Commit 595af4c9 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

rmap: convert page_move_anon_rmap() to use a folio 

Removes one call to compound_head() and a reference to page->mapping.

Link: https://lkml.kernel.org/r/20220902194653.1739778-50-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 3b344157

mm/rmap.c

+6 −8
Original line number Diff line number Diff line
@@ -1099,22 +1099,20 @@ int pfn_mkclean_range(unsigned long pfn, unsigned long nr_pages, pgoff_t pgoff, 
 */

void page_move_anon_rmap(struct page *page, struct vm_area_struct *vma)

{

	struct anon_vma *anon_vma = vma->anon_vma;

	struct page *subpage = page;



	page = compound_head(page);

	void *anon_vma = vma->anon_vma;

	struct folio *folio = page_folio(page);



	VM_BUG_ON_PAGE(!PageLocked(page), page);

	VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);

	VM_BUG_ON_VMA(!anon_vma, vma);



	anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;

	anon_vma += PAGE_MAPPING_ANON;

	/*

	 * Ensure that anon_vma and the PAGE_MAPPING_ANON bit are written

	 * simultaneously, so a concurrent reader (eg folio_referenced()'s

	 * folio_test_anon()) will not see one without the other.

	 */

	WRITE_ONCE(page->mapping, (struct address_space *) anon_vma);

	SetPageAnonExclusive(subpage);

	WRITE_ONCE(folio->mapping, anon_vma);

	SetPageAnonExclusive(page);

}



/**