From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751356AbdB1H4i (ORCPT ); Tue, 28 Feb 2017 02:56:38 -0500 Received: from a2nlsmtp01-03.prod.iad2.secureserver.net ([198.71.225.37]:56750 "EHLO a2nlsmtp01-03.prod.iad2.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751457AbdB1Hzh (ORCPT ); Tue, 28 Feb 2017 02:55:37 -0500 x-originating-ip: 107.180.71.197 From: kys@exchange.microsoft.com To: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, olaf@aepfle.de, apw@canonical.com, vkuznets@redhat.com, jasowang@redhat.com, leann.ogasawara@canonical.com Cc: Dexuan Cui , "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger Subject: [PATCH 1/1] Drivers: hv: util: on deinit, don't wait the release event, if we shouldn't Date: Mon, 27 Feb 2017 16:18:02 -0700 Message-Id: <1488237482-23910-1-git-send-email-kys@exchange.microsoft.com> X-Mailer: git-send-email 1.7.1 Reply-To: kys@microsoft.com X-CMAE-Envelope: MS4wfIB84VsKlwGMRu2Zvg7WC6jVcYkLPqHz/LjDkdjaBfAV8tzjvuDypKf+Irp31d3b+p6w3rVhLWMgFfNzPjSpR30yx53peD4tZxJBov4JoWafBRTpPQCy UqJWNjJ6NMuulXg7OiOLqvR9+EF3byOM5xjSGyMW6iVGDjEOBmUPryDygZfmqM3hcPMlq/YFvVcSQZmdFUXe4/Kapr61ArPLiQThjJHNk9W3B11QqEwiqj/x CRGWLb+LkFgmjYOIhgb3HhwiQTmPJA2FCZIsY4IZrGXnp1QLUee2BZGmw0JNE78PXQTB187VTY8BmwMZtMUtklMYtdOsxN/jOEnIyaNGltPQciDrlxcA76kg w1xsBnjlegPmljrNd3vqRSroEayE6uryXJoi4O6PGQJV/LwScKPFQyc54q+a7W9LgBAZT0gd2AFWdE/IK6wfwa322KjHlB2iEBHGCedVdjo/LNx8ReWHM6OG NrPyB079A+TlwDD6SWMzjvAXsOIa42dBGqd+4agHrmbtRqXUcDyAhum8165mnwLDkFN9T7zLqZW4mF4dh/gfzZCm1sdGk9tbIa86qw== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Dexuan Cui If the daemon is NOT running at all, when we disable the util device from Hyper-V Manager (or sometimes the host can rescind a util device and then re-offer it), we'll hang in util_remove -> hv_kvp_deinit -> wait_for_completion(&release_event), because this code path doesn't run: hvt_op_release -> ... -> kvp_on_reset -> complete(&release_event). Due to this, we even can't reboot the VM properly. The patch tracks if the dev file is opened or not, and we only need to wait if it's opened. Fixes: 5a66fecbf6aa ("Drivers: hv: util: kvp: Fix a rescind processing issue") Signed-off-by: Dexuan Cui Cc: Vitaly Kuznetsov Cc: "K. Y. Srinivasan" Cc: Haiyang Zhang Cc: Stephen Hemminger Signed-off-by: K. Y. Srinivasan --- drivers/hv/hv_fcopy.c | 5 ++++- drivers/hv/hv_kvp.c | 6 +++++- drivers/hv/hv_snapshot.c | 5 ++++- drivers/hv/hv_utils_transport.c | 2 ++ drivers/hv/hv_utils_transport.h | 1 + 5 files changed, 16 insertions(+), 3 deletions(-) diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c index 9aee601..545cf43 100644 --- a/drivers/hv/hv_fcopy.c +++ b/drivers/hv/hv_fcopy.c @@ -358,8 +358,11 @@ int hv_fcopy_init(struct hv_util_service *srv) void hv_fcopy_deinit(void) { + bool wait = hvt->dev_opened; + fcopy_transaction.state = HVUTIL_DEVICE_DYING; cancel_delayed_work_sync(&fcopy_timeout_work); hvutil_transport_destroy(hvt); - wait_for_completion(&release_event); + if (wait) + wait_for_completion(&release_event); } diff --git a/drivers/hv/hv_kvp.c b/drivers/hv/hv_kvp.c index de26371..15c7873 100644 --- a/drivers/hv/hv_kvp.c +++ b/drivers/hv/hv_kvp.c @@ -742,10 +742,14 @@ static void kvp_on_reset(void) void hv_kvp_deinit(void) { + bool wait = hvt->dev_opened; + kvp_transaction.state = HVUTIL_DEVICE_DYING; cancel_delayed_work_sync(&kvp_host_handshake_work); cancel_delayed_work_sync(&kvp_timeout_work); cancel_work_sync(&kvp_sendkey_work); hvutil_transport_destroy(hvt); - wait_for_completion(&release_event); + + if (wait) + wait_for_completion(&release_event); } diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c index bcc03f0..3847f19 100644 --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -396,9 +396,12 @@ static void vss_on_reset(void) void hv_vss_deinit(void) { + bool wait = hvt->dev_opened; + vss_transaction.state = HVUTIL_DEVICE_DYING; cancel_delayed_work_sync(&vss_timeout_work); cancel_work_sync(&vss_handle_request_work); hvutil_transport_destroy(hvt); - wait_for_completion(&release_event); + if (wait) + wait_for_completion(&release_event); } diff --git a/drivers/hv/hv_utils_transport.c b/drivers/hv/hv_utils_transport.c index c235a95..05e0648 100644 --- a/drivers/hv/hv_utils_transport.c +++ b/drivers/hv/hv_utils_transport.c @@ -153,6 +153,7 @@ static int hvt_op_open(struct inode *inode, struct file *file) if (issue_reset) hvt_reset(hvt); + hvt->dev_opened = (hvt->mode == HVUTIL_TRANSPORT_CHARDEV) && !ret; mutex_unlock(&hvt->lock); @@ -182,6 +183,7 @@ static int hvt_op_release(struct inode *inode, struct file *file) * connects back. */ hvt_reset(hvt); + hvt->dev_opened = false; mutex_unlock(&hvt->lock); if (mode_old == HVUTIL_TRANSPORT_DESTROY) diff --git a/drivers/hv/hv_utils_transport.h b/drivers/hv/hv_utils_transport.h index d98f522..9871283 100644 --- a/drivers/hv/hv_utils_transport.h +++ b/drivers/hv/hv_utils_transport.h @@ -32,6 +32,7 @@ struct hvutil_transport { int mode; /* hvutil_transport_mode */ struct file_operations fops; /* file operations */ struct miscdevice mdev; /* misc device */ + bool dev_opened; /* Is the device opened? */ struct cb_id cn_id; /* CN_*_IDX/CN_*_VAL */ struct list_head list; /* hvt_list */ int (*on_msg)(void *, int); /* callback on new user message */ -- 1.7.1