[libvirt] [PATCHv2 2/7] snapshot: virsh snapshot-list and children
Daniel Veillard
veillard at redhat.com
Mon Oct 10 03:16:50 UTC 2011
On Fri, Sep 30, 2011 at 05:09:24PM -0600, Eric Blake wrote:
> Sometimes, we only care about one branch of the snapshot hierarchy.
> Make it easier to list a single branch, by using the new APIs.
>
> Technically, I could emulate these new virsh options on old servers
> by doing a complete dump, then scraping xml to filter out just the
> snapshots that I care about, but I didn't want to do that in this patch.
>
> * tools/virsh.c (cmdSnapshotList): Add --from, --descendants.
> * tools/virsh.pod (snapshot-list): Document them.
> ---
>
> v2: minor rebase cleanups
>
> tools/virsh.c | 76 ++++++++++++++++++++++++++++++++++++++++++++-----------
> tools/virsh.pod | 9 ++++++-
> 2 files changed, 69 insertions(+), 16 deletions(-)
>
> diff --git a/tools/virsh.c b/tools/virsh.c
> index 955b8df..adafe86 100644
> --- a/tools/virsh.c
> +++ b/tools/virsh.c
> @@ -13102,6 +13102,8 @@ static const vshCmdOptDef opts_snapshot_list[] = {
> {"metadata", VSH_OT_BOOL, 0,
> N_("list only snapshots that have metadata that would prevent undefine")},
> {"tree", VSH_OT_BOOL, 0, N_("list snapshots in a tree")},
> + {"from", VSH_OT_DATA, 0, N_("limit list to children of given snapshot")},
> + {"descendants", VSH_OT_BOOL, 0, N_("with --from, list all descendants")},
> {NULL, 0, 0, NULL}
> };
>
> @@ -13128,25 +13130,36 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
> char timestr[100];
> struct tm time_info;
> bool tree = vshCommandOptBool(cmd, "tree");
> + const char *from = NULL;
> + virDomainSnapshotPtr start = NULL;
> +
> + if (vshCommandOptString(cmd, "from", &from) < 0) {
> + vshError(ctl, _("invalid from argument '%s'"), from);
> + goto cleanup;
> + }
>
> if (vshCommandOptBool(cmd, "parent")) {
> if (vshCommandOptBool(cmd, "roots")) {
> vshError(ctl, "%s",
> - _("--parent and --roots are mutually exlusive"));
> + _("--parent and --roots are mutually exclusive"));
> return false;
> }
> if (tree) {
> vshError(ctl, "%s",
> - _("--parent and --tree are mutually exlusive"));
> + _("--parent and --tree are mutually exclusive"));
> return false;
> }
> parent_filter = 1;
> } else if (vshCommandOptBool(cmd, "roots")) {
> if (tree) {
> vshError(ctl, "%s",
> - _("--roots and --tree are mutually exlusive"));
> + _("--roots and --tree are mutually exclusive"));
> return false;
> }
> + if (from) {
> + vshError(ctl, "%s",
> + _("--roots and --from are mutually exclusive"));
> + }
> flags |= VIR_DOMAIN_SNAPSHOT_LIST_ROOTS;
> }
>
> @@ -13161,16 +13174,29 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
> if (dom == NULL)
> goto cleanup;
>
> - numsnaps = virDomainSnapshotNum(dom, flags);
> -
> - /* Fall back to simulation if --roots was unsupported. */
> - if (numsnaps < 0 && last_error->code == VIR_ERR_INVALID_ARG &&
> - (flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS)) {
> - virFreeError(last_error);
> - last_error = NULL;
> - parent_filter = -1;
> - flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_ROOTS;
> + if (from) {
> + start = virDomainSnapshotLookupByName(dom, from, 0);
> + if (!start)
> + goto cleanup;
> + 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? */
> + } else {
> numsnaps = virDomainSnapshotNum(dom, flags);
> +
> + /* Fall back to simulation if --roots was unsupported. */
