[libvirt] [PATCH 3/5] snapshot: Support deleting external disk snapshots when deleting
Signed-off-by: Povilas Kanapickas <povilas(a)radix.lt>
---
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);
+ }
+ return 0;
+}
+
/* Discard one snapshot (or its metadata), without reparenting any children. */
int
qemuDomainSnapshotDiscard(virQEMUDriverPtr driver,
@@ -8260,10 +8292,15 @@ qemuDomainSnapshotDiscard(virQEMUDriverPtr driver,
if (!metadata_only) {
if (!virDomainObjIsActive(vm)) {
- /* Ignore any skipped disks */
- if (qemuDomainSnapshotForEachQcow2(driver, vm, snap, "-d",
- true) < 0)
- goto cleanup;
+ if (virDomainSnapshotIsExternal(snap)) {
+ if (qemuDomainSnapshotDiscardExternal(snap) < 0)
+ goto cleanup;
+ } else {
+ /* Ignore any skipped disks */
+ if (qemuDomainSnapshotForEachQcow2(driver, vm, snap, "-d",
+ true) < 0)
+ goto cleanup;
+ }
} else {
priv = vm->privateData;
qemuDomainObjEnterMonitor(driver, vm);
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index eb104d306b..7cd44d6957 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -16662,7 +16662,7 @@ qemuDomainSnapshotDelete(virDomainSnapshotPtr snapshot,
if (!(snap = qemuSnapObjFromSnapshot(vm, snapshot)))
goto endjob;
- if (!metadata_only) {
+ if (!metadata_only && virDomainObjIsActive(vm)) {
if (!(flags & VIR_DOMAIN_SNAPSHOT_DELETE_CHILDREN_ONLY) &&
virDomainSnapshotIsExternal(snap))
external++;
@@ -16673,8 +16673,9 @@ qemuDomainSnapshotDelete(virDomainSnapshotPtr snapshot,
&external);
if (external) {
virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
- _("deletion of %d external disk snapshots not "
- "supported yet"), external);
+ _("deletion of %d external disk snapshots while the
"
+ "domain is active is not supported yet"),
+ external);
goto endjob;
}
}
--
2.17.1