Re: [PATCH v3 5/6] qemu: Introduce to handle transient disk
On Thu, Sep 17, 2020 at 09:30:44 -0400, Masayoshi Mizuma wrote:
> From: Masayoshi Mizuma
>
> Here is the implementation of transient option for qcow2 and raw format
> disk. This gets available directive in domain xml file
> like as:
>
>
>
>
>
>
>
>
> When the qemu command line options are built, a new qcow2 image is
> created with backing qcow2 by using blockdev-snapshot command.
> The backing image is the qcow2 file which is set as .
> The filename of the new qcow2 image is original-source-file.TRANSIENT.
>
> Signed-off-by: Masayoshi Mizuma
> ---
> src/qemu/qemu_snapshot.c | 103 +++---
> src/qemu/qemu_snapshot.h | 5 ++
> src/util/virstoragefile.c | 2 +
> src/util/virstoragefile.h | 4 ++
> 4 files changed, 107 insertions(+), 7 deletions(-)
>
> diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
> index 1e8ea80b22..67fdc488e0 100644
> --- a/src/qemu/qemu_snapshot.c
> +++ b/src/qemu/qemu_snapshot.c
> @@ -1158,7 +1158,8 @@ qemuSnapshotCreateDiskActive(virQEMUDriverPtr driver,
> virHashTablePtr blockNamedNodeData,
> unsigned int flags,
> virQEMUDriverConfigPtr cfg,
> - qemuDomainAsyncJob asyncJob)
> + qemuDomainAsyncJob asyncJob,
> + bool domSave)
> {
> qemuDomainObjPrivatePtr priv = vm->privateData;
> g_autoptr(virJSONValue) actions = NULL;
> @@ -1201,17 +1202,26 @@ qemuSnapshotCreateDiskActive(virQEMUDriverPtr driver,
>
> virDomainAuditDisk(vm, dd->disk->src, dd->src, "snapshot", rc >= 0);
>
> -if (rc == 0)
> +if (rc == 0) {
> qemuSnapshotDiskUpdateSource(driver, vm, dd, blockdev);
> +
> +if (dd->disk->transient) {
> +/* Mark the transient working is completed to make sure we
> can */
> +/* remove the transient disk when the guest is shutdown. */
> +dd->disk->src->transientEstablished = true;
> +}
> +}
> }
>
> if (rc < 0)
> goto cleanup;
>
> -if (virDomainObjSave(vm, driver->xmlopt, cfg->stateDir) < 0 ||
> -(vm->newDef && virDomainDefSave(vm->newDef, driver->xmlopt,
> -cfg->configDir) < 0))
> -goto cleanup;
> +if (domSave) {
> +if (virDomainObjSave(vm, driver->xmlopt, cfg->stateDir) < 0 ||
> +(vm->newDef && virDomainDefSave(vm->newDef, driver->xmlopt,
> +cfg->configDir) < 0))
> +goto cleanup;
> +}
>
> ret = 0;
>
> @@ -1349,7 +1359,7 @@ qemuSnapshotCreateActiveExternal(virQEMUDriverPtr
> driver,
>
> if ((ret = qemuSnapshotCreateDiskActive(driver, vm, snap,
> blockNamedNodeData, flags, cfg,
> -QEMU_ASYNC_JOB_SNAPSHOT)) < 0)
> +QEMU_ASYNC_JOB_SNAPSHOT, true))
> < 0)
> goto cleanup;
>
> /* the snapshot is complete now */
> @@ -2264,3 +2274,82 @@ qemuSnapshotDelete(virDomainObjPtr vm,
> cleanup:
> return ret;
> }
> +
> +
> +static int
> +qemuSnapshotSetupTransientDisk(virDomainSnapshotDiskDefPtr def,
> + virStorageSourcePtr src)
> +{
> +g_autoptr(virStorageSource) trans = NULL;
> +
> +if (!(trans = virStorageSourceNew()))
> +return -1;
> +
> +trans->path = g_strdup_printf("%s.TRANSIENT", src->path);
> +if (virFileExists(trans->path)) {
> +virReportError(VIR_ERR_INVALID_ARG,
> + _("Transient disk '%s' for '%s' exists"),
> + trans->path, src->path);
> +return -1;
> +}
> +
> +trans->type = VIR_STORAGE_TYPE_FILE;
> +trans->format = VIR_STORAGE_FILE_QCOW2;
> +
> +def->src = g_steal_pointer(&trans);
> +
> +return 0;
> +}
> +
> +
> +int
> +qemuSnapshotCreateTransientDisk(virQEMUDriverPtr driver,
> +virDomainObjPtr vm,
> +int asyncJob)
> +{
> +int rc;
> +size_t i;
> +virDomainMomentObjPtr snap = NULL;
> +g_autoptr(virDomainSnapshotDef) snapdef = NULL;
> +g_autoptr(virHashTable) blockNamedNodeData = NULL;
> +qemuDomainObjPrivatePtr priv = vm->privateData;
> +g_autoptr(virQEMUDriverConfig) cfg =
> virQEMUDriverGetConfig(priv->driver);
> +
> +if (!(snapdef = virDomainSnapshotDefNew()))
> +return -1;
This shouldn't be necessary if you factor out stuff out of
qemuSnapshotCreateDiskActive. I'll send a prerequisite patch doing the
refactor as I've requested last time.
