Re: [libvirt] [PATCH 3/5] snapshot: Support deleting external disk snapshots when deleting

Signed-off-by: Povilas Kanapickas <povilas(a)radix.lt&gt; --- src/qemu/qemu_domain.c | 45 ++++++++++++++++++++++++++++++++++++++---- src/qemu/qemu_driver.c | 7 ++++--- 2 files changed, 45 insertions(+), 7 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index ba3fff607a..73c41788f8 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -8244,6 +8244,38 @@ qemuDomainSnapshotForEachQcow2(virQEMUDriverPtr driver, op, try_all, def->ndisks); } +static int +qemuDomainSnapshotDiscardExternal(virDomainSnapshotObjPtr snap) +{ + int i; + virDomainSnapshotDiskDefPtr snap_disk; + + // FIXME: libvirt stores the VM definition and the list of disks that + // snapshot has been taken of since 0.9.5. Before that we must assume that + // all disks from within the VM definition have been snapshotted and that + // they all were internal disks. Did libvirt support external snapshots + // before 0.9.5? If so, if we ever end up in this code path we may incur + // data loss as we'll delete whole QEMU file thinking it's an external + // snapshot.

+ if (!snap->def->dom) { + virReportError(VIR_ERR_OPERATION_INVALID, + _("Snapshots created using libvirt 9.5 and containing " + "external disk snapshots cannot be safely " + "discarded.")); + return -1; + } + + for (i = 0; i < snap->def->ndisks; ++i) { + snap_disk = &(snap->def->disks[i]); + if (snap_disk->snapshot != VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL) + continue; + if (unlink(snap_disk->src->path) < 0) + VIR_WARN("Failed to unlink snapshot disk '%s'", + snap_disk->src->path);