io_uring: add tee(2) support

Add IORING_OP_TEE implementing tee(2) support. Almost identical to
splice bits, but without offsets.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index c433403..026350b 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -853,6 +853,11 @@ static const struct io_op_def io_op_defs[] = {
        },
        [IORING_OP_PROVIDE_BUFFERS] = {},
        [IORING_OP_REMOVE_BUFFERS] = {},
+       [IORING_OP_TEE] = {
+               .needs_file             = 1,
+               .hash_reg_file          = 1,
+               .unbound_nonreg_file    = 1,
+       },
 };
 
 static void io_wq_submit_work(struct io_wq_work **workptr);
@@ -2748,7 +2753,8 @@ out_free:
        return ret;
 }
 
-static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+static int __io_splice_prep(struct io_kiocb *req,
+                           const struct io_uring_sqe *sqe)
 {
        struct io_splice* sp = &req->splice;
        unsigned int valid_flags = SPLICE_F_FD_IN_FIXED | SPLICE_F_ALL;
@@ -2758,8 +2764,6 @@ static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
                return 0;
 
        sp->file_in = NULL;
-       sp->off_in = READ_ONCE(sqe->splice_off_in);
-       sp->off_out = READ_ONCE(sqe->off);
        sp->len = READ_ONCE(sqe->len);
        sp->flags = READ_ONCE(sqe->splice_flags);
 
@@ -2778,6 +2782,46 @@ static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        return 0;
 }
 
+static int io_tee_prep(struct io_kiocb *req,
+                      const struct io_uring_sqe *sqe)
+{
+       if (READ_ONCE(sqe->splice_off_in) || READ_ONCE(sqe->off))
+               return -EINVAL;
+       return __io_splice_prep(req, sqe);
+}
+
+static int io_tee(struct io_kiocb *req, bool force_nonblock)
+{
+       struct io_splice *sp = &req->splice;
+       struct file *in = sp->file_in;
+       struct file *out = sp->file_out;
+       unsigned int flags = sp->flags & ~SPLICE_F_FD_IN_FIXED;
+       long ret = 0;
+
+       if (force_nonblock)
+               return -EAGAIN;
+       if (sp->len)
+               ret = do_tee(in, out, sp->len, flags);
+
+       io_put_file(req, in, (sp->flags & SPLICE_F_FD_IN_FIXED));
+       req->flags &= ~REQ_F_NEED_CLEANUP;
+
+       io_cqring_add_event(req, ret);
+       if (ret != sp->len)
+               req_set_fail_links(req);
+       io_put_req(req);
+       return 0;
+}
+
+static int io_splice_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+       struct io_splice* sp = &req->splice;
+
+       sp->off_in = READ_ONCE(sqe->splice_off_in);
+       sp->off_out = READ_ONCE(sqe->off);
+       return __io_splice_prep(req, sqe);
+}
+
 static int io_splice(struct io_kiocb *req, bool force_nonblock)
 {
        struct io_splice *sp = &req->splice;
@@ -5085,6 +5129,9 @@ static int io_req_defer_prep(struct io_kiocb *req,
        case IORING_OP_REMOVE_BUFFERS:
                ret = io_remove_buffers_prep(req, sqe);
                break;
+       case IORING_OP_TEE:
+               ret = io_tee_prep(req, sqe);
+               break;
        default:
                printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
                                req->opcode);
@@ -5158,6 +5205,7 @@ static void io_cleanup_req(struct io_kiocb *req)
                putname(req->open.filename);
                break;
        case IORING_OP_SPLICE:
+       case IORING_OP_TEE:
                io_put_file(req, req->splice.file_in,
                            (req->splice.flags & SPLICE_F_FD_IN_FIXED));
                break;
@@ -5388,6 +5436,14 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
                }
                ret = io_remove_buffers(req, force_nonblock);
                break;
+       case IORING_OP_TEE:
+               if (sqe) {
+                       ret = io_tee_prep(req, sqe);
+                       if (ret < 0)
+                               break;
+               }
+               ret = io_tee(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 8c5775d..92c2269 100644 (file)
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -129,6 +129,7 @@ enum {
        IORING_OP_SPLICE,
        IORING_OP_PROVIDE_BUFFERS,
        IORING_OP_REMOVE_BUFFERS,
+       IORING_OP_TEE,
 
        /* this goes last, obviously */
        IORING_OP_LAST,