Re: [PATCH 08/12] vfio: use __anon_inode_getfd

Alex Williamson
2020-05-08T15:55:17Z

On Fri, 8 May 2020 17:36:30 +0200
Christoph Hellwig <hch@lst.de> wrote:

> Use __anon_inode_getfd instead of opencoding the logic using
> get_unused_fd_flags + anon_inode_getfile.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
> drivers/vfio/vfio.c | 37 ++++++++-----------------------------
> 1 file changed, 8 insertions(+), 29 deletions(-)

Thanks!

Acked-by: Alex Williamson <alex.williamson@redhat.com>

> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
> index 765e0e5d83ed9..33a88103f857f 100644
> --- a/drivers/vfio/vfio.c
> +++ b/drivers/vfio/vfio.c
> @@ -1451,42 +1451,21 @@ static int vfio_group_get_device_fd(struct vfio_group *group, char *buf)
> return ret;
> }
>
> - /*
> - * We can't use anon_inode_getfd() because we need to modify
> - * the f_mode flags directly to allow more than just ioctls
> - */
> - ret = get_unused_fd_flags(O_CLOEXEC);
> - if (ret < 0) {
> - device->ops->release(device->device_data);
> - vfio_device_put(device);
> - return ret;
> - }
> -
> - filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,
> - device, O_RDWR);
> - if (IS_ERR(filep)) {
> - put_unused_fd(ret);
> - ret = PTR_ERR(filep);
> - device->ops->release(device->device_data);
> - vfio_device_put(device);
> - return ret;
> - }
> -
> - /*
> - * TODO: add an anon_inode interface to do this.
> - * Appears to be missing by lack of need rather than
> - * explicitly prevented. Now there's need.
> - */
> + ret = __anon_inode_getfd("[vfio-device]", &vfio_device_fops,
> + device, O_CLOEXEC | O_RDWR, &filep);
> + if (ret < 0)
> + goto release;
> filep->f_mode |= (FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
> -
> atomic_inc(&group->container_users);
> -
> fd_install(ret, filep);
>
> if (group->noiommu)
> dev_warn(device->dev, "vfio-noiommu device opened by user "
> "(%s:%d)\n", current->comm, task_pid_nr(current));
> -
> + return ret;
> +release:
> + device->ops->release(device->device_data);
> + vfio_device_put(device);
> return ret;
> }
>