From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752613AbdBMNJy (ORCPT ); Mon, 13 Feb 2017 08:09:54 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:43022 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753380AbdBMNFY (ORCPT ); Mon, 13 Feb 2017 08:05:24 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Benjamin ESTRABAUD , Christoph Hellwig , Nicholas Bellinger Subject: [PATCH 4.4 07/20] target: Dont BUG_ON during NodeACL dynamic -> explicit conversion Date: Mon, 13 Feb 2017 05:04:52 -0800 Message-Id: <20170213130403.837811151@linuxfoundation.org> X-Mailer: git-send-email 2.11.1 In-Reply-To: <20170213130403.531813333@linuxfoundation.org> References: <20170213130403.531813333@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nicholas Bellinger commit 391e2a6de9781e4906dd7e0b1cc097050bf43e11 upstream. After the v4.2+ RCU conversion to se_node_acl->lun_entry_hlist, a BUG_ON() was added in core_enable_device_list_for_node() to detect when the located orig->se_lun_acl contains an existing se_lun_acl pointer reference. However, this scenario can happen when a dynamically generated NodeACL is being converted to an explicit NodeACL, when the explicit NodeACL contains a different LUN mapping than the default provided by the WWN endpoint. So instead of triggering BUG_ON(), go ahead and fail instead following the original pre RCU conversion logic. Reported-by: Benjamin ESTRABAUD Cc: Benjamin ESTRABAUD Reviewed-by: Christoph Hellwig Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/target_core_device.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/drivers/target/target_core_device.c +++ b/drivers/target/target_core_device.c @@ -362,7 +362,15 @@ int core_enable_device_list_for_node( kfree(new); return -EINVAL; } - BUG_ON(orig->se_lun_acl != NULL); + if (orig->se_lun_acl != NULL) { + pr_warn_ratelimited("Detected existing explicit" + " se_lun_acl->se_lun_group reference for %s" + " mapped_lun: %llu, failing\n", + nacl->initiatorname, mapped_lun); + mutex_unlock(&nacl->lun_entry_mutex); + kfree(new); + return -EINVAL; + } rcu_assign_pointer(new->se_lun, lun); rcu_assign_pointer(new->se_lun_acl, lun_acl);