *ps, struct page *p)
 {
+       struct folio *folio = page_folio(p);
        int res;
-       struct page *hpage = compound_head(p);
        struct address_space *mapping;
        bool extra_pins = false;
 
-       mapping = page_mapping(hpage);
+       mapping = folio_mapping(folio);
        if (mapping) {
-               res = truncate_error_page(hpage, page_to_pfn(p), mapping);
+               res = truncate_error_page(&folio->page, page_to_pfn(p), mapping);
                /* The page is kept in page cache. */
                extra_pins = true;
-               unlock_page(hpage);
+               folio_unlock(folio);
        } else {
-               unlock_page(hpage);
+               folio_unlock(folio);
                /*
                 * migration entry prevents later access on error hugepage,
                 * so we can free and dissolve it into buddy to save healthy
                 * subpages.
                 */
-               put_page(hpage);
+               folio_put(folio);
                if (__page_handle_poison(p) >= 0) {
                        page_ref_inc(p);
                        res = MF_RECOVERED;