extern int block_subarray(struct mdinfo *sra);
extern int unblock_subarray(struct mdinfo *sra, const int unfreeze);
extern int block_monitor(char *container, const int freeze);
extern void unblock_monitor(char *container, const int unfreeze);
extern int fping_monitor(int sock);
extern int ping_manager(char *devname);
extern int block_subarray(struct mdinfo *sra);
extern int unblock_subarray(struct mdinfo *sra, const int unfreeze);
extern int block_monitor(char *container, const int freeze);
extern void unblock_monitor(char *container, const int unfreeze);
extern int fping_monitor(int sock);
extern int ping_manager(char *devname);