From 4d7b150822db4ea9e258d3ee99c3401f2e4f3952 Mon Sep 17 00:00:00 2001 From: Xiao Wang Date: Mon, 10 Aug 2015 05:09:22 +0200 Subject: [PATCH 01/16] vhost: correctly pass error to caller in vhost_dev_enable_notifiers() Message-id: <1439183375-4841-2-git-send-email-jasowang@redhat.com> Patchwork-id: 67428 O-Subject: [RHEL7.2 qemu-kvm-rhev PATCH 01/14] vhost: correctly pass error to caller in vhost_dev_enable_notifiers() Bugzilla: 1248312 RH-Acked-by: Vlad Yasevich RH-Acked-by: Paolo Bonzini RH-Acked-by: Michael S. Tsirkin We override the error value r in fail_vq, this will cause the caller can't detect the failure which may cause the caller may disable the notifiers twice if vhost is failed to start. Fix this by using another variable to keep track the return value of set_host_notifier(). Fixes b0b3db79559e57db340b292621c397e7a6cdbdc5 ("vhost-net: cleanup host notifiers at last step") Cc: qemu-stable@nongnu.org Cc: Michael S. Tsirkin Signed-off-by: Jason Wang Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit 16617e36b02ebdc83f215d89db9ac00f7d6d6d83) Signed-off-by: Miroslav Rezanina --- hw/virtio/vhost.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 9b492d4..0b311c8 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -969,7 +969,7 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); VirtioBusState *vbus = VIRTIO_BUS(qbus); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus); - int i, r; + int i, r, e; if (!k->set_host_notifier) { fprintf(stderr, "binding does not support host notifiers\n"); r = -ENOSYS; @@ -987,12 +987,12 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev) return 0; fail_vq: while (--i >= 0) { - r = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); - if (r < 0) { + e = k->set_host_notifier(qbus->parent, hdev->vq_index + i, false); + if (e < 0) { fprintf(stderr, "vhost VQ %d notifier cleanup error: %d\n", i, -r); fflush(stderr); } - assert (r >= 0); + assert (e >= 0); } fail: return r; -- 1.8.3.1