On a Friday in 2021, Peter Krempa wrote:
>The code will be later reused when adding support for sharing the
>backing image of the snapshot.
>
>Signed-off-by: Peter Krempa <pkrempa@redhat.com>
>---
> src/qemu/qemu_snapshot.c | 40 ++++++++++++++++++++++++++--------------
> 1 file changed, 26 insertions(+), 14 deletions(-)
>
>diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
>index fd6669433b..c3cff46bc9 100644
>--- a/src/qemu/qemu_snapshot.c
>+++ b/src/qemu/qemu_snapshot.c
>@@ -1168,6 +1168,29 @@ qemuSnapshotDiskPrepareActiveExternal(virDomainObj *vm,
> }
>
>
>+static virDomainSnapshotDiskDef *
>+qemuSnapshotGetTransientDiskDef(virDomainDiskDef *domdisk)
>+{
>+ g_autoptr(virDomainSnapshotDiskDef) snapdisk = g_new0(virDomainSnapshotDiskDef, 1);
>+
>+ snapdisk->name = g_strdup(domdisk->dst);
>+ snapdisk->snapshot = VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL;
>+ snapdisk->src = virStorageSourceNew();
>+ snapdisk->src->type = VIR_STORAGE_TYPE_FILE;
>+ snapdisk->src->format = VIR_STORAGE_FILE_QCOW2;
>+ snapdisk->src->path = g_strdup_printf("%s.TRANSIENT", domdisk->src->path);
>+
>+ if (virFileExists(snapdisk->src->path)) {
>+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
>+ _("Overlay file '%s' for transient disk '%s' already exists"),
>+ snapdisk->src->path, domdisk->dst);
>+ return NULL;
>+ }
>+
>+ return g_steal_pointer(&snapdisk);
>+}
>+
>+
> static qemuSnapshotDiskContext *
> qemuSnapshotDiskPrepareDisksTransient(virDomainObj *vm,
> virQEMUDriverConfig *cfg,
>@@ -1181,26 +1204,15 @@ qemuSnapshotDiskPrepareDisksTransient(virDomainObj *vm,
>
> for (i = 0; i < vm->def->ndisks; i++) {
> virDomainDiskDef *domdisk = vm->def->disks[i];
>- g_autoptr(virDomainSnapshotDiskDef) snapdisk = g_new0(virDomainSnapshotDiskDef, 1);
>+ g_autoptr(virDomainSnapshotDiskDef) snapdisk = NULL;
>
> if (!domdisk->transient)
> continue;
>
> /* validation code makes sure that we do this only for local disks
> * with a file source */
>- snapdisk->name = g_strdup(domdisk->dst);
>- snapdisk->snapshot = VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL;
>- snapdisk->src = virStorageSourceNew();
>- snapdisk->src->type = VIR_STORAGE_TYPE_FILE;
>- snapdisk->src->format = VIR_STORAGE_FILE_QCOW2;
>- snapdisk->src->path = g_strdup_printf("%s.TRANSIENT", domdisk->src->path);
>-
>- if (virFileExists(snapdisk->src->path)) {
>- virReportError(VIR_ERR_OPERATION_UNSUPPORTED,
>- _("Overlay file '%s' for transient disk '%s' already exists"),
>- snapdisk->src->path, domdisk->dst);
>- return NULL;
>- }
>+
>+ snapdisk = qemuSnapshotGetTransientDiskDef(domdisk);
>
if (!snapdisk)
return NULL;
To correctly propagate the error and avoid NULL dereference below
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Jano
> if (qemuSnapshotDiskPrepareOne(vm, cfg, domdisk, snapdisk,
> snapctxt->dd + snapctxt->ndd++,
>--
>2.31.1
>