Hello. On 05-06-2013 11:40, Jason Wang wrote:
When we decide not use zero-copy, msg.control should be set to NULL otherwise macvtap/tap may set zerocopy callbacks which may decrease the kref of ubufs wrongly.
Bug were introduced by commit cedb9bdce099206290a2bdd02ce47a7b253b6a84 (vhost-net: skip head management if no outstanding).
This solves the following warnings:
WARNING: at include/linux/kref.h:47 handle_tx+0x477/0x4b0 [vhost_net]() Modules linked in: vhost_net macvtap macvlan tun nfsd exportfs bridge stp llc openvswitch kvm_amd kvm bnx2 megaraid_sas [last unloaded: tun] CPU: 5 PID: 8670 Comm: vhost-8668 Not tainted 3.10.0-rc2+ #1566 Hardware name: Dell Inc. PowerEdge R715/00XHKG, BIOS 1.5.2 04/19/2011 ffffffffa0198323 ffff88007c9ebd08 ffffffff81796b73 ffff88007c9ebd48 ffffffff8103d66b 000000007b773e20 ffff8800779f0000 ffff8800779f43f0 ffff8800779f8418 000000000000015c 0000000000000062 ffff88007c9ebd58 Call Trace: [<ffffffff81796b73>] dump_stack+0x19/0x1e [<ffffffff8103d66b>] warn_slowpath_common+0x6b/0xa0 [<ffffffff8103d6b5>] warn_slowpath_null+0x15/0x20 [<ffffffffa0197627>] handle_tx+0x477/0x4b0 [vhost_net] [<ffffffffa0197690>] handle_tx_kick+0x10/0x20 [vhost_net] [<ffffffffa019541e>] vhost_worker+0xfe/0x1a0 [vhost_net] [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net] [<ffffffffa0195320>] ? vhost_attach_cgroups_work+0x30/0x30 [vhost_net] [<ffffffff81061f46>] kthread+0xc6/0xd0 [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70 [<ffffffff817a1aec>] ret_from_fork+0x7c/0xb0 [<ffffffff81061e80>] ? kthread_freezable_should_stop+0x70/0x70
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> --- drivers/vhost/net.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 2b51e23..b07d96b 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -436,7 +436,8 @@ static void handle_tx(struct vhost_net *net) kref_get(&ubufs->kref); } nvq->upend_idx = (nvq->upend_idx + 1) % UIO_MAXIOV; - } + } else
You have to use {} on the *else* branch if you have it of the *if* branch (and vice versa), according to Documentation/CodingStyle.
+ msg.msg_control = NULL;
WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
