From nobody Fri May 16 05:21:45 2025 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 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by mx.zohomail.com with SMTPS id 1501227869879553.2552699601099; Fri, 28 Jul 2017 00:44:29 -0700 (PDT) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id A476BA62F3; Fri, 28 Jul 2017 07:44:27 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 61BC94D739; Fri, 28 Jul 2017 07:44:27 +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 084CE3FCFC; Fri, 28 Jul 2017 07:44:27 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id v6S7iCN9016992 for ; Fri, 28 Jul 2017 03:44:12 -0400 Received: by smtp.corp.redhat.com (Postfix) id F09485C898; Fri, 28 Jul 2017 07:44:12 +0000 (UTC) Received: from beluga.usersys.redhat.com (unknown [10.43.2.36]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4D40A5C88A; Fri, 28 Jul 2017 07:44:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com A476BA62F3 Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx04.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=libvir-list-bounces@redhat.com From: Erik Skultety To: libvir-list@redhat.com Date: Fri, 28 Jul 2017 09:43:58 +0200 Message-Id: In-Reply-To: References: In-Reply-To: References: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-loop: libvir-list@redhat.com Cc: Erik Skultety Subject: [libvirt] [PATCH v2 1/5] nodedev: Introduce udevCheckMonitorFD helper function 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: , MIME-Version: 1.0 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 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Fri, 28 Jul 2017 07:44:28 +0000 (UTC) X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Type: text/plain; charset="utf-8" We need to perform some sanity checks on the udev monitor before every use so that we know nothing changed in the meantime. The reason for moving the code to a separate function is to be able to perform the same check from a worker thread that will replace the udevEventHandleCallback in terms of poking udev for device events. Signed-off-by: Erik Skultety --- src/node_device/node_device_udev.c | 56 +++++++++++++++++++++++-----------= ---- 1 file changed, 34 insertions(+), 22 deletions(-) diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_devi= ce_udev.c index dc9ed9e25..0b4e22f29 100644 --- a/src/node_device/node_device_udev.c +++ b/src/node_device/node_device_udev.c @@ -1616,42 +1616,54 @@ udevHandleOneDevice(struct udev_device *device) } =20 =20 -static void -udevEventHandleCallback(int watch ATTRIBUTE_UNUSED, - int fd, - int events ATTRIBUTE_UNUSED, - void *data ATTRIBUTE_UNUSED) +/* the caller must be holding the driver lock prior to calling this functi= on */ +static bool +udevCheckMonitorFD(struct udev_monitor *udev_monitor, int fd) { - struct udev_device *device =3D NULL; - struct udev_monitor *udev_monitor =3D NULL; - int udev_fd =3D -1; + int real_fd =3D -1; =20 - nodeDeviceLock(); - if (!(udev_monitor =3D DRV_STATE_UDEV_MONITOR(driver))) - goto error; + /* sanity check that the monitor socket hasn't changed */ + real_fd =3D udev_monitor_get_fd(udev_monitor); =20 - udev_fd =3D udev_monitor_get_fd(udev_monitor); - if (fd !=3D udev_fd) { + if (real_fd !=3D fd) { udevPrivate *priv =3D driver->privateData; =20 virReportError(VIR_ERR_INTERNAL_ERROR, _("File descriptor returned by udev %d does not " "match node device file descriptor %d"), - fd, udev_fd); + real_fd, fd); =20 - /* this is a non-recoverable error, let's remove the handle, so th= at we - * don't get in here again because of some spurious behaviour and = report - * the same error multiple times + /* this is a non-recoverable error, thus the event handle has to be + * removed, so that we don't get into the handler again because of= some + * spurious behaviour */ virEventRemoveHandle(priv->watch); - goto error; + return false; } =20 - device =3D udev_monitor_receive_device(udev_monitor); - if (device =3D=3D NULL) { + return true; +} + + +static void +udevEventHandleCallback(int watch ATTRIBUTE_UNUSED, + int fd, + int events ATTRIBUTE_UNUSED, + void *data ATTRIBUTE_UNUSED) +{ + struct udev_device *device =3D NULL; + struct udev_monitor *udev_monitor =3D NULL; + + nodeDeviceLock(); + udev_monitor =3D DRV_STATE_UDEV_MONITOR(driver); + + if (!udevCheckMonitorFD(udev_monitor, fd)) + goto unlock; + + if (!(device =3D udev_monitor_receive_device(udev_monitor))) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("udev_monitor_receive_device returned NULL")); - goto error; + goto unlock; } =20 nodeDeviceUnlock(); @@ -1661,7 +1673,7 @@ udevEventHandleCallback(int watch ATTRIBUTE_UNUSED, udev_device_unref(device); return; =20 - error: + unlock: nodeDeviceUnlock(); goto cleanup; } --=20 2.13.3 -- libvir-list mailing list libvir-list@redhat.com https://www.redhat.com/mailman/listinfo/libvir-list