extern int zvol_check_volsize(uint64_t volsize, uint64_t blocksize);
extern int zvol_check_volblocksize(uint64_t volblocksize);
extern int zvol_get_stats(objset_t *os, nvlist_t *nv);
extern int zvol_check_volsize(uint64_t volsize, uint64_t blocksize);
extern int zvol_check_volblocksize(uint64_t volblocksize);
extern int zvol_get_stats(objset_t *os, nvlist_t *nv);