dmu_buf_impl
struct dmu_buf_impl;
struct dmu_buf_impl *dr_dbuf;
struct dmu_buf_impl *db_parent;
struct dmu_buf_impl *db_hash_next;
void dmu_tx_dirty_buf(dmu_tx_t *tx, struct dmu_buf_impl *db);
struct dmu_buf_impl;
struct dmu_buf_impl;
struct dmu_buf_impl *dn_dbuf;
struct dmu_buf_impl *dn_bonus; /* bonus buffer dbuf */