Prefer VERIFY0P(n) over VERIFY(n == NULL)

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <alexander.motin@TrueNAS.com>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Sponsored-by: https://despairlabs.com/sponsor/
Closes #17591

module/zfs/arc.c

@@ -3796,7 +3796,7 @@ arc_evict_hdr(arc_buf_hdr_t *hdr, uint64_t *real_evicted)
 		DTRACE_PROBE1(arc__delete, arc_buf_hdr_t *, hdr);
 
 		if (HDR_HAS_L2HDR(hdr)) {
-			ASSERT(hdr->b_l1hdr.b_pabd == NULL);
+			ASSERT0P(hdr->b_l1hdr.b_pabd);
 			ASSERT(!HDR_HAS_RABD(hdr));
 			/*
 			 * This buffer is cached on the 2nd Level ARC;

module/zfs/bpobj.c

@@ -160,8 +160,8 @@ bpobj_open(bpobj_t *bpo, objset_t *os, uint64_t object)
 	memset(bpo, 0, sizeof (*bpo));
 	mutex_init(&bpo->bpo_lock, NULL, MUTEX_DEFAULT, NULL);
 
-	ASSERT(bpo->bpo_dbuf == NULL);
-	ASSERT(bpo->bpo_phys == NULL);
+	ASSERT0P(bpo->bpo_dbuf);
+	ASSERT0P(bpo->bpo_phys);
 	ASSERT(object != 0);
 	ASSERT3U(doi.doi_type, ==, DMU_OT_BPOBJ);
 	ASSERT3U(doi.doi_bonus_type, ==, DMU_OT_BPOBJ_HDR);

module/zfs/dbuf.c

@@ -1128,8 +1128,8 @@ dbuf_verify(dmu_buf_impl_t *db)
 	DB_DNODE_ENTER(db);
 	dn = DB_DNODE(db);
 	if (dn == NULL) {
-		ASSERT(db->db_parent == NULL);
-		ASSERT(db->db_blkptr == NULL);
+		ASSERT0P(db->db_parent);
+		ASSERT0P(db->db_blkptr);
 	} else {
 		ASSERT3U(db->db.db_object, ==, dn->dn_object);
 		ASSERT3P(db->db_objset, ==, dn->dn_objset);
@@ -1180,7 +1180,7 @@ dbuf_verify(dmu_buf_impl_t *db)
 			/* db is pointed to by the dnode */
 			/* ASSERT3U(db->db_blkid, <, dn->dn_nblkptr); */
 			if (DMU_OBJECT_IS_SPECIAL(db->db.db_object))
-				ASSERT(db->db_parent == NULL);
+				ASSERT0P(db->db_parent);
 			else
 				ASSERT(db->db_parent != NULL);
 			if (db->db_blkid != DMU_SPILL_BLKID)
@@ -1384,8 +1384,8 @@ dbuf_read_done(zio_t *zio, const zbookmark_phys_t *zb, const blkptr_t *bp,
 	 * All reads are synchronous, so we must have a hold on the dbuf
 	 */
 	ASSERT(zfs_refcount_count(&db->db_holds) > 0);
-	ASSERT(db->db_buf == NULL);
-	ASSERT(db->db.db_data == NULL);
+	ASSERT0P(db->db_buf);
+	ASSERT0P(db->db.db_data);
 	if (buf == NULL) {
 		/* i/o error */
 		ASSERT(zio == NULL || zio->io_error != 0);
@@ -1584,7 +1584,7 @@ dbuf_read_impl(dmu_buf_impl_t *db, dnode_t *dn, zio_t *zio, dmu_flags_t flags,
 	ASSERT(!zfs_refcount_is_zero(&db->db_holds));
 	ASSERT(MUTEX_HELD(&db->db_mtx));
 	ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL);
-	ASSERT(db->db_buf == NULL);
+	ASSERT0P(db->db_buf);
 	ASSERT(db->db_parent == NULL ||
 	    RW_LOCK_HELD(&db->db_parent->db_rwlock));
 
