befs: Convert befs_symlink_read_folio() to use a folio

This is a straightforward conversion from the page APIs to the folio
APIs.  Symlinks are not allowed to be larger than PAGE_SIZE, so there
is little work to do here.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

fs/befs/linuxvfs.c

@@ -108,8 +108,7 @@ static const struct export_operations befs_export_operations = {
  * passes it the address of befs_get_block, for mapping file
  * positions to disk blocks.
  */
-static int
-befs_read_folio(struct file *file, struct folio *folio)
+static int befs_read_folio(struct file *file, struct folio *folio)
 {
 	return block_read_full_folio(folio, befs_get_block);
 }
@@ -470,13 +469,12 @@ befs_destroy_inodecache(void)
  */
 static int befs_symlink_read_folio(struct file *unused, struct folio *folio)
 {
-	struct page *page = &folio->page;
-	struct inode *inode = page->mapping->host;
+	struct inode *inode = folio->mapping->host;
 	struct super_block *sb = inode->i_sb;
 	struct befs_inode_info *befs_ino = BEFS_I(inode);
 	befs_data_stream *data = &befs_ino->i_data.ds;
 	befs_off_t len = data->size;
-	char *link = page_address(page);
+	char *link = folio_address(folio);
 
 	if (len == 0 || len > PAGE_SIZE) {
 		befs_error(sb, "Long symlink with illegal length");
@@ -489,12 +487,12 @@ static int befs_symlink_read_folio(struct file *unused, struct folio *folio)
 		goto fail;
 	}
 	link[len - 1] = '\0';
-	SetPageUptodate(page);
-	unlock_page(page);
+	folio_mark_uptodate(folio);
+	folio_unlock(folio);
 	return 0;
 fail:
-	SetPageError(page);
-	unlock_page(page);
+	folio_set_error(folio);
+	folio_unlock(folio);
 	return -EIO;
 }