Re: [libvirt] [PATCH v8 11/21] backup: Parse and output backup XML

Accept XML describing a generic block job, and output it again as needed. This may still need a few tweaks to match the documented XML and RNG schema. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- src/conf/backup_conf.h | 97 +++++++ src/conf/virconftypes.h | 3 + src/conf/Makefile.inc.am | 2 + src/conf/backup_conf.c | 538 +++++++++++++++++++++++++++++++++++++++ src/libvirt_private.syms | 8 +- 5 files changed, 647 insertions(+), 1 deletion(-) create mode 100644 src/conf/backup_conf.h create mode 100644 src/conf/backup_conf.c

diff --git a/src/conf/backup_conf.h b/src/conf/backup_conf.h new file mode 100644 index 0000000000..74edb601f8 --- /dev/null +++ b/src/conf/backup_conf.h @@ -0,0 +1,97 @@ +/* + * backup_conf.h: domain backup XML processing + * (based on domain_conf.h) + * + * Copyright (C) 2006-2019 Red Hat, Inc. + * Copyright (C) 2006-2008 Daniel P. Berrange + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + */ + +#ifndef LIBVIRT_BACKUP_CONF_H +# define LIBVIRT_BACKUP_CONF_H + +# include "internal.h" +# include "domain_conf.h" +# include "moment_conf.h" +# include "virenum.h" + +/* Items related to incremental backup state */ + +typedef enum { + VIR_DOMAIN_BACKUP_TYPE_DEFAULT = 0, + VIR_DOMAIN_BACKUP_TYPE_PUSH, + VIR_DOMAIN_BACKUP_TYPE_PULL, + + VIR_DOMAIN_BACKUP_TYPE_LAST +} virDomainBackupType; + +typedef enum { + VIR_DOMAIN_BACKUP_DISK_STATE_DEFAULT = 0, /* Initial */ + VIR_DOMAIN_BACKUP_DISK_STATE_CREATED, /* File created */ + VIR_DOMAIN_BACKUP_DISK_STATE_LABEL, /* Security labels applied */ + VIR_DOMAIN_BACKUP_DISK_STATE_READY, /* Handed to guest */ + VIR_DOMAIN_BACKUP_DISK_STATE_BITMAP, /* Associated temp bitmap created */ + VIR_DOMAIN_BACKUP_DISK_STATE_EXPORT, /* NBD export created */ + VIR_DOMAIN_BACKUP_DISK_STATE_COMPLETE, /* Push job finished */

+} virDomainBackupDiskState; + +/* Stores disk-backup information */ +typedef struct _virDomainBackupDiskDef virDomainBackupDiskDef; +typedef virDomainBackupDiskDef *virDomainBackupDiskDefPtr; +struct _virDomainBackupDiskDef { + char *name; /* name matching the <target dev='...' of the domain */ + int idx; /* index within checkpoint->dom->disks that matches name */ + + /* details of target for push-mode, or of the scratch file for pull-mode */ + virStorageSourcePtr store; + int state; /* virDomainBackupDiskState, not stored in XML */ +}; + +/* Stores the complete backup metadata */ +typedef struct _virDomainBackupDef virDomainBackupDef; +typedef virDomainBackupDef *virDomainBackupDefPtr; +struct _virDomainBackupDef { + /* Public XML. */ + int type; /* virDomainBackupType */ + int id; + char *incremental; + virStorageNetHostDefPtr server; /* only when type == PULL */ + + size_t ndisks; /* should not exceed dom->ndisks */ + virDomainBackupDiskDef *disks; +}; + +VIR_ENUM_DECL(virDomainBackup); + +typedef enum { + VIR_DOMAIN_BACKUP_PARSE_INTERNAL = 1 << 0, +} virDomainBackupParseFlags; + +virDomainBackupDefPtr virDomainBackupDefParseString(const char *xmlStr, + virDomainXMLOptionPtr xmlopt, + unsigned int flags); +virDomainBackupDefPtr virDomainBackupDefParseNode(xmlDocPtr xml, + xmlNodePtr root, + virDomainXMLOptionPtr xmlopt, + unsigned int flags); +void virDomainBackupDefFree(virDomainBackupDefPtr def); +int virDomainBackupDefFormat(virBufferPtr buf, + virDomainBackupDefPtr def, + bool internal); +int virDomainBackupAlignDisks(virDomainBackupDefPtr backup, + virDomainDefPtr dom, const char *suffix);

