f2fs: get out of a repeat loop when getting a locked data page

commit d2d9bb3 upstream.

https://bugzilla.kernel.org/show_bug.cgi?id=216050

Somehow we're getting a page which has a different mapping.
Let's avoid the infinite loop.

Cc: <stable@vger.kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/f2fs/data.c

@@ -1389,18 +1389,14 @@ struct page *f2fs_get_lock_data_page(struct inode *inode, pgoff_t index,
 {
 	struct address_space *mapping = inode->i_mapping;
 	struct page *page;
-repeat:
+
 	page = f2fs_get_read_data_page(inode, index, 0, for_write, NULL);
 	if (IS_ERR(page))
 		return page;
 
 	/* wait for read completion */
 	lock_page(page);
-	if (unlikely(page->mapping != mapping)) {
-		f2fs_put_page(page, 1);
-		goto repeat;
-	}
-	if (unlikely(!PageUptodate(page))) {
+	if (unlikely(page->mapping != mapping || !PageUptodate(page))) {
 		f2fs_put_page(page, 1);
 		return ERR_PTR(-EIO);
 	}