On Mon, Aug 22, 2022 at 6:36 PM Jens Axboe <axboe@xxxxxxxxx> wrote:
> On 8/22/22 3:21 PM, Paul Moore wrote:
> > This patch adds support for the io_uring command pass through, aka
> > IORING_OP_URING_CMD, to the /dev/null driver. As with all of the
> > /dev/null functionality, the implementation is just a simple sink
> > where commands go to die, but it should be useful for developers who
> > need a simple IORING_OP_URING_CMD test device that doesn't require
> > any special hardware.
> >
> > Cc: Arnd Bergmann <arnd@xxxxxxxx>
> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Paul Moore <paul@xxxxxxxxxxxxxx>
> > ---
> > drivers/char/mem.c | 6 ++++++
> > 1 file changed, 6 insertions(+)
> >
> > diff --git a/drivers/char/mem.c b/drivers/char/mem.c
> > index 84ca98ed1dad..32a932a065a6 100644
> > --- a/drivers/char/mem.c
> > +++ b/drivers/char/mem.c
> > @@ -480,6 +480,11 @@ static ssize_t splice_write_null(struct pipe_inode_info *pipe, struct file *out,
> > return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null);
> > }
> >
> > +static int uring_cmd_null(struct io_uring_cmd *ioucmd, unsigned int issue_flags)
> > +{
> > + return 0;
> > +}
>
> This would be better as:
>
> return IOU_OK;
>
> using the proper return values for the uring_cmd hook.
The only problem I see with that is that IOU_OK is defined under
io_uring/io_uring.h and not include/linux/io_uring.h so the #include
macro is kinda ugly:
#include "../../io_uring/io_uring.h"
I'm not sure I want to submit that upstream looking like that. Are
you okay with leaving the return code as 0 for now and changing it at
a later date? I'm trying to keep this patchset relatively small since
we are in the -rcX stage, but if you're okay with a simple cut-n-paste
of the enum to linux/io_uring.h I can do that.
> With that:
>
> Acked-by: Jens Axboe <axboe@xxxxxxxxx>
--
paul-moore.com
