iomap: Add iomap_invalidate_folio

Keep iomap_invalidatepage around as a wrapper for use in address_space
operations.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

fs/iomap/buffered-io.c

@@ -479,23 +479,27 @@ iomap_releasepage(struct page *page, gfp_t gfp_mask)
 }
 EXPORT_SYMBOL_GPL(iomap_releasepage);
 
-void
-iomap_invalidatepage(struct page *page, unsigned int offset, unsigned int len)
+void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len)
 {
-	struct folio *folio = page_folio(page);
-
-	trace_iomap_invalidatepage(page->mapping->host, offset, len);
+	trace_iomap_invalidatepage(folio->mapping->host, offset, len);
 
 	/*
 	 * If we're invalidating the entire page, clear the dirty state from it
 	 * and release it to avoid unnecessary buildup of the LRU.
 	 */
-	if (offset == 0 && len == PAGE_SIZE) {
-		WARN_ON_ONCE(PageWriteback(page));
-		cancel_dirty_page(page);
+	if (offset == 0 && len == folio_size(folio)) {
+		WARN_ON_ONCE(folio_test_writeback(folio));
+		folio_cancel_dirty(folio);
 		iomap_page_release(folio);
 	}
 }
+EXPORT_SYMBOL_GPL(iomap_invalidate_folio);
+
+void iomap_invalidatepage(struct page *page, unsigned int offset,
+		unsigned int len)
+{
+	iomap_invalidate_folio(page_folio(page), offset, len);
+}
 EXPORT_SYMBOL_GPL(iomap_invalidatepage);
 
 #ifdef CONFIG_MIGRATION

include/linux/iomap.h

@@ -225,6 +225,7 @@ void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops);
 int iomap_is_partially_uptodate(struct page *page, unsigned long from,
 		unsigned long count);
 int iomap_releasepage(struct page *page, gfp_t gfp_mask);
+void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len);
 void iomap_invalidatepage(struct page *page, unsigned int offset,
 		unsigned int len);
 #ifdef CONFIG_MIGRATION