diff --git a/include/sys/zfs_refcount.h b/include/sys/zfs_refcount.h
index fc0cbea1cf7c..1e6449472e38 100644
--- a/include/sys/zfs_refcount.h
+++ b/include/sys/zfs_refcount.h
@@ -1,126 +1,126 @@
 /*
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
  * Common Development and Distribution License (the "License").
  * You may not use this file except in compliance with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
  * See the License for the specific language governing permissions
  * and limitations under the License.
  *
  * When distributing Covered Code, include this CDDL HEADER in each
  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  * If applicable, add the following below this CDDL HEADER, with the
  * fields enclosed by brackets "[]" replaced with your own identifying
  * information: Portions Copyright [yyyy] [name of copyright owner]
  *
  * CDDL HEADER END
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
  */
 
 #ifndef	_SYS_ZFS_REFCOUNT_H
 #define	_SYS_ZFS_REFCOUNT_H
 
 #include <sys/inttypes.h>
 #include <sys/list.h>
 #include <sys/zfs_context.h>
 
 #ifdef	__cplusplus
 extern "C" {
 #endif
 
 /*
  * If the reference is held only by the calling function and not any
  * particular object, use FTAG (which is a string) for the holder_tag.
  * Otherwise, use the object that holds the reference.
  */
 #define	FTAG ((char *)(uintptr_t)__func__)
 
 #ifdef	ZFS_DEBUG
 typedef struct reference {
 	list_node_t ref_link;
 	const void *ref_holder;
 	uint64_t ref_number;
 	uint8_t *ref_removed;
 } reference_t;
 
 typedef struct refcount {
 	kmutex_t rc_mtx;
 	boolean_t rc_tracked;
 	list_t rc_list;
 	list_t rc_removed;
 	uint64_t rc_count;
 	uint64_t rc_removed_count;
 } zfs_refcount_t;
 
 /*
  * Note: zfs_refcount_t must be initialized with
  * refcount_create[_untracked]()
  */
 
 void zfs_refcount_create(zfs_refcount_t *);
 void zfs_refcount_create_untracked(zfs_refcount_t *);
 void zfs_refcount_create_tracked(zfs_refcount_t *);
 void zfs_refcount_destroy(zfs_refcount_t *);
 void zfs_refcount_destroy_many(zfs_refcount_t *, uint64_t);
 int zfs_refcount_is_zero(zfs_refcount_t *);
 int64_t zfs_refcount_count(zfs_refcount_t *);
 int64_t zfs_refcount_add(zfs_refcount_t *, const void *);
 int64_t zfs_refcount_remove(zfs_refcount_t *, const void *);
 int64_t zfs_refcount_add_many(zfs_refcount_t *, uint64_t, const void *);
 int64_t zfs_refcount_remove_many(zfs_refcount_t *, uint64_t, const void *);
 void zfs_refcount_transfer(zfs_refcount_t *, zfs_refcount_t *);
 void zfs_refcount_transfer_ownership(zfs_refcount_t *, const void *,
     const void *);
 void zfs_refcount_transfer_ownership_many(zfs_refcount_t *, uint64_t,
     const void *, const void *);
 boolean_t zfs_refcount_held(zfs_refcount_t *, const void *);
 boolean_t zfs_refcount_not_held(zfs_refcount_t *, const void *);
 
 void zfs_refcount_init(void);
 void zfs_refcount_fini(void);
 
 #else	/* ZFS_DEBUG */
 
 typedef struct refcount {
 	uint64_t rc_count;
 } zfs_refcount_t;
 
