diff --git a/include/libzfs_impl.h b/include/libzfs_impl.h
index 78b5a05865..35b92f6d95 100644
--- a/include/libzfs_impl.h
+++ b/include/libzfs_impl.h
@@ -148,6 +148,7 @@ int no_memory(libzfs_handle_t *);
 
 int zfs_standard_error(libzfs_handle_t *, int, const char *);
 int zfs_standard_error_fmt(libzfs_handle_t *, int, const char *, ...);
+void zfs_setprop_error(libzfs_handle_t *, zfs_prop_t, int, char *);
 int zpool_standard_error(libzfs_handle_t *, int, const char *);
 int zpool_standard_error_fmt(libzfs_handle_t *, int, const char *, ...);
 
diff --git a/include/libzutil.h b/include/libzutil.h
index 98998e1950..82a8026789 100644
--- a/include/libzutil.h
+++ b/include/libzutil.h
@@ -136,6 +136,7 @@ extern void zfs_nicenum(uint64_t, char *, size_t);
 extern void zfs_nicenum_format(uint64_t, char *, size_t,
     enum zfs_nicenum_format);
 extern void zfs_nicetime(uint64_t, char *, size_t);
+extern void zfs_niceraw(uint64_t, char *, size_t);
 
 #define	nicenum(num, buf, size)	zfs_nicenum(num, buf, size)
 
diff --git a/include/os/freebsd/zfs/sys/vdev_os.h b/include/os/freebsd/zfs/sys/vdev_os.h
index e2780fdbb6..59da954b90 100644
--- a/include/os/freebsd/zfs/sys/vdev_os.h
+++ b/include/os/freebsd/zfs/sys/vdev_os.h
@@ -27,4 +27,7 @@
 #define	_SYS_VDEV_OS_H
 
 extern int vdev_label_write_pad2(vdev_t *vd, const char *buf, size_t size);
+extern int vdev_geom_read_pool_label(const char *name, nvlist_t ***configs,
+    uint64_t *count);
+
 #endif
diff --git a/include/os/freebsd/zfs/sys/zfs_vfsops.h b/include/os/freebsd/zfs/sys/zfs_vfsops.h
index 26652004b2..70ada204a2 100644
--- a/include/os/freebsd/zfs/sys/zfs_vfsops.h
+++ b/include/os/freebsd/zfs/sys/zfs_vfsops.h
@@ -153,6 +153,9 @@ typedef struct zfid_long {
 extern uint_t zfs_fsyncer_key;
 extern int zfs_super_owner;
 
+extern void zfs_init(void);
+extern void zfs_fini(void);
+
 extern int zfs_suspend_fs(zfsvfs_t *zfsvfs);
 extern int zfs_resume_fs(zfsvfs_t *zfsvfs, struct dsl_dataset *ds);
 extern int zfs_end_fs(zfsvfs_t *zfsvfs, struct dsl_dataset *ds);
diff --git a/include/os/linux/spl/sys/trace.h b/include/os/linux/spl/sys/trace.h
index 55c5873582..b148ace6ab 100644
--- a/include/os/linux/spl/sys/trace.h
+++ b/include/os/linux/spl/sys/trace.h
@@ -104,27 +104,45 @@
 	trace_zfs_##name((uintptr_t)(arg1), (uintptr_t)(arg2), \
 	(uintptr_t)(arg3), (uintptr_t)(arg4))
 
+#define	PROTO_DTRACE_PROBE(name)				\
+	noinline void trace_zfs_##name(void)
+#define	PROTO_DTRACE_PROBE1(name)				\
+	noinline void trace_zfs_##name(uintptr_t)
+#define	PROTO_DTRACE_PROBE2(name)				\
+	noinline void trace_zfs_##name(uintptr_t, uintptr_t)
+#define	PROTO_DTRACE_PROBE3(name)				\
+	noinline void trace_zfs_##name(uintptr_t, uintptr_t,	\
+	uintptr_t)
+#define	PROTO_DTRACE_PROBE4(name)				\
+	noinline void trace_zfs_##name(uintptr_t, uintptr_t,	\
+	uintptr_t, uintptr_t)
+
 #if defined(CREATE_TRACE_POINTS)
 
