[libvirt] [PATCHv4 23/51] snapshot: add qemu snapshot redefine support
Eric Blake
eblake at redhat.com
Fri Sep 2 04:25:00 UTC 2011
Redefining a qemu snapshot requires a bit of a tweak to the common
snapshot parsing code, but the end result is quite nice.
* src/conf/domain_conf.h (virDomainSnapshotParseFlags): New
internal flags.
* src/conf/domain_conf.c (virDomainSnapshotDefParseString): Alter
signature to take internal flags.
* src/esx/esx_driver.c (esxDomainSnapshotCreateXML): Update caller.
* src/vbox/vbox_tmpl.c (vboxDomainSnapshotCreateXML): Likewise.
* src/qemu/qemu_driver.c (qemuDomainSnapshotCreateXML): Support
new public flags.
---
src/conf/domain_conf.c | 25 +++++++++++++++------
src/conf/domain_conf.h | 7 +++++-
src/esx/esx_driver.c | 2 +-
src/qemu/qemu_driver.c | 57 +++++++++++++++++++++++++++++++++++++----------
src/vbox/vbox_tmpl.c | 2 +-
5 files changed, 71 insertions(+), 22 deletions(-)
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 1b2fd61..009d9c1 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -10953,8 +10953,9 @@ void virDomainSnapshotDefFree(virDomainSnapshotDefPtr def)
VIR_FREE(def);
}
-virDomainSnapshotDefPtr virDomainSnapshotDefParseString(const char *xmlStr,
- int newSnapshot)
+/* flags are from virDomainSnapshotParseFlags */
+virDomainSnapshotDefPtr
+virDomainSnapshotDefParseString(const char *xmlStr, unsigned int flags)
{
xmlXPathContextPtr ctxt = NULL;
xmlDocPtr xml = NULL;
@@ -10982,8 +10983,16 @@ virDomainSnapshotDefPtr virDomainSnapshotDefParseString(const char *xmlStr,
gettimeofday(&tv, NULL);
def->name = virXPathString("string(./name)", ctxt);
- if (def->name == NULL)
- ignore_value(virAsprintf(&def->name, "%lld", (long long)tv.tv_sec));
+ if (def->name == NULL) {
+ if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE) {
+ virDomainReportError(VIR_ERR_XML_ERROR, "%s",
+ _("a redefined snapshot must have a name"));
+ goto cleanup;
+ } else {
+ ignore_value(virAsprintf(&def->name, "%lld",
+ (long long)tv.tv_sec));
+ }
+ }
if (def->name == NULL) {
virReportOOMError();
@@ -10992,7 +11001,7 @@ virDomainSnapshotDefPtr virDomainSnapshotDefParseString(const char *xmlStr,
def->description = virXPathString("string(./description)", ctxt);
- if (!newSnapshot) {
+ if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE) {
if (virXPathLongLong("string(./creationTime)", ctxt,
&def->creationTime) < 0) {
virDomainReportError(VIR_ERR_INTERNAL_ERROR, "%s",
@@ -11018,7 +11027,11 @@ virDomainSnapshotDefPtr virDomainSnapshotDefParseString(const char *xmlStr,
state);
goto cleanup;
}
+ } else {
+ def->creationTime = tv.tv_sec;
+ }
+ if (flags & VIR_DOMAIN_SNAPSHOT_PARSE_INTERNAL) {
if (virXPathInt("string(./active)", ctxt, &active) < 0) {
virDomainReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("Could not find 'active' element"));
@@ -11026,8 +11039,6 @@ virDomainSnapshotDefPtr virDomainSnapshotDefParseString(const char *xmlStr,
}
def->current = active != 0;
}
- else
- def->creationTime = tv.tv_sec;
ret = def;
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 503fb58..5e4c67e 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1324,8 +1324,13 @@ struct _virDomainSnapshotObjList {
virHashTable *objs;
};
+typedef enum {
+ VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE = 1 << 0,
+ VIR_DOMAIN_SNAPSHOT_PARSE_INTERNAL = 1 << 1,
+} virDomainSnapshotParseFlags;
+
virDomainSnapshotDefPtr virDomainSnapshotDefParseString(const char *xmlStr,
- int newSnapshot);
+ unsigned int flags);
void virDomainSnapshotDefFree(virDomainSnapshotDefPtr def);
char *virDomainSnapshotDefFormat(char *domain_uuid,
virDomainSnapshotDefPtr def,
diff --git a/src/esx/esx_driver.c b/src/esx/esx_driver.c
index 1e87664..e004324 100644
--- a/src/esx/esx_driver.c
+++ b/src/esx/esx_driver.c
@@ -4217,7 +4217,7 @@ esxDomainSnapshotCreateXML(virDomainPtr domain, const char *xmlDesc,
return NULL;
}
- def = virDomainSnapshotDefParseString(xmlDesc, 1);
+ def = virDomainSnapshotDefParseString(xmlDesc, 0);
if (def == NULL) {
return NULL;
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 6869b02..ac71b04 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -297,6 +297,8 @@ static void qemuDomainSnapshotLoad(void *payload,
virDomainSnapshotObjPtr snap = NULL;
virDomainSnapshotObjPtr current = NULL;
char ebuf[1024];
+ unsigned int flags = (VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE |
