From: Stephen Hemminger <stephen@networkplumber•org>
To: kys@microsoft•com, haiyangz@microsoft•com, sthemmin@microsoft•com
Cc: devel@linuxdriverproject•org, netdev@vger•kernel.org
Subject: [PATCH net-next 1/1] netvsc: fix rtnl deadlock on unregister of vf
Date: Fri, 4 Aug 2017 12:14:00 -0700 [thread overview]
Message-ID: <20170804191400.22471-2-sthemmin@microsoft.com> (raw)
In-Reply-To: <20170804191400.22471-1-sthemmin@microsoft.com>
With new transparent VF support, it is possible to get a deadlock
when some of the deferred work is running and the unregister_vf
is trying to cancel the work element. The solution is to use
trylock and reschedule (similar to bonding and team device).
Reported-by: Vitaly Kuznetsov <vkuznets@redhat•com>
Fixes: 0c195567a8f6 ("netvsc: transparent VF management")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft•com>
---
drivers/net/hyperv/netvsc_drv.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index c71728d82049..e75c0f852a63 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1601,7 +1601,11 @@ static void netvsc_vf_setup(struct work_struct *w)
struct net_device *ndev = hv_get_drvdata(ndev_ctx->device_ctx);
struct net_device *vf_netdev;
- rtnl_lock();
+ if (!rtnl_trylock()) {
+ schedule_work(w);
+ return;
+ }
+
vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
if (vf_netdev)
__netvsc_vf_setup(ndev, vf_netdev);
@@ -1655,7 +1659,11 @@ static void netvsc_vf_update(struct work_struct *w)
struct net_device *vf_netdev;
bool vf_is_up;
- rtnl_lock();
+ if (!rtnl_trylock()) {
+ schedule_work(w);
+ return;
+ }
+
vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
if (!vf_netdev)
goto unlock;
--
2.11.0
next prev parent reply other threads:[~2017-08-04 19:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-04 19:13 [PATCH net-next 0/1] netvsc: fix deadlock in VF unregister Stephen Hemminger
2017-08-04 19:14 ` Stephen Hemminger [this message]
2017-08-07 4:29 ` [PATCH net-next 1/1] netvsc: fix rtnl deadlock on unregister of vf David Miller
2017-08-07 13:08 ` Vitaly Kuznetsov
2017-08-07 13:37 ` Vitaly Kuznetsov
2017-08-07 15:17 ` Vitaly Kuznetsov
2017-08-07 15:21 ` Stephen Hemminger
2017-08-07 15:17 ` Stephen Hemminger
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