spa_log_sm_nblocks
uint64_t log_blocks_before = spa_log_sm_nblocks(spa);
uint64_t log_blocks_after = spa_log_sm_nblocks(spa);
(u_longlong_t)spa_log_sm_nblocks(spa),
VERIFY3U(blk_in_logs, ==, spa_log_sm_nblocks(spa));
spa_log_sm_blocklimit(spa) - spa_log_sm_nblocks(spa) - incoming;
uint64_t spa_log_sm_nblocks(spa_t *);