+ VIR_DOMAIN_SNAPSHOT_PARSE_INTERNAL);
virDomainObjLock(vm);
if (virAsprintf(&snapDir, "%s/%s", baseDir, vm->def->name) < 0) {
@@ -338,7 +340,7 @@ static void qemuDomainSnapshotLoad(void *payload,
continue;
}
- def = virDomainSnapshotDefParseString(xmlStr, 0);
+ def = virDomainSnapshotDefParseString(xmlStr, flags);
if (def == NULL) {
/* Nothing we can do here, skip this one */
VIR_ERROR(_("Failed to parse snapshot XML from file '%s'"),
@@ -8583,8 +8585,19 @@ static virDomainSnapshotPtr qemuDomainSnapshotCreateXML(virDomainPtr domain,
virDomainSnapshotPtr snapshot = NULL;
char uuidstr[VIR_UUID_STRING_BUFLEN];
virDomainSnapshotDefPtr def = NULL;
+ bool update_current = true;
+ unsigned int parse_flags = 0;
- virCheckFlags(VIR_DOMAIN_SNAPSHOT_CREATE_NO_METADATA, NULL);
+ virCheckFlags(VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE |
+ VIR_DOMAIN_SNAPSHOT_CREATE_CURRENT |
+ VIR_DOMAIN_SNAPSHOT_CREATE_NO_METADATA, NULL);
+
+ if (((flags & VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE) &&
+ !(flags & VIR_DOMAIN_SNAPSHOT_CREATE_CURRENT)) ||
+ (flags & VIR_DOMAIN_SNAPSHOT_CREATE_NO_METADATA))
+ update_current = false;
+ if (flags & VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE)
+ parse_flags |= VIR_DOMAIN_SNAPSHOT_PARSE_REDEFINE;
qemuDriverLock(driver);
virUUIDFormat(domain->uuid, uuidstr);
@@ -8611,22 +8624,36 @@ static virDomainSnapshotPtr qemuDomainSnapshotCreateXML(virDomainPtr domain,
if (!qemuDomainSnapshotIsAllowed(vm))
goto cleanup;
- if (!(def = virDomainSnapshotDefParseString(xmlDesc, 1)))
+ if (!(def = virDomainSnapshotDefParseString(xmlDesc, parse_flags)))
goto cleanup;
+ if (flags & VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE) {
+ virDomainSnapshotObjPtr prior = NULL;
+
+ prior = virDomainSnapshotFindByName(&vm->snapshots, def->name);
+ if (prior) {
+ /* XXX Ensure ABI compatibility before replacing anything. */
+ virDomainSnapshotObjListRemove(&vm->snapshots, prior);
+ }
+ }
+
if (!(snap = virDomainSnapshotAssignDef(&vm->snapshots, def)))
goto cleanup;
def = NULL;
- snap->def->state = virDomainObjGetState(vm, NULL);
- snap->def->current = true;
+ if (update_current)
+ snap->def->current = true;
+ if (!(flags & VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE))
+ snap->def->state = virDomainObjGetState(vm, NULL);
if (vm->current_snapshot) {
- snap->def->parent = strdup(vm->current_snapshot->def->name);
- if (snap->def->parent == NULL) {
- virReportOOMError();
- goto cleanup;
+ if (!(flags & VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE)) {
+ snap->def->parent = strdup(vm->current_snapshot->def->name);
+ if (snap->def->parent == NULL) {
+ virReportOOMError();
+ goto cleanup;
+ }
}
- if (!(flags & VIR_DOMAIN_SNAPSHOT_CREATE_NO_METADATA)) {
+ if (update_current) {
vm->current_snapshot->def->current = false;
if (qemuDomainSnapshotWriteMetadata(vm, vm->current_snapshot,
driver->snapshotDir) < 0)
@@ -8636,7 +8663,13 @@ static virDomainSnapshotPtr qemuDomainSnapshotCreateXML(virDomainPtr domain,
}
/* actually do the snapshot */
- if (!virDomainObjIsActive(vm)) {
+ if (flags & VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE) {
+ /* XXX Should we validate that the redefined snapshot even
+ * makes sense, such as checking whether the requested parent
+ * snapshot exists and is not creating a loop, or that
+ * qemu-img recognizes the snapshot name in at least one of
+ * the domain's disks? */
+ } else if (!virDomainObjIsActive(vm)) {
if (qemuDomainSnapshotCreateInactive(vm, snap) < 0)
goto cleanup;
} else {
@@ -8658,7 +8691,7 @@ cleanup:
driver->snapshotDir) < 0)
VIR_WARN("unable to save metadata for snapshot %s",
snap->def->name);
- else
+ else if (update_current)
vm->current_snapshot = snap;
} else if (snap) {
virDomainSnapshotObjListRemove(&vm->snapshots, snap);
diff --git a/src/vbox/vbox_tmpl.c b/src/vbox/vbox_tmpl.c
index afe951c..636f5f2 100644
--- a/src/vbox/vbox_tmpl.c
+++ b/src/vbox/vbox_tmpl.c
@@ -5655,7 +5655,7 @@ vboxDomainSnapshotCreateXML(virDomainPtr dom,
/* VBox has no snapshot metadata, so this flag is trivial. */
virCheckFlags(VIR_DOMAIN_SNAPSHOT_CREATE_NO_METADATA, NULL);
- if (!(def = virDomainSnapshotDefParseString(xmlDesc, 1)))
+ if (!(def = virDomainSnapshotDefParseString(xmlDesc, 0)))
goto cleanup;
vboxIIDFromUUID(&domiid, dom->uuid);
--
1.7.4.4
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