diff --git a/include/os/freebsd/zfs/sys/zfs_vfsops_os.h b/include/os/freebsd/zfs/sys/zfs_vfsops_os.h
index 24bb03575f..7f0f24325d 100644
--- a/include/os/freebsd/zfs/sys/zfs_vfsops_os.h
+++ b/include/os/freebsd/zfs/sys/zfs_vfsops_os.h
@@ -284,7 +284,6 @@ 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 uint_t zfs_fsyncer_key;
 extern int zfs_super_owner;
 
 extern void zfs_init(void);
diff --git a/include/sys/zfs_ioctl.h b/include/sys/zfs_ioctl.h
index 91439d4b78..26dfe97604 100644
--- a/include/sys/zfs_ioctl.h
+++ b/include/sys/zfs_ioctl.h
@@ -575,7 +575,6 @@ typedef struct zfsdev_state {
 extern void *zfsdev_get_state(minor_t minor, enum zfsdev_state_type which);
 extern int zfsdev_getminor(zfs_file_t *fp, minor_t *minorp);
 
-extern uint_t zfs_fsyncer_key;
 extern uint_t zfs_allow_log_key;
 
 #endif	/* _KERNEL */
diff --git a/include/sys/zfs_znode.h b/include/sys/zfs_znode.h
index 2f266f5324..d71144807f 100644
--- a/include/sys/zfs_znode.h
+++ b/include/sys/zfs_znode.h
@@ -307,7 +307,7 @@ extern void zfs_log_rename_whiteout(zilog_t *zilog, dmu_tx_t *tx,
     uint64_t txtype, znode_t *sdzp, const char *sname, znode_t *tdzp,
     const char *dname, znode_t *szp, znode_t *wzp);
 extern void zfs_log_write(zilog_t *zilog, dmu_tx_t *tx, int txtype,
-    znode_t *zp, offset_t off, ssize_t len, int ioflag,
+    znode_t *zp, offset_t off, ssize_t len, boolean_t commit,
     zil_callback_t callback, void *callback_data);
 extern void zfs_log_truncate(zilog_t *zilog, dmu_tx_t *tx, int txtype,
     znode_t *zp, uint64_t off, uint64_t len);
diff --git a/include/sys/zvol_impl.h b/include/sys/zvol_impl.h
index 3243917bcd..8103208622 100644
--- a/include/sys/zvol_impl.h
+++ b/include/sys/zvol_impl.h
@@ -81,9 +81,9 @@ void zvol_remove_minors_impl(const char *name);
 void zvol_last_close(zvol_state_t *zv);
 void zvol_insert(zvol_state_t *zv);
 void zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off,
-    uint64_t len, boolean_t sync);
+    uint64_t len);
 void zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, uint64_t offset,
-    uint64_t size, int sync);
+    uint64_t size, boolean_t commit);
 int zvol_get_data(void *arg, uint64_t arg2, lr_write_t *lr, char *buf,
     struct lwb *lwb, zio_t *zio);
 int zvol_init_impl(void);
diff --git a/module/os/freebsd/zfs/zfs_vnops_os.c b/module/os/freebsd/zfs/zfs_vnops_os.c
index ab72e91b4f..c37f543cea 100644
--- a/module/os/freebsd/zfs/zfs_vnops_os.c
+++ b/module/os/freebsd/zfs/zfs_vnops_os.c
@@ -244,9 +244,15 @@ zfs_open(vnode_t **vpp, int flag, cred_t *cr)
 		return (SET_ERROR(EPERM));
 	}
 
-	/* Keep a count of the synchronous opens in the znode */
-	if (flag & O_SYNC)
-		atomic_inc_32(&zp->z_sync_cnt);
+	/*
+	 * Keep a count of the synchronous opens in the znode.  On first
+	 * synchronous open we must convert all previous async transactions
+	 * into sync to keep correct ordering.
+	 */
+	if (flag & O_SYNC) {
+		if (atomic_inc_32_nv(&zp->z_sync_cnt) == 1)
+			zil_async_to_sync(zfsvfs->z_log, zp->z_id);
+	}
 
 	zfs_exit(zfsvfs, FTAG);
 	return (0);
@@ -4201,6 +4207,10 @@ zfs_putpages(struct vnode *vp, vm_page_t *ma, size_t len, int flags,
 	}
 	zfs_vmobject_wunlock(object);
 
