[PATCH 04/19] qemu: checkpoint: Introduce support for deleting checkpoints accross snapshots
Peter Krempa
pkrempa at redhat.com
Fri Jan 31 14:31:08 UTC 2020
Allow deleting of checkpoints when snapshots were created along. The
code tracks and modifies the checkpoint list so that backups can still
be taken with such a backing chain. This unfortunately requires to
rename few bitmaps (by copying and deleting them) in some cases.
Signed-off-by: Peter Krempa <pkrempa at redhat.com>
---
src/qemu/qemu_checkpoint.c | 112 ++++++++++++++++++++++++++++---------
src/qemu/qemu_checkpoint.h | 5 +-
tests/qemublocktest.c | 34 +++++++----
3 files changed, 111 insertions(+), 40 deletions(-)
diff --git a/src/qemu/qemu_checkpoint.c b/src/qemu/qemu_checkpoint.c
index e75cdd0458..087a740cf8 100644
--- a/src/qemu/qemu_checkpoint.c
+++ b/src/qemu/qemu_checkpoint.c
@@ -24,6 +24,7 @@
#include "qemu_capabilities.h"
#include "qemu_monitor.h"
#include "qemu_domain.h"
+#include "qemu_block.h"
#include "virerror.h"
#include "virlog.h"
@@ -150,39 +151,92 @@ qemuCheckpointFindActiveDiskInParent(virDomainObjPtr vm,
int
qemuCheckpointDiscardDiskBitmaps(virStorageSourcePtr src,
+ virHashTablePtr blockNamedNodeData,
const char *delbitmap,
const char *parentbitmap,
- bool chkcurrent,
- virJSONValuePtr actions)
+ virJSONValuePtr actions,
+ const char *diskdst)
{
- if (parentbitmap) {
- g_autoptr(virJSONValue) arr = NULL;
+ virStorageSourcePtr n = src;
- if (!(arr = virJSONValueNewArray()))
- return -1;
+ /* find the backing chain entry with bitmap named '@bitmap' */
+ while (n) {
+ qemuBlockNamedNodeDataBitmapPtr tmp;
- if (qemuMonitorTransactionBitmapMergeSourceAddBitmap(arr,
- src->nodeformat,
- delbitmap) < 0)
- return -1;
+ if ((tmp = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData,
+ n, delbitmap))) {
+ break;
+ }
+
+ n = n->backingStore;
+ }
+
+ if (!n) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("bitmap '%s' not found in backing chain of '%s'"),
+ delbitmap, diskdst);
+ return -1;
+ }
- if (chkcurrent) {
- if (qemuMonitorTransactionBitmapEnable(actions,
- src->nodeformat,
- parentbitmap) < 0)
+ while (n) {
+ qemuBlockNamedNodeDataBitmapPtr srcbitmap;
+
+ if (!(srcbitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData,
+ n, delbitmap)))
+ break;
+
+ /* For the actual checkpoint deletion we will merge any bitmap into the
+ * bitmap of the parent checkpoint (@mergebitmap) or for any image
+ * where the parent checkpoint bitmap is not present we must rename
+ * the bitmap of the deleted checkpoint into the bitmap of the parent
+ * checkpoint as qemu can't currently take the allocation map and turn
+ * it into a bitmap and thus we wouldn't be able to do a backup. */
+ if (parentbitmap) {
+ qemuBlockNamedNodeDataBitmapPtr dstbitmap;
+ g_autoptr(virJSONValue) arr = NULL;
+
+ dstbitmap = qemuBlockNamedNodeDataGetBitmapByName(blockNamedNodeData,
+ n, parentbitmap);
+
+ if (dstbitmap) {
+ if (srcbitmap->recording && !dstbitmap->recording) {
+ if (qemuMonitorTransactionBitmapEnable(actions,
