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libvirt/src/conf/snapshot_conf.c
John Ferlan c028c71930 conf: Add error checking to virDomainSnapshotDiskDefFormat 
Commit id '43f2ccdc' called virDomainDiskSourceDefFormatInternal
rather than formatting the the disk source inline. However, it
did not handle the case where the helper failed. Over time the
helper has been renamed to virDomainDiskSourceFormat. Similar to
other consumers, if virDomainDiskSourceFormat fails, then the
formatting could be off, so it's better to fail than to continue
on with some possibly bad data. Alter the function and the caller
to check status and jump to error in that case.

Found by Coverity

Signed-off-by: John Ferlan <jferlan@redhat.com>
2018-04-19 14:23:39 -04:00

1374 lines
44 KiB
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/*
* snapshot_conf.c: domain snapshot XML processing
*
* Copyright (C) 2006-2014 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/>.
*
* Author: Eric Blake <eblake@redhat.com>
*/
#include <config.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <unistd.h>
#include "internal.h"
#include "virbitmap.h"
#include "virbuffer.h"
#include "count-one-bits.h"
#include "datatypes.h"
#include "domain_conf.h"
#include "virlog.h"
#include "viralloc.h"
#include "netdev_bandwidth_conf.h"
#include "netdev_vport_profile_conf.h"
#include "nwfilter_conf.h"
#include "secret_conf.h"
#include "snapshot_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_SNAPSHOT
VIR_LOG_INIT("conf.snapshot_conf");
VIR_ENUM_IMPL(virDomainSnapshotLocation, VIR_DOMAIN_SNAPSHOT_LOCATION_LAST,
"default",
"no",
"internal",
"external")
/* virDomainSnapshotState is really virDomainState plus one extra state */
VIR_ENUM_IMPL(virDomainSnapshotState, VIR_DOMAIN_SNAPSHOT_STATE_LAST,
"nostate",
"running",
"blocked",
"paused",
"shutdown",
"shutoff",
"crashed",
"pmsuspended",
"disk-snapshot")
struct _virDomainSnapshotObjList {
/* name string -> virDomainSnapshotObj mapping
* for O(1), lockless lookup-by-name */
virHashTable *objs;
virDomainSnapshotObj metaroot; /* Special parent of all root snapshots */
};
/* Snapshot Def functions */
static void
virDomainSnapshotDiskDefClear(virDomainSnapshotDiskDefPtr disk)
{
VIR_FREE(disk->name);
virStorageSourceFree(disk->src);
disk->src = NULL;
}
void virDomainSnapshotDefFree(virDomainSnapshotDefPtr def)
{
size_t i;
if (!def)
return;
VIR_FREE(def->name);
VIR_FREE(def->description);
VIR_FREE(def->parent);
VIR_FREE(def->file);
for (i = 0; i < def->ndisks; i++)
virDomainSnapshotDiskDefClear(&def->disks[i]);
VIR_FREE(def->disks);
virDomainDefFree(def->dom);
virObjectUnref(def->cookie);
VIR_FREE(def);
}
static int
virDomainSnapshotDiskDefParseXML(xmlNodePtr node,
xmlXPathContextPtr ctxt,
virDomainSnapshotDiskDefPtr def,
unsigned int flags,
virDomainXMLOptionPtr xmlopt)
{
int ret = -1;
char *snapshot = NULL;
char *type = NULL;
char *driver = NULL;
xmlNodePtr cur;
xmlNodePtr saved = ctxt->node;
ctxt->node = node;
if (VIR_ALLOC(def->src) < 0)
goto cleanup;
def->name = virXMLPropString(node, "name");
if (!def->name) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("missing name from disk snapshot element"));
goto cleanup;
}
snapshot = virXMLPropString(node, "snapshot");
if (snapshot) {
def->snapshot = virDomainSnapshotLocationTypeFromString(snapshot);
if (def->snapshot <= 0) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("unknown disk snapshot setting '%s'"),
snapshot);
goto cleanup;
}
}
if ((type = virXMLPropString(node, "type"))) {
if ((def->src->type = virStorageTypeFromString(type)) <= 0 ||
def->src->type == VIR_STORAGE_TYPE_VOLUME ||
def->src->type == VIR_STORAGE_TYPE_DIR) {
virReportError(VIR_ERR_XML_ERROR,
_("unknown disk snapshot type '%s'"), type);
goto cleanup;
}
} else {
def->src->type = VIR_STORAGE_TYPE_FILE;
}
if ((cur = virXPathNode("./source", ctxt)) &&
virDomainDiskSourceParse(cur, ctxt, def->src, flags, xmlopt) < 0)
goto cleanup;
if ((driver = virXPathString("string(./driver/@type)", ctxt))) {
def->src->format = virStorageFileFormatTypeFromString(driver);
if (def->src->format < VIR_STORAGE_FILE_BACKING) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
def->src->format <= 0
? _("unknown disk snapshot driver '%s'")
: _("disk format '%s' lacks backing file "
"support"),
driver);
goto cleanup;
}
}
/* validate that the passed path is absolute */
if (virStorageSourceIsRelative(def->src)) {
virReportError(VIR_ERR_XML_ERROR,
_("disk snapshot image path '%s' must be absolute"),
def->src->path);
goto cleanup;
}
if (!def->snapshot && (def->src->path || def->src->format))
def->snapshot = VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL;
ret = 0;
cleanup:
ctxt->node = saved;
VIR_FREE(driver);
VIR_FREE(snapshot);
VIR_FREE(type);
if (ret < 0)
virDomainSnapshotDiskDefClear(def);
return ret;
}
/* flags is bitwise-or of virDomainSnapshotParseFlags.
