io_uring: support MSG_WAITALL for IORING_OP_SEND(MSG)

Like commit 7ba89d2af17a for recv/recvmsg, support MSG_WAITALL for the
send side. If this flag is set and we do a short send, retry for a
stream of seqpacket socket.

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

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 03134ec..e18d889 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5235,6 +5235,13 @@ static int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags)
 }
 
 #if defined(CONFIG_NET)
+static bool io_net_retry(struct socket *sock, int flags)
+{
+       if (!(flags & MSG_WAITALL))
+               return false;
+       return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
+}
+
 static int io_setup_async_msg(struct io_kiocb *req,
                              struct io_async_msghdr *kmsg)
 {
@@ -5293,12 +5300,14 @@ static int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        if (req->ctx->compat)
                sr->msg_flags |= MSG_CMSG_COMPAT;
 #endif
+       sr->done_io = 0;
        return 0;
 }
 
 static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
 {
        struct io_async_msghdr iomsg, *kmsg;
+       struct io_sr_msg *sr = &req->sr_msg;
        struct socket *sock;
        unsigned flags;
        int min_ret = 0;
@@ -5330,12 +5339,21 @@ static int io_sendmsg(struct io_kiocb *req, unsigned int issue_flags)
                        return io_setup_async_msg(req, kmsg);
                if (ret == -ERESTARTSYS)
                        ret = -EINTR;
+               if (ret > 0 && io_net_retry(sock, flags)) {
+                       sr->done_io += ret;
+                       req->flags |= REQ_F_PARTIAL_IO;
+                       return io_setup_async_msg(req, kmsg);
+               }
                req_set_fail(req);
        }
        /* fast path, check for non-NULL to avoid function call */
        if (kmsg->free_iov)
                kfree(kmsg->free_iov);
        req->flags &= ~REQ_F_NEED_CLEANUP;
+       if (ret >= 0)
+               ret += sr->done_io;
+       else if (sr->done_io)
+               ret = sr->done_io;
        __io_req_complete(req, issue_flags, ret, 0);
        return 0;
 }
@@ -5376,8 +5394,19 @@ static int io_send(struct io_kiocb *req, unsigned int issue_flags)
                        return -EAGAIN;
                if (ret == -ERESTARTSYS)
                        ret = -EINTR;
+               if (ret > 0 && io_net_retry(sock, flags)) {
+                       sr->len -= ret;
+                       sr->buf += ret;
+                       sr->done_io += ret;
+                       req->flags |= REQ_F_PARTIAL_IO;
+                       return -EAGAIN;
+               }
                req_set_fail(req);
        }
+       if (ret >= 0)
+               ret += sr->done_io;
+       else if (sr->done_io)
+               ret = sr->done_io;
        __io_req_complete(req, issue_flags, ret, 0);
        return 0;
 }
@@ -5509,13 +5538,6 @@ static int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
        return 0;
 }
 
-static bool io_net_retry(struct socket *sock, int flags)
-{
-       if (!(flags & MSG_WAITALL))
-               return false;
-       return sock->type == SOCK_STREAM || sock->type == SOCK_SEQPACKET;
-}
-
 static int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags)
 {
        struct io_async_msghdr iomsg, *kmsg;