 #define	FUNC_DTRACE_PROBE(name)					\
+PROTO_DTRACE_PROBE(name);					\
 noinline void trace_zfs_##name(void) { }			\
 EXPORT_SYMBOL(trace_zfs_##name)
 
 #define	FUNC_DTRACE_PROBE1(name)				\
+PROTO_DTRACE_PROBE1(name);					\
 noinline void trace_zfs_##name(uintptr_t arg1) { }		\
 EXPORT_SYMBOL(trace_zfs_##name)
 
 #define	FUNC_DTRACE_PROBE2(name)				\
+PROTO_DTRACE_PROBE2(name);					\
 noinline void trace_zfs_##name(uintptr_t arg1,			\
     uintptr_t arg2) { }						\
 EXPORT_SYMBOL(trace_zfs_##name)
 
 #define	FUNC_DTRACE_PROBE3(name)				\
+PROTO_DTRACE_PROBE3(name);					\
 noinline void trace_zfs_##name(uintptr_t arg1,			\
     uintptr_t arg2, uintptr_t arg3) { }				\
 EXPORT_SYMBOL(trace_zfs_##name)
 
 #define	FUNC_DTRACE_PROBE4(name)				\
+PROTO_DTRACE_PROBE4(name);					\
 noinline void trace_zfs_##name(uintptr_t arg1,			\
     uintptr_t arg2, uintptr_t arg3, uintptr_t arg4) { }		\
 EXPORT_SYMBOL(trace_zfs_##name)
@@ -146,19 +164,6 @@ EXPORT_SYMBOL(trace_zfs_##name)
 
 #else /* CREATE_TRACE_POINTS */
 
-#define	PROTO_DTRACE_PROBE(name)				\
-	noinline void trace_zfs_##name(void)
-#define	PROTO_DTRACE_PROBE1(name)				\
-	noinline void trace_zfs_##name(uintptr_t)
-#define	PROTO_DTRACE_PROBE2(name)				\
-	noinline void trace_zfs_##name(uintptr_t, uintptr_t)
-#define	PROTO_DTRACE_PROBE3(name)				\
-	noinline void trace_zfs_##name(uintptr_t, uintptr_t,	\
-	uintptr_t)
-#define	PROTO_DTRACE_PROBE4(name)				\
-	noinline void trace_zfs_##name(uintptr_t, uintptr_t,	\
-	uintptr_t, uintptr_t)
-
 #define	DEFINE_DTRACE_PROBE(name)	PROTO_DTRACE_PROBE(name)
 #define	DEFINE_DTRACE_PROBE1(name)	PROTO_DTRACE_PROBE1(name)
 #define	DEFINE_DTRACE_PROBE2(name)	PROTO_DTRACE_PROBE2(name)
diff --git a/include/os/linux/zfs/sys/zfs_vfsops.h b/include/os/linux/zfs/sys/zfs_vfsops.h
index 4e60a081ac..24a0a2e6a0 100644
--- a/include/os/linux/zfs/sys/zfs_vfsops.h
+++ b/include/os/linux/zfs/sys/zfs_vfsops.h
@@ -195,6 +195,9 @@ typedef struct zfid_long {
 #define	SHORT_FID_LEN	(sizeof (zfid_short_t) - sizeof (uint16_t))
 #define	LONG_FID_LEN	(sizeof (zfid_long_t) - sizeof (uint16_t))
 
+extern void zfs_init(void);
+extern void zfs_fini(void);
+
 extern int zfs_suspend_fs(zfsvfs_t *zfsvfs);
 extern int zfs_resume_fs(zfsvfs_t *zfsvfs, struct dsl_dataset *ds);
 extern int zfs_end_fs(zfsvfs_t *zfsvfs, struct dsl_dataset *ds);
diff --git a/include/sys/lua/luaconf.h b/include/sys/lua/luaconf.h
index fa7861336f..ce99f339fe 100644
--- a/include/sys/lua/luaconf.h
+++ b/include/sys/lua/luaconf.h
@@ -15,6 +15,7 @@
 extern ssize_t lcompat_sprintf(char *, size_t size, const char *, ...);
 extern int64_t lcompat_strtoll(const char *, char **);
 extern int64_t lcompat_pow(int64_t, int64_t);
+extern int lcompat_hashnum(int64_t);
 