* If flags does not include VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE, then
* caps are ignored.
*/
static virDomainSnapshotDefPtr
virDomainSnapshotDefParse(xmlXPathContextPtr ctxt,
virCapsPtr caps,
virDomainXMLOptionPtr xmlopt,
unsigned int flags)
{
virDomainSnapshotDefPtr def = NULL;
virDomainSnapshotDefPtr ret = NULL;
xmlNodePtr *nodes = NULL;
size_t i;
int n;
char *creation = NULL, *state = NULL;
struct timeval tv;
int active;
char *tmp;
char *memorySnapshot = NULL;
char *memoryFile = NULL;
bool offline = !!(flags & VIR_DOMAIN_SNAPSHOT_PARSE_OFFLINE);
virSaveCookieCallbacksPtr saveCookie = virDomainXMLOptionGetSaveCookie(xmlopt);
if (VIR_ALLOC(def) < 0)
goto cleanup;
gettimeofday(&tv, NULL);
def->name = virXPathString("string(./name)", ctxt);
if (def->name == NULL) {
if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE) {
virReportError(VIR_ERR_XML_ERROR, "%s",
_("a redefined snapshot must have a name"));
goto cleanup;
}
if (virAsprintf(&def->name, "%lld", (long long)tv.tv_sec) < 0)
goto cleanup;
}
def->description = virXPathString("string(./description)", ctxt);
if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE) {
if (virXPathLongLong("string(./creationTime)", ctxt,
&def->creationTime) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("missing creationTime from existing snapshot"));
goto cleanup;
}
def->parent = virXPathString("string(./parent/name)", ctxt);
state = virXPathString("string(./state)", ctxt);
if (state == NULL) {
/* there was no state in an existing snapshot; this
* should never happen
*/
virReportError(VIR_ERR_XML_ERROR, "%s",
_("missing state from existing snapshot"));
goto cleanup;
}
def->state = virDomainSnapshotStateTypeFromString(state);
if (def->state < 0) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("Invalid state '%s' in domain snapshot XML"),
state);
goto cleanup;
}
offline = (def->state == VIR_DOMAIN_SHUTOFF ||
def->state == VIR_DOMAIN_DISK_SNAPSHOT);
/* Older snapshots were created with just <domain>/<uuid>, and
* lack domain/@type. In that case, leave dom NULL, and
* clients will have to decide between best effort
* initialization or outright failure. */
if ((tmp = virXPathString("string(./domain/@type)", ctxt))) {
int domainflags = VIR_DOMAIN_DEF_PARSE_INACTIVE |
VIR_DOMAIN_DEF_PARSE_SKIP_VALIDATE;
if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_INTERNAL)
domainflags |= VIR_DOMAIN_DEF_PARSE_SKIP_OSTYPE_CHECKS;
xmlNodePtr domainNode = virXPathNode("./domain", ctxt);
VIR_FREE(tmp);
if (!domainNode) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("missing domain in snapshot"));
goto cleanup;
}
def->dom = virDomainDefParseNode(ctxt->node->doc, domainNode,
caps, xmlopt, NULL, domainflags);
if (!def->dom)
goto cleanup;
} else {
VIR_WARN("parsing older snapshot that lacks domain");
}
} else {
def->creationTime = tv.tv_sec;
}
memorySnapshot = virXPathString("string(./memory/@snapshot)", ctxt);
memoryFile = virXPathString("string(./memory/@file)", ctxt);
if (memorySnapshot) {
def->memory = virDomainSnapshotLocationTypeFromString(memorySnapshot);
if (def->memory <= 0) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("unknown memory snapshot setting '%s'"),
memorySnapshot);
goto cleanup;
}
if (memoryFile &&
def->memory != VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL) {
virReportError(VIR_ERR_XML_ERROR,
_("memory filename '%s' requires external snapshot"),
memoryFile);
goto cleanup;
}
if (!memoryFile &&
def->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL) {
virReportError(VIR_ERR_XML_ERROR, "%s",
_("external memory snapshots require a filename"));
goto cleanup;
}
} else if (memoryFile) {
def->memory = VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL;
} else if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE) {
def->memory = (offline ?