 #define	zfs_refcount_create(rc) ((rc)->rc_count = 0)
 #define	zfs_refcount_create_untracked(rc) ((rc)->rc_count = 0)
 #define	zfs_refcount_create_tracked(rc) ((rc)->rc_count = 0)
 #define	zfs_refcount_destroy(rc) ((rc)->rc_count = 0)
 #define	zfs_refcount_destroy_many(rc, number) ((rc)->rc_count = 0)
-#define	zfs_refcount_is_zero(rc) ((rc)->rc_count == 0)
-#define	zfs_refcount_count(rc) ((rc)->rc_count)
+#define	zfs_refcount_is_zero(rc) (zfs_refcount_count(rc) == 0)
+#define	zfs_refcount_count(rc) atomic_load_64(&(rc)->rc_count)
 #define	zfs_refcount_add(rc, holder) atomic_inc_64_nv(&(rc)->rc_count)
 #define	zfs_refcount_remove(rc, holder) atomic_dec_64_nv(&(rc)->rc_count)
 #define	zfs_refcount_add_many(rc, number, holder) \
 	atomic_add_64_nv(&(rc)->rc_count, number)
 #define	zfs_refcount_remove_many(rc, number, holder) \
 	atomic_add_64_nv(&(rc)->rc_count, -number)
 #define	zfs_refcount_transfer(dst, src) { \
-	uint64_t __tmp = (src)->rc_count; \
+	uint64_t __tmp = zfs_refcount_count(src); \
 	atomic_add_64(&(src)->rc_count, -__tmp); \
 	atomic_add_64(&(dst)->rc_count, __tmp); \
 }
 #define	zfs_refcount_transfer_ownership(rc, ch, nh)		((void)0)
 #define	zfs_refcount_transfer_ownership_many(rc, nr, ch, nh)	((void)0)
-#define	zfs_refcount_held(rc, holder)			((rc)->rc_count > 0)
+#define	zfs_refcount_held(rc, holder)		(zfs_refcount_count(rc) > 0)
 #define	zfs_refcount_not_held(rc, holder)		(B_TRUE)
 
 #define	zfs_refcount_init()
 #define	zfs_refcount_fini()
 
 #endif	/* ZFS_DEBUG */
 
 #ifdef	__cplusplus
 }
 #endif
 
 #endif /* _SYS_REFCOUNT_H */
diff --git a/module/zfs/refcount.c b/module/zfs/refcount.c
index a3877b8d15f6..354e021d9d26 100644
--- a/module/zfs/refcount.c
+++ b/module/zfs/refcount.c
@@ -1,335 +1,328 @@
 /*
  * CDDL HEADER START
  *
  * The contents of this file are subject to the terms of the
  * Common Development and Distribution License (the "License").
  * You may not use this file except in compliance with the License.
  *
  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  * or http://www.opensolaris.org/os/licensing.
  * See the License for the specific language governing permissions
  * and limitations under the License.
  *
  * When distributing Covered Code, include this CDDL HEADER in each
  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  * If applicable, add the following below this CDDL HEADER, with the
  * fields enclosed by brackets "[]" replaced with your own identifying
  * information: Portions Copyright [yyyy] [name of copyright owner]
  *
  * CDDL HEADER END
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2012, 2021 by Delphix. All rights reserved.
  */
 
 #include <sys/zfs_context.h>
 #include <sys/zfs_refcount.h>
 
 /*
  * Reference count tracking is disabled by default.  It's memory requirements
  * are reasonable, however as implemented it consumes a significant amount of
  * cpu time.  Until its performance is improved it should be manually enabled.
  */
 int reference_tracking_enable = FALSE;
 int reference_history = 3; /* tunable */
 
 #ifdef	ZFS_DEBUG
 static kmem_cache_t *reference_cache;
 static kmem_cache_t *reference_history_cache;
 
 void
 zfs_refcount_init(void)
 {
 	reference_cache = kmem_cache_create("reference_cache",
 	    sizeof (reference_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
 
 	reference_history_cache = kmem_cache_create("reference_history_cache",
 	    sizeof (uint64_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
 }
 
 void
 zfs_refcount_fini(void)
 {
 	kmem_cache_destroy(reference_cache);
 	kmem_cache_destroy(reference_history_cache);
 }
 
 void
 zfs_refcount_create(zfs_refcount_t *rc)
 {
 	mutex_init(&rc->rc_mtx, NULL, MUTEX_DEFAULT, NULL);
 	list_create(&rc->rc_list, sizeof (reference_t),
 	    offsetof(reference_t, ref_link));
 	list_create(&rc->rc_removed, sizeof (reference_t),
 	    offsetof(reference_t, ref_link));
 	rc->rc_count = 0;
 	rc->rc_removed_count = 0;
 	rc->rc_tracked = reference_tracking_enable;
 }
 
 void
 zfs_refcount_create_tracked(zfs_refcount_t *rc)
 {
 	zfs_refcount_create(rc);
 	rc->rc_tracked = B_TRUE;
 }
 
 void
 zfs_refcount_create_untracked(zfs_refcount_t *rc)
 {
 	zfs_refcount_create(rc);
 	rc->rc_tracked = B_FALSE;
 }
 
 void
 zfs_refcount_destroy_many(zfs_refcount_t *rc, uint64_t number)
 {
 	reference_t *ref;
 
