In vhost_vdpa ioctl SET_BACKEND_FEATURES path, currect code
would try to acquire vhost dev mutex twice
(first shown in vhost_vdpa_unlocked_ioctl), which can lead
to a dead lock issue.
This commit removed mutex operations in vhost_set_backend_features.
As a compensation for vhost_net, a followinig commit will add
needed mutex lock/unlock operations in a new function
vhost_net_set_backend_features() which is a wrap of
vhost_set_backend_features().
Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
---
drivers/vhost/vhost.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index b45519ca66a7..e03c9e6f058f 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -2591,14 +2591,12 @@ void vhost_set_backend_features(struct vhost_dev *dev, u64 features)
struct vhost_virtqueue *vq;
int i;
- mutex_lock(&dev->mutex);
for (i = 0; i < dev->nvqs; ++i) {
vq = dev->vqs[i];
mutex_lock(&vq->mutex);
vq->acked_backend_features = features;
mutex_unlock(&vq->mutex);
}
- mutex_unlock(&dev->mutex);
}
EXPORT_SYMBOL_GPL(vhost_set_backend_features);
--
2.18.4