> +
> +snapdef->parent.name = g_strdup_printf("transient");
> +
> +snapdef->ndisks = vm->def->ndisks;
> +if (VIR_ALLOC_N(snapdef->disks, snapdef->ndisks) < 0)
> +retur
[PATCH v3 5/6] qemu: Introduce to handle transient disk
From: Masayoshi Mizuma
Here is the implementation of transient option for qcow2 and raw format
disk. This gets available directive in domain xml file
like as:
When the qemu command line options are built, a new qcow2 image is
created with backing qcow2 by using blockdev-snapshot command.
The backing image is the qcow2 file which is set as .
The filename of the new qcow2 image is original-source-file.TRANSIENT.
Signed-off-by: Masayoshi Mizuma
---
src/qemu/qemu_snapshot.c | 103 +++---
src/qemu/qemu_snapshot.h | 5 ++
src/util/virstoragefile.c | 2 +
src/util/virstoragefile.h | 4 ++
4 files changed, 107 insertions(+), 7 deletions(-)
diff --git a/src/qemu/qemu_snapshot.c b/src/qemu/qemu_snapshot.c
index 1e8ea80b22..67fdc488e0 100644
--- a/src/qemu/qemu_snapshot.c
+++ b/src/qemu/qemu_snapshot.c
@@ -1158,7 +1158,8 @@ qemuSnapshotCreateDiskActive(virQEMUDriverPtr driver,
virHashTablePtr blockNamedNodeData,
unsigned int flags,
virQEMUDriverConfigPtr cfg,
- qemuDomainAsyncJob asyncJob)
+ qemuDomainAsyncJob asyncJob,
+ bool domSave)
{
qemuDomainObjPrivatePtr priv = vm->privateData;
g_autoptr(virJSONValue) actions = NULL;
@@ -1201,17 +1202,26 @@ qemuSnapshotCreateDiskActive(virQEMUDriverPtr driver,
virDomainAuditDisk(vm, dd->disk->src, dd->src, "snapshot", rc >= 0);
-if (rc == 0)
+if (rc == 0) {
qemuSnapshotDiskUpdateSource(driver, vm, dd, blockdev);
+
+if (dd->disk->transient) {
+/* Mark the transient working is completed to make sure we can
*/
+/* remove the transient disk when the guest is shutdown. */
+dd->disk->src->transientEstablished = true;
+}
+}
}
if (rc < 0)
goto cleanup;
-if (virDomainObjSave(vm, driver->xmlopt, cfg->stateDir) < 0 ||
-(vm->newDef && virDomainDefSave(vm->newDef, driver->xmlopt,
-cfg->configDir) < 0))
-goto cleanup;
+if (domSave) {
+if (virDomainObjSave(vm, driver->xmlopt, cfg->stateDir) < 0 ||
+(vm->newDef && virDomainDefSave(vm->newDef, driver->xmlopt,
+cfg->configDir) < 0))
+goto cleanup;
+}
ret = 0;
@@ -1349,7 +1359,7 @@ qemuSnapshotCreateActiveExternal(virQEMUDriverPtr driver,
if ((ret = qemuSnapshotCreateDiskActive(driver, vm, snap,
blockNamedNodeData, flags, cfg,
-QEMU_ASYNC_JOB_SNAPSHOT)) < 0)
+QEMU_ASYNC_JOB_SNAPSHOT, true)) <
0)
goto cleanup;
/* the snapshot is complete now */
@@ -2264,3 +2274,82 @@ qemuSnapshotDelete(virDomainObjPtr vm,
cleanup:
return ret;
}
+
+
+static int
+qemuSnapshotSetupTransientDisk(virDomainSnapshotDiskDefPtr def,
+ virStorageSourcePtr src)
+{
+g_autoptr(virStorageSource) trans = NULL;
+
+if (!(trans = virStorageSourceNew()))
+return -1;
+
+trans->path = g_strdup_printf("%s.TRANSIENT", src->path);
+if (virFileExists(trans->path)) {
+virReportError(VIR_ERR_INVALID_ARG,
+ _("Transient disk '%s' for '%s' exists"),
+ trans->path, src->path);
+return -1;
+}
+
+trans->type = VIR_STORAGE_TYPE_FILE;
+trans->format = VIR_STORAGE_FILE_QCOW2;
+
+def->src = g_steal_pointer(&trans);
+
+return 0;
+}
+
+
+int
+qemuSnapshotCreateTransientDisk(virQEMUDriverPtr driver,
+virDomainObjPtr vm,
+int asyncJob)
+{
+int rc;
+size_t i;
+virDomainMomentObjPtr snap = NULL;
+g_autoptr(virDomainSnapshotDef) snapdef = NULL;
+g_autoptr(virHashTable) blockNamedNodeData = NULL;
+qemuDomainObjPrivatePtr priv = vm->privateData;
+g_autoptr(virQEMUDriverConfig) cfg = virQEMUDriverGetConfig(priv->driver);
+
+if (!(snapdef = virDomainSnapshotDefNew()))
+return -1;
+
+snapdef->parent.name = g_strdup_printf("transient");
+
+snapdef->ndisks = vm->def->ndisks;
+if (VIR_ALLOC_N(snapdef->disks, snapdef->ndisks) < 0)
+return -1;
+
+for (i = 0; i < vm->def->ndisks; i++) {
+virDomainDiskDefPtr disk = vm->def->disks[i];
+virDomainSnapshotDiskDefPtr snapdisk = &(snapdef->disks[i]);
+
+if (disk->transient) {
+if ((rc = qemuSnapshotSetupTransientDisk(snapdisk, disk->src)) < 0)
+return -1;
+
+} else {
+snapdisk->snapshot = VIR_DOMAIN_SNAPSHOT_LOCATION_NONE;
+}
+}
+
+if (!(snap = virDomainSnapshotAssignDef(vm->snapshots, snapdef)))
+re
