From 6da7225f5a95ba68e3c6225c4051182bef30eed4 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Fri, 13 May 2016 13:55:24 +0200 Subject: [PATCH] hv_netvsc: synchronize netvsc_change_mtu()/netvsc_set_channels() with netvsc_remove() When netvsc device is removed during mtu change or channels setup we get into troubles as both paths are trying to remove the device. Synchronize them with start_remove flag and rtnl lock. Signed-off-by: Vitaly Kuznetsov Signed-off-by: David S. Miller --- drivers/net/hyperv/netvsc_drv.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 7325d693fc4a..6a69b5cc9fe2 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -759,7 +759,7 @@ static int netvsc_set_channels(struct net_device *net, int ret = 0; bool recovering = false; - if (!nvdev || nvdev->destroy) + if (net_device_ctx->start_remove || !nvdev || nvdev->destroy) return -ENODEV; num_chn = nvdev->num_chn; @@ -907,7 +907,7 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu) u32 num_chn; int ret = 0; - if (nvdev == NULL || nvdev->destroy) + if (ndevctx->start_remove || !nvdev || nvdev->destroy) return -ENODEV; if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2) @@ -1445,7 +1445,12 @@ static int netvsc_remove(struct hv_device *dev) ndev_ctx = netdev_priv(net); net_device = ndev_ctx->nvdev; + /* Avoid racing with netvsc_change_mtu()/netvsc_set_channels() + * removing the device. + */ + rtnl_lock(); ndev_ctx->start_remove = true; + rtnl_unlock(); cancel_delayed_work_sync(&ndev_ctx->dwork); cancel_work_sync(&ndev_ctx->work);