From 630ee5ac6cf4e3be3f3e986897a289865dd2604b Mon Sep 17 00:00:00 2001 From: Peter Krempa Date: Mon, 30 Mar 2015 11:26:20 +0200 Subject: [PATCH] qemu: blockjob: Synchronously update backing chain in XML on ABORT/PIVOT When the synchronous pivot option is selected, libvirt would not update the backing chain until the job was exitted. Some applications then received invalid data as their job serialized first. This patch removes polling to wait for the ABORT/PIVOT job completion and replaces it with a condition. If a synchronous operation is requested the update of the XML is executed in the job of the caller of the synchronous request. Otherwise the monitor event callback uses a separate worker to update the backing chain with a new job. This is a regression since 1a92c719101e5bfa6fe2b78006ad04c7f075ea28 When the ABORT job is finished synchronously you get the following call stack: #0 qemuBlockJobEventProcess #1 qemuDomainBlockJobImpl #2 qemuDomainBlockJobAbort #3 virDomainBlockJobAbort While previously or while using the _ASYNC flag you'd get: #0 qemuBlockJobEventProcess #1 processBlockJobEvent #2 qemuProcessEventHandler #3 virThreadPoolWorker --- src/conf/domain_conf.c | 16 ++++++++++++++- src/conf/domain_conf.h | 6 ++++++ src/qemu/qemu_driver.c | 45 +++++++++++++++++------------------------ src/qemu/qemu_process.c | 38 ++++++++++++++++++++++------------ 4 files changed, 65 insertions(+), 40 deletions(-) diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index 9324de065c..cd6ee22e57 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -1289,9 +1289,22 @@ virDomainDiskDefNew(void) if (VIR_ALLOC(ret) < 0) return NULL; + if (VIR_ALLOC(ret->src) < 0) - VIR_FREE(ret); + goto error; + + if (virCondInit(&ret->blockJobSyncCond) < 0) { + virReportSystemError(errno, "%s", _("Failed to initialize condition")); + goto error; + } + return ret; + + error: + virStorageSourceFree(ret->src); + VIR_FREE(ret); + + return NULL; } @@ -1310,6 +1323,7 @@ virDomainDiskDefFree(virDomainDiskDefPtr def) VIR_FREE(def->product); VIR_FREE(def->domain_name); virDomainDeviceInfoClear(&def->info); + virCondDestroy(&def->blockJobSyncCond); VIR_FREE(def); } diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 608f61f0e3..84e880a6d7 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -685,6 +685,12 @@ struct _virDomainDiskDef { int mirrorState; /* enum virDomainDiskMirrorState */ int mirrorJob; /* virDomainBlockJobType */ + /* for some synchronous block jobs, we need to notify the owner */ + virCond blockJobSyncCond; + int blockJobType; /* type of the block job from the event */ + int blockJobStatus; /* status of the finished block job */ + bool blockJobSync; /* the block job needs synchronized termination */ + struct { unsigned int cylinders; unsigned int heads; diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 5a90dcde29..becf415b8b 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -16276,6 +16276,12 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm, goto endjob; if (mode == BLOCK_JOB_ABORT) { + if (async && !(flags & VIR_DOMAIN_BLOCK_JOB_ABORT_ASYNC)) { + /* prepare state for event delivery */ + disk->blockJobStatus = -1; + disk->blockJobSync = true; + } + if ((flags & VIR_DOMAIN_BLOCK_JOB_ABORT_PIVOT) && !(async && disk->mirror)) { virReportError(VIR_ERR_OPERATION_INVALID, @@ -16389,37 +16395,24 @@ qemuDomainBlockJobImpl(virDomainObjPtr vm, status); event2 = virDomainEventBlockJob2NewFromObj(vm, disk->dst, type, status); - } else if (!(flags & VIR_DOMAIN_BLOCK_JOB_ABORT_ASYNC)) { + } else if (disk->blockJobSync) { /* XXX If the event reports failure, we should reflect * that back into the return status of this API call. */ - while (1) { - /* Poll every 50ms */ - static struct timespec ts = { - .tv_sec = 0, - .tv_nsec = 50 * 1000 * 1000ull }; - virDomainBlockJobInfo dummy; - qemuDomainObjEnterMonitor(driver, vm); - ret = qemuMonitorBlockJobInfo(priv->mon, device, &dummy, NULL); - if (qemuDomainObjExitMonitor(driver, vm) < 0) - ret = -1; - - if (ret <= 0) - break; - - virObjectUnlock(vm); - - nanosleep(&ts, NULL); - - virObjectLock(vm); - - if (!virDomainObjIsActive(vm)) { - virReportError(VIR_ERR_OPERATION_INVALID, "%s", - _("domain is not running")); - ret = -1; - break; + while (disk->blockJobStatus == -1 && disk->blockJobSync) { + if (virCondWait(&disk->blockJobSyncCond, &vm->parent.lock) < 0) { + virReportSystemError(errno, "%s", + _("Unable to wait on block job sync " + "condition")); + disk->blockJobSync = false; + goto endjob; } } + + qemuBlockJobEventProcess(driver, vm, disk, + disk->blockJobType, + disk->blockJobStatus); + disk->blockJobSync = false; } } diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 79f763e324..2d86eb8411 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -1020,28 +1020,40 @@ qemuProcessHandleBlockJob(qemuMonitorPtr mon ATTRIBUTE_UNUSED, { virQEMUDriverPtr driver = opaque; struct qemuProcessEvent *processEvent = NULL; - char *data; + virDomainDiskDefPtr disk; + char *data = NULL; virObjectLock(vm); VIR_DEBUG("Block job for device %s (domain: %p,%s) type %d status %d", diskAlias, vm, vm->def->name, type, status); - if (VIR_ALLOC(processEvent) < 0) + if (!(disk = qemuProcessFindDomainDiskByAlias(vm, diskAlias))) goto error; - processEvent->eventType = QEMU_PROCESS_EVENT_BLOCK_JOB; - if (VIR_STRDUP(data, diskAlias) < 0) - goto error; - processEvent->data = data; - processEvent->vm = vm; - processEvent->action = type; - processEvent->status = status; + if (disk->blockJobSync) { + disk->blockJobType = type; + disk->blockJobStatus = status; + /* We have an SYNC API waiting for this event, dispatch it back */ + virCondSignal(&disk->blockJobSyncCond); + } else { + /* there is no waiting SYNC API, dispatch the update to a thread */ + if (VIR_ALLOC(processEvent) < 0) + goto error; - virObjectRef(vm); - if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) { - ignore_value(virObjectUnref(vm)); - goto error; + processEvent->eventType = QEMU_PROCESS_EVENT_BLOCK_JOB; + if (VIR_STRDUP(data, diskAlias) < 0) + goto error; + processEvent->data = data; + processEvent->vm = vm; + processEvent->action = type; + processEvent->status = status; + + virObjectRef(vm); + if (virThreadPoolSendJob(driver->workerPool, 0, processEvent) < 0) { + ignore_value(virObjectUnref(vm)); + goto error; + } } cleanup: