<div dir="ltr"><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small;color:#000000"> </div><div class="gmail_extra"> <div class="gmail_quote">On Mon, Aug 11, 2014 at 7:04 PM, Christophe Fergeau <<a href="mailto:cfergeau@redhat.com" target="_blank">cfergeau@redhat.com</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="HOEnZb"><div class="h5">On Sat, Aug 09, 2014 at 06:40:22PM +0800, Cody Chan wrote: > After dragging a zero-size file, then I open it in guest, > I get a warning message box which says: > "the process cannot access the file because it is being used by another > process". > And I get to know the file is occupied by vdagent. Now we look back the > process: > > a) When dragging a zero-size file, spice-gtk gets the name and size, then > sends > the message to vd_agent with VD_AGENT_FILE_XFER_START > b) vd_agent receives and parsers the message, then gets file name and size, > creates(open) > the file and gets the handler, at last, sends > VD_AGENT_FILE_XFER_STATUS_CAN_SEND_DATA > c) spice-gtk receives the VD_AGENT_FILE_XFER_STATUS_CAN_SEND_DATA message, > the sends data with VD_AGENT_FILE_XFER_DATA > d) vd_agent receives and writes data to the file opened > e) After finishing the writing, vd_agent closes the handler > > But in step c, we take a look the code: > //spice-channel.c > >static void file_xfer_read_cb(...) > >{ > > //... > > count = g_input_stream_read_finish(G_INPUT_STREAM(task->file_stream), > res, &error); > > if (count > 0) { > > task->read_bytes += count; > > file_xfer_queue(task, count); > > file_xfer_flush_async(channel, task->cancellable, > > file_xfer_data_flushed_cb, task); > > task->pending = TRUE; > > } else if (error) { > > VDAgentFileXferStatusMessage msg = { > > .id = task->id, > > .result = VD_AGENT_FILE_XFER_STATUS_ERROR, > > }; > > agent_msg_queue_many(task->channel, VD_AGENT_FILE_XFER_STATUS, > > &msg, sizeof(msg), NULL); > > spice_channel_wakeup(SPICE_CHANNEL(task->channel), FALSE); > > file_xfer_completed(task, error); > > } > >} > > If count == 0, then it does nothing! > Then vd_agent will receive nothing after opening a file, and always occupy > the file. > Here we close the file if file_size = 0, even though it doesn't make sense > to send > a zero-size file. </div></div>Ah, good catch, from a quick look it seems the linux agent does not handle this case properly either. This can be fixed in both agents, or alternatively, this can also be fixed in spice-gtk in file_xfer_read_cb by sending a dummy empty data message when the file size is 0. Fixing it in the agents is probably less convoluted. </blockquote><div> </div><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small;color:rgb(0,0,0)">As you've proposed, I fix the bug in spice-gtk, and I'll send a new patch after testing.</div> <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"> <div class=""> > > > --- > vdagent/file_xfer.cpp | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/vdagent/file_xfer.cpp b/vdagent/file_xfer.cpp > index 34a9ee6..17d842e 100644 > --- a/vdagent/file_xfer.cpp > +++ b/vdagent/file_xfer.cpp > @@ -89,6 +89,10 @@ void FileXfer::handle_start(VDAgentFileXferStartMessage* > start, > vd_printf("failed creating %s %lu", file_path, GetLastError()); > return; > } > + if (file_size == 0){ > + CloseHandle(handle); > + return; > + } </div>The agent should probably return VD_AGENT_FILE_XFER_STATUS_SUCCESS in this case to let the client know this is over. Christophe </blockquote></div> <div> </div>-- <div dir="ltr">QSBDT0RFUiBGUk9NIFJJRVNUIE9GIENUU0VV</div> </div></div>