From: Peter Krempa <pkrempa@redhat.com> If the user wants to manually preserve state of the disk we need, apart from pausing the machine to quiesce all writes, also deactivate the block nodes of the device. This ensures that qemu writes out metadata (e.g. block dirty bitmaps) which are normally stored only in memory, thus allowing a consistent snapshot including the metadata. Signed-off-by: Peter Krempa <pkrempa@redhat.com> --- src/qemu/qemu_snapshot.c | 81 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 81 insertions(+) diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c index c988de37ca..5c12dca892 100644 --- a/src/qemu/qemu_snapshot.c +++ b/src/qemu/qemu_snapshot.c @@ -1552,6 +1552,83 @@ qemuSnapshotCreateActiveExternalDisks(virDomainObj *vm, } +static int +qemuSnapshotCreateActiveExternalDisksManual(virDomainObj *vm, + virDomainMomentObj *snap, + virDomainAsyncJob asyncJob) +{ + qemuDomainObjPrivate *priv = vm->privateData; + virDomainSnapshotDef *snapdef = virDomainSnapshotObjGetDef(snap); + g_autoptr(GPtrArray) nodenames = g_ptr_array_new(); + int ret = 0; + size_t i; + + if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_BLOCKDEV_SET_ACTIVE)) + return 0; + + for (i = 0; i < snapdef->ndisks; i++) { + virDomainDiskDef *domdisk = vm->def->disks[i]; + qemuDomainDiskPrivate *domdiskPriv = QEMU_DOMAIN_DISK_PRIVATE(domdisk); + virStorageSource *n; + + if (snapdef->disks[i].snapshot != VIR_DOMAIN_SNAPSHOT_LOCATION_MANUAL) + continue; + + if (domdiskPriv->nodeCopyOnRead) + g_ptr_array_add(nodenames, domdiskPriv->nodeCopyOnRead); + + if (domdisk->nthrottlefilters > 0) { + size_t j; + + for (j = 0; j < domdisk->nthrottlefilters; j++) { + g_ptr_array_add(nodenames, (void *) qemuBlockThrottleFilterGetNodename(domdisk->throttlefilters[j])); + } + } + + for (n = domdisk->src; virStorageSourceIsBacking(n); n = n->backingStore) { + const char *tmp; + + if ((tmp = qemuBlockStorageSourceGetFormatNodename(n))) + g_ptr_array_add(nodenames, (void *) tmp); + + if ((tmp = qemuBlockStorageSourceGetSliceNodename(n))) + g_ptr_array_add(nodenames, (void *) tmp); + + g_ptr_array_add(nodenames, (void *) qemuBlockStorageSourceGetStorageNodename(n)); + + if (n->dataFileStore) { + if ((tmp = qemuBlockStorageSourceGetFormatNodename(n->dataFileStore))) + g_ptr_array_add(nodenames, (void *) tmp); + + if ((tmp = qemuBlockStorageSourceGetSliceNodename(n->dataFileStore))) + g_ptr_array_add(nodenames, (void *) tmp); + + g_ptr_array_add(nodenames, (void *) qemuBlockStorageSourceGetStorageNodename(n->dataFileStore)); + } + } + } + + if (nodenames->len == 0) + return 0; + + if (qemuDomainObjEnterMonitorAsync(vm, asyncJob) < 0) + return -1; + + for (i = 0; i < nodenames->len; i++) { + const char *nodename = g_ptr_array_index(nodenames, i); + + if (qemuMonitorBlockdevSetActive(priv->mon, nodename, false) < 0) { + ret = -1; + break; + } + } + + qemuDomainObjExitMonitor(vm); + + return ret; +} + + static int qemuSnapshotCreateActiveExternal(virQEMUDriver *driver, virDomainObj *vm, @@ -1627,6 +1704,10 @@ qemuSnapshotCreateActiveExternal(virQEMUDriver *driver, } } + if (has_manual && + qemuSnapshotCreateActiveExternalDisksManual(vm, snap, VIR_ASYNC_JOB_SNAPSHOT) < 0) + goto cleanup; + /* We need to collect reply from 'query-named-block-nodes' prior to the * migration step as qemu deactivates bitmaps after migration so the result * would be wrong */ -- 2.51.0