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 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0FCFEC021BB for ; Tue, 25 Feb 2025 17:58:32 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tmzC3-0004fX-M1; Tue, 25 Feb 2025 12:58:07 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tmzC1-0004ew-Sg for qemu-devel@nongnu.org; Tue, 25 Feb 2025 12:58:05 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tmzC0-00010t-4h for qemu-devel@nongnu.org; Tue, 25 Feb 2025 12:58:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1740506283; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=c2Is02KFbP4f2SP8aG8/as4uDCX3uLim7HjLYUtNl3M=; b=Uv8f1uyj+eRuB/mcuETBq/FmHoQPskS30Nn5am3t4u/luolMcuieXjKpjmVDK41ipAL7hp S2plps4LqaihdLuWTU1AqhozR3+o9PgJiZlUwfvBoU1wjcI6tHB1yCCm4GgzwykdwHw+bT u8zK+5RJK6f+Hcet75iiv6Y6FbP2eqk= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-180-OmTgD_bBOw6buVvaOzuTgg-1; Tue, 25 Feb 2025 12:57:58 -0500 X-MC-Unique: OmTgD_bBOw6buVvaOzuTgg-1 X-Mimecast-MFC-AGG-ID: OmTgD_bBOw6buVvaOzuTgg_1740506277 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8881C180034A; Tue, 25 Feb 2025 17:57:57 +0000 (UTC) Received: from redhat.com (unknown [10.42.28.59]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D36091800944; Tue, 25 Feb 2025 17:57:54 +0000 (UTC) Date: Tue, 25 Feb 2025 17:57:51 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Thomas Huth Cc: Kevin Wolf , Hanna Reitz , Eric Blake , Qemu-block , QEMU Developers , Stefan Hajnoczi Subject: Re: Problem with iotest 233 Message-ID: References: <5a31e4fb-3e0f-4455-9941-18b00287b276@redhat.com> <574cdf2e-6b8c-4ff3-9a2b-a7d00c92a788@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <574cdf2e-6b8c-4ff3-9a2b-a7d00c92a788@redhat.com> User-Agent: Mutt/2.2.13 (2024-03-09) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -24 X-Spam_score: -2.5 X-Spam_bar: -- X-Spam_report: (-2.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.443, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tue, Feb 25, 2025 at 06:52:43PM +0100, Thomas Huth wrote: > On 25/02/2025 18.44, Thomas Huth wrote: > > On 25/02/2025 11.12, Kevin Wolf wrote: > > > Am 25.02.2025 um 08:20 hat Thomas Huth geschrieben: > > > > > > > >   Hi! > > > > > > > > I'm facing a weird hang in iotest 233 on my Fedora 41 laptop. When running > > > > > > > >   ./check -raw 233 > > > > > > > > the test simply hangs. Looking at the log, the last message is "== check > > > > plain client to TLS server fails ==". I added some debug messages, and it > > > > seems like the previous NBD server is not correctly terminated here. > > > > The test works fine again if I apply this patch: > > > > > > > > diff --git a/tests/qemu-iotests/common.nbd b/tests/qemu-iotests/common.nbd > > > > --- a/tests/qemu-iotests/common.nbd > > > > +++ b/tests/qemu-iotests/common.nbd > > > > @@ -35,7 +35,7 @@ nbd_server_stop() > > > >           read NBD_PID < "$nbd_pid_file" > > > >           rm -f "$nbd_pid_file" > > > >           if [ -n "$NBD_PID" ]; then > > > > -            kill "$NBD_PID" > > > > +            kill -9 "$NBD_PID" > > > >           fi > > > >       fi > > > >       rm -f "$nbd_unix_socket" "$nbd_stderr_fifo" > > > > > > > > ... but that does not look like the right solution to me. What could prevent > > > > the qemu-nbd from correctly shutting down when it receives a normal SIGTERM > > > > signal? > > > > > > Not sure. In theory, qemu_system_killed() should set state = TERMINATE > > > and make main_loop_wait() return through the notification, which should > > > then make it shut down. Maybe you can attach gdb and check what 'state' > > > is when it hangs and if it's still in the main loop? > > > > I attached a gdb and ran "bt", and it looks like it is hanging in an > > exit() handler: > > > > (gdb) bt > > #0  0x00007f127f8fff1d in syscall () from /lib64/libc.so.6 > > #1  0x00007f127fd32e1d in g_cond_wait () from /lib64/libglib-2.0.so.0 > > #2  0x00005583df3048b2 in flush_trace_file (wait=true) at > > ../../devel/qemu/ trace/simple.c:140 > > #3  st_flush_trace_buffer () at ../../devel/qemu/trace/simple.c:383 > > #4  0x00007f127f8296c1 in __run_exit_handlers () from /lib64/libc.so.6 > > #5  0x00007f127f82978e in exit () from /lib64/libc.so.6 > > #6  0x00005583df1ae9e1 in main (argc=, argv= > out>) at ../../devel/qemu/qemu-nbd.c:1242 > > Ah, now that I wrote that: I recently ran "configure" with > --enable-trace-backends=simple ... when I remove that from "config.status" > again, then the test works fine again 8-) > > Still, I think it should not hang with the simple trace backend here, should it? IIUC this is waiting on trace_empty_cond. This condition should be signalled from wait_for_trace_records_available which is in turn called from writeout_thread. This thread is started from st_init, which is called from trace_init_backends which should be called from qemu-nbd. I would expect this thread to still be running when exit() handlers are run. Does GDB show any other threads running at the time of this hang ? With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|