From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Thu, 24 Dec 2020 12:25:19 +0000 (-0500)
Subject: mm/filemap: Add folio_pos() and folio_file_pos()
X-Git-Tag: v6.6.17~9013^2~75
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=352b47a6984470954e1e262126b1da5312c40b09;p=platform%2Fkernel%2Flinux-rpi.git

mm/filemap: Add folio_pos() and folio_file_pos()

These are just wrappers around page_offset() and page_file_offset()
respectively.  No change to generated code.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: David Howells <dhowells@redhat.com>
---

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 95e83a9..3354117 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -561,6 +561,27 @@ static inline loff_t page_file_offset(struct page *page)
 	return ((loff_t)page_index(page)) << PAGE_SHIFT;
 }
 
+/**
+ * folio_pos - Returns the byte position of this folio in its file.
+ * @folio: The folio.
+ */
+static inline loff_t folio_pos(struct folio *folio)
+{
+	return page_offset(&folio->page);
+}
+
+/**
+ * folio_file_pos - Returns the byte position of this folio in its file.
+ * @folio: The folio.
+ *
+ * This differs from folio_pos() for folios which belong to a swap file.
+ * NFS is the only filesystem today which needs to use folio_file_pos().
+ */
+static inline loff_t folio_file_pos(struct folio *folio)
+{
+	return page_file_offset(&folio->page);
+}
+
 extern pgoff_t linear_hugepage_index(struct vm_area_struct *vma,
 				     unsigned long address);