Yes in 5.8 branch would be the easiest...
You rock!
Bye
Norman
> Am 05.09.2020 um 19:11 schrieb Jens Axboe <axboe@xxxxxxxxx>:
>
> On 9/5/20 11:03 AM, Norman Maurer wrote:
>> Hi there,
>>
>> As you may have noticed from previous emails we are currently writing
>> a new transport for netty that will use io_uring under the hood for
>> max performance. One thing that is missing at the moment is the
>> support for “shutdown”. Shutdown is quite useful in TCP land when you
>> only want to close either input or output of the connection.
>>
>> Is this something you think that can be added in the future ? This
>> would be a perfect addition to the already existing close support.
>
> Something like this should do it, should just be split into having the
> net part as a prep patch. I can add this to the 5.8 branch if that's
> easier for you to test?
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index a9a625ceea5f..67714078e85d 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -529,6 +529,11 @@ struct io_statx {
> struct statx __user *buffer;
> };
>
> +struct io_shutdown {
> + struct file *file;
> + int how;
> +};
> +
> struct io_completion {
> struct file *file;
> struct list_head list;
> @@ -666,6 +671,7 @@ struct io_kiocb {
> struct io_splice splice;
> struct io_provide_buf pbuf;
> struct io_statx statx;
> + struct io_shutdown shutdown;
> /* use only after cleaning per-op data, see io_clean_op() */
> struct io_completion compl;
> };
> @@ -922,6 +928,9 @@ static const struct io_op_def io_op_defs[] __read_mostly = {
> .hash_reg_file = 1,
> .unbound_nonreg_file = 1,
> },
> + [IORING_OP_SHUTDOWN] = {
> + .needs_file = 1,
> + },
> };
>
> enum io_mem_account {
> @@ -3367,6 +3376,44 @@ static int io_write(struct io_kiocb *req, bool force_nonblock,
> return ret;
> }
>
> +static int io_shutdown_prep(struct io_kiocb *req,
> + const struct io_uring_sqe *sqe)
> +{
> +#if defined(CONFIG_NET)
> + if (unlikely(req->ctx->flags & (IORING_SETUP_IOPOLL|IORING_SETUP_SQPOLL)))
> + return -EINVAL;
> + if (sqe->ioprio || sqe->off || sqe->addr || sqe->len ||
> + sqe->rw_flags || sqe->buf_index)
> + return -EINVAL;
> +
> + req->shutdown.how = READ_ONCE(sqe->len);
> + return 0;
> +#else
> + return -EOPNOTSUPP;
> +#endif
> +}
> +
> +static int io_shutdown(struct io_kiocb *req, bool force_nonblock)
> +{
> +#if defined(CONFIG_NET)
> + struct socket *sock;
> + int ret;
> +
> + if (force_nonblock)
> + return -EAGAIN;
> +
> + sock = sock_from_file(req->file, &ret);
> + if (unlikely(!sock))
> + return ret;
> +
> + ret = __sys_shutdown_sock(sock, req->shutdown.how);
> + io_req_complete(req, ret);
> + return 0;
> +#else
> + return -EOPNOTSUPP;
> +#endif
> +}
> +
> static int __io_splice_prep(struct io_kiocb *req,
> const struct io_uring_sqe *sqe)
> {
> @@ -5588,6 +5635,9 @@ static int io_req_defer_prep(struct io_kiocb *req,
> case IORING_OP_TEE:
> ret = io_tee_prep(req, sqe);
> break;
> + case IORING_OP_SHUTDOWN:
> + ret = io_shutdown_prep(req, sqe);
> + break;
> default:
> printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
> req->opcode);
> @@ -5942,6 +5992,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
> }
> ret = io_tee(req, force_nonblock);
> break;
> + case IORING_OP_SHUTDOWN:
> + if (req) {
> + ret = io_shutdown_prep(req, sqe);
> + if (ret < 0)
> + break;
> + }
> + ret = io_shutdown(req, force_nonblock);
> + break;
> default:
> ret = -EINVAL;
> break;
> diff --git a/include/linux/socket.h b/include/linux/socket.h
> index e9cb30d8cbfb..385894b4a8bb 100644
> --- a/include/linux/socket.h
> +++ b/include/linux/socket.h
> @@ -436,6 +436,7 @@ extern int __sys_getpeername(int fd, struct sockaddr __user *usockaddr,
> int __user *usockaddr_len);
> extern int __sys_socketpair(int family, int type, int protocol,
> int __user *usockvec);
> +extern int __sys_shutdown_sock(struct socket *sock, int how);
> extern int __sys_shutdown(int fd, int how);
>
> extern struct ns_common *get_net_ns(struct ns_common *ns);
> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index 7539d912690b..2301c37e86cb 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -132,6 +132,7 @@ enum {
> IORING_OP_PROVIDE_BUFFERS,
> IORING_OP_REMOVE_BUFFERS,
> IORING_OP_TEE,
> + IORING_OP_SHUTDOWN,
>
> /* this goes last, obviously */
> IORING_OP_LAST,
> diff --git a/net/socket.c b/net/socket.c
> index 0c0144604f81..8616962c27bc 100644
> --- a/net/socket.c
> +++ b/net/socket.c
> @@ -2192,6 +2192,17 @@ SYSCALL_DEFINE5(getsockopt, int, fd, int, level, int, optname,
> * Shutdown a socket.
> */
>
> +int __sys_shutdown_sock(struct socket *sock, int how)
> +{
> + int err;
> +
> + err = security_socket_shutdown(sock, how);
> + if (!err)
> + err = sock->ops->shutdown(sock, how);
> +
> + return err;
> +}
> +
> int __sys_shutdown(int fd, int how)
> {
> int err, fput_needed;
> @@ -2199,9 +2210,7 @@ int __sys_shutdown(int fd, int how)
>
> sock = sockfd_lookup_light(fd, &err, &fput_needed);
> if (sock != NULL) {
> - err = security_socket_shutdown(sock, how);
> - if (!err)
> - err = sock->ops->shutdown(sock, how);
> + err = __sys_shutdown_sock(sock, how);
> fput_light(sock->file, fput_needed);
> }
> return err;
>
> --
> Jens Axboe
>
