Re: [libvirt] [PATCHv2 0.5/4] network: fix virNetworkObjAssignDef and persistence

Experimentation showed that if virNetworkCreateXML() was called for a network that was already defined, and then the network was subsequently shutdown, the network would continue to be persistent after the shutdown (expected/desired), but the original config would be lost in favor of the transient config sent in with virNetworkCreateXML() (which would then be the new persistent config) (obviously unexpected/not desired). To fix this, virNetworkObjAssignDef() has been changed to 1) properly save/free network->def and network->newDef for all the various combinations of live/active/persistent, including some combinations that were previously considered to be an error but didn't need to be (e.g. setting a "live" config for a network that isn't yet active but soon will be - that was previously considered an error, even though in practice it can be very useful). 2) automatically set the persistent flag whenever a new non-live config is assigned to the network (and clear it when the non-live config is set to NULL). the libvirt network driver no longer directly manipulates network->persistent, but instead relies entirely on virNetworkObjAssignDef() to do the right thing automatically. After this patch, the following sequence will behave as expected: virNetworkDefineXML(X) virNetworkCreateXML(X') (same name but some config different) virNetworkDestroy(X) At the end of these calls, the network config will remain as it was after the initial virNetworkDefine(), whereas previously it would take on the changes given during virNetworkCreateXML(). Another effect of this tighter coupling between a) setting a !live def and b) setting/clearing the "persistent" flag, is that future patches which change the details of network lifecycle management (e.g. upcoming patches to fix detection of "active" networks when libvirtd is restarted) will find it much more difficult to break persistence functionality. --- src/conf/network_conf.c | 78 +++++++++++++++++++++++---------------- src/conf/network_conf.h | 6 +-- src/network/bridge_driver.c | 34 +++++++---------- src/parallels/parallels_network.c | 4 +- src/test/test_driver.c | 5 +-- 5 files changed, 64 insertions(+), 63 deletions(-) diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c index 56c4a09..66945ce 100644 --- a/src/conf/network_conf.c +++ b/src/conf/network_conf.c @@ -302,46 +302,63 @@ void virNetworkObjListFree(virNetworkObjListPtr nets) /* * virNetworkObjAssignDef: * @network: the network object to update - * @def: the new NetworkDef (will be consumed by this function iff successful) + * @def: the new NetworkDef (will be consumed by this function) * @live: is this new def the "live" version, or the "persistent" version * - * Replace the appropriate copy of the given network's NetworkDef + * Replace the appropriate copy of the given network's def or newDef * with def. Use "live" and current state of the network to determine - * which to replace. + * which to replace and what to do with the old defs. When a non-live + * def is set, indicate that the network is now persistent. + * + * NB: a persistent network can be made transient by calling with: + * virNetworkObjAssignDef(network, NULL, false) (i.e. set the + * persistent def to NULL) * * Returns 0 on success, -1 on failure. */ -int +void

virNetworkObjAssignDef(virNetworkObjPtr network, virNetworkDefPtr def, bool live) { - if (virNetworkObjIsActive(network)) { - if (live) { + if (live) { + /* before setting new live def, save (into newDef) any + * existing persistent (!live) def to be restored when the + * network is destroyed, unless there is one already saved. + */ + if (network->persistent && !network->newDef) + network->newDef = network->def; + else virNetworkDefFree(network->def); - network->def = def; - } else if (network->persistent) { - /* save current configuration to be restored on network shutdown */ - virNetworkDefFree(network->newDef); + network->def = def; + } else { /* !live */ + virNetworkDefFree(network->newDef); + if (virNetworkObjIsActive(network)) { + /* save new configuration to be restored on network + * shutdown, leaving current live def alone + */ network->newDef = def; - } else { - virReportError(VIR_ERR_OPERATION_INVALID, - _("cannot save persistent config of transient " - "network '%s'"), network->def->name); - return -1; + } else { /* !live and !active */ + if (network->def && !network->persistent) { + /* network isn't (yet) marked active or persistent, + * but already has a "live" def set. This means we are + * currently setting the persistent def as a part of + * the process of starting the network, so we need to + * preserve the "not yet live" def in network->def. + */ + network->newDef = def; + } else { + /* either there is no live def set, or this network + * was already set as persistent, so the proper thing + * is to overwrite network->def. + */ + network->newDef = NULL;

+ virNetworkDefFree(network->def); + network->def = def;