VIR_DOMAIN_SNAPSHOT_LOCATION_NONE :
VIR_DOMAIN_SNAPSHOT_LOCATION_INTERNAL);
}
if (offline && def->memory &&
def->memory != VIR_DOMAIN_SNAPSHOT_LOCATION_NONE) {
virReportError(VIR_ERR_XML_ERROR, "%s",
_("memory state cannot be saved with offline or "
"disk-only snapshot"));
goto cleanup;
}
def->file = memoryFile;
memoryFile = NULL;
/* verify that memory path is absolute */
if (def->file && def->file[0] != '/') {
virReportError(VIR_ERR_XML_ERROR,
_("memory snapshot file path (%s) must be absolute"),
def->file);
goto cleanup;
}
if ((n = virXPathNodeSet("./disks/*", ctxt, &nodes)) < 0)
goto cleanup;
if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_DISKS) {
if (n && VIR_ALLOC_N(def->disks, n) < 0)
goto cleanup;
def->ndisks = n;
for (i = 0; i < def->ndisks; i++) {
if (virDomainSnapshotDiskDefParseXML(nodes[i], ctxt, &def->disks[i],
flags, xmlopt) < 0)
goto cleanup;
}
VIR_FREE(nodes);
} else if (n) {
virReportError(VIR_ERR_ARGUMENT_UNSUPPORTED, "%s",
_("unable to handle disk requests in snapshot"));
goto cleanup;
}
if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_INTERNAL) {
if (virXPathInt("string(./active)", ctxt, &active) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Could not find 'active' element"));
goto cleanup;
}
def->current = active != 0;
}
if (!offline && virSaveCookieParse(ctxt, &def->cookie, saveCookie) < 0)
goto cleanup;
ret = def;
cleanup:
VIR_FREE(creation);
VIR_FREE(state);
VIR_FREE(nodes);
VIR_FREE(memorySnapshot);
VIR_FREE(memoryFile);
if (ret == NULL)
virDomainSnapshotDefFree(def);
return ret;
}
virDomainSnapshotDefPtr
virDomainSnapshotDefParseNode(xmlDocPtr xml,
xmlNodePtr root,
virCapsPtr caps,
virDomainXMLOptionPtr xmlopt,
unsigned int flags)
{
xmlXPathContextPtr ctxt = NULL;
virDomainSnapshotDefPtr def = NULL;
if (!virXMLNodeNameEqual(root, "domainsnapshot")) {
virReportError(VIR_ERR_XML_ERROR, "%s", _("domainsnapshot"));
goto cleanup;
}
ctxt = xmlXPathNewContext(xml);
if (ctxt == NULL) {
virReportOOMError();
goto cleanup;
}
ctxt->node = root;
def = virDomainSnapshotDefParse(ctxt, caps, xmlopt, flags);
cleanup:
xmlXPathFreeContext(ctxt);
return def;
}
virDomainSnapshotDefPtr
virDomainSnapshotDefParseString(const char *xmlStr,
virCapsPtr caps,
virDomainXMLOptionPtr xmlopt,
unsigned int flags)
{
virDomainSnapshotDefPtr ret = NULL;
xmlDocPtr xml;
int keepBlanksDefault = xmlKeepBlanksDefault(0);
if ((xml = virXMLParse(NULL, xmlStr, _("(domain_snapshot)")))) {
xmlKeepBlanksDefault(keepBlanksDefault);
ret = virDomainSnapshotDefParseNode(xml, xmlDocGetRootElement(xml),
caps, xmlopt, flags);
xmlFreeDoc(xml);
}
xmlKeepBlanksDefault(keepBlanksDefault);
return ret;
}
/**
* virDomainSnapshotDefAssignExternalNames:
* @def: snapshot def object
*
* Generate default external file names for snapshot targets. Returns 0 on
* success, -1 on error.
*/
static int
virDomainSnapshotDefAssignExternalNames(virDomainSnapshotDefPtr def)
{
const char *origpath;
char *tmppath;
char *tmp;
struct stat sb;
size_t i;
size_t j;
for (i = 0; i < def->ndisks; i++) {
virDomainSnapshotDiskDefPtr disk = &def->disks[i];
if (disk->snapshot != VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL ||
disk->src->path)
continue;
if (disk->src->type != VIR_STORAGE_TYPE_FILE) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("cannot generate external snapshot name "
"for disk '%s' on a '%s' device"),
disk->name, virStorageTypeToString(disk->src->type));
return -1;
}
if (!(origpath = virDomainDiskGetSource(def->dom->disks[i]))) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("cannot generate external snapshot name "
"for disk '%s' without source"),
disk->name);
return -1;
}
if (stat(origpath, &sb) < 0 || !S_ISREG(sb.st_mode)) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("source for disk '%s' is not a regular "
"file; refusing to generate external "
"snapshot name"),
disk->name);
return -1;
}
if (VIR_STRDUP(tmppath, origpath) < 0)
return -1;
/* drop suffix of the file name */
if ((tmp = strrchr(tmppath, '.')) && !strchr(tmp, '/'))
*tmp = '\0';
if (virAsprintf(&disk->src->path, "%s.%s", tmppath, def->name) < 0) {
VIR_FREE(tmppath);
return -1;
}
VIR_FREE(tmppath);
/* verify that we didn't generate a duplicate name */
for (j = 0; j < i; j++) {