+ n->nodeformat,
+ dstbitmap->name) < 0)
+ return -1;
+ }
+
+ } else {
+ if (qemuMonitorTransactionBitmapAdd(actions,
+ n->nodeformat,
+ parentbitmap,
+ true,
+ !srcbitmap->recording,
+ srcbitmap->granularity) < 0)
+ return -1;
+ }
+
+ if (!(arr = virJSONValueNewArray()))
+ return -1;
+
+ if (qemuMonitorTransactionBitmapMergeSourceAddBitmap(arr,
+ n->nodeformat,
+ srcbitmap->name) < 0)
+ return -1;
+
+ if (qemuMonitorTransactionBitmapMerge(actions,
+ n->nodeformat,
+ parentbitmap, &arr) < 0)
return -1;
}
- if (qemuMonitorTransactionBitmapMerge(actions,
- src->nodeformat,
- parentbitmap, &arr) < 0)
+ if (qemuMonitorTransactionBitmapRemove(actions,
+ n->nodeformat,
+ srcbitmap->name) < 0)
return -1;
- }
- if (qemuMonitorTransactionBitmapRemove(actions,
- src->nodeformat,
- delbitmap) < 0)
- return -1;
+ n = n->backingStore;
+ }
return 0;
}
@@ -191,11 +245,11 @@ qemuCheckpointDiscardDiskBitmaps(virStorageSourcePtr src,
static int
qemuCheckpointDiscardBitmaps(virDomainObjPtr vm,
virDomainCheckpointDefPtr chkdef,
- bool chkcurrent,
virDomainMomentObjPtr parent)
{
qemuDomainObjPrivatePtr priv = vm->privateData;
virQEMUDriverPtr driver = priv->driver;
+ g_autoptr(virHashTable) blockNamedNodeData = NULL;
int rc;
g_autoptr(virJSONValue) actions = NULL;
size_t i;
@@ -203,6 +257,11 @@ qemuCheckpointDiscardBitmaps(virDomainObjPtr vm,
if (!(actions = virJSONValueNewArray()))
return -1;
+ qemuDomainObjEnterMonitor(driver, vm);
+ blockNamedNodeData = qemuMonitorBlockGetNamedNodeData(priv->mon);
+ if (qemuDomainObjExitMonitor(priv->driver, vm) < 0 || !blockNamedNodeData)
+ return -1;
+
for (i = 0; i < chkdef->ndisks; i++) {
virDomainCheckpointDiskDef *chkdisk = &chkdef->disks[i];
virDomainDiskDefPtr domdisk = virDomainDiskByTarget(vm->def, chkdisk->name);
@@ -223,8 +282,9 @@ qemuCheckpointDiscardBitmaps(virDomainObjPtr vm,
chkdisk->name)))
parentbitmap = parentchkdisk->name;
- if (qemuCheckpointDiscardDiskBitmaps(domdisk->src, chkdisk->bitmap,
- parentbitmap, chkcurrent, actions) < 0)
+ if (qemuCheckpointDiscardDiskBitmaps(domdisk->src, blockNamedNodeData,
+ chkdisk->bitmap, parentbitmap,
+ actions, domdisk->dst) < 0)
return -1;
}
@@ -262,7 +322,7 @@ qemuCheckpointDiscard(virQEMUDriverPtr driver,
virDomainCheckpointDefPtr chkdef = virDomainCheckpointObjGetDef(chk);
parent = virDomainCheckpointFindByName(vm->checkpoints,
chk->def->parent_name);
- if (qemuCheckpointDiscardBitmaps(vm, chkdef, chkcurrent, parent) < 0)
+ if (qemuCheckpointDiscardBitmaps(vm, chkdef, parent) < 0)
return -1;
}
diff --git a/src/qemu/qemu_checkpoint.h b/src/qemu/qemu_checkpoint.h
index 85fd453d50..976b1eed0f 100644
--- a/src/qemu/qemu_checkpoint.h
+++ b/src/qemu/qemu_checkpoint.h
@@ -74,7 +74,8 @@ qemuCheckpointRollbackMetadata(virDomainObjPtr vm,
int
qemuCheckpointDiscardDiskBitmaps(virStorageSourcePtr src,
+ virHashTablePtr blockNamedNodeData,
const char *delbitmap,
const char *parentbitmap,
- bool chkcurrent,
- virJSONValuePtr actions);
+ virJSONValuePtr actions,
