vhost: check owner before we overwrite ubuf_info

If device has an owner, we shouldn't touch ubuf_info
since it might be in use.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Michael S. Tsirkin 2013-06-06 15:20:39 +03:00 committed by David S. Miller
parent c2020be3c3
commit 05c0535194
3 changed files with 12 additions and 1 deletions

View File

@ -1054,6 +1054,10 @@ static long vhost_net_set_owner(struct vhost_net *n)
int r;
mutex_lock(&n->dev.mutex);
if (vhost_dev_has_owner(&n->dev)) {
r = -EBUSY;
goto out;
}
r = vhost_net_set_ubuf_info(n);
if (r)
goto out;

View File

@ -343,6 +343,12 @@ static int vhost_attach_cgroups(struct vhost_dev *dev)
return attach.ret;
}
/* Caller should have device mutex */
bool vhost_dev_has_owner(struct vhost_dev *dev)
{
return dev->mm;
}
/* Caller should have device mutex */
long vhost_dev_set_owner(struct vhost_dev *dev)
{
@ -350,7 +356,7 @@ long vhost_dev_set_owner(struct vhost_dev *dev)
int err;
/* Is there an owner already? */
if (dev->mm) {
if (vhost_dev_has_owner(dev)) {
err = -EBUSY;
goto err_mm;
}

View File

@ -133,6 +133,7 @@ struct vhost_dev {
long vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs);
long vhost_dev_set_owner(struct vhost_dev *dev);
bool vhost_dev_has_owner(struct vhost_dev *dev);
long vhost_dev_check_owner(struct vhost_dev *);
struct vhost_memory *vhost_dev_reset_owner_prepare(void);
void vhost_dev_reset_owner(struct vhost_dev *, struct vhost_memory *);