+ +#endif /* LIBVIRT_BACKUP_CONF_H */

diff --git a/src/conf/backup_conf.c b/src/conf/backup_conf.c new file mode 100644 index 0000000000..723d6bad4b --- /dev/null +++ b/src/conf/backup_conf.c @@ -0,0 +1,538 @@ +/* + * backup_conf.c: domain backup XML processing + * + * Copyright (C) 2006-2019 Red Hat, Inc. + * Copyright (C) 2006-2008 Daniel P. Berrange + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library. If not, see + * <http://www.gnu.org/licenses/>;. + */ + +#include <config.h> + +#include "internal.h" +#include "virbitmap.h" +#include "virbuffer.h" +#include "datatypes.h" +#include "domain_conf.h" +#include "virlog.h" +#include "viralloc.h" +#include "backup_conf.h" +#include "virstoragefile.h" +#include "viruuid.h" +#include "virfile.h" +#include "virerror.h" +#include "virxml.h" +#include "virstring.h" + +#define VIR_FROM_THIS VIR_FROM_DOMAIN + +VIR_LOG_INIT("conf.backup_conf"); + +VIR_ENUM_IMPL(virDomainBackup, + VIR_DOMAIN_BACKUP_TYPE_LAST, + "default", "push", "pull"); + +static void +virDomainBackupDiskDefClear(virDomainBackupDiskDefPtr disk) +{ + VIR_FREE(disk->name); + virStorageSourceClear(disk->store);

+ disk->store = NULL; +} + +void +virDomainBackupDefFree(virDomainBackupDefPtr def) +{ + size_t i; + + if (!def) + return; + + VIR_FREE(def->incremental); + virStorageNetHostDefFree(1, def->server); + for (i = 0; i < def->ndisks; i++) + virDomainBackupDiskDefClear(&def->disks[i]); + VIR_FREE(def->disks); + VIR_FREE(def); +} + +static int +virDomainBackupDiskDefParseXML(xmlNodePtr node, + xmlXPathContextPtr ctxt, + virDomainBackupDiskDefPtr def, + bool push, bool internal, + virDomainXMLOptionPtr xmlopt) +{ + int ret = -1; + // char *backup = NULL; /* backup="yes|no"? */ + char *type = NULL; + char *driver = NULL; + xmlNodePtr cur; + xmlNodePtr saved = ctxt->node; + + ctxt->node = node; + + if (VIR_ALLOC(def->store) < 0)