 /*
 ** ==================================================================
diff --git a/include/sys/vdev_raidz_impl.h b/include/sys/vdev_raidz_impl.h
index 81a321ee5b..8492daedb6 100644
--- a/include/sys/vdev_raidz_impl.h
+++ b/include/sys/vdev_raidz_impl.h
@@ -133,6 +133,8 @@ typedef struct raidz_map {
 #define	RAIDZ_ORIGINAL_IMPL	(INT_MAX)
 
 extern const raidz_impl_ops_t vdev_raidz_scalar_impl;
+extern boolean_t raidz_will_scalar_work(void);
+
 #if defined(__x86_64) && defined(HAVE_SSE2)	/* only x86_64 for now */
 extern const raidz_impl_ops_t vdev_raidz_sse2_impl;
 #endif
diff --git a/include/sys/zil.h b/include/sys/zil.h
index 716b19e564..7e61a13301 100644
--- a/include/sys/zil.h
+++ b/include/sys/zil.h
@@ -496,6 +496,7 @@ extern void	zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx);
 extern void	zil_async_to_sync(zilog_t *zilog, uint64_t oid);
 extern void	zil_commit(zilog_t *zilog, uint64_t oid);
 extern void	zil_commit_impl(zilog_t *zilog, uint64_t oid);
+extern void	zil_remove_async(zilog_t *zilog, uint64_t oid);
 
 extern int	zil_reset(const char *osname, void *txarg);
 extern int	zil_claim(struct dsl_pool *dp,
diff --git a/lib/libspl/include/umem.h b/lib/libspl/include/umem.h
index a92dce9b25..49e9f9c146 100644
--- a/lib/libspl/include/umem.h
+++ b/lib/libspl/include/umem.h
@@ -80,6 +80,11 @@ typedef struct umem_cache {
 	int			cache_cflags;
 } umem_cache_t;
 
+/* Prototypes for functions to provide defaults for umem envvars */
+const char *_umem_debug_init(void);
+const char *_umem_options_init(void);
+const char *_umem_logging_init(void);
+
 static inline void *
 umem_alloc(size_t size, int flags)
 {
diff --git a/lib/libzfs/libzfs_dataset.c b/lib/libzfs/libzfs_dataset.c
index 4f1dec1380..4252c8cf04 100644
--- a/lib/libzfs/libzfs_dataset.c
+++ b/lib/libzfs/libzfs_dataset.c
@@ -1722,114 +1722,6 @@ zfs_fix_auto_resv(zfs_handle_t *zhp, nvlist_t *nvl)
 	return (1);
 }
 