> + if (numsnaps < 0 && last_error->code == VIR_ERR_INVALID_ARG &&
> + (flags & VIR_DOMAIN_SNAPSHOT_LIST_ROOTS)) {
> + virFreeError(last_error);
> + last_error = NULL;
> + parent_filter = -1;
> + flags &= ~VIR_DOMAIN_SNAPSHOT_LIST_ROOTS;
> + numsnaps = virDomainSnapshotNum(dom, flags);
> + }
> }
>
> if (numsnaps < 0)
> @@ -13196,14 +13222,32 @@ cmdSnapshotList(vshControl *ctl, const vshCmd *cmd)
> if (VIR_ALLOC_N(names, numsnaps) < 0)
> goto cleanup;
>
> - actual = virDomainSnapshotListNames(dom, names, numsnaps, flags);
> + if (from) {
> + /* When mixing --from and --tree, we want to start the tree at the
> + * given snapshot. Without --tree, only list the children. */
> + if (tree) {
> + if (numsnaps)
> + actual = virDomainSnapshotListChildrenNames(start, names + 1,
> + numsnaps - 1,
> + flags);
> + if (actual >= 0) {
> + actual++;
> + names[0] = vshStrdup(ctl, from);
> + }
> + } else {
> + actual = virDomainSnapshotListChildrenNames(start, names,
> + numsnaps, flags);
> + }
> + } else {
> + actual = virDomainSnapshotListNames(dom, names, numsnaps, flags);
> + }
> if (actual < 0)
> goto cleanup;
>
> if (tree) {
> char indentBuf[INDENT_BUFLEN];
> - char **parents = vshMalloc(ctl, sizeof(char *) * actual);
> - for (i = 0; i < actual; i++) {
> + char **parents = vshCalloc(ctl, sizeof(char *), actual);
> + for (i = (from ? 1 : 0); i < actual; i++) {
> /* free up memory from previous iterations of the loop */
> if (snapshot)
> virDomainSnapshotFree(snapshot);
> @@ -13298,6 +13342,8 @@ cleanup:
> VIR_FREE(state);
> if (snapshot)
> virDomainSnapshotFree(snapshot);
> + if (start)
> + virDomainSnapshotFree(start);
> xmlXPathFreeContext(ctxt);
> xmlFreeDoc(xml);
> VIR_FREE(doc);
> diff --git a/tools/virsh.pod b/tools/virsh.pod
> index 1f7c76f..dd60a64 100644
> --- a/tools/virsh.pod
> +++ b/tools/virsh.pod
> @@ -1969,7 +1969,7 @@ The editor used can be supplied by the C<$VISUAL> or C<$EDITOR> environment
> variables, and defaults to C<vi>.
>
> =item B<snapshot-list> I<domain> [{I<--parent> | I<--roots> | I<--tree>}]
> -[I<--metadata>]
> +[I<--metadata>] [[I<--from>] B<snapshot> [I<--descendants>]]
>
> List all of the available snapshots for the given domain, defaulting
> to show columns for the snapshot name, creation time, and domain state.
> @@ -1980,6 +1980,13 @@ the list will be filtered to just snapshots that have no parents.
> If I<--tree> is specified, the output will be in a tree format, listing
> just snapshot names. These three options are mutually exclusive.
>
> +If I<--from> is provided, filter the list to snapshots which are
> +children of the given B<snapshot>. When used in isolation or with
> +I<--parent>, the list is limited to direct children unless
> +I<--descendants> is also present. When used with I<--tree>, the
> +use of I<--descendants> is implied. This option is not compatible
> +with I<--roots>.
> +
> If I<--metadata> is specified, the list will be filtered to just
> snapshots that involve libvirt metadata, and thus would prevent
> B<undefine> of a persistent domain, or be lost on B<destroy> of
ACK,
I'm unsure about the emulation need, except for a server running 0.9.6
and a newer client ...
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel at veillard.com | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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