[PATCH] xfs: document dax mount option

[Eric Sandeen <sandeen@xxxxxxxxxx>]

Add dax to the list of mount options in xfs.txt.

Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---

diff --git a/Documentation/filesystems/xfs.txt 
b/Documentation/filesystems/xfs.txt
index 8146e9f..e7e935d 100644
--- a/Documentation/filesystems/xfs.txt
+++ b/Documentation/filesystems/xfs.txt
@@ -58,6 +58,11 @@ default behaviour.
        This allows for drive level write caching to be enabled, for
        devices that support write barriers.
 
+  dax
+       Use direct access (no page cache) for block devices which are
+       memory-like, performing reads and writes directly to the storage
+       device.  See Documentation/filesystems/dax.txt.
+
   discard
   nodiscard (*)
        Enable/disable the issuing of commands to let the block