[PATCH 3/6] xfsdocs: update the on-disk format with changes for Linux 4.5

[Darrick J. Wong]

Signed-off-by: Darrick J. Wong <darrick.wong at oracle.com>
---
 .../XFS_Filesystem_Structure/ondisk_inode.asciidoc |   19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)


diff --git a/design/XFS_Filesystem_Structure/ondisk_inode.asciidoc b/design/XFS_Filesystem_Structure/ondisk_inode.asciidoc
index 4aabc55..dc1fad2 100644
--- a/design/XFS_Filesystem_Structure/ondisk_inode.asciidoc
+++ b/design/XFS_Filesystem_Structure/ondisk_inode.asciidoc
@@ -66,9 +66,10 @@ of the literal area and +di_forkoff+. The attribute fork is located between
 [[Inode_Core]]
 == Inode Core
 
-The inode's core is 96 bytes in size and contains information about the file
-itself including most stat data information about data and attribute forks after
-the core within the inode. It uses the following structure:
+The inode's core is 96 bytes on a V4 filesystem and 176 bytes on a V5
+filesystem.  It contains information about the file itself including most stat
+data information about data and attribute forks after the core within the
+inode. It uses the following structure:
 
 [source, c]
 ----
@@ -313,8 +314,16 @@ Counts the number of changes made to the attributes in this inode.
 Log sequence number of the last inode write.
 
 *di_flags2*::
-Specifies extended flags associated with a v3 inode.  There are no flags defined
-currently.
+Specifies extended flags associated with a v3 inode.
+
+.Version 3 Inode flags
+[options="header"]
+|=====
+| Flag				| Description
+| +XFS_DIFLAG2_DAX+		|
+For a file, enable DAX to increase performance on persistent-memory storage.
+If set on a directory, files created in the directory will inherit this flag.
+|=====
 
 *di_pad2*::
 Padding for future expansion of the inode.