Re: [libvirt] [PATCH v3 11/18] snapshot: Add virDomainSnapshotObjListParse

Add a new function to make it possible to parse a list of snapshots at once. This is a counterpart to an earlier patch making it possible to produce all snapshots in a single XML string, and intentionally parses the same top-level element <snapshots> with an optional attribute current='name'. Note that since we know we started with no relations at all, and since checking parent relationships per-snapshot is not viable as we don't control which order the snapshots appear in, that we are fine with doing a final pass to update all parent/child relationships among the definitions. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- src/conf/snapshot_conf.h | 7 +++ src/conf/snapshot_conf.c | 111 +++++++++++++++++++++++++++++++++++++++ src/libvirt_private.syms | 1 + 3 files changed, 119 insertions(+) diff --git a/src/conf/snapshot_conf.h b/src/conf/snapshot_conf.h index 69a7750b0b..f8af991907 100644 --- a/src/conf/snapshot_conf.h +++ b/src/conf/snapshot_conf.h @@ -132,6 +132,13 @@ virDomainSnapshotDefPtr virDomainSnapshotDefParseNode(xmlDocPtr xml, virCapsPtr caps, virDomainXMLOptionPtr xmlopt, unsigned int flags); +int virDomainSnapshotObjListParse(const char *xmlStr, + const unsigned char *domain_uuid, + virDomainSnapshotObjListPtr snapshots, + virDomainSnapshotObjPtr *current_snap, + virCapsPtr caps, + virDomainXMLOptionPtr xmlopt, + unsigned int flags); void virDomainSnapshotDefFree(virDomainSnapshotDefPtr def); char *virDomainSnapshotDefFormat(const char *uuidstr, virDomainSnapshotDefPtr def, diff --git a/src/conf/snapshot_conf.c b/src/conf/snapshot_conf.c index a5b05eadf4..52742d82d6 100644 --- a/src/conf/snapshot_conf.c +++ b/src/conf/snapshot_conf.c @@ -507,6 +507,117 @@ virDomainSnapshotRedefineValidate(virDomainSnapshotDefPtr def, } +/* Parse a <snapshots> XML entry into snapshots, which must start empty. + * Any <domain> sub-elements of a <domainsnapshot> must match domain_uuid. + */ +int +virDomainSnapshotObjListParse(const char *xmlStr, + const unsigned char *domain_uuid, + virDomainSnapshotObjListPtr snapshots, + virDomainSnapshotObjPtr *current_snap, + virCapsPtr caps, + virDomainXMLOptionPtr xmlopt, + unsigned int flags) +{ + int ret = -1; + xmlDocPtr xml; + xmlNodePtr root; + xmlXPathContextPtr ctxt = NULL; + int n; + size_t i; + int keepBlanksDefault = xmlKeepBlanksDefault(0); + VIR_AUTOFREE(xmlNodePtr *) nodes = NULL; + VIR_AUTOFREE(char *) current = NULL; + + if (!(flags & VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE) || + (flags & VIR_DOMAIN_SNAPSHOT_PARSE_INTERNAL)) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("incorrect flags for bulk parse")); + return -1; + } + if (snapshots->metaroot.nchildren || *current_snap) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("bulk define of snapshots only possible with " + "no existing snapshot")); + return -1; + } + + if (!(xml = virXMLParse(NULL, xmlStr, _("(domain_snapshot)")))) + goto cleanup;

+ + root = xmlDocGetRootElement(xml); + if (!virXMLNodeNameEqual(root, "snapshots")) { + virReportError(VIR_ERR_XML_ERROR, + _("unexpected root element <%s>, " + "expecting <snapshots>"), root->name); + goto cleanup; + } + ctxt = xmlXPathNewContext(xml); + if (ctxt == NULL) { + virReportOOMError(); + goto cleanup; + } + ctxt->node = root; + current = virXMLPropString(root, "current"); + + if ((n = virXPathNodeSet("./domainsnapshot", ctxt, &nodes)) < 0) + goto cleanup; + if (!n) { + virReportError(VIR_ERR_XML_ERROR, "%s", + _("expected at least one <domainsnapshot> child")); + goto cleanup; + } + + for (i = 0; i < n; i++) { + virDomainSnapshotDefPtr def; + virDomainSnapshotObjPtr snap; + + def = virDomainSnapshotDefParseNode(xml, nodes[i], caps, xmlopt, flags); + if (!def) + goto cleanup; + if (!(snap = virDomainSnapshotAssignDef(snapshots, def))) { + virDomainSnapshotDefFree(def); + goto cleanup; + } + if (virDomainSnapshotRedefineValidate(def, domain_uuid, NULL, NULL, + flags) < 0) + goto cleanup; + } + + if (virDomainSnapshotUpdateRelations(snapshots) < 0) { + virReportError(VIR_ERR_XML_ERROR, "%s", + _("<snapshots> contains inconsistent parent-child " + "relationships")); + goto cleanup; + } + + if (current) { + if (!(*current_snap = virDomainSnapshotFindByName(snapshots, + current))) { + virReportError(VIR_ERR_NO_DOMAIN_SNAPSHOT, + _("no snapshot matching current='%s'"), current); + goto cleanup; + } + (*current_snap)->def->current = true; + } + + ret = 0; + cleanup: + if (ret < 0) { + /* There were no snapshots before this call; so on error, just + * blindly delete anything created before the failure. */ + virHashRemoveAll(snapshots->objs); + snapshots->metaroot.nchildren = 0; + snapshots->metaroot.first_child = NULL; + } + VIR_FREE(current);

+ xmlXPathFreeContext(ctxt); + xmlFreeDoc(xml); + xmlKeepBlanksDefault(keepBlanksDefault); + return ret; +} + + /** * virDomainSnapshotDefAssignExternalNames: * @def: snapshot def object diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index 35e0c6d9dc..395e1f8764 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -899,6 +899,7 @@ virDomainSnapshotObjListFree; virDomainSnapshotObjListGetNames; virDomainSnapshotObjListNew; virDomainSnapshotObjListNum; +virDomainSnapshotObjListParse; virDomainSnapshotObjListRemove; virDomainSnapshotRedefinePrep; virDomainSnapshotStateTypeFromString;