@@ -1901,8 +1901,8 @@ dbuf_noread(dmu_buf_impl_t *db, dmu_flags_t flags)
 	while (db->db_state == DB_READ || db->db_state == DB_FILL)
 		cv_wait(&db->db_changed, &db->db_mtx);
 	if (db->db_state == DB_UNCACHED) {
-		ASSERT(db->db_buf == NULL);
-		ASSERT(db->db.db_data == NULL);
+		ASSERT0P(db->db_buf);
+		ASSERT0P(db->db.db_data);
 		dbuf_set_data(db, dbuf_alloc_arcbuf(db));
 		db->db_state = DB_FILL;
 		DTRACE_SET_STATE(db, "assigning filled buffer");
@@ -2017,7 +2017,7 @@ dbuf_free_range(dnode_t *dn, uint64_t start_blkid, uint64_t end_blkid,
 		if (db->db_state == DB_UNCACHED ||
 		    db->db_state == DB_NOFILL ||
 		    db->db_state == DB_EVICTING) {
-			ASSERT(db->db.db_data == NULL);
+			ASSERT0P(db->db.db_data);
 			mutex_exit(&db->db_mtx);
 			continue;
 		}
@@ -3209,7 +3209,7 @@ dbuf_assign_arcbuf(dmu_buf_impl_t *db, arc_buf_t *buf, dmu_tx_t *tx,
 		VERIFY(!dbuf_undirty(db, tx));
 		db->db_state = DB_UNCACHED;
 	}
-	ASSERT(db->db_buf == NULL);
+	ASSERT0P(db->db_buf);
 	dbuf_set_data(db, buf);
 	db->db_state = DB_FILL;
 	DTRACE_SET_STATE(db, "filling assigned arcbuf");
@@ -3269,7 +3269,7 @@ dbuf_destroy(dmu_buf_impl_t *db)
 	}
 
 	ASSERT(db->db_state == DB_UNCACHED || db->db_state == DB_NOFILL);
-	ASSERT(db->db_data_pending == NULL);
+	ASSERT0P(db->db_data_pending);
 	ASSERT(list_is_empty(&db->db_dirty_records));
 
 	db->db_state = DB_EVICTING;
@@ -3321,11 +3321,11 @@ dbuf_destroy(dmu_buf_impl_t *db)
 
 	db->db_parent = NULL;
 
-	ASSERT(db->db_buf == NULL);
-	ASSERT(db->db.db_data == NULL);
-	ASSERT(db->db_hash_next == NULL);
-	ASSERT(db->db_blkptr == NULL);
-	ASSERT(db->db_data_pending == NULL);
+	ASSERT0P(db->db_buf);
+	ASSERT0P(db->db.db_data);
+	ASSERT0P(db->db_hash_next);
+	ASSERT0P(db->db_blkptr);
+	ASSERT0P(db->db_data_pending);
 	ASSERT3U(db->db_caching_status, ==, DB_NO_CACHE);
 	ASSERT(!multilist_link_active(&db->db_cache_link));
 
@@ -4064,7 +4064,7 @@ dbuf_create_bonus(dnode_t *dn)
 {
 	ASSERT(RW_WRITE_HELD(&dn->dn_struct_rwlock));
 
-	ASSERT(dn->dn_bonus == NULL);
+	ASSERT0P(dn->dn_bonus);
 	dn->dn_bonus = dbuf_create(dn, 0, DMU_BONUS_BLKID, dn->dn_dbuf, NULL,
 	    dbuf_hash(dn->dn_objset, dn->dn_object, 0, DMU_BONUS_BLKID));
 	dn->dn_bonus->db_pending_evict = FALSE;
@@ -4416,7 +4416,7 @@ dbuf_check_blkptr(dnode_t *dn, dmu_buf_impl_t *db)
 		 * inappropriate to hook it in (i.e., nlevels mismatch).
 		 */
 		ASSERT(db->db_blkid < dn->dn_phys->dn_nblkptr);
-		ASSERT(db->db_parent == NULL);
+		ASSERT0P(db->db_parent);
 		db->db_parent = dn->dn_dbuf;
 		db->db_blkptr = &dn->dn_phys->dn_blkptr[db->db_blkid];
 		DBUF_VERIFY(db);

module/zfs/dmu_objset.c

@@ -724,7 +724,7 @@ dmu_objset_from_ds(dsl_dataset_t *ds, objset_t **osp)
 
