[PATCH 01/35] nilfs2: Add nilfs_end_folio_io()

["Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>]

This is the folio counterpart of the existing nilfs_end_page_io()
which is retained as a wrapper of nilfs_end_folio_io().  Replaces
nine hidden calls to compound_head() with one.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 fs/nilfs2/segment.c | 36 ++++++++++++++++++++++--------------
 1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
index 55e31cc903d1..1df03d0895be 100644
--- a/fs/nilfs2/segment.c
+++ b/fs/nilfs2/segment.c
@@ -1739,17 +1739,18 @@ static int nilfs_segctor_write(struct nilfs_sc_info *sci,
 	return ret;
 }
 
-static void nilfs_end_page_io(struct page *page, int err)
+static void nilfs_end_folio_io(struct folio *folio, int err)
 {
-	if (!page)
+	if (!folio)
 		return;
 
-	if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) {
+	if (buffer_nilfs_node(folio_buffers(folio)) &&
+			!folio_test_writeback(folio)) {
 		/*
 		 * For b-tree node pages, this function may be called twice
 		 * or more because they might be split in a segment.
 		 */
-		if (PageDirty(page)) {
+		if (folio_test_dirty(folio)) {
 			/*
 			 * For pages holding split b-tree node buffers, dirty
 			 * flag on the buffers may be cleared discretely.
@@ -1757,24 +1758,31 @@ static void nilfs_end_page_io(struct page *page, int err)
 			 * remaining buffers, and it must be cancelled if
 			 * all the buffers get cleaned later.
 			 */
-			lock_page(page);
-			if (nilfs_page_buffers_clean(page))
-				__nilfs_clear_page_dirty(page);
-			unlock_page(page);
+			folio_lock(folio);
+			if (nilfs_page_buffers_clean(&folio->page))
+				__nilfs_clear_page_dirty(&folio->page);
+			folio_unlock(folio);
 		}
 		return;
 	}
 
 	if (!err) {
-		if (!nilfs_page_buffers_clean(page))
-			__set_page_dirty_nobuffers(page);
-		ClearPageError(page);
+		if (!nilfs_page_buffers_clean(&folio->page))
+			filemap_dirty_folio(folio->mapping, folio);
+		folio_clear_error(folio);
 	} else {
-		__set_page_dirty_nobuffers(page);
-		SetPageError(page);
+		filemap_dirty_folio(folio->mapping, folio);
+		folio_set_error(folio);
 	}
 
-	end_page_writeback(page);
+	folio_end_writeback(folio);
+}
+
+static void nilfs_end_page_io(struct page *page, int err)
+{
+	if (!page)
+		return;
+	nilfs_end_folio_io(page_folio(page), err);
 }
 
 static void nilfs_abort_logs(struct list_head *logs, int err)
-- 
2.42.0