io_uring: warn about unhandled opcode

Now that we have all the opcodes handled in terms of command prep and
SQE reuse, add a printk_once() to warn about any potentially new and
unhandled ones.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index e0fc195..1d4e733 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3079,9 +3079,11 @@ static int io_req_defer_prep(struct io_kiocb *req)
        struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs;
        struct io_async_ctx *io = req->io;
        struct iov_iter iter;
-       ssize_t ret;
+       ssize_t ret = 0;
 
        switch (req->opcode) {
+       case IORING_OP_NOP:
+               break;
        case IORING_OP_READV:
        case IORING_OP_READ_FIXED:
                /* ensure prep does right import */
@@ -3141,7 +3143,9 @@ static int io_req_defer_prep(struct io_kiocb *req)
                ret = io_accept_prep(req);
                break;
        default:
-               ret = 0;
+               printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
+                               req->opcode);
+               ret = -EINVAL;
                break;
        }