Attachment 636738 Details for Bug 872254 – Save all domains when session bus dies or system is being shutdown

[patch] Save all domains when session bus dies or system is being shutdown

libvirt-save-with-session.patch (text/plain), 10.19 KB, created by Alexander Larsson on 2012-11-01 16:18:43 UTC

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Creator: Alexander Larsson

Created: 2012-11-01 16:18:43 UTC

Size: 10.19 KB

patch

obsolete

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>From: Alexander Larsson <alexl@redhat.com>
>To: libvir-list@redhat.com
>Cc: Alexander Larsson <alexl@redhat.com>
>Subject: [PATCH 2/2] Shut down session libvirtd cleanly
>Date: Tue,  9 Oct 2012 17:26:29 +0200
>Message-Id: <1349796389-6122-3-git-send-email-alexl@redhat.com>
>In-Reply-To: <1349796389-6122-1-git-send-email-alexl@redhat.com>
>References: <1349796389-6122-1-git-send-email-alexl@redhat.com>
>X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23
>
>When the session dies or when the system is going to be shut down
>we save all active VMs and exit libvirtd.
>
>Additionally whenever there is an active domain we hold a
>shutdown inhibitor to avoid shutting down before all the
>VMs are saved.
>---
> daemon/libvirtd.c | 244 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 244 insertions(+)
>
>diff --git a/daemon/libvirtd.c b/daemon/libvirtd.c
>index b49acc5..c3bf2ce 100644
>--- a/daemon/libvirtd.c
>+++ b/daemon/libvirtd.c
>@@ -98,6 +98,11 @@
> 
> #include "configmake.h"
> 
>+#ifdef HAVE_DBUS
>+# include <dbus/dbus.h>
>+# include "virdbus.h"
>+#endif
>+
> #if HAVE_SASL
> virNetSASLContextPtr saslCtxt = NULL;
> #endif
>@@ -769,6 +774,212 @@ static int daemonSetupSignals(virNetServerPtr srv)
>     return 0;
> }
> 
>+#ifdef HAVE_DBUS
>+
>+static DBusConnection *sessionBus;
>+static DBusConnection *systemBus;
>+static virConnectPtr sessionConnection;
>+static int numActiveDomains;
>+static bool hasInhibit;
>+static bool callingInhibit;
>+static int inhibitFd = -1;
>+
>+static void runSaveAllDomains(void *opaque)
>+{
>+    virNetServerPtr srv = opaque;
>+    int numDomains, i;
>+    int state;
>+    virDomainPtr *domains = NULL;
>+    unsigned int *flags = NULL;
>+
>+    numDomains = virConnectListAllDomains(sessionConnection, &domains,  VIR_CONNECT_LIST_DOMAINS_ACTIVE);
>+    if (numDomains < 0)
>+        goto cleanup;
>+
>+    if (VIR_ALLOC_N(flags, numDomains) < 0) {
>+        virReportOOMError();
>+        goto cleanup;
>+    }
>+
>+    /* First we pause all VMs to make them stop dirtying
>+       pages, etc. We remember if any VMs were paused so
>+       we can restore that on resume. */
>+    for (i = 0 ; i < numDomains ; i++) {
>+        flags[i] = VIR_DOMAIN_SAVE_RUNNING;
>+        if (virDomainGetState (domains[i], &state, NULL, 0) == 0) {
>+            if (state == VIR_DOMAIN_PAUSED) {
>+                flags[i] = VIR_DOMAIN_SAVE_PAUSED;
>+            }
>+        }
>+        virDomainSuspend (domains[i]);
>+    }
>+
>+    /* Then we save the VMs to disk */
>+    for (i = 0 ; i < numDomains ; i++)
>+        virDomainManagedSave (domains[i], flags[i]);
>+
>+    VIR_FREE (domains);
>+    VIR_FREE (flags);
>+
>+ cleanup:
>+    if (domains != NULL) {
>+        for (i = 0 ; i < numDomains ; i++)
>+            virDomainFree (domains[i]);
>+        VIR_FREE (domains);
>+    }
>+    if (flags != NULL)
>+        VIR_FREE (flags);
>+
>+    /* We don't need any shutdown inhibit lock anymore now */
>+    if (inhibitFd != -1) {
>+        if (VIR_CLOSE (inhibitFd) < 0)
>+            virReportSystemError(errno, "%s", _("failed to close file"));
>+        inhibitFd = -1;
>+    }
>+
>+    /* Exit libvirtd cleanly */
>+    virNetServerQuit (srv);
>+}
>+
>+/* We do this in a thread to not block the main loop */
>+static void saveAllDomains(virNetServerPtr srv)
>+{
>+    virThread thr;
>+    virObjectRef(srv);
>+    if (virThreadCreate(&thr, false, runSaveAllDomains, srv) < 0) {
>+        virObjectUnref(srv);
>+    }
>+}
>+
>+static void gotInhibitReply (DBusPendingCall *pending,
>+                             void            *opaque ATTRIBUTE_UNUSED)
>+{
>+    DBusMessage *reply;
>+    int fd;
>+
>+    callingInhibit = false;
>+
>+    reply = dbus_pending_call_steal_reply (pending);
>+    if (reply == NULL)
>+        return;
>+
>+    if (dbus_message_get_args (reply, NULL,
>+                                DBUS_TYPE_UNIX_FD, &fd,
>+                                DBUS_TYPE_INVALID)) {
>+        if (hasInhibit)
>+            inhibitFd = fd;
>+        else {
>+            /* We stopped the last VM since we made the inhibit call */
>+            if (VIR_CLOSE (fd) < 0) {
>+                virReportSystemError(errno, "%s", _("failed to close file"));
>+            }
>+        }
>+    }
>+    dbus_message_unref (reply);
>+}
>+
>+/* As per: http://www.freedesktop.org/wiki/Software/systemd/inhibit */
>+static void callInhibit(const char *what,
>+                        const char *who,
>+                        const char *why,
>+                        const char *mode)
>+{
>+    DBusMessage *message;
>+    DBusPendingCall *pendingReply;
>+
>+    if (systemBus == NULL)
