io_uring/net: send retry for zerocopy

io_uring handles short sends/recvs for stream sockets when MSG_WAITALL
is set, however new zerocopy send is inconsistent in this regard, which
might be confusing. Handle short sends.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b876a4838597d9bba4f3215db60d72c33c448ad0.1659622472.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/io_uring/net.c b/io_uring/net.c
index 32fc3da..f9f080b 100644 (file)
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -70,6 +70,7 @@ struct io_sendzc {
        unsigned                        flags;
        unsigned                        addr_len;
        void __user                     *addr;
+       size_t                          done_io;
 };
 
 #define IO_APOLL_MULTI_POLLED (REQ_F_APOLL_MULTISHOT | REQ_F_POLLED)
@@ -878,6 +879,7 @@ int io_sendzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 
        zc->addr = u64_to_user_ptr(READ_ONCE(sqe->addr2));
        zc->addr_len = READ_ONCE(sqe->addr_len);
+       zc->done_io = 0;
 
 #ifdef CONFIG_COMPAT
        if (req->ctx->compat)
@@ -1012,11 +1014,23 @@ int io_sendzc(struct io_kiocb *req, unsigned int issue_flags)
        if (unlikely(ret < min_ret)) {
                if (ret == -EAGAIN && (issue_flags & IO_URING_F_NONBLOCK))
                        return -EAGAIN;
-               return ret == -ERESTARTSYS ? -EINTR : ret;
+               if (ret > 0 && io_net_retry(sock, msg.msg_flags)) {
+                       zc->len -= ret;
+                       zc->buf += ret;
+                       zc->done_io += ret;
+                       req->flags |= REQ_F_PARTIAL_IO;
+                       return -EAGAIN;
+               }
+               if (ret == -ERESTARTSYS)
+                       ret = -EINTR;
+       } else if (zc->flags & IORING_RECVSEND_NOTIF_FLUSH) {
+               io_notif_slot_flush_submit(notif_slot, 0);
        }
 
-       if (zc->flags & IORING_RECVSEND_NOTIF_FLUSH)
-               io_notif_slot_flush_submit(notif_slot, 0);
+       if (ret >= 0)
+               ret += zc->done_io;
+       else if (zc->done_io)
+               ret = zc->done_io;
        io_req_set_res(req, ret, 0);
        return IOU_OK;
 }