+ const char *diskdst);
diff --git a/tests/qemublocktest.c b/tests/qemublocktest.c
index 861b4e86ae..6194c45ec8 100644
--- a/tests/qemublocktest.c
+++ b/tests/qemublocktest.c
@@ -708,6 +708,7 @@ struct testQemuCheckpointDeleteMergeData {
virStorageSourcePtr chain;
const char *deletebitmap;
const char *parentbitmap;
+ const char *nodedatafile;
};
@@ -718,22 +719,30 @@ testQemuCheckpointDeleteMerge(const void *opaque)
g_autofree char *actual = NULL;
g_autofree char *expectpath = NULL;
g_autoptr(virJSONValue) actions = NULL;
- bool currentcheckpoint;
+ g_autoptr(virJSONValue) nodedatajson = NULL;
+ g_autoptr(virHashTable) nodedata = NULL;
expectpath = g_strdup_printf("%s/%s%s-out.json", abs_srcdir,
checkpointDeletePrefix, data->name);
- if (!(actions = virJSONValueNewArray()))
+ if (!(nodedatajson = virTestLoadFileJSON(bitmapDetectPrefix, data->nodedatafile,
+ ".json", NULL)))
return -1;
- /* hack to get the 'current' state until the function stops accepting it */
- currentcheckpoint = STREQ("current", data->deletebitmap);
+ if (!(nodedata = qemuMonitorJSONBlockGetNamedNodeDataJSON(nodedatajson))) {
+ VIR_TEST_VERBOSE("failed to load nodedata JSON\n");
+ return -1;
+ }
+
+ if (!(actions = virJSONValueNewArray()))
+ return -1;
if (qemuCheckpointDiscardDiskBitmaps(data->chain,
+ nodedata,
data->deletebitmap,
data->parentbitmap,
- currentcheckpoint,
- actions) < 0) {
+ actions,
+ "testdisk") < 0) {
VIR_TEST_VERBOSE("failed to generate checkpoint delete transaction\n");
return -1;
}
@@ -992,22 +1001,23 @@ mymain(void)
TEST_BACKUP_BITMAP_CALCULATE("snapshot-intermediate", bitmapSourceChain, "d", "snapshots");
TEST_BACKUP_BITMAP_CALCULATE("snapshot-deep", bitmapSourceChain, "a", "snapshots");
-#define TEST_CHECKPOINT_DELETE_MERGE(testname, delbmp, parbmp) \
+#define TEST_CHECKPOINT_DELETE_MERGE(testname, delbmp, parbmp, named) \
do { \
checkpointdeletedata.name = testname; \
checkpointdeletedata.chain = bitmapSourceChain; \
checkpointdeletedata.deletebitmap = delbmp; \
checkpointdeletedata.parentbitmap = parbmp; \
+ checkpointdeletedata.nodedatafile = named; \
if (virTestRun("checkpoint delete " testname, \
testQemuCheckpointDeleteMerge, &checkpointdeletedata) < 0) \
ret = -1; \
} while (0)
- TEST_CHECKPOINT_DELETE_MERGE("basic-noparent", "a", NULL);
- TEST_CHECKPOINT_DELETE_MERGE("basic-intermediate1", "b", "a");
- TEST_CHECKPOINT_DELETE_MERGE("basic-intermediate2", "c", "b");
- TEST_CHECKPOINT_DELETE_MERGE("basic-intermediate3", "d", "c");
- TEST_CHECKPOINT_DELETE_MERGE("basic-current", "current", "d");
+ TEST_CHECKPOINT_DELETE_MERGE("basic-noparent", "a", NULL, "basic");
+ TEST_CHECKPOINT_DELETE_MERGE("basic-intermediate1", "b", "a", "basic");
+ TEST_CHECKPOINT_DELETE_MERGE("basic-intermediate2", "c", "b", "basic");
+ TEST_CHECKPOINT_DELETE_MERGE("basic-intermediate3", "d", "c", "basic");
+ TEST_CHECKPOINT_DELETE_MERGE("basic-current", "current", "d", "basic");
cleanup:
virHashFree(diskxmljsondata.schema);
--
2.24.1
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