[PATCH V3 1/2] vhost_net: correct error handling in vhost_net_set_backend()

Jason Wang
2013-01-06T07:18:37Z

Currently, when vhost_init_used() fails the sock refcnt and ubufs were
leaked. Correct this by calling vhost_init_used() before assign ubufs and
restore the oldsock when it fails.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
drivers/vhost/net.c | 16 +++++++++++-----
1 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index ebd08b2..d10ad6f 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -827,15 +827,16 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
r = PTR_ERR(ubufs);
goto err_ubufs;
}
- oldubufs = vq->ubufs;
- vq->ubufs = ubufs;
+
vhost_net_disable_vq(n, vq);
rcu_assign_pointer(vq->private_data, sock);
- vhost_net_enable_vq(n, vq);
-
r = vhost_init_used(vq);
if (r)
- goto err_vq;
+ goto err_used;
+ vhost_net_enable_vq(n, vq);
+
+ oldubufs = vq->ubufs;
+ vq->ubufs = ubufs;

n->tx_packets = 0;
n->tx_zcopy_err = 0;
@@ -859,6 +860,11 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd)
mutex_unlock(&n->dev.mutex);
return 0;

+err_used:
+ rcu_assign_pointer(vq->private_data, oldsock);
+ vhost_net_enable_vq(n, vq);
+ if (ubufs)
+ vhost_ubuf_put_and_wait(ubufs);
err_ubufs:
fput(sock->file);
err_vq:
--
1.7.1