 	ASSERT3U(rc->rc_count, ==, number);
 	while ((ref = list_head(&rc->rc_list))) {
 		list_remove(&rc->rc_list, ref);
 		kmem_cache_free(reference_cache, ref);
 	}
 	list_destroy(&rc->rc_list);
 
 	while ((ref = list_head(&rc->rc_removed))) {
 		list_remove(&rc->rc_removed, ref);
 		kmem_cache_free(reference_history_cache, ref->ref_removed);
 		kmem_cache_free(reference_cache, ref);
 	}
 	list_destroy(&rc->rc_removed);
 	mutex_destroy(&rc->rc_mtx);
 }
 
 void
 zfs_refcount_destroy(zfs_refcount_t *rc)
 {
 	zfs_refcount_destroy_many(rc, 0);
 }
 
 int
 zfs_refcount_is_zero(zfs_refcount_t *rc)
 {
-	return (rc->rc_count == 0);
+	return (zfs_refcount_count(rc) == 0);
 }
 
 int64_t
 zfs_refcount_count(zfs_refcount_t *rc)
 {
-	return (rc->rc_count);
+	return (atomic_load_64(&rc->rc_count));
 }
 
 int64_t
 zfs_refcount_add_many(zfs_refcount_t *rc, uint64_t number, const void *holder)
 {
 	reference_t *ref = NULL;
 	int64_t count;
 
-	if (rc->rc_tracked) {
-		ref = kmem_cache_alloc(reference_cache, KM_SLEEP);
-		ref->ref_holder = holder;
-		ref->ref_number = number;
+	if (!rc->rc_tracked) {
+		count = atomic_add_64_nv(&(rc)->rc_count, number);
+		ASSERT3U(count, >=, number);
+		return (count);
 	}
+
+	ref = kmem_cache_alloc(reference_cache, KM_SLEEP);
+	ref->ref_holder = holder;
+	ref->ref_number = number;
 	mutex_enter(&rc->rc_mtx);
 	ASSERT3U(rc->rc_count, >=, 0);
-	if (rc->rc_tracked)
-		list_insert_head(&rc->rc_list, ref);
+	list_insert_head(&rc->rc_list, ref);
 	rc->rc_count += number;
 	count = rc->rc_count;
 	mutex_exit(&rc->rc_mtx);
 
 	return (count);
 }
 
 int64_t
 zfs_refcount_add(zfs_refcount_t *rc, const void *holder)
 {
 	return (zfs_refcount_add_many(rc, 1, holder));
 }
 
 int64_t
 zfs_refcount_remove_many(zfs_refcount_t *rc, uint64_t number,
     const void *holder)
 {
 	reference_t *ref;
 	int64_t count;
 
-	mutex_enter(&rc->rc_mtx);
-	ASSERT3U(rc->rc_count, >=, number);
-
 	if (!rc->rc_tracked) {
-		rc->rc_count -= number;
-		count = rc->rc_count;
-		mutex_exit(&rc->rc_mtx);
+		count = atomic_add_64_nv(&(rc)->rc_count, -number);
+		ASSERT3S(count, >=, 0);
 		return (count);
 	}
 
+	mutex_enter(&rc->rc_mtx);
+	ASSERT3U(rc->rc_count, >=, number);
 	for (ref = list_head(&rc->rc_list); ref;
 	    ref = list_next(&rc->rc_list, ref)) {
 		if (ref->ref_holder == holder && ref->ref_number == number) {
 			list_remove(&rc->rc_list, ref);
 			if (reference_history > 0) {
 				ref->ref_removed =
 				    kmem_cache_alloc(reference_history_cache,
 				    KM_SLEEP);
 				list_insert_head(&rc->rc_removed, ref);
 				rc->rc_removed_count++;
 				if (rc->rc_removed_count > reference_history) {
 					ref = list_tail(&rc->rc_removed);
 					list_remove(&rc->rc_removed, ref);
 					kmem_cache_free(reference_history_cache,
 					    ref->ref_removed);
 					kmem_cache_free(reference_cache, ref);
 					rc->rc_removed_count--;
 				}
 			} else {
 				kmem_cache_free(reference_cache, ref);
 			}
 			rc->rc_count -= number;
 			count = rc->rc_count;
 			mutex_exit(&rc->rc_mtx);
 			return (count);
 		}
 	}
 	panic("No such hold %p on refcount %llx", holder,
 	    (u_longlong_t)(uintptr_t)rc);
 	return (-1);
 }
 
 int64_t
 zfs_refcount_remove(zfs_refcount_t *rc, const void *holder)
 {
 	return (zfs_refcount_remove_many(rc, 1, holder));
 }
 
 void
 zfs_refcount_transfer(zfs_refcount_t *dst, zfs_refcount_t *src)
 {
 	int64_t count, removed_count;
 	list_t list, removed;
 
