Similarly to the domain config code it may be beneficial to control the
cache size of images introduced as snapshots into the backing chain.
Wire up handling of the 'metadata_cache' element.
Signed-off-by: Peter Krempa <pkrempa@xxxxxxxxxx>
---
docs/formatsnapshot.html.in | 4 ++++
docs/schemas/domainsnapshot.rng | 10 +++++++-
src/conf/snapshot_conf.c | 23 ++++++++++++++++++-
.../qcow2-metadata-cache.xml | 14 +++++++++++
.../qcow2-metadata-cache.xml | 18 +++++++++++++++
tests/qemudomainsnapshotxml2xmltest.c | 3 +++
6 files changed, 70 insertions(+), 2 deletions(-)
create mode 100644 tests/qemudomainsnapshotxml2xmlin/qcow2-metadata-cache.xml
create mode 100644 tests/qemudomainsnapshotxml2xmlout/qcow2-metadata-cache.xml
diff --git a/docs/formatsnapshot.html.in b/docs/formatsnapshot.html.in
index d640deb86d..e481284aa8 100644
--- a/docs/formatsnapshot.html.in
+++ b/docs/formatsnapshot.html.in
@@ -186,6 +186,10 @@
with an attribute <code>type</code> giving the driver type (such
as qcow2), of the new file created by the external
snapshot of the new file.
+
+ Optionally <code>metadata_cache</code> sub-element can be used
+ with same semantics as the identically named subelement of the
+ domain definition disk's driver.
</dd>
<dt><code>seclabel</code></dt>
</dl>
diff --git a/docs/schemas/domainsnapshot.rng b/docs/schemas/domainsnapshot.rng
index e1fb4f7cea..58c370878d 100644
--- a/docs/schemas/domainsnapshot.rng
+++ b/docs/schemas/domainsnapshot.rng
@@ -212,7 +212,15 @@
<ref name="storageFormatBacking"/>
</attribute>
</optional>
- <empty/>
+ <optional>
+ <element name="metadata_cache">
+ <optional>
+ <element name="max_size">
+ <ref name="scaledInteger"/>
+ </element>
+ </optional>
+ </element>
+ </optional>
</element>
</optional>
</define>
diff --git a/src/conf/snapshot_conf.c b/src/conf/snapshot_conf.c
index 757af681cd..673282be7a 100644
--- a/src/conf/snapshot_conf.c
+++ b/src/conf/snapshot_conf.c
@@ -190,6 +190,12 @@ virDomainSnapshotDiskDefParseXML(xmlNodePtr node,
goto cleanup;
}
+ if (virParseScaledValue("./driver/metadata_cache/max_size", NULL,
+ ctxt,
+ &def->src->metadataCacheMaxSize,
+ 1, ULLONG_MAX, false) < 0)
+ goto cleanup;
+
/* validate that the passed path is absolute */
if (virStorageSourceIsRelative(def->src)) {
virReportError(VIR_ERR_XML_ERROR,
@@ -784,12 +790,27 @@ virDomainSnapshotDiskDefFormat(virBufferPtr buf,
virDomainSnapshotLocationTypeToString(disk->snapshot));
if (disk->src->path || disk->src->format != 0) {
+ g_auto(virBuffer) driverAttrBuf = VIR_BUFFER_INITIALIZER;
+ g_auto(virBuffer) driverChildBuf = VIR_BUFFER_INIT_CHILD(&childBuf);
+
virBufferAsprintf(&attrBuf, " type='%s'", virStorageTypeToString(disk->src->type));
if (disk->src->format > 0)
- virBufferEscapeString(&childBuf, "<driver type='%s'/>\n",
+ virBufferEscapeString(&driverAttrBuf, " type='%s'",
virStorageFileFormatTypeToString(disk->src->format));
+ if (disk->src->metadataCacheMaxSize > 0) {
+ g_auto(virBuffer) metadataCacheChildBuf = VIR_BUFFER_INIT_CHILD(&driverChildBuf);
+
+ virBufferAsprintf(&metadataCacheChildBuf,
+ "<max_size unit='bytes'>%llu</max_size>\n",
+ disk->src->metadataCacheMaxSize);
+
+ virXMLFormatElement(&driverChildBuf, "metadata_cache", NULL, &metadataCacheChildBuf);
+ }
+
+ virXMLFormatElement(&childBuf, "driver", &driverAttrBuf, &driverChildBuf);
+
if (virDomainDiskSourceFormat(&childBuf, disk->src, "source", 0, false, 0,
false, false, xmlopt) < 0)
return -1;
diff --git a/tests/qemudomainsnapshotxml2xmlin/qcow2-metadata-cache.xml b/tests/qemudomainsnapshotxml2xmlin/qcow2-metadata-cache.xml
new file mode 100644
index 0000000000..92440aa0ae
--- /dev/null
+++ b/tests/qemudomainsnapshotxml2xmlin/qcow2-metadata-cache.xml
@@ -0,0 +1,14 @@
+<domainsnapshot>
+ <name>my snap name</name>
+ <description>!@#$%^</description>
+ <disks>
+ <disk name='hdd' snapshot='external'>
+ <source file='/path/to/new'/>
+ <driver type='qcow2'>
+ <metadata_cache>
+ <max_size unit='bytes'>1234</max_size>
+ </metadata_cache>
+ </driver>
+ </disk>
+ </disks>
+</domainsnapshot>
diff --git a/tests/qemudomainsnapshotxml2xmlout/qcow2-metadata-cache.xml b/tests/qemudomainsnapshotxml2xmlout/qcow2-metadata-cache.xml
new file mode 100644
index 0000000000..def2a8ffce
--- /dev/null
+++ b/tests/qemudomainsnapshotxml2xmlout/qcow2-metadata-cache.xml
@@ -0,0 +1,18 @@
+<domainsnapshot>
+ <name>my snap name</name>
+ <description>!@#$%^</description>
+ <creationTime>1386166249</creationTime>
+ <disks>
+ <disk name='hdd' snapshot='external' type='file'>
+ <driver type='qcow2'>
+ <metadata_cache>
+ <max_size unit='bytes'>1234</max_size>
+ </metadata_cache>
+ </driver>
+ <source file='/path/to/new'/>
+ </disk>
+ </disks>
+ <domain>
+ <uuid>9d37b878-a7cc-9f9a-b78f-49b3abad25a8</uuid>
+ </domain>
+</domainsnapshot>
diff --git a/tests/qemudomainsnapshotxml2xmltest.c b/tests/qemudomainsnapshotxml2xmltest.c
index 4b92967339..2a1fe1f52d 100644
--- a/tests/qemudomainsnapshotxml2xmltest.c
+++ b/tests/qemudomainsnapshotxml2xmltest.c
@@ -181,6 +181,9 @@ mymain(void)
DO_TEST_IN("description_only", NULL);
DO_TEST_IN("name_only", NULL);
+ DO_TEST_INOUT("qcow2-metadata-cache", "9d37b878-a7cc-9f9a-b78f-49b3abad25a8",
+ 1386166249, 0);
+
qemuTestDriverFree(&driver);
return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
--
2.29.2
