snapshot: virsh fallback for snapshot-list --tree --from

Emulating --from requires grabbing the entire list of snapshots
and their parents, and recursively iterating over the list from
the point of interest - but we already do that for --tree.  This
turns on emulation for that situation.

* tools/virsh.c (__vshControl): Rename member.
(vshReconnect, cmdConnect, vshGetSnapshotParent): Update clients.
(cmdSnapshotList): Add fallback.
This commit is contained in:
Eric Blake 2011-09-29 15:18:50 -06:00
parent fe383bb541
commit 510823018e

View File

@ -246,8 +246,8 @@ typedef struct __vshControl {
char *historyfile; /* readline history file name */
bool useGetInfo; /* must use virDomainGetInfo, since
virDomainGetState is not supported */
bool useSnapshotGetXML; /* must use virDomainSnapshotGetXMLDesc, since
virDomainSnapshotGetParent is missing */
bool useSnapshotOld; /* cannot use virDomainSnapshotGetParent or
virDomainSnapshotNumChildren */
} __vshControl;
typedef struct vshCmdGrp {
@ -599,7 +599,7 @@ vshReconnect(vshControl *ctl)
vshError(ctl, "%s", _("Reconnected to the hypervisor"));
disconnected = 0;
ctl->useGetInfo = false;
ctl->useSnapshotGetXML = false;
ctl->useSnapshotOld = false;
}
/* ---------------
@ -747,7 +747,7 @@ cmdConnect(vshControl *ctl, const vshCmd *cmd)
ctl->name = vshStrdup(ctl, name);
ctl->useGetInfo = false;
ctl->useSnapshotGetXML = false;
ctl->useSnapshotOld = false;
ctl->readonly = ro;
ctl->conn = virConnectOpenAuth(ctl->name, virConnectAuthPtrDefault,
@ -13086,7 +13086,7 @@ vshGetSnapshotParent(vshControl *ctl, virDomainSnapshotPtr snapshot,
*parent_name = NULL;
/* Try new API, since it is faster. */
if (!ctl->useSnapshotGetXML) {
if (!ctl->useSnapshotOld) {
parent = virDomainSnapshotGetParent(snapshot, 0);
if (parent) {
/* API works, and virDomainSnapshotGetName will succeed */
@ -13100,7 +13100,7 @@ vshGetSnapshotParent(vshControl *ctl, virDomainSnapshotPtr snapshot,
goto cleanup;
}
/* API didn't work, fall back to XML scraping. */
ctl->useSnapshotGetXML = true;
ctl->useSnapshotOld = true;
}
xml = virDomainSnapshotGetXMLDesc(snapshot, 0);
@ -13225,10 +13225,22 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
if (vshCommandOptBool(cmd, "descendants") || tree) {
flags |= VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
}
numsnaps = virDomainSnapshotNumChildren(start, flags);
if (numsnaps >= 0 && tree)
numsnaps++;
/* XXX Is it worth emulating --from on older servers? */
numsnaps = ctl->useSnapshotOld ? -1 :
virDomainSnapshotNumChildren(start, flags);
/* XXX Is it worth emulating --from without --tree on older servers? */
if (tree) {
if (numsnaps >= 0) {
numsnaps++;
} else if (ctl->useSnapshotOld ||
last_error->code == VIR_ERR_NO_SUPPORT) {
/* We can emulate --tree --from. */
virFreeError(last_error);
last_error = NULL;
ctl->useSnapshotOld = true;
flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_DESCENDANTS;
numsnaps = virDomainSnapshotNum(dom, flags);
}
}
} else {
numsnaps = virDomainSnapshotNum(dom, flags);
@ -13243,8 +13255,11 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
}
}
if (numsnaps < 0)
if (numsnaps < 0) {
if (!last_error)
vshError(ctl, _("missing support"));
goto cleanup;
}
if (!tree) {
if (parent_filter > 0)
@ -13266,7 +13281,7 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
if (VIR_ALLOC_N(names, numsnaps) < 0)
goto cleanup;
if (from) {
if (from && !ctl->useSnapshotOld) {
/* When mixing --from and --tree, we want to start the tree at the
* given snapshot. Without --tree, only list the children. */
if (tree) {
@ -13293,7 +13308,7 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
if (tree) {
char indentBuf[INDENT_BUFLEN];
char **parents = vshCalloc(ctl, sizeof(char *), actual);
for (i = (from ? 1 : 0); i < actual; i++) {
for (i = (from && !ctl->useSnapshotOld); i < actual; i++) {
/* free up memory from previous iterations of the loop */
if (snapshot)
virDomainSnapshotFree(snapshot);
@ -13308,7 +13323,7 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
}
for (i = 0 ; i < actual ; i++) {
memset(indentBuf, '\0', sizeof indentBuf);
if (parents[i] == NULL)
if (ctl->useSnapshotOld ? STREQ(names[i], from) : !parents[i])
cmdNodeListDevicesPrint(ctl,
names,
parents,