svn commit: r297092 - stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Alexander Motin]

Author: mav
Date: Sun Mar 20 23:49:58 2016
New Revision: 297092
URL: https://svnweb.freebsd.org/changeset/base/297092

Log:
  MFC r294794: MFV r294793:
  6367 spa_config_tryenter incorrectly handles the multiple-lock case
  
  Reviewed by: Alek Pinchuk <alek.pinchuk at nexenta.com>
  Reviewed by: Josef 'Jeff' Sipek <josef.sipek at nexenta.com>
  Reviewed by: Prashanth Sreenivasa <prashksp at gmail.com>
  Reviewed by: Matthew Ahrens <mahrens at delphix.com>
  Reviewed by: Dan McDonald <danmcd at omniti.com>
  Reviewed by: Steven Hartland <steven.hartland at multiplay.co.uk>
  Approved by: Matthew Ahrens <mahrens at delphix.com>
  
  illumos/illumos-gate at e495b6e6735b803e422025a630352ef9bba788c5

Modified:
  stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_misc.c
Directory Properties:
  stable/10/   (props changed)

Modified: stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_misc.c
==============================================================================
--- stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_misc.c	Sun Mar 20 23:48:26 2016	(r297091)
+++ stable/10/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/spa_misc.c	Sun Mar 20 23:49:58 2016	(r297092)
@@ -21,7 +21,7 @@
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
- * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
+ * Copyright 2015 Nexenta Systems, Inc.  All rights reserved.
  * Copyright 2013 Martin Matuska <mm at FreeBSD.org>. All rights reserved.
  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
  * Copyright 2013 Saso Kiselkov. All rights reserved.
@@ -459,14 +459,16 @@ spa_config_tryenter(spa_t *spa, int lock
 		if (rw == RW_READER) {
 			if (scl->scl_writer || scl->scl_write_wanted) {
 				mutex_exit(&scl->scl_lock);
-				spa_config_exit(spa, locks ^ (1 << i), tag);
+				spa_config_exit(spa, locks & ((1 << i) - 1),
+				    tag);
 				return (0);
 			}
 		} else {
 			ASSERT(scl->scl_writer != curthread);
 			if (!refcount_is_zero(&scl->scl_count)) {
 				mutex_exit(&scl->scl_lock);
-				spa_config_exit(spa, locks ^ (1 << i), tag);
+				spa_config_exit(spa, locks & ((1 << i) - 1),
+				    tag);
 				return (0);
 			}
 			scl->scl_writer = curthread;