if (STREQ_NULLABLE(disk->src->path, def->disks[j].src->path)) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("cannot generate external snapshot name for "
"disk '%s': collision with disk '%s'"),
disk->name, def->disks[j].name);
return -1;
}
}
}
return 0;
}
static int
virDomainSnapshotCompareDiskIndex(const void *a, const void *b)
{
const virDomainSnapshotDiskDef *diska = a;
const virDomainSnapshotDiskDef *diskb = b;
/* Integer overflow shouldn't be a problem here. */
return diska->idx - diskb->idx;
}
/* Align def->disks to def->domain. Sort the list of def->disks,
* filling in any missing disks or snapshot state defaults given by
* the domain, with a fallback to a passed in default. 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. If require_match, also ensure that there is no
* conflicting requests for both internal and external snapshots. */
int
virDomainSnapshotAlignDisks(virDomainSnapshotDefPtr def,
int default_snapshot,
bool require_match)
{
int ret = -1;
virBitmapPtr map = NULL;
size_t i;
int ndisks;
if (!def->dom) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("missing domain in snapshot"));
goto cleanup;
}
if (def->ndisks > def->dom->ndisks) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
_("too many disk snapshot requests for domain"));
goto cleanup;
}
/* Unlikely to have a guest without disks but technically possible. */
if (!def->dom->ndisks) {
ret = 0;
goto cleanup;
}
if (!(map = virBitmapNew(def->dom->ndisks)))
goto cleanup;
/* Double check requested disks. */
for (i = 0; i < def->ndisks; i++) {
virDomainSnapshotDiskDefPtr disk = &def->disks[i];
int idx = virDomainDiskIndexByName(def->dom, disk->name, false);
int disk_snapshot;
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;
disk_snapshot = def->dom->disks[idx]->snapshot;
if (!disk->snapshot) {
if (disk_snapshot &&
(!require_match ||
disk_snapshot == VIR_DOMAIN_SNAPSHOT_LOCATION_NONE))
disk->snapshot = disk_snapshot;
else
disk->snapshot = default_snapshot;
} else if (require_match &&
disk->snapshot != default_snapshot &&
!(disk->snapshot == VIR_DOMAIN_SNAPSHOT_LOCATION_NONE &&
disk_snapshot == VIR_DOMAIN_SNAPSHOT_LOCATION_NONE)) {
const char *tmp;
tmp = virDomainSnapshotLocationTypeToString(default_snapshot);
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("disk '%s' must use snapshot mode '%s'"),
disk->name, tmp);
goto cleanup;
}
if (disk->src->path &&
disk->snapshot != VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
_("file '%s' for disk '%s' requires "
"use of external snapshot mode"),
disk->src->path, disk->name);
goto cleanup;
}
if (STRNEQ(disk->name, def->dom->disks[idx]->dst)) {
VIR_FREE(disk->name);
if (VIR_STRDUP(disk->name, def->dom->disks[idx]->dst) < 0)
goto cleanup;
}
}
/* Provide defaults for all remaining disks. */
ndisks = def->ndisks;
if (VIR_EXPAND_N(def->disks, def->ndisks,
def->dom->ndisks - def->ndisks) < 0)
goto cleanup;
for (i = 0; i < def->dom->ndisks; i++) {
virDomainSnapshotDiskDefPtr disk;
if (virBitmapIsBitSet(map, i))
continue;
disk = &def->disks[ndisks++];
if (VIR_ALLOC(disk->src) < 0)
goto cleanup;
if (VIR_STRDUP(disk->name, def->dom->disks[i]->dst) < 0)
goto cleanup;
disk->idx = i;
/* Don't snapshot empty drives */
if (virStorageSourceIsEmpty(def->dom->disks[i]->src))
disk->snapshot = VIR_DOMAIN_SNAPSHOT_LOCATION_NONE;
else
disk->snapshot = def->dom->disks[i]->snapshot;
disk->src->type = VIR_STORAGE_TYPE_FILE;
if (!disk->snapshot)
disk->snapshot = default_snapshot;
}
qsort(&def->disks[0], def->ndisks, sizeof(def->disks[0]),
virDomainSnapshotCompareDiskIndex);
/* Generate default external file names for external snapshot locations */
if (virDomainSnapshotDefAssignExternalNames(def) < 0)
goto cleanup;
ret = 0;
cleanup:
virBitmapFree(map);
return ret;
}
static int
virDomainSnapshotDiskDefFormat(virBufferPtr buf,
virDomainSnapshotDiskDefPtr disk,
virDomainXMLOptionPtr xmlopt)
{
int type = disk->src->type;
if (!disk->name)
return 0;
virBufferEscapeString(buf, "<disk name='%s'", disk->name);
if (disk->snapshot > 0)
virBufferAsprintf(buf, " snapshot='%s'",
virDomainSnapshotLocationTypeToString(disk->snapshot));
if (!disk->src->path && disk->src->format == 0) {
virBufferAddLit(buf, "/>\n");
return 0;
}
virBufferAsprintf(buf, " type='%s'>\n", virStorageTypeToString(type));
virBufferAdjustIndent(buf, 2);
