From 2593f9692df0f128b14cde811e18aa49c1cf3e06 Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Tue, 24 May 2011 08:05:33 -0400 Subject: [PATCH] Fix the signature of virDomainMigrateFinish3 for error reporting The current virDomainMigrateFinish3 method signature attempts to distinguish two types of errors, by allowing return with ret== 0, but ddomain == NULL, to indicate a failure to start the guest. This is flawed, because when ret == 0, there is no way for the virErrorPtr details to be sent back to the client. Change the signature of virDomainMigrateFinish3 so it simply returns a virDomainPtr, in the same way as virDomainMigrateFinish2 The disk locking code will protect against the only possible failure mode this doesn't account for (loosing conenctivity to libvirtd after Finish3 starts the CPUs, but before the client sees the reply for Finish3). * src/driver.h, src/libvirt.c, src/libvirt_internal.h: Change virDomainMigrateFinish3 to return a virDomainPtr instead of int * src/remote/remote_driver.c, src/remote/remote_protocol.x, daemon/remote.c, src/qemu/qemu_driver.c, src/qemu/qemu_migration.c: Update for API change --- daemon/remote.c | 35 ++++++++------------------------ src/driver.h | 5 ++--- src/libvirt.c | 39 ++++++++++++++++++------------------ src/libvirt_internal.h | 21 +++++++++---------- src/qemu/qemu_driver.c | 21 +++++++++---------- src/qemu/qemu_migration.c | 19 +++++++++--------- src/remote/remote_driver.c | 29 ++++----------------------- src/remote/remote_protocol.x | 2 +- src/remote_protocol-structs | 2 +- 9 files changed, 64 insertions(+), 109 deletions(-) diff --git a/daemon/remote.c b/daemon/remote.c index f85d760b37..35129aacd2 100644 --- a/daemon/remote.c +++ b/daemon/remote.c @@ -76,7 +76,6 @@ static virStorageVolPtr get_nonnull_storage_vol(virConnectPtr conn, remote_nonnu static virSecretPtr get_nonnull_secret(virConnectPtr conn, remote_nonnull_secret secret); static virNWFilterPtr get_nonnull_nwfilter(virConnectPtr conn, remote_nonnull_nwfilter nwfilter); static virDomainSnapshotPtr get_nonnull_domain_snapshot(virDomainPtr dom, remote_nonnull_domain_snapshot snapshot); -static int make_domain(remote_domain *dom_dst, virDomainPtr dom_src); static void make_nonnull_domain(remote_nonnull_domain *dom_dst, virDomainPtr dom_src); static void make_nonnull_network(remote_nonnull_network *net_dst, virNetworkPtr net_src); static void make_nonnull_interface(remote_nonnull_interface *interface_dst, virInterfacePtr interface_src); @@ -3359,19 +3358,16 @@ remoteDispatchDomainMigrateFinish3(struct qemud_server *server ATTRIBUTE_UNUSED, uri = args->uri == NULL ? NULL : *args->uri; dconnuri = args->dconnuri == NULL ? NULL : *args->dconnuri; - if (virDomainMigrateFinish3(conn, args->dname, - args->cookie_in.cookie_in_val, - args->cookie_in.cookie_in_len, - &cookieout, &cookieoutlen, - dconnuri, uri, - args->flags, - args->cancelled, - &dom) < 0) + if (!(dom = virDomainMigrateFinish3(conn, args->dname, + args->cookie_in.cookie_in_val, + args->cookie_in.cookie_in_len, + &cookieout, &cookieoutlen, + dconnuri, uri, + args->flags, + args->cancelled))) goto cleanup; - if (dom && - make_domain(&ret->ddom, dom) < 0) - goto cleanup; + make_nonnull_domain(&ret->dom, dom); /* remoteDispatchClientRequest will free cookie */ @@ -3493,21 +3489,6 @@ get_nonnull_domain_snapshot(virDomainPtr dom, remote_nonnull_domain_snapshot sna } /* Make remote_nonnull_domain and remote_nonnull_network. */ -static int -make_domain(remote_domain *dom_dst, virDomainPtr dom_src) -{ - remote_domain rdom; - if (VIR_ALLOC(rdom) < 0) - return -1; - - rdom->id = dom_src->id; - rdom->name = strdup(dom_src->name); - memcpy(rdom->uuid, dom_src->uuid, VIR_UUID_BUFLEN); - - *dom_dst = rdom; - return 0; -} - static void make_nonnull_domain(remote_nonnull_domain *dom_dst, virDomainPtr dom_src) { diff --git a/src/driver.h b/src/driver.h index a5d8fe5fa5..875ffcb336 100644 --- a/src/driver.h +++ b/src/driver.h @@ -587,7 +587,7 @@ typedef int const char *dname, unsigned long resource); -typedef int +typedef virDomainPtr (*virDrvDomainMigrateFinish3) (virConnectPtr dconn, const char *dname, @@ -598,8 +598,7 @@ typedef int const char *dconnuri, const char *uri, unsigned long flags, - int cancelled, - virDomainPtr *newdom); + int cancelled); typedef int (*virDrvDomainMigrateConfirm3) diff --git a/src/libvirt.c b/src/libvirt.c index 8f9b6cebda..39c3213664 100644 --- a/src/libvirt.c +++ b/src/libvirt.c @@ -3829,18 +3829,19 @@ finish: cookieout = NULL; cookieoutlen = 0; dname = dname ? dname : domain->name; - ret = dconn->driver->domainMigrateFinish3 + ddomain = dconn->driver->domainMigrateFinish3 (dconn, dname, cookiein, cookieinlen, &cookieout, &cookieoutlen, - NULL, uri, flags, cancelled, &ddomain); + NULL, uri, flags, cancelled); - /* If ret is 0 then 'ddomain' indicates whether the VM is - * running on the dest. If not running, we can restart - * the source. If ret is -1, we can't be sure what happened - * to the VM on the dest, thus the only safe option is to - * kill the VM on the source, even though that may leave - * no VM at all on either host. + /* If ddomain is NULL, then we were unable to start + * the guest on the target, and must restart on the + * source. There is a small chance that the ddomain + * is NULL due to an RPC failure, in which case + * ddomain could in fact be running on the dest. + * The lock manager plugins should take care of + * safety in this scenario. */ - cancelled = ret == 0 && ddomain == NULL ? 1 : 0; + cancelled = ddomain == NULL ? 1 : 0; /* If finish3 set an error, and we don't have an earlier * one we need to preserve it in case confirm3 overwrites @@ -5158,7 +5159,7 @@ error: * Not for public use. This function is part of the internal * implementation of migration in the remote case. */ -int +virDomainPtr virDomainMigrateFinish3(virConnectPtr dconn, const char *dname, const char *cookiein, @@ -5168,20 +5169,19 @@ virDomainMigrateFinish3(virConnectPtr dconn, const char *dconnuri, const char *uri, unsigned long flags, - int cancelled, - virDomainPtr *newdom) + int cancelled) { VIR_DEBUG("dconn=%p, dname=%s, cookiein=%p, cookieinlen=%d, cookieout=%p," - "cookieoutlen=%p, dconnuri=%s, uri=%s, flags=%lu, retcode=%d newdom=%p", + "cookieoutlen=%p, dconnuri=%s, uri=%s, flags=%lu, retcode=%d", dconn, NULLSTR(dname), cookiein, cookieinlen, cookieout, - cookieoutlen, NULLSTR(dconnuri), NULLSTR(uri), flags, cancelled, newdom); + cookieoutlen, NULLSTR(dconnuri), NULLSTR(uri), flags, cancelled); virResetLastError(); if (!VIR_IS_CONNECT (dconn)) { virLibConnError(VIR_ERR_INVALID_CONN, __FUNCTION__); virDispatchError(NULL); - return -1; + return NULL; } if (dconn->flags & VIR_CONNECT_RO) { @@ -5190,14 +5190,13 @@ virDomainMigrateFinish3(virConnectPtr dconn, } if (dconn->driver->domainMigrateFinish3) { - int ret; + virDomainPtr ret; ret = dconn->driver->domainMigrateFinish3(dconn, dname, cookiein, cookieinlen, cookieout, cookieoutlen, dconnuri, uri, flags, - cancelled, - newdom); - if (ret < 0) + cancelled); + if (!ret) goto error; return ret; } @@ -5206,7 +5205,7 @@ virDomainMigrateFinish3(virConnectPtr dconn, error: virDispatchError(dconn); - return -1; + return NULL; } diff --git a/src/libvirt_internal.h b/src/libvirt_internal.h index 1d71a6cf52..83c25fceb8 100644 --- a/src/libvirt_internal.h +++ b/src/libvirt_internal.h @@ -167,17 +167,16 @@ int virDomainMigratePerform3(virDomainPtr dom, const char *dname, unsigned long resource); -int virDomainMigrateFinish3(virConnectPtr dconn, - const char *dname, - const char *cookiein, - int cookieinlen, - char **cookieout, - int *cookieoutlen, - const char *dconnuri, /* libvirtd URI if Peer2Peer, NULL otherwise */ - const char *uri, /* VM Migration URI, NULL in tunnelled case */ - unsigned long flags, - int cancelled, /* Kill the dst VM */ - virDomainPtr *newdom); +virDomainPtr virDomainMigrateFinish3(virConnectPtr dconn, + const char *dname, + const char *cookiein, + int cookieinlen, + char **cookieout, + int *cookieoutlen, + const char *dconnuri, /* libvirtd URI if Peer2Peer, NULL otherwise */ + const char *uri, /* VM Migration URI, NULL in tunnelled case */ + unsigned long flags, + int cancelled); /* Kill the dst VM */ int virDomainMigrateConfirm3(virDomainPtr domain, const char *cookiein, diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index df6e1c2bef..6511ffd976 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -6232,7 +6232,7 @@ cleanup: } -static int +static virDomainPtr qemuDomainMigrateFinish3(virConnectPtr dconn, const char *dname, const char *cookiein, @@ -6242,12 +6242,11 @@ qemuDomainMigrateFinish3(virConnectPtr dconn, const char *dconnuri ATTRIBUTE_UNUSED, const char *uri ATTRIBUTE_UNUSED, unsigned long flags, - int cancelled, - virDomainPtr *newdom) + int cancelled) { struct qemud_driver *driver = dconn->privateData; virDomainObjPtr vm; - int ret = -1; + virDomainPtr dom = NULL; virCheckFlags(VIR_MIGRATE_LIVE | VIR_MIGRATE_PEER2PEER | @@ -6256,7 +6255,7 @@ qemuDomainMigrateFinish3(virConnectPtr dconn, VIR_MIGRATE_UNDEFINE_SOURCE | VIR_MIGRATE_PAUSED | VIR_MIGRATE_NON_SHARED_DISK | - VIR_MIGRATE_NON_SHARED_INC, -1); + VIR_MIGRATE_NON_SHARED_INC, NULL); qemuDriverLock(driver); vm = virDomainFindByName(&driver->domains, dname); @@ -6266,16 +6265,14 @@ qemuDomainMigrateFinish3(virConnectPtr dconn, goto cleanup; } - *newdom = qemuMigrationFinish(driver, dconn, vm, - cookiein, cookieinlen, - cookieout, cookieoutlen, - flags, cancelled, true); - - ret = 0; + dom = qemuMigrationFinish(driver, dconn, vm, + cookiein, cookieinlen, + cookieout, cookieoutlen, + flags, cancelled, true); cleanup: qemuDriverUnlock(driver); - return ret; + return dom; } static int diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 660365568c..2f0ed28765 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1942,19 +1942,20 @@ finish: cookieoutlen = 0; dname = dname ? dname : vm->def->name; qemuDomainObjEnterRemoteWithDriver(driver, vm); - ret = dconn->driver->domainMigrateFinish3 + ddomain = dconn->driver->domainMigrateFinish3 (dconn, dname, cookiein, cookieinlen, &cookieout, &cookieoutlen, - dconnuri, uri_out ? uri_out : uri, flags, cancelled, &ddomain); + dconnuri, uri_out ? uri_out : uri, flags, cancelled); qemuDomainObjExitRemoteWithDriver(driver, vm); - /* If ret is 0 then 'ddomain' indicates whether the VM is - * running on the dest. If not running, we can restart - * the source. If ret is -1, we can't be sure what happened - * to the VM on the dest, thus the only safe option is to - * kill the VM on the source, even though that may leave - * no VM at all on either host. + /* If ddomain is NULL, then we were unable to start + * the guest on the target, and must restart on the + * source. There is a small chance that the ddomain + * is NULL due to an RPC failure, in which case + * ddomain could in fact be running on the dest. + * The lock manager plugins should take care of + * safety in this scenario. */ - cancelled = ret == 0 && ddomain == NULL ? 