__read_seqcount_begin
nd->root_seq = __read_seqcount_begin(&nd->root.dentry->d_seq);
nd->m_seq = __read_seqcount_begin(&mount_lock.seqcount);
nd->r_seq = __read_seqcount_begin(&rename_lock.seqcount);
nd->seq = __read_seqcount_begin(&nd->path.dentry->d_seq);
#define raw_read_seqcount_begin(s) __read_seqcount_begin(s)