+	boolean_t commit = (flags & (zfs_vm_pagerput_sync |
+	    zfs_vm_pagerput_inval)) != 0 ||
+	    zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS;
+
 	if (ncount == 0)
 		goto out;
 
@@ -4253,7 +4263,7 @@ zfs_putpages(struct vnode *vp, vm_page_t *ma, size_t len, int flags,
 		 * but that would make the locking messier
 		 */
 		zfs_log_write(zfsvfs->z_log, tx, TX_WRITE, zp, off,
-		    len, 0, NULL, NULL);
+		    len, commit, NULL, NULL);
 
 		zfs_vmobject_wlock(object);
 		for (i = 0; i < ncount; i++) {
@@ -4268,8 +4278,7 @@ zfs_putpages(struct vnode *vp, vm_page_t *ma, size_t len, int flags,
 
 out:
 	zfs_rangelock_exit(lr);
-	if ((flags & (zfs_vm_pagerput_sync | zfs_vm_pagerput_inval)) != 0 ||
-	    zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
+	if (commit)
 		zil_commit(zfsvfs->z_log, zp->z_id);
 
 	dataset_kstats_update_write_kstats(&zfsvfs->z_kstat, len);
diff --git a/module/os/freebsd/zfs/zvol_os.c b/module/os/freebsd/zfs/zvol_os.c
index 2520507b98..0830e1c265 100644
--- a/module/os/freebsd/zfs/zvol_os.c
+++ b/module/os/freebsd/zfs/zvol_os.c
@@ -123,7 +123,6 @@ struct zvol_state_os {
 		/* volmode=dev */
 		struct zvol_state_dev {
 			struct cdev *zsd_cdev;
-			uint64_t zsd_sync_cnt;
 			struct selinfo zsd_selinfo;
 		} _zso_dev;
 
@@ -669,7 +668,7 @@ zvol_geom_bio_strategy(struct bio *bp)
 	int error = 0;
 	boolean_t doread = B_FALSE;
 	boolean_t is_dumpified;
-	boolean_t sync;
+	boolean_t commit;
 
 	if (bp->bio_to)
 		zv = bp->bio_to->private;
@@ -696,7 +695,7 @@ zvol_geom_bio_strategy(struct bio *bp)
 		}
 		zvol_ensure_zilog(zv);
 		if (bp->bio_cmd == BIO_FLUSH)
-			goto sync;
+			goto commit;
 		break;
 	default:
 		error = SET_ERROR(EOPNOTSUPP);
@@ -718,7 +717,7 @@ zvol_geom_bio_strategy(struct bio *bp)
 	}
 
 	is_dumpified = B_FALSE;
-	sync = !doread && !is_dumpified &&
+	commit = !doread && !is_dumpified &&
 	    zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS;
 
 	/*
@@ -734,7 +733,7 @@ zvol_geom_bio_strategy(struct bio *bp)
 		if (error != 0) {
 			dmu_tx_abort(tx);
 		} else {
-			zvol_log_truncate(zv, tx, off, resid, sync);
+			zvol_log_truncate(zv, tx, off, resid);
 			dmu_tx_commit(tx);
 			error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ,
 			    off, resid);
@@ -755,7 +754,7 @@ zvol_geom_bio_strategy(struct bio *bp)
 				dmu_tx_abort(tx);
 			} else {
 				dmu_write(os, ZVOL_OBJ, off, size, addr, tx);
-				zvol_log_write(zv, tx, off, size, sync);
+				zvol_log_write(zv, tx, off, size, commit);
 				dmu_tx_commit(tx);
 			}
 		}
@@ -793,8 +792,8 @@ unlock:
 		break;
 	}
 