 	list_create(&list, sizeof (reference_t),
 	    offsetof(reference_t, ref_link));
 	list_create(&removed, sizeof (reference_t),
 	    offsetof(reference_t, ref_link));
 
 	mutex_enter(&src->rc_mtx);
 	count = src->rc_count;
 	removed_count = src->rc_removed_count;
 	src->rc_count = 0;
 	src->rc_removed_count = 0;
 	list_move_tail(&list, &src->rc_list);
 	list_move_tail(&removed, &src->rc_removed);
 	mutex_exit(&src->rc_mtx);
 
 	mutex_enter(&dst->rc_mtx);
 	dst->rc_count += count;
 	dst->rc_removed_count += removed_count;
 	list_move_tail(&dst->rc_list, &list);
 	list_move_tail(&dst->rc_removed, &removed);
 	mutex_exit(&dst->rc_mtx);
 
 	list_destroy(&list);
 	list_destroy(&removed);
 }
 
 void
 zfs_refcount_transfer_ownership_many(zfs_refcount_t *rc, uint64_t number,
     const void *current_holder, const void *new_holder)
 {
 	reference_t *ref;
 	boolean_t found = B_FALSE;
 
-	mutex_enter(&rc->rc_mtx);
-	if (!rc->rc_tracked) {
-		mutex_exit(&rc->rc_mtx);
+	if (!rc->rc_tracked)
 		return;
-	}
 
+	mutex_enter(&rc->rc_mtx);
 	for (ref = list_head(&rc->rc_list); ref;
 	    ref = list_next(&rc->rc_list, ref)) {
 		if (ref->ref_holder == current_holder &&
 		    ref->ref_number == number) {
 			ref->ref_holder = new_holder;
 			found = B_TRUE;
 			break;
 		}
 	}
 	ASSERT(found);
 	mutex_exit(&rc->rc_mtx);
 }
 
 void
 zfs_refcount_transfer_ownership(zfs_refcount_t *rc, const void *current_holder,
     const void *new_holder)
 {
 	return (zfs_refcount_transfer_ownership_many(rc, 1, current_holder,
 	    new_holder));
 }
 
 /*
  * If tracking is enabled, return true if a reference exists that matches
  * the "holder" tag. If tracking is disabled, then return true if a reference
  * might be held.
  */
 boolean_t
 zfs_refcount_held(zfs_refcount_t *rc, const void *holder)
 {
 	reference_t *ref;
 
-	mutex_enter(&rc->rc_mtx);
-
-	if (!rc->rc_tracked) {
-		mutex_exit(&rc->rc_mtx);
-		return (rc->rc_count > 0);
-	}
+	if (!rc->rc_tracked)
+		return (zfs_refcount_count(rc) > 0);
 
+	mutex_enter(&rc->rc_mtx);
 	for (ref = list_head(&rc->rc_list); ref;
 	    ref = list_next(&rc->rc_list, ref)) {
 		if (ref->ref_holder == holder) {
 			mutex_exit(&rc->rc_mtx);
 			return (B_TRUE);
 		}
 	}
 	mutex_exit(&rc->rc_mtx);
 	return (B_FALSE);
 }
 
 /*
  * If tracking is enabled, return true if a reference does not exist that
  * matches the "holder" tag. If tracking is disabled, always return true
  * since the reference might not be held.
  */
 boolean_t
 zfs_refcount_not_held(zfs_refcount_t *rc, const void *holder)
 {
 	reference_t *ref;
 
-	mutex_enter(&rc->rc_mtx);
-
-	if (!rc->rc_tracked) {
-		mutex_exit(&rc->rc_mtx);
+	if (!rc->rc_tracked)
 		return (B_TRUE);
-	}
 
+	mutex_enter(&rc->rc_mtx);
 	for (ref = list_head(&rc->rc_list); ref;
 	    ref = list_next(&rc->rc_list, ref)) {
 		if (ref->ref_holder == holder) {
 			mutex_exit(&rc->rc_mtx);
 			return (B_FALSE);
 		}
 	}
 	mutex_exit(&rc->rc_mtx);
 	return (B_TRUE);
 }
 
 /* BEGIN CSTYLED */
 ZFS_MODULE_PARAM(zfs, ,reference_tracking_enable, INT, ZMOD_RW,
 	"Track reference holders to refcount_t objects");
 
 ZFS_MODULE_PARAM(zfs, ,reference_history, INT, ZMOD_RW,
 	"Maximum reference holders being tracked");
 /* END CSTYLED */
 #endif	/* ZFS_DEBUG */