+ } } - } else if (!live) { - virNetworkDefFree(network->newDef); - virNetworkDefFree(network->def); - network->newDef = NULL; - network->def = def; - } else { - virReportError(VIR_ERR_OPERATION_INVALID, - _("cannot save live config of inactive " - "network '%s'"), network->def->name); - return -1; + network->persistent = !!def; } - return 0; } /* @@ -365,10 +382,7 @@ virNetworkAssignDef(virNetworkObjListPtr nets, virNetworkObjPtr network; if ((network = virNetworkFindByName(nets, def->name))) { - if (virNetworkObjAssignDef(network, def, live) < 0) { - virNetworkObjUnlock(network); - return NULL; - } + virNetworkObjAssignDef(network, def, live); return network; } @@ -392,8 +406,9 @@ virNetworkAssignDef(virNetworkObjListPtr nets, ignore_value(virBitmapSetBit(network->class_id, 2)); network->def = def; - + network->persistent = !live; return network; + error: virNetworkObjUnlock(network); virNetworkObjFree(network); @@ -3118,7 +3133,6 @@ virNetworkObjPtr virNetworkLoadConfig(virNetworkObjListPtr nets, goto error; net->autostart = autostart; - net->persistent = 1; VIR_FREE(configFile); VIR_FREE(autostartLink); diff --git a/src/conf/network_conf.h b/src/conf/network_conf.h index 1a864de..90da16f 100644 --- a/src/conf/network_conf.h +++ b/src/conf/network_conf.h @@ -335,9 +335,9 @@ typedef bool (*virNetworkObjListFilter)(virConnectPtr conn, virNetworkObjPtr virNetworkAssignDef(virNetworkObjListPtr nets, virNetworkDefPtr def, bool live); -int virNetworkObjAssignDef(virNetworkObjPtr network, - virNetworkDefPtr def, - bool live); +void virNetworkObjAssignDef(virNetworkObjPtr network, + virNetworkDefPtr def, + bool live); int virNetworkObjSetDefTransient(virNetworkObjPtr network, bool live); void virNetworkObjUnsetDefTransient(virNetworkObjPtr network); virNetworkDefPtr virNetworkObjGetPersistentDef(virNetworkObjPtr network); diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index eb276cd..62d1c25 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -2667,10 +2667,11 @@ static virNetworkPtr networkCreateXML(virConnectPtr conn, const char *xml) if (networkValidate(driver, def, true) < 0) goto cleanup; - /* NB: "live" is false because this transient network hasn't yet - * been started + /* NB: even though this transient network hasn't yet been started, + * we assign the def with live = true in anticipation that it will + * be started momentarily. */ - if (!(network = virNetworkAssignDef(&driver->networks, def, false))) + if (!(network = virNetworkAssignDef(&driver->networks, def, true))) goto cleanup; def = NULL; @@ -2719,19 +2720,10 @@ static virNetworkPtr networkDefineXML(virConnectPtr conn, const char *xml) if (networkValidate(driver, def, false) < 0) goto cleanup; - if ((network = virNetworkFindByName(&driver->networks, def->name))) { - network->persistent = 1; - if (virNetworkObjAssignDef(network, def, false) < 0) - goto cleanup; - } else { - if (!(network = virNetworkAssignDef(&driver->networks, def, false))) - goto cleanup; - } - - /* define makes the network persistent - always */ - network->persistent = 1; + if (!(network = virNetworkAssignDef(&driver->networks, def, false))) + goto cleanup; - /* def was asigned */ + /* def was assigned to network object */ freeDef = false; if (virNetworkSaveConfig(driver->networkConfigDir, def) < 0) { @@ -2740,9 +2732,11 @@ static virNetworkPtr networkDefineXML(virConnectPtr conn, const char *xml) network = NULL; goto cleanup; } - network->persistent = 0; - virNetworkDefFree(network->newDef); - network->newDef = NULL; + /* if network was active already, just undo new persistent + * definition by making it transient. + * XXX - this isn't necessarily the correct thing to do. + */

+ virNetworkObjAssignDef(network, NULL, false); goto cleanup; } @@ -2794,10 +2788,8 @@ networkUndefine(virNetworkPtr net) goto cleanup; /* make the network transient */ - network->persistent = 0; network->autostart = 0; - virNetworkDefFree(network->newDef); - network->newDef = NULL; + virNetworkObjAssignDef(network, NULL, false);

event = virNetworkEventLifecycleNew(network->def->name, network->def->uuid, diff --git a/src/parallels/parallels_network.c b/src/parallels/parallels_network.c index cbb44b9..0ebeb7b 100644 --- a/src/parallels/parallels_network.c +++ b/src/parallels/parallels_network.c @@ -2,7 +2,7 @@ * parallels_network.c: core privconn functions for managing * Parallels Cloud Server hosts * - * Copyright (C) 2013 Red Hat, Inc. + * Copyright (C) 2013-2014 Red Hat, Inc. * Copyright (C) 2012 Parallels, Inc. * * This library is free software; you can redistribute it and/or @@ -231,7 +231,6 @@ parallelsLoadNetwork(parallelsConnPtr privconn, virJSONValuePtr jobj) goto cleanup; } net->active = 1; - net->persistent = 1; net->autostart = 1; virNetworkObjUnlock(net); return net; @@ -267,7 +266,6 @@ parallelsAddRoutedNetwork(parallelsConnPtr privconn) goto cleanup; } net->active = 1; - net->persistent = 1; net->autostart = 1; virNetworkObjUnlock(net); diff --git a/src/test/test_driver.c b/src/test/test_driver.c index 64f3daa..37756e7 100644 --- a/src/test/test_driver.c +++ b/src/test/test_driver.c @@ -784,7 +784,6 @@ testOpenDefault(virConnectPtr conn) goto error; } netobj->active = 1; - netobj->persistent = 1; virNetworkObjUnlock(netobj); if (!(interfacedef = virInterfaceDefParseString(defaultInterfaceXML))) @@ -1155,7 +1154,6 @@ testParseNetworks(testConnPtr privconn, goto error; } - obj->persistent = 1; obj->active = 1; virNetworkObjUnlock(obj); } @@ -3711,7 +3709,7 @@ static virNetworkPtr testNetworkCreateXML(virConnectPtr conn, const char *xml) if ((def = virNetworkDefParseString(xml)) == NULL) goto cleanup; - if (!(net = virNetworkAssignDef(&privconn->networks, def, false))) + if (!(net = virNetworkAssignDef(&privconn->networks, def, true))) goto cleanup; def = NULL; net->active = 1; @@ -3748,7 +3746,6 @@ virNetworkPtr testNetworkDefineXML(virConnectPtr conn, const char *xml) if (!(net = virNetworkAssignDef(&privconn->networks, def, false))) goto cleanup; def = NULL; - net->persistent = 1; event = virNetworkEventLifecycleNew(net->def->name, net->def->uuid, VIR_NETWORK_EVENT_DEFINED,