-	if (sync) {
-sync:
+	if (commit) {
+commit:
 		zil_commit(zv->zv_zilog, ZVOL_OBJ);
 	}
 resume:
@@ -866,7 +865,7 @@ zvol_cdev_write(struct cdev *dev, struct uio *uio_s, int ioflag)
 	uint64_t volsize;
 	zfs_locked_range_t *lr;
 	int error = 0;
-	boolean_t sync;
+	boolean_t commit;
 	zfs_uio_t uio;
 
 	zv = dev->si_drv2;
@@ -880,7 +879,7 @@ zvol_cdev_write(struct cdev *dev, struct uio *uio_s, int ioflag)
 		return (SET_ERROR(EIO));
 
 	ssize_t start_resid = zfs_uio_resid(&uio);
-	sync = (ioflag & IO_SYNC) ||
+	commit = (ioflag & IO_SYNC) ||
 	    (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
 
 	rw_enter(&zv->zv_suspend_lock, ZVOL_RW_READER);
@@ -904,7 +903,7 @@ zvol_cdev_write(struct cdev *dev, struct uio *uio_s, int ioflag)
 		}
 		error = dmu_write_uio_dnode(zv->zv_dn, &uio, bytes, tx);
 		if (error == 0)
-			zvol_log_write(zv, tx, off, bytes, sync);
+			zvol_log_write(zv, tx, off, bytes, commit);
 		dmu_tx_commit(tx);
 
 		if (error)
@@ -913,7 +912,7 @@ zvol_cdev_write(struct cdev *dev, struct uio *uio_s, int ioflag)
 	zfs_rangelock_exit(lr);
 	int64_t nwritten = start_resid - zfs_uio_resid(&uio);
 	dataset_kstats_update_write_kstats(&zv->zv_kstat, nwritten);
-	if (sync)
+	if (commit)
 		zil_commit(zv->zv_zilog, ZVOL_OBJ);
 	rw_exit(&zv->zv_suspend_lock);
 	return (error);
@@ -923,7 +922,6 @@ static int
 zvol_cdev_open(struct cdev *dev, int flags, int fmt, struct thread *td)
 {
 	zvol_state_t *zv;
-	struct zvol_state_dev *zsd;
 	int err = 0;
 	boolean_t drop_suspend = B_FALSE;
 
@@ -1017,13 +1015,6 @@ retry:
 	}
 
 	zv->zv_open_count++;
-	if (flags & O_SYNC) {
-		zsd = &zv->zv_zso->zso_dev;
-		zsd->zsd_sync_cnt++;
-		if (zsd->zsd_sync_cnt == 1 &&
-		    (zv->zv_flags & ZVOL_WRITTEN_TO) != 0)
-			zil_async_to_sync(zv->zv_zilog, ZVOL_OBJ);
-	}
 out_opened:
 	if (zv->zv_open_count == 0) {
 		zvol_last_close(zv);
@@ -1041,7 +1032,6 @@ static int
 zvol_cdev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
 {
 	zvol_state_t *zv;
-	struct zvol_state_dev *zsd;
 	boolean_t drop_suspend = B_TRUE;
 
 	rw_enter(&zvol_state_lock, ZVOL_RW_READER);
@@ -1091,10 +1081,6 @@ zvol_cdev_close(struct cdev *dev, int flags, int fmt, struct thread *td)
 	 * You may get multiple opens, but only one close.
 	 */
 	zv->zv_open_count--;
-	if (flags & O_SYNC) {
-		zsd = &zv->zv_zso->zso_dev;
-		zsd->zsd_sync_cnt--;
-	}
 
 	if (zv->zv_open_count == 0) {
 		ASSERT(ZVOL_RW_READ_HELD(&zv->zv_suspend_lock));
@@ -1163,7 +1149,7 @@ zvol_cdev_ioctl(struct cdev *dev, ulong_t cmd, caddr_t data,
 			dmu_tx_abort(tx);
 		} else {
 			sync = (zv->zv_objset->os_sync == ZFS_SYNC_ALWAYS);
-			zvol_log_truncate(zv, tx, offset, length, sync);
+			zvol_log_truncate(zv, tx, offset, length);
 			dmu_tx_commit(tx);
 			error = dmu_free_long_range(zv->zv_objset, ZVOL_OBJ,
 			    offset, length);
diff --git a/module/os/linux/zfs/zfs_vnops_os.c b/module/os/linux/zfs/zfs_vnops_os.c
index 1770e23725..6ad75ace0b 100644
--- a/module/os/linux/zfs/zfs_vnops_os.c
+++ b/module/os/linux/zfs/zfs_vnops_os.c
@@ -192,9 +192,15 @@ zfs_open(struct inode *ip, int mode, int flag, cred_t *cr)
 		return (SET_ERROR(EPERM));
 	}
 
