io_uring: add support for shutdown(2)

This adds support for the shutdown(2) system call, which is useful for
dealing with sockets.

shutdown(2) may block, so we have to punt it to async context.

Suggested-by: Norman Maurer <norman.maurer@googlemail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 3cc1e59..d171987 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -541,6 +541,11 @@ 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;
@@ -667,6 +672,7 @@ 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;
        };
@@ -934,6 +940,9 @@ static const struct io_op_def io_op_defs[] = {
                .hash_reg_file          = 1,
                .unbound_nonreg_file    = 1,
        },
+       [IORING_OP_SHUTDOWN] = {
+               .needs_file             = 1,
+       },
 };
 
 enum io_mem_account {
@@ -3591,6 +3600,44 @@ out_free:
        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))
+               return -EINVAL;
+       if (sqe->ioprio || sqe->off || sqe->addr || 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)
 {
@@ -5775,6 +5822,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
                return io_remove_buffers_prep(req, sqe);
        case IORING_OP_TEE:
                return io_tee_prep(req, sqe);
+       case IORING_OP_SHUTDOWN:
+               return io_shutdown_prep(req, sqe);
        }
 
        printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
@@ -6018,6 +6067,9 @@ static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
        case IORING_OP_TEE:
                ret = io_tee(req, force_nonblock);
                break;
+       case IORING_OP_SHUTDOWN:
+               ret = io_shutdown(req, force_nonblock);
+               break;
        default:
                ret = -EINVAL;
                break;

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 98d8e06..e943bf0 100644 (file)
--- 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,