From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:54768 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751130AbeDTQb7 (ORCPT ); Fri, 20 Apr 2018 12:31:59 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 46AE6401DEA0 for ; Fri, 20 Apr 2018 16:31:58 +0000 (UTC) From: Mohammed Gamal To: rhkernel-list@redhat.com Cc: rhvirt-patches@redhat.com, vkuznets@redhat.com, otubo@redhat.com, cavery@redhat.com, jasowang@redhat.com, Mohammed Gamal , stable@vger.kernel.org Subject: [RHEL7.6 PATCH 22/37] Drivers: hv: vmbus: Fix a rescind issue Date: Fri, 20 Apr 2018 18:29:28 +0200 Message-Id: <1524241783-22489-23-git-send-email-mgamal@redhat.com> In-Reply-To: <1524241783-22489-1-git-send-email-mgamal@redhat.com> References: <1524241783-22489-1-git-send-email-mgamal@redhat.com> Sender: stable-owner@vger.kernel.org List-ID: The current rescind processing code will not correctly handle the case where the host immediately rescinds a channel that has been offerred. In this case, we could be blocked in the open call and since the channel is rescinded, the host will not respond and we could be blocked forever in the vmbus open call.i Fix this problem. Signed-off-by: K. Y. Srinivasan Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 7fa32e5ec28b1609abc0b797b58267f725fc3964) Signed-off-by: Mohammed Gamal --- drivers/hv/channel.c | 10 ++++++++-- drivers/hv/channel_mgmt.c | 7 ++++--- include/linux/hyperv.h | 1 + 3 files changed, 13 insertions(+), 5 deletions(-) diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c index 1c967f5..1d58986 100644 --- a/drivers/hv/channel.c +++ b/drivers/hv/channel.c @@ -659,22 +659,28 @@ void vmbus_close(struct vmbus_channel *channel) */ return; } - mutex_lock(&vmbus_connection.channel_mutex); /* * Close all the sub-channels first and then close the * primary channel. */ list_for_each_safe(cur, tmp, &channel->sc_list) { cur_channel = list_entry(cur, struct vmbus_channel, sc_list); - vmbus_close_internal(cur_channel); if (cur_channel->rescind) { + wait_for_completion(&cur_channel->rescind_event); + mutex_lock(&vmbus_connection.channel_mutex); + vmbus_close_internal(cur_channel); hv_process_channel_removal( cur_channel->offermsg.child_relid); + } else { + mutex_lock(&vmbus_connection.channel_mutex); + vmbus_close_internal(cur_channel); } + mutex_unlock(&vmbus_connection.channel_mutex); } /* * Now close the primary. */ + mutex_lock(&vmbus_connection.channel_mutex); vmbus_close_internal(channel); mutex_unlock(&vmbus_connection.channel_mutex); } diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index ec5454f..c21020b 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -333,6 +333,7 @@ static struct vmbus_channel *alloc_channel(void) return NULL; spin_lock_init(&channel->lock); + init_completion(&channel->rescind_event); INIT_LIST_HEAD(&channel->sc_list); INIT_LIST_HEAD(&channel->percpu_list); @@ -898,6 +899,7 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) /* * Now wait for offer handling to complete. */ + vmbus_rescind_cleanup(channel); while (READ_ONCE(channel->probe_done) == false) { /* * We wait here until any channel offer is currently @@ -913,7 +915,6 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) if (channel->device_obj) { if (channel->chn_rescind_callback) { channel->chn_rescind_callback(channel); - vmbus_rescind_cleanup(channel); return; } /* @@ -922,7 +923,6 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) */ dev = get_device(&channel->device_obj->device); if (dev) { - vmbus_rescind_cleanup(channel); vmbus_device_unregister(channel->device_obj); put_device(dev); } @@ -936,13 +936,14 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) * 2. Then close the primary channel. */ mutex_lock(&vmbus_connection.channel_mutex); - vmbus_rescind_cleanup(channel); if (channel->state == CHANNEL_OPEN_STATE) { /* * The channel is currently not open; * it is safe for us to cleanup the channel. */ hv_process_channel_removal(rescind->child_relid); + } else { + complete(&channel->rescind_event); } mutex_unlock(&vmbus_connection.channel_mutex); } diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h index 1552a5f..465d5db 100644 --- a/include/linux/hyperv.h +++ b/include/linux/hyperv.h @@ -724,6 +724,7 @@ struct vmbus_channel { u8 monitor_bit; bool rescind; /* got rescind msg */ + struct completion rescind_event; u32 ringbuffer_gpadlhandle; -- 1.8.3.1