-	/* Keep a count of the synchronous opens in the znode */
-	if (flag & O_SYNC)
-		atomic_inc_32(&zp->z_sync_cnt);
+	/*
+	 * Keep a count of the synchronous opens in the znode.  On first
+	 * synchronous open we must convert all previous async transactions
+	 * into sync to keep correct ordering.
+	 */
+	if (flag & O_SYNC) {
+		if (atomic_inc_32_nv(&zp->z_sync_cnt) == 1)
+			zil_async_to_sync(zfsvfs->z_log, zp->z_id);
+	}
 
 	zfs_exit(zfsvfs, FTAG);
 	return (0);
@@ -3826,21 +3832,14 @@ zfs_putpage(struct inode *ip, struct page *pp, struct writeback_control *wbc,
 
 	err = sa_bulk_update(zp->z_sa_hdl, bulk, cnt, tx);
 
-	zfs_log_write(zfsvfs->z_log, tx, TX_WRITE, zp, pgoff, pglen, 0,
-	    for_sync ? zfs_putpage_sync_commit_cb :
-	    zfs_putpage_async_commit_cb, pp);
-
-	dmu_tx_commit(tx);
-
-	zfs_rangelock_exit(lr);
-
+	boolean_t commit = B_FALSE;
 	if (wbc->sync_mode != WB_SYNC_NONE) {
 		/*
 		 * Note that this is rarely called under writepages(), because
 		 * writepages() normally handles the entire commit for
 		 * performance reasons.
 		 */
-		zil_commit(zfsvfs->z_log, zp->z_id);
+		commit = B_TRUE;
 	} else if (!for_sync && atomic_load_32(&zp->z_sync_writes_cnt) > 0) {
 		/*
 		 * If the caller does not intend to wait synchronously
@@ -3850,9 +3849,20 @@ zfs_putpage(struct inode *ip, struct page *pp, struct writeback_control *wbc,
 		 * our writeback to complete. Refer to the comment in
 		 * zpl_fsync() (when HAVE_FSYNC_RANGE is defined) for details.
 		 */
-		zil_commit(zfsvfs->z_log, zp->z_id);
+		commit = B_TRUE;
 	}
 
+	zfs_log_write(zfsvfs->z_log, tx, TX_WRITE, zp, pgoff, pglen, commit,
+	    for_sync ? zfs_putpage_sync_commit_cb :
+	    zfs_putpage_async_commit_cb, pp);
+
+	dmu_tx_commit(tx);
+
+	zfs_rangelock_exit(lr);
+
+	if (commit)
+		zil_commit(zfsvfs->z_log, zp->z_id);
+
 	dataset_kstats_update_write_kstats(&zfsvfs->z_kstat, pglen);
 
 	zfs_exit(zfsvfs, FTAG);
diff --git a/module/os/linux/zfs/zvol_os.c b/module/os/linux/zfs/zvol_os.c
index f94ce69fb9..3dc0bb3883 100644
--- a/module/os/linux/zfs/zvol_os.c
+++ b/module/os/linux/zfs/zvol_os.c
@@ -387,7 +387,7 @@ zvol_discard(zv_request_t *zvr)
 	if (error != 0) {
 		dmu_tx_abort(tx);
 	} else {
-		zvol_log_truncate(zv, tx, start, size, B_TRUE);
+		zvol_log_truncate(zv, tx, start, size);
 		dmu_tx_commit(tx);
 		error = dmu_free_long_range(zv->zv_objset,
 		    ZVOL_OBJ, start, size);
diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index 2738385e26..bfada28947 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -238,7 +238,6 @@ uint64_t zfs_max_nvlist_src_size = 0;
  */
 static uint64_t zfs_history_output_max = 1024 * 1024;
 
