On Tue, Aug 23, 2022 at 2:52 AM Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Mon, Aug 22, 2022 at 05:21:19PM -0400, 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. > > Also, shouldn't you document this somewhere? > > At least in the code itself saying "this is here so that /dev/null works > as a io_uring sink" or something like that? Otherwise it just looks > like it does nothing at all. What about read_null() and write_null()? I can definitely add a comment (there is no /dev/null documentation in the kernel source tree that I can see), but there is clearly precedence for /dev/null having "do nothing" file_operations functions. If nothing else, it's pretty much in the *name*; we're adding the "uring_cmd_null()" member function to the "null_fops" struct for the "null" device ... come on Greg :) -- paul-moore.com
