Patch "memory-failure: use a folio in me_huge_page()" has been added to the 6.6-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    memory-failure: use a folio in me_huge_page()

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     memory-failure-use-a-folio-in-me_huge_page.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit ca963e2fedd01fd9b6180487a9c2b85fd5db4160
Author: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Date:   Fri Nov 17 16:14:45 2023 +0000

    memory-failure: use a folio in me_huge_page()
    
    [ Upstream commit b6fd410c32f1a66a52a42d6aae1ab7b011b74547 ]
    
    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@xxxxxxxxxxxxx
    Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
    Cc: Naoya Horiguchi <naoya.horiguchi@xxxxxxx>
    Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
    Stable-dep-of: 8cf360b9d6a8 ("mm/memory-failure: fix handling of dissolved but not taken off from buddy pages")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 5378edad9df8f..9c27ec0a27a30 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1193,25 +1193,25 @@ 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;