-uint_t zfs_fsyncer_key;
 uint_t zfs_allow_log_key;
 
 /* DATA_TYPE_ANY is used when zkey_type can vary. */
@@ -7882,7 +7881,6 @@ zfs_kmod_init(void)
 	if ((error = zfsdev_attach()) != 0)
 		goto out;
 
-	tsd_create(&zfs_fsyncer_key, NULL);
 	tsd_create(&rrw_tsd_key, rrw_tsd_destroy);
 	tsd_create(&zfs_allow_log_key, zfs_allow_log_destroy);
 
@@ -7919,7 +7917,6 @@ zfs_kmod_fini(void)
 	spa_fini();
 	zvol_fini();
 
-	tsd_destroy(&zfs_fsyncer_key);
 	tsd_destroy(&rrw_tsd_key);
 	tsd_destroy(&zfs_allow_log_key);
 }
diff --git a/module/zfs/zfs_log.c b/module/zfs/zfs_log.c
index 50325907b0..433a653e55 100644
--- a/module/zfs/zfs_log.c
+++ b/module/zfs/zfs_log.c
@@ -606,13 +606,12 @@ static int64_t zfs_immediate_write_sz = 32768;
 
 void
 zfs_log_write(zilog_t *zilog, dmu_tx_t *tx, int txtype,
-    znode_t *zp, offset_t off, ssize_t resid, int ioflag,
+    znode_t *zp, offset_t off, ssize_t resid, boolean_t commit,
     zil_callback_t callback, void *callback_data)
 {
 	dmu_buf_impl_t *db = (dmu_buf_impl_t *)sa_get_db(zp->z_sa_hdl);
 	uint32_t blocksize = zp->z_blksz;
 	itx_wr_state_t write_state;
-	uintptr_t fsync_cnt;
 	uint64_t gen = 0;
 	ssize_t size = resid;
 
@@ -628,15 +627,11 @@ zfs_log_write(zilog_t *zilog, dmu_tx_t *tx, int txtype,
 	else if (!spa_has_slogs(zilog->zl_spa) &&
 	    resid >= zfs_immediate_write_sz)
 		write_state = WR_INDIRECT;
-	else if (ioflag & (O_SYNC | O_DSYNC))
+	else if (commit)
 		write_state = WR_COPIED;
 	else
 		write_state = WR_NEED_COPY;
 
-	if ((fsync_cnt = (uintptr_t)tsd_get(zfs_fsyncer_key)) != 0) {
-		(void) tsd_set(zfs_fsyncer_key, (void *)(fsync_cnt - 1));
-	}
-
 	(void) sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(ZTOZSB(zp)), &gen,
 	    sizeof (gen));
 
@@ -687,12 +682,9 @@ zfs_log_write(zilog_t *zilog, dmu_tx_t *tx, int txtype,
 		BP_ZERO(&lr->lr_blkptr);
 
 		itx->itx_private = ZTOZSB(zp);
+		itx->itx_sync = (zp->z_sync_cnt != 0);
 		itx->itx_gen = gen;
 
-		if (!(ioflag & (O_SYNC | O_DSYNC)) && (zp->z_sync_cnt == 0) &&
-		    (fsync_cnt == 0))
-			itx->itx_sync = B_FALSE;
-
 		itx->itx_callback = callback;
 		itx->itx_callback_data = callback_data;
 		zil_itx_assign(zilog, itx, tx);
diff --git a/module/zfs/zfs_vnops.c b/module/zfs/zfs_vnops.c
index 40d6c87a75..2d0d858cda 100644
--- a/module/zfs/zfs_vnops.c
+++ b/module/zfs/zfs_vnops.c
@@ -58,27 +58,20 @@
 #include <sys/zfs_znode.h>
 
 
-static ulong_t zfs_fsync_sync_cnt = 4;
-
 int
 zfs_fsync(znode_t *zp, int syncflag, cred_t *cr)
 {
 	int error = 0;
 	zfsvfs_t *zfsvfs = ZTOZSB(zp);
 
