snapshot: track qemu snapshot relations

Maintain the parent/child relationships of all qemu snapshots.

* src/qemu/qemu_driver.c (qemuDomainSnapshotLoad): Populate
relationships after loading.
(qemuDomainSnapshotCreateXML): Set relations on creation; tweak
redefinition to reuse existing object.
(qemuDomainSnapshotReparentChildren, qemuDomainSnapshotDelete):
Clear relations on delete.
This commit is contained in:
Eric Blake 2011-10-07 15:00:03 -06:00
parent 7ec6f7bd33
commit 9279bdf757

View File

@ -376,6 +376,10 @@ static void qemuDomainSnapshotLoad(void *payload,
vm->current_snapshot = NULL;
}
if (virDomainSnapshotUpdateRelations(&vm->snapshots) < 0)
VIR_ERROR(_("Snapshots have inconsistent relations for domain %s"),
vm->def->name);
/* FIXME: qemu keeps internal track of snapshots. We can get access
* to this info via the "info snapshots" monitor command for running
* domains, or via "qemu-img snapshot -l" for shutoff domains. It would
@ -9148,6 +9152,7 @@ qemuDomainSnapshotCreateXML(virDomainPtr domain,
virDomainSnapshotDefPtr def = NULL;
bool update_current = true;
unsigned int parse_flags = 0;
virDomainSnapshotObjPtr other = NULL;
virCheckFlags(VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE |
VIR_DOMAIN_SNAPSHOT_CREATE_CURRENT |
@ -9190,8 +9195,6 @@ qemuDomainSnapshotCreateXML(virDomainPtr domain,
goto cleanup;
if (flags & VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE) {
virDomainSnapshotObjPtr other = NULL;
/* Prevent circular chains */
if (def->parent) {
if (STREQ(def->name, def->parent)) {
@ -9267,7 +9270,12 @@ qemuDomainSnapshotCreateXML(virDomainPtr domain,
update_current = true;
vm->current_snapshot = NULL;
}
virDomainSnapshotObjListRemove(&vm->snapshots, other);
/* Drop and rebuild the parent relationship, but keep all
* child relations by reusing snap. */
virDomainSnapshotDropParent(&vm->snapshots, other);
virDomainSnapshotDefFree(other->def);
other->def = NULL;
snap = other;
}
if (def->state == VIR_DOMAIN_DISK_SNAPSHOT && def->dom) {
if (virDomainSnapshotAlignDisks(def,
@ -9309,7 +9317,9 @@ qemuDomainSnapshotCreateXML(virDomainPtr domain,
}
}
if (!(snap = virDomainSnapshotAssignDef(&vm->snapshots, def)))
if (snap)
snap->def = def;
else if (!(snap = virDomainSnapshotAssignDef(&vm->snapshots, def)))
goto cleanup;
def = NULL;
@ -9366,11 +9376,25 @@ cleanup:
if (vm) {
if (snapshot && !(flags & VIR_DOMAIN_SNAPSHOT_CREATE_NO_METADATA)) {
if (qemuDomainSnapshotWriteMetadata(vm, snap,
driver->snapshotDir) < 0)
driver->snapshotDir) < 0) {
VIR_WARN("unable to save metadata for snapshot %s",
snap->def->name);
else if (update_current)
vm->current_snapshot = snap;
} else {
if (update_current)
vm->current_snapshot = snap;
if (snap->def->parent) {
other = virDomainSnapshotFindByName(&vm->snapshots,
snap->def->parent);
snap->parent = other;
other->nchildren++;
snap->sibling = other->first_child;
other->first_child = snap;
} else {
vm->snapshots.nroots++;
snap->sibling = vm->snapshots.first_root;
vm->snapshots.first_root = snap;
}
}
} else if (snap) {
virDomainSnapshotObjListRemove(&vm->snapshots, snap);
}
@ -10062,9 +10086,10 @@ cleanup:
struct snap_reparent {
struct qemud_driver *driver;
const char *parent;
virDomainSnapshotObjPtr parent;
virDomainObjPtr vm;
int err;
virDomainSnapshotObjPtr last;
};
static void
@ -10080,9 +10105,10 @@ qemuDomainSnapshotReparentChildren(void *payload,
}
VIR_FREE(snap->def->parent);
snap->parent = rep->parent;
if (rep->parent != NULL) {
snap->def->parent = strdup(rep->parent);
if (rep->parent) {
snap->def->parent = strdup(rep->parent->def->name);
if (snap->def->parent == NULL) {
virReportOOMError();
@ -10091,6 +10117,9 @@ qemuDomainSnapshotReparentChildren(void *payload,
}
}
if (!snap->sibling)
rep->last = snap;
rep->err = qemuDomainSnapshotWriteMetadata(rep->vm, snap,
rep->driver->snapshotDir);
}
@ -10175,22 +10204,37 @@ static int qemuDomainSnapshotDelete(virDomainSnapshotPtr snapshot,
}
vm->current_snapshot = snap;
}
} else {
} else if (snap->nchildren) {
rep.driver = driver;
rep.parent = snap->def->parent;
rep.parent = snap->parent;
rep.vm = vm;
rep.err = 0;
rep.last = NULL;
virDomainSnapshotForEachChild(&vm->snapshots, snap,
qemuDomainSnapshotReparentChildren,
&rep);
if (rep.err < 0)
goto endjob;
/* Can't modify siblings during ForEachChild, so do it now. */
if (snap->parent) {
snap->parent->nchildren += snap->nchildren;
rep.last->sibling = snap->parent->first_child;
snap->parent->first_child = snap->first_child;
} else {
vm->snapshots.nroots += snap->nchildren;
rep.last->sibling = vm->snapshots.first_root;
vm->snapshots.first_root = snap->first_child;
}
}
if (flags & VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN_ONLY)
if (flags & VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN_ONLY) {
snap->nchildren = 0;
snap->first_child = NULL;
ret = 0;
else
} else {
virDomainSnapshotDropParent(&vm->snapshots, snap);
ret = qemuDomainSnapshotDiscard(driver, vm, snap, true, metadata_only);
}
endjob:
if (qemuDomainObjEndJob(driver, vm) == 0)