From 2397f999313713bb687d5a7aa8c60b098e51d6f3 Mon Sep 17 00:00:00 2001
From: Andrew Price <anprice@redhat.com>
Date: May 25 2016 15:04:37 +0000
Subject: gfs2-utils: Add a check for the de_rahead field


gfs2_dirent.de_rahead first appeared in Linux 3.15. Support prior
versions by checking for de_rahead and using it conditionally.

Signed-off-by: Andrew Price <anprice@redhat.com>

---

diff --git a/configure.ac b/configure.ac
index 35cafe6..a5418aa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -125,6 +125,8 @@ AC_CHECK_HEADER([linux/gfs2_ondisk.h], [], [AC_MSG_ERROR([Unable to find linux/g
 AC_CHECK_MEMBER([struct gfs2_sb.sb_uuid], [], [], [[#include <linux/gfs2_ondisk.h>]])
 AC_CHECK_MEMBER([struct gfs2_leaf.lf_inode],[AC_DEFINE([GFS2_HAS_LEAF_HINTS],[],[Leaf block hints])],
                 [], [[#include <linux/gfs2_ondisk.h>]])
+AC_CHECK_MEMBER([struct gfs2_dirent.de_rahead],[AC_DEFINE([GFS2_HAS_DE_RAHEAD],[],[Dirent readahead field])],
+                [], [[#include <linux/gfs2_ondisk.h>]])
 
 # *FLAGS handling
 ENV_CFLAGS="$CFLAGS"
diff --git a/gfs2/edit/extended.c b/gfs2/edit/extended.c
index b1826a1..a13827e 100644
--- a/gfs2/edit/extended.c
+++ b/gfs2/edit/extended.c
@@ -349,7 +349,12 @@ static int display_leaf(struct iinfo *ind)
 				   ind->ii[0].dirent[d].block,
 				   ind->ii[0].dirent[d].dirent.de_inum.no_formal_ino,
 				   ind->ii[0].dirent[d].block,
-				   (unsigned int)ind->ii[0].dirent[d].dirent.de_rahead);
+#ifdef GFS2_HAS_DE_RAHEAD
+				   (unsigned int)ind->ii[0].dirent[d].dirent.de_rahead
+#else
+				   0
+#endif
+			);
 		}
 		print_inode_type(ind->ii[0].dirent[d].dirent.de_type);
 		print_gfs2(" %s", ind->ii[0].dirent[d].filename);
diff --git a/gfs2/libgfs2/meta.c b/gfs2/libgfs2/meta.c
index 70daec4..4f43af5 100644
--- a/gfs2/libgfs2/meta.c
+++ b/gfs2/libgfs2/meta.c
@@ -428,8 +428,12 @@ F(de_hash, .flags = LGFS2_MFF_CHECK)
 F(de_rec_len, .flags = LGFS2_MFF_BYTES)
 F(de_name_len, .flags = LGFS2_MFF_BYTES)
 F(de_type)
+#ifdef GFS2_HAS_DE_RAHEAD
 F(de_rahead)
+RF(__pad2)
+#else
 RF(__pad)
+#endif
 };
 
 #undef STRUCT
diff --git a/gfs2/libgfs2/ondisk.c b/gfs2/libgfs2/ondisk.c
index 7f34bd2..b9418c5 100644
--- a/gfs2/libgfs2/ondisk.c
+++ b/gfs2/libgfs2/ondisk.c
@@ -415,7 +415,9 @@ void gfs2_dirent_in(struct gfs2_dirent *de, char *buf)
 	CPIN_16(de, str, de_rec_len);
 	CPIN_16(de, str, de_name_len);
 	CPIN_16(de, str, de_type);
+#ifdef GFS2_HAS_DE_RAHEAD
 	CPIN_16(de, str, de_rahead);
+#endif
 }
 
 void gfs2_dirent_out(struct gfs2_dirent *de, char *buf)
@@ -428,7 +430,9 @@ void gfs2_dirent_out(struct gfs2_dirent *de, char *buf)
 	CPOUT_16(de, str, de_name_len);
 	CPOUT_16(de, str, de_type);
 	memset(str->__pad, 0, sizeof(str->__pad));
+#ifdef GFS2_HAS_DE_RAHEAD
 	CPOUT_16(de, str, de_rahead);
+#endif
 }
 
 void gfs2_leaf_in(struct gfs2_leaf *lf, struct gfs2_buffer_head *bh)