From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1425818AbcFHOTN (ORCPT ); Wed, 8 Jun 2016 10:19:13 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56503 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423148AbcFHOTK (ORCPT ); Wed, 8 Jun 2016 10:19:10 -0400 From: Vitaly Kuznetsov To: netdev@vger.kernel.org Cc: devel@linuxdriverproject.org, linux-kernel@vger.kernel.org, "K. Y. Srinivasan" , Haiyang Zhang Subject: [PATCH RFC net-next] netvsc: get rid of completion timeouts Date: Wed, 8 Jun 2016 16:19:06 +0200 Message-Id: <1465395546-28272-1-git-send-email-vkuznets@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 08 Jun 2016 14:19:09 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I'm hitting 5 second timeout in rndis_filter_set_rss_param() while setting RSS parameters for the device. When this happens we end up returning -ETIMEDOUT from the function and rndis_filter_device_add() falls back to setting net_device->max_chn = 1; net_device->num_chn = 1; net_device->num_sc_offered = 0; but after a moment the rndis request succeeds and subchannels start to appear. netvsc_sc_open() does unconditional nvscdev->num_sc_offered-- and it becomes U32_MAX-1. Consequent rndis_filter_device_remove() will hang while waiting for all U32_MAX-1 subchannels to appear and this is not going to happen. The immediate issue could be solved by adding num_sc_offered > 0 check to netvsc_sc_open() but we're getting out of sync with the host and it's not easy to adjust things later, e.g. in this particular case we'll be creating queues without a user request for it and races are expected. Same applies to other parts of the driver which have the same completion timeout. Following the trend in drivers/hv/* code I suggest we remove all these timeouts completely. As a guest we can always trust the host we're running on and if the host screws things up there is no easy way to recover anyway. Signed-off-by: Vitaly Kuznetsov --- drivers/net/hyperv/netvsc.c | 14 +---- drivers/net/hyperv/rndis_filter.c | 115 +++++++++----------------------------- 2 files changed, 30 insertions(+), 99 deletions(-) diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index 719cb35..89e0dea 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -249,7 +249,6 @@ static int netvsc_destroy_buf(struct hv_device *device) static int netvsc_init_buf(struct hv_device *device) { int ret = 0; - unsigned long t; struct netvsc_device *net_device; struct nvsp_message *init_packet; struct net_device *ndev; @@ -310,9 +309,7 @@ static int netvsc_init_buf(struct hv_device *device) goto cleanup; } - t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ); - BUG_ON(t == 0); - + wait_for_completion(&net_device->channel_init_wait); /* Check the response */ if (init_packet->msg.v1_msg. @@ -395,8 +392,7 @@ static int netvsc_init_buf(struct hv_device *device) goto cleanup; } - t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ); - BUG_ON(t == 0); + wait_for_completion(&net_device->channel_init_wait); /* Check the response */ if (init_packet->msg.v1_msg. @@ -450,7 +446,6 @@ static int negotiate_nvsp_ver(struct hv_device *device, { struct net_device *ndev = hv_get_drvdata(device); int ret; - unsigned long t; memset(init_packet, 0, sizeof(struct nvsp_message)); init_packet->hdr.msg_type = NVSP_MSG_TYPE_INIT; @@ -467,10 +462,7 @@ static int negotiate_nvsp_ver(struct hv_device *device, if (ret != 0) return ret; - t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ); - - if (t == 0) - return -ETIMEDOUT; + wait_for_completion(&net_device->channel_init_wait); if (init_packet->msg.init_msg.init_complete.status != NVSP_STAT_SUCCESS) diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c index 97c292b..e68c6c4 100644 --- a/drivers/net/hyperv/rndis_filter.c +++ b/drivers/net/hyperv/rndis_filter.c @@ -466,7 +466,6 @@ static int rndis_filter_query_device(struct rndis_device *dev, u32 oid, struct rndis_query_request *query; struct rndis_query_complete *query_complete; int ret = 0; - unsigned long t; if (!result) return -EINVAL; @@ -503,11 +502,7 @@ static int rndis_filter_query_device(struct rndis_device *dev, u32 oid, if (ret != 0) goto cleanup; - t = wait_for_completion_timeout(&request->wait_event, 5*HZ); - if (t == 0) { - ret = -ETIMEDOUT; - goto cleanup; - } + wait_for_completion(&request->wait_event); /* Copy the response back */ query_complete = &request->response_msg.msg.query_complete; @@ -558,7 +553,6 @@ int rndis_filter_set_device_mac(struct hv_device *hdev, char *mac) u32 extlen = sizeof(struct rndis_config_parameter_info) + 2*NWADR_STRLEN + 4*ETH_ALEN; int ret; - unsigned long t; request = get_rndis_request(rdev, RNDIS_MSG_SET, RNDIS_MESSAGE_SIZE(struct rndis_set_request) + extlen); @@ -599,21 +593,13 @@ int rndis_filter_set_device_mac(struct hv_device *hdev, char *mac) if (ret != 0) goto cleanup; - t = wait_for_completion_timeout(&request->wait_event, 5*HZ); - if (t == 0) { - netdev_err(ndev, "timeout before we got a set response...\n"); - /* - * can't put_rndis_request, since we may still receive a - * send-completion. - */ - return -EBUSY; - } else { - set_complete = &request->response_msg.msg.set_complete; - if (set_complete->status != RNDIS_STATUS_SUCCESS) { - netdev_err(ndev, "Fail to set MAC on host side:0x%x\n", - set_complete->status); - ret = -EINVAL; - } + wait_for_completion(&request->wait_event); + + set_complete = &request->response_msg.msg.set_complete; + if (set_complete->status != RNDIS_STATUS_SUCCESS) { + netdev_err(ndev, "Fail to set MAC on host side:0x%x\n", + set_complete->status); + ret = -EINVAL; } cleanup: @@ -635,7 +621,6 @@ rndis_filter_set_offload_params(struct hv_device *hdev, struct rndis_set_complete *set_complete; u32 extlen = sizeof(struct ndis_offload_params); int ret; - unsigned long t; u32 vsp_version = nvdev->nvsp_version; if (vsp_version <= NVSP_PROTOCOL_VERSION_4) { @@ -669,20 +654,12 @@ rndis_filter_set_offload_params(struct hv_device *hdev, if (ret != 0) goto cleanup; - t = wait_for_completion_timeout(&request->wait_event, 5*HZ); - if (t == 0) { - netdev_err(ndev, "timeout before we got aOFFLOAD set response...\n"); - /* can't put_rndis_request, since we may still receive a - * send-completion. - */ - return -EBUSY; - } else { - set_complete = &request->response_msg.msg.set_complete; - if (set_complete->status != RNDIS_STATUS_SUCCESS) { - netdev_err(ndev, "Fail to set offload on host side:0x%x\n", - set_complete->status); - ret = -EINVAL; - } + wait_for_completion(&request->wait_event); + set_complete = &request->response_msg.msg.set_complete; + if (set_complete->status != RNDIS_STATUS_SUCCESS) { + netdev_err(ndev, "Fail to set offload on host side:0x%x\n", + set_complete->status); + ret = -EINVAL; } cleanup: @@ -710,7 +687,6 @@ static int rndis_filter_set_rss_param(struct rndis_device *rdev, int num_queue) u32 *itab; u8 *keyp; int i, ret; - unsigned long t; request = get_rndis_request( rdev, RNDIS_MSG_SET, @@ -753,20 +729,12 @@ static int rndis_filter_set_rss_param(struct rndis_device *rdev, int num_queue) if (ret != 0) goto cleanup; - t = wait_for_completion_timeout(&request->wait_event, 5*HZ); - if (t == 0) { - netdev_err(ndev, "timeout before we got a set response...