[GFS2] Add gfs2_internal_read()

Add the new external read function. Its temporarily in jdata.c
even though the protoype is in ops_file.h - this will change
shortly. The current implementation will change to a page cache
one when that happens.

In order to effect the above changes, the various internal inodes
now have Linux inodes attached to them. We keep the references to
the Linux inodes, rather than the gfs2_inodes in the super block.

In order to get everything to work correctly I've had to reorder
the init sequence on mount (which I should probably have done
earlier when .gfs2_admin was made visible).

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h
index 4df7da5..e42ae38 100644
--- a/fs/gfs2/inode.h
+++ b/fs/gfs2/inode.h
@@ -60,14 +60,23 @@
 
 int gfs2_repermission(struct inode *inode, int mask, struct nameidata *nd);
 
-static inline int gfs2_lookup_simple(struct gfs2_inode *dip, char *name,
-				     struct gfs2_inode **ipp)
+static inline int gfs2_lookup_simple(struct inode *dip, char *name,
+				     struct inode **ipp)
 {
+	struct gfs2_inode *ip;
 	struct qstr qstr;
+	int err;
 	memset(&qstr, 0, sizeof(struct qstr));
 	qstr.name = name;
 	qstr.len = strlen(name);
-	return gfs2_lookupi(dip, &qstr, 1, ipp);
+	err = gfs2_lookupi(get_v2ip(dip), &qstr, 1, &ip);
+	if (err == 0) {
+		*ipp = gfs2_ip2v(ip);
+		if (*ipp == NULL)
+			err = -ENOMEM;
+		gfs2_inode_put(ip);
+	}
+	return err;
 }
 
 #endif /* __INODE_DOT_H__ */