Re: [libvirt] [PATCH v9 11/13] backup: qemu: Implement metadata tracking for checkpoint APIs

A lot of this work heavily copies from the existing snapshot APIs. The interaction with qemu during create/delete still needs to be implemented, but this takes care of all the libvirt metadata (saving and restoring XML, and tracking the relations between multiple checkpoints). Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- src/qemu/qemu_block.h | 3 + src/qemu/qemu_conf.h | 2 + src/qemu/qemu_domain.h | 15 + src/qemu/qemu_block.c | 12 + src/qemu/qemu_conf.c | 5 + src/qemu/qemu_domain.c | 133 ++++++++ src/qemu/qemu_driver.c | 675 +++++++++++++++++++++++++++++++++++++++++ 7 files changed, 845 insertions(+)

diff --git a/src/qemu/qemu_block.c b/src/qemu/qemu_block.c index 0a6522577d..5f5e330479 100644 --- a/src/qemu/qemu_block.c +++ b/src/qemu/qemu_block.c @@ -1821,3 +1821,15 @@ qemuBlockStorageGetCopyOnReadProps(virDomainDiskDefPtr disk) return ret; } + +const char * +qemuBlockNodeLookup(virDomainObjPtr vm, const char *disk)

+{ + size_t i; + + for (i = 0; i < vm->def->ndisks; i++) { + if (STREQ(vm->def->disks[i]->dst, disk)) + return vm->def->disks[i]->src->nodeformat; + } + return NULL; +}

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 97f3d7f786..702a715902 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c

@@ -221,6 +222,40 @@ qemuSnapObjFromSnapshot(virDomainObjPtr vm, return qemuSnapObjFromName(vm, snapshot->name); } +/* Looks up the domain object from checkpoint and unlocks the + * driver. The returned domain object is locked and ref'd and the + * caller must call virDomainObjEndAPI() on it. */ +static virDomainObjPtr +qemuDomObjFromCheckpoint(virDomainCheckpointPtr checkpoint) +{ + return qemuDomObjFromDomain(checkpoint->domain); +} + + +/* Looks up checkpoint object from VM and name */ +static virDomainMomentObjPtr +qemuCheckObjFromName(virDomainObjPtr vm, + const char *name) +{ + virDomainMomentObjPtr chk = NULL; + chk = virDomainCheckpointFindByName(vm->checkpoints, name); + if (!chk) + virReportError(VIR_ERR_NO_DOMAIN_CHECKPOINT, + _("no domain checkpoint with matching name '%s'"), + name); + + return chk; +} + + +/* Looks up checkpoint object from VM and checkpointPtr */ +static virDomainMomentObjPtr +qemuCheckObjFromCheckpoint(virDomainObjPtr vm, + virDomainCheckpointPtr checkpoint)

+{ + return qemuCheckObjFromName(vm, checkpoint->name); +} + static int qemuAutostartDomain(virDomainObjPtr vm, void *opaque) @@ -524,6 +559,123 @@ qemuDomainSnapshotLoad(virDomainObjPtr vm, } +static int +qemuDomainCheckpointLoad(virDomainObjPtr vm, + void *data) +{ + char *baseDir = (char *)data; + char *chkDir = NULL; + DIR *dir = NULL; + struct dirent *entry; + char *xmlStr; + char *fullpath; + virDomainCheckpointDefPtr def = NULL; + virDomainMomentObjPtr chk = NULL; + virDomainMomentObjPtr current = NULL; + bool cur; + unsigned int flags = VIR_DOMAIN_CHECKPOINT_PARSE_REDEFINE; + int ret = -1; + virCapsPtr caps = NULL; + int direrr; + + virObjectLock(vm); + if (virAsprintf(&chkDir, "%s/%s", baseDir, vm->def->name) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Failed to allocate memory for " + "checkpoint directory for domain %s"), + vm->def->name); + goto cleanup; + } + + if (!(caps = virQEMUDriverGetCapabilities(qemu_driver, false))) + goto cleanup; + + VIR_INFO("Scanning for checkpoints for domain %s in %s", vm->def->name, + chkDir); + + if (virDirOpenIfExists(&dir, chkDir) <= 0) + goto cleanup; + + while ((direrr = virDirRead(dir, &entry, NULL)) > 0) { + /* NB: ignoring errors, so one malformed config doesn't + kill the whole process */ + VIR_INFO("Loading checkpoint file '%s'", entry->d_name); + + if (virAsprintf(&fullpath, "%s/%s", chkDir, entry->d_name) < 0) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Failed to allocate memory for path")); + continue; + } + + if (virFileReadAll(fullpath, 1024*1024*1, &xmlStr) < 0) { + /* Nothing we can do here, skip this one */ + virReportSystemError(errno, + _("Failed to read checkpoint file %s"), + fullpath); + VIR_FREE(fullpath); + continue; + } + + def = virDomainCheckpointDefParseString(xmlStr, caps, + qemu_driver->xmlopt, &cur, + flags); + if (!def || virDomainCheckpointAlignDisks(def) < 0) { + /* Nothing we can do here, skip this one */ + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Failed to parse checkpoint XML from file '%s'"), + fullpath); + VIR_FREE(fullpath); + VIR_FREE(xmlStr);