\n"); - /* can't put_rndis_request, since we may still receive a - * send-completion. - */ - return -ETIMEDOUT; - } else { - set_complete = &request->response_msg.msg.set_complete; - if (set_complete->status != RNDIS_STATUS_SUCCESS) { - netdev_err(ndev, "Fail to set RSS parameters:0x%x\n", - set_complete->status); - ret = -EINVAL; - } + wait_for_completion(&request->wait_event); + set_complete = &request->response_msg.msg.set_complete; + if (set_complete->status != RNDIS_STATUS_SUCCESS) { + netdev_err(ndev, "Fail to set RSS parameters:0x%x\n", + set_complete->status); + ret = -EINVAL; } cleanup: @@ -795,7 +763,6 @@ int rndis_filter_set_packet_filter(struct rndis_device *dev, u32 new_filter) struct rndis_set_complete *set_complete; u32 status; int ret; - unsigned long t; struct net_device *ndev = dev->ndev; request = get_rndis_request(dev, RNDIS_MSG_SET, @@ -819,26 +786,14 @@ int rndis_filter_set_packet_filter(struct rndis_device *dev, u32 new_filter) if (ret != 0) goto cleanup; - t = wait_for_completion_timeout(&request->wait_event, 5*HZ); + wait_for_completion(&request->wait_event); - if (t == 0) { - netdev_err(ndev, - "timeout before we got a set response...\n"); - ret = -ETIMEDOUT; - /* - * We can't deallocate the request since we may still receive a - * send completion for it. - */ - goto exit; - } else { - set_complete = &request->response_msg.msg.set_complete; - status = set_complete->status; - } + set_complete = &request->response_msg.msg.set_complete; + status = set_complete->status; cleanup: if (request) put_rndis_request(dev, request); -exit: return ret; } @@ -850,7 +805,6 @@ static int rndis_filter_init_device(struct rndis_device *dev) struct rndis_initialize_complete *init_complete; u32 status; int ret; - unsigned long t; struct net_device_context *net_device_ctx = netdev_priv(dev->ndev); struct netvsc_device *nvdev = net_device_ctx->nvdev; @@ -875,12 +829,7 @@ static int rndis_filter_init_device(struct rndis_device *dev) goto cleanup; } - t = wait_for_completion_timeout(&request->wait_event, 5*HZ); - - if (t == 0) { - ret = -ETIMEDOUT; - goto cleanup; - } + wait_for_completion(&request->wait_event); init_complete = &request->response_msg.msg.init_complete; status = init_complete->status; @@ -1014,7 +963,6 @@ int rndis_filter_device_add(struct hv_device *dev, struct netvsc_device_info *device_info = additional_info; struct ndis_offload_params offloads; struct nvsp_message *init_packet; - unsigned long t; struct ndis_recv_scale_cap rsscap; u32 rsscap_size = sizeof(struct ndis_recv_scale_cap); u32 mtu, size; @@ -1157,11 +1105,8 @@ int rndis_filter_device_add(struct hv_device *dev, VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (ret) goto out; - t = wait_for_completion_timeout(&net_device->channel_init_wait, 5*HZ); - if (t == 0) { - ret = -ETIMEDOUT; - goto out; - } + wait_for_completion(&net_device->channel_init_wait); + if (init_packet->msg.v5_msg.subchn_comp.status != NVSP_STAT_SUCCESS) { ret = -ENODEV; @@ -1200,17 +1145,11 @@ void rndis_filter_device_remove(struct hv_device *dev) struct net_device_context *net_device_ctx = netdev_priv(ndev); struct netvsc_device *net_dev = net_device_ctx->nvdev; struct rndis_device *rndis_dev = net_dev->extension; - unsigned long t; /* If not all subchannel offers are complete, wait for them until * completion to avoid race. */ - while (net_dev->num_sc_offered > 0) { - t = wait_for_completion_timeout(&net_dev->channel_init_wait, - 10 * HZ); - if (t == 0) - WARN(1, "Netvsc: Waiting for sub-channel processing"); - } + wait_for_completion(&net_dev->channel_init_wait); /* Halt and release the rndis device */ rndis_filter_halt_device(rndis_dev); -- 2.5.5