>+        return;
>+
>+    /* Only one outstanding call at a time */
>+    if (callingInhibit)
>+        return;
>+
>+    message = dbus_message_new_method_call ("org.freedesktop.login1",
>+                                            "/org/freedesktop/login1",
>+                                            "org.freedesktop.login1.Manager",
>+                                            "Inhibit");
>+    if (message == NULL)
>+        return;
>+
>+    dbus_message_append_args (message,
>+                              DBUS_TYPE_STRING, &what,
>+                              DBUS_TYPE_STRING, &who,
>+                              DBUS_TYPE_STRING, &why,
>+                              DBUS_TYPE_STRING, &mode,
>+                              DBUS_TYPE_INVALID);
>+
>+    pendingReply = NULL;
>+    if (dbus_connection_send_with_reply (systemBus, message,
>+                                         &pendingReply,
>+                                         25*1000)) {
>+        dbus_pending_call_set_notify (pendingReply,
>+                                      gotInhibitReply,
>+                                      NULL, NULL);
>+        callingInhibit = true;
>+    }
>+    dbus_message_unref (message);
>+}
>+
>+
>+static void numActiveDomainsChanged(void)
>+{
>+    if (numActiveDomains > 0 && !hasInhibit) {
>+        callInhibit("shutdown", _("Libvirt"), _("Virtual machines need to be saved"), "delay");
>+        hasInhibit = true;
>+    } else if (numActiveDomains == 0 && hasInhibit) {
>+        if (inhibitFd != -1) {
>+            if (VIR_CLOSE (inhibitFd) < 0) {
>+                virReportSystemError(errno, "%s", _("failed to close file"));
>+            }
>+            inhibitFd = -1;
>+        }
>+        hasInhibit = false;
>+    }
>+}
>+
>+static int lifecycleEventCallback(virConnectPtr conn ATTRIBUTE_UNUSED,
>+                                  virDomainPtr dom ATTRIBUTE_UNUSED,
>+                                  int event,
>+                                  int detail ATTRIBUTE_UNUSED,
>+                                  void *opaque ATTRIBUTE_UNUSED)
>+{
>+    if (event == VIR_DOMAIN_EVENT_STOPPED)
>+        numActiveDomains--;
>+    else if (event == VIR_DOMAIN_EVENT_STARTED)
>+        numActiveDomains++;
>+
>+    numActiveDomainsChanged();
>+
>+    return 0;
>+}
>+
>+static DBusHandlerResult handleSessionMessageFunc(DBusConnection  *connection ATTRIBUTE_UNUSED,
>+                                                  DBusMessage     *message,
>+                                                  void            *userData)
>+{
>+    virNetServerPtr srv = userData;
>+
>+    if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
>+        saveAllDomains (srv);
>+    }
>+
>+    return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
>+}
>+
>+static DBusHandlerResult handleSystemMessageFunc(DBusConnection  *connection ATTRIBUTE_UNUSED,
>+                                                 DBusMessage     *message,
>+                                                 void            *userData)
>+{
>+    virNetServerPtr srv = userData;
>+
>+    if (dbus_message_is_signal(message, "org.freedesktop.login1.Manager", "PrepareForShutdown")) {
>+        saveAllDomains (srv);
>+    }
>+
>+    return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
>+}
>+#endif
>+
> static void daemonRunStateInit(void *opaque)
> {
>     virNetServerPtr srv = opaque;
>@@ -785,6 +996,39 @@ static void daemonRunStateInit(void *opaque)
>         return;
>     }
> 
>+#ifdef HAVE_DBUS
>+    /* Tie the non-priviledged libvirtd to the session/shutdown lifecycle */
>+    if (!virNetServerIsPrivileged(srv)) {
>+
>+        sessionBus = virDBusGetSessionBus ();
>+        if (sessionBus != NULL) {
>+            dbus_connection_add_filter(sessionBus,
>+                                       handleSessionMessageFunc, srv, NULL);
>+        }
>+
>+        systemBus = virDBusGetSystemBus ();
>+        if (systemBus != NULL) {
>+            dbus_connection_add_filter(systemBus,
>+                                       handleSystemMessageFunc, srv, NULL);
>+            dbus_bus_add_match(systemBus,
>+                               "type='signal',sender='org.freedesktop.login1', interface='org.freedesktop.login1.Manager'",
>+                               NULL);
>+        }
>+
>+        sessionConnection = virConnectOpen("qemu:///session");
>+        if (sessionConnection != NULL) {
>+            numActiveDomains = virConnectNumOfDomains(sessionConnection);
>+            virConnectDomainEventRegisterAny(sessionConnection,
>+                                             NULL,
>+                                             VIR_DOMAIN_EVENT_ID_LIFECYCLE,
>+                                             VIR_DOMAIN_EVENT_CALLBACK (lifecycleEventCallback),
>+                                             NULL, NULL);
>+            numActiveDomainsChanged();
>+        }
>+
>+    }
>+#endif
>+
>     /* Only now accept clients from network */
>     virNetServerUpdateServices(srv, true);
>     virObjectUnref(srv);
>-- 
>1.7.12.1
>

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Attachments on bug 872254: 636737 | 636738