From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7C769C43603 for ; Wed, 3 Mar 2021 00:12:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5685964FC4 for ; Wed, 3 Mar 2021 00:12:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233499AbhCCABV (ORCPT ); Tue, 2 Mar 2021 19:01:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:45812 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1448442AbhCBOUb (ORCPT ); Tue, 2 Mar 2021 09:20:31 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E848264F12; Tue, 2 Mar 2021 14:19:50 +0000 (UTC) Date: Tue, 2 Mar 2021 09:19:49 -0500 From: Steven Rostedt To: Tzvetomir Stoyanov Cc: Linux Trace Devel Subject: Re: [PATCH 6/8] trace-cmd output: Set file_state of output handle after copy of headers Message-ID: <20210302091949.263d02c8@gandalf.local.home> In-Reply-To: References: <20210301143724.540985351@goodmis.org> <20210301143857.541050724@goodmis.org> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On Tue, 2 Mar 2021 10:10:24 +0200 Tzvetomir Stoyanov wrote: > On Mon, Mar 1, 2021 at 4:38 PM Steven Rostedt wrote: > > > > From: "Steven Rostedt (VMware)" > > > > Now that the input and output handles know the state they are at in reading > > or writing, the tracecmd_copy() has to set the state of the output handle it > > creates. > > > > Signed-off-by: Steven Rostedt (VMware) > > --- > > lib/trace-cmd/trace-output.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c > > index 6d504cbaf133..1156899a85d3 100644 > > --- a/lib/trace-cmd/trace-output.c > > +++ b/lib/trace-cmd/trace-output.c > > @@ -1656,6 +1656,8 @@ struct tracecmd_output *tracecmd_copy(struct tracecmd_input *ihandle, > > if (tracecmd_copy_headers(ihandle, handle->fd) < 0) > > goto out_free; > > > > + handle->file_state = TRACECMD_FILE_CMD_LINES; > > Why is the state overwritten here, isn't it more logical to be set in > tracecmd_copy_headers(), by each function that copies a header to set That's because the handle is not passed into tracecmd_copy_headers. And because the handle is a struct tracecmd_output, the tracecmd_copy_headers() which is in trace-input.c doesn't have access to this structure, and I prefer to keep it that way. That said, we could modify tracecmd_copy_header() to return the state that it copied up to, or negative on error. state = tracecmd_copy_headers(ihandle, handle->fd); if (state < 0) goto out_free; handle->file_state = state; That would be more robust! -- Steve > the relevant state. The last call in tracecmd_copy_headers() > is copy_command_lines(), which should set state to > TRACECMD_FILE_CMD_LINES in case of success. > The state is already TRACECMD_FILE_CMD_LINES > in tracecmd_copy_headers(), but right before its exit it > is overwritten to the old file state. And here again it is > overwritten back to TRACECMD_FILE_CMD_LINES. > May be I miss something here, cannot understand the logic. > > > + > > /* The file is all ready to have cpu data attached */ > > return handle; > > > > -- > > 2.30.0 > > > > > >