Re: [libvirt] [PATCH] storage: allow metadata preallocation when creating qcow2 images

Currently the 'allocation' element is not used when creating new images with qemu-img. This patch interprets a non-zero value as a request to preallocate metadata when a qcow2 image is created. Bug: https://bugzilla.redhat.com/show_bug.cgi?id=684793 --- src/storage/storage_backend.c | 19 +++++++++++++------ 1 files changed, 13 insertions(+), 6 deletions(-) diff --git a/src/storage/storage_backend.c b/src/storage/storage_backend.c index 41a19a1..bf6f7cc 100644 --- a/src/storage/storage_backend.c +++ b/src/storage/storage_backend.c @@ -669,10 +669,15 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, int imgformat = -1; virCommandPtr cmd = NULL; bool do_encryption = (vol->target.encryption != NULL); + bool preallocate = false; unsigned long long int size_arg; virCheckFlags(0, -1); + /* qcow2: preallocate metadata if requested allocation is non-zero */ + if (vol->allocation > 0 && vol->target.format == VIR_STORAGE_FILE_QCOW2) + preallocate = true; + const char *type = virStorageFileFormatTypeToString(vol->target.format); const char *backingType = vol->backingStore.path ? virStorageFileFormatTypeToString(vol->backingStore.format) : NULL;> @@ -842,12 +847,14 @@ virStorageBackendCreateQemuImg(virConnectPtr conn, vol->target.path, NULL); virCommandAddArgFormat(cmd, "%lluK", size_arg); - if (do_encryption) { - if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS) { - virCommandAddArgList(cmd, "-o", "encryption=on", NULL); - } else { - virCommandAddArg(cmd, "-e"); - } + if (imgformat == QEMU_IMG_BACKING_FORMAT_OPTIONS && + (do_encryption || preallocate)) { + virCommandAddArg(cmd, "-o"); + virCommandAddArgFormat(cmd, "%s%s%s", do_encryption ? "encryption=on" : "", + (do_encryption && preallocate) ? "," : "", + preallocate ? "preallocation=metadata" : ""); + } else if (do_encryption){ + virCommandAddArg(cmd, "-e"); } }