Illumos 4626 - libzfs memleak in zpool_in_use()

4626 libzfs memleak in zpool_in_use()
Reviewed by: Tony Nguyen <tony.nguyen@nexenta.com>
Reviewed by: Saso Kiselkov <saso.kiselkov@nexenta.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Approved by: Dan McDonald <danmcd@omniti.com>

References:
  illumos/illumos-gate@fb13f48
  https://www.illumos.org/issues/4626

Ported-by: kernelOfTruth kerneloftruth@gmail.com
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #3563

Author: Josef 'Jeff' Sipek

lib/libzfs/libzfs_import.c

@@ -20,8 +20,8 @@
  */
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
  * Copyright (c) 2012 by Delphix. All rights reserved.
+ * Copyright 2014 Nexenta Systems, Inc. All rights reserved.
  */
 
 /*
@@ -1532,9 +1532,16 @@ zpool_in_use(libzfs_handle_t *hdl, int fd, pool_state_t *state, char **namestr,
 		 * its state to active.
 		 */
 		if (pool_active(hdl, name, guid, &isactive) == 0 && isactive &&
-		    (zhp = zpool_open_canfail(hdl, name)) != NULL &&
-		    zpool_get_prop_int(zhp, ZPOOL_PROP_READONLY, NULL))
-			stateval = POOL_STATE_ACTIVE;
+		    (zhp = zpool_open_canfail(hdl, name)) != NULL) {
+			if (zpool_get_prop_int(zhp, ZPOOL_PROP_READONLY, NULL))
+				stateval = POOL_STATE_ACTIVE;
+
+			/*
+			 * All we needed the zpool handle for is the
+			 * readonly prop check.
+			 */
+			zpool_close(zhp);
+		}
 
 		ret = B_TRUE;
 		break;