 		if (err == 0) {
 			mutex_enter(&ds->ds_lock);
-			ASSERT(ds->ds_objset == NULL);
+			ASSERT0P(ds->ds_objset);
 			ds->ds_objset = os;
 			mutex_exit(&ds->ds_lock);
 		}

module/zfs/dnode.c

@@ -318,7 +318,7 @@ dnode_kstats_update(kstat_t *ksp, int rw)
 void
 dnode_init(void)
 {
-	ASSERT(dnode_cache == NULL);
+	ASSERT0P(dnode_cache);
 	dnode_cache = kmem_cache_create("dnode_t", sizeof (dnode_t),
 	    0, dnode_cons, dnode_dest, NULL, NULL, NULL, KMC_RECLAIMABLE);
 	kmem_cache_set_move(dnode_cache, dnode_move);

module/zfs/dsl_dataset.c

@@ -450,7 +450,7 @@ dsl_dataset_evict_sync(void *dbu)
 {
 	dsl_dataset_t *ds = dbu;
 
-	ASSERT(ds->ds_owner == NULL);
+	ASSERT0P(ds->ds_owner);
 
 	unique_remove(ds->ds_fsid_guid);
 }
@@ -460,7 +460,7 @@ dsl_dataset_evict_async(void *dbu)
 {
 	dsl_dataset_t *ds = dbu;
 
-	ASSERT(ds->ds_owner == NULL);
+	ASSERT0P(ds->ds_owner);
 
 	ds->ds_dbuf = NULL;
 

module/zfs/dsl_deadlist.c

@@ -1037,7 +1037,7 @@ dsl_livelist_iterate(void *arg, const blkptr_t *bp, boolean_t bp_freed,
 	avl_tree_t *avl = lia->avl;
 	bplist_t *to_free = lia->to_free;
 	zthr_t *t = lia->t;
-	ASSERT(tx == NULL);
+	ASSERT0P(tx);
 
 	if ((t != NULL) && (zthr_has_waiters(t) || zthr_iscancelled(t)))
 		return (SET_ERROR(EINTR));

module/zfs/dsl_destroy.c

@@ -728,7 +728,7 @@ kill_blkptr(spa_t *spa, zilog_t *zilog, const blkptr_t *bp,
 		 */
 		dsl_free(ka->tx->tx_pool, ka->tx->tx_txg, bp);
 	} else {
-		ASSERT(zilog == NULL);
+		ASSERT0P(zilog);
 		ASSERT3U(BP_GET_BIRTH(bp), >,
 		    dsl_dataset_phys(ka->ds)->ds_prev_snap_txg);
 		(void) dsl_dataset_block_kill(ka->ds, bp, tx, B_FALSE);

module/zfs/dsl_pool.c

@@ -1077,7 +1077,7 @@ upgrade_clones_cb(dsl_pool_t *dp, dsl_dataset_t *hds, void *arg)
 		dsl_dataset_phys(prev)->ds_num_children++;
 
 		if (dsl_dataset_phys(ds)->ds_next_snap_obj == 0) {
-			ASSERT(ds->ds_prev == NULL);
+			ASSERT0P(ds->ds_prev);
 			VERIFY0(dsl_dataset_hold_obj(dp,
 			    dsl_dataset_phys(ds)->ds_prev_snap_obj,
 			    ds, &ds->ds_prev));
@@ -1173,7 +1173,7 @@ dsl_pool_create_origin(dsl_pool_t *dp, dmu_tx_t *tx)
 	dsl_dataset_t *ds;
 
 	ASSERT(dmu_tx_is_syncing(tx));
-	ASSERT(dp->dp_origin_snap == NULL);
+	ASSERT0P(dp->dp_origin_snap);
 	ASSERT(rrw_held(&dp->dp_config_rwlock, RW_WRITER));
 
