From patchwork Mon Jan 26 20:54:27 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David L Stevens X-Patchwork-Id: 433038 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 1B9501401E7 for ; Tue, 27 Jan 2015 07:54:45 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757005AbbAZUyd (ORCPT ); Mon, 26 Jan 2015 15:54:33 -0500 Received: from aserp1040.oracle.com ([141.146.126.69]:44111 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756170AbbAZUyb (ORCPT ); Mon, 26 Jan 2015 15:54:31 -0500 Received: from ucsinet22.oracle.com (ucsinet22.oracle.com [156.151.31.94]) by aserp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id t0QKsTNW006248 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Mon, 26 Jan 2015 20:54:30 GMT Received: from aserz7022.oracle.com (aserz7022.oracle.com [141.146.126.231]) by ucsinet22.oracle.com (8.14.5+Sun/8.14.5) with ESMTP id t0QKsS55007657 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Mon, 26 Jan 2015 20:54:29 GMT Received: from abhmp0002.oracle.com (abhmp0002.oracle.com [141.146.116.8]) by aserz7022.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id t0QKsS8p013951; Mon, 26 Jan 2015 20:54:28 GMT Received: from [10.154.162.37] (/10.154.162.37) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 26 Jan 2015 12:54:28 -0800 Message-ID: <54C6A982.7030908@oracle.com> Date: Mon, 26 Jan 2015 15:54:27 -0500 From: David L Stevens Organization: Oracle Corporation User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 MIME-Version: 1.0 To: David Miller CC: netdev@vger.kernel.org, Sowmini Varadhan Subject: [PATCH 2/2 net-next] sunvnet: improve error handling when a remote crashes X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org If a remote machine crashes while there are pending transmit buffers, the sunvnet driver reallocates the ring descriptors giving us enries that have state VIO_DESC_FREE but also an allocated skb. This results in a BUG_ON() call when the remote reboots and we reach that point in the ring. This patch: 1) clears pending tx packets in the ring on port reset 2) changes a BUG_ON() to a pr_warn() when a remote host has given us an invalid descriptor state 3) collapses multiple active buffer frees in a ring to a single message per ring and adds the device name and remote MAC address This fixes the particular problem of not cleaning up pending buffers on a reset, but also prevents us from crashing if the remote handles descriptors out of order or sets an unexpected state for a descriptor. Signed-off-by: David L Stevens --- drivers/net/ethernet/sun/sunvnet.c | 62 +++++++++++++++++++---------------- 1 files changed, 34 insertions(+), 28 deletions(-) diff --git a/drivers/net/ethernet/sun/sunvnet.c b/drivers/net/ethernet/sun/sunvnet.c index fe044f3..2b719cc 100644 --- a/drivers/net/ethernet/sun/sunvnet.c +++ b/drivers/net/ethernet/sun/sunvnet.c @@ -50,6 +50,7 @@ MODULE_VERSION(DRV_MODULE_VERSION); #define VNET_MAX_RETRIES 10 static int __vnet_tx_trigger(struct vnet_port *port, u32 start); +static void vnet_port_reset(struct vnet_port *port); /* Ordered from largest major to lowest */ static struct vio_version vnet_versions[] = { @@ -736,9 +737,7 @@ ldc_ctrl: vio_link_state_change(vio, event); if (event == LDC_EVENT_RESET) { - port->rmtu = 0; - port->tso = true; - port->tsolen = 0; + vnet_port_reset(port); vio_port_up(vio); } port->rx_event = 0; @@ -934,36 +933,36 @@ static struct sk_buff *vnet_clean_tx_ring(struct vnet_port *port, *pending = 0; - txi = dr->prod-1; - if (txi < 0) - txi = VNET_TX_RING_SIZE-1; - + txi = dr->prod; for (i = 0; i < VNET_TX_RING_SIZE; ++i) { struct vio_net_desc *d; - d = vio_dring_entry(dr, txi); - - if (d->hdr.state == VIO_DESC_DONE) { - if (port->tx_bufs[txi].skb) { - BUG_ON(port->tx_bufs[txi].skb->next); + --txi; + if (txi < 0) + txi = VNET_TX_RING_SIZE-1; - port->tx_bufs[txi].skb->next = skb; - skb = port->tx_bufs[txi].skb; - port->tx_bufs[txi].skb = NULL; + d = vio_dring_entry(dr, txi); - ldc_unmap(port->vio.lp, - port->tx_bufs[txi].cookies, - port->tx_bufs[txi].ncookies); - } - d->hdr.state = VIO_DESC_FREE; - } else if (d->hdr.state == VIO_DESC_READY) { + if (d->hdr.state == VIO_DESC_READY) { (*pending)++; - } else if (d->hdr.state == VIO_DESC_FREE) { - break; + continue; } - --txi; - if (txi < 0) - txi = VNET_TX_RING_SIZE-1; + if (port->tx_bufs[txi].skb) { + if (d->hdr.state != VIO_DESC_DONE) + pr_notice("invalid ring buffer state %d\n", + d->hdr.state); + BUG_ON(port->tx_bufs[txi].skb->next); + + port->tx_bufs[txi].skb->next = skb; + skb = port->tx_bufs[txi].skb; + port->tx_bufs[txi].skb = NULL; + + ldc_unmap(port->vio.lp, + port->tx_bufs[txi].cookies, + port->tx_bufs[txi].ncookies); + } else if (d->hdr.state == VIO_DESC_FREE) + break; + d->hdr.state = VIO_DESC_FREE; } return skb; } @@ -1649,8 +1648,6 @@ static void vnet_port_free_tx_bufs(struct vnet_port *port) continue; d = vio_dring_entry(dr, i); - if (d->hdr.state == VIO_DESC_READY) - pr_warn("active transmit buffers freed\n"); ldc_unmap(port->vio.lp, port->tx_bufs[i].cookies, @@ -1669,6 +1666,15 @@ static void vnet_port_free_tx_bufs(struct vnet_port *port) dr->ncookies = 0; } +static void vnet_port_reset(struct vnet_port *port) +{ + del_timer(&port->clean_timer); + vnet_port_free_tx_bufs(port); + port->rmtu = 0; + port->tso = true; + port->tsolen = 0; +} + static int vnet_port_alloc_tx_ring(struct vnet_port *port) { struct vio_dring_state *dr;