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

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;

}