if (disk->src->format > 0)
virBufferEscapeString(buf, "<driver type='%s'/>\n",
virStorageFileFormatTypeToString(disk->src->format));
if (virDomainDiskSourceFormat(buf, disk->src, 0, 0, xmlopt) < 0)
return -1;
virBufferAdjustIndent(buf, -2);
virBufferAddLit(buf, "</disk>\n");
return 0;
}
char *
virDomainSnapshotDefFormat(const char *domain_uuid,
virDomainSnapshotDefPtr def,
virCapsPtr caps,
virDomainXMLOptionPtr xmlopt,
unsigned int flags,
int internal)
{
virBuffer buf = VIR_BUFFER_INITIALIZER;
size_t i;
virCheckFlags(VIR_DOMAIN_DEF_FORMAT_SECURE, NULL);
flags |= VIR_DOMAIN_DEF_FORMAT_INACTIVE;
virBufferAddLit(&buf, "<domainsnapshot>\n");
virBufferAdjustIndent(&buf, 2);
virBufferEscapeString(&buf, "<name>%s</name>\n", def->name);
if (def->description)
virBufferEscapeString(&buf, "<description>%s</description>\n",
def->description);
virBufferAsprintf(&buf, "<state>%s</state>\n",
virDomainSnapshotStateTypeToString(def->state));
if (def->parent) {
virBufferAddLit(&buf, "<parent>\n");
virBufferAdjustIndent(&buf, 2);
virBufferEscapeString(&buf, "<name>%s</name>\n", def->parent);
virBufferAdjustIndent(&buf, -2);
virBufferAddLit(&buf, "</parent>\n");
}
virBufferAsprintf(&buf, "<creationTime>%lld</creationTime>\n",
def->creationTime);
if (def->memory) {
virBufferAsprintf(&buf, "<memory snapshot='%s'",
virDomainSnapshotLocationTypeToString(def->memory));
virBufferEscapeString(&buf, " file='%s'", def->file);
virBufferAddLit(&buf, "/>\n");
}
if (def->ndisks) {
virBufferAddLit(&buf, "<disks>\n");
virBufferAdjustIndent(&buf, 2);
for (i = 0; i < def->ndisks; i++) {
if (virDomainSnapshotDiskDefFormat(&buf, &def->disks[i], xmlopt) < 0)
goto error;
}
virBufferAdjustIndent(&buf, -2);
virBufferAddLit(&buf, "</disks>\n");
}
if (def->dom) {
if (virDomainDefFormatInternal(def->dom, caps, flags, &buf, xmlopt) < 0)
goto error;
} else if (domain_uuid) {
virBufferAddLit(&buf, "<domain>\n");
virBufferAdjustIndent(&buf, 2);
virBufferAsprintf(&buf, "<uuid>%s</uuid>\n", domain_uuid);
virBufferAdjustIndent(&buf, -2);
virBufferAddLit(&buf, "</domain>\n");
}
if (virSaveCookieFormatBuf(&buf, def->cookie,
virDomainXMLOptionGetSaveCookie(xmlopt)) < 0)
goto error;
if (internal)
virBufferAsprintf(&buf, "<active>%d</active>\n", def->current);
virBufferAdjustIndent(&buf, -2);
virBufferAddLit(&buf, "</domainsnapshot>\n");
if (virBufferCheckError(&buf) < 0)
return NULL;
return virBufferContentAndReset(&buf);
error:
virBufferFreeAndReset(&buf);
return NULL;
}
/* Snapshot Obj functions */
static virDomainSnapshotObjPtr virDomainSnapshotObjNew(void)
{
virDomainSnapshotObjPtr snapshot;
if (VIR_ALLOC(snapshot) < 0)
return NULL;
VIR_DEBUG("obj=%p", snapshot);
return snapshot;
}
static void virDomainSnapshotObjFree(virDomainSnapshotObjPtr snapshot)
{
if (!snapshot)
return;
VIR_DEBUG("obj=%p", snapshot);
virDomainSnapshotDefFree(snapshot->def);
VIR_FREE(snapshot);
}
virDomainSnapshotObjPtr virDomainSnapshotAssignDef(virDomainSnapshotObjListPtr snapshots,
virDomainSnapshotDefPtr def)
{
virDomainSnapshotObjPtr snap;
if (virHashLookup(snapshots->objs, def->name) != NULL) {
virReportError(VIR_ERR_INTERNAL_ERROR,
_("unexpected domain snapshot %s already exists"),
def->name);
return NULL;
}
if (!(snap = virDomainSnapshotObjNew()))
return NULL;
snap->def = def;
if (virHashAddEntry(snapshots->objs, snap->def->name, snap) < 0) {
VIR_FREE(snap);
return NULL;
}
return snap;
}
/* Snapshot Obj List functions */
static void
virDomainSnapshotObjListDataFree(void *payload,
const void *name ATTRIBUTE_UNUSED)
{
virDomainSnapshotObjPtr obj = payload;
virDomainSnapshotObjFree(obj);
}
virDomainSnapshotObjListPtr
virDomainSnapshotObjListNew(void)
{
virDomainSnapshotObjListPtr snapshots;
if (VIR_ALLOC(snapshots) < 0)
return NULL;
snapshots->objs = virHashCreate(50, virDomainSnapshotObjListDataFree);
if (!snapshots->objs) {
VIR_FREE(snapshots);
return NULL;
}
return snapshots;
}
void
virDomainSnapshotObjListFree(virDomainSnapshotObjListPtr snapshots)
{
if (!snapshots)
return;
virHashFree(snapshots->objs);
VIR_FREE(snapshots);
}
struct virDomainSnapshotNameData {
char **const names;
int maxnames;
unsigned int flags;
int count;
bool error;
};
static int virDomainSnapshotObjListCopyNames(void *payload,
const void *name ATTRIBUTE_UNUSED,
void *opaque)
{
virDomainSnapshotObjPtr obj = payload;
