From nobody Sat Feb 7 15:35:27 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) client-ip=209.132.183.28; envelope-from=libvir-list-bounces@redhat.com; helo=mx1.redhat.com; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=libvir-list-bounces@redhat.com; dmarc=pass(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1562773702; cv=none; d=zoho.com; s=zohoarc; b=Xem3Bbplv+vmmqSq/IWK6N91E841rrFjJ8RJ7oe1dRFnafX9cheeoB3gbQsAF4okcz/9HsNKU8E/t1vlVWGmvMIje4rUWyOcT/MV1NT9XFYHWfXTOVBQotvcw4nrNKP6TnNLyQHcwUJgvjcgwT9jDqsX5LTbV/f0PDDA8aCxscE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1562773702; h=Content-Type:Content-Transfer-Encoding:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=LFse0likQZmVOFK/0AoB6qCyJDZo6f/7ytXbQLTtWog=; b=mKvbIKSBwPypsUsNbYhYfZ/wd3QiAMy8kxIYoHrzmuJIUdrliwMjMBc57WAsk6uM90+nVZRZ6sIC7JPcFaBwPIdh7VD1qZihFuyDI8bNORcKR9a8S/06xPlyWL1KjIQOUIwnk1uu1n3H9nW0w+68C1vNdu7qz2UmrDNAaMdTPuo= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of redhat.com designates 209.132.183.28 as permitted sender) smtp.mailfrom=libvir-list-bounces@redhat.com; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by mx.zohomail.com with SMTPS id 1562773702197956.4424941865732; Wed, 10 Jul 2019 08:48:22 -0700 (PDT) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 78241F9E88; Wed, 10 Jul 2019 15:48:20 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2DB5C60C7F; Wed, 10 Jul 2019 15:48:20 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id D3A5418433B3; Wed, 10 Jul 2019 15:48:19 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id x6AFmF0J017888 for ; Wed, 10 Jul 2019 11:48:15 -0400 Received: by smtp.corp.redhat.com (Postfix) id B64DF1001B11; Wed, 10 Jul 2019 15:48:15 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-112-53.ams2.redhat.com [10.36.112.53]) by smtp.corp.redhat.com (Postfix) with ESMTP id CF07D1001E9A; Wed, 10 Jul 2019 15:48:14 +0000 (UTC) From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= To: libvir-list@redhat.com Date: Wed, 10 Jul 2019 16:47:39 +0100 Message-Id: <20190710154741.17065-11-berrange@redhat.com> In-Reply-To: <20190710154741.17065-1-berrange@redhat.com> References: <20190710154741.17065-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-loop: libvir-list@redhat.com Subject: [libvirt] [PATCH 10/12] lxc: acquire a pidfile in the driver root directory X-BeenThere: libvir-list@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: Development discussions about the libvirt library & tools List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Sender: libvir-list-bounces@redhat.com Errors-To: libvir-list-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Wed, 10 Jul 2019 15:48:21 +0000 (UTC) When we allow multiple instances of the driver for the same user account, using a separate root directory, we need to ensure mutual exclusion. Use a pidfile to guarantee this. In privileged libvirtd this ends up locking /var/run/libvirt/lxc/driver.pid In unprivileged libvirtd this ends up locking /run/user/$UID/libvirt/lxc/run/driver.pid NB, the latter can vary depending on $XDG_RUNTIME_DIR Signed-off-by: Daniel P. Berrang=C3=A9 --- src/lxc/lxc_conf.h | 3 +++ src/lxc/lxc_driver.c | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/src/lxc/lxc_conf.h b/src/lxc/lxc_conf.h index dc5531ebf9..e26ca22d3c 100644 --- a/src/lxc/lxc_conf.h +++ b/src/lxc/lxc_conf.h @@ -70,6 +70,9 @@ struct _virLXCDriver { * then lockless thereafter */ virLXCDriverConfigPtr config; =20 + /* pid file FD, ensures two copies of the driver can't use the same ro= ot */ + int lockFD; + /* Require lock to get a reference on the object, * lockless access thereafter */ virCapsPtr caps; diff --git a/src/lxc/lxc_driver.c b/src/lxc/lxc_driver.c index 9db2a02dee..3982c24f34 100644 --- a/src/lxc/lxc_driver.c +++ b/src/lxc/lxc_driver.c @@ -1559,6 +1559,7 @@ static int lxcStateInitialize(bool privileged, =20 if (VIR_ALLOC(lxc_driver) < 0) return -1; + lxc_driver->lockFD =3D -1; if (virMutexInit(&lxc_driver->lock) < 0) { VIR_FREE(lxc_driver); return -1; @@ -1605,6 +1606,10 @@ static int lxcStateInitialize(bool privileged, goto cleanup; } =20 + if ((lxc_driver->lockFD =3D + virPidFileAcquire(cfg->stateDir, "driver", true, getpid())) < 0) + goto cleanup; + /* Get all the running persistent or transient configs first */ if (virDomainObjListLoadAllConfigs(lxc_driver->domains, cfg->stateDir, @@ -1696,6 +1701,10 @@ static int lxcStateCleanup(void) virObjectUnref(lxc_driver->caps); virObjectUnref(lxc_driver->securityManager); virObjectUnref(lxc_driver->xmlopt); + + if (lxc_driver->lockFD !=3D -1) + virPidFileRelease(lxc_driver->config->stateDir, "driver", lxc_driv= er->lockFD); + virObjectUnref(lxc_driver->config); virMutexDestroy(&lxc_driver->lock); VIR_FREE(lxc_driver); --=20 2.21.0 -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list