-void
-zfs_setprop_error(libzfs_handle_t *hdl, zfs_prop_t prop, int err,
-    char *errbuf)
-{
-	switch (err) {
-
-	case ENOSPC:
-		/*
-		 * For quotas and reservations, ENOSPC indicates
-		 * something different; setting a quota or reservation
-		 * doesn't use any disk space.
-		 */
-		switch (prop) {
-		case ZFS_PROP_QUOTA:
-		case ZFS_PROP_REFQUOTA:
-			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
-			    "size is less than current used or "
-			    "reserved space"));
-			(void) zfs_error(hdl, EZFS_PROPSPACE, errbuf);
-			break;
-
-		case ZFS_PROP_RESERVATION:
-		case ZFS_PROP_REFRESERVATION:
-			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
-			    "size is greater than available space"));
-			(void) zfs_error(hdl, EZFS_PROPSPACE, errbuf);
-			break;
-
-		default:
-			(void) zfs_standard_error(hdl, err, errbuf);
-			break;
-		}
-		break;
-
-	case EBUSY:
-		(void) zfs_standard_error(hdl, EBUSY, errbuf);
-		break;
-
-	case EROFS:
-		(void) zfs_error(hdl, EZFS_DSREADONLY, errbuf);
-		break;
-
-	case E2BIG:
-		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
-		    "property value too long"));
-		(void) zfs_error(hdl, EZFS_BADPROP, errbuf);
-		break;
-
-	case ENOTSUP:
-		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
-		    "pool and or dataset must be upgraded to set this "
-		    "property or value"));
-		(void) zfs_error(hdl, EZFS_BADVERSION, errbuf);
-		break;
-
-	case ERANGE:
-		if (prop == ZFS_PROP_COMPRESSION ||
-		    prop == ZFS_PROP_DNODESIZE ||
-		    prop == ZFS_PROP_RECORDSIZE) {
-			(void) zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
-			    "property setting is not allowed on "
-			    "bootable datasets"));
-			(void) zfs_error(hdl, EZFS_NOTSUP, errbuf);
-		} else if (prop == ZFS_PROP_CHECKSUM ||
-		    prop == ZFS_PROP_DEDUP) {
-			(void) zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
-			    "property setting is not allowed on "
-			    "root pools"));
-			(void) zfs_error(hdl, EZFS_NOTSUP, errbuf);
-		} else {
-			(void) zfs_standard_error(hdl, err, errbuf);
-		}
-		break;
-
-	case EINVAL:
-		if (prop == ZPROP_INVAL) {
-			(void) zfs_error(hdl, EZFS_BADPROP, errbuf);
-		} else {
-			(void) zfs_standard_error(hdl, err, errbuf);
-		}
-		break;
-
-	case EACCES:
-		if (prop == ZFS_PROP_KEYLOCATION) {
-			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
-			    "keylocation may only be set on encryption roots"));
-			(void) zfs_error(hdl, EZFS_BADPROP, errbuf);
-		} else {
-			(void) zfs_standard_error(hdl, err, errbuf);
-		}
-		break;
-
-	case EOVERFLOW:
-		/*
-		 * This platform can't address a volume this big.
-		 */
-#ifdef _ILP32
-		if (prop == ZFS_PROP_VOLSIZE) {
-			(void) zfs_error(hdl, EZFS_VOLTOOBIG, errbuf);
-			break;
-		}
-#endif
-		/* FALLTHROUGH */
-	default:
-		(void) zfs_standard_error(hdl, err, errbuf);
-	}
-}
-
 static boolean_t
 zfs_is_namespace_prop(zfs_prop_t prop)
 {
diff --git a/lib/libzfs/libzfs_sendrecv.c b/lib/libzfs/libzfs_sendrecv.c
index 097766c191..75f4e056b6 100644
--- a/lib/libzfs/libzfs_sendrecv.c
+++ b/lib/libzfs/libzfs_sendrecv.c
@@ -69,9 +69,6 @@
 #include <sys/socket.h>
 #include <sys/sha2.h>
 
-/* in libzfs_dataset.c */
-extern void zfs_setprop_error(libzfs_handle_t *, zfs_prop_t, int, char *);
-
 static int zfs_receive_impl(libzfs_handle_t *, const char *, const char *,
     recvflags_t *, int, const char *, nvlist_t *, avl_tree_t *, char **,
     const char *, nvlist_t *);
diff --git a/lib/libzfs/libzfs_util.c b/lib/libzfs/libzfs_util.c
index e8ef40e5ab..04936250b6 100644
--- a/lib/libzfs/libzfs_util.c
+++ b/lib/libzfs/libzfs_util.c
@@ -481,6 +481,114 @@ zfs_standard_error_fmt(libzfs_handle_t *hdl, int error, const char *fmt, ...)
 	return (-1);
 }
 
