mm/writeback: Add folio_clear_dirty_for_io()

Transform clear_page_dirty_for_io() into folio_clear_dirty_for_io()
and add a compatibility wrapper.  Also move the declaration to pagemap.h
as this is page cache functionality that doesn't need to be used by the
rest of the kernel.

Increases the size of the kernel by 79 bytes.  While we remove a few
calls to compound_head(), we add a call to folio_nr_pages() to get the
stats correct for the eventual support of multi-page folios.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>

1 files changed, 6 insertions, 0 deletions

diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index dad962b920e5..39f5a8d963b1 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -89,3 +89,9 @@ int __set_page_dirty_nobuffers(struct page *page)
 	return filemap_dirty_folio(page_mapping(page), page_folio(page));
 }
 EXPORT_SYMBOL(__set_page_dirty_nobuffers);
+
+bool clear_page_dirty_for_io(struct page *page)
+{
+	return folio_clear_dirty_for_io(page_folio(page));
+}
+EXPORT_SYMBOL(clear_page_dirty_for_io);