tap: setting error appropriately when calling net_init_tap_one()

If netdev_add tap,id=net0,...,vhost=on failed in net_init_tap_one(),
the followed up device_add virtio-net-pci,netdev=net0 will fail
too, prints:

   TUNSETOFFLOAD ioctl() failed: Bad file descriptor TUNSETOFFLOAD
   ioctl() failed: Bad file descriptor

The reason is that the fd of tap is closed when error occured after
calling net_init_tap_one().

The fd should be closed when calling net_init_tap_one failed:
   - if tap_set_sndbuf() failed
   - if tap_set_sndbuf() succeeded but vhost failed to open or
     initialize with vhostforce flag on
   - with wrong vhost command line parameter
The fd should not be closed just because vhost failed to open or
initialize but without vhostforce flag. So the followed up
device_add can fall back to userspace virtio successfully.

Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Suggested-by: Igor Mammedov <imammedo@redhat.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jay Zhou <jianjay.zhou@huawei.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
stable-2.12
Jay Zhou 2018-03-02 17:04:44 +08:00 committed by Jason Wang
parent b20219b645
commit 46d4d36d0b
2 changed files with 20 additions and 5 deletions

View File

@ -4,6 +4,9 @@
#include "net/net.h"
#include "hw/virtio/vhost-backend.h"
#define VHOST_NET_INIT_FAILED \
"vhost-net requested but could not be initialized"
struct vhost_net;
typedef struct vhost_net VHostNetState;

View File

@ -686,14 +686,23 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
if (vhostfdname) {
vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
if (vhostfd == -1) {
error_propagate(errp, err);
if (tap->has_vhostforce && tap->vhostforce) {
error_propagate(errp, err);
} else {
warn_report_err(err);
}
return;
}
} else {
vhostfd = open("/dev/vhost-net", O_RDWR);
if (vhostfd < 0) {
error_setg_errno(errp, errno,
"tap: open vhost char device failed");
if (tap->has_vhostforce && tap->vhostforce) {
error_setg_errno(errp, errno,
"tap: open vhost char device failed");
} else {
warn_report("tap: open vhost char device failed: %s",
strerror(errno));
}
return;
}
fcntl(vhostfd, F_SETFL, O_NONBLOCK);
@ -702,8 +711,11 @@ static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
s->vhost_net = vhost_net_init(&options);
if (!s->vhost_net) {
error_setg(errp,
"vhost-net requested but could not be initialized");
if (tap->has_vhostforce && tap->vhostforce) {
error_setg(errp, VHOST_NET_INIT_FAILED);
} else {
warn_report(VHOST_NET_INIT_FAILED);
}
return;
}
} else if (vhostfdname) {