mm/filemap: Add folio_next_index()

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

No changes to generated code.

Signed-off-by: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Acked-by: Jeff Layton <[email protected]>
Acked-by: Kirill A. Shutemov <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Reviewed-by: William Kucharski <[email protected]>
Reviewed-by: David Howells <[email protected]>
Acked-by: Mike Rapoport <[email protected]>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index e7b46223239a..95e83a9e73c7 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -407,6 +407,17 @@ static inline pgoff_t folio_index(struct folio *folio)
 }
 
 /**
+ * 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.
  * @index: The index we want to look up.