Re: [libvirt] [PATCH libvirt 1/2] storage: add preallocation element

Allow to specify preallocation mode for QCOW2 images. If not specified or not available, it's ignored. This change only modify the schema, doc, parsing and tests. --- docs/formatstorage.html.in | 6 ++++++ docs/schemas/storagevol.rng | 18 ++++++++++++++++++ src/conf/storage_conf.c | 26 ++++++++++++++++++++++++++ src/conf/storage_conf.h | 1 + src/util/storage_file.c | 4 ++++ src/util/storage_file.h | 10 ++++++++++ tests/storagevolxml2xmlin/vol-qcow2.xml | 1 + tests/storagevolxml2xmlout/vol-qcow2.xml | 1 + 8 files changed, 67 insertions(+) diff --git a/docs/formatstorage.html.in b/docs/formatstorage.html.in index d0e4319..c4faadf 100644 --- a/docs/formatstorage.html.in +++ b/docs/formatstorage.html.in @@ -252,6 +252,12 @@ 1,152,921,504,606,846,976 bytes). <span class="since">Since 0.4.1, multi-character <code>unit</code> since 0.9.11</span></dd> + <dt><code>preallocation</code></dt> + <dd>An image with preallocated metadata is initially larger but + can improve performance when the image needs to grow. This is + supported by QCOW2 image format. + Attribe <code>mode</code> value can be 'off' or 'metadata'. + <span class="since">Since 0.9.13</span></dd> <dt><code>capacity</code></dt> <dd>Providing the logical capacity for the volume. This value is in bytes by default, but a <code>unit</code> attribute can be diff --git a/docs/schemas/storagevol.rng b/docs/schemas/storagevol.rng index 8edb877..d9a148e 100644 --- a/docs/schemas/storagevol.rng +++ b/docs/schemas/storagevol.rng @@ -40,6 +40,7 @@ <ref name='scaledInteger'/> </element> </optional> + <ref name='preallocation'/> </define> <define name='permissions'> @@ -171,6 +172,23 @@ </optional> </define> + <define name='preallocationmode'> + <choice> + <value>off</value> + <value>metadata</value> + </choice> + </define> + + <define name='preallocation'> + <optional> + <element name='preallocation'> + <attribute name='mode'> + <ref name='preallocationmode'/> + </attribute> + </element> + </optional> + </define> + <define name='name'> <data type='string'> <param name="pattern">[a-zA-Z0-9_\+\-\.]+</param> diff --git a/src/conf/storage_conf.c b/src/conf/storage_conf.c index 0b34f28..95849ec 100644 --- a/src/conf/storage_conf.c +++ b/src/conf/storage_conf.c @@ -991,6 +991,7 @@ virStorageVolDefParseXML(virStoragePoolDefPtr pool, char *allocation = NULL; char *capacity = NULL; char *unit = NULL; + char *preallocation = NULL; xmlNodePtr node; options = virStorageVolOptionsForPoolType(pool->type); @@ -1035,6 +1036,19 @@ virStorageVolDefParseXML(virStoragePoolDefPtr pool, ret->allocation = ret->capacity; } + preallocation = virXPathString("string(./preallocation/@mode)", ctxt); + if (preallocation) { + if ((ret->preallocation = virStoragePreallocationModeTypeFromString(preallocation)) < 0) { + virStorageReportError(VIR_ERR_INTERNAL_ERROR, + _("unknown preallocation mode %s"), preallocation); + goto cleanup; + } + + VIR_FREE(preallocation); + } else { + ret->preallocation = VIR_STORAGE_PREALLOCATION_NONE; + } + ret->target.path = virXPathString("string(./target/path)", ctxt); if (options->formatFromString) { char *format = virXPathString("string(./target/format/@type)", ctxt); @@ -1244,6 +1258,18 @@ virStorageVolDefFormat(virStoragePoolDefPtr pool, virBufferAsprintf(&buf," <allocation unit='bytes'>%llu</allocation>\n", def->allocation); + if (def->preallocation != VIR_STORAGE_PREALLOCATION_NONE) { + const char *preallocation; + + preallocation = virStoragePreallocationModeTypeToString(def->preallocation); + if (!preallocation) { + virStorageReportError(VIR_ERR_INTERNAL_ERROR, + "%s", _("unexpected pool type"));

+ goto cleanup; + } + virBufferAsprintf(&buf," <preallocation mode='%s'/>\n", preallocation); + } + if (virStorageVolTargetDefFormat(options, &buf, &def->target, "target") < 0) goto cleanup; diff --git a/src/conf/storage_conf.h b/src/conf/storage_conf.h index 9222c4a..c7c7af0 100644 --- a/src/conf/storage_conf.h +++ b/src/conf/storage_conf.h @@ -98,6 +98,7 @@ struct _virStorageVolDef { virStorageVolSource source; virStorageVolTarget target; virStorageVolTarget backingStore; + int preallocation; /* virStoragePreallocationMode enum */ }; typedef struct _virStorageVolDefList virStorageVolDefList; diff --git a/src/util/storage_file.c b/src/util/storage_file.c index 530071e..8d78d36 100644 --- a/src/util/storage_file.c +++ b/src/util/storage_file.c @@ -47,6 +47,10 @@ VIR_ENUM_IMPL(virStorageFileFormat, "cloop", "cow", "dmg", "iso", "qcow", "qcow2", "qed", "vmdk", "vpc") +VIR_ENUM_IMPL(virStoragePreallocationMode, + VIR_STORAGE_PREALLOCATION_LAST, + "", "off", "metadata") + enum lv_endian { LV_LITTLE_ENDIAN = 1, /* 1234 */ LV_BIG_ENDIAN /* 4321 */ diff --git a/src/util/storage_file.h b/src/util/storage_file.h index 13d0e87..dfc8719 100644 --- a/src/util/storage_file.h +++ b/src/util/storage_file.h @@ -46,6 +46,16 @@ enum virStorageFileFormat { VIR_ENUM_DECL(virStorageFileFormat); +enum virStoragePreallocationMode { + VIR_STORAGE_PREALLOCATION_NONE, + VIR_STORAGE_PREALLOCATION_OFF, + VIR_STORAGE_PREALLOCATION_METADATA, + + VIR_STORAGE_PREALLOCATION_LAST +}; + +VIR_ENUM_DECL(virStoragePreallocationMode); + typedef struct _virStorageFileMetadata { char *backingStore; int backingStoreFormat; diff --git a/tests/storagevolxml2xmlin/vol-qcow2.xml b/tests/storagevolxml2xmlin/vol-qcow2.xml index b4924de..b4c6522 100644 --- a/tests/storagevolxml2xmlin/vol-qcow2.xml +++ b/tests/storagevolxml2xmlin/vol-qcow2.xml @@ -5,6 +5,7 @@ </source> <capacity unit="G">5</capacity> <allocation>294912</allocation> + <preallocation mode='metadata'/> <target> <path>/var/lib/libvirt/images/OtherDemo.img</path> <format type='qcow2'/> diff --git a/tests/storagevolxml2xmlout/vol-qcow2.xml b/tests/storagevolxml2xmlout/vol-qcow2.xml index 4490931..311c52e 100644 --- a/tests/storagevolxml2xmlout/vol-qcow2.xml +++ b/tests/storagevolxml2xmlout/vol-qcow2.xml @@ -5,6 +5,7 @@ </source> <capacity unit='bytes'>5368709120</capacity> <allocation unit='bytes'>294912</allocation> + <preallocation mode='metadata'/> <target> <path>/var/lib/libvirt/images/OtherDemo.img</path> <format type='qcow2'/> -- 1.7.10 -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list