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 03A69C433EF for ; Mon, 18 Jul 2022 08:57:57 +0000 (UTC) Received: from localhost ([::1]:51388 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1oDMZh-0005gr-1H for qemu-devel@archiver.kernel.org; Mon, 18 Jul 2022 04:57:57 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33230) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oDMYH-0003jq-6h for qemu-devel@nongnu.org; Mon, 18 Jul 2022 04:56:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:42581) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1oDMYE-0003I4-0H for qemu-devel@nongnu.org; Mon, 18 Jul 2022 04:56:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1658134585; 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=zegPjovlNvloQp3J+bh0BPv6z2JSg6KVXkJLL3lCNDo=; b=UDRrukifImEsT/B4B2Jl4fLI8lML3sHcLRmaRh8KR//q/jRL5GTeNeKUJ9ungIPwF5S10A FzFoArthzCLm7KJPHxW0E8HbeUJP1wKqo9nq0lkHRIAFGebwrXGkDIFAKxQtTyuUFTQ18l LthXlucysSldFJG9qWQJKlZmtrJUkm4= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-248-ROvuTCu9PiugKMUz-cFzmg-1; Mon, 18 Jul 2022 04:56:21 -0400 X-MC-Unique: ROvuTCu9PiugKMUz-cFzmg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 22C8B2999B25; Mon, 18 Jul 2022 08:56:21 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.51]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E6FE12166B26; Mon, 18 Jul 2022 08:56:19 +0000 (UTC) Date: Mon, 18 Jul 2022 09:56:17 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Peter Delevoryas Cc: jsnow@redhat.com, crosa@redhat.com, bleal@redhat.com, f4bug@amsat.org, wainersm@redhat.com, qemu-devel@nongnu.org Subject: Re: [PATCH v2 1/1] python/machine: Fix AF_UNIX path too long on macOS Message-ID: References: <20220716173434.17183-1-peter@pjd.dev> <20220716173434.17183-2-peter@pjd.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20220716173434.17183-2-peter@pjd.dev> User-Agent: Mutt/2.2.6 (2022-06-05) X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 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: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham 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" On Sat, Jul 16, 2022 at 10:34:34AM -0700, Peter Delevoryas wrote: > On macOS, private $TMPDIR's are the default. These $TMPDIR's are > generated from a user's unix UID and UUID [1], which can create a > relatively long path: > > /var/folders/d7/rz20f6hd709c1ty8f6_6y_z40000gn/T/ > > QEMU's avocado tests create a temporary directory prefixed by > "avo_qemu_sock_", and create QMP sockets within _that_ as well. > The QMP socket is unnecessarily long, because a temporary directory > is created for every QEMUMachine object. > > /avo_qemu_sock_uh3w_dgc/qemu-37331-10bacf110-monitor.sock Looking at this again, I realize my suggestion for dealing with the second part of the path was mistaken. The "qemu-37331-10bacf110-monitor.sock" part is combining two pieces. First the result of f"qemu-{os.getpid()}-{id(self):02x}" is qemu-37331-10bacf110 and the code later than appends '-monitor.sock' So... > > The path limit for unix sockets on macOS is 104: [2] > > /* > * [XSI] Definitions for UNIX IPC domain. > */ > struct sockaddr_un { > unsigned char sun_len; /* sockaddr len including null */ > sa_family_t sun_family; /* [XSI] AF_UNIX */ > char sun_path[104]; /* [XSI] path name (gag) */ > }; > > This results in avocado tests failing on macOS because the QMP unix > socket can't be created, because the path is too long: > > ERROR| Failed to establish connection: OSError: AF_UNIX path too long > > This change reduces the size of both paths, and removes the unique > identification information from the socket name, since it seems to be > unnecessary. > > This commit produces paths like the following: > > pdel@pdel-mbp:/var/folders/d7/rz20f6hd709c1ty8f6_6y_z40000gn/T > $ tree qemu* > qemu_oc7h7f3u > ├── qmp-console.sock > └── qmp-monitor.sock > > [1] https://apple.stackexchange.com/questions/353832/why-is-mac-osx-temp-directory-in-weird-path > [2] /Library/Developer/CommandLineTools/SDKs/MacOSX12.3.sdk/usr/include/sys/un.h > > Signed-off-by: Peter Delevoryas > --- > python/qemu/machine/machine.py | 2 +- > tests/avocado/avocado_qemu/__init__.py | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py > index 37191f433b..b1823966b3 100644 > --- a/python/qemu/machine/machine.py > +++ b/python/qemu/machine/machine.py > @@ -157,7 +157,7 @@ def __init__(self, > self._wrapper = wrapper > self._qmp_timer = qmp_timer > > - self._name = name or f"qemu-{os.getpid()}-{id(self):02x}" > + self._name = name or "qmp" ...my suggestion here was wrong. We don't need the os.getpid() unoiqueness because the tmpdir already ensures that is safe, but keeping 'id(self)' is a good idea, if the test case creates multiple machines concurrently. Bearing in mind we later append '-monitor.sock' we don't need 'qmp' in the self._name. So on reflection I think I should have suggested using: self._name = name or f"{id(self):02x}" And *in addition*, a few lines later change: self._monitor_address = os.path.join( self.sock_dir, f"{self._name}-monitor.sock" ) To self._monitor_address = os.path.join( self.sock_dir, f"{self._name}.qmp" ) > diff --git a/tests/avocado/avocado_qemu/__init__.py b/tests/avocado/avocado_qemu/__init__.py > index ed4853c805..43b8c8848c 100644 > --- a/tests/avocado/avocado_qemu/__init__.py > +++ b/tests/avocado/avocado_qemu/__init__.py > @@ -296,7 +296,7 @@ def require_accelerator(self, accelerator): > "available" % accelerator) > > def _new_vm(self, name, *args): > - self._sd = tempfile.TemporaryDirectory(prefix="avo_qemu_sock_") > + self._sd = tempfile.TemporaryDirectory(prefix="qemu_") This bit is fine. > vm = QEMUMachine(self.qemu_bin, base_temp_dir=self.workdir, > sock_dir=self._sd.name, log_dir=self.logdir) > self.log.debug('QEMUMachine "%s" created', name) 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 :|