Re: [PATCH 1/3] io_uring: add io_uring_get_opcode

[Jens Axboe <axboe@kernel.dk>]

On 4/25/22 3:36 AM, Dylan Yudaken wrote:
> In some debug scenarios it is useful to have the text representation of
> the opcode. Add this function in preparation.
> 
> Signed-off-by: Dylan Yudaken <dylany@fb.com>
> ---
>  fs/io_uring.c            | 91 ++++++++++++++++++++++++++++++++++++++++
>  include/linux/io_uring.h |  5 +++
>  2 files changed, 96 insertions(+)
> 
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index e57d47a23682..326695f74b93 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -1255,6 +1255,97 @@ static struct kmem_cache *req_cachep;
>  
>  static const struct file_operations io_uring_fops;
>  
> +const char *io_uring_get_opcode(u8 opcode)
> +{
> +	switch (opcode) {
> +	case IORING_OP_NOP:
> +		return "NOP";
> +	case IORING_OP_READV:
> +		return "READV";
> +	case IORING_OP_WRITEV:
> +		return "WRITEV";
> +	case IORING_OP_FSYNC:
> +		return "FSYNC";
> +	case IORING_OP_READ_FIXED:
> +		return "READ_FIXED";
> +	case IORING_OP_WRITE_FIXED:
> +		return "WRITE_FIXED";
> +	case IORING_OP_POLL_ADD:
> +		return "POLL_ADD";
> +	case IORING_OP_POLL_REMOVE:
> +		return "POLL_REMOVE";
> +	case IORING_OP_SYNC_FILE_RANGE:
> +		return "SYNC_FILE_RANGE";
> +	case IORING_OP_SENDMSG:
> +		return "SENDMSG";
> +	case IORING_OP_RECVMSG:
> +		return "RECVMSG";
> +	case IORING_OP_TIMEOUT:
> +		return "TIMEOUT";
> +	case IORING_OP_TIMEOUT_REMOVE:
> +		return "TIMEOUT_REMOVE";
> +	case IORING_OP_ACCEPT:
> +		return "ACCEPT";
> +	case IORING_OP_ASYNC_CANCEL:
> +		return "ASYNC_CANCEL";
> +	case IORING_OP_LINK_TIMEOUT:
> +		return "LINK_TIMEOUT";
> +	case IORING_OP_CONNECT:
> +		return "CONNECT";
> +	case IORING_OP_FALLOCATE:
> +		return "FALLOCATE";
> +	case IORING_OP_OPENAT:
> +		return "OPENAT";
> +	case IORING_OP_CLOSE:
> +		return "CLOSE";
> +	case IORING_OP_FILES_UPDATE:
> +		return "FILES_UPDATE";
> +	case IORING_OP_STATX:
> +		return "STATX";
> +	case IORING_OP_READ:
> +		return "READ";
> +	case IORING_OP_WRITE:
> +		return "WRITE";
> +	case IORING_OP_FADVISE:
> +		return "FADVISE";
> +	case IORING_OP_MADVISE:
> +		return "MADVISE";
> +	case IORING_OP_SEND:
> +		return "SEND";
> +	case IORING_OP_RECV:
> +		return "RECV";
> +	case IORING_OP_OPENAT2:
> +		return "OPENAT2";
> +	case IORING_OP_EPOLL_CTL:
> +		return "EPOLL_CTL";
> +	case IORING_OP_SPLICE:
> +		return "SPLICE";
> +	case IORING_OP_PROVIDE_BUFFERS:
> +		return "PROVIDE_BUFFERS";
> +	case IORING_OP_REMOVE_BUFFERS:
> +		return "REMOVE_BUFFERS";
> +	case IORING_OP_TEE:
> +		return "TEE";
> +	case IORING_OP_SHUTDOWN:
> +		return "SHUTDOWN";
> +	case IORING_OP_RENAMEAT:
> +		return "RENAMEAT";
> +	case IORING_OP_UNLINKAT:
> +		return "UNLINKAT";
> +	case IORING_OP_MKDIRAT:
> +		return "MKDIRAT";
> +	case IORING_OP_SYMLINKAT:
> +		return "SYMLINKAT";
> +	case IORING_OP_LINKAT:
> +		return "LINKAT";
> +	case IORING_OP_MSG_RING:
> +		return "MSG_RING";
> +	case IORING_OP_LAST:
> +		return "LAST";
> +	}
> +	return "UNKNOWN";
> +}

My only worry here is that it's another place to touch when adding an
opcode. I'm assuming the compiler doesn't warn if you're missing one
since it's not strongly typed?

In any case, the LAST one is just a sentinel, both that and beyond
should return eg INVALID.

-- 
Jens Axboe