gfs2: Automatically set GFS2_DIF_SYSTEM flag on system files

When new files and directories are created inside a parent directory
we automatically inherit the GFS2_DIF_SYSTEM flag (if set) and assign
it to the new file/dirs.

All new system files/dirs created in the metafs by, say gfs2_jadd,
will have this flag set because they will have parent directories in
the metafs whose GFS2_DIF_SYSTEM flag has already been set (most likely
by a previous mkfs.gfs2)
Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>

fs/gfs2/file.c

@@ -298,9 +298,9 @@ static int gfs2_set_flags(struct file *filp, u32 __user *ptr)
 		gfsflags &= ~GFS2_DIF_TOPDIR;
 		if (gfsflags & GFS2_DIF_INHERIT_JDATA)
 			gfsflags ^= (GFS2_DIF_JDATA | GFS2_DIF_INHERIT_JDATA);
-		return do_gfs2_set_flags(filp, gfsflags, ~0);
+		return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_SYSTEM);
 	}
-	return do_gfs2_set_flags(filp, gfsflags, ~GFS2_DIF_JDATA);
+	return do_gfs2_set_flags(filp, gfsflags, ~(GFS2_DIF_SYSTEM | GFS2_DIF_JDATA));
 }
 
 static long gfs2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)

fs/gfs2/inode.c

@@ -685,6 +685,11 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
 		ip->i_entries = 2;
 		break;
 	}
+
+	/* Force SYSTEM flag on all files and subdirs of a SYSTEM directory */
+	if (dip->i_diskflags & GFS2_DIF_SYSTEM)
+		ip->i_diskflags |= GFS2_DIF_SYSTEM;
+
 	gfs2_set_inode_flags(inode);
 
 	if ((GFS2_I(d_inode(sdp->sd_root_dir)) == dip) ||