[PATCH v8 12/31] mm/filemap: Add folio_next_index

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

This helper returns the page index of the next folio in the file (ie
the end of this folio, plus one).

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
---
 include/linux/pagemap.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 58c9b98604d0..5301131cc5b3 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -482,6 +482,17 @@ static inline pgoff_t folio_index(struct folio *folio)
         return folio->index;
 }
 
+/**
+ * folio_next_index - Get the index of the next folio.
+ * @folio: The current folio.
+ *
+ * Return: The index of the folio which follows this folio in the file.
+ */
+static inline pgoff_t folio_next_index(struct folio *folio)
+{
+	return folio->index + folio_nr_pages(folio);
+}
+
 /**
  * folio_file_page - The page for a particular index.
  * @folio: The folio which contains this index.
-- 
2.30.2