Index: sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
===================================================================
--- sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
+++ sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_vfsops.c
@@ -1717,9 +1717,19 @@
 	 * according to those options set in the current VFS options.
 	 */
 	if (vfsp->vfs_flag & MS_REMOUNT) {
-		/* refresh mount options */
-		zfs_unregister_callbacks(vfsp->vfs_data);
+		zfsvfs_t *zfsvfs = vfsp->vfs_data;
+
+		/*
+		 * Refresh mount options with z_teardown_lock blocking I/O while
+		 * the filesystem is in an inconsistent state.
+		 * The lock also serializes this code with filesystem
+		 * manipulations between entry to zfs_suspend_fs() and return
+		 * from zfs_resume_fs().
+		 */
+		rrm_enter(&zfsvfs->z_teardown_lock, RW_WRITER, FTAG);
+		zfs_unregister_callbacks(zfsvfs);
 		error = zfs_register_callbacks(vfsp);
+		rrm_exit(&zfsvfs->z_teardown_lock, FTAG);
 		goto out;
 	}