Introduce MNT_UNION and MS_UNION flags. You need additional patches for util-linux for that to work. Signed-off-by: Jan Blunck --- fs/namespace.c | 6 +++++- include/linux/fs.h | 1 + include/linux/mount.h | 1 + 3 files changed, 7 insertions(+), 1 deletion(-) --- a/fs/namespace.c +++ b/fs/namespace.c @@ -437,6 +437,7 @@ static int show_vfsmnt(struct seq_file * { MNT_NODIRATIME, ",nodiratime" }, { MNT_RELATIME, ",relatime" }, { MNT_NOMNT, ",nomnt" }, + { MNT_UNION, ",union" }, { 0, NULL } }; struct proc_fs_info *fs_infop; @@ -1558,9 +1559,12 @@ long do_mount(char *dev_name, char *dir_ mnt_flags |= MNT_RELATIME; if (flags & MS_NOMNT) mnt_flags |= MNT_NOMNT; + if (flags & MS_UNION) + mnt_flags |= MNT_UNION; flags &= ~(MS_NOSUID | MS_NOEXEC | MS_NODEV | MS_ACTIVE | - MS_NOATIME | MS_NODIRATIME | MS_RELATIME | MS_NOMNT); + MS_NOATIME | MS_NODIRATIME | MS_RELATIME | MS_NOMNT | + MS_UNION ); /* ... and get the mountpoint */ retval = path_lookup(dir_name, LOOKUP_FOLLOW, &nd); --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -114,6 +114,7 @@ extern int dir_notify_enable; #define MS_REMOUNT 32 /* Alter flags of a mounted FS */ #define MS_MANDLOCK 64 /* Allow mandatory locks on an FS */ #define MS_DIRSYNC 128 /* Directory modifications are synchronous */ +#define MS_UNION 256 #define MS_NOATIME 1024 /* Do not update access times. */ #define MS_NODIRATIME 2048 /* Do not update directory access times */ #define MS_BIND 4096 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -36,6 +36,7 @@ struct mnt_namespace; #define MNT_SHARED 0x1000 /* if the vfsmount is a shared mount */ #define MNT_UNBINDABLE 0x2000 /* if the vfsmount is a unbindable mount */ #define MNT_PNODE_MASK 0x3000 /* propagation flag mask */ +#define MNT_UNION 0x4000 /* if the vfsmount is a union mount */ struct vfsmount { struct list_head mnt_hash; -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/