struct virDomainSnapshotNameData *data = opaque;
if (data->error)
return 0;
/* Caller already sanitized flags. Filtering on DESCENDANTS was
* done by choice of iteration in the caller. */
if ((data->flags & VIR_DOMAIN_SNAPSHOT_LIST_LEAVES) && obj->nchildren)
return 0;
if ((data->flags & VIR_DOMAIN_SNAPSHOT_LIST_NO_LEAVES) && !obj->nchildren)
return 0;
if (data->flags & VIR_DOMAIN_SNAPSHOT_FILTERS_STATUS) {
if (!(data->flags & VIR_DOMAIN_SNAPSHOT_LIST_INACTIVE) &&
obj->def->state == VIR_DOMAIN_SHUTOFF)
return 0;
if (!(data->flags & VIR_DOMAIN_SNAPSHOT_LIST_DISK_ONLY) &&
obj->def->state == VIR_DOMAIN_DISK_SNAPSHOT)
return 0;
if (!(data->flags & VIR_DOMAIN_SNAPSHOT_LIST_ACTIVE) &&
obj->def->state != VIR_DOMAIN_SHUTOFF &&
obj->def->state != VIR_DOMAIN_DISK_SNAPSHOT)
return 0;
}
if ((data->flags & VIR_DOMAIN_SNAPSHOT_LIST_INTERNAL) &&
virDomainSnapshotIsExternal(obj))
return 0;
if ((data->flags & VIR_DOMAIN_SNAPSHOT_LIST_EXTERNAL) &&
!virDomainSnapshotIsExternal(obj))
return 0;
if (data->names && data->count < data->maxnames &&
VIR_STRDUP(data->names[data->count], obj->def->name) < 0) {
data->error = true;
return 0;
}
data->count++;
return 0;
}
int
virDomainSnapshotObjListGetNames(virDomainSnapshotObjListPtr snapshots,
virDomainSnapshotObjPtr from,
char **const names, int maxnames,
unsigned int flags)
{
struct virDomainSnapshotNameData data = { names, maxnames, flags, 0,
false };
size_t i;
if (!from) {
/* LIST_ROOTS and LIST_DESCENDANTS have the same bit value,
* but opposite semantics. Toggle here to get the correct
* traversal on the metaroot. */
flags ^= VIR_DOMAIN_SNAPSHOT_LIST_ROOTS;
from = &snapshots->metaroot;
}
/* We handle LIST_ROOT/LIST_DESCENDANTS directly, mask that bit
* out to determine when we must use the filter callback. */
data.flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
/* If this common code is being used, we assume that all snapshots
* have metadata, and thus can handle METADATA up front as an
* all-or-none filter. XXX This might not always be true, if we
* add the ability to track qcow2 internal snapshots without the
* use of metadata. */
if ((data.flags & VIR_DOMAIN_SNAPSHOT_FILTERS_METADATA) ==
VIR_DOMAIN_SNAPSHOT_LIST_NO_METADATA)
return 0;
data.flags &= ~VIR_DOMAIN_SNAPSHOT_FILTERS_METADATA;
/* For ease of coding the visitor, it is easier to zero each group
* where all of the bits are set. */
if ((data.flags & VIR_DOMAIN_SNAPSHOT_FILTERS_LEAVES) ==
VIR_DOMAIN_SNAPSHOT_FILTERS_LEAVES)
data.flags &= ~VIR_DOMAIN_SNAPSHOT_FILTERS_LEAVES;
if ((data.flags & VIR_DOMAIN_SNAPSHOT_FILTERS_STATUS) ==
VIR_DOMAIN_SNAPSHOT_FILTERS_STATUS)
data.flags &= ~VIR_DOMAIN_SNAPSHOT_FILTERS_STATUS;
if ((data.flags & VIR_DOMAIN_SNAPSHOT_FILTERS_LOCATION) ==
VIR_DOMAIN_SNAPSHOT_FILTERS_LOCATION)
data.flags &= ~VIR_DOMAIN_SNAPSHOT_FILTERS_LOCATION;
if (flags & VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS) {
if (from->def)
virDomainSnapshotForEachDescendant(from,
virDomainSnapshotObjListCopyNames,
&data);
else if (names || data.flags)
virHashForEach(snapshots->objs, virDomainSnapshotObjListCopyNames,
&data);
else
data.count = virHashSize(snapshots->objs);
} else if (names || data.flags) {
virDomainSnapshotForEachChild(from,
virDomainSnapshotObjListCopyNames, &data);
} else {
data.count = from->nchildren;
}
if (data.error) {
for (i = 0; i < data.count; i++)
VIR_FREE(names[i]);
return -1;
}
return data.count;
}
int
virDomainSnapshotObjListNum(virDomainSnapshotObjListPtr snapshots,
virDomainSnapshotObjPtr from,
unsigned int flags)
{
return virDomainSnapshotObjListGetNames(snapshots, from, NULL, 0, flags);
}
virDomainSnapshotObjPtr
virDomainSnapshotFindByName(virDomainSnapshotObjListPtr snapshots,
const char *name)
{
return name ? virHashLookup(snapshots->objs, name) : &snapshots->metaroot;
}
void virDomainSnapshotObjListRemove(virDomainSnapshotObjListPtr snapshots,
virDomainSnapshotObjPtr snapshot)
{
virHashRemoveEntry(snapshots->objs, snapshot->def->name);
}
int
virDomainSnapshotForEach(virDomainSnapshotObjListPtr snapshots,
virHashIterator iter,
void *data)
{
return virHashForEach(snapshots->objs, iter, data);
}
/* Run iter(data) on all direct children of snapshot, while ignoring all
* other entries in snapshots. Return the number of children