+void
+zfs_setprop_error(libzfs_handle_t *hdl, zfs_prop_t prop, int err,
+    char *errbuf)
+{
+	switch (err) {
+
+	case ENOSPC:
+		/*
+		 * For quotas and reservations, ENOSPC indicates
+		 * something different; setting a quota or reservation
+		 * doesn't use any disk space.
+		 */
+		switch (prop) {
+		case ZFS_PROP_QUOTA:
+		case ZFS_PROP_REFQUOTA:
+			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+			    "size is less than current used or "
+			    "reserved space"));
+			(void) zfs_error(hdl, EZFS_PROPSPACE, errbuf);
+			break;
+
+		case ZFS_PROP_RESERVATION:
+		case ZFS_PROP_REFRESERVATION:
+			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+			    "size is greater than available space"));
+			(void) zfs_error(hdl, EZFS_PROPSPACE, errbuf);
+			break;
+
+		default:
+			(void) zfs_standard_error(hdl, err, errbuf);
+			break;
+		}
+		break;
+
+	case EBUSY:
+		(void) zfs_standard_error(hdl, EBUSY, errbuf);
+		break;
+
+	case EROFS:
+		(void) zfs_error(hdl, EZFS_DSREADONLY, errbuf);
+		break;
+
+	case E2BIG:
+		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+		    "property value too long"));
+		(void) zfs_error(hdl, EZFS_BADPROP, errbuf);
+		break;
+
+	case ENOTSUP:
+		zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+		    "pool and or dataset must be upgraded to set this "
+		    "property or value"));
+		(void) zfs_error(hdl, EZFS_BADVERSION, errbuf);
+		break;
+
+	case ERANGE:
+		if (prop == ZFS_PROP_COMPRESSION ||
+		    prop == ZFS_PROP_DNODESIZE ||
+		    prop == ZFS_PROP_RECORDSIZE) {
+			(void) zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+			    "property setting is not allowed on "
+			    "bootable datasets"));
+			(void) zfs_error(hdl, EZFS_NOTSUP, errbuf);
+		} else if (prop == ZFS_PROP_CHECKSUM ||
+		    prop == ZFS_PROP_DEDUP) {
+			(void) zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+			    "property setting is not allowed on "
+			    "root pools"));
+			(void) zfs_error(hdl, EZFS_NOTSUP, errbuf);
+		} else {
+			(void) zfs_standard_error(hdl, err, errbuf);
+		}
+		break;
+
+	case EINVAL:
+		if (prop == ZPROP_INVAL) {
+			(void) zfs_error(hdl, EZFS_BADPROP, errbuf);
+		} else {
+			(void) zfs_standard_error(hdl, err, errbuf);
+		}
+		break;
+
+	case EACCES:
+		if (prop == ZFS_PROP_KEYLOCATION) {
+			zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
+			    "keylocation may only be set on encryption roots"));
+			(void) zfs_error(hdl, EZFS_BADPROP, errbuf);
+		} else {
+			(void) zfs_standard_error(hdl, err, errbuf);
+		}
+		break;
+
+	case EOVERFLOW:
+		/*
+		 * This platform can't address a volume this big.
+		 */
+#ifdef _ILP32
+		if (prop == ZFS_PROP_VOLSIZE) {
+			(void) zfs_error(hdl, EZFS_VOLTOOBIG, errbuf);
+			break;
+		}
+#endif
+		/* FALLTHROUGH */
+	default:
+		(void) zfs_standard_error(hdl, err, errbuf);
+	}
+}
+
 int
 zpool_standard_error(libzfs_handle_t *hdl, int error, const char *msg)
 {
diff --git a/module/icp/algs/aes/aes_impl_x86-64.c b/module/icp/algs/aes/aes_impl_x86-64.c
index 0ee7ee99c3..19f8fd5012 100644
--- a/module/icp/algs/aes/aes_impl_x86-64.c
+++ b/module/icp/algs/aes/aes_impl_x86-64.c
@@ -25,18 +25,6 @@
 #if defined(__x86_64)
 
 #include <sys/simd.h>
-
-/* These functions are used to execute amd64 instructions for AMD or Intel: */
-extern int rijndael_key_setup_enc_amd64(uint32_t rk[],
-	const uint32_t cipherKey[], int keyBits);
-extern int rijndael_key_setup_dec_amd64(uint32_t rk[],
-	const uint32_t cipherKey[], int keyBits);
-extern void aes_encrypt_amd64(const uint32_t rk[], int Nr,
-	const uint32_t pt[4], uint32_t ct[4]);
-extern void aes_decrypt_amd64(const uint32_t rk[], int Nr,
-	const uint32_t ct[4], uint32_t pt[4]);
-
-
 #include <aes/aes_impl.h>
 
 /*
diff --git a/module/icp/algs/skein/skein.c b/module/icp/algs/skein/skein.c
index 0187f7be6c..39a0bff35d 100644
--- a/module/icp/algs/skein/skein.c
+++ b/module/icp/algs/skein/skein.c
@@ -12,14 +12,6 @@
 #include <sys/skein.h>		/* get the Skein API definitions   */
 #include "skein_impl.h"		/* get internal definitions */
 
