[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

Re: [libvirt] [PATCHv2 2/7] snapshot: virsh snapshot-list and children



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 veillard com  | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library  http://libvirt.org/


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]