7541 zpool import/tryimport ioctl returns ENOMEM because provided buf…

…fer is too small for config

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>

usr/src/lib/libzfs/common/libzfs_impl.h

@@ -130,6 +130,8 @@ typedef enum {
 	SHARED_SMB = 0x4
 } zfs_share_type_t;
 
+#define	CONFIG_BUF_MINSIZE	65536
+
 int zfs_error(libzfs_handle_t *, int, const char *);
 int zfs_error_fmt(libzfs_handle_t *, int, const char *, ...);
 void zfs_error_aux(libzfs_handle_t *, const char *, ...);

usr/src/lib/libzfs/common/libzfs_import.c

@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
+ * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
  * Copyright 2015 RackTop Systems.
  * Copyright 2016 Nexenta Systems, Inc.
  */
@@ -380,13 +380,14 @@ refresh_config(libzfs_handle_t *hdl, nvlist_t *config)
 {
 	nvlist_t *nvl;
 	zfs_cmd_t zc = { 0 };
-	int err;
+	int err, dstbuf_size;
 
 	if (zcmd_write_conf_nvlist(hdl, &zc, config) != 0)
 		return (NULL);
 
-	if (zcmd_alloc_dst_nvlist(hdl, &zc,
-	    zc.zc_nvlist_conf_size * 2) != 0) {
+	dstbuf_size = MAX(CONFIG_BUF_MINSIZE, zc.zc_nvlist_conf_size * 4);
+
+	if (zcmd_alloc_dst_nvlist(hdl, &zc, dstbuf_size) != 0) {
 		zcmd_free_nvlists(&zc);
 		return (NULL);
 	}