mm/writeback: Add folio_mark_dirty()

Reimplement set_page_dirty() as a wrapper around folio_mark_dirty().
There is no change to filesystems as they were already being called
with the compound_head of the page being marked dirty.  We avoid
several calls to compound_head(), both statically (through
using folio_test_dirty() instead of PageDirty() and dynamically by
calling folio_mapping() instead of page_mapping().

Also return bool instead of int to show the range of values actually
returned, and add kernel-doc.

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 10ce5582d869..2c2b3917b5dc 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -77,3 +77,9 @@ bool set_page_writeback(struct page *page)
 	return folio_start_writeback(page_folio(page));
 }
 EXPORT_SYMBOL(set_page_writeback);
+
+bool set_page_dirty(struct page *page)
+{
+	return folio_mark_dirty(page_folio(page));
+}
+EXPORT_SYMBOL(set_page_dirty);