rxrpc: Push iov_iter up from rxrpc_kernel_recv_data() to caller

Push iov_iter up from rxrpc_kernel_recv_data() to its caller to allow
non-contiguous iovs to be passed down, thereby permitting file reading to
be simplified in the AFS filesystem in a future patch.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 22 deletions

diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index a57ea96c84ea..816b19a78809 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -611,9 +611,7 @@ wait_error:
  * rxrpc_kernel_recv_data - Allow a kernel service to receive data/info
  * @sock: The socket that the call exists on
  * @call: The call to send data through
- * @buf: The buffer to receive into
- * @size: The size of the buffer, including data already read
- * @_offset: The running offset into the buffer.
+ * @iter: The buffer to receive into
  * @want_more: True if more data is expected to be read
  * @_abort: Where the abort code is stored if -ECONNABORTED is returned
  * @_service: Where to store the actual service ID (may be upgraded)
@@ -626,39 +624,30 @@ wait_error:
  * Note that we may return -EAGAIN to drain empty packets at the end of the
  * data, even if we've already copied over the requested data.
  *
- * This function adds the amount it transfers to *_offset, so this should be
- * precleared as appropriate.  Note that the amount remaining in the buffer is
- * taken to be size - *_offset.
- *
  * *_abort should also be initialised to 0.
  */
 int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
-			   void *buf, size_t size, size_t *_offset,
+			   struct iov_iter *iter,
 			   bool want_more, u32 *_abort, u16 *_service)
 {
-	struct iov_iter iter;
-	struct kvec iov;
+	size_t offset = 0;
 	int ret;
 
-	_enter("{%d,%s},%zu/%zu,%d",
+	_enter("{%d,%s},%zu,%d",
 	       call->debug_id, rxrpc_call_states[call->state],
-	       *_offset, size, want_more);
+	       iov_iter_count(iter), want_more);
 
-	ASSERTCMP(*_offset, <=, size);
 	ASSERTCMP(call->state, !=, RXRPC_CALL_SERVER_ACCEPTING);
 
-	iov.iov_base = buf + *_offset;
-	iov.iov_len = size - *_offset;
-	iov_iter_kvec(&iter, ITER_KVEC | READ, &iov, 1, size - *_offset);
-
 	mutex_lock(&call->user_mutex);
 
 	switch (READ_ONCE(call->state)) {
 	case RXRPC_CALL_CLIENT_RECV_REPLY:
 	case RXRPC_CALL_SERVER_RECV_REQUEST:
 	case RXRPC_CALL_SERVER_ACK_REQUEST:
-		ret = rxrpc_recvmsg_data(sock, call, NULL, &iter, size, 0,
-					 _offset);
+		ret = rxrpc_recvmsg_data(sock, call, NULL, iter,
+					 iov_iter_count(iter), 0,
+					 &offset);
 		if (ret < 0)
 			goto out;
 
@@ -667,7 +656,7 @@ int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
 		 * full buffer or have been given -EAGAIN.
 		 */
 		if (ret == 1) {
-			if (*_offset < size)
+			if (iov_iter_count(iter) > 0)
 				goto short_data;
 			if (!want_more)
 				goto read_phase_complete;
@@ -704,7 +693,7 @@ out:
 	if (_service)
 		*_service = call->service_id;
 	mutex_unlock(&call->user_mutex);
-	_leave(" = %d [%zu,%d]", ret, *_offset, *_abort);
+	_leave(" = %d [%zu,%d]", ret, iov_iter_count(iter), *_abort);
 	return ret;
 
 short_data:
@@ -720,7 +709,7 @@ call_complete:
 	ret = call->error;
 	if (call->completion == RXRPC_CALL_SUCCEEDED) {
 		ret = 1;
-		if (size > 0)
+		if (iov_iter_count(iter) > 0)
 			ret = -ECONNRESET;
 	}
 	goto out;