* visited. No particular ordering is guaranteed. */
int
virDomainSnapshotForEachChild(virDomainSnapshotObjPtr snapshot,
virHashIterator iter,
void *data)
{
virDomainSnapshotObjPtr child = snapshot->first_child;
while (child) {
virDomainSnapshotObjPtr next = child->sibling;
(iter)(child, child->def->name, data);
child = next;
}
return snapshot->nchildren;
}
struct snapshot_act_on_descendant {
int number;
virHashIterator iter;
void *data;
};
static int
virDomainSnapshotActOnDescendant(void *payload,
const void *name,
void *data)
{
virDomainSnapshotObjPtr obj = payload;
struct snapshot_act_on_descendant *curr = data;
curr->number += 1 + virDomainSnapshotForEachDescendant(obj,
curr->iter,
curr->data);
(curr->iter)(payload, name, curr->data);
return 0;
}
/* Run iter(data) on all descendants of snapshot, while ignoring all
* other entries in snapshots. Return the number of descendants
* visited. No particular ordering is guaranteed. */
int
virDomainSnapshotForEachDescendant(virDomainSnapshotObjPtr snapshot,
virHashIterator iter,
void *data)
{
struct snapshot_act_on_descendant act;
act.number = 0;
act.iter = iter;
act.data = data;
virDomainSnapshotForEachChild(snapshot,
virDomainSnapshotActOnDescendant, &act);
return act.number;
}
/* Struct and callback function used as a hash table callback; each call
* inspects the pre-existing snapshot->def->parent field, and adjusts
* the snapshot->parent field as well as the parent's child fields to
* wire up the hierarchical relations for the given snapshot. The error
* indicator gets set if a parent is missing or a requested parent would
* cause a circular parent chain. */
struct snapshot_set_relation {
virDomainSnapshotObjListPtr snapshots;
int err;
};
static int
virDomainSnapshotSetRelations(void *payload,
const void *name ATTRIBUTE_UNUSED,
void *data)
{
virDomainSnapshotObjPtr obj = payload;
struct snapshot_set_relation *curr = data;
virDomainSnapshotObjPtr tmp;
obj->parent = virDomainSnapshotFindByName(curr->snapshots,
obj->def->parent);
if (!obj->parent) {
curr->err = -1;
obj->parent = &curr->snapshots->metaroot;
VIR_WARN("snapshot %s lacks parent", obj->def->name);
} else {
tmp = obj->parent;
while (tmp && tmp->def) {
if (tmp == obj) {
curr->err = -1;
obj->parent = &curr->snapshots->metaroot;
VIR_WARN("snapshot %s in circular chain", obj->def->name);
break;
}
tmp = tmp->parent;
}
}
obj->parent->nchildren++;
obj->sibling = obj->parent->first_child;
obj->parent->first_child = obj;
return 0;
}
/* Populate parent link and child count of all snapshots, with all
* relations starting as 0/NULL. Return 0 on success, -1 if a parent
* is missing or if a circular relationship was requested. */
int
virDomainSnapshotUpdateRelations(virDomainSnapshotObjListPtr snapshots)
{
struct snapshot_set_relation act = { snapshots, 0 };
virHashForEach(snapshots->objs, virDomainSnapshotSetRelations, &act);
return act.err;
}
/* Prepare to reparent or delete snapshot, by removing it from its
* current listed parent. Note that when bulk removing all children
* of a parent, it is faster to just 0 the count rather than calling
* this function on each child. */
void
virDomainSnapshotDropParent(virDomainSnapshotObjPtr snapshot)
{
virDomainSnapshotObjPtr prev = NULL;
virDomainSnapshotObjPtr curr = NULL;
snapshot->parent->nchildren--;
curr = snapshot->parent->first_child;
while (curr != snapshot) {
if (!curr) {
VIR_WARN("inconsistent snapshot relations");
return;
}
prev = curr;
curr = curr->sibling;
}
if (prev)
prev->sibling = snapshot->sibling;
else
snapshot->parent->first_child = snapshot->sibling;
snapshot->parent = NULL;
snapshot->sibling = NULL;
}
int
virDomainListSnapshots(virDomainSnapshotObjListPtr snapshots,
virDomainSnapshotObjPtr from,
virDomainPtr dom,
virDomainSnapshotPtr **snaps,
unsigned int flags)
{
int count = virDomainSnapshotObjListNum(snapshots, from, flags);
virDomainSnapshotPtr *list = NULL;
char **names;
int ret = -1;
size_t i;
if (!snaps || count < 0)
return count;
if (VIR_ALLOC_N(names, count) < 0 ||
VIR_ALLOC_N(list, count + 1) < 0)
goto cleanup;
if (virDomainSnapshotObjListGetNames(snapshots, from, names, count,
flags) < 0)
goto cleanup;
for (i = 0; i < count; i++)
if ((list[i] = virGetDomainSnapshot(dom, names[i])) == NULL)
goto cleanup;
ret = count;
*snaps = list;
cleanup:
for (i = 0; i < count; i++)
VIR_FREE(names[i]);
VIR_FREE(names);
if (ret < 0 && list) {
for (i = 0; i < count; i++)
virObjectUnref(list[i]);
VIR_FREE(list);
}
return ret;
}
bool
virDomainSnapshotDefIsExternal(virDomainSnapshotDefPtr def)
{
size_t i;
if (def->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL)
return true;
for (i = 0; i < def->ndisks; i++) {
if (def->disks[i].snapshot == VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL)
return true;
}
return false;
}
bool
virDomainSnapshotIsExternal(virDomainSnapshotObjPtr snap)
{
return virDomainSnapshotDefIsExternal(snap->def);
}
int
virDomainSnapshotRedefinePrep(virDomainPtr domain,
virDomainObjPtr vm,
virDomainSnapshotDefPtr *defptr,
virDomainSnapshotObjPtr *snap,
virDomainXMLOptionPtr xmlopt,
bool *update_current,
unsigned int flags)
{
virDomainSnapshotDefPtr def = *defptr;
int ret = -1;
int align_location = VIR_DOMAIN_SNAPSHOT_LOCATION_INTERNAL;
bool align_match = true;
char uuidstr[VIR_UUID_STRING_BUFLEN];
virDomainSnapshotObjPtr other;
virUUIDFormat(domain->uuid, uuidstr);
/* Prevent circular chains */
if (def->parent) {
if (STREQ(def->name, def->parent)) {
virReportError(VIR_ERR_INVALID_ARG,
_("cannot set snapshot %s as its own parent"),
def->name);
goto cleanup;
}
other = virDomainSnapshotFindByName(vm->snapshots, def->parent);
if (!other) {
virReportError(VIR_ERR_INVALID_ARG,
_("parent %s for snapshot %s not found"),
def->parent, def->name);
goto cleanup;
}
while (other->def->parent) {
if (STREQ(other->def->parent, def->name)) {
virReportError(VIR_ERR_INVALID_ARG,
_("parent %s would create cycle to %s"),
other->def->name, def->name);
goto cleanup;
}
other = virDomainSnapshotFindByName(vm->snapshots,
other->def->parent);
if (!other) {
VIR_WARN("snapshots are inconsistent for %s",
vm->def->name);
break;
}
}
}
/* Check that any replacement is compatible */
if ((flags & VIR_DOMAIN_SNAPSHOT_CREATE_DISK_ONLY) &&
def->state != VIR_DOMAIN_DISK_SNAPSHOT) {
virReportError(VIR_ERR_INVALID_ARG,
_("disk-only flag for snapshot %s requires "
"disk-snapshot state"),
def->name);
goto cleanup;
}
if (def->dom &&
memcmp(def->dom->uuid, domain->uuid, VIR_UUID_BUFLEN)) {
virReportError(VIR_ERR_INVALID_ARG,
_("definition for snapshot %s must use uuid %s"),
def->name, uuidstr);
goto cleanup;
}
other = virDomainSnapshotFindByName(vm->snapshots, def->name);
if (other) {
if ((other->def->state == VIR_DOMAIN_RUNNING ||
other->def->state == VIR_DOMAIN_PAUSED) !=
(def->state == VIR_DOMAIN_RUNNING ||
def->state == VIR_DOMAIN_PAUSED)) {
virReportError(VIR_ERR_INVALID_ARG,
_("cannot change between online and offline "
"snapshot state in snapshot %s"),
def->name);
goto cleanup;
}
if ((other->def->state == VIR_DOMAIN_DISK_SNAPSHOT) !=
(def->state == VIR_DOMAIN_DISK_SNAPSHOT)) {
virReportError(VIR_ERR_INVALID_ARG,
_("cannot change between disk snapshot and "
"system checkpoint in snapshot %s"),
def->name);
goto cleanup;
}
if (other->def->dom) {
if (def->dom) {
if (!virDomainDefCheckABIStability(other->def->dom,
def->dom, xmlopt))
goto cleanup;
} else {
/* Transfer the domain def */
def->dom = other->def->dom;
other->def->dom = NULL;
}
}
if (def->dom) {
if (def->state == VIR_DOMAIN_DISK_SNAPSHOT ||
virDomainSnapshotDefIsExternal(def)) {
align_location = VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL;
align_match = false;
}
if (virDomainSnapshotAlignDisks(def, align_location,
align_match) < 0) {
/* revert stealing of the snapshot domain definition */
if (def->dom && !other->def->dom) {
other->def->dom = def->dom;
def->dom = NULL;
}
goto cleanup;
}
}
if (other == vm->current_snapshot) {
*update_current = true;
vm->current_snapshot = NULL;
}
/* Drop and rebuild the parent relationship, but keep all
* child relations by reusing snap. */
virDomainSnapshotDropParent(other);
virDomainSnapshotDefFree(other->def);
other->def = def;
*defptr = NULL;
*snap = other;
} else {
if (def->dom) {
if (def->state == VIR_DOMAIN_DISK_SNAPSHOT ||
def->memory == VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL) {
align_location = VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL;
align_match = false;
}
if (virDomainSnapshotAlignDisks(def, align_location,
align_match) < 0)
goto cleanup;
}
}
ret = 0;
cleanup:
return ret;
}
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