On Thu, Feb 17, 2022 at 10:29:21AM +0800, Guixin Liu wrote: > In TCMU, if backstore holds its own userspace buffer, for read cmd, the > data needs to be copied from userspace buffer to tcmu data area first, > and then needs to be copied from tcmu data area to scsi sgl pages again. > > To solve this problem, add ioctl to uio to let userspace backstore can > copy data between scsi sgl pages and its own buffer directly. > > Reviewed-by: Xiaoguang Wang <xiaoguang.wang@xxxxxxxxxxxxxxxxx> > Signed-off-by: Guixin Liu <kanie@xxxxxxxxxxxxxxxxx> > --- > drivers/uio/uio.c | 22 ++++++++++++++++++++++ > include/linux/uio_driver.h | 1 + No, sorry, thie uio driver will not be adding ioctls to them. If you need an ioctl, then you should not be using the UIO api but rather use a custom character driver instead. thanks, greg k-h