From 0520a938e11c34a5ffc422b9316b85e294b0fbb2 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Sun, 11 Sep 2016 12:58:59 -0300
Subject: Linux-libre 4.7.3-gnu

---
 mm/readahead.c | 9 +++++++++
 1 file changed, 9 insertions(+)

(limited to 'mm/readahead.c')

diff --git a/mm/readahead.c b/mm/readahead.c
index 40be3ae0a..7f9f8c346 100644
--- a/mm/readahead.c
+++ b/mm/readahead.c
@@ -8,6 +8,7 @@
  */
 
 #include <linux/kernel.h>
+#include <linux/dax.h>
 #include <linux/gfp.h>
 #include <linux/export.h>
 #include <linux/blkdev.h>
@@ -545,6 +546,14 @@ do_readahead(struct address_space *mapping, struct file *filp,
 	if (!mapping || !mapping->a_ops)
 		return -EINVAL;
 
+	/*
+	 * Readahead doesn't make sense for DAX inodes, but we don't want it
+	 * to report a failure either.  Instead, we just return success and
+	 * don't do any work.
+	 */
+	if (dax_mapping(mapping))
+		return 0;
+
 	return force_page_cache_readahead(mapping, filp, index, nr);
 }
 
-- 
cgit v1.2.3-54-g00ecf