mount: save group and master in image file (v2)

They are required for restoring shared and slave mounts

v2: use the same names of variables in image and in code
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

mount.c

@@ -523,6 +523,10 @@ static int dump_one_mountpoint(struct mount_info *pm, int fd)
 	me.mountpoint		= pm->mountpoint;
 	me.source		= pm->source;
 	me.options		= pm->options;
+	me.shared_id		= pm->shared_id;
+	me.has_shared_id	= true;
+	me.master_id		= pm->master_id;
+	me.has_master_id	= true;
 
 	if (!me.fstype && !is_root_mount(pm)) {
 		pr_err("FS mnt %s dev %#x root %s unsupported\n",
@@ -810,6 +814,8 @@ static int populate_mnt_ns(int ns_pid)
 		pm->parent_mnt_id	= me->parent_mnt_id;
 		pm->s_dev		= me->root_dev;
 		pm->flags		= me->flags;
+		pm->shared_id		= me->shared_id;
+		pm->master_id		= me->master_id;
 
 		/* FIXME: abort unsupported early */
 		pm->fstype		= decode_fstype(me->fstype);

protobuf/mnt.proto

@@ -20,4 +20,7 @@ message mnt_entry {
 	required string		mountpoint		= 7;
 	required string		source			= 8;
 	required string		options			= 9;
+
+	optional uint32		shared_id		= 10;
+	optional uint32		master_id		= 11;
 }