+ goto cleanup; + + def->name = virXMLPropString(node, "name"); + if (!def->name) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("missing name from disk backup element")); + goto cleanup; + } + + /* Needed? A way for users to list a disk and explicitly mark it + * as not participating, and then output shows all disks rather + * than just active disks */ +#if 0 + backup = virXMLPropString(node, "backup"); + if (backup) { + def->type = virDomainCheckpointTypeFromString(checkpoint); + if (def->type <= 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("unknown disk checkpoint setting '%s'"), + checkpoint); + goto cleanup; + } + } +#endif + + if ((type = virXMLPropString(node, "type"))) { + if ((def->store->type = virStorageTypeFromString(type)) <= 0 || + def->store->type == VIR_STORAGE_TYPE_VOLUME || + def->store->type == VIR_STORAGE_TYPE_DIR) { + virReportError(VIR_ERR_XML_ERROR, + _("unknown disk backup type '%s'"), type); + goto cleanup; + } + } else { + def->store->type = VIR_STORAGE_TYPE_FILE; + } + + if ((cur = virXPathNode(push ? "./target" : "./scratch", ctxt)) && + virDomainStorageSourceParse(cur, ctxt, def->store, 0, xmlopt) < 0) + goto cleanup; + + if (internal) { + int detected; + if (virXPathInt("string(./node/@detected)", ctxt, &detected) < 0) + goto cleanup; + def->store->detected = detected; + def->store->nodeformat = virXPathString("string(./node)", ctxt); + } + + if ((driver = virXPathString("string(./driver/@type)", ctxt))) { + def->store->format = virStorageFileFormatTypeFromString(driver); + if (def->store->format <= 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("unknown disk backup driver '%s'"), driver); + goto cleanup; + } else if (!push && def->store->format != VIR_STORAGE_FILE_QCOW2) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("pull mode requires qcow2 driver, not '%s'"), + driver); + goto cleanup; + } + } + + /* validate that the passed path is absolute */ + if (virStorageSourceIsRelative(def->store)) { + virReportError(VIR_ERR_XML_ERROR, + _("disk backup image path '%s' must be absolute"), + def->store->path); + goto cleanup; + } + + ret = 0; + cleanup: + ctxt->node = saved; + + VIR_FREE(driver); +// VIR_FREE(backup); + VIR_FREE(type); + if (ret < 0) + virDomainBackupDiskDefClear(def); + return ret; +} + +static virDomainBackupDefPtr +virDomainBackupDefParse(xmlXPathContextPtr ctxt, + virDomainXMLOptionPtr xmlopt, + unsigned int flags) +{ + virDomainBackupDefPtr def = NULL; + virDomainBackupDefPtr ret = NULL; + xmlNodePtr *nodes = NULL; + xmlNodePtr node = NULL; + char *mode = NULL; + bool push; + size_t i; + int n; + + if (VIR_ALLOC(def) < 0) + goto cleanup; + + mode = virXMLPropString(ctxt->node, "mode"); + if (mode) { + def->type = virDomainBackupTypeFromString(mode); + if (def->type <= 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("unknown backup mode '%s'"), mode); + goto cleanup; + } + } else { + def->type = VIR_DOMAIN_BACKUP_TYPE_PUSH; + } + push = def->type == VIR_DOMAIN_BACKUP_TYPE_PUSH; + + if (flags & VIR_DOMAIN_BACKUP_PARSE_INTERNAL) { + char *tmp = virXMLPropString(ctxt->node, "id"); + if (tmp && virStrToLong_i(tmp, NULL, 10, &def->id) < 0) { + virReportError(VIR_ERR_XML_ERROR, + _("invalid 'id' value '%s'"), tmp); + VIR_FREE(tmp); + goto cleanup; + } + VIR_FREE(tmp); + } + + def->incremental = virXPathString("string(./incremental)", ctxt); + + node = virXPathNode("./server", ctxt); + if (node) { + if (def->type != VIR_DOMAIN_BACKUP_TYPE_PULL) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("use of <server> requires pull mode backup")); + goto cleanup; + } + if (VIR_ALLOC(def->server) < 0) + goto cleanup; + if (virDomainStorageNetworkParseHost(node, def->server) < 0) + goto cleanup; + if (def->server->transport == VIR_STORAGE_NET_HOST_TRANS_RDMA) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("transport rdma is not supported for <server>")); + goto cleanup; + } + } + + if ((n = virXPathNodeSet("./disks/*", ctxt, &nodes)) < 0) + goto cleanup; + if (n && VIR_ALLOC_N(def->disks, n) < 0) + goto cleanup; + def->ndisks = n; + for (i = 0; i < def->ndisks; i++) { + if (virDomainBackupDiskDefParseXML(nodes[i], ctxt, + &def->disks[i], push, + flags & VIR_DOMAIN_BACKUP_PARSE_INTERNAL, + xmlopt) < 0) + goto cleanup; + } + VIR_FREE(nodes); + + VIR_STEAL_PTR(ret, def); + + cleanup: + VIR_FREE(mode); + VIR_FREE(nodes); + virDomainBackupDefFree(def); + + return ret; +}

