[v13,14/32] mm/filemap: Add folio_next_index()

Commit Message

Matthew Wilcox July 12, 2021, 7:01 p.m. UTC

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) <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
Acked-by: Jeff Layton <[e-mail]>
Acked-by: Kirill A. Shutemov <[e-mail]>
Acked-by: Vlastimil Babka <[e-mail]>
Reviewed-by: William Kucharski <[e-mail]>
Reviewed-by: David Howells <[e-mail]>
---
 include/linux/pagemap.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

Patch

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 8cc67ddb47d4..aac447fbaddd 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -406,6 +406,17 @@  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.