 	/* create the origin dir, ds, & snap-ds */

module/zfs/metaslab.c

@@ -391,7 +391,7 @@ static kstat_t *metaslab_ksp;
 void
 metaslab_stat_init(void)
 {
-	ASSERT(metaslab_alloc_trace_cache == NULL);
+	ASSERT0P(metaslab_alloc_trace_cache);
 	metaslab_alloc_trace_cache = kmem_cache_create(
 	    "metaslab_alloc_trace_cache", sizeof (metaslab_alloc_trace_t),
 	    0, NULL, NULL, NULL, NULL, NULL, 0);
@@ -465,7 +465,7 @@ metaslab_class_destroy(metaslab_class_t *mc)
 		metaslab_class_allocator_t *mca = &mc->mc_allocator[i];
 		avl_destroy(&mca->mca_tree);
 		mutex_destroy(&mca->mca_lock);
-		ASSERT(mca->mca_rotor == NULL);
+		ASSERT0P(mca->mca_rotor);
 		ASSERT0(mca->mca_reserved);
 	}
 	mutex_destroy(&mc->mc_lock);
@@ -1087,8 +1087,8 @@ metaslab_group_destroy(metaslab_group_t *mg)
 {
 	spa_t *spa = mg->mg_class->mc_spa;
 
-	ASSERT(mg->mg_prev == NULL);
-	ASSERT(mg->mg_next == NULL);
+	ASSERT0P(mg->mg_prev);
+	ASSERT0P(mg->mg_next);
 	/*
 	 * We may have gone below zero with the activation count
 	 * either because we never activated in the first place or
@@ -1118,8 +1118,8 @@ metaslab_group_activate(metaslab_group_t *mg)
 
 	ASSERT3U(spa_config_held(spa, SCL_ALLOC, RW_WRITER), !=, 0);
 
-	ASSERT(mg->mg_prev == NULL);
-	ASSERT(mg->mg_next == NULL);
+	ASSERT0P(mg->mg_prev);
+	ASSERT0P(mg->mg_next);
 	ASSERT(mg->mg_activation_count <= 0);
 
 	if (++mg->mg_activation_count <= 0)
@@ -1164,8 +1164,8 @@ metaslab_group_passivate(metaslab_group_t *mg)
 	if (--mg->mg_activation_count != 0) {
 		for (int i = 0; i < spa->spa_alloc_count; i++)
 			ASSERT(mc->mc_allocator[i].mca_rotor != mg);
-		ASSERT(mg->mg_prev == NULL);
-		ASSERT(mg->mg_next == NULL);
+		ASSERT0P(mg->mg_prev);
+		ASSERT0P(mg->mg_next);
 		ASSERT(mg->mg_activation_count < 0);
 		return;
 	}
@@ -1345,7 +1345,7 @@ metaslab_group_histogram_remove(metaslab_group_t *mg, metaslab_t *msp)
 static void
 metaslab_group_add(metaslab_group_t *mg, metaslab_t *msp)
 {
-	ASSERT(msp->ms_group == NULL);
+	ASSERT0P(msp->ms_group);
 	mutex_enter(&mg->mg_lock);
 	msp->ms_group = mg;
 	msp->ms_weight = 0;
@@ -3017,7 +3017,7 @@ metaslab_fini(metaslab_t *msp)
 	metaslab_group_remove(mg, msp);
 
 	mutex_enter(&msp->ms_lock);
-	VERIFY(msp->ms_group == NULL);
+	VERIFY0P(msp->ms_group);
 
 	/*
 	 * If this metaslab hasn't been through metaslab_sync_done() yet its

module/zfs/mmp.c

@@ -260,7 +260,7 @@ mmp_thread_stop(spa_t *spa)
 	zfs_dbgmsg("MMP thread stopped pool '%s' gethrtime %llu",
 	    spa_name(spa), gethrtime());
 
