--- a/usr/src/cmd/zfs/zfs_main.c	Sat Sep 01 21:48:46 2012 -0400
+++ b/usr/src/cmd/zfs/zfs_main.c	Sun Sep 09 11:37:20 2012 -0500
@@ -2288,10 +2288,8 @@
 			if (!cb->cb_sid2posix) {
 				e = directory_name_from_sid(NULL, sid, &name,
 				    &classes);
-				if (e != NULL) {
+				if (e != NULL)
 					directory_error_free(e);
-					return (1);
-				}
 				if (name == NULL)
 					name = sid;
 			}
@@ -2534,7 +2532,7 @@
 	boolean_t prtnum = B_FALSE;
 	boolean_t parsable = B_FALSE;
 	boolean_t sid2posix = B_FALSE;
-	int error = 0;
+	int ret = 0;
 	int c;
 	zfs_sort_column_t *sortcol = NULL;
 	int types = USTYPE_PSX_USR | USTYPE_SMB_USR;
@@ -2679,18 +2677,19 @@
 		    !(types & (USTYPE_PSX_GRP | USTYPE_SMB_GRP))))
 			continue;
 		cb.cb_prop = p;
-		error = zfs_userspace(zhp, p, userspace_cb, &cb);
-		if (error)
-			break;
+		if ((ret = zfs_userspace(zhp, p, userspace_cb, &cb)) != 0)
+			return (ret);
 	}
 
 	/* Sort the list */
+	if ((node = uu_avl_first(avl_tree)) == NULL)
+		return (0);
+
 	us_populated = B_TRUE;
+
 	listpool = uu_list_pool_create("tmplist", sizeof (us_node_t),
 	    offsetof(us_node_t, usn_listnode), NULL, UU_DEFAULT);
 	list = uu_list_create(listpool, NULL, UU_DEFAULT);
-
-	node = uu_avl_first(avl_tree);
 	uu_list_node_init(node, &node->usn_listnode, listpool);
 
 	while (node != NULL) {
@@ -2731,7 +2730,7 @@
 	uu_avl_destroy(avl_tree);
 	uu_avl_pool_destroy(avl_pool);
 
-	return (error);
+	return (ret);
 }
 
 /*

--- a/usr/src/lib/libzfs/common/libzfs_dataset.c	Sat Sep 01 21:48:46 2012 -0400
+++ b/usr/src/lib/libzfs/common/libzfs_dataset.c	Sun Sep 09 11:37:20 2012 -0500
@@ -21,9 +21,9 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright 2010 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2012 by Delphix. All rights reserved.
  * Copyright (c) 2012 DEY Storage Systems, Inc.  All rights reserved.
+ * Copyright 2012 Nexenta Systems, Inc. All rights reserved.
  */
 
 #include <ctype.h>
@@ -4023,35 +4023,40 @@
     zfs_userspace_cb_t func, void *arg)
 {
 	zfs_cmd_t zc = { 0 };
-	int error;
 	zfs_useracct_t buf[100];
+	libzfs_handle_t *hdl = zhp->zfs_hdl;
+	int ret;
 
 	(void) strlcpy(zc.zc_name, zhp->zfs_name, sizeof (zc.zc_name));
 
 	zc.zc_objset_type = type;
 	zc.zc_nvlist_dst = (uintptr_t)buf;
 
-	/* CONSTCOND */
-	while (1) {
+	for (;;) {
 		zfs_useracct_t *zua = buf;
 
 		zc.zc_nvlist_dst_size = sizeof (buf);
-		error = ioctl(zhp->zfs_hdl->libzfs_fd,
-		    ZFS_IOC_USERSPACE_MANY, &zc);
-		if (error || zc.zc_nvlist_dst_size == 0)
+		if (zfs_ioctl(hdl, ZFS_IOC_USERSPACE_MANY, &zc) != 0) {
+			char errbuf[ZFS_MAXNAMELEN + 32];
+
+			(void) snprintf(errbuf, sizeof (errbuf),
+			    dgettext(TEXT_DOMAIN,
+			    "cannot get used/quota for %s"), zc.zc_name);
+			return (zfs_standard_error_fmt(hdl, errno, errbuf));
+		}
+		if (zc.zc_nvlist_dst_size == 0)
 			break;
 
 		while (zc.zc_nvlist_dst_size > 0) {
-			error = func(arg, zua->zu_domain, zua->zu_rid,
-			    zua->zu_space);
-			if (error != 0)
-				return (error);
+			if ((ret = func(arg, zua->zu_domain, zua->zu_rid,
+			    zua->zu_space)) != 0)
+				return (ret);
 			zua++;
 			zc.zc_nvlist_dst_size -= sizeof (zfs_useracct_t);
 		}
 	}
 
-	return (error);
+	return (0);
 }
 
 int