vfio: Fold VFIO_GROUP_SET_CONTAINER into vfio_group_set_container()

No reason to split it up like this, just have one function to process the
ioctl. Move the lock into the function as well to avoid having a lockdep
annotation.

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/6-v2-0f9e632d54fb+d6-vfio_ioctl_split_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c
index 3afef45..17c44ee 100644 (file)
--- a/drivers/vfio/vfio_main.c
+++ b/drivers/vfio/vfio_main.c
@@ -980,47 +980,54 @@ static int vfio_group_unset_container(struct vfio_group *group)
        return 0;
 }
 
-static int vfio_group_set_container(struct vfio_group *group, int container_fd)
+static int vfio_group_ioctl_set_container(struct vfio_group *group,
+                                         int __user *arg)
 {
        struct fd f;
        struct vfio_container *container;
        struct vfio_iommu_driver *driver;
+       int container_fd;
        int ret = 0;
 
-       lockdep_assert_held_write(&group->group_rwsem);
-
-       if (group->container || WARN_ON(group->container_users))
-               return -EINVAL;
-
        if (group->type == VFIO_NO_IOMMU && !capable(CAP_SYS_RAWIO))
                return -EPERM;
 
+       if (get_user(container_fd, arg))
+               return -EFAULT;
+       if (container_fd < 0)
+               return -EINVAL;
        f = fdget(container_fd);
        if (!f.file)
                return -EBADF;
 
        /* Sanity check, is this really our fd? */
        if (f.file->f_op != &vfio_fops) {
-               fdput(f);
-               return -EINVAL;
+               ret = -EINVAL;
+               goto out_fdput;
        }
-
        container = f.file->private_data;
        WARN_ON(!container); /* fget ensures we don't race vfio_release */
 
+       down_write(&group->group_rwsem);
+
+       if (group->container || WARN_ON(group->container_users)) {
+               ret = -EINVAL;
+               goto out_unlock_group;
+       }
+
        down_write(&container->group_lock);
 
        /* Real groups and fake groups cannot mix */
        if (!list_empty(&container->group_list) &&
            container->noiommu != (group->type == VFIO_NO_IOMMU)) {
                ret = -EPERM;
-               goto unlock_out;
+               goto out_unlock_container;
        }
 
        if (group->type == VFIO_IOMMU) {
                ret = iommu_group_claim_dma_owner(group->iommu_group, f.file);
                if (ret)
-                       goto unlock_out;
+                       goto out_unlock_container;
        }
 
        driver = container->iommu_driver;
@@ -1032,7 +1039,7 @@ static int vfio_group_set_container(struct vfio_group *group, int container_fd)
                        if (group->type == VFIO_IOMMU)
                                iommu_group_release_dma_owner(
                                        group->iommu_group);
-                       goto unlock_out;
+                       goto out_unlock_container;
                }
        }
 
@@ -1044,8 +1051,11 @@ static int vfio_group_set_container(struct vfio_group *group, int container_fd)
        /* Get a reference on the container and mark a user within the group */
        vfio_container_get(container);
 
-unlock_out:
+out_unlock_container:
        up_write(&container->group_lock);
+out_unlock_group:
+       up_write(&group->group_rwsem);
+out_fdput:
        fdput(f);
        return ret;
 }
@@ -1258,20 +1268,7 @@ static long vfio_group_fops_unl_ioctl(struct file *filep,
                break;
        }
        case VFIO_GROUP_SET_CONTAINER:
-       {
-               int fd;
-
-               if (get_user(fd, (int __user *)arg))
-                       return -EFAULT;
-
-               if (fd < 0)
-                       return -EINVAL;
-
-               down_write(&group->group_rwsem);
-               ret = vfio_group_set_container(group, fd);
-               up_write(&group->group_rwsem);
-               break;
-       }
+               return vfio_group_ioctl_set_container(group, uarg);
        case VFIO_GROUP_UNSET_CONTAINER:
                down_write(&group->group_rwsem);
                ret = vfio_group_unset_container(group);