1 : 0; + cancelled = ddomain == NULL ? 1 : 0; /* If finish3 set an error, and we don't have an earlier * one we need to preserve it in case confirm3 overwrites diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c index 64f56201fa..14f9908270 100644 --- a/src/remote/remote_driver.c +++ b/src/remote/remote_driver.c @@ -238,7 +238,6 @@ static int remoteAuthPolkit (virConnectPtr conn, struct private_data *priv, int virReportErrorHelper(VIR_FROM_REMOTE, code, __FILE__, \ __FUNCTION__, __LINE__, __VA_ARGS__) -static virDomainPtr get_domain (virConnectPtr conn, remote_domain domain); static virDomainPtr get_nonnull_domain (virConnectPtr conn, remote_nonnull_domain domain); static virNetworkPtr get_nonnull_network (virConnectPtr conn, remote_nonnull_network network); static virNWFilterPtr get_nonnull_nwfilter (virConnectPtr conn, remote_nonnull_nwfilter nwfilter); @@ -5228,7 +5227,7 @@ error: } -static int +static virDomainPtr remoteDomainMigrateFinish3(virConnectPtr dconn, const char *dname, const char *cookiein, @@ -5238,17 +5237,15 @@ remoteDomainMigrateFinish3(virConnectPtr dconn, const char *dconnuri, const char *uri, unsigned long flags, - int cancelled, - virDomainPtr *ddom) + int cancelled) { remote_domain_migrate_finish3_args args; remote_domain_migrate_finish3_ret ret; struct private_data *priv = dconn->privateData; - int rv = -1; + virDomainPtr rv = NULL; remoteDriverLock(priv); - *ddom = NULL; memset(&args, 0, sizeof(args)); memset(&ret, 0, sizeof(ret)); @@ -5265,7 +5262,7 @@ remoteDomainMigrateFinish3(virConnectPtr dconn, (xdrproc_t) xdr_remote_domain_migrate_finish3_ret, (char *) &ret) == -1) goto done; - *ddom = get_domain(dconn, ret.ddom); + rv = get_nonnull_domain(dconn, ret.dom); if (ret.cookie_out.cookie_out_len > 0) { if (!cookieout || !cookieoutlen) { @@ -5281,8 +5278,6 @@ remoteDomainMigrateFinish3(virConnectPtr dconn, xdr_free ((xdrproc_t) &xdr_remote_domain_migrate_finish3_ret, (char *) &ret); - rv = 0; - done: remoteDriverUnlock(priv); return rv; @@ -6608,22 +6603,6 @@ remoteDomainEventQueue(struct private_data *priv, virDomainEventPtr event) virDomainEventStateQueue(priv->domainEventState, event); } -/* get_nonnull_domain and get_nonnull_network turn an on-wire - * (name, uuid) pair into virDomainPtr or virNetworkPtr object. - * These can return NULL if underlying memory allocations fail, - * but if they do then virterror_internal.has been set. - */ -static virDomainPtr -get_domain (virConnectPtr conn, remote_domain domain) -{ - virDomainPtr dom = NULL; - if (domain) { - dom = virGetDomain (conn, domain->name, BAD_CAST domain->uuid); - if (dom) dom->id = domain->id; - } - return dom; -} - /* get_nonnull_domain and get_nonnull_network turn an on-wire * (name, uuid) pair into virDomainPtr or virNetworkPtr object. * These can return NULL if underlying memory allocations fail, diff --git a/src/remote/remote_protocol.x b/src/remote/remote_protocol.x index 58afee02c9..d8c0e532d1 100644 --- a/src/remote/remote_protocol.x +++ b/src/remote/remote_protocol.x @@ -2035,7 +2035,7 @@ struct remote_domain_migrate_finish3_args { }; struct remote_domain_migrate_finish3_ret { - remote_domain ddom; + remote_nonnull_domain dom; opaque cookie_out; }; diff --git a/src/remote_protocol-structs b/src/remote_protocol-structs index b6cef13315..e78338e90d 100644 --- a/src/remote_protocol-structs +++ b/src/remote_protocol-structs @@ -1534,7 +1534,7 @@ struct remote_domain_migrate_finish3_args { int cancelled; }; struct remote_domain_migrate_finish3_ret { - remote_domain ddom; + remote_nonnull_domain dom; struct { u_int cookie_out_len; char * cookie_out_val;