+static int +virDomainBackupDiskDefFormat(virBufferPtr buf, + virDomainBackupDiskDefPtr disk, + bool push, bool internal) +{ + int type = disk->store->type; + virBuffer attrBuf = VIR_BUFFER_INITIALIZER; + virBuffer childBuf = VIR_BUFFER_INITIALIZER; + int ret = -1; + + if (!disk->name) + return 0; + + virBufferEscapeString(buf, "<disk name='%s'", disk->name); + /* TODO: per-disk backup=off? */ + + virBufferAsprintf(buf, " type='%s'>\n", virStorageTypeToString(type)); + virBufferAdjustIndent(buf, 2); + + if (disk->store->format > 0) + virBufferEscapeString(buf, "<driver type='%s'/>\n", + virStorageFileFormatTypeToString(disk->store->format)); + /* TODO: should node names be part of storage file xml, rather + * than a one-off hack for qemu? */

+ if (internal) { + virBufferEscapeString(buf, "<node detected='%s'", + disk->store->detected ? "1" : "0");

+ virBufferEscapeString(buf, ">%s</node>\n", disk->store->nodeformat);

+ } + + if (virDomainDiskSourceFormat(buf, disk->store, push ? "target" : "scratch", + 0, false, 0, NULL) < 0) + goto cleanup; + virBufferAdjustIndent(buf, -2); + virBufferAddLit(buf, "</disk>\n"); + + ret = 0; + + cleanup: + virBufferFreeAndReset(&attrBuf); + virBufferFreeAndReset(&childBuf); + return ret; +} + +int +virDomainBackupDefFormat(virBufferPtr buf, virDomainBackupDefPtr def, + bool internal) +{ + size_t i; + + virBufferAsprintf(buf, "<domainbackup mode='%s'", + virDomainBackupTypeToString(def->type)); + if (def->id) + virBufferAsprintf(buf, " id='%d'", def->id); + virBufferAddLit(buf, ">\n"); + virBufferAdjustIndent(buf, 2); + + virBufferEscapeString(buf, "<incremental>%s</incremental>\n", + def->incremental); + if (def->server) { + virBufferAsprintf(buf, "<server transport='%s'", + virStorageNetHostTransportTypeToString(def->server->transport)); + virBufferEscapeString(buf, " name='%s'", def->server->name); + if (def->server->port) + virBufferAsprintf(buf, " port='%u'", def->server->port); + virBufferEscapeString(buf, " socket='%s'", def->server->socket); + virBufferAddLit(buf, "/>\n"); + } + + if (def->ndisks) { + virBufferAddLit(buf, "<disks>\n"); + virBufferAdjustIndent(buf, 2); + for (i = 0; i < def->ndisks; i++) { + if (!def->disks[i].store) + continue; + if (virDomainBackupDiskDefFormat(buf, &def->disks[i], + def->type == VIR_DOMAIN_BACKUP_TYPE_PUSH, + internal) < 0) + return -1; + } + virBufferAdjustIndent(buf, -2); + virBufferAddLit(buf, "</disks>\n"); + } + + virBufferAdjustIndent(buf, -2); + virBufferAddLit(buf, "</domainbackup>\n"); + + return virBufferCheckError(buf); +} + + +static int +virDomainBackupCompareDiskIndex(const void *a, const void *b) +{ + const virDomainBackupDiskDef *diska = a; + const virDomainBackupDiskDef *diskb = b; + + /* Integer overflow shouldn't be a problem here. */ + return diska->idx - diskb->idx; +} + +static int +virDomainBackupDefAssignStore(virDomainBackupDiskDefPtr disk, + virStorageSourcePtr src, + const char *suffix) +{ + int ret = -1; + + if (virStorageSourceIsEmpty(src)) { + if (disk->store) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("disk '%s' has no media"), disk->name); + goto cleanup; + } + } else if (src->readonly && disk->store) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("backup of readonly disk '%s' makes no sense"), + disk->name); + goto cleanup; + } else if (!disk->store) { + if (virStorageSourceGetActualType(src) == VIR_STORAGE_TYPE_FILE) { + if (VIR_ALLOC(disk->store) < 0)

