Re: [libvirt] [PATCH 5/5] snapshot: Support reparenting external disk snapshots when deleting

Signed-off-by: Povilas Kanapickas <povilas(a)radix.lt&gt; --- src/qemu/qemu_driver.c | 89 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 227ec1c6d9..a3ffc19122 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c

@@ -16617,6 +16618,88 @@ qemuDomainSnapshotReparentChildrenMetadata(virDomainSnapshotObjPtr snap, rep->cfg->snapshotDir); } +static int +qemuDomainSnapshotReparentDiskExternal(virQEMUDriverPtr driver, + virDomainSnapshotObjPtr parent_snap, + virDomainSnapshotDiskDefPtr disk) +{ + const char* qemu_img_path = NULL; + virCommandPtr cmd = NULL; + int i; + int ret = -1; + const char* parent_disk_path = NULL; + + // Find the path to the disk we should use as the base when reparenting + // FIXME: what if there's no parent snapshot? i.e. we need to reparent on + // "empty" disk? + for (i = 0; i < parent_snap->def->dom->ndisks; ++i) { + if (STREQ(parent_snap->def->dom->disks[i]->dst, disk->name)) { + parent_disk_path = parent_snap->def->dom->disks[i]->src->path; + break; + } + } + + if (parent_disk_path == NULL) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Could not find disk to reparent '%s' to"), + disk->src->path); + goto cleanup; + } + + if (!(qemu_img_path = qemuFindQemuImgBinary(driver))) { + goto cleanup; + } + + if (!(cmd = virCommandNewArgList(qemu_img_path, + "rebase", "-b", parent_disk_path, + disk->src->path, + NULL))) {

+ goto cleanup; + } + + if (virCommandRun(cmd, NULL) < 0) + goto cleanup; + + ret = 0; +cleanup: + virCommandFree(cmd); + return ret; +} + +static int +qemuDomainSnapshotReparentDisks(virDomainSnapshotObjPtr snap, + virQEMUSnapReparentPtr rep) +{ + int i; + virDomainSnapshotDiskDefPtr snap_disk; + + if (!snap->def->dom) { + VIR_WARN("Any external disk snapshots in a snapshot created with " + "pre-0.9.5 libvirt will not be correctly reparented."); + // In snapshots created with pre-0.9.5 libvirt we don't have information + // needed to correctly reparent external disk snapshots but we also + // don't even know whether external disk snapshots were used so that + // we could report this as an error. We can only emit a warning in that + // case.