+ mm-convert-page_to_pgoff-to-page_pgoff.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm: convert page_to_pgoff() to page_pgoff()
has been added to the -mm mm-unstable branch.  Its filename is
     mm-convert-page_to_pgoff-to-page_pgoff.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-convert-page_to_pgoff-to-page_pgoff.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: mm: convert page_to_pgoff() to page_pgoff()
Date: Tue, 23 Jul 2024 16:34:58 +0100

Change the function signature to pass in the folio as all three
callers have it.  This removes a reference to page->index, which we're
trying to get rid of.  Also move page_pgoff() to mm/internal.h as
code outside mm has no business calling it.

Link: https://lkml.kernel.org/r/20240723153503.1669586-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/pagemap.h |   18 ------------------
 mm/internal.h           |    6 ++++++
 mm/memory-failure.c     |    4 ++--
 mm/rmap.c               |    2 +-
 4 files changed, 9 insertions(+), 21 deletions(-)

--- a/include/linux/pagemap.h~mm-convert-page_to_pgoff-to-page_pgoff
+++ a/include/linux/pagemap.h
@@ -914,24 +914,6 @@ static inline struct folio *read_mapping
 }
 
 /*
- * Get the offset in PAGE_SIZE (even for hugetlb pages).
- */
-static inline pgoff_t page_to_pgoff(struct page *page)
-{
-	struct page *head;
-
-	if (likely(!PageTransTail(page)))
-		return page->index;
-
-	head = compound_head(page);
-	/*
-	 *  We don't initialize ->index for tail pages: calculate based on
-	 *  head page
-	 */
-	return head->index + page - head;
-}
-
-/*
  * Return byte-offset into filesystem object for page.
  */
 static inline loff_t page_offset(struct page *page)
--- a/mm/internal.h~mm-convert-page_to_pgoff-to-page_pgoff
+++ a/mm/internal.h
@@ -893,6 +893,12 @@ void mlock_drain_remote(int cpu);
 
 extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
 
+static inline pgoff_t page_pgoff(const struct folio *folio,
+		const struct page *page)
+{
+	return folio->index + folio_page_idx(folio, page);
+}
+
 /**
  * vma_address - Find the virtual address a page range is mapped at
  * @vma: The vma which maps this object.
--- a/mm/memory-failure.c~mm-convert-page_to_pgoff-to-page_pgoff
+++ a/mm/memory-failure.c
@@ -617,7 +617,7 @@ static void collect_procs_anon(struct fo
 	if (av == NULL)	/* Not actually mapped anymore */
 		return;
 
-	pgoff = page_to_pgoff(page);
+	pgoff = page_pgoff(folio, page);
 	rcu_read_lock();
 	for_each_process(tsk) {
 		struct vm_area_struct *vma;
@@ -653,7 +653,7 @@ static void collect_procs_file(struct fo
 
 	i_mmap_lock_read(mapping);
 	rcu_read_lock();
-	pgoff = page_to_pgoff(page);
+	pgoff = page_pgoff(folio, page);
 	for_each_process(tsk) {
 		struct task_struct *t = task_early_kill(tsk, force_early);
 		unsigned long addr;
--- a/mm/rmap.c~mm-convert-page_to_pgoff-to-page_pgoff
+++ a/mm/rmap.c
@@ -1266,7 +1266,7 @@ static void __page_check_anon_rmap(struc
 	 */
 	VM_BUG_ON_FOLIO(folio_anon_vma(folio)->root != vma->anon_vma->root,
 			folio);
-	VM_BUG_ON_PAGE(page_to_pgoff(page) != linear_page_index(vma, address),
+	VM_BUG_ON_PAGE(page_pgoff(folio, page) != linear_page_index(vma, address),
 		       page);
 }
 
_

Patches currently in -mm which might be from willy@infradead.org are

bootmem-stop-using-page-index.patch
mm-constify-page_address_in_vma.patch
mm-convert-page_to_pgoff-to-page_pgoff.patch
mm-mass-constification-of-folio-page-pointers.patch
mm-remove-references-to-page-index-in-huge_memoryc.patch
mm-use-page-private-instead-of-page-index-in-percpu.patch