+ goto cleanup; + disk->store->type = VIR_STORAGE_TYPE_FILE; + if (virAsprintf(&disk->store->path, "%s.%s", src->path, + suffix) < 0)

+ goto cleanup; + disk->store->detected = true;

+ } else { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("refusing to generate file name for disk '%s'"), + disk->name); + goto cleanup; + } + } + ret = 0; + cleanup:

+ return ret; +} + +/* Align def->disks to domain. Sort the list of def->disks, + * generating storage names using suffix as needed. Convert paths to + * disk targets for uniformity. Issue an error and return -1 if any + * def->disks[n]->name appears more than once or does not map to + * dom->disks. */ +int +virDomainBackupAlignDisks(virDomainBackupDefPtr def, virDomainDefPtr dom, + const char *suffix) +{ + int ret = -1; + virBitmapPtr map = NULL; + size_t i; + int ndisks; + bool alloc_all = false; + + if (def->ndisks > dom->ndisks) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("too many disk backup requests for domain")); + goto cleanup; + } + + /* Unlikely to have a guest without disks but technically possible. */ + if (!dom->ndisks) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", + _("domain must have at least one disk to perform " + "backups")); + goto cleanup; + } + + if (!(map = virBitmapNew(dom->ndisks))) + goto cleanup; + + /* Double check requested disks. */ + for (i = 0; i < def->ndisks; i++) { + virDomainBackupDiskDefPtr disk = &def->disks[i]; + int idx = virDomainDiskIndexByName(dom, disk->name, false); + + if (idx < 0) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("no disk named '%s'"), disk->name); + goto cleanup; + } + + if (virBitmapIsBitSet(map, idx)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("disk '%s' specified twice"), + disk->name); + goto cleanup; + } + ignore_value(virBitmapSetBit(map, idx)); + disk->idx = idx; + + if (STRNEQ(disk->name, dom->disks[idx]->dst)) { + VIR_FREE(disk->name); + if (VIR_STRDUP(disk->name, dom->disks[idx]->dst) < 0) + goto cleanup; + } + if (disk->store && !disk->store->path) { + virStorageSourceClear(disk->store); + disk->store = NULL; + } + if (virDomainBackupDefAssignStore(disk, dom->disks[i]->src, suffix) < 0) + goto cleanup; + } + + /* Provide fillers for all remaining disks, for easier iteration. */ + if (!def->ndisks)

+ alloc_all = true; + ndisks = def->ndisks; + if (VIR_EXPAND_N(def->disks, def->ndisks, + dom->ndisks - def->ndisks) < 0) + goto cleanup; + + for (i = 0; i < dom->ndisks; i++) { + virDomainBackupDiskDefPtr disk; + + if (virBitmapIsBitSet(map, i)) + continue; + disk = &def->disks[ndisks++]; + if (VIR_STRDUP(disk->name, dom->disks[i]->dst) < 0) + goto cleanup; + disk->idx = i; + if (alloc_all && + virDomainBackupDefAssignStore(disk, dom->disks[i]->src, suffix) < 0) + goto cleanup; + } + + qsort(&def->disks[0], def->ndisks, sizeof(def->disks[0]), + virDomainBackupCompareDiskIndex); + + ret = 0; + + cleanup: + virBitmapFree(map); + return ret; +}