From 9775e98844c393229183ebbbd75a877cd8a3a293 Mon Sep 17 00:00:00 2001
From: Brian Behlendorf <behlendorf1@llnl.gov>
Date: Fri, 13 Jan 2017 15:29:32 -0800
Subject: [PATCH] OpenZFS 7181 - race between zfs_mount and zfs_ioc_rollback

Authored by: Andriy Gapon <andriy.gapon@clusterhq.com>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Approved by: Gordon Ross <gordon.w.ross@gmail.com>
Reviewed-by: Richard Yao <ryao@gentoo.org>
Reviewed-by: Giuseppe Di Natale <dinatale2@llnl.gov>
Ported-by: Brian Behlendorf <behlendorf1@llnl.gov>

OpenZFS-issue: https://www.illumos.org/issues/7181
OpenZFS-commit: https://github.com/openzfs/openzfs/commit/90f2c09
Closes #5585
---
 module/zfs/zfs_vfsops.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
index 3c76cfe6ff..65efcdce5c 100644
--- a/module/zfs/zfs_vfsops.c
+++ b/module/zfs/zfs_vfsops.c
@@ -911,13 +911,6 @@ zfs_sb_setup(zfs_sb_t *zsb, boolean_t mounting)
 	if (error)
 		return (error);
 
-	/*
-	 * Set the objset user_ptr to track its zsb.
-	 */
-	mutex_enter(&zsb->z_os->os_user_ptr_lock);
-	dmu_objset_set_user(zsb->z_os, zsb);
-	mutex_exit(&zsb->z_os->os_user_ptr_lock);
-
 	zsb->z_log = zil_open(zsb->z_os, zfs_get_data);
 
 	/*
@@ -981,6 +974,13 @@ zfs_sb_setup(zfs_sb_t *zsb, boolean_t mounting)
 			readonly_changed_cb(zsb, B_TRUE);
 	}
 
+	/*
+	 * Set the objset user_ptr to track its zsb.
+	 */
+	mutex_enter(&zsb->z_os->os_user_ptr_lock);
+	dmu_objset_set_user(zsb->z_os, zsb);
+	mutex_exit(&zsb->z_os->os_user_ptr_lock);
+
 	return (0);
 }
 EXPORT_SYMBOL(zfs_sb_setup);