-	ASSERT(mmp->mmp_thread == NULL);
+	ASSERT0P(mmp->mmp_thread);
 	mmp->mmp_thread_exiting = 0;
 }
 

module/zfs/rrwlock.c

@@ -155,7 +155,7 @@ rrw_destroy(rrwlock_t *rrl)
 {
 	mutex_destroy(&rrl->rr_lock);
 	cv_destroy(&rrl->rr_cv);
-	ASSERT(rrl->rr_writer == NULL);
+	ASSERT0P(rrl->rr_writer);
 	zfs_refcount_destroy(&rrl->rr_anon_rcount);
 	zfs_refcount_destroy(&rrl->rr_linked_rcount);
 }
@@ -188,7 +188,7 @@ rrw_enter_read_impl(rrwlock_t *rrl, boolean_t prio, const void *tag)
 	} else {
 		(void) zfs_refcount_add(&rrl->rr_anon_rcount, tag);
 	}
-	ASSERT(rrl->rr_writer == NULL);
+	ASSERT0P(rrl->rr_writer);
 	mutex_exit(&rrl->rr_lock);
 }
 

module/zfs/spa.c

@@ -1836,9 +1836,9 @@ static void
 spa_deactivate(spa_t *spa)
 {
 	ASSERT(spa->spa_sync_on == B_FALSE);
-	ASSERT(spa->spa_dsl_pool == NULL);
-	ASSERT(spa->spa_root_vdev == NULL);
-	ASSERT(spa->spa_async_zio_root == NULL);
+	ASSERT0P(spa->spa_dsl_pool);
+	ASSERT0P(spa->spa_root_vdev);
+	ASSERT0P(spa->spa_async_zio_root);
 	ASSERT(spa->spa_state != POOL_STATE_UNINITIALIZED);
 
 	spa_evicting_os_wait(spa);
@@ -2280,7 +2280,7 @@ spa_unload(spa_t *spa)
 	 */
 	if (spa->spa_root_vdev)
 		vdev_free(spa->spa_root_vdev);
-	ASSERT(spa->spa_root_vdev == NULL);
+	ASSERT0P(spa->spa_root_vdev);
 
 	/*
 	 * Close the dsl pool.
@@ -3275,7 +3275,7 @@ static int
 livelist_track_new_cb(void *arg, const blkptr_t *bp, boolean_t bp_freed,
     dmu_tx_t *tx)
 {
-	ASSERT(tx == NULL);
+	ASSERT0P(tx);
 	livelist_new_arg_t *lna = arg;
 	if (bp_freed) {
 		bplist_append(lna->frees, bp);
@@ -4091,11 +4091,11 @@ spa_ld_parse_config(spa_t *spa, spa_import_type_t type)
 	nvlist_free(spa->spa_load_info);
 	spa->spa_load_info = fnvlist_alloc();
 
-	ASSERT(spa->spa_comment == NULL);
+	ASSERT0P(spa->spa_comment);
 	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMMENT, &comment) == 0)
 		spa->spa_comment = spa_strdup(comment);
 
-	ASSERT(spa->spa_compatibility == NULL);
+	ASSERT0P(spa->spa_compatibility);
 	if (nvlist_lookup_string(config, ZPOOL_CONFIG_COMPATIBILITY,
 	    &compatibility) == 0)
 		spa->spa_compatibility = spa_strdup(compatibility);
@@ -10541,7 +10541,7 @@ spa_sync_tq_create(spa_t *spa, const char *name)
 {
 	kthread_t **kthreads;
 
-	ASSERT(spa->spa_sync_tq == NULL);
+	ASSERT0P(spa->spa_sync_tq);
 	ASSERT3S(spa->spa_alloc_count, <=, boot_ncpus);
 
 	/*

module/zfs/spa_misc.c

@@ -471,7 +471,7 @@ spa_config_lock_destroy(spa_t *spa)
 		spa_config_lock_t *scl = &spa->spa_config_lock[i];
 		mutex_destroy(&scl->scl_lock);
 		cv_destroy(&scl->scl_cv);
-		ASSERT(scl->scl_writer == NULL);
+		ASSERT0P(scl->scl_writer);
 		ASSERT0(scl->scl_write_wanted);
 		ASSERT0(scl->scl_count);
 	}

module/zfs/space_map.c

@@ -817,7 +817,7 @@ space_map_open(space_map_t **smp, objset_t *os, uint64_t object,
 	space_map_t *sm;
 	int error;
 
-	ASSERT(*smp == NULL);
+	ASSERT0P(*smp);
 	ASSERT(os != NULL);
 	ASSERT(object != 0);
 

module/zfs/vdev.c

@@ -554,7 +554,7 @@ vdev_add_child(vdev_t *pvd, vdev_t *cvd)
 	vdev_t **newchild;
 