-	(void) tsd_set(zfs_fsyncer_key, (void *)(uintptr_t)zfs_fsync_sync_cnt);
-
 	if (zfsvfs->z_os->os_sync != ZFS_SYNC_DISABLED) {
 		if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
-			goto out;
+			return (error);
 		atomic_inc_32(&zp->z_sync_writes_cnt);
 		zil_commit(zfsvfs->z_log, zp->z_id);
 		atomic_dec_32(&zp->z_sync_writes_cnt);
 		zfs_exit(zfsvfs, FTAG);
 	}
-out:
-	tsd_set(zfs_fsyncer_key, NULL);
-
 	return (error);
 }
 
@@ -520,6 +513,8 @@ zfs_write(znode_t *zp, zfs_uio_t *uio, int ioflag, cred_t *cr)
 
 	uint64_t end_size = MAX(zp->z_size, woff + n);
 	zilog_t *zilog = zfsvfs->z_log;
+	boolean_t commit = (ioflag & (O_SYNC | O_DSYNC)) ||
+	    (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS);
 
 	const uint64_t uid = KUID_TO_SUID(ZTOUID(zp));
 	const uint64_t gid = KGID_TO_SGID(ZTOGID(zp));
@@ -741,7 +736,7 @@ zfs_write(znode_t *zp, zfs_uio_t *uio, int ioflag, cred_t *cr)
 		 * zfs_clear_setid_bits_if_necessary must precede any of
 		 * the TX_WRITE records logged here.
 		 */
-		zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, ioflag,
+		zfs_log_write(zilog, tx, TX_WRITE, zp, woff, tx_bytes, commit,
 		    NULL, NULL);
 
 		dmu_tx_commit(tx);
@@ -767,8 +762,7 @@ zfs_write(znode_t *zp, zfs_uio_t *uio, int ioflag, cred_t *cr)
 		return (error);
 	}
 
-	if (ioflag & (O_SYNC | O_DSYNC) ||
-	    zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
+	if (commit)
 		zil_commit(zilog, zp->z_id);
 
 	const int64_t nwritten = start_resid - zfs_uio_resid(uio);
diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c
index cc11fd8061..28f8510bef 100644
--- a/module/zfs/zvol.c
+++ b/module/zfs/zvol.c
@@ -583,7 +583,7 @@ static const ssize_t zvol_immediate_write_sz = 32768;
 
 void
 zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, uint64_t offset,
-    uint64_t size, int sync)
+    uint64_t size, boolean_t commit)
 {
 	uint32_t blocksize = zv->zv_volblocksize;
 	zilog_t *zilog = zv->zv_zilog;
@@ -598,7 +598,7 @@ zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, uint64_t offset,
 	else if (!spa_has_slogs(zilog->zl_spa) &&
 	    size >= blocksize && blocksize > zvol_immediate_write_sz)
 		write_state = WR_INDIRECT;
-	else if (sync)
+	else if (commit)
 		write_state = WR_COPIED;
 	else
 		write_state = WR_NEED_COPY;
@@ -633,7 +633,6 @@ zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, uint64_t offset,
 		BP_ZERO(&lr->lr_blkptr);
 
 		itx->itx_private = zv;
-		itx->itx_sync = sync;
 
 		(void) zil_itx_assign(zilog, itx, tx);
 
@@ -650,8 +649,7 @@ zvol_log_write(zvol_state_t *zv, dmu_tx_t *tx, uint64_t offset,
  * Log a DKIOCFREE/free-long-range to the ZIL with TX_TRUNCATE.
  */
 void
-zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
-    boolean_t sync)
+zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len)
 {
 	itx_t *itx;
 	lr_truncate_t *lr;
@@ -666,7 +664,6 @@ zvol_log_truncate(zvol_state_t *zv, dmu_tx_t *tx, uint64_t off, uint64_t len,
 	lr->lr_offset = off;
 	lr->lr_length = len;
 
-	itx->itx_sync = sync;
 	zil_itx_assign(zilog, itx, tx);
 }