From patchwork Thu Sep 3 16:49:55 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sagi Grimberg X-Patchwork-Id: 7117841 Return-Path: X-Original-To: patchwork-linux-scsi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3BDCFBEEC1 for ; Thu, 3 Sep 2015 16:50:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4A55D20734 for ; Thu, 3 Sep 2015 16:50:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 53D7820732 for ; Thu, 3 Sep 2015 16:50:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752630AbbICQuS (ORCPT ); Thu, 3 Sep 2015 12:50:18 -0400 Received: from [193.47.165.129] ([193.47.165.129]:60950 "EHLO mellanox.co.il" rhost-flags-FAIL-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1752599AbbICQuR (ORCPT ); Thu, 3 Sep 2015 12:50:17 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from sagig@mellanox.com) with ESMTPS (AES256-SHA encrypted); 3 Sep 2015 19:50:01 +0300 Received: from r-vnc05.mtr.labs.mlnx (r-vnc05.mtr.labs.mlnx [10.208.0.115]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id t83GntWG008928; Thu, 3 Sep 2015 19:49:55 +0300 Received: from r-vnc05.mtr.labs.mlnx (localhost [127.0.0.1]) by r-vnc05.mtr.labs.mlnx (8.14.4/8.14.4) with ESMTP id t83Gnt7m027962; Thu, 3 Sep 2015 19:49:55 +0300 Received: (from sagig@localhost) by r-vnc05.mtr.labs.mlnx (8.14.4/8.14.4/Submit) id t83GntAY027961; Thu, 3 Sep 2015 19:49:55 +0300 From: Sagi Grimberg To: James Bottomley Cc: linux-scsi@vger.kernel.org, Ariel Nahum Subject: [PATCH RESEND] libiscsi: Fix iscsi_check_transport_timeouts possible infinite loop Date: Thu, 3 Sep 2015 19:49:55 +0300 Message-Id: <1441298995-27927-1-git-send-email-sagig@mellanox.com> X-Mailer: git-send-email 1.8.4.3 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Ariel Nahum Connection last_ping is not being updated when iscsi_send_nopout fails. Not updating the last_ping will cause firing a timer to a past time (last_ping + ping_tmo < current_time) which triggers an infinite loop of iscsi_check_transport_timeouts() and hogs the cpu. Fix this issue by checking the return value of iscsi_send_nopout. If it fails set the next_timeout to one second later. Signed-off-by: Ariel Nahum Signed-off-by: Sagi Grimberg Reviewed-by: Mike Christie --- drivers/scsi/libiscsi.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 8053f24..29c02b8 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -979,13 +979,13 @@ static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr) wake_up(&conn->ehwait); } -static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr) +static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr) { struct iscsi_nopout hdr; struct iscsi_task *task; if (!rhdr && conn->ping_task) - return; + return -EINVAL; memset(&hdr, 0, sizeof(struct iscsi_nopout)); hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE; @@ -999,13 +999,16 @@ static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr) hdr.ttt = RESERVED_ITT; task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0); - if (!task) + if (!task) { iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n"); - else if (!rhdr) { + return -EIO; + } else if (!rhdr) { /* only track our nops */ conn->ping_task = task; conn->last_ping = jiffies; } + + return 0; } static int iscsi_nop_out_rsp(struct iscsi_task *task, @@ -2095,8 +2098,10 @@ static void iscsi_check_transport_timeouts(unsigned long data) if (time_before_eq(last_recv + recv_timeout, jiffies)) { /* send a ping to try to provoke some traffic */ ISCSI_DBG_CONN(conn, "Sending nopout as ping\n"); - iscsi_send_nopout(conn, NULL); - next_timeout = conn->last_ping + (conn->ping_timeout * HZ); + if (iscsi_send_nopout(conn, NULL)) + next_timeout = jiffies + (1 * HZ); + else + next_timeout = conn->last_ping + (conn->ping_timeout * HZ); } else next_timeout = last_recv + recv_timeout;