 	ASSERT(spa_config_held(cvd->vdev_spa, SCL_ALL, RW_WRITER) == SCL_ALL);
-	ASSERT(cvd->vdev_parent == NULL);
+	ASSERT0P(cvd->vdev_parent);
 
 	cvd->vdev_parent = pvd;
 
@@ -578,7 +578,7 @@ vdev_add_child(vdev_t *pvd, vdev_t *cvd)
 	pvd->vdev_nonrot &= cvd->vdev_nonrot;
 
 	cvd->vdev_top = (pvd->vdev_top ? pvd->vdev_top: cvd);
-	ASSERT(cvd->vdev_top->vdev_parent->vdev_parent == NULL);
+	ASSERT0P(cvd->vdev_top->vdev_parent->vdev_parent);
 
 	/*
 	 * Walk up all ancestors to update guid sum.
@@ -1133,7 +1133,7 @@ vdev_free(vdev_t *vd)
 	for (int c = 0; c < vd->vdev_children; c++)
 		vdev_free(vd->vdev_child[c]);
 
-	ASSERT(vd->vdev_child == NULL);
+	ASSERT0P(vd->vdev_child);
 	ASSERT(vd->vdev_guid_sum == vd->vdev_guid);
 
 	if (vd->vdev_ops->vdev_op_fini != NULL)
@@ -1162,7 +1162,7 @@ vdev_free(vdev_t *vd)
 	 */
 	vdev_remove_child(vd->vdev_parent, vd);
 
-	ASSERT(vd->vdev_parent == NULL);
+	ASSERT0P(vd->vdev_parent);
 	ASSERT(!list_link_active(&vd->vdev_leaf_node));
 
 	/*

module/zfs/zfs_ioctl.c

@@ -8143,7 +8143,7 @@ zfsdev_ioctl_common(uint_t vecnum, zfs_cmd_t *zc, int flag)
 		spa_t *spa;
 		nvlist_t *lognv = NULL;
 
-		ASSERT(vec->zvec_legacy_func == NULL);
+		ASSERT0P(vec->zvec_legacy_func);
 
 		/*
 		 * Add the innvl to the lognv before calling the func,

module/zfs/zil.c

@@ -1250,7 +1250,7 @@ zil_check_log_chain(dsl_pool_t *dp, dsl_dataset_t *ds, void *tx)
 	blkptr_t *bp;
 	int error;
 
-	ASSERT(tx == NULL);
+	ASSERT0P(tx);
 
 	error = dmu_objset_from_ds(ds, &os);
 	if (error != 0) {

module/zfs/zio.c

@@ -821,7 +821,7 @@ zio_wait_for_children(zio_t *zio, uint8_t childbits, enum zio_wait_type wait)
 	boolean_t waiting = B_FALSE;
 
 	mutex_enter(&zio->io_lock);
-	ASSERT(zio->io_stall == NULL);
+	ASSERT0P(zio->io_stall);
 	for (int c = 0; c < ZIO_CHILD_TYPES; c++) {
 		if (!(ZIO_CHILD_BIT_IS_SET(childbits, c)))
 			continue;
@@ -1941,7 +1941,7 @@ zio_write_compress(zio_t *zio)
 	}
 
 	ASSERT(zio->io_child_type != ZIO_CHILD_DDT);
-	ASSERT(zio->io_bp_override == NULL);
+	ASSERT0P(zio->io_bp_override);
 
 	if (!BP_IS_HOLE(bp) && BP_GET_BIRTH(bp) == zio->io_txg) {
 		/*
@@ -2436,7 +2436,7 @@ __zio_execute(zio_t *zio)
 
 		ASSERT(!MUTEX_HELD(&zio->io_lock));
 		ASSERT(ISP2(stage));
-		ASSERT(zio->io_stall == NULL);
+		ASSERT0P(zio->io_stall);
 
 		do {
 			stage <<= 1;
@@ -2590,8 +2590,8 @@ zio_reexecute(void *arg)
 