-/* External function to process blkCnt (nonzero) full block(s) of data. */
-void Skein_256_Process_Block(Skein_256_Ctxt_t *ctx, const uint8_t *blkPtr,
-    size_t blkCnt, size_t byteCntAdd);
-void Skein_512_Process_Block(Skein_512_Ctxt_t *ctx, const uint8_t *blkPtr,
-    size_t blkCnt, size_t byteCntAdd);
-void Skein1024_Process_Block(Skein1024_Ctxt_t *ctx, const uint8_t *blkPtr,
-    size_t blkCnt, size_t byteCntAdd);
-
 /* 256-bit Skein */
 /* init the context for a straight hashing operation  */
 int
diff --git a/module/icp/algs/skein/skein_impl.h b/module/icp/algs/skein/skein_impl.h
index ea834e6199..205a517d69 100644
--- a/module/icp/algs/skein/skein_impl.h
+++ b/module/icp/algs/skein/skein_impl.h
@@ -281,4 +281,12 @@ extern const uint64_t SKEIN1024_IV_384[];
 extern const uint64_t SKEIN1024_IV_512[];
 extern const uint64_t SKEIN1024_IV_1024[];
 
+/* Functions to process blkCnt (nonzero) full block(s) of data. */
+void Skein_256_Process_Block(Skein_256_Ctxt_t *ctx, const uint8_t *blkPtr,
+    size_t blkCnt, size_t byteCntAdd);
+void Skein_512_Process_Block(Skein_512_Ctxt_t *ctx, const uint8_t *blkPtr,
+    size_t blkCnt, size_t byteCntAdd);
+void Skein1024_Process_Block(Skein1024_Ctxt_t *ctx, const uint8_t *blkPtr,
+    size_t blkCnt, size_t byteCntAdd);
+
 #endif	/* _SKEIN_IMPL_H_ */
diff --git a/module/icp/include/aes/aes_impl.h b/module/icp/include/aes/aes_impl.h
index 0484462ca4..41dccaa384 100644
--- a/module/icp/include/aes/aes_impl.h
+++ b/module/icp/include/aes/aes_impl.h
@@ -195,6 +195,16 @@ struct aes_impl_ops {
 extern const aes_impl_ops_t aes_generic_impl;
 #if defined(__x86_64)
 extern const aes_impl_ops_t aes_x86_64_impl;
+
+/* These functions are used to execute amd64 instructions for AMD or Intel: */
+extern int rijndael_key_setup_enc_amd64(uint32_t rk[],
+	const uint32_t cipherKey[], int keyBits);
+extern int rijndael_key_setup_dec_amd64(uint32_t rk[],
+	const uint32_t cipherKey[], int keyBits);
+extern void aes_encrypt_amd64(const uint32_t rk[], int Nr,
+	const uint32_t pt[4], uint32_t ct[4]);
+extern void aes_decrypt_amd64(const uint32_t rk[], int Nr,
+	const uint32_t ct[4], uint32_t pt[4]);
 #endif
 #if defined(__x86_64) && defined(HAVE_AES)
 extern const aes_impl_ops_t aes_aesni_impl;
diff --git a/module/lua/llimits.h b/module/lua/llimits.h
index 2126a14648..b989160f41 100644
--- a/module/lua/llimits.h
+++ b/module/lua/llimits.h
@@ -281,8 +281,6 @@ union luai_Cast { double l_d; LUA_INT32 l_p[2]; };
 
 #if defined(ltable_c) && !defined(luai_hashnum)
 
-extern int lcompat_hashnum(int64_t);
-
 #define luai_hashnum(i,n) (i = lcompat_hashnum(n))
 
 #endif
diff --git a/module/os/freebsd/spl/acl_common.c b/module/os/freebsd/spl/acl_common.c
index ee89c8233e..66e27cefa3 100644
--- a/module/os/freebsd/spl/acl_common.c
+++ b/module/os/freebsd/spl/acl_common.c
@@ -159,7 +159,7 @@ typedef struct ace_list {
  *	returns (-1 = less than, 0 = equal, 1 = greater than
  */
 void
-ksort(caddr_t v, int n, int s, int (*f)())
+ksort(caddr_t v, int n, int s, int (*f)(void *, void *))
 {
 	int g, i, j, ii;
 	unsigned int *p1, *p2;
diff --git a/module/os/freebsd/spl/callb.c b/module/os/freebsd/spl/callb.c
index 04ea396f54..8db8e69b3b 100644
--- a/module/os/freebsd/spl/callb.c
+++ b/module/os/freebsd/spl/callb.c
@@ -52,7 +52,8 @@ typedef struct callb {
 	char		c_flag;		/* info about the callb state */
 	uchar_t		c_class;	/* this callb's class */
 	kcondvar_t	c_done_cv;	/* signal callb completion */
-	boolean_t	(*c_func)();	/* cb function: returns true if ok */
+	boolean_t	(*c_func)(void *, int);
+					/* cb function: returns true if ok */
 	void		*c_arg;		/* arg to c_func */
 	char		c_name[CB_MAXNAME+1]; /* debug:max func name length */
 } callb_t;
diff --git a/module/os/freebsd/zfs/kmod_core.c b/module/os/freebsd/zfs/kmod_core.c
index 17e9e8dff2..4a4f55ea6d 100644
--- a/module/os/freebsd/zfs/kmod_core.c
+++ b/module/os/freebsd/zfs/kmod_core.c
@@ -106,11 +106,6 @@ SYSCTL_INT(_vfs_zfs_version, OID_AUTO, ioctl, CTLFLAG_RD, &zfs_version_ioctl,
 