+ continue; + } + + chk = virDomainCheckpointAssignDef(vm->checkpoints, def); + if (chk == NULL) { + virObjectUnref(def); + } else if (cur) { + if (current) + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Too many checkpoints claiming to be current for domain %s"), + vm->def->name); + current = chk; + } + + VIR_FREE(fullpath); + VIR_FREE(xmlStr); + } + if (direrr < 0) + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Failed to fully read directory %s"), + chkDir); + + virDomainCheckpointSetCurrent(vm->checkpoints, current); + + if (virDomainCheckpointUpdateRelations(vm->checkpoints) < 0) + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Checkpoints have inconsistent relations for domain %s"), + vm->def->name); + + /* FIXME: qemu keeps internal track of bitmaps, which form the + * basis for checkpoints; it would be nice if we could update our + * internal state to reflect that information automatically. But + * qemu 3.0 did not have access to this via qemu-img for offline + * images (you have to use QMP commands on a running guest), and + * it also does not track <parent> relations which we find + * important in our metadata. + */

+ + virResetLastError(); + + ret = 0; + cleanup: + VIR_DIR_CLOSE(dir); + VIR_FREE(chkDir); + virObjectUnref(caps); + virObjectUnlock(vm); + return ret; +} + + static int qemuDomainNetsRestart(virDomainObjPtr vm, void *data ATTRIBUTE_UNUSED)

@@ -7710,6 +7878,7 @@ qemuDomainUndefineFlags(virDomainPtr dom, if (qemuDomainSnapshotDiscardAllMetadata(driver, vm) < 0) goto endjob; } + /* TODO: Restrict deletion if checkpoints exist? */

name = qemuDomainManagedSavePath(driver, vm); if (name == NULL)

@@ -16728,6 +16903,492 @@ qemuDomainSnapshotDelete(virDomainSnapshotPtr snapshot, return ret; } + +/* Called prior to job lock */ +static virDomainCheckpointDefPtr +qemuDomainCheckpointDefParseString(virQEMUDriverPtr driver, virCapsPtr caps, + const char *xmlDesc, bool *current, + unsigned int flags) +{ + virDomainCheckpointDefPtr ret = NULL; + unsigned int parse_flags = 0; + VIR_AUTOUNREF(virDomainCheckpointDefPtr) def = NULL; + + if (flags & VIR_DOMAIN_CHECKPOINT_CREATE_REDEFINE) + parse_flags |= VIR_DOMAIN_CHECKPOINT_PARSE_REDEFINE; + if (!(def = virDomainCheckpointDefParseString(xmlDesc, caps, driver->xmlopt, + current, parse_flags))) + return NULL; + + /* reject checkpoint names containing slashes or starting with dot as + * checkpoint definitions are saved in files named by the checkpoint name */ + if (!(flags & VIR_DOMAIN_CHECKPOINT_CREATE_NO_METADATA)) { + if (strchr(def->parent.name, '/')) { + virReportError(VIR_ERR_XML_DETAIL, + _("invalid checkpoint name '%s': " + "name can't contain '/'"), + def->parent.name);

+ return NULL; + } + + if (def->parent.name[0] == '.') { + virReportError(VIR_ERR_XML_DETAIL, + _("invalid checkpoint name '%s': " + "name can't start with '.'"), + def->parent.name); + return NULL; + } + } + + VIR_STEAL_PTR(ret, def); + return ret; +}

+static int +qemuDomainCheckpointPrepare(virQEMUDriverPtr driver, virCapsPtr caps, + virDomainObjPtr vm, + virDomainCheckpointDefPtr def) +{ + int ret = -1; + size_t i; + char *xml = NULL; + qemuDomainObjPrivatePtr priv = vm->privateData; + + /* Easiest way to clone inactive portion of vm->def is via + * conversion in and back out of xml. */ + if (!(xml = qemuDomainDefFormatLive(driver, vm->def, priv->origCPU, + true, true)) || + !(def->parent.dom = virDomainDefParseString(xml, caps, driver->xmlopt, NULL, + VIR_DOMAIN_DEF_PARSE_INACTIVE | + VIR_DOMAIN_DEF_PARSE_SKIP_VALIDATE))) + goto cleanup; + + if (virDomainCheckpointAlignDisks(def) < 0 || + qemuBlockNodeNamesDetect(driver, vm, QEMU_ASYNC_JOB_NONE) < 0)

+ goto cleanup; + + for (i = 0; i < def->ndisks; i++) { + virDomainCheckpointDiskDefPtr disk = &def->disks[i]; + + if (disk->type != VIR_DOMAIN_CHECKPOINT_TYPE_BITMAP) + continue; + + if (vm->def->disks[i]->src->format > 0 && + vm->def->disks[i]->src->format != VIR_STORAGE_FILE_QCOW2) {

+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("checkpoint for disk %s unsupported " + "for storage type %s"), + disk->name, + virStorageFileFormatTypeToString( + vm->def->disks[i]->src->format));