qemu: snapshot: Densely pack data in qemuDomainSnapshotDiskDataCollect

The function skips disks which are not selected for snapshot. Rather
than creating a sparse array and check whether the given field is filled
compress the entries.

Note that this does not allocate a smaller array, but the memory
allocation is short-lived.

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
This commit is contained in:
Peter Krempa 2019-06-05 14:24:25 +02:00
parent 9678503088
commit f34397e51c

View File

@ -15071,37 +15071,42 @@ qemuDomainSnapshotDiskDataFree(qemuDomainSnapshotDiskDataPtr data,
* Collects and prepares a list of structures that hold information about disks
* that are selected for the snapshot.
*/
static qemuDomainSnapshotDiskDataPtr
static int
qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
virDomainObjPtr vm,
virDomainMomentObjPtr snap,
bool reuse)
bool reuse,
qemuDomainSnapshotDiskDataPtr *rdata,
size_t *rndata)
{
size_t i;
qemuDomainSnapshotDiskDataPtr ret;
qemuDomainSnapshotDiskDataPtr data;
size_t ndata = 0;
qemuDomainSnapshotDiskDataPtr dd;
char *backingStoreStr;
virDomainSnapshotDefPtr snapdef = virDomainSnapshotObjGetDef(snap);
int ret = -1;
if (VIR_ALLOC_N(ret, snapdef->ndisks) < 0)
return NULL;
if (VIR_ALLOC_N(data, snapdef->ndisks) < 0)
return -1;
for (i = 0; i < snapdef->ndisks; i++) {
if (snapdef->disks[i].snapshot == VIR_DOMAIN_SNAPSHOT_LOCATION_NONE)
continue;
dd = ret + i;
ndata++;
dd = data + ndata;
dd->disk = vm->def->disks[i];
if (!(dd->src = virStorageSourceCopy(snapdef->disks[i].src, false)))
goto error;
goto cleanup;
if (virStorageSourceInitChainElement(dd->src, dd->disk->src, false) < 0)
goto error;
goto cleanup;
if (qemuDomainStorageFileInit(driver, vm, dd->src, NULL) < 0)
goto error;
goto cleanup;
dd->initialized = true;
@ -15109,7 +15114,7 @@ qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
* block commit still works */
if (reuse) {
if (virStorageFileGetBackingStoreStr(dd->src, &backingStoreStr) < 0)
goto error;
goto cleanup;
if (backingStoreStr != NULL) {
if (virStorageIsRelative(backingStoreStr))
VIR_STEAL_PTR(dd->relPath, backingStoreStr);
@ -15127,19 +15132,21 @@ qemuDomainSnapshotDiskDataCollect(virQEMUDriverPtr driver,
false))) {
if (!(dd->persistsrc = virStorageSourceCopy(dd->src, false)))
goto error;
goto cleanup;
if (virStorageSourceInitChainElement(dd->persistsrc,
dd->persistdisk->src, false) < 0)
goto error;
goto cleanup;
}
}
return ret;
VIR_STEAL_PTR(*rdata, data);
*rndata = ndata;
ret = 0;
error:
qemuDomainSnapshotDiskDataFree(ret, snapdef->ndisks, driver, vm);
return NULL;
cleanup:
qemuDomainSnapshotDiskDataFree(data, ndata, driver, vm);
return ret;
}
@ -15163,9 +15170,6 @@ qemuDomainSnapshotUpdateDiskSourcesRenumber(virStorageSourcePtr src)
static void
qemuDomainSnapshotUpdateDiskSources(qemuDomainSnapshotDiskDataPtr dd)
{
if (!dd->src)
return;
/* storage driver access won'd be needed */
if (dd->initialized)
virStorageFileDeinit(dd->src);
@ -15233,8 +15237,8 @@ qemuDomainSnapshotCreateDiskActive(virQEMUDriverPtr driver,
size_t i;
bool reuse = (flags & VIR_DOMAIN_SNAPSHOT_CREATE_REUSE_EXT) != 0;
qemuDomainSnapshotDiskDataPtr diskdata = NULL;
size_t ndiskdata = 0;
virErrorPtr orig_err = NULL;
virDomainSnapshotDefPtr snapdef = virDomainSnapshotObjGetDef(snap);
if (virDomainObjCheckActive(vm) < 0)
return -1;
@ -15244,17 +15248,15 @@ qemuDomainSnapshotCreateDiskActive(virQEMUDriverPtr driver,
/* prepare a list of objects to use in the vm definition so that we don't
* have to roll back later */
if (!(diskdata = qemuDomainSnapshotDiskDataCollect(driver, vm, snap, reuse)))
if (qemuDomainSnapshotDiskDataCollect(driver, vm, snap, reuse,
&diskdata, &ndiskdata) < 0)
goto cleanup;
/* Based on earlier qemuDomainSnapshotPrepare, all disks in this list are
* now either VIR_DOMAIN_SNAPSHOT_LOCATION_NONE, or
* VIR_DOMAIN_SNAPSHOT_LOCATION_EXTERNAL with a valid file name and
* qcow2 format. */
for (i = 0; i < snapdef->ndisks; i++) {
if (!diskdata[i].src)
continue;
for (i = 0; i < ndiskdata; i++) {
ret = qemuDomainSnapshotCreateSingleDiskActive(driver, vm,
&diskdata[i],
actions, reuse);
@ -15274,12 +15276,9 @@ qemuDomainSnapshotCreateDiskActive(virQEMUDriverPtr driver,
if (qemuDomainObjExitMonitor(driver, vm) < 0)
ret = -1;
for (i = 0; i < snapdef->ndisks; i++) {
for (i = 0; i < ndiskdata; i++) {
qemuDomainSnapshotDiskDataPtr dd = &diskdata[i];
if (!dd->src)
continue;
virDomainAuditDisk(vm, dd->disk->src, dd->src, "snapshot", ret >= 0);
if (ret == 0)
@ -15293,10 +15292,7 @@ qemuDomainSnapshotCreateDiskActive(virQEMUDriverPtr driver,
error:
if (ret < 0) {
virErrorPreserveLast(&orig_err);
for (i = 0; i < snapdef->ndisks; i++) {
if (!diskdata[i].src)
continue;
for (i = 0; i < ndiskdata; i++) {
if (diskdata[i].prepared)
qemuDomainStorageSourceAccessRevoke(driver, vm, diskdata[i].src);
@ -15310,10 +15306,7 @@ qemuDomainSnapshotCreateDiskActive(virQEMUDriverPtr driver,
* stopped using them*/
bool paused = virDomainObjGetState(vm, NULL) != VIR_DOMAIN_RUNNING;
for (i = 0; i < snapdef->ndisks; i++) {
if (!diskdata[i].disk)
continue;
for (i = 0; i < ndiskdata; i++) {
if (paused)
virDomainLockImageDetach(driver->lockManager, vm,
diskdata[i].disk->src);
@ -15329,7 +15322,7 @@ qemuDomainSnapshotCreateDiskActive(virQEMUDriverPtr driver,
ret = -1;
cleanup:
qemuDomainSnapshotDiskDataFree(diskdata, snapdef->ndisks, driver, vm);
qemuDomainSnapshotDiskDataFree(diskdata, ndiskdata, driver, vm);
virErrorRestore(&orig_err);
return ret;