 static struct cdev *zfsdev;
 
-extern void zfs_init(void);
-extern void zfs_fini(void);
-extern void zfs_ioctl_init(void);
-
-
 static struct root_hold_token *zfs_root_token;
 
 extern uint_t rrw_tsd_key;
diff --git a/module/os/freebsd/zfs/spa_os.c b/module/os/freebsd/zfs/spa_os.c
index ed124a5faf..a84b8532ea 100644
--- a/module/os/freebsd/zfs/spa_os.c
+++ b/module/os/freebsd/zfs/spa_os.c
@@ -37,6 +37,7 @@
 #include <sys/zil.h>
 #include <sys/ddt.h>
 #include <sys/vdev_impl.h>
+#include <sys/vdev_os.h>
 #include <sys/vdev_removal.h>
 #include <sys/vdev_indirect_mapping.h>
 #include <sys/vdev_indirect_births.h>
@@ -72,9 +73,6 @@
 #include "zfs_prop.h"
 #include "zfs_comutil.h"
 
-extern int vdev_geom_read_pool_label(const char *name, nvlist_t ***configs,
-    uint64_t *count);
-
 static nvlist_t *
 spa_generate_rootconf(const char *name)
 {
diff --git a/module/os/freebsd/zfs/vdev_geom.c b/module/os/freebsd/zfs/vdev_geom.c
index 0efdb1be58..80fc37840c 100644
--- a/module/os/freebsd/zfs/vdev_geom.c
+++ b/module/os/freebsd/zfs/vdev_geom.c
@@ -32,6 +32,7 @@
 #include <sys/spa.h>
 #include <sys/spa_impl.h>
 #include <sys/vdev_impl.h>
+#include <sys/vdev_os.h>
 #include <sys/fs/zfs.h>
 #include <sys/zio.h>
 #include <geom/geom.h>
diff --git a/module/zfs/vdev_raidz_math.c b/module/zfs/vdev_raidz_math.c
index 14120e1106..acaa32f6dd 100644
--- a/module/zfs/vdev_raidz_math.c
+++ b/module/zfs/vdev_raidz_math.c
@@ -31,8 +31,6 @@
 #include <sys/vdev_raidz_impl.h>
 #include <sys/simd.h>
 
-extern boolean_t raidz_will_scalar_work(void);
-
 /* Opaque implementation with NULL methods to represent original methods */
 static const raidz_impl_ops_t vdev_raidz_original_impl = {
 	.name = "original",
diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index 8debed9249..4122114b56 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -222,9 +222,6 @@
 kmutex_t zfsdev_state_lock;
 zfsdev_state_t *zfsdev_state_list;
 
-extern void zfs_init(void);
-extern void zfs_fini(void);
-
 /*
  * Limit maximum nvlist size.  We don't want users passing in insane values
  * for zc->zc_nvlist_src_size, since we will need to allocate that much memory.
diff --git a/module/zfs/zfs_log.c b/module/zfs/zfs_log.c
index 6951ef90b8..4eae855f42 100644
--- a/module/zfs/zfs_log.c
+++ b/module/zfs/zfs_log.c
@@ -408,8 +408,6 @@ zfs_log_create(zilog_t *zilog, dmu_tx_t *tx, uint64_t txtype,
 	zil_itx_assign(zilog, itx, tx);
 }
 
-void zil_remove_async(zilog_t *zilog, uint64_t oid);
-
 /*
  * Handles both TX_REMOVE and TX_RMDIR transactions.
  */