 	ASSERT(pio->io_child_type == ZIO_CHILD_LOGICAL);
 	ASSERT(pio->io_orig_stage == ZIO_STAGE_OPEN);
-	ASSERT(pio->io_gang_leader == NULL);
-	ASSERT(pio->io_gang_tree == NULL);
+	ASSERT0P(pio->io_gang_leader);
+	ASSERT0P(pio->io_gang_tree);
 
 	mutex_enter(&pio->io_lock);
 	pio->io_flags = pio->io_orig_flags;
@@ -2689,7 +2689,7 @@ zio_suspend(spa_t *spa, zio_t *zio, zio_suspend_reason_t reason)
 		ASSERT(!(zio->io_flags & ZIO_FLAG_GODFATHER));
 		ASSERT(zio != spa->spa_suspend_zio_root);
 		ASSERT(zio->io_child_type == ZIO_CHILD_LOGICAL);
-		ASSERT(zio_unique_parent(zio) == NULL);
+		ASSERT0P(zio_unique_parent(zio));
 		ASSERT(zio->io_stage == ZIO_STAGE_DONE);
 		zio_add_child(spa->spa_suspend_zio_root, zio);
 	}
@@ -2908,7 +2908,7 @@ zio_gang_node_alloc(zio_gang_node_t **gnpp, uint64_t gangblocksize)
 {
 	zio_gang_node_t *gn;
 
-	ASSERT(*gnpp == NULL);
+	ASSERT0P(*gnpp);
 
 	gn = kmem_zalloc(sizeof (*gn) +
 	    (gbh_nblkptrs(gangblocksize) * sizeof (gn)), KM_SLEEP);
@@ -2925,7 +2925,7 @@ zio_gang_node_free(zio_gang_node_t **gnpp)
 	zio_gang_node_t *gn = *gnpp;
 
 	for (int g = 0; g < gbh_nblkptrs(gn->gn_allocsize); g++)
-		ASSERT(gn->gn_child[g] == NULL);
+		ASSERT0P(gn->gn_child[g]);
 
 	zio_buf_free(gn->gn_gbh, gn->gn_allocsize);
 	kmem_free(gn, sizeof (*gn) +
@@ -3366,7 +3366,7 @@ zio_nop_write(zio_t *zio)
 	ASSERT(!(zio->io_flags & ZIO_FLAG_IO_REWRITE));
 	ASSERT(zp->zp_nopwrite);
 	ASSERT(!zp->zp_dedup);
-	ASSERT(zio->io_bp_override == NULL);
+	ASSERT0P(zio->io_bp_override);
 	ASSERT(IO_IS_ALLOCATING(zio));
 
 	/*
@@ -3495,7 +3495,7 @@ zio_ddt_read_start(zio_t *zio)
 		ddt_univ_phys_t *ddp = dde->dde_phys;
 		blkptr_t blk;
 
-		ASSERT(zio->io_vsd == NULL);
+		ASSERT0P(zio->io_vsd);
 		zio->io_vsd = dde;
 
 		if (v_self == DDT_PHYS_NONE)
@@ -3560,7 +3560,7 @@ zio_ddt_read_done(zio_t *zio)
 		zio->io_vsd = NULL;
 	}
 
-	ASSERT(zio->io_vsd == NULL);
+	ASSERT0P(zio->io_vsd);
 
 	return (zio);
 }
@@ -4415,7 +4415,7 @@ static void
 zio_dva_unallocate(zio_t *zio, zio_gang_node_t *gn, blkptr_t *bp)
 {
 	ASSERT(BP_GET_BIRTH(bp) == zio->io_txg || BP_IS_HOLE(bp));
-	ASSERT(zio->io_bp_override == NULL);
+	ASSERT0P(zio->io_bp_override);
 
 	if (!BP_IS_HOLE(bp)) {
 		metaslab_free(zio->io_spa, bp, BP_GET_BIRTH(bp), B_TRUE);
@@ -4751,7 +4751,7 @@ zio_vdev_io_done(zio_t *zio)
 	ops->vdev_op_io_done(zio);
 
 	if (unexpected_error && vd->vdev_remove_wanted == B_FALSE)
-		VERIFY(vdev_probe(vd, zio) == NULL);
+		VERIFY0P(vdev_probe(vd, zio));
 
 	return (zio);
 }