static void dmu_objset_sync_dnodes(list_t *list, list_t *newlist, dmu_tx_t *tx) { dnode_t *dn; while (dn = list_head(list)) { ASSERT(dn->dn_object != DMU_META_DNODE_OBJECT); ASSERT(dn->dn_dbuf->db_data_pending); /* * Initialize dn_zio outside dnode_sync() because the * meta-dnode needs to set it ouside dnode_sync(). */ dn->dn_zio = dn->dn_dbuf->db_data_pending->dr_zio; ASSERT(dn->dn_zio); ASSERT3U(dn->dn_nlevels, <=, DN_MAX_LEVELS); list_remove(list, dn); if (newlist) { (void) dnode_add_ref(dn, newlist); list_insert_tail(newlist, dn); } dnode_sync(dn, tx); } }
/* * returns ENOENT, EIO, or 0. */ int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp) { dnode_t *dn; dmu_buf_impl_t *db; int error; error = dnode_hold(os->os, object, FTAG, &dn); if (error) return (error); rw_enter(&dn->dn_struct_rwlock, RW_READER); if (dn->dn_bonus == NULL) { rw_exit(&dn->dn_struct_rwlock); rw_enter(&dn->dn_struct_rwlock, RW_WRITER); if (dn->dn_bonus == NULL) dbuf_create_bonus(dn); } db = dn->dn_bonus; rw_exit(&dn->dn_struct_rwlock); /* as long as the bonus buf is held, the dnode will be held */ if (refcount_add(&db->db_holds, tag) == 1) VERIFY(dnode_add_ref(dn, db)); dnode_rele(dn, FTAG); VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED)); *dbp = &db->db; return (0); }
int dmu_objset_evict_dbufs(objset_t *os) { dnode_t *dn; mutex_enter(&os->os_lock); /* process the mdn last, since the other dnodes have holds on it */ list_remove(&os->os_dnodes, DMU_META_DNODE(os)); list_insert_tail(&os->os_dnodes, DMU_META_DNODE(os)); /* * Find the first dnode with holds. We have to do this dance * because dnode_add_ref() only works if you already have a * hold. If there are no holds then it has no dbufs so OK to * skip. */ for (dn = list_head(&os->os_dnodes); dn && !dnode_add_ref(dn, FTAG); dn = list_next(&os->os_dnodes, dn)) continue; while (dn) { dnode_t *next_dn = dn; do { next_dn = list_next(&os->os_dnodes, next_dn); } while (next_dn && !dnode_add_ref(next_dn, FTAG)); mutex_exit(&os->os_lock); dnode_evict_dbufs(dn); dnode_rele(dn, FTAG); mutex_enter(&os->os_lock); dn = next_dn; } dn = list_head(&os->os_dnodes); mutex_exit(&os->os_lock); return (dn != DMU_META_DNODE(os)); }
/* * returns ENOENT, EIO, or 0. */ int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **dbp) { dnode_t *dn; dmu_buf_impl_t *db; int error; error = dnode_hold(os, object, FTAG, &dn); if (error) return (error); rw_enter(&dn->dn_struct_rwlock, RW_READER); if (dn->dn_bonus == NULL) { rw_exit(&dn->dn_struct_rwlock); rw_enter(&dn->dn_struct_rwlock, RW_WRITER); if (dn->dn_bonus == NULL) dbuf_create_bonus(dn); } db = dn->dn_bonus; /* as long as the bonus buf is held, the dnode will be held */ if (refcount_add(&db->db_holds, tag) == 1) { VERIFY(dnode_add_ref(dn, db)); atomic_inc_32(&dn->dn_dbufs_count); } /* * Wait to drop dn_struct_rwlock until after adding the bonus dbuf's * hold and incrementing the dbuf count to ensure that dnode_move() sees * a dnode hold for every dbuf. */ rw_exit(&dn->dn_struct_rwlock); dnode_rele(dn, FTAG); VERIFY(0 == dbuf_read(db, NULL, DB_RF_MUST_SUCCEED | DB_RF_NOPREFETCH)); *dbp = &db->db; return (0); }
void dmu_objset_evict_dbufs(objset_t *os) { dnode_t dn_marker; dnode_t *dn; mutex_enter(&os->os_lock); dn = list_head(&os->os_dnodes); while (dn != NULL) { /* * Skip dnodes without holds. We have to do this dance * because dnode_add_ref() only works if there is already a * hold. If the dnode has no holds, then it has no dbufs. */ if (dnode_add_ref(dn, FTAG)) { list_insert_after(&os->os_dnodes, dn, &dn_marker); mutex_exit(&os->os_lock); dnode_evict_dbufs(dn); dnode_rele(dn, FTAG); mutex_enter(&os->os_lock); dn = list_next(&os->os_dnodes, &dn_marker); list_remove(&os->os_dnodes, &dn_marker); } else { dn = list_next(&os->os_dnodes, dn); } } mutex_exit(&os->os_lock); if (DMU_USERUSED_DNODE(os) != NULL) { dnode_evict_dbufs(DMU_GROUPUSED_DNODE(os)); dnode_evict_dbufs(DMU_USERUSED_DNODE(os)); } dnode_evict_dbufs(DMU_META_DNODE(os)); }