From: Andrea Parri <[email protected]> Sent: Tuesday, September 8, 2020 12:54 AM > > > > @@ -300,6 +303,22 @@ int hv_ringbuffer_write(struct vmbus_channel > > > *channel, > > > kv_list[i].iov_len); > > > } > > > > > > + /* > > > + * Allocate the request ID after the data has been copied into the > > > + * ring buffer. Once this request ID is allocated, the completion > > > + * path could find the data and free it. > > > + */ > > > + > > > + if (desc->flags == VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED) { > > > + rqst_id = vmbus_next_request_id(&channel->requestor, requestid); > > > + if (rqst_id == VMBUS_RQST_ERROR) { > > > + pr_err("No request id available\n"); > > > + return -EAGAIN; > > > + } > > > + } > > > + desc = hv_get_ring_buffer(outring_info) + old_write; > > > + desc->trans_id = (rqst_id == VMBUS_NO_RQSTOR) ? requestid : rqst_id; > > > + > > > > This is a nit, but the above would be clearer to me if written like this: > > > > flags = desc->flags; > > if (flags == VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED) { > > rqst_id = vmbus_next_request_id(&channel->requestor, requestid); > > if (rqst_id == VMBUS_RQST_ERROR) { > > pr_err("No request id available\n"); > > return -EAGAIN; > > } > > } else { > > rqst_id = requestid; > > } > > desc = hv_get_ring_buffer(outring_info) + old_write; > > desc->trans_id = rqst_id; > > > > The value of the flags field controls what will be used as the value for the > > rqst_id. Having another test to see which value will be used as the > > trans_id > > somehow feels a bit redundant. And then rqst_id doesn't have to be > > initialized. > > Agreed, will apply in the next version. >
In an offline conversation, Andrea has pointed out that my proposed changes don't work. After a second look, I'll agreed that Andrea's code is the best that can be done, so my comments can be ignored. Michael
