[libvirt] [PATCH 7/7] snapshot: Add VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE_LIST flag

[Eric Blake]

On 2/20/19 9:53 AM, Eric Blake wrote:
> Continue the work of the previous patch in making it possible
> to copy the state of a transient domain with snapshots from one
> host to another, by allowing the destination to perform bulk
> redefines.  Note that the destination still has to do separate
> calls for creating/defining the domain first, and then redefining
> the snapshots (that is, there is intentional asymmetry between
> dumping the list in virDomainGetXMLDesc() but redefining it via
> virDomainSnapshotCreateXML()), but this is better than the
> previous state of having to make multiple REDEFINE calls.  The
> bulk flag requires no pre-existing snapshot metadata (as that
> makes life much easier if there is a failure encountered partway
> through the list processing - simply remove all other snapshot
> metadatas), and makes no guarantees on which snapshot (when there
> are multiple) will actually be returned.
> 
> Wire up the virsh snapshot-create command to support the new flag.
> 
> Actual driver implementations will be in later patches.
> 
> Signed-off-by: Eric Blake <eblake at redhat.com>
> ---
>  include/libvirt/libvirt-domain-snapshot.h |  3 +++
>  src/libvirt-domain-snapshot.c             | 21 ++++++++++++++++++---
>  tools/virsh-snapshot.c                    | 13 +++++++++++++
>  3 files changed, 34 insertions(+), 3 deletions(-)
> 

For convenience, I'll probably squash this in (while the API requires
both REDEFINE and REDEFINE_LIST flags, the virsh tooling can imply one
from the other):

diff --git a/tools/virsh-snapshot.c b/tools/virsh-snapshot.c
index f6efadde2d..a58731c46e 100644
--- a/tools/virsh-snapshot.c
+++ b/tools/virsh-snapshot.c
@@ -131,7 +131,7 @@ static const vshCmdOptDef opts_snapshot_create[] = {
     VIRSH_COMMON_OPT_CURRENT(N_("with redefine, set current snapshot")),
     {.name = "redefine-list",
      .type = VSH_OT_BOOL,
-     .help = N_("with redefine, bulk define a set of snapshots"),
+     .help = N_("bulk define a set of snapshots, implies --redefine"),
     },
     {.name = "no-metadata",
      .type = VSH_OT_BOOL,
@@ -189,7 +189,8 @@ cmdSnapshotCreate(vshControl *ctl, const vshCmd *cmd)
     if (vshCommandOptBool(cmd, "live"))
         flags |= VIR_DOMAIN_SNAPSHOT_CREATE_LIVE;
     if (vshCommandOptBool(cmd, "redefine-list"))
-        flags |= VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE_LIST;
+        flags |= VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE |
+            VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE_LIST;

     if (!(dom = virshCommandOptDomain(ctl, cmd, NULL)))
         goto cleanup;


-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org