在 2021/7/13 下午9:27, Dan Carpenter 写道:
On Tue, Jul 13, 2021 at 04:46:55PM +0800, Xie Yongji wrote:+static int vduse_dev_init_vdpa(struct vduse_dev *dev, const char *name) +{ + struct vduse_vdpa *vdev; + int ret; + + if (dev->vdev) + return -EEXIST; + + vdev = vdpa_alloc_device(struct vduse_vdpa, vdpa, dev->dev, + &vduse_vdpa_config_ops, name, true); + if (!vdev) + return -ENOMEM;This should be an IS_ERR() check instead of a NULL check.
Yes.
The vdpa_alloc_device() macro is doing something very complicated but I'm not sure what. It calls container_of() and that looks buggy until you spot the BUILD_BUG_ON_ZERO() compile time assert which ensures that the container_of() is a no-op. Only one of the callers checks for error pointers correctly so maybe it's too complicated or maybe there should be better documentation.
We need better documentation for this macro and fix all the buggy callers. Yong Ji, want to do that? Thanks
regards, dan carpenter
