Re: [libvirt] [PATCH v4 1/7] nodedev: Introduce udevEventCheckMonitorFD helper function

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 <eskultet(a)redhat.com&gt; --- src/node_device/node_device_udev.c | 40 +++++++++++++++++++++++++------------- 1 file changed, 27 insertions(+), 13 deletions(-) diff --git a/src/node_device/node_device_udev.c b/src/node_device/node_device_udev.c index f4177455c..fe21ad7df 100644 --- a/src/node_device/node_device_udev.c +++ b/src/node_device/node_device_udev.c @@ -1615,14 +1615,10 @@ udevHandleOneDevice(struct udev_device *device) } -static void -udevEventHandleCallback(int watch ATTRIBUTE_UNUSED, - int fd, - int events ATTRIBUTE_UNUSED, - void *data ATTRIBUTE_UNUSED) +static bool +udevEventCheckMonitorFD(struct udev_monitor *udev_monitor, + int fd) { - struct udev_device *device = NULL; - struct udev_monitor *udev_monitor = DRV_STATE_UDEV_MONITOR(driver); int udev_fd = -1; udev_fd = udev_monitor_get_fd(udev_monitor); @@ -1641,21 +1637,39 @@ udevEventHandleCallback(int watch ATTRIBUTE_UNUSED, virEventRemoveHandle(priv->watch); priv->watch = -1; - goto cleanup; + return false; + } + + return true; +} + + +static void +udevEventHandleCallback(int watch ATTRIBUTE_UNUSED, + int fd, + int events ATTRIBUTE_UNUSED, + void *data ATTRIBUTE_UNUSED) +{ + struct udev_device *device = NULL; + struct udev_monitor *udev_monitor = NULL; + + udev_monitor = DRV_STATE_UDEV_MONITOR(driver); + + if (!udevEventCheckMonitorFD(udev_monitor, fd)) { + nodeDeviceUnlock();

+ return; } device = udev_monitor_receive_device(udev_monitor); - if (device == NULL) { + + if (!device) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("udev_monitor_receive_device returned NULL")); - goto cleanup; + return; } udevHandleOneDevice(device); - - cleanup: udev_device_unref(device); - return; }